Hubei Jinyuan chemical co., ltd
Internship post change
One: Company Profile
Hubei Jinyuan Chemical Co., Ltd. is a national large-scale second-class chemical enterprise, which was founded in 1969. The company was formerly known as Hubei Western Chemical Plant, and changed its name to Hubei Jinyuan Chemical Co., Ltd. in 2003 (1 18). Now it is a private joint-stock enterprise.
The company is close to Jiaozhi Railway, 207 national highway and the newly-built Jingxiang Expressway. The company has a special railway connected with Jiaozhi Railway, which has the characteristics of convenient transportation and superior geographical position. The company covers an area of 41.2000 square meters, with total assets of1.700 million yuan and more than .7000 employees, including 6 1.9 professional technicians. The main products and annual production capacity are: total ammonia (synthetic ammonia+crude methanol) 65,438+200,000 tons, compound fertilizer 50,000 tons, dilute nitric acid 65,438+200,000 tons, ammonium nitrate 65,438+300,000 tons, concentrated nitric acid 50,000 tons, refined methanol 40,000 tons, formaldehyde 40,000 tons, sodium nitrate 04,000 tons and sodium methoxide 0. Among them, the leading products, ammonium nitrate and concentrated nitric acid, were awarded the title of "excellent brand" by the Hubei Provincial People's Government; Methanol products are national first-class products; The company consists of instrument workshop, quality inspection center, railway department and potassium nitrate office. The company uses coal cakes, that is, coal sticks, as its main fuel.
Second, "change" the content of internship.
"Shift" post is the intermediate link of NH3 synthesis section. The purpose is to obtain H2 through the reaction of carbon monoxide and steam, and adopt DCS automatic operation system.
1. Production principle and process flow
(1) production principle:
Carbon monoxide in semi-water gas reacts with water vapor under the action of catalyst and is converted into hydrogen and carbon dioxide.
Carbon monoxide+H2O = carbon dioxide +H2+Q
② reaction mechanism
H2O↑ = [K]O+ H2
[K]O+CO =[K]+ CO2
[k]- catalyst
O-adsorbed oxygen
③ production process
definition
Low temperature change: upper part of large shift furnace.
Low temperature transformer: the lower part of large shift furnace.
Three low changes: small shift furnace.
Main steam: refers to the steam added after the outlet separator of the saturation tower, which is the steam addition point during normal production.
Auxiliary steam: refers to the steam added from the humidifier, which is the supplementary point of steam at the beginning of shift start-up or under abnormal conditions such as high oxygen.
Main line: refers to the bypass where the gas in the saturation tower directly enters the pre-reformer without primary heat exchange and primary heat exchange. It is mainly used to adjust the inlet temperature of the pre-reformer.
Small secondary line: refers to the bypass that the shift gas of the second low temperature change directly enters the third low temperature change without primary heat exchange and primary heat exchange. It is mainly used to adjust the temperature of three low temperature changes.
Vulcanization secondary line: refers to a φ2 19 secondary line leading out from the semi-water gas main pipe and entering the outlet valve of the blower and in front of the small electric furnace. It is mainly used for system gas supply in the process of catalyst vulcanization, and can also be used for heating the catalyst without opening the blower.
process flow
After the semi-water gas is preliminarily separated by the separator, it enters the screen oil filter to further remove oil impurities, then enters the saturation tower from the lower part, and contacts with the circulating hot water sprayed from the top of the tower from bottom to top for mass transfer and heat transfer. After heating, semi-water gas comes out from the top of the saturation tower and enters the separator. After adding a certain amount of steam, it enters the initial pipe and exchanges heat with the shift gas from the main pipe outside the pipe. Then it enters the main pipe to exchange heat with the shift gas from the second low temperature outside the pipe, which further increases the temperature of semi-water gas. The high-temperature gas from the main pipe is mixed with the temperature-adjusting cold gas from the main pipe, and then enters the pre-reforming furnace from the top of the pre-reforming furnace. In the pre-reformer, the gas is further purified under the action of the purifying agent. The gas leaves the pre-reformer and enters the first humidifier, and then enters the low temperature change after spraying water. The reacted gas enters the second humidifier and the second low temperature change after spraying water. The reacted gas enters the main heat exchanger and the initial pipe, and enters the third low temperature change after exchanging heat with semi-water gas in the pipe. The reacted gas enters the water heater pipe. After being cooled by hot water in the pipe, it enters the hot water tower from the lower part of the hot water tower and contacts with the circulating hot water coming down from the saturation tower from bottom to top. After further heat recovery, it enters the shift gas cooler to cool the shift gas to ≤50℃, and the water is separated by the separator and sent to the desulfurization section.
After the hot water tower recovers the heat of the shift gas, the circulating hot water comes out from the bottom of the tower and enters the hot water circulating pump. After being pressurized, it is sent to a water heater to exchange heat with the shift gas outside the pipe, so that the temperature of hot water is further increased, sprayed from top to bottom at the top of the saturation tower, contacted with semi-water gas in countercurrent for heat exchange, and then flows out from the bottom of the saturation tower and enters the hot water tower for circulation.
The circulating water of the saturated hot water tower system is supplemented to the supplementary water tank by the condensate from the copper liquid regeneration system in the synthesis workshop and the desalted water from the shift gas cooler, and then is supplemented to the hot water tower after being pressurized by the supplementary water pump.
The pure water sent by 22 1 job number is sent to the pure water storage tank and pressurized by the humidifier spray pump for use by the humidifier. Desalinated water from the synthesis workshop enters the shift gas cooler, and the shift gas from the inter-tube cooling hot water tower returns to 22 1 deaerator after heating, and a small amount is used as supplementary water for the condensate tank.
Two process indicators
2. 1 process parameters
2. 1. 1 flow rate 2. 1.2 temperature serial number content index unit 1 gas temperature in saturated tower ≤40℃ 2 gas temperature in saturated tower 10 ~ 130℃ 3 inlet temperature of pre-reforming furnace 200 ~. A low variable hot spot temperature 10℃ 6, two low variable inlet temperatures 200 ~ 250℃ 7, two low variable hot spot temperatures 10℃ 8, three low variable inlet temperatures 180 ~ 220℃ 9, three low variable hot spot temperatures10℃10. 1.3 pressure (gauge pressure) serial number content index unit 1 cooler outlet shift gas pressure ≤ 1.6 MPa 2 high-pressure steam pressure 2.0~2.5 MPa 3 humidifier water pressure ≥2.0 MPa 4 electric furnace working pressure < < 0.2 MPa 5 vulcanizing tank working pressure < < 0.3 MPa 6 blower wind pressure < 0. 049 MPa 2. 1.4 level serial number content index unit 1 saturation tower level 40 ~ 70% 2 hot water tower level 40 ~ 70% 3 makeup water tank level 60 ~ 80% 4 pure water tank level 70 ~ 90% 2. 1.5 Other 2.2 process quality index serial number content index unit 6544. The content of +0 CO at the outlet of the third low-voltage transformer is less than or equal to 6.0%; the content of H2S at the outlet of the third low-voltage transformer is less than or equal to170 ~ 240mg/nm33; the content of O2 in semi-water gas is less than or equal to 0.5%; the total solids of circulating water in the saturated hot water tower are less than 0.05%; and the PH value of circulating water in the saturated hot water tower is less than or equal to ≤0.5 μS/cm 3.
This position is operated by DCS system, which mainly detects CO content and catalyst temperature. By adjusting the temperature and steam addition, the CO content at the outlet of "Three Low" is adjusted to no more than 6.0%, which is determined according to the subsequent methanol output. Temperature control is mainly to control the temperature within the active range of the catalyst. Too high or too low temperature is not conducive to the catalytic activity of the catalyst.
(1) According to the dispatching instruction, control the carbon monoxide content in the shift gas to meet the production requirements. Careful operation, try to prolong the service life of catalyst and reduce steam consumption.
(2) Control the temperature and system pressure of the shift furnace, and timely discharge the separator and the drainage liquid to ensure the safety and stability of production.
(3) Control the liquid level of the saturation tower and hot water tower to prevent liquid entrainment and gas cross-talk.
(4) Check on time, and report to the monitor in time if any abnormality such as running, running, dripping and leakage is found.
⑤ According to the water quality of the saturated hot water tower, timely adjust the ammonia consumption and the sewage discharge of the saturated tower to reduce environmental pollution.
6. Fill in the post records on time and truthfully, and do not forge or make false records.
⑦ Be responsible for the oiling and lubrication of transmission equipment and valve lead screw in this position, and the rotation of standby transmission equipment in this position.
4. Catalyst: Co-Mo series
The main active component of the Co-Mo sulfur-resistant catalyst is molybdenum oxide, with cobalt oxide as an assistant and alumina as a carrier. The activity of cobalt molybdenum oxide is much less than its sulfide, so it is necessary to convert MoO3 and CoO into MoS2 and CoS before use. The reaction is as follows:
Cs2+4h2h2s+CH4–246kJ/mol
CoO+H2S CoS+H2O– 13.4 kj/mol
Molybdenum trioxide+2H2S+H2 Molybdenum disulfide+3H2O–48.1kj/mol
5. Equipment and its packaging method
1 and 1 semi-water gas separator.
φ 1200×3740
2. 1 screen oil filter.
Built-in stainless steel mesh packaging is 450 mm high.
3. 1 saturated hot water tower.
Saturation tower: φ2600× 19 140, stainless steel structured packing, 9000mm high.
Hot water tower: φ2800× 18000 stainless steel structured packing with a height of 8000mm.
4. 1 after-tower separator.
φ 1200×6800 built-in stainless steel wire mesh packing is 300mm high.
5. 1 main heat exchanger.
φ 1000×4200 heat exchange area f = 165438+500 m2φ25×2.5 tube.
6. 1 main heat exchanger.
φ 1000×7433 heat exchange area F=440m2.
7. 1 transformer front furnace
φ2800× 1 1282 200mm lined with refractory concrete.
Leave the first paragraph blank; The second stage is filled with alumina ball (purifying agent) 7m3, and the third stage is equipped with 9 m3 antitoxic agent and 3 m3 low temperature shift catalyst.
8. 1 first humidifier
φ 1600×5735 is filled with 3.8m3 stainless steel rectangular saddle ring packing, and the upper part is equipped with impact atomizing nozzle GWBT-350-600 1 1.
9. 1 large shift furnace
φ3000× 19260 first-stage filling10m3; Low temperature shift catalyst; The second stage is filled with 4 m3 low temperature shift catalyst, the third stage is filled with 1 1 m3 low temperature shift catalyst, and the second stage and the third stage are connected in the furnace.
10 and 1 sec humidifier.
φ 1600×5735 is filled with 3.8m3 stainless steel rectangular saddle ring packing, and the upper part is equipped with impact atomizing nozzle GWBT-650-600 1 1.
1 1, 1 small shift furnace
φ3000× 1 1282 The upper part of the first section is filled with 2 m3 of antitoxic agent, and the lower part is filled with12.5 m3; Low temperature shift catalyst; The second stage is filled with low temperature shift catalyst15.5m3.
12, 1 water heater
φ 1000×7433 heat exchange area F=440m2.
13 and 1 shift gas cooler.
Φ1200× 6442 heat exchange area f = F=460m2 φ 19×2 2 tubes 1839.
14 and 1 shift gas separator.
φ 1200×3740
15, roots blower 1.
R60×63 air volume 158.4m3/min wind pressure 0.049MPa motor power 185kw.
16, 1 small electric furnace
φ800×7500 working pressure is 0.2MPa, and total power 10× 54 = 540 kW.
17, 1 large electric furnace
φ 1200×7780 working pressure 0.4MPa total power 10× 99 = 990 kW.
18, 1 vulcanizing tank
φ2500×3400
19, 1 makeup water storage tank.
φ2040×4220
20. Two supply pumps.
DG25-50×6 motor JO2-9 1-2 has a lift of 30m, a flow of 25m3/h and a power of 55KW.
2 1 and 1 pure water storage tank.
φ2000×3000
22.2 sets of humidifier spray pump
2GC-5×8 head, 250m flow 10m3/h, 30KW 23 motor power, 3 hot water circulating pumps.
150RG-56 Two motors Y250M-4 with a lift of 56m, a flow rate of 190m3/h and a power of 55KW.
100 r-57 53.5m lift, 1 10m3/h flow, matching motor Y200L 1-2, with power of 30KW.
25, after the tower separator:
Specification: φ2000×30h = 37000
26. Solution circulating pump (2 sets)
Model: 250–DF–60× 5q = 420m3/h h = 300m.
N= 1487 rpm N=630 kw G = 2250kg kg V=6000 volts.
27. Foam pumps (two sets)
Model: IH50–32–20q =12.5m3/hh = 50m.
N = 2900rpm to n = 5.5kW kw G = 58kg kg.
28, underground tank solution pump
Model: 4fb–12q =100.8m3/hr.
N = 2900rpm to n = 55kW G=350kg.
29, flotation tank
Specification: φ 3300–4200×10h = 9443v = 91.0m3.
30. Fuel injector (12)
3 1, circulation tank (two)
Specification: φ 6000× 8h = 6440v =170m3g =11430kg.
32, the middle foam tank
Specification: φ 3000× 8 h = 4945g = 4305kg.
33, high groove
Specification: φ 3000× 6V =13m3h = 2825g = 3241kg.
Preventive measures for common accidents
Preventive measures for the cause of the accident The temperature of catalyst layer exceeds the standard ① The content of carbon monoxide or oxygen in semi-water gas increases; ② steam ratio is small; (3) the circulating hot water pump trips or takes time; (4) The instrument indication is inaccurate and the temperature is false (1). Always observe the instrument display; (2) Always contact the analysis room to find out the gas composition; (3) Check the circulating hot water pump and auxiliary pipeline brake frequently. Excessive gas pressure ① compressor reversal; (2) the scheduling contact is not timely; (3) system pressure; (4) The instrument shows an error. ① When the compressor is reversed, pay attention to the outlet pressure gauge; (2) redundant scheduling contact; (3) Always observe and check the primary and secondary gas pressure meters. Gas cap phenomenon ① There is little water at the entrance of saturated hot water tower; ② Water pressure is lower than air pressure; (3) The hot water pump trips or takes time. (1) Strengthen inspection to keep the liquid level in the saturation tower; (2) Always pay attention to the hot water flowmeter and saturate his outlet thermometer; (3) to prevent the gas pressure is too high or the water pressure is too low; ④ Check the hot water pump at the airport. Carbon monoxide in shift gas exceeds the standard ① The hot spot temperature of catalyst layer is low; ② The gas-steam ratio is too small; ③ Hydrogen sulfide poisoning of catalyst; (4) catalyst aging (5) gas heat exchanger tube and ceiling leakage; ⑥ The tubes of the intermediate heat exchanger are arranged, and the ceiling leaks. ① Adjust the opening of auxiliary line or cold shock; (2) increase the steam quantity and increase the gas-steam ratio; (3) Improve desulfurization efficiency, increase steam quantity and restore catalyst activity; (4) increase the operating temperature and replace the catalyst when stopping; ⑤ Determine the composition of shift gas in each heat exchanger to determine which one it is, and repair or replace it immediately when the air leakage is serious. The hot spot temperature of catalytic layer suddenly drops: ① CO content in semi-water gas drops; (2) The system load is reduced and too much steam is added; (3) Steam or gas with water; (4) The auxiliary line or cold shock is too large; ⑤ Catalyst poisoning; ⑥ Thermometer indication is not allowed. (1) often observe the far infrared indicator secondary table of carbon monoxide content in semi-water gas; (2) reduce the amount of steam; (3) reducing the amount of steam or gas and discharging water side by side; ④ Adjust the opening of auxiliary line or cold shock; ⑤ To increase the operating temperature, the catalyst needs to be replaced; ⑥ Check and correct the thermometer, and the hot spot temperature of the catalyst layer rises sharply. ① The content of carbon monoxide in semi-water gas increased. (2) The increase of system load or low steam pressure leads to the decrease of steam ratio; (3) The secondary line has a large range of cold shock; (4) The thermometer is out of order and the indication is inaccurate. (1) frequently observe the seCOndary indicator table of intelligent light co content in semi-water gas, and contact the chemist to analyze the composition of semi-water gas; (2) increasing steam quantity and steam ratio; ③ Adjust auxiliary line and cold shock opening; (4) Contact the instrument worker to repair the watch in time. Step 6 practice feeling
During my eight days as an intern in the factory, I had many feelings. I left school, saw the real factory, saw the real workers, saw the real society, felt the difference between school and society for the first time, left school, and everything was not so superior. Living environment, resources, people and so on have all changed. In the factory, we thoroughly understood the factory and saw the working and living conditions of the workers. I deeply feel the importance of knowledge. Only by mastering solid professional knowledge can we lay a good foundation for our future foothold in society.
In the future study life, I will use the experience brought by internship to guide my study life and work hard for a better tomorrow!