The main purpose of the special gas application control system is to provide high-purity electronic special gas for the safety of industrial process terminal gas points. The entire system includes numerous modules, covering the entire flow path from gas source to gas diversion to terminal gas points.

The user unit has two major requirements for the use of special gas, one of which is to ensure pressure and purity. The pressure in the special gas control system is achieved through a pressure regulating valve, and purity can be achieved through the high airtightness of the system to avoid external pollution and filter particles in the gas through a filter.

The second main requirement is safety. Hazardous gases such as flammable and explosive gases, toxic gases, and corrosive gases are all classified as special gases. Therefore, the risk of special gas system engineering is relatively high, and supporting safety facilities need to be considered in the design, installation, and operation.

Today we will mainly learn about the safety linkage devices in the special gas application control system?

01 Emergency stop button

The emergency stop button is used to remotely close the pneumatic valve of the on-site gas supply equipment.

When the leakage alarm reaches the second stage alarm, the staff can remotely manually shut down the gas supply equipment and promptly close the pneumatic valve of the gas supply equipment.

02 Gas detector

Gas detectors are mainly used for continuous and uninterrupted sampling and analysis of gas supply equipment to determine whether there is gas leakage in the equipment.

When the detector is working normally, the sampling flow rate of the detector reaches 500mL/min.

For heated gases, a gas heating unit needs to be installed to achieve auxiliary heating effect.

03 Alarm light

The alarm indicator light is mainly used to indicate the on-site alarm situation, consisting of an alarm light and a buzzer.

The alarm indicator light is usually a tower type alarm light. When the leakage alarm reaches a certain alarm line, the alarm light will turn yellow and the buzzer will start; When the leakage alarm reaches the second alarm line, the alarm light will turn red and the buzzer will start.

The alarm light requires 24VDC power, and the buzzer sound needs to reach 80 decibels or higher.

04 Spray Head

The glass bulb of the glass ball sprinkler head is filled with an organic solution with a high coefficient of thermal expansion. When a fire occurs, the temperature of the organic solution increases and expands until the glass body breaks and the seal loses support, then it is washed away by the water flow and begins to spray water.

The main function of the sprinkler head in the gas holder is to cool down the steel cylinder and avoid secondary accidents.

05 UV/IR flame detector

UV/IR can detect both UV and IR light segments in flames. After detecting both UV and IR light segments simultaneously, the detector will send a signal to the control system and trigger linkage.

Due to the presence of both UV and IR light segments in flames, UV/IR detectors can effectively avoid false alarms caused by other separate UV or IR sources.

06 Overcurrent protection switch (EFS)

The overcurrent protection switch can sense abnormal changes in gas flow rate. When the gas flow rate is greater or less than the set point, the overcurrent protection switch sends a signal to the control system and triggers linkage. The setting point of the overcurrent protection switch cannot be adjusted on site

07 Negative pressure gauge/negative pressure switch

Negative pressure gauge/Negative pressure can measure the negative pressure value inside the gas cabinet, ensuring that the equipment's exhaust volume meets the design requirements and improving operational safety.

The negative pressure switch can send a signal to the control system and trigger linkage when the negative pressure value inside the equipment is lower than the set value.

08 PLC control

The PLC control system has strong reliability, and all signals will be transmitted to the PLC system for processing and then transmitted to the human-machine interface. The PLC can complete the signal transmission and control of all terminal devices.