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CN-121978297-A - On-line monitoring method for PH value of hot water of converter in calcium carbide polyvinyl chloride production

CN121978297ACN 121978297 ACN121978297 ACN 121978297ACN-121978297-A

Abstract

The invention discloses a method for monitoring the PH value of hot water of a converter in the production of polyvinyl chloride by a calcium carbide method, which belongs to the technical field of polyvinyl chloride production and comprises the following steps that acetylene gas and hydrogen chloride gas generate chloroethylene and emit heat under the heating and catalytic reaction of a catalyst in a converter tube array, hot water flows through the exterior of the converter tube array, enters a hot water return pipe and is stored in a hot water tank, then enters a PH value on-line detector through a valve, a hot water pump and a branch of a hot water upper pipe, circulating cooling water enters the PH value on-line detector through a circulating cooling water upper pipe, then is discharged from the circulating cooling water return pipe, indirectly cools the hot water entering the PH value on-line detector, and the PH value on-line detector continuously monitors the PH value of the hot water entering the converter tube array on line and alarms when the PH value exceeds a preset value.

Inventors

  • WANG WENMING
  • WANG QIANG
  • ZHAO AIMIN
  • XI MIN
  • CHEN TIANYU
  • TANG YUANSHEN
  • YANG XINFEI

Assignees

  • 新疆中泰化学托克逊能化有限公司
  • 新疆中泰化学股份有限公司

Dates

Publication Date
20260505
Application Date
20260130

Claims (6)

  1. 1. The online monitoring method for the PH value of the hot water of the converter in the production of the polyvinyl chloride by the calcium carbide method is characterized by comprising the following steps: S1, generating chloroethylene and releasing heat under the heating and catalytic reaction of a catalyst in a converter tube, wherein hot water is circulated outside the converter tube; s2, hot water flowing through the surface of the converter tube array enters a hot water return tube (2) and is stored in a hot water tank (1), and then enters a PH value on-line detector (5) through a valve (10), a hot water pump (9) and branches of a hot water supply tube (6); S3, circulating cooling water enters the PH value on-line detector (5) through a circulating cooling water inlet pipe (8), and then is discharged from a circulating cooling water return pipe (7) to the PH value on-line detector (5), so that hot water entering the PH value on-line detector (5) is indirectly cooled; S4, continuously monitoring the PH value of the hot water entering the PH value on line by a PH value on-line detector (5) and giving an alarm when the PH value exceeds a preset value; The supporting device of converter hot water PH value on-line monitoring method in the calcium carbide process polyvinyl chloride production comprises a hot water tank (1), wherein a hot water return pipe (2) is connected to the upper end of one side of the hot water tank (1), a steam pipe (3) is connected to one side of the top of the hot water tank (1), a hot water tank water supplementing pipe (4) is connected to the middle of the top of the hot water tank (1), a PH value on-line detector (5) is connected to one side bottom branch of the hot water tank (1), a circulating cooling water inlet pipe (8) is connected to the water inlet of the PH value on-line detector (5), a circulating cooling water return pipe (7) is connected to the water outlet of the PH value on-line detector (5), a hot water inlet pipe (6) is connected to the detection port inlet of the PH value on-line detector (5), a valve (10) is further connected to the bottom branch of the hot water tank (1), a hot water pump (9) is connected to one end of the valve (10), and the output end of the hot water pump (9) is connected to the branch pipe of the hot water inlet pipe (6).
  2. 2. The online monitoring method for the PH value of the hot water of the converter in the production of the polyvinyl chloride by the calcium carbide method according to claim 1 is characterized in that the hot water tank (1) is correspondingly connected with the water inlets of the hot water return pipe (2), the steam pipe (3) and the hot water tank water supplementing pipe (4) through valves (10).
  3. 3. The online monitoring method for the PH value of the hot water of the converter in the production of the polyvinyl chloride by the calcium carbide method according to claim 1, wherein in the step S3, the connection mode of the PH value online detector (5) detection port and outlet is one of connection with a branch pipe at the bottom end of one side of the hot water tank (1), direct connection with the bottom end of one side of the hot water tank (1) and direct connection with the upper end of one side of the hot water tank (1).
  4. 4. The online monitoring method of the PH value of the hot water of the converter in the production of the polyvinyl chloride by the calcium carbide method according to claim 1, wherein in the step S2, a water collecting tank (11) is connected to the outlet of a detection port of the PH value online detector (5), a water collecting tank pump (12) is connected to the outlet end of the water collecting tank (11), and the water draining end of the water collecting tank pump (12) is connected with one of a branch pipe line connected with the bottom end of one side of the hot water tank (1), a direct connection with the bottom end of one side of the hot water tank (1) and a direct connection with the upper end of one side of the hot water tank (1).
  5. 5. The online monitoring method for the PH value of the hot water of the converter in the production of polyvinyl chloride by the calcium carbide method according to claim 1, wherein in the step S2, a branch pipeline of the hot water return pipe (2) is connected with a detection port inlet of a PH value online detector (5), and a detection port outlet of the PH value online detector (5) is connected with one side bottom end of a hot water tank (1) and one side upper end of the hot water tank (1).
  6. 6. The online monitoring method of the PH value of the hot water of the converter in the production of the polyvinyl chloride by the calcium carbide method according to claim 1, wherein in the step S2, a water collecting tank (11) is connected to a detection port outlet of the PH value online detector (5), a water collecting tank pump (12) is connected to an outlet end of the water collecting tank (11), and a water discharging end of the water collecting tank pump (12) is connected with a main pipeline of a hot water return pipe (2), a branch pipeline of the bottom end of one side of a hot water tank (1), a bottom end of one side of the hot water tank (1) and an upper end of one side of the hot water tank (1).

Description

On-line monitoring method for PH value of hot water of converter in calcium carbide polyvinyl chloride production Technical Field The invention belongs to the technical field of polyvinyl chloride production, and particularly relates to an online monitoring method for the PH value of hot water of a converter in the production of polyvinyl chloride by a calcium carbide method. Background The calcium carbide method is a main process for producing polyvinyl chloride in China, and occupies 80% of industry productivity. The traditional process adopts a mercury-containing catalyst, and has serious environmental pollution problem. The mercury-free gold-based catalyst industrially applied in 2024 breaks through the technical bottleneck, and realizes the conversion rate of acetylene of 85% -99.5% and the selectivity of chloroethylene of over 99.5% by a nitrogen-oxygen doped active carbon carrier and high-valence gold stable dispersion technology. When polyvinyl chloride is produced by the calcium carbide method at present, acetylene gas and hydrogen chloride gas are heated in a converter tube array and are subjected to catalytic reaction by a catalyst to generate vinyl chloride and emit heat, hot water is at 97+/-2 ℃ outside the converter tube array, and the hot water plays a role in heating the acetylene gas and the hydrogen chloride gas and takes away reaction heat. The pH value of the hot water of the converter is controlled to be 8-10, the control of the pH value is an important index for preventing and reducing corrosion of a tube array of the converter, once the tube array leaks, water absorbs hydrogen chloride to form hydrochloric acid, the converter can be corroded rapidly, and subsequent equipment is corroded, so that the effect is very serious. 1. The pH of the hot water in the converter is measured once a week or periodically by on-site sampling. 2. If the converter leaks, hydrogen chloride enters the hot water system, so that the pH value of the hot water is reduced, and the converter and other subsequent equipment are corroded. Disclosure of Invention To solve the problems set forth in the background art. The invention provides an online monitoring method for the PH value of hot water of a converter in the production of polyvinyl chloride by a calcium carbide method, which has the characteristics of reducing manpower and being capable of being monitored in real time. The invention also provides an online monitoring method for the PH value of the hot water of the converter in the production of the polyvinyl chloride by the calcium carbide method. In order to achieve the purpose, the invention provides the following technical scheme that the method for on-line monitoring of the PH value of hot water of a converter in the production of polyvinyl chloride by a calcium carbide method comprises the following steps: S1, generating chloroethylene and releasing heat under the heating and catalytic reaction of a catalyst in a converter tube, wherein hot water is circulated outside the converter tube; S2, hot water flowing through the surface of the converter tube array enters a hot water return tube, is stored in a hot water tank, and then enters a PH value on-line detector through a valve, a hot water pump and a branch of a hot water supply tube; S3, circulating cooling water enters the PH value on-line detector through a circulating cooling water feeding pipe, and then is discharged from a circulating cooling water return pipe to indirectly cool hot water entering the PH value on-line detector; s4, continuously monitoring the PH value of the hot water entering the PH value on line by a PH value on-line detector and giving an alarm when the PH value exceeds a preset value; The supporting device of converter hot water PH value on-line monitoring method in the calcium carbide process polyvinyl chloride production comprises a hot water tank, wherein a hot water return pipe is connected to the upper end of one side of the hot water tank, a steam pipe is connected to one side of the top end of the hot water tank, a hot water tank water supplementing pipe is connected to the middle of the top end of the hot water tank, a PH value on-line detector is connected to the bottom end branch of one side of the hot water tank, a circulating cooling water supply pipe is connected to the water inlet of the PH value on-line detector, a circulating cooling water return pipe is connected to the water outlet of the PH value on-line detector, a hot water supply pipe is connected to the inlet of the detection port of the PH value on-line detector, a valve is also connected to the bottom end branch of the hot water tank, and the output end of the hot water pump is connected to the branch pipe of the hot water supply pipe. The invention further discloses a water heating tank, which is correspondingly connected with water inlets of a hot water return pipe, a steam pipe and a hot water tank water supplementing pipe through valves. In the