The QBJ indirect fired heater is an indirect heating system composed of a high pressure gas coil, a heater shell, firetube, expansion tank, exhaust stack & burner control system. The firetube burner and control system via combustion in the firetube, heats the heat media solution (normally H2O & EG). The exhaust gas are conveyed out by the exhaust stack. The heated solution transfers the heat via convection to the gas coil and thereby the gas as it flows through the coil. This indirect heating system is inherently safe in that the flame is always separated from the gas coil by a H2O / EG bath.
The firing rate of the burner is controlled in response to temperature controllers (thermostats) sensing the temperature of the outlet gas and or the H2O / EG bath. Temperature controllers may be either pneumatic or electronic. Burners may be either natural draft (65% to 70% efficient) or forced draft (75% to 85% efficient).
Gas Coils are ASME designed, fabricated (100% radiographed) and stamped for applicable service pressure and temperature.
Firetubes and heater shells are designed and fabricated as per API-12K. Heater shells are normally insulated for greater thermal efficiency.
The expansion tank is sized for 6% of the cold heater volume and provides constant containment for the solution as the heater increases and decreases in temperature. A secondary use of the expansion tank is to maintain a liquid seal above the top of the heater shell during periods of nonuse in order to prevent corrosion to the upper shell.
A low liquid level switch provides for the shutdown of the burner system in the event of a low bath level.
Standard Indirect Fired Heater Applications
- City Gate Stations Combustion
- Turbine Plants
- Dehydration Facilities
- Pressure Reduction Stations
QBJ Optional Features
- Electronic Pilot Igniter/ Reigniter
- Flame Failure Shutdown
- High Stack Temperature Shutdown
- Low Bath Level Shutdown
- Forced Draft Burners
- Electronic PLC Control Panel
- ASME Code Fuel Gas Scrubber
- Skid Mounted
- Ladder and Platform
QBJ Indirect Fired Heater Standard Features
- High Thermal Efficiency
- Expansion Section
- ASME Code Construction
- Fuel Gas Preheat Coil
- Insulation with Embossed Aluminum Jacketing
- Stainless Steel Instrument Tubing
- API 12K Construction
- Flame Arrestor
- Temperature Controller
- High Temperature Shutdown
- Stack Down Draft Diverter