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CN-122006383-A - System and method for reducing pressure difference of olefin separation water scrubber

CN122006383ACN 122006383 ACN122006383 ACN 122006383ACN-122006383-A

Abstract

The application discloses a system and a method for reducing the pressure difference of an olefin separation water scrubber. The system comprises a waste alkali delivery pump, a first interface, a water washing tower circulating pump set and an injection pipeline, wherein the inlet end of the waste alkali delivery pump is connected to a waste alkali storage tank or a waste alkali discharge pipeline of an olefin separation device, the guide and leaching position of the outlet end of the waste alkali delivery pump is provided with the first interface, the water washing tower circulating pump set comprises a first circulating pump and a second circulating pump which are mutually standby, the guide and leaching interface is arranged on an inlet pipeline of the circulating pump in a standby state, the guide and leaching interface forms the second interface, and the injection pipeline is used for connecting the first interface and the second interface and conveying waste alkali to an inlet of the circulating pump in the standby state so as to enter the water washing tower. According to the scheme, the injection pipeline is arranged, so that the waste alkali liquid is accurately conveyed to the packing section of the water scrubber, the waste alkali liquid is fully mixed with the circulating water and then contacts with the oil phase attached to the surface of the packing to carry out saponification reaction, the oil phase is removed, the permeability of the packing is recovered, and the purpose of reducing the pressure difference of the water scrubber is achieved.

Inventors

  • Jing Yonggang
  • LI WEI

Assignees

  • 宁夏宝丰能源集团股份有限公司

Dates

Publication Date
20260512
Application Date
20260324

Claims (10)

  1. 1. A system (100) for reducing pressure differential in an olefin separation water scrubber, comprising: The inlet end of the waste alkali delivery pump (101) is connected to a waste alkali storage tank or a waste alkali discharge pipeline of the olefin separation device, and the waste alkali is process waste liquid containing alkaline substances generated in the operation process of the device; A water scrubber circulating pump (102) group comprising a first circulating pump (102) and a second circulating pump (102) which are mutually standby, wherein the inlet pipeline of the circulating pump (102) in standby state is provided with a shower guide interface which forms the second interface, and An injection line (103) for connecting the first interface with the second interface and for delivering spent lye to an inlet of a circulation pump (102) in a standby state for entering the water scrubber.
  2. 2. The system (100) for reducing the pressure difference in an olefin separation water scrubber according to claim 1, further comprising a first hand valve disposed at the outlet pilot shower of the spent caustic delivery pump (101) and a second hand valve disposed at the inlet pilot shower of the backup stand of the water scrubber circulation pump (102).
  3. 3. The system (100) for reducing the pressure difference in an olefin separation water scrubber according to claim 1 or 2, further comprising a pH monitoring device for monitoring the pH of the water fed outside the water scrubber to control the amount of spent lye injected.
  4. 4. The system (100) for reducing the pressure difference of an olefin separation water scrubber according to claim 2, wherein the injection line (103) is further provided with a flow regulating valve and a flow meter for precisely controlling the flow of spent lye into the water scrubber.
  5. 5. The system (100) for reducing the pressure difference across an olefin separation water scrubber according to claim 4, wherein a check valve is further provided on the injection line (103), the check valve being located downstream of the flow regulating valve for preventing water in the water scrubber from flowing back to the spent caustic effluent pump (101).
  6. 6. The system (100) for reducing the pressure difference of the olefin separation water scrubber according to claim 1, wherein the inlet pipeline and the outlet pipeline of the circulating pump (102) in a standby state are communicated with a main circulating pipeline, the main circulating pipeline is used for pressurizing the washing water at the bottom of the water scrubber through the circulating pump (102) and then conveying the washing water to the upper part of the tower body, and the waste alkali liquid injected from the second interface flows through the standby pump cavity and then is converged into the main circulating pipeline and enters the packing section of the water scrubber along with the circulating water.
  7. 7. The system (100) for reducing the pressure difference in an olefin separation water scrubber according to claim 1, wherein the injection line (103) is provided with sampling ports for periodic extraction of spent lye samples for analysis of their alkalinity or oil content.
  8. 8. The system (100) for reducing the pressure difference across an olefin separation water scrubber according to claim 1, further comprising a pressure difference transmitter disposed on the water scrubber and an alarm device coupled to the pressure difference transmitter for sending a warning signal when the pressure difference exceeds a predetermined threshold.
  9. 9. A method of reducing pressure differential using the system (100) for reducing pressure differential in an olefin separation water scrubber of any of claims 1-8, comprising the steps of: starting a waste alkali delivery pump (101), and opening a first interface arranged at the outlet guide shower position of the waste alkali delivery pump; opening a second interface at a shower guide interface on an inlet pipeline of the circulating pump (102) in a standby state; The waste alkali liquid is conveyed from the waste alkali delivery pump (101) to the inlet of the circulating pump (102) in a standby state through the injection pipeline (103) and then enters the water scrubber.
  10. 10. The method according to claim 9, characterized in that the pH value of the water fed outside the water scrubber is monitored in real time and a flow regulating valve arranged on the injection line (103) is adjusted in accordance with the monitored pH value to control the injection flow of spent lye.

Description

System and method for reducing pressure difference of olefin separation water scrubber Technical Field The present application relates generally to the field of operation and maintenance of a water wash column in an olefin separation process. More particularly, the application relates to a system for reducing the pressure difference of an olefin separation water scrubber, and further relates to a method for reducing the pressure difference by utilizing the system for reducing the pressure difference of the olefin separation water scrubber. Background The olefin separation device is one of the core sections of the coal-to-olefin or petroleum-to-olefin process, and has the function of compressing, cooling and separating mixed gas generated by methanol conversion or hydrocarbon cracking to obtain polymer grade ethylene and propylene products. In the olefin separation process, the water scrubber is one of key equipment and is used for washing catalyst fine powder, unreacted substances and a small amount of oil phase impurities carried in the reaction gas so as to ensure the normal operation of the subsequent alkaline scrubber. Currently, during normal operation, olefin separation plant water scrubbers typically employ turbine condensate and purified water as a source of scrubbing water. However, the purified water tends to carry small amounts of catalyst fines and oil phase medium. When the water purifier is used for a long time, the oil phase medium can be gradually attached to the surface of the packing of the water scrubber, so that the porosity of the packing layer is reduced, the air flow channel is blocked, and the pressure difference of the water scrubber is continuously increased. When the pressure difference is too high, the feed of the alkaline washing tower is brought with water, the amount of red oil generated in the tower is increased, and even the fluctuation of the device is caused when the pressure difference is severe, the device is forced to drop, run or stop for cleaning. In the prior art, when the pressure difference of the water scrubber rises to influence the operation of the device, the cut-out system of the water scrubber is usually required to be cleaned off line or the packing is required to be replaced. The treatment mode is time-consuming and labor-consuming, affects long-period operation of the device, and increases equipment maintenance cost and material loss. Meanwhile, the olefin separation device can generate a certain amount of waste lye in the operation process, the waste lye contains alkaline substances and a small amount of oil phase, and the traditional treatment mode is to discharge the waste lye to a sewage treatment system, so that the pollution discharge cost is increased, and the alkaline components possibly having the utilization value are wasted. In view of the foregoing, it is desirable to provide a system and method for reducing the pressure difference of an olefin separation water scrubber so as to effectively reduce the pressure difference of the water scrubber without interrupting the operation of the device, and simultaneously realize the recycling of waste lye. Disclosure of Invention To address at least one or more of the above-mentioned problems, the present application provides, in various aspects, a system and method for reducing pressure differential across an olefin separation water scrubber. In a first aspect, the application provides a system for reducing the pressure difference of an olefin separation water scrubber, which comprises a waste alkali delivery pump, a water scrubber circulating pump set and an injection pipeline, wherein the inlet end of the waste alkali delivery pump is connected to a waste alkali storage tank or a waste alkali discharge pipeline of an olefin separation device, the waste alkali is process waste liquid containing alkaline substances generated in the operation process of the device, a first interface is arranged at a guide position of the outlet end of the waste alkali, the water scrubber circulating pump set comprises a first circulating pump and a second circulating pump which are mutually standby, the inlet pipeline of the circulating pump in a standby state is provided with a guide interface, the guide interface forms the second interface, and the injection pipeline is used for connecting the first interface and the second interface and conveying the waste alkali to an inlet of the circulating pump in a standby state so as to enter the water scrubber. In some embodiments, the system further comprises a first hand valve disposed at the waste caustic outfeed pump shower guide and a second hand valve disposed at the water scrubber circulation pump stand-by station inlet shower guide. In some embodiments, the system further comprises a pH monitoring device for monitoring the pH of the water delivered outside the water scrubber to control the amount of spent lye injected. In some embodiments, the injection pipeline is also