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焦化氣發(fā)電機組的煤氣的初冷和焦油的回收
Initial cooling of coal gas and recovery of tar in coking gas generator units
荒煤氣的主要成分有凈焦爐煤氣、水蒸氣、煤焦油氣、苯族烴、氨、萘、硫化氫、其他硫化物、氰化氫等氰化物、吡啶鹽等。
The main components of raw coal gas include clean coke oven gas, steam, coal coke oil and gas, benzene hydrocarbons, ammonia, naphthalene, hydrogen sulfide, other sulfides, cyanide such as hydrogen cyanide, pyridines, etc.
回收煉焦化學(xué)產(chǎn)品具有重要的意義。煤在煉焦時,除有75%左右變成焦炭外,還有25%左右生成多種化學(xué)產(chǎn)品及煤氣。來自焦爐的荒煤氣,經(jīng)冷卻和用各種吸收劑處理后,可以提取出煤焦油、氨、萘、硫化氫、氰化氫及粗苯等化學(xué)產(chǎn)品,并得到凈焦爐煤氣,氨可以用于制取硫酸銨和無水氨;煤氣中所含的氫可用于制造合成氨、合成甲醇、雙氧水、環(huán)己烷等,合成氨可進一步制成硫酸銨等化肥;所含的乙烯可用于制取乙醇和三氯乙烷的原料,硫化氫是生產(chǎn)單質(zhì)硫和元素硫的原料,氰化氫可用于制取黃血鹽鈉或黃血鹽鉀;粗苯和煤焦油都是很復(fù)雜的半成品,經(jīng)精制加工后,可得到的產(chǎn)品有:二硫化碳、苯、甲苯、三甲苯、古馬隆、酚、甲酚和吡啶鹽及瀝青等,這些產(chǎn)品有廣泛的用途,是合成纖維、塑料、染料、合成橡膠、醫(yī)藥、農(nóng)藥、耐輻射材料、耐高溫材料以及國防工業(yè)的重要原料。
The recycling of coking chemical products is of great significance. During coking, about 75% of coal is converted into coke, and another 25% is used to produce various chemical products and coal gas. The raw gas from coke ovens can be cooled and treated with various absorbents to extract chemical products such as coal tar, ammonia, naphthalene, hydrogen sulfide, hydrogen cyanide, and crude benzene, and obtain clean coke oven gas. Ammonia can be used to produce ammonium sulfate and anhydrous ammonia; The hydrogen contained in coal gas can be used to produce synthetic ammonia, synthetic methanol, hydrogen peroxide, cyclohexane, etc. Synthetic ammonia can be further used to produce fertilizers such as ammonium sulfate; The ethylene contained can be used as a raw material for producing ethanol and trichloroethane, hydrogen sulfide is a raw material for producing elemental sulfur and elemental sulfur, and hydrogen cyanide can be used to produce sodium or potassium yellow blood salt; Crude benzene and coal tar are both complex semi-finished products that can be refined and processed to obtain products such as carbon disulfide, benzene, toluene, trimethylbenzene, coumarin, phenol, cresol, pyridinium salts, and asphalt. These products have a wide range of applications and are important raw materials for synthetic fibers, plastics, dyes, synthetic rubber, pharmaceuticals, pesticides, radiation resistant materials, high-temperature resistant materials, and defense industries.
回收工藝的組成為:焦爐炭化室生成的荒煤氣在化學(xué)產(chǎn)品回收車間進行冷卻、輸送、回收煤焦油、氨、硫、苯族烴等化學(xué)產(chǎn)品,同時凈化煤氣。化產(chǎn)回收車間一般由冷凝鼓風(fēng)工段、HPF脫硫工段、硫銨工段、終冷洗苯工段、粗苯蒸餾工段等工段組成。
The composition of the recycling process is as follows: the raw coal gas generated in the coking chamber of the coke oven is cooled, transported, and recycled in the chemical product recycling workshop to produce chemical products such as coal tar, ammonia, sulfur, and benzene hydrocarbons, while purifying the gas. The chemical recovery workshop generally consists of condensing and blowing section, HPF desulfurization section, ammonium sulfate section, final cold washing benzene section, crude benzene distillation section and other sections.
冷凝工段
Condensation section
1、煤氣的初冷和焦油氨水的分離
1. Initial cooling of coal gas and separation of tar and ammonia water
2、煤氣初冷的目的一是冷卻煤氣,二是使焦油和氨水分離,并脫除焦油渣。
2. The purpose of initial gas cooling is twofold: firstly, to cool the gas; secondly, to separate tar and ammonia water, and to remove tar residue.
在煉焦過程中,從焦爐碳化室經(jīng)上升管逸出的粗煤氣溫度為650~750℃,首先經(jīng)過初冷,將煤氣溫度降至25~35℃,粗煤氣中所含的大部分水汽、焦油氣、萘及固體微粒被分離出來,部分硫化氫和氰化氫等腐蝕性物質(zhì)溶于冷凝液中,從而可減少回收設(shè)備及管道的堵塞和腐蝕;煤氣經(jīng)初冷后,體積變小,從而使鼓風(fēng)機以較小的動力消耗將煤氣送往后續(xù)的凈化工序;煤氣經(jīng)出冷后,溫度降低,是保證煉焦化學(xué)產(chǎn)品回收率和質(zhì)量的先決條件。
During the coking process, the temperature of the crude gas escaping from the carbonization chamber of the coke oven through the riser is 650-750 ℃. Firstly, it is cooled down to 25-35 ℃, and most of the water vapor, tar gas, naphthalene, and solid particles contained in the crude gas are separated. Some corrosive substances such as hydrogen sulfide and cyanide dissolve in the condensate, thereby reducing the blockage and corrosion of recovery equipment and pipelines; After initial cooling, the volume of gas decreases, allowing the blower to send the gas to the subsequent purification process with less power consumption; After the gas is cooled, the temperature decreases, which is a prerequisite for ensuring the recovery rate and quality of coking chemical products.
煤氣的初冷分為集氣管冷卻和初冷器冷卻兩個步驟。
The initial cooling of gas is divided into two steps: gas collection pipe cooling and primary cooler cooling.
1.1煤氣在集氣管內(nèi)的冷卻
1.1 Cooling of Gas in Gas Collecting Pipeline
煤氣在集氣管內(nèi)冷卻機理
Cooling mechanism of gas in the gas collection pipeline
煤氣在橋管和集氣管內(nèi)的冷卻,是用表壓為147~196Kpa,溫度為70~75℃的循環(huán)氨水通過噴頭強烈噴灑進行的。當細霧狀的氨水與煤氣充分接觸時,由于煤氣溫度很高而濕度又很低,故煤氣放出大量的顯熱,氨水大量蒸發(fā),快速進行著傳熱和傳質(zhì)過程。傳熱過程取決于煤氣與氨水的溫度差,所傳遞的熱量為顯熱,約占煤氣冷卻所放出總熱量的10%~15%。傳質(zhì)過程的推動力是循環(huán)氨水液面上的蒸汽分壓與煤氣中蒸汽分壓之差,氨水部分蒸發(fā),煤氣溫度急劇降低,以供給氨水蒸發(fā)所需的潛熱,此部分熱量約占煤氣冷卻所放出熱量的75%~80%。另有約占所放出總熱量10%的熱量由集氣管表面散失。
The cooling of gas in the bridge pipe and gas collection pipe is carried out by vigorously spraying circulating ammonia water with a gauge pressure of 147-196Kpa and a temperature of 70-75 ℃ through a nozzle. When the fine mist like ammonia water comes into full contact with the gas, due to the high temperature and low humidity of the gas, a large amount of sensible heat is released from the gas, and the ammonia water evaporates rapidly, carrying out heat and mass transfer processes. The heat transfer process depends on the temperature difference between gas and ammonia water, and the heat transferred is sensible heat, accounting for about 10% to 15% of the total heat released by gas cooling. The driving force of mass transfer process is the difference between the vapor partial pressure on the circulating ammonia water surface and the vapor partial pressure in the gas. The ammonia water partially evaporates, and the gas temperature drops sharply to supply the latent heat required for ammonia water evaporation. This part of the heat accounts for about 75% to 80% of the heat released by gas cooling. About 10% of the total heat released is dissipated from the surface of the gas collection pipe.
通過上述冷卻過程,煤氣溫度由800℃左右降至82~86℃,同時由60%左右的焦油氣冷凝下來,這是重質(zhì)焦油部分。在實際生產(chǎn)過程中,煤氣溫度可冷卻至25℃。(高于其最后達到的露點溫度1~3℃)
Through the above cooling process, the gas temperature drops from around 800 ℃ to 82-86 ℃, while about 60% of the tar gas is condensed, which is the heavy tar portion. In the actual production process, the gas temperature can be cooled to 25 ℃. (1-3 ℃ higher than its final dew point temperature)
1.2 煤氣在初冷器內(nèi)的冷卻
1.2 Cooling of Gas in the Primary Cooler
焦爐煤氣由集氣管沿吸煤氣主管流向煤氣初冷器。吸煤氣主管除將煤氣由焦爐引向化產(chǎn)回收裝置外,還起著空氣冷卻器的作用,煤氣可降溫1~3℃。
Coke oven gas flows from the gas collection pipe along the main gas suction pipe to the gas primary cooler. The main gas suction pipe not only directs the gas from the coke oven to the chemical recovery unit, but also serves as an air cooler, which can cool the gas by 1-3 ℃.
煤氣進入初冷器的溫度仍然很高,達82℃左右,而且含有大量蒸汽和焦油氣,須在初冷器中冷卻到25~35℃,并將大部分焦油氣和蒸汽冷凝下來。
The temperature of the gas entering the primary cooler is still very high, reaching around 82 ℃, and it contains a large amount of steam and tar gas. It needs to be cooled to 25-35 ℃ in the primary cooler and most of the tar gas and steam need to be condensed.
根據(jù)采用的初冷主體設(shè)備型式的不同,初冷的方法有間接初冷法、直接初冷法和間接直接初冷法之分。
According to the different types of primary cooling equipment used, there are three methods of primary cooling: indirect primary cooling, direct primary cooling, and indirect direct primary cooling.
煤氣初冷工藝控制的關(guān)鍵操作指標,就是初冷后煤氣的出口溫度。
The key operational indicator for controlling the initial cooling process of gas is the outlet temperature of the gas after initial cooling.
?。?)煤氣中蒸汽含量增多,體積變大,致使鼓風(fēng)機能力不足,影響煤氣正常輸送。
(1) The increase in steam content and volume in gas leads to insufficient blower capacity, affecting the normal transportation of gas.
?。?)焦油氣凝結(jié)率低,初冷后煤氣中焦油含量增多,影響以后的工序操作。
(2) The low condensation rate of tar gas leads to an increase in tar content in the gas after initial cooling, which affects subsequent process operations.
(3)當出口溫度高時,煤氣中萘含量將更顯著增大。這會造成煤氣管道和設(shè)備堵塞,增加以后洗萘系統(tǒng)負荷,給洗氨、洗苯帶來困難。
(3) When the outlet temperature is high, the naphthalene content in the gas will increase more significantly. This will cause blockages in gas pipelines and equipment, increase the load on the naphthalene washing system in the future, and pose difficulties for ammonia and benzene washing.
因此,在煤氣初冷器中,必須保證初冷后集合溫度不高于規(guī)定值,并盡可能低脫除煤氣中的萘。
Therefore, in the gas primary cooler, it is necessary to ensure that the collection temperature after initial cooling does not exceed the specified value, and to remove naphthalene from the gas as low as possible.
1.3 煤氣的初冷流程
1.3 Initial cooling process of gas
焦油煤氣與噴灑氨水、冷凝焦油等沿吸煤氣主管首先進入氣液分離器,煤氣與焦油、氨水、焦油渣等在此分離。分離出來的焦油、氨水和焦油渣一起進入焦油氨水分離槽,經(jīng)過澄清分成三層:上層為氨水;中層為焦油;下層為焦油渣。沉淀下來的焦油渣由刮板輸送機連續(xù)刮送至漏斗處排出槽外,有小車定期送往煤場。焦油則通過液面調(diào)節(jié)器流至氨水中間槽,由此泵往油庫工段焦油貯槽。氨水由分離槽上部流至氨水中間槽,再用循環(huán)氨水泵送回焦爐集氣管以冷卻粗煤氣,這部分氨水稱之為循環(huán)氨水。
Tar gas, sprayed ammonia water, condensed tar, etc. first enter the gas-liquid separator along the main gas suction pipe, where the gas is separated from tar, ammonia water, tar residue, etc. The separated tar, ammonia water, and tar residue enter the tar ammonia water separation tank together, and after clarification, they are divided into three layers: the upper layer is ammonia water; The middle layer is tar; The lower layer is tar residue. The precipitated tar residue is continuously scraped by a scraper conveyor to the funnel and discharged outside the trough, and is regularly transported to the coal yard by a small car. Tar flows through the liquid level regulator to the ammonia intermediate tank, and is then pumped to the tar storage tank in the oil depot section. Ammonia water flows from the upper part of the separation tank to the intermediate tank, and is then pumped back to the coke oven gas collection pipe by a circulating ammonia water pump to cool the crude gas. This part of ammonia water is called circulating ammonia water.
經(jīng)氣液分離后的煤氣進入橫管式初冷器,橫管式初冷器煤氣通道,一般上段用循環(huán)氨水噴灑,下段用冷凝液噴灑。上段冷凝液從隔斷板經(jīng)水封自流至氨水分離器,下段冷凝液經(jīng)水封自流至冷凝液槽。下段冷凝液主要是輕質(zhì)焦油,作為下段噴灑液有利于洗萘。突出特點是橫管式初冷器的熱負荷顯著降低,冷卻水用量大為減少。
After gas-liquid separation, the coal gas enters the horizontal tube primary cooler. The gas channel of the horizontal tube primary cooler is generally sprayed with circulating ammonia water in the upper section and condensed liquid in the lower section. The upper condensate flows from the partition plate to the ammonia separator through the water seal, while the lower condensate flows to the condensate tank through the water seal. The main component of the lower condensate is light tar, which is beneficial for washing naphthalene as the lower spray liquid. The prominent feature is that the heat load of the horizontal tube primary cooler is significantly reduced, and the amount of cooling water used is greatly reduced.
隨著煤氣的冷卻,煤氣中剩余的絕大部分的焦油氣、蒸汽和萘在初冷器中被冷卻下來,萘溶解于焦油中。煤氣中一定數(shù)量的氨、二氧化碳、硫化氫、氰化氫和其他組分溶解于冷凝水中,形成了冷凝氨水。焦油和冷凝氨水的混合液稱為冷凝液。冷凝氨水中含有較多的揮發(fā)銨鹽,固定銨鹽的含量較少。循環(huán)氨水中則主要含有固定銨鹽,在單獨循環(huán)使用時,固定銨鹽含量可高達30~40g/L。為了降低循環(huán)氨水中固定銨鹽的含量,以減輕對焦油蒸餾設(shè)備的腐蝕和改善焦油的脫水、脫鹽操作,大多采用兩種氨水混合的流程,混合氨水固定銨鹽的含量可降至1.3~3.5 g/L。冷凝液自流入冷凝液槽,再用泵送入機械化刮渣槽,與澄清氨水混合液澄清分離。分離后所得剩余氨水送去脫酚和蒸氨。
As the gas cools, the majority of the remaining tar gas, steam, and naphthalene in the gas are cooled down in the primary cooler, and naphthalene dissolves in the tar. A certain amount of ammonia, carbon dioxide, hydrogen sulfide, hydrogen cyanide, and other components in coal gas dissolve in condensate water, forming condensate ammonia water. The mixture of tar and condensed ammonia water is called condensate. Condensed ammonia water contains more volatile ammonium salts and less fixed ammonium salts. The circulating ammonia water mainly contains fixed ammonium salts, and when used separately, the content of fixed ammonium salts can be as high as 30-40 g/L. In order to reduce the content of fixed ammonium salts in circulating ammonia water, alleviate the corrosion of tar distillation equipment, and improve the dehydration and desalination operations of tar, a process of mixing two types of ammonia water is mostly adopted. The content of fixed ammonium salts in mixed ammonia water can be reduced to 1.3-3.5 g/L. The condensate flows into the condensate tank and is then pumped into the mechanized scraper tank for clarification and separation with the clarified ammonia water mixture. The remaining ammonia water obtained after separation is sent for dephenolization and ammonia distillation.
由橫管式初冷器出來的煤氣尚含有1.5~2g/m3的霧狀焦油,被鼓風(fēng)機抽送至電捕焦油器除去絕大部分焦油霧后,送往下一道工序。
The gas from the horizontal tube primary cooler still contains 1.5-2g/m3 of misty tar, which is pumped by a blower to an electric tar catcher to remove the majority of tar mist before being sent to the next process.
1.4 焦油氨水的分離
1.4 Separation of Tar Ammonia Water
用循環(huán)氨水在集氣管內(nèi)噴灑粗煤氣時,約60%的焦油冷凝下來,這種焦油是重質(zhì)焦油,黏度較大,其中混有一定數(shù)量的焦油渣。焦油渣內(nèi)含有煤塵、焦粉、炭化室頂部熱解產(chǎn)生的游離炭及清掃上升管和集氣管時所帶入的多孔物質(zhì),其量約占焦油渣的30%,其余約70%為焦油。焦油渣量一般為焦油質(zhì)量的0.15%~0.3%。
When using circulating ammonia water to spray crude coal gas in the gas collection pipe, about 60% of the tar condenses. This tar is heavy tar with high viscosity and contains a certain amount of tar residue. Tar residue contains coal dust, coke powder, free carbon produced by pyrolysis at the top of the carbonization chamber, and porous substances brought in during the cleaning of the riser and gas collection pipe. Its amount accounts for about 30% of the coke residue, and the remaining 70% is tar. The amount of tar residue is generally 0.15% to 0.3% of the tar mass.
焦油渣內(nèi)固定碳含量約為60%,因其與集氣管焦油的密度差小,密度小,易于焦油黏附在一起,所以難分離。
The fixed carbon content in tar residue is about 60%, and it is difficult to separate due to its small density difference with the tar in the gas collection pipe, which makes it easy for tar to adhere together.
在兩種氨水混合分離流程中,初冷器輕質(zhì)焦油和上述重質(zhì)焦油混合后,20℃,密度可降至1.15~1.19Kg/L,黏度比重質(zhì)焦油減少20%~45%,焦油渣易于沉淀下來,混合焦油質(zhì)量明顯改善。但在焦油中仍存在一些浮焦油渣,給焦油分離帶來困難。
In the two ammonia water mixing and separation processes, after mixing the light tar from the primary cooler with the heavy tar mentioned above, the density can be reduced to 1.15-1.19Kg/L at 20 ℃, and the viscosity can be reduced by 20% -45% compared to the heavy tar. The tar residue is easy to precipitate, and the quality of the mixed tar is significantly improved. However, there are still some floating tar residues in the tar, which pose difficulties for tar separation.
經(jīng)澄清分離后的循環(huán)氨水中,焦油物質(zhì)含量越低越好,最好不超過100mg/L.
The lower the tar content in the clarified and separated circulating ammonia water, the better, preferably not exceeding 100mg/L
1.5 煤氣中焦油霧的清除
1.5 Removal of Tar Mist from Gas
焦油霧是在煤氣冷卻過程中形成的,它以內(nèi)充煤氣的焦油氣泡狀態(tài)或極細小的焦油滴存在于煤氣中。由于焦油霧又輕又小,其沉降速度小于煤氣流速,因而懸浮于煤氣中并被煤氣帶走。
Tar mist is formed during the cooling process of coal gas, and it exists in the form of tar bubbles or extremely small tar droplets filled with coal gas. Due to the light and small nature of tar mist, its settling velocity is lower than the gas flow rate, so it is suspended in the gas and carried away by the gas.
初冷器后煤氣中焦油霧的含量一般為2~5g/m3。鼓風(fēng)機后煤氣中焦油霧的含量一般為0.3~0.5g/m3?;a(chǎn)回收工藝要求煤氣中焦油霧的含量低于0.02 g/m3,否則對化產(chǎn)回收操作將有嚴重影響。
The content of tar mist in the gas after the primary cooler is generally 2-5g/m3. The content of tar mist in the gas after the blower is generally 0.3-0.5g/m3. The chemical recovery process requires the tar mist content in the gas to be less than 0.02 g/m3, otherwise it will have a serious impact on the chemical recovery operation.
2、冷凝鼓風(fēng)工段工藝流程:
2. Process flow of condensing and blowing section:
煉焦過程中產(chǎn)生的荒煤氣匯集到炭化室頂部空間,經(jīng)上升管、橋管進入集氣管。約800℃左右的荒煤氣在橋管內(nèi)被循環(huán)氨水噴灑冷卻到85℃左右?;拿簹庵械慕褂偷韧瑫r被冷卻下來,焦油和氨水一起沿吸煤氣管道至氣液分離器,氣液分離后荒煤氣由上部出來,進入橫管初冷器。在此分循環(huán)水段、低溫水段兩段冷卻。循環(huán)水段用32°C循環(huán)水與煤氣換熱,低溫水段用16°C低溫水將煤氣冷卻至25°C。由橫管初冷器下部排出的煤氣,進入電捕焦油器,除掉煤氣中夾帶的焦油,經(jīng)脫硫裝置脫硫后,再由鼓風(fēng)機壓送至硫銨裝置。
The raw gas generated during the coking process is collected in the top space of the carbonization chamber and enters the gas collection pipe through the riser and bridge pipe. The raw gas at around 800 ℃ is cooled to around 85 ℃ by circulating ammonia water spraying inside the bridge pipe. The tar and other substances in the raw gas are simultaneously cooled down, and the tar and ammonia water flow along the gas suction pipeline to the gas-liquid separator. After gas-liquid separation, the raw gas comes out from the upper part and enters the horizontal tube primary cooler. Here, it is divided into two cooling stages: circulating water stage and low-temperature water stage. The circulating water section uses 32 ° C circulating water to exchange heat with the gas, while the low-temperature water section uses 16 ° C low-temperature water to cool the gas to 25 ° C. The gas discharged from the lower part of the horizontal tube primary cooler enters the electric tar catcher to remove the tar carried in the gas. After desulfurization by the desulfurization device, it is then pressurized by the blower to the ammonium sulfate device.
為了保證初冷器冷卻及除萘效果,在循環(huán)水段采用乳化液泵噴灑焦油、氨水的乳化液、在低溫水段連續(xù)噴灑焦油、氨水混合液,在其頂部用熱氨水定期沖洗,以清除管壁上的焦油、萘等雜質(zhì)。
In order to ensure the cooling and naphthalene removal effect of the primary cooler, an emulsion pump is used to spray tar and ammonia emulsion in the circulating water section, and a mixture of tar and ammonia is continuously sprayed in the low-temperature water section. The top is regularly rinsed with hot ammonia water to remove impurities such as tar and naphthalene from the pipe wall.
初冷器循環(huán)水段的冷凝液排入機械刮渣槽。
The condensate from the circulating water section of the primary cooler is discharged into the mechanical scraper tank.
初冷器低溫水段排出的冷凝液經(jīng)水封槽流入冷凝液槽,加兌一定量焦油、氨水乳化液后,用泵將其送入初冷器低溫水段循環(huán)噴灑。
The condensate discharged from the low-temperature water section of the primary cooler flows into the condensate tank through the water seal tank. After adding a certain amount of tar and ammonia emulsion, it is pumped into the low-temperature water section of the primary cooler for circulation and spraying.
由氣液分離器分離下來的焦油、氨水進入機械刮渣槽,在此進行氨水、焦油和焦油渣的分離,氨水和焦油自流入焦油氨水分離槽,焦油渣排入焦油渣小車,定期送往煤場。
The tar and ammonia water separated by the gas-liquid separator enter the mechanical scraper tank, where ammonia water, tar, and tar slag are separated. Ammonia water and tar flow into the tar ammonia water separation tank, and the tar slag is discharged into the tar slag trolley and regularly sent to the coal yard.
焦油氨水分離槽上部的氨水自流入下部槽內(nèi),再由循環(huán)氨水泵送至焦爐集氣管噴灑冷卻煤氣,剩余氨水自流入剩余氨水槽,經(jīng)氣浮除焦油器脫除焦油后,送至蒸氨裝置處理。焦油氨水分離槽下部的焦油通過溢流瓶自流入焦油中間槽,用焦油泵送油庫。焦油氨水分離槽底部的焦油渣用焦油渣泵送機械刮渣槽。
The ammonia water from the upper part of the tar ammonia water separation tank flows into the lower tank by itself, and is then pumped by the circulating ammonia water pump to the coke oven gas collection pipe to spray and cool the gas. The remaining ammonia water flows into the remaining ammonia water tank by itself, and after removing tar through the gas flotation tar remover, it is sent to the ammonia distillation unit for treatment. The tar in the lower part of the tar ammonia separation tank flows into the tar intermediate tank through the overflow bottle and is pumped to the oil depot by the tar pump. The tar residue at the bottom of the tar ammonia separation tank is pumped to the mechanical scraping tank using a tar residue pump.
3、工藝特點
3. Process characteristics
1)初冷器采用高效橫管冷卻器,將煤氣冷卻到~25°C,使煤氣中的大部分萘通過冷卻脫除,確保后序設(shè)備無堵塞之患。
1) The primary cooler adopts an efficient transverse tube cooler to cool the gas to~25 ° C, which removes most of the naphthalene in the gas through cooling and ensures that the subsequent equipment is not blocked.
2)橫管冷卻器中間帶斷塔盤結(jié)構(gòu),節(jié)約了低溫水用量,降低了操作費用。
2) The horizontal tube cooler has a broken tray structure in the middle, which saves the amount of low-temperature water and reduces operating costs.
3)采用新型高效的蜂窩式電捕焦油器,處理后煤氣中焦油可控制在50mg/m3以下,有利于后序設(shè)備的正常操作。
3) By using a new and efficient honeycomb type electric tar catcher, the tar in the treated gas can be controlled below 50mg/m3, which is beneficial for the normal operation of subsequent equipment.
4)采用串聯(lián)剩余氨水槽靜止沉淀和氨水氣浮除焦油器除渣除油,降低剩余氨水含油量,有利于蒸氨正常操作。
4) The use of a series of residual ammonia water tanks for static precipitation and an ammonia water flotation tar remover for slag and oil removal reduces the oil content of residual ammonia water, which is beneficial for the normal operation of ammonia distillation.
5) 高壓氨水泵采用變頻調(diào)速。
5) The high-pressure ammonia water pump adopts variable frequency speed regulation.
6) 電捕焦油器蜂窩管為不銹鋼材質(zhì)。
6) The honeycomb tube of the electric tar catcher is made of stainless steel material.
7)煤氣鼓風(fēng)機采用帶液力偶合器的高效低耗的電動煤氣鼓風(fēng)機,使煤氣鼓風(fēng)機可根據(jù)煤氣量實現(xiàn)無級調(diào)速,適合焦化廠煤氣量周期性波動的特點,并可實現(xiàn)鼓風(fēng)機前吸煤氣管道壓力自動調(diào)節(jié)。同時操作調(diào)節(jié)靈活,高效節(jié)能。
7) The gas blower adopts an efficient and low consumption electric gas blower with a hydraulic coupling, which enables the gas blower to achieve stepless speed regulation according to the gas volume, suitable for the periodic fluctuation of gas volume in coking plants, and can automatically adjust the pressure of the gas suction pipeline before the blower. Simultaneously operate and adjust flexibly, efficient and energy-saving.
4、主要技術(shù)操作指標
4. Main technical operation indicators
初冷器后煤氣溫度~25℃
Gas temperature after primary cooler~25 ℃
初冷器循環(huán)水入口溫度32℃
Initial cooler circulating water inlet temperature 32 ℃
初冷器循環(huán)水出口溫度45℃
Initial cooler circulating water outlet temperature 45 ℃
初冷器低溫水入口溫度16℃
The inlet temperature of low-temperature water in the primary cooler is 16 ℃
初冷器低溫水出口溫度23℃
Low temperature water outlet temperature of primary cooler 23 ℃
電捕焦油器絕緣箱溫度80~100℃
Insulation box temperature of electric tar catcher 80-100 ℃
初冷器阻力1.5kPa
Initial cooler resistance 1.5kPa
電捕焦油器阻力0.5kPa
Electric tar catcher resistance 0.5kPa
5、主要環(huán)保措施
5. Main environmental protection measures
1)焦油渣回兌煉焦煤中,廢渣不外排。
1) Tar residue is mixed with coking coal, and the waste residue is not discharged.
2)貯槽放散氣體經(jīng)壓力平衡系統(tǒng)回吸煤氣管道,廢氣不外排。
2) The gas released from the storage tank is sucked back into the gas pipeline through the pressure balance system, and the exhaust gas is not discharged outside.
3)設(shè)備放空液、泵漏液經(jīng)地下放空槽送回吸煤氣管道,廢水不外排。
3) The equipment venting liquid and pump leakage liquid are sent back to the gas suction pipeline through the underground venting tank, and the wastewater is not discharged outside.
6、主要設(shè)備的工作原理
6. Working principle of main equipment
離心式鼓風(fēng)機
Centrifugal blower
離心式鼓風(fēng)機又稱渦輪式鼓風(fēng)機,由汽輪機或電動機驅(qū)動。
Centrifugal blower, also known as turbine blower, is driven by a steam turbine or an electric motor.
離心式鼓風(fēng)機由導(dǎo)葉輪、外殼和安裝在軸上的工作葉輪所組成。煤氣由鼓風(fēng)機吸入后做高速旋轉(zhuǎn)于轉(zhuǎn)子的第一個工作葉輪中心,煤氣在離心力的作用下被甩到殼體的環(huán)形空隙中心處即產(chǎn)生減壓,煤氣就不斷的被吸入,離開葉輪時煤氣速度很高,當進入環(huán)形空隙中,其動壓頭一部分轉(zhuǎn)變?yōu)殪o壓頭,煤氣的運動速度減小,并通過導(dǎo)管進入第二個葉輪,產(chǎn)生與第一葉輪相同的作用,煤氣的靜壓頭再次被提高。從最后一個葉輪出來的煤氣由殼體的環(huán)形空隙流入出口連接管被送入壓出管路中。
A centrifugal blower consists of a guide impeller, a casing, and a working impeller installed on the shaft. After being sucked in by the blower, the gas rotates at high speed at the center of the first working impeller of the rotor. Under the action of centrifugal force, the gas is thrown to the center of the annular gap of the shell, which produces pressure reduction. The gas is continuously sucked in and leaves the impeller at a high speed. When it enters the annular gap, a part of its dynamic pressure head is converted into a static pressure head, and the velocity of the gas decreases. It enters the second impeller through the conduit, producing the same effect as the first impeller, and the static pressure head of the gas is increased again. The gas coming out of the last impeller flows into the outlet connecting pipe through the annular gap of the shell and is sent into the extrusion pipeline.
煤氣輸送借助鼓風(fēng)機將煤氣由焦爐吸出,現(xiàn)代使用的鼓風(fēng)機總壓頭為30~36KPa,經(jīng)鼓風(fēng)機增壓后,由于絕熱壓縮煤氣升溫10~15℃。煤氣鼓風(fēng)機正常操作是焦化廠生產(chǎn)的關(guān)鍵,它既要輸送煤氣,又要保持炭化室和集氣管的壓力穩(wěn)定,所以必須精心操作和養(yǎng)護。機體下部凝結(jié)的焦油和水要及時排出。
Gas transportation uses a blower to extract gas from the coke oven. The total pressure head of modern blowers is 30-36KPa. After being pressurized by the blower, the gas is heated by 10-15 ℃ due to adiabatic compression. The normal operation of the gas blower is crucial for the production of coking plants. It not only needs to transport gas, but also maintain stable pressure in the carbonization chamber and gas collection pipe, so it must be carefully operated and maintained. Tar and water condensed in the lower part of the body should be promptly discharged.
為什么要在焦化廠煤氣流程內(nèi)設(shè)置鼓風(fēng)機?
Why is it necessary to install a blower in the gas process of a coking plant?
從煉焦爐出來的焦爐煤氣,經(jīng)集氣管、吸氣管、初冷器、捕焦油器、回收氨和苯的系統(tǒng)等一系列的設(shè)備,然后才能變成凈煤氣送給不同的用戶,或送至貯罐。在這一過程中煤氣要克服許多阻力才能達用戶的地點,為此煤氣應(yīng)具有足夠的剩余壓力。另外,為了使焦爐內(nèi)的荒煤氣按規(guī)定的壓力制度抽出,要使煤氣管線中具有一定的吸力。因此,必須在焦化工藝的流程中,選擇合理的位置設(shè)置鼓風(fēng)機,使地級前為負壓,機后為正壓,一般焦化廠鼓風(fēng)機的位置選擇在初冷器之后和電捕焦油器之前,這是因為此時鼓風(fēng)機的負荷較小,電捕焦油器處于正壓狀態(tài)下操作,比較安全。
The coke oven gas from the coke oven can only be converted into clean gas and sent to different users or storage tanks after passing through a series of equipment such as gas collection pipes, suction pipes, primary coolers, tar catchers, and systems for recovering ammonia and benzene. In this process, the gas must overcome many resistance to reach the user's site, so the gas should have sufficient residual pressure. In addition, in order to extract the raw gas from the coke oven according to the prescribed pressure system, it is necessary to provide a certain suction force in the gas pipeline. Therefore, it is necessary to choose a reasonable position to set up the blower in the coking process, so that the ground level front is negative pressure and the rear is positive pressure. Generally, the position of the blower in coking plants is chosen after the primary cooler and before the electric tar precipitator. This is because the load on the blower is small at this time, and the electric tar precipitator is operated under positive pressure, which is relatively safe.
橫管式初冷器
Horizontal tube primary cooler
焦化系統(tǒng)生產(chǎn)中煤氣橫管式初冷器主要結(jié)構(gòu)是包括初冷器殼體、冷卻管管束。橫管式初冷器殼體是由鋼板焊制而成的直立的長方形器體,殼體的前后兩側(cè)是初冷器的管板,管板外裝有封頭。在殼體側(cè)面上、中部有噴灑液接管,頂部為煤氣入口,底部有煤氣出口。在橫管式初冷器的操作中,除了冷卻焦爐煤氣外,在冷卻器頂部及中部噴灑冷凝液,來吸收焦爐煤氣中的萘,并沖刷掉冷卻管上沉積的萘,從而有效的提高了傳熱效率。初冷器后的煤氣含焦油和水的霧滴,在鼓風(fēng)機的離心力作用下大部分以液態(tài)析出,余下部分在電捕焦油器的電場作用下沉淀下來。
In the production of coking system, the main structure of gas horizontal tube primary cooler is composed of primary cooler shell and cooling tube bundle. The shell of the horizontal tube primary cooler is an upright rectangular body welded from steel plates. The front and rear sides of the shell are the tube plates of the primary cooler, which are equipped with heads on the outside. There are spray nozzles on the side and middle of the shell, with a gas inlet at the top and a gas outlet at the bottom. In the operation of the horizontal tube primary cooler, in addition to cooling the coke oven gas, condensate is sprayed at the top and middle of the cooler to absorb naphthalene in the coke oven gas and flush out the naphthalene deposited on the cooling tube, effectively improving heat transfer efficiency. The gas after the primary cooler contains tar and water droplets, most of which precipitate in liquid form under the centrifugal force of the blower, and the remaining part precipitates under the electric field of the electric tar catcher.
初冷器后的粗煤氣質(zhì)量減少了2/3,而容積減少了3/5,從而減少了繼續(xù)輸送的電能消耗。
The quality of the crude gas after the primary cooler has decreased by 2/3, while the volume has decreased by 3/5, thereby reducing the consumption of electricity for continued transmission.
電捕焦油器
Electric tar catcher
電捕焦油器的沉淀管為沉淀極,與電流正極相接,電暈導(dǎo)線為電暈極,與電源負極相接,當導(dǎo)入高壓直流電流后,兩極之間形成非均勻電場,電暈極周圍成為電暈區(qū)產(chǎn)生電暈現(xiàn)象,電暈極附近氣體發(fā)生撞擊電離現(xiàn)象,電暈區(qū)內(nèi)煤氣分子變策劃能夠帶陽電離子和帶陰電離子,電暈區(qū)外充滿帶負電荷的離子,它附與煤氣中的焦油霧滴上,使焦油霧粒向沉淀管內(nèi)壁上移動,沉淀壁面上,沿壁以重力下降到電捕焦油器底部,由于沉淀極是接地的,把電子導(dǎo)入地下,煤氣離子重新變成中性分子,從器頂離開電捕焦油器。
The sedimentation tube of the electric tar catcher is the sedimentation electrode, which is connected to the positive electrode of the current, and the corona wire is the corona electrode, which is connected to the negative electrode of the power supply. When a high-voltage direct current is introduced, a non-uniform electric field is formed between the two electrodes. The corona phenomenon occurs around the corona electrode, and the gas near the corona electrode undergoes impact ionization. The gas molecules in the corona zone can carry positive and negative ions, while the gas outside the corona zone is filled with negatively charged ions, which attach to the tar droplets in the gas, causing the tar mist particles to move towards the inner wall of the sedimentation tube. On the sedimentation wall, they descend along the wall to the bottom of the electric tar catcher by gravity. Since the sedimentation electrode is grounded, electrons are introduced into the ground, and the gas ions become neutral molecules again. The top of the device leaves the electrostatic tar precipitator.
脫硫工段(HPF脫硫法)
Desulfurization section (HPF desulfurization method)
為什么要脫除煤氣中的硫?
Why remove sulfur from coal gas?
煤氣中硫的含量一般隨煉焦煤中的含硫量而變,煤氣中90%的硫以H2S形式存在,一般波動在4~10g/m3(煤氣)。煉焦煤中含硫質(zhì)量含量達1%,相當于煤氣中H2S含量為10g/m3。HCN含量取決于煤中氮含量和炭化溫度,一般為1~2.5g/m3(煤氣)。H2S和HCN都是有毒化合物,H2S吸入人體后,輕則中毒,重則致人死亡。生產(chǎn)車間允許的H2S含量小于10g/m3。HCN毒性更大,人吸入50mg即可死亡。生產(chǎn)車間允許的HCN含量小于0.3mg/m3。H2S和HCN的水溶液也具有強烈的毒性,水中含HCN達0.04~0.1mg/kg可致魚死亡。工廠排污水要求H2S和HCN的含量小于0.05mg/L。在煤氣輸送過程中會腐蝕設(shè)備和管道;作燃料燃燒時,生成SOx和NOx嚴重污染大氣,甚至形成酸雨。焦爐煤氣用在冶煉優(yōu)質(zhì)鋼和供化學(xué)合成工業(yè)時,對H2S含量的要求更加嚴格,有的甚至要求小于1mg/m3。
The sulfur content in coal gas generally varies with the sulfur content in coking coal. 90% of the sulfur in coal gas exists in the form of H2S, which generally fluctuates between 4-10g/m3 (coal gas). The sulfur content in coking coal reaches 1%, which is equivalent to a H2S content of 10g/m3 in coal gas. The HCN content depends on the nitrogen content and carbonization temperature in coal, generally ranging from 1 to 2.5 g/m3 (coal gas). H2S and HCN are both toxic compounds. When H2S is inhaled into the human body, it can cause mild poisoning and severe death. The allowable H2S content in the production workshop is less than 10g/m3. HCN is more toxic, and humans can die by inhaling 50mg. The allowable HCN content in the production workshop is less than 0.3mg/m3. The aqueous solution of H2S and HCN also has strong toxicity, and the presence of HCN in water up to 0.04-0.1mg/kg can cause fish death. The factory requires the content of H2S and HCN in the wastewater to be less than 0.05mg/L. Corrosion of equipment and pipelines during gas transportation; When burned as fuel, SOx and NOx are generated, which seriously pollute the atmosphere and even form acid rain. When coke oven gas is used for smelting high-quality steel and supplying chemical synthesis industry, the requirements for H2S content are more stringent, and some even require less than 1mg/m3.
綜上所述,焦爐煤氣必須脫除H2S和HCN。另外還可以變廢為寶,生產(chǎn)硫磺和硫酸等化工產(chǎn)品。
In summary, coke oven gas must remove H2S and HCN. In addition, it can also turn waste into treasure by producing chemical products such as sulfur and sulfuric acid.
1. 工藝流程
1. Process flow
脫硫裝置是以煤氣中的氨為堿源,HPF為催化劑的濕式氧化法脫硫工藝,再生為噴射再生方式。噴射再生槽設(shè)在脫硫塔上部。使用負壓脫硫工藝。
The desulfurization device is a wet oxidation desulfurization process using ammonia in coal gas as the alkali source and HPF as the catalyst, with regeneration using jet regeneration. The jet regeneration tank is located at the upper part of the desulfurization tower. Use negative pressure desulfurization process.
為保證脫硫后煤氣含H2S≤20mg/m3,脫硫裝置采用HPF為催化劑的三塔串聯(lián)設(shè)計。
To ensure that the H2S content in the desulfurized gas is ≤ 20mg/m3, the desulfurization unit adopts a three tower series design with HPF as the catalyst.
由鼓冷裝置電捕來的煤氣依次進入三個脫硫再生塔脫硫段。脫硫段頂噴淋下來的脫硫液逆流接觸煤氣以吸收煤氣中的硫化氫(同時吸收煤氣中的氨,以補充脫硫液中的堿源)。脫硫后煤氣含硫化氫約20mg/m3,送入鼓風(fēng)機室升壓。
The gas captured by the drum cooling device enters the desulfurization sections of three desulfurization regeneration towers in sequence. The desulfurization solution sprayed from the top of the desulfurization section contacts the gas in reverse flow to absorb hydrogen sulfide in the gas (while absorbing ammonia in the gas to supplement the alkali source in the desulfurization solution). After desulfurization, the gas contains about 20mg/m3 of hydrogen sulfide and is sent to the blower room for boosting.
在脫硫再生塔脫硫段內(nèi)吸收了H2S、HCN的脫硫液匯聚到塔底,然后用脫硫液泵送入脫硫再生塔頂部的再生段,通過再生段噴射器吸入空氣使溶液在塔內(nèi)得以氧化再生。再生后的溶液從塔頂經(jīng)液位調(diào)節(jié)器自流回脫硫再生塔脫硫段,吸收煤氣中的H2S、HCN。
The desulfurization solution that absorbs H2S and HCN in the desulfurization section of the desulfurization regeneration tower gathers at the bottom of the tower, and is then pumped into the regeneration section at the top of the desulfurization regeneration tower by the desulfurization solution pump. Air is sucked in through the regeneration section injector to oxidize and regenerate the solution inside the tower. The regenerated solution flows back to the desulfurization section of the desulfurization regeneration tower through the liquid level regulator at the top of the tower, absorbing H2S and HCN from the gas.
浮于脫硫再生塔頂部的硫磺泡沫,利用位差自流入泡沫槽,經(jīng)硫泡沫泵送入超級離心機,超級離心機為逆流臥式螺旋卸料沉降離心機,轉(zhuǎn)鼓轉(zhuǎn)速3000rpm。分離出的硫餅含水≤35%,集于硫池中,定期收集外賣。濾液收入濾液槽,大部分濾液經(jīng)濾液泵返回脫硫系統(tǒng),為防止HPF脫硫裝置NH4SCN、(NH4)2S2O3鹽類積累,一部分濾液送往提鹽單元提取鹽類。
The sulfur foam floating on the top of the desulfurization regeneration tower flows into the foam tank automatically by potential difference and is pumped into the super centrifuge by the sulfur foam pump. The super centrifuge is a countercurrent horizontal spiral discharge sedimentation centrifuge, and the rotating speed of the drum is 3000 rpm. The separated sulfur cake has a water content of ≤ 35% and is collected in a sulfur pool for regular takeout collection. The filtrate is collected into the filtrate tank, and most of the filtrate is returned to the desulfurization system through the filtrate pump. To prevent the accumulation of NH4SCN and (NH4) 2S2O3 salts in the HPF desulfurization unit, a portion of the filtrate is sent to the salt extraction unit for salt extraction.
提鹽單元為間歇操作,操作一釜為8小時。濾液由濾液原料槽抽入硫代硫酸氨蒸發(fā)器,用蒸汽加熱濃縮。為防止溫度過高,鹽類分解,蒸發(fā)需在真空條件下進行,控制蒸發(fā)溫度為90℃。待蒸發(fā)結(jié)束后,通過可旋轉(zhuǎn)的溜槽將料液放至真空過濾器,熱過濾出去(NH4)2CO3等雜質(zhì)。濾渣在容渣槽內(nèi)用濾液溶解后回脫硫系統(tǒng)。濾液至硫代硫酸氨結(jié)晶槽用夾套冷卻水(低溫水)冷至20℃左右,加入同種晶種使其結(jié)晶,最后在離心機中分離得到粗制硫代硫酸氨,用人工鏟出,裝入塑料袋作為產(chǎn)品出廠。
The salt extraction unit is operated intermittently, with one kettle operating for 8 hours. The filtrate is drawn from the filtrate raw material tank into the ammonium thiosulfate evaporator and concentrated by steam heating. To prevent excessive temperature and salt decomposition, evaporation needs to be carried out under vacuum conditions, and the evaporation temperature should be controlled at 90 ℃. After the evaporation is completed, the material liquid is placed into a vacuum filter through a rotatable chute, and impurities such as (NH4) 2CO3 are hot filtered out. The filter residue is dissolved in the filtrate in the slag tank and returned to the desulfurization system. The filtrate is cooled to around 20 ℃ in the ammonium thiosulfate crystallization tank using jacket cooling water (low-temperature water), and the same type of crystal seeds are added to crystallize it. Finally, crude ammonium thiosulfate is separated in a centrifuge and manually scooped out. The product is then placed in a plastic bag and shipped from the factory.
離心硫代硫酸氨后的濾液經(jīng)中間槽壓入硫氰酸氨原料槽,由此抽入硫氰酸氨蒸發(fā)器,用蒸汽加熱濃縮,待蒸發(fā)結(jié)束后,通過可旋轉(zhuǎn)的溜槽將料液放至真空過濾器,進一步除去(NH4)2CO3等雜質(zhì)。濾渣在容渣槽內(nèi)用濾液溶解后回脫硫系統(tǒng)。濾液至硫氰酸氨結(jié)晶槽用夾套冷卻水(低溫水)冷至30℃左右,加入同種晶種使其結(jié)晶,最后在離心機中分離得到粗制硫氰酸氨,用人工鏟出,裝入塑料袋作為產(chǎn)品出廠。離心濾液可回蒸發(fā)器循環(huán)套用。多次套用后,由于雜質(zhì)逐漸積累,需定期送回脫硫液系統(tǒng)。
After centrifuging ammonium thiosulfate, the filtrate is pressed into the ammonium thiocyanate raw material tank through an intermediate tank, and then drawn into the ammonium thiocyanate evaporator for concentration by steam heating. After the evaporation is complete, the material liquid is placed into a vacuum filter through a rotatable chute to further remove impurities such as (NH4) 2CO3. The filter residue is dissolved in the filtrate in the slag tank and returned to the desulfurization system. The filtrate is cooled to around 30 ℃ in the ammonium thiocyanate crystallization tank using jacket cooling water (low-temperature water), and the same type of crystal seeds are added to crystallize it. Finally, crude ammonium thiocyanate is separated in a centrifuge and manually scooped out. The product is then placed in a plastic bag and shipped from the factory. The centrifugal filtrate can be recycled back to the evaporator for reuse. After multiple applications, due to the gradual accumulation of impurities, it is necessary to regularly return the desulfurization solution system.
從蒸發(fā)器蒸出的水汽進入蒸汽冷凝器,除水后,進入排氣洗凈塔與來自蒸氨裝置的蒸氨廢水逆流接觸凈化,不凝性氣體經(jīng)真空泵直排大氣。
The water vapor evaporated from the evaporator enters the steam condenser, after removing water, it enters the exhaust cleaning tower and is purified by countercurrent contact with the ammonia wastewater from the ammonia distillation unit. Non condensable gases are directly discharged into the atmosphere through a vacuum pump.
經(jīng)蒸汽冷凝器冷凝后的廢水滿流至液封槽,送回脫硫液系統(tǒng)。
The wastewater condensed by the steam condenser flows to the liquid seal tank and is sent back to the desulfurization liquid system.
2. 工藝特點
2. Process characteristics
1)采用以氨為堿源,HPF為催化劑的焦爐煤氣脫硫脫氰新工藝,此法不但具有較高的脫硫脫氰效率,而且流程短,不需外加堿,催化劑用量少,操作費用低,一次性投資省。
1) A new process for desulfurization and decyanation of coke oven gas using ammonia as the base source and HPF as the catalyst is adopted. This method not only has high desulfurization and decyanation efficiency, but also has a short process, does not require additional alkali, requires less catalyst, has low operating costs, and saves one-time investment.
2)提鹽工藝成熟可靠,技術(shù)先進,生產(chǎn)操作穩(wěn)定,減少廢液排放量,實現(xiàn)了變廢為寶。
2) The salt extraction process is mature and reliable, with advanced technology, stable production operations, and reduced waste liquid emissions, achieving the goal of turning waste into treasure.
3. 主要技術(shù)操作指標
3. Main technical operation indicators
脫硫塔前煤氣溫度25~30℃
Gas temperature in front of desulfurization tower 25-30 ℃
脫硫塔后煤氣溫度30~35℃
Gas temperature after desulfurization tower is 30-35 ℃
脫硫再生塔底部脫硫液溫度~35℃
Bottom desulfurization solution temperature of desulfurization regeneration tower~35 ℃
主要技術(shù)操作指標泡沫槽溫度~35℃
Main technical operation index foam tank temperature~35 ℃
蒸發(fā)器溫度~90℃
Evaporator temperature~90 ℃
硫代硫酸氨結(jié)晶槽溫度~20℃
Temperature of ammonium thiosulfate crystallization tank~20 ℃
硫氰酸氨結(jié)晶槽溫度~30℃
Temperature of ammonium thiocyanate crystallization tank~30 ℃
單臺脫硫塔阻力1.5kPa
Resistance of a single desulfurization tower is 1.5kPa
真空泵前壓力-30kPa
Front pressure of vacuum pump -30kPa
脫硫液組成:
Composition of desulfurization solution:
H.P.F含量0.1~0.2g/l
H. P.F content 0.1-0.2g/l
游離氨含量4~5g/l
Free ammonia content 4-5g/l
PH值8.3~8.5 g/l
PH value 8.3-8.5 g/l
懸浮硫含量1~1.2g/l
Suspended sulfur content 1-1.2g/l
脫硫后煤氣含H2S≤20mg/m3
After desulfurization, the gas contains H2S ≤ 20mg/m3
4. 主要設(shè)備的工作原理
4. Working principle of main equipment
脫硫塔
desulfurization tower
自電捕焦油器出來的焦爐煤氣進入第一級脫硫再生塔的脫硫段下部,并沿脫硫段自下而上與頂部噴灑的脫硫液逆流接觸,將煤氣中的大部分H2S吸收在脫硫液中。吸收了H2S后的脫硫液通過塔底由脫硫液循環(huán)泵泵至脫硫再生塔頂,通過噴射器與空氣接觸,進行氧化再生,再生的溶液經(jīng)液位調(diào)節(jié)器自流到脫硫段頂部與煤氣逆流接觸,循環(huán)使用。從一級脫硫系統(tǒng)凈化后的焦爐煤氣依次進入第二級、第三級脫硫再生塔,其過程與一級脫硫相同。經(jīng)過三級脫硫,煤氣中的H2S含量可達到20mg/m3以下。
The coke oven gas from the electrostatic tar precipitator enters the lower part of the desulfurization section of the first stage desulfurization regeneration tower and comes into contact with the top sprayed desulfurization solution from bottom to top in reverse flow along the desulfurization section, absorbing most of the H2S in the gas into the desulfurization solution. After absorbing H2S, the desulfurization solution is pumped by the desulfurization solution circulation pump from the bottom of the tower to the top of the desulfurization regeneration tower. It is then subjected to oxidation regeneration by contact with air through an injector. The regenerated solution flows automatically to the top of the desulfurization section through a liquid level regulator and comes into contact with the gas in reverse flow, for recycling. The purified coke oven gas from the first stage desulfurization system enters the second and third stage desulfurization regeneration towers in sequence, following the same process as the first stage desulfurization. After three-stage desulfurization, the H2S content in the gas can reach below 20mg/m3.
為了保持一定的催化劑濃度并盡量減少其耗量,采用了連續(xù)補加少量催化劑的設(shè)施。
In order to maintain a certain concentration of catalyst and minimize its consumption, a facility of continuously adding a small amount of catalyst was adopted.
為了保證脫硫效果,采用向脫硫塔連續(xù)補充濃氨水。采用引射自吸式再生,硫泡沫自流入硫泡沫槽然后硫泡沫加工成硫磺或硫膏,再生后的脫硫液經(jīng)液位調(diào)節(jié)器后自動流入脫硫段進行煤氣脫硫生產(chǎn),經(jīng)自吸噴射器空氣與脫硫液充分混合,發(fā)生氧化、再生反應(yīng).
To ensure the desulfurization effect, continuous supply of concentrated ammonia water is used to the desulfurization tower. The injection self-priming regeneration is adopted. The sulfur foam flows into the sulfur foam tank automatically, and then the sulfur foam is processed into sulfur or sulfur paste. The regenerated desulfurization liquid flows into the desulfurization section automatically after passing through the liquid level regulator for gas desulfurization production. The air of the self-priming injector is fully mixed with the desulfurization liquid, and oxidation and regeneration reactions occur
5. 主要環(huán)保措施
5. Main environmental protection measures
1) 各貯槽放散氣體經(jīng)壓力平衡系統(tǒng)回吸煤氣管道,廢氣不外排。
1) The gas released from each storage tank is sucked back into the gas pipeline through the pressure balance system, and the exhaust gas is not discharged outside.
2) 放空液進入地下放空槽,然后返回系統(tǒng),不外排。
2) The emptying liquid enters the underground emptying tank and then returns to the system without being discharged externally.
3) 利用提鹽工藝減少廢液排放量,實現(xiàn)了變廢為寶。
3) By utilizing the salt extraction process, the discharge of waste liquid has been reduced, achieving the goal of turning waste into treasure.
6、主要影響因素
6. Main influencing factors
脫硫塔的操作溫度和壓力:溫度過高或壓力過大會加速副反應(yīng)的進行。
The operating temperature and pressure of the desulfurization tower: If the temperature or pressure is too high, it will accelerate the progress of side reactions.
脫硫液的pH值:脫硫液的pH值應(yīng)維持在8.1~8.7之間,小于8.1反應(yīng)慢,大于8.7副反應(yīng)加劇。
The pH value of desulfurization solution: The pH value of desulfurization solution should be maintained between 8.1 and 8.7. If it is less than 8.1, the reaction will be slow, and if it is greater than 8.7, the side reactions will intensify.
還有,再生時間和脫硫劑用量等因素。
Also, factors such as regeneration time and desulfurizer dosage.
硫銨工段(噴淋式飽和器生產(chǎn)硫銨)
Ammonium sulfate section (spray saturator production of ammonium sulfate)
為什么要對煤氣進行脫氨?
Why do we need to deamination coal gas?
煤熱解溫度高于500℃時形成氨,高溫?zé)捊姑簹庵械牡s有20~25%轉(zhuǎn)化為氨,粗煤氣中氨含量為8~11g/m3(體積百分數(shù)1.0~1.5%)煤氣中氨含量的8~16%在煤氣冷卻中溶于凝縮液中。殘留于煤氣中的氨大部分被終冷水吸收,在涼水塔噴灑冷卻時又都解吸進入到大氣,造成污染;由于煤氣中的氨與氰化氫化合,形成溶解度高的復(fù)合物,從而加劇了腐蝕作用。
When the coal pyrolysis temperature is higher than 500 ℃, ammonia is formed. About 20-25% of the nitrogen in high-temperature coking gas is converted into ammonia. The ammonia content in crude gas is 8-11g/m3 (volume percentage 1.0-1.5%). 8-16% of the ammonia content in gas dissolves in the condensate during gas cooling. Most of the ammonia remaining in the gas is absorbed by the final cooling water, and when it is sprayed and cooled in the cooling tower, it is desorbed into the atmosphere, causing pollution; Due to the combination of ammonia and hydrogen cyanide in coal gas, a highly soluble complex is formed, which exacerbates the corrosion effect.
此外,煤氣中的氨在燃燒時會生成有毒的、有腐蝕性的氧化氮;氨在粗苯回收中能使油和水形成穩(wěn)定的乳化液,妨礙油水分離。上述這些都使現(xiàn)代化焦化生產(chǎn)遇到困難,為此,煤氣中氨含量不允許超過0.03g/m3。
In addition, ammonia in coal gas generates toxic and corrosive nitrogen oxides during combustion; Ammonia can form a stable emulsion between oil and water in crude benzene recovery, which hinders oil-water separation. All of the above make modern coking production difficult. Therefore, the ammonia content in the gas is not allowed to exceed 0.03g/m3.
因此必須對煤氣中的氨加以回收,目前中國大部分焦化廠采用硫酸自煤氣中吸收氨,生產(chǎn)硫酸銨,作為化學(xué)肥料加以利用。
Therefore, it is necessary to recover ammonia from coal gas. Currently, most coking plants in China use sulfuric acid to absorb ammonia from coal gas, produce ammonium sulfate, and utilize it as a chemical fertilizer.
1. 工藝流程
1. Process flow
由煤氣鼓風(fēng)機送來的煤氣經(jīng)煤氣預(yù)熱器進入飽和器。煤氣在飽和器的上段分兩股入環(huán)形室經(jīng)循環(huán)母液噴灑,其中的氨被母液中的硫酸吸收,然后煤氣合并成一股進入后室經(jīng)母液最后一次噴淋進飽和器內(nèi)旋風(fēng)式除酸器,以便分離煤氣所夾帶的酸霧,最后送至終冷洗苯裝置。
The gas sent by the gas blower enters the saturator through the gas preheater. The gas is divided into two streams in the upper section of the saturator and sprayed into the annular chamber through the circulating mother liquor. The ammonia in the mother liquor is absorbed by the sulfuric acid in the mother liquor, and then the gas is combined into one stream and enters the rear chamber. The mother liquor is sprayed for the last time and enters the cyclone type acid remover in the saturator to separate the acid mist carried by the gas. Finally, it is sent to the final cold washing benzene unit.
飽和器下段上部的母液經(jīng)母液循環(huán)泵連續(xù)抽出送至環(huán)形室噴灑,吸收了氨的循環(huán)母液由中心下降管流至飽和器下段的底部,在此晶核通過飽和介質(zhì)向上運動,使晶體長大,并引起顆粒分級。用結(jié)晶泵將其底部的漿液送至結(jié)晶槽。飽和器滿流口溢出的母液經(jīng)滿流槽流至母液貯槽,滿流槽內(nèi)含液封槽,滿流槽底部的母液用小母液泵送入飽和器的后室噴淋。母液貯槽的母液用小母液泵送至滿流槽。此外,母液貯槽還可供飽和器檢修時貯存母液之用。
The mother liquor in the upper part of the lower section of the saturator is continuously pumped out by the mother liquor circulation pump and sent to the annular chamber for spraying. The circulating mother liquor that absorbs ammonia flows from the central downcomer to the bottom of the lower section of the saturator, where the crystal nuclei move upward through the saturated medium, causing crystal growth and particle classification. Use a crystallization pump to send the slurry at the bottom to the crystallization tank. The mother liquor overflowing from the full flow port of the saturator flows into the mother liquor storage tank through the full flow channel, which contains a liquid sealed tank. The mother liquor at the bottom of the full flow channel is pumped into the rear chamber of the saturator for spraying by a small mother liquor pump. The mother liquor from the mother liquor storage tank is pumped to the full flow tank using a small mother liquor pump. In addition, the mother liquor storage tank can also be used to store the mother liquor during the maintenance of the saturator.
結(jié)晶槽的漿液排放到離心機,經(jīng)分離的硫銨由輸送機送至振動流化床干燥機,并用被熱風(fēng)器加熱的空氣干燥,再經(jīng)冷風(fēng)冷卻后進入硫銨貯斗,然后稱量、包裝送入成品庫。
The slurry from the crystallization tank is discharged into a centrifuge, and the separated ammonium sulfate is transported by a conveyor to a vibrating fluidized bed dryer, where it is dried using air heated by a hot air blower. After being cooled by cold air, it enters the ammonium sulfate storage hopper, weighed, packaged, and sent to the finished product warehouse.
濾出的母液與結(jié)晶槽滿流出來的母液一同自流回飽和器的下段。
The filtered mother liquor flows back to the lower section of the saturator together with the mother liquor flowing out from the crystallization tank.
干燥硫銨后的尾氣在排入大氣前設(shè)有兩級除塵。首先經(jīng)兩組干式旋風(fēng)除塵器除去尾氣中夾帶的大部分粉塵,再由尾氣引風(fēng)機抽送至尾氣洗凈塔,用尾氣洗凈塔泵對尾氣進行連續(xù)循環(huán)噴灑,以進一步除去尾氣中夾帶的殘留粉塵,最后經(jīng)捕霧器除去尾氣中夾帶的液滴后排入大氣。
The tail gas after drying ammonium sulfate is equipped with two-stage dust removal before being discharged into the atmosphere. Firstly, most of the dust carried in the exhaust gas is removed by two sets of dry cyclone dust collectors. Then, the exhaust gas is drawn to the exhaust gas cleaning tower by the exhaust gas induced draft fan, and the exhaust gas is continuously circulated and sprayed by the exhaust gas cleaning tower pump to further remove the residual dust carried in the exhaust gas. Finally, the liquid droplets carried in the exhaust gas are removed by the mist collector and discharged into the atmosphere.
油庫來的硫酸送至硫酸高置槽,然后自流到滿流槽。
The sulfuric acid from the oil depot is sent to the sulfuric acid high-level tank, and then flows automatically to the full flow tank.
2. 工藝特點
2. Process characteristics
1)采用噴淋式飽和器,集酸洗、除酸、結(jié)晶為一體,設(shè)備體積小,脫氨效率高,硫銨顆粒大,流程簡單,工藝先進,技術(shù)可靠。
1) Adopting a spray type saturator, integrating acid washing, acid removal, and crystallization, the equipment has a small volume, high deamination efficiency, large ammonium sulfate particles, simple process, advanced technology, and reliable technology.
2)噴淋飽和器系統(tǒng)阻力小,鼓風(fēng)機能耗低。
2) The spray saturator system has low resistance and low energy consumption of the blower.
3)硫銨母液系統(tǒng)設(shè)備及管道均采用超低碳不銹鋼材質(zhì),使用壽命長,可保證裝置長期連續(xù)穩(wěn)定操作,減少維護費用。
3) The equipment and pipelines of the ammonium sulfate mother liquor system are made of ultra-low carbon stainless steel material, which has a long service life and can ensure long-term continuous and stable operation of the device, reducing maintenance costs.
4)硫銨干燥采用振動流化床,干燥效果好,易于操作維護。
4) Ammonium sulfate drying adopts a vibrating fluidized bed, which has good drying effect and is easy to operate and maintain.
5)干燥尾氣采用干式及濕式兩級除塵,除塵效率高,尾氣中無粉塵夾帶。
5) Dry exhaust gas adopts two-stage dust removal methods of dry and wet, with high dust removal efficiency and no dust entrainment in the exhaust gas.
3. 主要技術(shù)操作指標
3. Main technical operation indicators
飽和器后煤氣含氨≤0.05g/m3
Ammonia content in gas after saturator ≤ 0.05g/m3
飽和器后煤氣溫度~55℃
Gas temperature after saturator~55 ℃
干燥后硫銨含水≤0.3%
After drying, the moisture content of ammonium sulfate is ≤ 0.3%
飽和器的阻力≤2kPa
The resistance of the saturator is ≤ 2kPa
4. 主要環(huán)保措施
4. Main environmental protection measures
1)放空母液進入地下放空槽,然后返回系統(tǒng),不外排。
1) The emptying mother liquor enters the underground emptying tank and then returns to the system without being discharged.
2)硫銨干燥尾氣采用干式及濕式兩級除塵,無粉塵夾帶。
2) The tail gas of ammonium sulfate drying adopts two-stage dry and wet dust removal, without dust entrainment.
5.主要設(shè)備的工作原理
5. Working principle of main equipment
噴淋式飽和器
Spray saturator
煤氣經(jīng)電捕焦油、脫硫并經(jīng)鼓風(fēng)機增壓后進入煤氣預(yù)熱器,預(yù)熱到60~70℃,目的是蒸出飽和器中水分,防止母液稀釋。煤氣由飽和器的中央氣管經(jīng)泡沸傘穿過母液層鼓泡而出,其中的氨被硫酸吸收,形成硫酸銨。在出酸器中分離出攜帶的液滴后,去粗苯回收工段。飽和器后煤氣含氨量一般要求小于0.03g/m3。
The gas is subjected to electric tar capture, desulfurization, and pressurized by a blower before entering the gas preheater, which is preheated to 60-70 ℃ to evaporate the water in the saturator and prevent dilution of the mother liquor. Gas is bubbled out from the central gas pipe of the saturator through the mother liquor layer through a bubbling umbrella, and the ammonia in it is absorbed by sulfuric acid to form ammonium sulfate. After separating the carried droplets in the acid extractor, they are sent to the crude benzene recovery section. The ammonia content in the gas after saturator is generally required to be less than 0.03g/m3.
飽和器中母液經(jīng)水封管進入滿流槽,由此用泵打回到飽和器的底部,這樣構(gòu)成母液循環(huán)系統(tǒng),并在器內(nèi)形成上升的母液流。硫酸銨結(jié)晶沉于飽和器的錐底部,用泵把漿液送回到結(jié)晶槽,在此從漿液中沉淀出硫酸銨結(jié)晶,結(jié)晶槽滿流液又回到飽和器。
The mother liquor in the saturator enters the full flow channel through a water sealed pipe, and is pumped back to the bottom of the saturator, forming a mother liquor circulation system and an upward mother liquor flow inside the saturator. Ammonium sulfate crystals settle at the bottom of the saturator cone, and the slurry is pumped back to the crystallization tank, where ammonium sulfate crystals precipitate from the slurry. The crystallization tank is filled with liquid and returns to the saturator.
硫酸銨結(jié)晶漿液在離心機分出結(jié)晶,結(jié)晶含水分1%~2%,在干燥器中脫水后送去倉庫。
The ammonium sulfate crystallization slurry is separated into crystals in a centrifuge, with a moisture content of 1% to 2%. After dehydration in a dryer, it is sent to the warehouse.
6.主要影響因素
6. Main influencing factors
母液酸度:
Mother liquor acidity:
氨吸收設(shè)備內(nèi)母液的酸度,主要影響硫酸銨結(jié)晶的粒度。隨著母液酸度的提高,結(jié)晶平均粒度下降,另外,隨著酸度的提高,母液黏度增大,增加了硫酸銨分子的擴散阻力,阻礙了晶體正常的成長。
The acidity of the mother liquor in the ammonia absorption equipment mainly affects the particle size of ammonium sulfate crystals. As the acidity of the mother liquor increases, the average crystal size decreases. In addition, with the increase of acidity, the viscosity of the mother liquor increases, which increases the diffusion resistance of ammonium sulfate molecules and hinders the normal growth of crystals.
母液溫度:
Mother liquor temperature:
母液溫度影響晶體的生長速度。通常晶體的生長速度隨母液溫度的升高而增大,且由于晶體各棱面對平均生成速度比晶體沿長向生長速度增長較快,故提高溫度有助于降低長寬比而形成較好的晶體。但溫度也不宜過高,過高想成局部過飽和現(xiàn)象,促使大量晶核形成。一般母液溫度控制在50~55℃。
The temperature of the mother liquor affects the growth rate of crystals. The growth rate of crystals usually increases with the temperature of the mother liquid, and because the average generation rate of each facet of the crystal increases faster than the growth rate of the crystal along the longitudinal direction, increasing the temperature helps to reduce the aspect ratio and form better crystals. But the temperature should not be too high, as it may cause local supersaturation and promote the formation of a large number of crystal nuclei. The temperature of the mother liquor is generally controlled between 50-55 ℃.
母液循環(huán):
Mother liquor circulation:
母液循環(huán)循環(huán)的目的是使器內(nèi)的母液得到充分的攪拌,以提高傳質(zhì)速率。同時盡量使器內(nèi)的母液酸度和溫度均勻有利于晶核長大。
The purpose of mother liquor circulation is to thoroughly stir the mother liquor in the reactor to improve the mass transfer rate. At the same time, try to make the acidity and temperature of the mother liquor in the reactor uniform, which is beneficial for the growth of crystal nuclei.
另外,還有晶比和雜質(zhì)的影響:晶比是指懸浮于母液中硫酸銨結(jié)晶的體積對母液總體積的百分比。母液中的雜質(zhì)對晶體生長有抑制作用。
In addition, there are also effects of crystal ratio and impurities: crystal ratio refers to the percentage of the volume of ammonium sulfate crystals suspended in the mother liquor to the total volume of the mother liquor. Impurities in the mother liquor have an inhibitory effect on crystal growth.
終冷洗苯工段
Final cold washing benzene section
煤氣進入吸苯塔前為什么要進行最終冷卻?
Why is final cooling necessary before gas enters the benzene absorption tower?
粗苯回收主要影響因素之一就是回收溫度。煤氣中苯屬烴的含量一定時,如果洗油吸收苯的吸收溫度較低,吸收推動力增大,苯回收率增加。實踐證明,最適宜的溫度是20~28℃。但煤氣經(jīng)過飽和器后,溫度一般為50~65℃。為了有效地利用洗油吸收煤氣中的粗苯,必須進行煤氣的最終冷卻。
One of the main influencing factors for crude benzene recovery is the recovery temperature. When the content of benzene hydrocarbons in coal gas is constant, if the absorption temperature of benzene by wash oil is low, the absorption driving force increases, and the benzene recovery rate increases. Practice has proven that the most suitable temperature is 20-28 ℃. But after passing through the saturator, the temperature of the gas is generally 50-65 ℃. In order to effectively utilize wash oil to absorb crude benzene in coal gas, it is necessary to perform final cooling of the gas.
1、工藝流程
1. Process flow
從硫銨裝置來的約55℃的煤氣,首先進入終冷塔,煤氣分2段冷卻。下段用約37℃循環(huán)冷卻水,上段用約24℃循環(huán)冷卻水將煤氣冷到~25℃后進入洗苯塔,煤氣經(jīng)貧油洗滌脫除粗苯并經(jīng)捕霧后,送往用戶。
The gas at approximately 55 ℃ from the ammonium sulfate plant first enters the final cooling tower, where it is cooled in two stages. The lower section uses circulating cooling water at about 37 ℃, and the upper section uses circulating cooling water at about 24 ℃ to cool the gas to about 25 ℃ before entering the benzene washing tower. The gas is washed with lean oil to remove crude benzene and then sent to the user after mist capture.
終冷塔下段的循環(huán)冷卻水從塔中部進入終冷塔下段,與煤氣逆向接觸冷卻煤氣后用泵抽出,經(jīng)下段循環(huán)噴灑液冷卻器,用循環(huán)水冷卻到37℃進入終冷塔中部循環(huán)使用。終冷塔上段的循環(huán)冷卻水從塔頂部進入終冷塔上段冷卻煤氣后用泵抽出,經(jīng)上段循環(huán)噴灑液冷卻器,用低溫水冷卻到24℃進入終冷塔頂部循環(huán)使用。同時,在終冷塔上段加入一定量的堿液,進一步脫除煤氣中的H2S,保證煤氣中的H2S含量≤20mg/m3。下段排出的冷凝液送至酚氰廢水處理,上段排出的含堿冷凝液送至蒸氨裝置蒸氨塔頂,分解剩余氨水中的固定銨。
The circulating cooling water in the lower section of the final cooling tower enters the lower section of the final cooling tower from the middle of the tower, cools the gas in reverse contact with it, and is pumped out. It then passes through the circulating spray liquid cooler in the lower section and is cooled to 37 ℃ by circulating water before entering the middle section of the final cooling tower for circulation. The circulating cooling water in the upper section of the final cooling tower enters the cooling gas in the upper section of the final cooling tower from the top of the tower and is pumped out. After passing through the upper section circulating spray liquid cooler, it is cooled to 24 ℃ with low-temperature water and enters the top of the final cooling tower for circulation. At the same time, a certain amount of alkaline solution is added to the upper section of the final cooling tower to further remove H2S from the gas, ensuring that the H2S content in the gas is ≤ 20mg/m3. The condensate discharged from the lower section is sent to the phenol cyanide wastewater treatment, while the alkaline condensate discharged from the upper section is sent to the top of the ammonia distillation unit to decompose the fixed ammonium in the remaining ammonia water.
由粗苯蒸餾裝置送來的貧油從洗苯塔的頂部噴灑,與煤氣逆向接觸吸收煤氣中的苯,塔底富油經(jīng)富油泵送至粗苯蒸餾工段脫苯后循環(huán)使用。系統(tǒng)消耗的洗油,定期從洗油槽經(jīng)富油泵入口補入系統(tǒng)。
The lean oil sent from the crude benzene distillation unit is sprayed from the top of the benzene washing tower, which comes into reverse contact with the gas to absorb benzene in the gas. The rich oil at the bottom of the tower is pumped by the rich oil pump to the crude benzene distillation section for benzene removal and recycling. The wash oil consumed by the system is regularly replenished into the system through the rich oil pump inlet from the wash oil tank.
2、工藝特點
2. Process characteristics
1)終冷采用直冷空噴形式,基建投資少。
1) The final cooling adopts a direct cooling air spray form, which requires less infrastructure investment.
2)煤氣終冷采用閉路循環(huán)連續(xù)排污工藝,既減少污水排放量,又達到保護大氣環(huán)境的目的。
2) The gas final cooling adopts a closed-loop continuous sewage discharge process, which not only reduces the amount of sewage discharge, but also achieves the goal of protecting the atmospheric environment.
3、主要技術(shù)操作指標
3. Main technical operation indicators
出終冷塔的煤氣溫度25~27℃
The temperature of the gas exiting the final cooling tower is 25-27 ℃
進洗苯塔的貧油溫度27~29℃
The lean oil temperature entering the benzene washing tower is 27-29 ℃
終冷塔阻力<1.5kPa
Final cooling tower resistance < 1.5kPa
洗苯塔阻力<1.5kPa
The resistance of the benzene washing tower is less than 1.5kPa
洗苯塔后煤氣含苯量~4g/m3
The benzene content in the gas after washing the benzene tower is about 4g/m3
4、主要環(huán)保措施
4. Main environmental protection measures
系統(tǒng)內(nèi)的放空水、放空油集中回收進入地下放空槽,然后返回系統(tǒng),不外排。
The emptying water and oil in the system are collected and recycled into the underground emptying tank, and then returned to the system without being discharged.
5、主要設(shè)備的工作原理
5. Working principle of main equipment
終冷塔
Final cooling tower
終冷塔為隔板式塔分兩段,下段用從涼水塔來的循環(huán)水噴淋,將煤氣冷卻至40℃左右,上段用溫度為20~23℃的低溫循環(huán)水噴淋,將煤氣再冷卻至25℃左右。熱水叢終冷塔底部經(jīng)水封管流到熱水池,然后用泵送至涼水塔,經(jīng)制冷機冷卻后自流入冷水池,再用泵送到終冷塔下段。
The final cooling tower is a partition tower divided into two sections. The lower section is sprayed with circulating water from the cooling tower to cool the gas to around 40 ℃, while the upper section is sprayed with low-temperature circulating water at a temperature of 20-23 ℃ to further cool the gas to around 25 ℃. The bottom of the hot water bundle final cooling tower flows through a water seal pipe to the hot water tank, and then is pumped to the cooling tower. After being cooled by the refrigeration machine, it flows into the cold water tank and is then pumped to the lower section of the final cooling tower.
洗苯塔
Benzene washing tower
填料洗苯塔:填料分布在塔板上形成了煤氣的曲折通道,增加了煤氣的停留時間,同時增加了苯的吸收率。為了保證洗油在塔內(nèi)的截面上均勻分布,在塔內(nèi)每隔一定距離安裝一塊帶有煤氣渦流罩的液體再分布板。煤氣渦流罩按同心圓排列在液體再分布板上,彎管出口方向與圓周相切,在同一圓周上的出口方向一致,相鄰兩圓周上的方向相反。由于彎管的導(dǎo)向作用,煤氣流出渦流罩時,形成多股上升的旋風(fēng)氣流,因而使煤氣得到混合,以均一的濃度進入上段填料。匯集在液體再分布板上的洗油,經(jīng)升氣管內(nèi)的彎管流到設(shè)于升氣管中心的圓棒表面,再流到下端的齒形圓板上,借重力噴濺成液滴而淋灑到下段填料上。從而可消除洗油沿塔壁下流及分布不均的現(xiàn)象。
Packing benzene washing tower: The packing is distributed on the tray to form a tortuous channel for gas, increasing the residence time of gas and increasing the absorption rate of benzene. In order to ensure uniform distribution of wash oil on the cross-section inside the tower, a liquid redistribution plate with a gas vortex hood is installed at regular intervals inside the tower. The gas vortex hood is arranged in concentric circles on the liquid redistribution plate, with the outlet direction of the bent pipe tangent to the circumference. The outlet direction on the same circumference is consistent, while the directions on adjacent circumferences are opposite. Due to the guiding effect of the bent pipe, when the gas flows out of the vortex hood, multiple upward swirling airflows are formed, which mix the gas and enter the upper packing at a uniform concentration. The wash oil collected on the liquid redistribution plate flows through the curved pipe in the riser to the surface of the circular rod located at the center of the riser, and then flows onto the toothed circular plate at the lower end, where it splashes into droplets by gravity and drips onto the lower filling material. This can eliminate the phenomenon of washing oil flowing down and unevenly distributed along the tower wall.
6、洗苯的主要影響因素
6. The main influencing factors of benzene washing
吸收溫度:
Absorption temperature:
當煤氣中苯族烴的含量一定時,溫度愈低,洗油中與其平衡的粗苯含量愈高。
When the content of benzene hydrocarbons in coal gas is constant, the lower the temperature, the higher the content of crude benzene in the wash oil that is in equilibrium with it.
洗油的吸收能力及循環(huán)油量:
Absorption capacity and circulating oil volume of wash oil:
在其他條件一定時,洗油的相對分子質(zhì)量減小將使洗油中粗苯含量增大,即吸收能力提高。增加洗油循環(huán)量可降低洗油中粗苯的含量,增加吸收推動力,從而可提高粗苯回收率。
When other conditions are constant, a decrease in the relative molecular weight of the wash oil will increase the content of crude benzene in the wash oil, that is, the absorption capacity will be improved. Increasing the circulation of wash oil can reduce the content of crude benzene in the wash oil, increase the absorption driving force, and thus improve the recovery rate of crude benzene.
貧油含苯量:
Poor oil benzene content:
貧油含苯量是決定塔后煤氣含苯族烴量的主要因素之一。此外還有,如吸收表面積、煤氣壓力和流速等影響因素。
The benzene content in lean oil is one of the main factors determining the benzene hydrocarbon content in the gas after the tower. In addition, there are influencing factors such as absorption surface area, gas pressure, and flow rate.
7、洗油的質(zhì)量要求
7. Quality requirements for washing oil
為滿足從煤氣中回收和制取粗苯的要求,洗油應(yīng)具備如下性能:
To meet the requirements for recovering and producing crude benzene from coal gas, wash oil should have the following properties:
1)常溫下對苯族烴有良好的吸收能力,在加熱時又能使苯族烴很好地分離出來;
1) At room temperature, it has good absorption capacity for benzene hydrocarbons, and when heated, it can effectively separate benzene hydrocarbons;
2)具有化學(xué)穩(wěn)定性,記在長期使用中吸收能力基本穩(wěn)定;
2) Has chemical stability and has a stable absorption capacity over long-term use;
3)在吸收操作溫度下不應(yīng)析出固體沉淀物;
3) Solid precipitates should not precipitate at the absorption operating temperature;
4)易與水分離,且不生成乳化物;
4) Easy to separate from water and does not generate emulsions;
5)有較好的流動性,已于用泵抽送并能在填料上均勻分布。
5) Has good fluidity, can be pumped and evenly distributed on the packing.
焦化廠用于吸苯的主要焦油洗油和石油洗油。
The main tar wash oil and petroleum wash oil used for benzene absorption in coking plants.
焦油洗油是高溫煤焦油中230~300℃的餾分,要求萘含量小于13%,焦油中含有一定數(shù)量的萘,有助于降低從洗油中析出沉淀物的溫度。
Tar wash oil is a fraction of high-temperature coal tar at 230-300 ℃, with a naphthalene content of less than 13%. Tar contains a certain amount of naphthalene, which helps to reduce the temperature at which precipitates precipitate from the wash oil.
石油洗油系指輕柴油,為石油精餾時,在餾出汽油和煤油后所切取的餾分。(270~350℃的餾分,C9~C14)生產(chǎn)實踐表明:用石油洗油苯,具有洗油耗量低、油水分離容易記憶操作等優(yōu)點。石油洗油脫萘能力強,洗苯能力弱,故循環(huán)量大,蒸汽耗量也大。
Petroleum wash oil refers to light diesel oil, which is a fraction obtained by distilling gasoline and kerosene during petroleum distillation. The production practice of (270-350 ℃ fraction, C9-C14) shows that using petroleum to wash benzene oil has the advantages of low washing oil consumption and easy memory operation for oil-water separation. Petroleum washing has strong naphthalene removal ability and weak benzene washing ability, resulting in a large circulation volume and high steam consumption.
蒸氨裝置
Ammonia evaporation device
1、工藝流程
1. Process flow
剩余氨水處理量按30 m3/h設(shè)計。
The remaining ammonia water treatment capacity is designed at 30 m3/h.
剩余氨水與蒸氨塔底排出的蒸氨廢水換熱后進入蒸氨塔,蒸氨塔底的一部分蒸氨廢水經(jīng)蒸汽再沸器用蒸汽加熱后流回蒸氨塔并閃蒸產(chǎn)生蒸汽。塔頂同時加入從終冷塔上段排出的含堿冷凝液以分解剩余氨水中固定氨。蒸氨塔頂部的氨汽經(jīng)分縮器和氨汽冷凝冷卻器冷凝冷卻后變成濃氨水,進入脫硫裝置脫硫再生塔。換熱后的蒸氨廢水進入廢水冷卻器冷卻后送至酚氰廢水處理站。
The remaining ammonia water exchanges heat with the ammonia distillation wastewater discharged from the bottom of the ammonia distillation tower and enters the ammonia distillation tower. A portion of the ammonia distillation wastewater at the bottom of the ammonia distillation tower is heated with steam by a steam reboiler and flows back to the ammonia distillation tower to flash produce steam. Simultaneously add alkaline condensate discharged from the upper section of the final cooling tower to the top of the tower to decompose the remaining ammonia water and fix ammonia. The ammonia vapor at the top of the ammonia distillation tower is condensed and cooled by the condenser and ammonia vapor condenser to become concentrated ammonia water, which enters the desulfurization regeneration tower of the desulfurization unit. After heat exchange, the steam ammonia wastewater enters the wastewater cooler for cooling and is sent to the phenol cyanide wastewater treatment station.
2、工藝特點
2. Process characteristics
1)蒸氨塔采用不銹鋼浮閥塔,操作穩(wěn)定,蒸餾效率高,使用年限長。
1) The ammonia distillation tower adopts a stainless steel float valve tower, which has stable operation, high distillation efficiency, and long service life.
2)蒸氨塔分縮器采用鈦材質(zhì),耐腐蝕。
2) The ammonia distillation tower condenser is made of titanium material, which is corrosion-resistant.
3、主要技術(shù)操作指標
3. Main technical operation indicators
蒸氨塔頂溫度96℃
Ammonia distillation tower top temperature 96 ℃
蒸氨塔底壓力0.03~0.04MPa
Bottom pressure of ammonia distillation tower 0.03-0.04MPa
廢水冷卻器后蒸氨廢水的溫度40℃
The temperature of the ammonia wastewater after the wastewater cooler is 40 ℃
4、主要設(shè)備的工作原理
4. Working principle of main equipment
蒸氨塔:
Ammonia distillation tower:
剩余氨水由塔上部第三板加入,沿各層塔板流下來的氨水與從塔底層送入的直接汽相接觸。水蒸氣經(jīng)泡罩齒隙沸騰穿越塔板上的氨水層,形成鼓泡現(xiàn)象。在塔板上氨水與蒸汽相遇被加熱至沸點,水中的氨、二氧化碳、硫化氫等隨氣體上升逐步轉(zhuǎn)入氣體中,這樣的過程一直進行到塔底為止,最后由塔底排出的廢水含氨量小于0.1g/L時,。當剩余氨水為混合氨水,入塔溫度為60~70℃時,則每立方米氨水的直接蒸汽耗量為200Kg左右。
The remaining ammonia water is added from the third plate at the top of the tower, and the ammonia water flowing down along each layer of the tower plate comes into contact with the direct vapor phase sent from the bottom of the tower. Water vapor boils through the gaps between the bubble hood teeth and passes through the ammonia layer on the tray, forming a bubbling phenomenon. On the tray, ammonia water meets steam and is heated to boiling point. Ammonia, carbon dioxide, hydrogen sulfide, and other substances in the water gradually enter the gas as it rises. This process continues until the bottom of the tower, and finally when the ammonia content in the wastewater discharged from the bottom of the tower is less than 0.1g/L,. When the remaining ammonia water is mixed ammonia water and the inlet temperature is 60-70 ℃, the direct steam consumption per cubic meter of ammonia water is about 200kg.
氨分縮器
Ammonia separator
由蒸氨塔逸出的氣體混合物中的硫化氫、氰化物等對普通鋼管具有強烈的腐蝕作用,故目前多采用鑄鐵管埋入式分縮器。在分縮器中氨氣走管內(nèi),冷卻水走管外。此種分縮器耐酸性較好,使用壽命較長,但較笨重。
The hydrogen sulfide, cyanide, and other substances in the gas mixture released from the ammonia distillation tower have a strong corrosive effect on ordinary steel pipes, so cast iron pipe buried type reducers are currently commonly used. In the splitter, ammonia gas flows through the tube and cooling water flows through the tube. This type of splitter has good acid resistance and a long service life, but it is relatively bulky.
5、主要環(huán)保措施
5. Main environmental protection measures
放空液進入地下放空槽,然后返回系統(tǒng),不外排。
The emptying liquid enters the underground emptying tank and then returns to the system without being discharged externally.
粗苯蒸餾工段
Crude benzene distillation section
為什么要對粗苯進行回收?
Why recycle crude benzene?
粗苯是多種碳氫化合物組成的復(fù)雜混合物。粗苯本身用途不大。但由粗苯精制出的苯、甲苯、二甲苯、三甲苯等組分,是生產(chǎn)黃色炸藥、塑料等的重要原料。此外還含有不飽和化合物、硫化物、飽和烴、酚類和砒啶堿類。粗苯的產(chǎn)率一般為干基配合煤料的0.75%~1.1%,因此從炭化室逸出的煤氣含粗苯為28~35g/m3。
Crude benzene is a complex mixture composed of multiple hydrocarbons. Crude benzene itself has little practical use. But the components such as benzene, toluene, xylene, and trimethylbenzene refined from crude benzene are important raw materials for the production of yellow explosives, plastics, etc. In addition, it also contains unsaturated compounds, sulfides, saturated hydrocarbons, phenols, and arsenic bases. The yield of crude benzene is generally 0.75% to 1.1% of the dry coal feed, so the gas escaping from the carbonization chamber contains 28~35g/m3 of crude benzene.
粗苯的各主要組分均在180℃前餾出,180℃后的餾出物成為溶劑油。在測定粗苯中的各組分的含量和計算產(chǎn)量時,通常將180℃前餾出餾出量當作100%來計算,故以其180℃前餾出餾出量作為鑒別粗苯質(zhì)量的指標之一。粗苯在180℃前餾出餾出量取決于粗苯工段的工藝流程和操作制度。180℃前餾出餾出量愈多,粗苯質(zhì)量愈好。一般要求粗苯在180℃前餾出餾出量為93%~95%。
The main components of crude benzene are distilled before 180 ℃, and the distillate after 180 ℃ becomes solvent oil. When determining the content of each component in crude benzene and calculating the yield, the distillation yield before 180 ℃ is usually calculated as 100%. Therefore, the distillation yield before 180 ℃ is used as one of the indicators to identify the quality of crude benzene. The amount of crude benzene distilled before 180 ℃ depends on the process flow and operating system of the crude benzene section. The more distillate is produced before 180 ℃, the better the quality of crude benzene. Generally, it is required that the crude benzene be distilled off at 93% to 95% before 180 ℃.
1、工藝流程
1. Process flow
從終冷洗苯裝置送來的富油依次送經(jīng)油汽換熱器、貧富油換熱器,再經(jīng)管式爐加熱至190℃后進入脫苯塔,在此用再生器來的直接蒸汽進行汽提和蒸餾。塔頂逸出的粗苯蒸汽經(jīng)油汽換熱器、粗苯冷凝冷卻器后,進入油水分離器。分出的粗苯送入粗苯回流槽,部分用粗苯回流泵送至塔頂作為回流,其余進入粗苯中間槽,再用粗苯產(chǎn)品泵送至油庫。
The rich oil sent from the final cold washing benzene unit is sequentially sent through the oil steam heat exchanger, the rich and poor oil heat exchanger, and then heated to 190 ℃ in the tube furnace before entering the benzene removal tower, where direct steam from the regenerator is used for stripping and distillation. The crude benzene vapor escaping from the top of the tower enters the oil-water separator after passing through the oil vapor heat exchanger and crude benzene condenser. The separated crude benzene is sent to the crude benzene reflux tank, some of which are pumped to the top of the tower as reflux by the crude benzene reflux pump, while the rest enter the crude benzene intermediate tank and are then pumped to the oil depot by the crude benzene product pump.
脫苯塔底貧油槽排出的貧油,用熱貧油泵經(jīng)貧富油換熱器和一、二段貧油冷卻器冷卻至27~29℃后去終冷洗苯裝置。
The lean oil discharged from the bottom lean oil tank of the benzene removal tower is cooled to 27-29 ℃ by a hot lean oil pump through a lean rich oil heat exchanger and first and second stage lean oil coolers before being sent to the final cold washing benzene unit.
在脫苯塔的頂部設(shè)有斷塔盤及塔外油水分離器,以引出塔頂積水,穩(wěn)定操作。
At the top of the benzene removal tower, there is a broken tray and an external oil-water separator to remove the accumulated water at the top of the tower and ensure stable operation.
在脫苯塔側(cè)線引出萘油餾份,以降低貧油含萘。引出的萘油餾份進入殘渣槽。
Extract naphthalene oil fraction from the side line of the benzene removal tower to reduce the naphthalene content in lean oil. The extracted naphthalene oil fraction enters the residue tank.
為保證洗油質(zhì)量,從熱貧油泵來的貧油引出1~1.5%的富油,送入再生塔內(nèi),用經(jīng)管式爐過熱的蒸汽蒸吹再生。再生殘渣排入殘渣槽,用泵送至油庫裝置。
To ensure the quality of the washing oil, 1-1.5% of the rich oil is extracted from the lean oil pump and sent into the regeneration tower for regeneration using superheated steam from a tube furnace. The regenerated residue is discharged into the residue tank and pumped to the oil storage facility.
各油水分離器排出的分離水,經(jīng)控制分離器排入分離水槽,用泵送往冷凝鼓風(fēng)裝置剩余氨水槽。
The separated water discharged from each oil-water separator is controlled to be discharged into the separation water tank and pumped to the remaining ammonia water tank of the condensing blower device.
各貯槽的不凝氣集中引至吸煤氣管道。
The non condensable gas from each storage tank is concentrated and led to the gas suction pipeline.
2、工藝特點
2. Process characteristics
1)脫苯塔上段設(shè)有斷塔板,防止塔板積水,利于脫苯塔的操作。
1) The upper section of the benzene removal tower is equipped with a broken tray to prevent water accumulation and facilitate the operation of the benzene removal tower.
2)管式爐爐管采用不銹鋼材質(zhì)。
2) The tube furnace tube is made of stainless steel material.
3) 貧富油換熱器和油汽換熱器采用不銹鋼材質(zhì)。
3) The rich poor oil heat exchanger and oil vapor heat exchanger are made of stainless steel material.
4) 各貯槽放散氣體經(jīng)壓力平衡系統(tǒng)回吸煤氣管道,廢氣不外排。
4) The gas released from each storage tank is sucked back into the gas pipeline through the pressure balance system, and the exhaust gas is not discharged outside.
3、 主要技術(shù)操作指標
3. Main technical operation indicators
管式加熱爐后富油溫度190℃
Rich oil temperature after tube heating furnace 190 ℃
脫苯塔頂部溫度92℃
The top temperature of the benzene removal tower is 92 ℃
脫苯塔底部貧油溫度185℃
The lean oil temperature at the bottom of the benzene removal tower is 185 ℃
入再生器過熱蒸氣溫度400℃
The temperature of superheated steam entering the regenerator is 400 ℃
二段貧油冷卻器后貧油溫度27~29℃
The lean oil temperature after the two-stage lean oil cooler is 27-29 ℃
脫苯塔底部壓力0.04MPa
Bottom pressure of benzene removal tower 0.04MPa
再生塔頂部壓力0.05MPa
Regeneration tower top pressure 0.05MPa
4、 主要環(huán)保措施
4. Main environmental protection measures
1)各貯槽放散氣體經(jīng)壓力平衡系統(tǒng)回吸煤氣管道,廢氣不外排。
1) The gas released from each storage tank is sucked back into the gas pipeline through the pressure balance system, and the exhaust gas is not discharged outside.
2)系統(tǒng)內(nèi)的放空水、放空油和漏液集中回收進入地下放空槽,然后返回系統(tǒng),不外排。
2) The vented water, vented oil, and leaked liquid in the system are collected and recycled into the underground venting tank, and then returned to the system without being discharged.
5、主要設(shè)備的工作原理
5. Working principle of main equipment
管式爐
tubular furnace
管式爐有圓筒體的輻射室、長方體的對流室和煙囪三大部分組成。沿爐管的長度方向,熱強度的分布是不均勻的。一般小的圓筒爐,在輻射室上方設(shè)有一個由高鉻鎳合金鋼制成的輻射錐,它的輻射作用,可使爐管上部的熱強度提高,從而使爐管沿長度方向的受熱比較均勻。
A tube furnace consists of three main parts: a cylindrical radiation chamber, a rectangular convection chamber, and a chimney. The distribution of thermal intensity along the length of the furnace tube is uneven. A generally small cylindrical furnace is equipped with a radiation cone made of high chromium nickel alloy steel above the radiation chamber. Its radiation effect can increase the thermal intensity of the upper part of the furnace tube, thereby making the heating of the furnace tube along the length direction more uniform.
對流室置于輻射室之上,對流管水平放。其中緊靠輻射段的兩排橫管為過熱蒸汽管,用于將脫苯用的直接蒸汽過熱至400℃以上。其余各排管用于富油的初步加熱。
The convection chamber is placed above the radiation chamber, and the convection tube is placed horizontally. The two rows of horizontal pipes adjacent to the radiation section are superheated steam pipes, used to overheat the direct steam used for benzene removal to above 400 ℃. The remaining pipes are used for preliminary heating of the rich oil.
溫度為130℃左右的富油分兩程先進入對流段,加熱到180~200℃后再去脫苯塔。
The rich oil with a temperature of around 130 ℃ enters the convection section in two stages, and is heated to 180-200 ℃ before going to the benzene removal tower.
再生器
a regenerator
洗油再生器中部設(shè)有帶分布裝置的進料管,下部設(shè)有殘渣排出管。為了降低洗油的蒸出溫度,再生器底部設(shè)有直接蒸汽管,通入脫苯蒸餾所需的絕大部分或全部蒸汽。
There is a feed pipe with a distribution device in the middle of the wash oil regenerator, and a residue discharge pipe in the lower part. In order to reduce the distillation temperature of the wash oil, a direct steam pipe is installed at the bottom of the regenerator, which introduces most or all of the steam required for benzene removal distillation.
在富油入口管下面舍兩塊弓形隔板,以提高再生器內(nèi)洗油的蒸汽程度。在富油入口管的上面設(shè)三塊形隔板,以捕集油滴。
Place two arched partitions under the rich oil inlet pipe to increase the steam level of the wash oil in the regenerator. Install three partition plates above the rich oil inlet pipe to capture oil droplets.
富油再生的油氣和過熱水蒸氣從再生器頂部進入脫苯塔底部,作為富油脫苯蒸汽。該蒸汽中粗苯蒸汽分壓與脫苯塔熱貧油液面上粗苯蒸汽壓接近,很難使脫苯貧油含苯量再進一步降低,貧油含苯質(zhì)量含量一般在0.4%左右。
The oil and gas from the rich oil regeneration and the superheated steam enter the bottom of the benzene removal tower from the top of the regenerator as rich oil benzene removal steam. The partial pressure of crude benzene vapor in the steam is close to the pressure of crude benzene vapor on the hot lean oil surface of the benzene removal tower, making it difficult to further reduce the benzene content in the lean oil. The mass content of benzene in the lean oil is generally around 0.4%.
脫苯塔
Benzene removal tower
管式爐加熱的泡罩脫苯塔,分兩段,上段精餾段,下段提餾段。精餾段設(shè)有8塊塔板,每塊塔板上有若干個圓形泡罩,板間距為600mm。精餾段的第二層塔板及最下一層塔板為斷塔板,以便將塔板上混有冷凝水的液體引至油水分離器,將水分離后再回到塔內(nèi)下層塔板,以免塔內(nèi)因冷凝水聚集而破壞精餾塔的正常操作。
The bubble hood dehalogenation tower heated by a tube furnace is divided into two sections: the upper distillation section and the lower distillation section. The distillation section is equipped with 8 trays, each with several circular bubble caps and a spacing of 600mm between them. The second and bottom trays of the distillation section are broken trays, which allow the liquid mixed with condensed water on the trays to be directed to the oil-water separator, separated, and then returned to the lower trays inside the tower to prevent the normal operation of the distillation tower from being disrupted by the accumulation of condensed water.
提餾段設(shè)有3塊塔板,板間距為1000mm。每塊塔板上有若干個圓形高泡罩及蛇管加熱器,在塔板上保持較高的液面,使之能淹沒加熱器。重苯由提餾段底部排出。
The distillation section is equipped with three trays with a spacing of 1000mm. Each tray has several circular high bubble caps and coil heaters, which maintain a high liquid level on the tray to submerge the heaters. Heavy benzene is discharged from the bottom of the distillation section.
6、影響粗苯回收的主要因素
6. The main factors affecting the recovery of crude benzene
影響回收率的因素有煤氣和洗油中粗苯含量、煤氣流速及壓力、洗油循環(huán)量及分子量、吸收操作溫度、吸苯塔構(gòu)造。
The factors that affect the recovery rate include the crude benzene content in gas and wash oil, gas flow rate and pressure, wash oil circulation and molecular weight, absorption operating temperature, and benzene absorption tower structure.
油庫工段
Oil depot section
1、工藝說明
1. Process Description
本工段設(shè)置4個焦油貯槽(每個700m3, 存20天的焦油產(chǎn)量),接受冷凝鼓風(fēng)裝置送來的焦油,并裝火車/汽車槽車外運;設(shè)置2個粗苯貯槽(每個400m3, 存20天的粗苯產(chǎn)量),接受粗苯蒸餾裝置送來的粗苯,并裝火車/汽車槽車外運;設(shè)置2個洗油貯槽(每個100m3, 存50天的用量),用于接受外來的洗油,并定期用泵送往終冷洗苯裝置;設(shè)置2個(NaOH)堿貯槽(每臺100m3, 存20天的用量)和2個硫酸槽(每個200m3),并用泵定期送至終冷洗苯裝置和硫銨裝置。當采用火車卸車時,利用火車卸車裝置;當采用汽車裝卸車時,利用汽車裝卸車裝置。
This section is equipped with four tar storage tanks (each 700m3, storing 20 days of tar production), which receive tar from the condensing blower device and transport it by train/truck tanker; Set up 2 crude benzene storage tanks (each 400m3, with a crude benzene production capacity of 20 days), receive crude benzene from the crude benzene distillation unit, and transport it by train/truck tank truck; Set up 2 wash oil storage tanks (each 100m3, with a storage capacity of 50 days) to receive external wash oil and regularly pump it to the final cold wash benzene unit; Set up 2 NaOH alkali storage tanks (100m3 each, with a storage capacity of 20 days) and 2 sulfuric acid tanks (200m3 each), and regularly pump them to the final cold washing benzene unit and ammonium sulfate unit. When using train unloading, utilize the train unloading device; When using car loading and unloading equipment, utilize the car loading and unloading device.
2、主要環(huán)保措施
2. Main environmental protection measures
1) 各貯槽放散氣體經(jīng)壓力平衡系統(tǒng)回吸煤氣管道,廢氣不外排。
1) The gas released from each storage tank is sucked back into the gas pipeline through the pressure balance system, and the exhaust gas is not discharged outside.
2) 焦油貯槽分離水送吸煤氣管道,不外排。
2) The separated water from the tar storage tank is sent to the gas suction pipeline and is not discharged externally.
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