Catalytic shutdown, oil removal and line cleaning plan

Thread Content

1. Oil withdrawal plans related to light dirty oil connections (including primary and secondary flow, cold return, top circulation, diesel, and naphtha). Things to note: A: Purge processing principles and precautions must be strictly followed, and accidents such as damage to equipment and oil and gas cross-talk are strictly prohibited. Pay special attention to prevent the cold exchange equipment from being stressed. B: In principle, it is not allowed to discharge oil products into ground ditches or underground wells. C: Before draining the oil, the process must be conducted first. Note that the three valves inside the device must be opened (at the crude steam valve group, at the stable boundary, and at the southeast corner of the air compressor). At the same time, it is necessary to coordinate the flow of light dirty oil in the tank area into an empty tank and open the valves. D: There are many processes involved. Pay attention to the opening and closing of valves. You must open what should be opened and close what should be closed to prevent oil from flowing everywhere. E: It is strictly prohibited to send a large amount of high-temperature oil and steam to the tank area, which will cause danger to the tank area. 1. Considering that there will be a large amount of water inside the system after the shutdown, which will affect the temperature rise of the stable part when the operation is started, the No. 1 Middle School does not plan to do a comprehensive oil removal and cleaning line, but only partial treatment. The plan is as follows: (1) The extraction part uses a pump to pump the oil inside the pipeline to the light dirty oil line. (2) The oil after the FV1209 regulating valve group uses the height difference and the pressure after steam injection in the tower to self-pressurize to the light dirty oil line. Pay attention to the changes in the process, which mainly refers to opening and closing valves. (3) The pipeline treatment is to use the steam in the tower to return from top to bottom to the venting place in front of the FV1209 regulating valve group for condensation and venting. 2. Considering that the top circulation part may be dirty inside, a comprehensive purging treatment is planned. (1) The extraction part uses a pump to pump the oil inside the pipeline to the light dirty oil line. It must be processed multiple times to ensure that the oil is drained cleanly. (2) The oil after the FV1204 regulating valve group uses the height difference and the pressure after steam injection in the tower to self-pressurize to the light dirty oil line. Pay attention to the changes in the process, which mainly refers to opening and closing valves. (3) After multiple treatments, use top-circulation water supply, follow the normal process, take the light oil line to the tank area, and adjust the valve group's venting to see water for a period of time before stopping and releasing water. After draining the water, prepare to inject steam. (4) The steam injection point is basically to use steam injection before and after the pump, especially for the back purge of the pump. Steam injection after the pump should be used, along the process through E3204/ABCD (be sure to close the inlet and outlet of the waterway, open the vent to let the water out, to prevent the steam from being unable to pass through or the pressure being suppressed to damage the equipment. ； Attention should also be paid to the temperature control valve and flow regulating valve passed by) until venting at FV1204. Before that, the purged oil must be returned to the light dirty oil line, and then the vent valve here should be opened for venting. The back path of the regulating valve is to use the steam and pressure in the tower to return to the regulating valve for venting or directly lead the steam into the tower. 3. In the diesel part, a pump is used to return all the oil to the light dirty oil line. Be careful not to return to the refined part. After the diesel stripper has been evacuated several times, open the diesel stripper to strip the steam and divide it into two routes, one to return to the tower and the other to the pump for venting. Inject steam at the pump outlet through E3206, E3210/AB, E3212/AB, E3214 (note: (E3213/AB is not processed) After the light dirty oil line from the regulating valve group is very hot, open the venting of the flow regulating valve group to check whether there is still oil. When it is almost the same, switch to venting the flow valve group to drain condensation. 4. Remove the oil from the crude gasoline system (V3203). (1) After shutdown, before processing the first intermediate and top cycles, the crude gasoline pump must be started to pump water to top the crude gasoline to charge the top cycle, and the cold reflux to the top cycle must be cleaned, and the valve must be closed after cleaning. (2) After the steam is injected into the tower, a large amount of residual oil vapor will enter the V3203 after cooling. The oil in the container is pumped out into the light dirty oil line with a pump. It needs to be pumped out multiple times, and finally the steam is introduced to the pump inlet for venting. (3) The V3203 oil collecting line leads steam to the valve group for venting and then to the pump outlet for venting. 2. Oil removal and cleaning line of raw oil 1. Follow the cleaning principles and precautions. Multiple steam injection points can be opened according to the situation. After a large amount of steam is injected, the pressure inside T3201 must be observed and excessive pressure is strictly prohibited. 2. Under normal circumstances, the line is swept from the boundary valve of the device to the inside of the device. When starting work outside the device, just turn on the heating cable. It is necessary to coordinate the tank area not to damage pipelines and flanges due to heat tracing problems. 3. The line sweeping process is briefly described as follows:: (1) Supply steam to the raw material valve group (note that the corresponding valve must be closed), and proceed to the inside of the device. Sweep the oil into the raw material buffer tank (V3201). The oil in V3201 is pumped out to the rear path with pump P3201. The steam is introduced to the inlet of P3201 for venting, and the outlet of P3201 is used to supply steam. Steam, go to E3215/AB after passing through LV1207, go to the raw material return self-protection valve group, take XOV1102, return to the line and enter T3201, use P3209/ABC to pump the oil to the back road, which needs to be processed multiple times, otherwise there will be a lot of oil that needs to be vented. (2) Normally fed XCV1101 can be processed by steam injection on the preheating wire at the nozzle. The method is:: First, inject steam to purge the raw material preheating pipeline. After the purging is completed, close the second preheated valve and the valve that is about to enter the accident return line. Open the first valve for raw material preheating, inject steam into the circular raw material pipeline, sweep the internal raw materials downward to XCV1101, and merge with the other steam to enter T3201. Note: This part can be done in advance. (3) Also being processed at the same time is the oil slurry refining pipeline. The processing method is: Close the first valve of the oil slurry refining main pipe, inject steam behind the valve for purge, and then merge with the raw materials through FV1102 and enter T3201. It can be closed early after the processing is qualified. 3. Oil withdrawal and sweeping line back to the refining system: (This part requires all oil products to be swept to T3201, so it must be synchronized with the purging of raw oil) 1. The return oil pump must be evacuated multiple times, and the pump must be started repeatedly intermittently until the oil in V3202 is clean. Close the V3202 outlet valve, (open the vent in front of the valve), open the steam injection point behind the valve, open the inlet and outlet steam injection points of the pump, and sweep the line backward. 2. Return to refining The return oil passes through the preheating line and the return line, and then enters the fractionation tower after being merged with the raw materials. This part must be carried out in advance and synchronized with the processing of raw materials, otherwise T3201 will be polluted again. 3. The return to the refining tower is through the return tower regulating valve group FV1211 to T3201. 4. The second middle school is through E3208, three-way valve group TV1205, and FV1216 before entering T3201. Note: When cleaning the line, the three-way valve group should be opened and closed appropriately, and the hot path should be cleaned. 5. When cleaning the line, since there are relatively many branches, it can be carried out individually one by one to achieve a comprehensive purge. After the basic processing of the back refining and the second middle school is completed, turn on the steam sweeping line at the back refining nozzle and E3208. 4. Oil slurry system oil removal and cleaning line. 1. Things to note: (1) Since the oil in the slurry system is heavy and the system is large, it is difficult to handle, so you must be careful and patient when handling it. (2) The principle of oil removal is that oil products are not allowed to be put into the ditch and should be returned to the tank area as much as possible. When removing oil, process it from front to back, and do not miss the processing location. (3) E3215/AB and E3216/AB need to be processed, so they must be processed thoroughly. (4) There will be a lot of oil in the tray in the tower, which will drop to the bottom of the tower, but it will take a certain amount of time, so the oil must be pumped multiple times to return the oil to the tank area. Note that the pump must be stopped immediately after it is evacuated. (5) Process the part after the oil slurry returns to FC1215 in advance by closing the rear hand valve of FV1215 and opening the steam injection and purging to T3201. 2. The oil withdrawal process will not be described again. Just follow the basic normal process. Note that the oil is withdrawn to the unqualified tank of the oil slurry, and the valve at the wall root of the oil slurry returning up and down the tower must be closed to prevent circulation and failure to withdraw oil. In addition, be sure to make good use of the pipeline connected to the oil slurry in front of the oil slurry return regulating valve. 3. Line sweeping process and basic methods: (1) After the raw material, refining oil, and slurry refining purge processing is basically completed, P3209 can be purged after multiple oil withdrawals. The purpose is not to leave too much oil inside the device. (2) Close the extraction valve at the bottom of T3201, open the vent at the bottom of the tower, or vent at P3209/ABC without closing the valve at the bottom of the tower (it is smaller here). (3) Steam is supplied from the extraction valve at the bottom of T3201, steam is supplied from the outlet of P3209, and steam is supplied from other steam injection points in the process. According to: T3201→P3209→E3215→E3216→E3218→unqualified to the tank area. Note that: Close the cold and hot circuit regulating valves of the oil slurry, and guide the oil from the cold circuit to the external throw line. Here we need to jointly deal with the FV1218 valve group pipeline. The processing method of the FV1218 valve group pipeline is:: After the above mentioned process has been carried out or carried out for a period of time, the steam is directed to the FV1218 valve group, and then returned to the outer throw line to the oil slurry tank area. Be careful not to put water-containing oil slurry into the tank, and notify the tank area to change the line or vent it. (4) Open the relevant valves of the oil slurry hot and cold circuit regulating valve, close the valve leading from the cold circuit to the external throw line, and follow the procedure: T3201→P3209→E3215→E3216→FV1215 upper return and outer throw connecting line (cannot be connected to E3218)→unqualified line→tank area. At the same time, attention should be paid to handling the oil slurry. The method is: Close the lower return root valve of the T3201 vessel wall, open the steam injection point in front of the valve, sweep downward in reverse direction to the main pipe after the hot and cold circuits merge, merge with the sweep steam flowing through the upper return, and take the connecting line to the tank area.