Single-cell pressure relief device of ionic membrane electrolytic cell

Abstract

The utility model discloses a single cell pressure relief device of an ionic membrane electrolytic cell, which relates to the technical field of chlor-alkali and comprises an electrolytic cell, an anode outlet pipeline, a cathode outlet pipeline, an anode pressure relief pipeline and a cathode pressure relief pipeline, an anode pressure relief valve is arranged on the anode pressure relief pipeline, and a cathode pressure relief valve is arranged on the cathode pressure relief pipeline. One end of the first communicating pipe is connected with the front end of the anode pressure relief valve of the anode pressure relief pipeline, the other end of the first communicating pipe is connected with the anode emptying tank, one end of the second communicating pipe is connected with the front end of the cathode pressure relief valve of the cathode pressure relief pipeline, and the other end of the second communicating pipe is connected with the cathode liquid tank. The first communicating pipe and the second communicating pipe are provided with the first hand valve and the second hand valve respectively, the pressure difference between the cathode and the anode is monitored through the U-shaped differential pressure gauge, an operator can manually adjust the opening degree of the pressure relief channel, and accurate control over the pressure difference is achieved. The device is simple in structure and flexible to operate, effectively reduces differential pressure fluctuation, protects the ionic membrane and the electrolytic bath, and improves the stability and safety of the system.

Description

TECHNICAL FIELD

[0001] The utility model relates to chlor alkali technical field especially relates to a single tank pressure relief device of ion exchange membrane electrolytic cell. BACKGROUND

[0002] Ion exchange membrane electrolytic cell has important position in chemical production, and the ion exchange membrane operation process requires that the anode and cathode pressure difference is kept at 4KPa, (normal production in the anode pressure control 24KPa, the cathode pressure is controlled at 28KPa) the low low alarm value of pressure difference is 1.5KPa, the low alarm value is 2KPa, the high alarm value is 4.5KPa, the high high alarm value is 6.0KPa, if the positive pressure difference is too large, then it is easy to cause the anode plate deformation, unit tank leakage. If the negative pressure difference is too large, due to the electrolytic cell anode and cathode plate, the anode plate is rougher than the cathode plate, then it is easy to cause the ion exchange membrane wear, appear pinhole, even tear the ion exchange membrane, cause the safety production accident.

[0003] After single tank parking, the system is cut out first, so that the single tank is completely isolated from the system. After the single tank is cut out from the system, the electrolytic cell single tank cathode pressure relief valve and the anode pressure relief valve are manually opened and closed for pressure relief on site, which requires the operator to go to the site and manually adjust the opening degree of the pressure relief valve through the control cabinet, increasing the operation complexity and work intensity, and easily causing rapid pressure fluctuation during pressure relief operation, resulting in large pressure difference. UTILITARY MODEL

[0004] In order to solve the above technical problems, the utility model provides a single tank pressure relief device of ion exchange membrane electrolytic cell, adopts the following technical scheme:

[0005] A single tank pressure relief device of ion exchange membrane electrolytic cell, comprising an electrolytic cell and an anode outlet pipe connected with an anode outlet of the electrolytic cell, an anode liquid main pipe valve is installed on the anode outlet pipe, the anode outlet pipe is also connected with an anode pressure relief pipeline, the anode pressure relief pipeline is provided with an anode pressure relief valve along the pipeline, and the anode pressure relief pipeline leads to an anode emptying tank; a cathode outlet pipe is connected with a cathode outlet of the electrolytic cell, a cathode liquid main pipe valve is arranged on the cathode outlet pipe, the cathode outlet pipe is connected with a cathode pressure relief pipeline, and a cathode pressure relief valve is arranged on the cathode pressure relief pipeline and leads to a cathode liquid tank;

[0006] The device further comprises a first communication pipe, one end of which is connected to the anode pressure relief pipeline before the anode pressure relief valve, and the other end is connected to the anode emptying tank; a second communication pipe, one end of which is connected to the cathode pressure relief pipeline before the cathode pressure relief valve, and the other end is connected to the cathode liquid tank; the pipe diameter of the first communication pipe and the second communication pipe is smaller than that of the anode pressure relief pipeline, and the pipe diameter of the second communication pipe is smaller than that of the cathode pressure relief pipeline; a first hand valve is arranged on the pipeline of the first communication pipe, and a second hand valve is arranged on the pipeline of the second communication pipe.

[0007] Further, the pipe diameter specifications of the first communication pipe and the second communication pipe are both DN25.

[0008] Further, the valve types of the first hand valve and the second hand valve are all ball valves.

[0009] Further, the device further comprises a U-shaped differential pressure gauge, one end of the U-shaped differential pressure gauge being connected to a pipeline upstream of the first hand valve on the first communication pipe, and the other end being connected to a pipeline upstream of the second hand valve on the second communication pipe.

[0010] The utility model discloses a small-diameter communication pipe and hand-operated regulating valve, realize the fine control of pressure relief process, eliminate the pressure fluctuation caused by large-diameter valve, effectively improve the stability and safety of pressure regulation, avoid the problems such as anode plate deformation, single tank leakage or ion membrane tearing, optimize the operation flexibility and operation reliability of system, and be applicable to the ion membrane electrolytic cell device needing high-precision anode-cathode pressure difference control, especially in the application scene of optimizing single tank pressure relief system in chlor-alkali industry field. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 It is the single tank pressure relief device of ion membrane electrolytic cell in the prior art;

[0012] Figure 2 It is the single tank pressure relief device of membrane electrolytic cell in the utility model embodiment 1;

[0013] Figure 3 It is the single tank pressure relief device of membrane electrolytic cell in the utility model embodiment 2.

[0014] Wherein, the figure mark: 1, electrolytic cell;2, anode outlet pipeline;201, anode liquid main valve;202, anode pressure relief valve;203, anode emptying tank;204, anode pressure transmitter;205, first communication pipe;206, first hand valve;3, cathode outlet pipeline;301, cathode liquid main valve;302, cathode pressure relief valve;303, cathode liquid tank;304, cathode pressure transmitter;305, second communication pipe;306, second hand valve;4, PID controller;5, U-shaped differential pressure gauge. DETAILED DESCRIPTION

[0015] Below, will combine the figure in the utility model embodiment, the technology in the embodiment of the utility model is described clearly and completely;Obviously, the described embodiment is only a part of the embodiment of the utility model, not all the embodiment;Based on the embodiment in the utility model, all other embodiments obtained by the person skilled in the art without making creative labor should belong to the protection scope of the utility model.It needs to be explained that, in the case of no conflict, the embodiment in the utility model and the features in the embodiment can be combined mutually.

[0016] The single Woody Company BM2.7 type electrolytic cell has 196 unit cells, which are installed on two cell racks, 98 unit cells on each cell rack. Each unit cell is composed of a cathode half-cell, an anode half-cell, an ion membrane and a sealing system. The cathode half-cell, the anode half-cell and the ion membrane are tightly sealed into a whole by the sealing system to form an independent electrolytic cell structure. The half-cell contains electrodes, the anode is made of titanium, and the cathode is made of nickel. The electrodes are connected to the current conducting part and the support plate through continuous laser welding, and then connected to the half-shell. The ion membrane is installed between the anode and cathode net of the anode and cathode half-cell and closely adheres to the net electrode. Refer to Figure 1 In the prior art, the electrolytic cell single cell pressure relief device includes an electrolytic cell 1 and an anode outlet of the electrolytic cell connected to an anode outlet pipeline 2. An anode liquid main valve 201 is installed on the anode outlet pipeline 2 to control the flow of anode liquid from the electrolytic cell 1 to the anode liquid main pipe. The anode outlet pipeline 2 is also connected to an anode pressure relief pipeline (pipe diameter specification DN150). The anode pressure relief pipeline is provided with an anode pressure relief valve 202 along the pipeline. The end of the anode pressure relief pipeline leads to an anode discharge tank 203 for discharging the liquid and gas on the anode side to the anode discharge tank 203 for subsequent treatment or storage during the pressure relief operation. On the contrary, the cathode outlet of the electrolytic cell 1 is connected to a cathode outlet pipeline 3. A cathode liquid main valve 301 is arranged on the cathode outlet pipeline 3 near the electrolytic cell 1 to control the outflow of the cathode liquid. The cathode outlet pipeline 3 is connected to a cathode pressure relief pipeline (pipe diameter specification DN150). The cathode pressure relief pipeline is provided with a cathode pressure relief valve 302. The end of the cathode pressure relief pipeline leads to a cathode liquid tank 303 to make the liquid and gas on the cathode side flow into the cathode liquid tank 303 during the pressure relief process.

[0017] The anode and cathode pressure relief valves are both DCS controlled regulating valves. The anode and cathode pressures and pressure difference are monitored in real time by an anode pressure transmitter 204 and a cathode pressure transmitter 304. The opening degree of the anode and cathode pressure relief valves is controlled by a PID controller to ensure the pressure difference during pressure relief. However, the opening degree of the anode and cathode pressure relief valves needs to be controlled on site during single cell shutdown or liquid discharge, which cannot be controlled by DCS. Since the anode and cathode pressure relief valves are electrically controlled regulating valves, the opening degree of the valves needs to be controlled by an operator through a control cabinet. In addition, the number of electrolytic cell unit cells is large, and the pressure difference fluctuation is prone to occur during on-site operation, which may cause damage to the ion membrane and the electrolytic cell. Especially during single cell shutdown or liquid discharge, frequent pressure difference fluctuation may seriously affect the safety of the ion membrane and the electrolytic cell.

[0018] Refer to Figure 2In order to solve the above problems, the single-tank pressure relief device for ion-exchange membrane electrolyzer provided by the embodiment comprises a first communication pipe 205, one end of which is connected to the anode pressure relief pipe line before the anode pressure relief valve 202, and the other end of which is connected to the anode emptying tank 203; and a second communication pipe 205, one end of which is connected to the cathode pressure relief pipe line before the cathode pressure relief valve 302, and the other end of which is connected to the cathode liquid tank. The pipe diameter of the first communication pipe 205 and the second communication pipe 205 is smaller than the pipe diameter of the anode pressure relief pipe line and the cathode pressure relief pipe line. The first communication pipe 205 and the second communication pipe 205 are used as pressure relief branch pipes, and a first hand valve 206 and a second hand valve 306 are arranged on the pipe lines of the first communication pipe 205 and the second communication pipe 205 respectively, for adjusting the opening of the pressure relief branch pipes on site, so as to realize accurate control of the anode pressure and the cathode pressure. Since the communication pipes with small pipe diameters can more accurately control the flow of fluid, the flow change of the anode liquid and the cathode liquid is crucial for pressure balance and pressure difference control in the pressure relief process of the ion-exchange membrane electrolyzer. The small pipe diameter means that the flow of fluid through the communication pipes is relatively small under the same pressure difference, which enables the operator to more finely adjust the pressure balance between the anode side and the cathode side.

[0019] Preferably, the pipe diameter specifications of the first communication pipe 205 and the second communication pipe 205 are both DN25.

[0020] Preferably, the valve types of the first hand valve 206 and the second hand valve 306 are both ball valves.

[0021] Reference Figure 3 Preferably, the embodiment further comprises a U-shaped differential pressure gauge 5, one end of which is connected to the pipe line upstream of the first hand valve 206 on the first communication pipe 205, and the other end of which is connected to the pipe line upstream of the second hand valve 306 on the second communication pipe 205. Through the U-shaped differential pressure gauge 5, the operator can directly read the anode-cathode pressure difference, quickly respond to real-time data on site, and accurately control the pressure difference by adjusting the first hand valve 206 and the second hand valve 306, so as to ensure that the anode-cathode pressure difference is maintained within the target range (e.g. 4KPa) during pressure relief.

[0022] Working principle of the embodiment:

[0023] When the electrolytic cell is single tank shutdown and pressure relief, the DCS controls the anode liquid main valve 201 and the cathode liquid main valve 301 to be closed, at this time, the operator can manually adjust the first hand valve 206 and the second hand valve 306, through the first communication pipe 205 and the second communication pipe 305, to release the pressure of the anode side and the cathode side through the small diameter pressure relief pipeline. Because the diameter of the communication pipe is small (such as DN25), the pressure relief flow is small and stable, which can realize more fine pressure difference adjustment and effectively reduce the pressure difference fluctuation. The U-shaped differential pressure gauge 5 is used to monitor the pressure difference between the anode and the cathode pressure relief pipeline, and the operator can manually adjust the hand valve opening degree according to the reading on site, accurately control the pressure difference, and ensure that it is stable in the target range.

Claims

1. An ion-exchange membrane electrolyzer single-tank pressure relief device, comprising an electrolyzer and an anode outlet of the electrolyzer connected to an anode outlet pipeline, an anode liquid main valve being installed on the anode outlet pipeline, the anode outlet pipeline being further connected to an anode pressure relief pipeline, the anode pressure relief pipeline being provided with an anode pressure relief valve along the pipeline, the anode pressure relief pipeline leading to an anode emptying tank, a cathode outlet of the electrolyzer being connected to a cathode outlet pipeline, a cathode liquid main valve being provided on the cathode outlet pipeline, the cathode outlet pipeline being connected to a cathode pressure relief pipeline, a cathode pressure relief valve being installed on the cathode pressure relief pipeline, a terminal end of the cathode pressure relief pipeline leading to a cathode liquid tank, characterized in that, The device further comprises a first communication pipe, one end of which is connected to the anode pressure relief pipe line before the anode pressure relief valve, and the other end of which is connected to the anode emptying tank; a second communication pipe, one end of which is connected to the cathode pressure relief pipe line before the cathode pressure relief valve, and the other end of which is connected to the cathode liquid tank; the pipe diameter of the first communication pipe and the second communication pipe is smaller than the pipe diameter of the anode pressure relief pipe line, and the pipe diameter of the second communication pipe is smaller than the pipe diameter of the cathode pressure relief pipe line; a first hand valve is arranged on the pipe line of the first communication pipe, and a second hand valve is arranged on the pipe line of the second communication pipe.

2. The single-cell pressure relief device for an ion-exchange membrane electrolyzer according to claim 1, characterized by The pipe diameter specifications of the first communication pipe and the second communication pipe are both DN25.

3. The single-cell pressure relief device for an ion-exchange membrane electrolyzer according to claim 1, characterized by The valve types of the first hand valve and the second hand valve are both ball valves.

4. The single-cell pressure relief device for an ion-exchange membrane electrolyzer according to claim 1, characterized by The device further comprises a U-shaped differential pressure gauge, one end of which is connected to the pipe line upstream of the first hand valve of the first communication pipe, and the other end of which is connected to the pipe line upstream of the second hand valve of the second communication pipe.

Images