Instrument air interlocking air supply device

Abstract

An instrument air interlocking air supply device belongs to the technical field of air supply devices. The device consists of a first pressure gauge, a first stop valve, a second pressure gauge, a check valve, a second stop valve, a ball valve and an instrument air buffer tank which are sequentially arranged on an air supply pipeline of the electrolytic bath, the second stop valve and the check valve are arranged in parallel, the parallel end is connected to the air supply pipeline behind the second pressure gauge, and the other parallel end is connected with the instrument air buffer tank through the ball valve. When the pressure of the first pressure gauge is smaller than 0.400 Mpa, SIS interlocking is triggered, the first stop valve is automatically closed, the second stop valve is automatically opened, and pipe network air supply is switched into instrument air buffer tank air supply. According to the utility model, the condition that the electrolytic cell cannot normally circulate due to insufficient air pressure of the instrument can be effectively prevented, the generation of reverse current is inhibited, the electrolytic cell is prevented from being corroded by the reverse current, the service life of the electrolytic cell is protected, and the production is more stable and reliable.

Description

Technical Field

[0001] The utility model belongs to the technical field of air supply devices, and specifically relates to an instrument air interlock air supply device, which can solve the problem that the electrolytic cell cannot circulate normally because the automatic valve cannot operate when the electrolytic device stops due to abnormal low instrument air pressure. Background Art

[0002] After the power outage of the ion membrane electrolyzer of the caustic soda plant, the cathode and anode need to be circulated, and the gas phase chamber is filled with caustic soda and refined brine and the chlorine-containing brine is replaced, respectively, to inhibit the formation of reverse current in the electrolyzer, ensure that the electrolyzer will not be corroded by the reverse current, increase the voltage and power consumption and service life of the electrolyzer, and thus protect the electrolyzer. However, when the electrolyzer triggers the SIS (safety instrument system) interlock shutdown due to the instrument air pressure being less than 0.400MPa, the automatic valves of the inlet and outlet instruments of the electrolyzer cannot operate normally, resulting in the inability to carry out normal circulation of the electrolyzer, which will form a reverse current and corrode the electrolyzer, thereby affecting the service life of the electrolyzer. Utility Model Content

[0003] The utility model is to solve the above problems and provides an instrument air interlock gas supply device, which can solve the problem that the electrolytic cell cannot circulate normally due to the instrument air pressure being lower than the interlock value and the interlock parking.

[0004] In order to achieve the above-mentioned purpose, the utility model discloses an instrument air interlock gas supply device, which is composed of a first pressure gauge 6, a first shut-off valve 2, a second pressure gauge 7, a check valve 4, a second shut-off valve 3, a ball valve 5 and an instrument air buffer tank 1 which are sequentially arranged on the electrolytic cell gas supply pipeline; the second shut-off valve 3 and the check valve 4 are arranged in parallel, one end of which is connected in parallel to the gas supply pipeline behind the second pressure gauge 7, and the other end of which is connected in parallel to the instrument air buffer tank 1 via the ball valve 5.

[0005] When the pressure of the first pressure gauge 6 is less than 0.400 MPa, the SIS (Safety Instrument System) interlock is triggered, the first shut-off valve 2 is automatically closed, the second shut-off valve 3 is automatically opened, and the gas supply from the pipeline network is switched to the instrument air buffer tank 1 to supply gas to the electrolytic cell device, ensuring the normal circulation of electrolysis.

[0006] The beneficial effects of the utility model are: it can effectively prevent the situation that the electrolytic cell cannot circulate normally due to insufficient instrument air pressure, inhibit the generation of reverse current, ensure that the electrolytic cell will not be corroded by the reverse current, protect the service life of the electrolytic cell, and make production more stable and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a schematic diagram of the utility model;

[0008] In the figure: on the gas supply pipeline of the electrolytic cell, a first pressure gauge 6, a first shut-off valve 2 and a second pressure gauge 7, a second shut-off valve 3 and a check valve 4 in parallel are arranged in sequence; one end of the second shut-off valve 3 and the check valve 4 are connected in parallel and connected to the pipeline behind the second pressure gauge 7, and the other end is connected in parallel and connected to the instrument air buffer tank 1 through a ball valve 5.

[0009] The first shut-off valve 2 (specification model: DN80 pneumatic ball valve shut-off valve; material: 304 / PTFE), the second shut-off valve 3 (specification model: DN80 pneumatic ball valve shut-off valve; material: 304 / PTFE), the check valve 4 (specification model: DN80 swing check valve; material: 304 / PTFE), the ball valve 5 (specification model: DN80 manual ball valve; material: 304 / PTFE), the first pressure gauge 6 and the second pressure gauge 7 (remote pressure gauge / pressure transmitter).

[0010] There is SIS interlocking logic between the first shut-off valve 2 , the second shut-off valve 3 and the first pressure gauge 6 .

[0011] The check valve 4 ensures that when the pipeline network pressure is lower than the system operating pressure, the instrument air buffer tank 1 does not release pressure to the pipeline network.

[0012] The ball valve 5 is normally open under normal conditions and is closed under maintenance to isolate the system. DETAILED DESCRIPTION

[0013] Example 1

[0014] During normal operation, the first shut-off valve 2 is opened, the second shut-off valve 3 is closed, and the ball valve 5 is opened. The instrument air is supplied to the electrolytic cell device normally through the pipeline network via the first shut-off valve 2. At the same time, air is supplied to the instrument air buffer tank 1 via the check valve 4 and the ball valve 5, so that the instrument air buffer tank 1 maintains the same pressure as the pipeline network.

[0015] If there is a problem with the instrument air device of the public engineering project, resulting in the interruption of instrument air supply or pressure fluctuation of the instrument air network, the first pressure gauge 6 triggers the SIS interlock when the pressure is ≤0.400Mpa, the first shut-off valve 2 is automatically closed, and the second shut-off valve 3 is automatically opened. At this time, the device of the utility model is disconnected from the instrument air network, and the instrument air buffer tank 1 (volume: 50m 3; Pressure: 0.700MPa) The electrolyzer device is supplied with air through the ball valve 5 and the second shut-off valve 3. The second pressure gauge 7 monitors the pressure of the instrument air buffer tank 1 at any time. The process personnel judge the processing time after the interlock is triggered. At this time, the instrument air supply device completes the work. When the instrument air of the public engineering device resumes normal supply, the first pressure gauge 6 shows > 0.400MPa. The process personnel press the reset button on the auxiliary console. At this time, the first shut-off valve 2 opens, the second shut-off valve 3 closes, and the instrument air resumes normal supply to the electrolyzer device through the instrument air pipeline network. At the same time, the pressure of the instrument air buffer tank 1 is supplemented to the same pressure as the pipeline network through the check valve 4 and the ball valve 5 to ensure that it can be put into use normally at the next interlock.

Claims

1. An instrument air interlock supply device, characterized in that: The invention comprises a first pressure gauge (6), a first shut-off valve (2), a second pressure gauge (7), a check valve (4), a second shut-off valve (3), a ball valve (5) and an instrument air buffer tank (1) which are sequentially arranged on the gas supply pipeline of the electrolytic cell; the second shut-off valve (3) and the check valve (4) are arranged in parallel, one end of which is connected to the gas supply pipeline behind the second pressure gauge (7), and the other end of which is connected to the instrument air buffer tank (1) via the ball valve (5); and SIS interlocking logic exists between the first shut-off valve (2), the second shut-off valve (3) and the first pressure gauge (6).

2. An instrument air interlock supply device according to claim 1, characterized in that: The first shut-off valve (2) is a DN80 pneumatic ball shut-off valve, the second shut-off valve (3) is a DN80 pneumatic ball shut-off valve, the check valve (4) is a DN80 swing check valve, the ball valve (5) is a DN80 manual ball valve, and the first pressure gauge (6) and the second pressure gauge (7) are air pressure transmitters.

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