Typical Coal Fired Thermal Power Station Application
The regenerative type air preheater (24) transfers heat from the outgoing flue gas stream to the incoming combustion air. This heat transfer process is critical to the combustion of coal, gas, and oil within the boiler. Heat transfer losses within the air preheater lead to combustion deficiencies and increased fuel costs, which can be detrimental to the profitability of the site.
Additionally,
From the incoming feedwater (28), intake air (22), and fuel requirements (14) to the cooling of water (1) and need for pollution control devices (25), the reliability of the air preheater (24) plays just as big a part in having a successful operation. The air preheater is the start and finish of the combustion process and if this shuts down then the whole system shuts down. Make sure the air pre
Air Preheater Leakage Effects
Leakage Effects and Maintaining Seals and Sealing Surfaces
Full Contact Rotor Brush Seals
If you have yet to do it, consider installing full contact rotor brush seals that will reduce leakage gaps and improve overall performance of the air preheater. Full contact rotor brush seals are less evasive to the sealing surfaces and a lot more forgiving than previous rigid full contact seals. Our installation procedures will ensure that the rotor brush seals work according to design in order to maximize leakage reduction while preventing a bottle up incident or sealing surface failure.
Sealing Surface and Rotor Alignment
The alignment of the rotor to the corresponding sealing surfaces is critical to reducing leakage. The seals can be set properly to one surface but then can show large gaps at adjacent sealing surfaces if the rotor is out of level or the sealing surfaces need to be adjusted. Have us perform an alignment assessment using the latest templates and alignment tools to reduce leakage as much as possible.
Setting or Replacing Proximity Seals
The original design rotor seals are considered proximity seals and are not supposed to make full contact as they are very rigid and will wear through corresponding sealing surfaces if set too tight. To be safe, many make the mistake of setting the seals too far away from the sealing surface, which increases leakage considerably as shown in the above performance test. Out of tolerance settings combined with irregular sealing surfaces will cause leakage rates to double or triple the contract design. If fan capacity is an issue, then most likely the air preheater seals and sealing surfaces need to be adjusted or replaced. Give us a call or an email and let our experts assist you with a leakage reduction project.
Learn More
Attention to detail is key when inspecting seals and sealing surfaces and can be vital to maximizing performance and energy savings. Make sure all of the rotor seals are set to an optimum setting to increase performance and fan capacity while reducing gas volume and pollution out of the stack.