Novel online pressure or differential pressure continuous detection system for low-temperature corrosive gas

Abstract

The invention is applied to pressure detection of dust-containing, high-temperature non-corrosive and low-temperature corrosive process gas in the field of chemical engineering or petrochemical engineering, and particularly relates to a novel online pressure or differential pressure continuous detection system for low-temperature corrosive gas. Comprising a constant-current pipeline, a self-heat-tracing pipeline, a purging pipeline, instrument design and pipe fittings, wherein the instrument design and the pipe fittings are connected in series and in parallel on the pipelines; one end of the constant flow pipeline is communicated with one end of the purging pipeline through a three-way joint I, the other end of the constant flow pipeline is respectively communicated with the measuring pipeline and the self-heat-tracing pipeline through a three-way joint II, and the other end of the self-heat-tracing pipeline is communicated with a high-temperature gas process pipeline; nitrogen or other inert gases are introduced into the isolation gas source inlet to serve as an isolation gas source, and the flow of the isolation gas source is adjusted through the upstream pressure-stabilizing constant-current regulator, so that the pressure value of the test point A of the pressure instrument is the pressure value of the sampling point B. Therefore, on-line pressure continuous measurement is achieved, the interference of air source pressure fluctuation is overcome through the upstream pressure-stabilizing constant-current regulator, and the measurement stability is guaranteed.

Description

technical field [0001] The invention is applied to the pressure detection of dust-containing, high-temperature non-corrosive, low-temperature corrosive process gases in the chemical or petrochemical field, involving the pressure, Differential pressure and liquid level detection, specifically relating to a new type of low-temperature corrosive gas online pressure or pressure difference continuous detection system. Background technique [0002] In the field of chemical industry and petrochemical industry, silicon chemical industry, titanium dioxide, phosphate compound fertilizer, sulfur recovery and other similar projects often need to deal with high temperature gas pressure or Differential pressure is tested. [0003] During normal operation, high-temperature gas has no corrosive effect on metal pipes or equipment. When the local gas temperature in equipment or pipelines drops to the gas dew point, it will cause corrosion to metal pipes or equipment. At the same time, due to...

AI Technical Summary

Problems solved by technology

[0006] First, since the rotameter can only measure the flow rate of back blowing and cannot control the flow of back blowing when blowing back to the pressure pipeline, the pressure of the measurement pipeline is the pressure of the back blowing pipeline, not the pressure of high-temperature gas that needs to be measured , so the solution of heat back blowing can only be measured intermittently and cannot be continuously measured online;

[0007] Second, if the anti-blowing pipeline needs to adjust the flow rate, it cannot use a pneumatic valve with a solenoid valve for remote control. The solenoid valve can only play a switching role, so only valves that can adjust the throttling area (such as stop valves) can be used;

[0008] Third, due to the first reason, intermittent air blowing cannot guarantee that the temperature of the pressure pipeline will not drop below the dew point temperature, so it cannot guarantee that the measurement pipeline will not be corroded;

[0009] Fourth, since the pressure of the pipeline or equipment may exceed the pressure of the gas source, it may cause the pipeline process medium to flow back into the blowback pipeline system, and even cause the entire instrument air or nitrogen system to be polluted, resulting in a safety accident;

[0010] Fifth, in theory, instrument air or other inert gases do not contain water, but due to abnormal driving or poor dehydration effect of air compressor equipment, low temperature environment, etc., the air source often contains water, so the water-containing blowback gas The source will accelerate the corrosion of the pipeline;

Images