Natural gas analyzer gas path valve control system

The topics of chromatographic column flow rate, constant flow and pressure mode of chromatographic column, split ratio, injection port pressure, various gases required for the detector to achieve detection effect, etc., have not yet delved into the basic individualvalveThe component, and it is precisely this component that plays a natural yet extremely important role in the control of the pneumatic system.

Natural gas analyzer gas path valve control system

Today, with the development of gas chromatography equipment, major manufacturers have demonstrated their unique skills, and the design of gas flow paths has become very mature.

The common classification of designs in the current market isMechanical control flow pathandElectronic control flow pathThere are two main categories, and electronic flow paths are becoming increasingly mainstream configurations.

Further subdividing,Mechanical pneumatic controlInside, there is an injection port and a carrier gas inletMechanical stabilizing valve, used to control the total flow rateSteady flow valve, used to control column head pressureback pressure valveThe detector'spressure regulating valveandneedle valveWait.

In terms of electronic controlofpressure sensor，flow sensor，proportional valveWait.

You can see it all, at the end of the day, whether it's these valves or sensor proportional valves, they silently hold onto the various lifelines of the gas path in the gas-phase system. It's not an exaggeration to say that they are the heroes of the entire system.

So let's take a look at the "daily life" of the valves together with everyone in several parts!

In this issue, we willMechanical control flow systemStart.

pressure regulating valve

Mechanical valves includePressure regulator valve, flow regulator valve, back pressure valve, and needle valve.

Natural gas analyzer gas path valve control system-pressure regulating valve.

From an external perspective, the valve body hasGas inletandExportTwo interfaces, usually requiring a three-way connection at the outlet to display pressureheader.

The function of a pressure regulator valve is to maintain stable pressure in the part connected to the rear end of the valve outlet.

Voltage stabilization principle

When there is a fluctuation in the input pressure at the front end, the stabilizing valve can adjust its internal structure to prevent the output pressure from being affected by this fluctuation;When there is a fluctuation in the front pressure, the valve seat maintains the stability of the output pressure by adjusting the size of the gap at the gas inlet.

For example, when we discoverThe retention time is not rightWhen it comes to this, the first thing to check is whether the pressure entering the gas cylinder is normal;

For exampleCan't light it upWe need to check if the front-end input pressure of hydrogen and air is normal.

The significance of stabilizing valve

Gas passes through pipelinesThe * valve components connected to the instrument must be pressure regulating valves in order to provide a stable pressure to the backend system.

Specifically for each component's air circuit:

Inject air into the pipelineThe stabilizing valve provides a stable pressure for the back-end injection port to ensure the stability of the total flow rate of the injection port, thereby ensuring a constant column head pressure or constant column flow rate (specifically how to ensure this, we will introduce the stabilizing valve and back pressure valve in detail later). As we all know, the role of column flow rate in the instrument system is crucial and will not be mentioned here.

Detector gas controlThe performance of the detector is also important. As we know, the gas control display of the detector is flow rate. In actual mechanical gas circuit design, the output flow rate to the detector end is regulated by a regulator valve and a needle valve, and the flow rate of each gas in the detector needs to be measured by a flowmeter