Direct ignited Gas fired burner system on a high pressure Air Heater.

 

A particular challenge for Industrial combustion is firing into a combustion chamber or system that runs with several bars varying back-pressure. Headworx encountered such challenge and developed a high temperature air heater (max. 700 °C) specifically for such a process, using modern CFD technology to visualize temperature distribution in the air heater and more important temperature uniformity at the outlet of the air heater. Pressure losses in the system were calculated using CFD modelling, as well as the influence of secondary air on the final temperature profile at the air heater exhaust.

 

The control system included a state of the art Safety PLC with software for electronic gas to air ratio controls on the burner. The safeguarding system for the gas to air ratio has been designed according EN standards including EN 746-2, Industrial Thermo processing equipment - Part 2: Safety requirements for combustion and fuel handling systems. An analysis has been executed to define Safety Integrity Levels (SIL) of all the safeguarding functions in the system. The required action of most safety functions is to shut down the process in a safe way.

 

Due to the extreme high (varying) back pressures (0-6 bar) in the system the combustion chamber had to be designed taking the European Harmonized Pressure Equipment Directive into consideration.

 

One of the advantages of the system is a very fast response to changing back pressures in the process, without influencing the pre-set air to gas ratio for combustion. Another advantage is the very fast heat up and cool down cycle time. In order to achieve this a burner with special nozzle was developed to guarantee reliable ignition, even at high back pressures, as well as clean combustion with the lowest possible emissions over the full turn down range.

 

Having the current system available Headworx will be able to develop equipment for similar applications requiring direct gas fired air heaters, such as:

  • Combustion Research and Engine Development test stands.
  • Valve testing for aviation maintenance, repair, and overhaul (MRO) facilities.
  • Pollution control in SCR NOx and other Catalyst applications.