A furnace draft pressure transmitter measures very small pressures in boiler, dryer and kiln combustion chambers over −1,000 … +1,000 Pa with 0.055 % accuracy. Its 4–20 mA signal controls the ID fan to keep the furnace slightly negative, preventing flame and flue-gas puff-back – following European practice under EN 12953-7, EN 12952-8 and EN 746-2.
Furnace draft pressure transmitter specifications
| Parameter | Value |
|---|---|
| Output | 4–20 mA (HART optional) |
| Accuracy | 0.055 % |
| Range | −1,000 … +1,000 Pa (can be re-ranged narrower) |
| Supply | 8 – 30 VDC |
| Max temperature | 120 °C |
| Applications | Furnace draft in boilers, dryers, kilns, incinerators |
Why measure furnace draft?
- Safety: positive furnace pressure pushes flame, smoke and CO into the operating area.
- Efficiency: excessive draft draws in cold air, raising heat loss and excess air.
- Control: hold about −20 … −50 Pa with an ID fan VFD.
Furnace pressure control with the ID fan
The furnace draft pressure transmitter feeds the furnace pressure PID, which drives the ID fan VFD; feed-forward from the FD fan lets the ID fan respond before pressure swings – see boiler fan control with VFDs.
Correct installation
- Take the tap on the furnace wall where flow is steady, away from direct flame.
- Slope impulse lines back to the furnace so condensate and dust drain; fit a purge valve.
- Vent the L port to a stable, draught-free atmosphere.
- Mount the transmitter above the tap and away from radiant heat.
Reference standards
| Standard | Scope |
|---|---|
| EN 12953-7 / EN 12952-8 | Firing systems for shell / water-tube boilers |
| EN 746-2 | Safety of industrial furnace firing systems |
| EN 50156-1 | Electrical equipment of furnaces |
| EN 60770 | Transmitter evaluation |
Related products
- Differential pressure sensor
- Low DP transmitter CST-MDP
- 10 DP transmitter applications
- Yokogawa EJA pressure transmitters
Contact ISE
EQUIPMENT INDUSTRIAL SOLUTION CO., LTD (ISE) – Ho Chi Minh City, Vietnam.
Contact us: Sales +84 909 617 185 – Technical +84 979 117 185 – Email: [email protected]
