Explosion proof thermal oil circulation device

All water-cooled models in this sample book can be designated as EXPXdmb I BT4 or EXPXdmb I Ct4

It is designed, manufactured, and inspected according to the national standard GB3836.5-2004 (positive pressure type "P" for electrical equipment used in explosive gas environments). It can be widely used in hazardous areas with explosive gases and dust, such as petroleum, chemical, and pharmaceutical industries. The explosion-proof mark is Expxdmb ICT4. Explosion proof certificate number: GYB091118.

The positive pressure cabinet matches the intelligent control system inside the explosion-proof control box with the pressure control system to introduce clean and safe compressed air into the positive pressure chamber, creating a slight positive pressure inside the chamber and preventing the entry of hazardous gases and dust from the outside, achieving the purpose of explosion prevention. This product has functions such as intelligent centralized control, LCD text display, automatic ventilation, delayed automatic power supply, pressure relief, fault alarm, and automatic power-off in case of danger.

Structural Overview

The positive pressure cabinet consists of a positive pressure chamber and a control chamber. The positive pressure chamber is used to install various non explosion proof instruments or electrical appliances, while the control chamber consists of an explosion-proof control box and a pressure control system. The outer shell of the positive pressure cabinet is welded with 2-3mm cold-rolled steel plates, the ventilation pipes are made of galvanized steel pipes, and the incoming and outgoing cables are connected with conduit joints and cable entry clamping devices. The front door is equipped with a glass display window, which displays instruments and indicator lights. .

safety indicators

a、 Automatic exhaust when the positive pressure value inside the cabinet is greater than 280Pa

b、 When the positive pressure value inside the cabinet is less than 80Pa and greater than 50Pa, an automatic alarm will be triggered

C、 If the positive pressure value inside the cabinet is less than 50Pa, the power will be automatically cut off

working principle

The working principle of the positive pressure cabinet is shown in the left figure. After the external 220 volt current is introduced into the explosion-proof control box, the "start button" is pressed, and the electromagnetic threshold 4 is excited to open the intake pipeline. Compressed air is filtered and depressurized before entering the positive pressure chamber. The dangerous gas in the positive pressure chamber is discharged from the positive pressure chamber through exhaust. When the dangerous gas in the positive pressure chamber is replaced to safety, the ventilation is completed and the interlocking contacts are automatically closed. At this time, the electrical appliances and instruments in the positive pressure chamber can work.

Adjustment of positive pressure value

Adjust the handle for adjusting the positive pressure value at the lower end of the one-way throttle, turn it clockwise to increase the positive pressure value, and vice versa to decrease the positive pressure value. It is advisable to adjust the positive pressure value to 250Pa. If the pressure is too low to be adjusted to this pressure, check whether the intake is fully open and whether the positive pressure chamber is sealed from the outside.

Interlocking function selection

When the positive pressure cabinet is used in hazardous areas in Zone 1, if the positive pressure value is less than 50Pa, the interlocking contact must be disconnected; If used in hazardous areas in Zone 2, if the positive pressure value is less than 50Pa, the interlocking contacts can be continuously opened; But it is necessary to handle it in a timely manner to ensure that the pressure is greater than 50Pa. This function is adjusted by the third position of the shift switch U2. The third position is disconnected at the upper lock contact and continuously opens at the lower lock contact. When shifting, it needs to be done in the disconnected state.

Positive pressure explosion-proofCabinet constant temperature cooling system

Adopting water cooling method, the cooling water is automatically controlled to enter the internal air conditioning heat exchanger of the system, taking away the heat inside the positive pressure cabinet, ensuring that the internal of the positive pressure system is in a constant temperature state, and ensuring the safety of internal components.

Application field

Applied in environments with flammable and explosive gases