Positive Pressure Explosion Proof Cabinet & Isolated Explosion Proof
Note: All our equipment supports custom explosion proof series.
It is designed and examined according to the national standard GB3836.5-2004 Electrical equipments positive pressure”P” used in explosive gas environment. Can be widely used in petroleum, chemical industry, medicine etc. in which dangerous area with explosive gas and dust.
Ex-mark is ExpxdmbllCT4.
The PXK bring the clean and security of compressed air in positive pressure cavity by intelligent control system matching pressure control system of explosion-proof control box and to be a micro-positive pressure to prevent the dangerous gases, dust in,which reached to the purpose of explosion-proof. This product with the function of intelligent centralized control, LCD text display, automatic ventilation, automatic delay power-up, air supply for pressure loss, fault alarm and automatically cut off power supply in danger, etc
Positive pressure cabinet is composed of positive pressure cavity and control cavity;Positive pressure cavity is used for installing various of instrument or electronics which with non-explosion-proof.The control cavity has explosion-proof control box and pressure control system.The case material of positive pressure cabinet with 2~3mm Cold rolled steel sheet welding and the Air-duct with galvanized steel pipe;Adopt bulkhead connector and tightening device for in&out of the cable.There is a glass display in the front of door and display the information of instrument and indicator light.
1. PXK value >280Pa,Automatic vent
2. 50pa <PXK value <80pa, automatic alarm
3. PXK value<50Pa,Automatically power off
The operation principle please refer to picture
Please press the “Start Button” after outside voltage 220V AC in explosion-proof control box; Open air-intake casing by magnetic valve 4 excitation, the compressed air come into the positive pressure cavity by filtering and decompression;the dangerous gas of positive pressure cavity is discharged by exhaust valve 8;When the dangerous gas of positive pressure cavity reached to safety value,the ventilation will be finished as well as interlocking contact closed automatically.In that case,electric appliance& instrument in positive pressure cavity can start to work.
The adjustment for positive pressure values
Adjust the bottom of positive pressure value regulating handle of one-way throttle valve,PXK value will be higher by Clockwise,on the contrary,be lower.It is reasonable to adjust the PXK value to be 250Pa,if the pressure is low and can not be reached to this fine pressure,please kindly check whether the air inlet valve is open totally or not,and if the positive pressure chamber is sealed with the outside and so on.
Interlock Function Selection
PXK used in the dangerous area 1,if PXK value<50Pa,interlocking contact must be off;If operating in the dangerous area 2, PXK value < 50Pa, interlocking contact can be open;But you must deal with in time and ensure the pressure > 50Pa, this function by DIP SWITCH U2 the 3rd to adjust,which in the condition of up interlocking contact off, below interlocking contact do not disconnect and to operate in off-state.
PXK Constant-temperature Cooling System
It auto controls the cooling water into the internal heat exchanger of system to take the heat of PXK away. It can make sure the internal system in the situation of constant-temperature and keep every part safe.
Isolated explosion proof (EXdIIBT4)
1. Electrical cabinet (adopt Isolated explosion proof )
A. Separate wiring chamber.
B. Heating power >7.5KW, with independent heat dissipation aluminum fins explosion-proof cabinet.
C. Electric cabinet adopts whole aluminum mold.
D. Equipped with explosion-proof mouse, to operate 7-inch touch screen (optional Siemens explosion-proof touch screen – 7 inch, 12 inch).
A. Using isolated explosion proof.
B. Adopt Terminal block packaging process (Intrinsically safe)
3. Circulating fan
A. Using isolated explosion proof
B. Aluminum fin
4. Circulating pump adopts isolated explosion proof motor
5. Heater adopts flameproof type (heating power per unit area<3W)
6. Temp. sensor adopts flameproof type
7. Pressure sensor adopts flameproof type
8. Various protection areas are installed in flameproof boxes