Pyroflex SRT

Stepped grate firing system 850 to 10000 kW

The stepped grate firing system is parti­cu­larly suited to the combustion of wood fuels with a high water content of up to 60% and an ash content of 10%. These condi­tions allow the flexible use of inexpensive, undried fuels such as forest wood chips, green cuttings, bark, wood from lands­caping, short-rotation woody crops and mature timber. The wood-burning system Pyroflex SRT with stepped grate firing system is designed for conti­nuous operation of up to 8000 hours per year.

Stepped grate firing system SRT

Designed for conti­nuous operation


Fuels:
Wood from lands­caping
Bark
Green cuttings
Mature timber
Short-rotation woody crops
Special fuels

The Pyroflex SRT is parti­cu­larly suited to the combustion of wood fuels with a high water and ash content. These condi­tions allow the flexible use of inexpensive, undried fuels.

Flue gas recir­cu­lation “over” and “under” the grate

The flue gas is drawn into the exhaust line and reintro­duced to the combustion chambers “over” or “under” the grate with a fan. This decreases the flame tempe­rature and reduces nitrous oxides. The efficiency of the system is increased as a result since a lower residual oxygen content remains in the flue gas, even in the case of dry fuels.

For the flue gas recir­cu­lation “under” the grate, the recir­cu­lated flue gas is mixed with the primary air in mixing chambers and then reintro­duced under the grate. The flue gas recir­cu­lation “under” the grate also results in more complete combustion and prevents slag formation on the grate.

Minimal life cycle costs

We place the utmost impor­tance on durability and a long lifespan for our systems. This is achieved by using robust system components. Solid steel construction and the use of high-quality refractory material guarantee reliable system availa­bility for many years. Minimal power consumption in all load states of the system is ensured by frequency-controlled screws, grate drives and flue gas recir­cu­lation.

Equipment and access­ories

Measu­re­ments in the primary air and recir­cu­lation air

The flow rates of the primary and recir­cu­lation air are measured, and the required air quantities are calcu­lated in advance. This achieves optimal combustion results and emissions values in all load stages, including with difficult fuels. The grate of the Pyroflex SRT is divided into up to four independent primary air zones. This allows the required air quantities to be adapted to the fuel.

Use of high-quality O2 probes

The secondary air flow rate is regulated based on the detected oxygen level. High-quality O2 probes make it possible to maintain a conti­nuously low residual oxygen level in the flue gas (approx. 4–5% O2 (damp) – depending on the fuel). This allows the highest levels of efficiency to be achieved even in modulating partial load operation.

Automatic ash removal

Several variants are available for removing ash from the combustion chamber as well as the cyclone and electro­static filter, depending on the fuel and ash content. The ashes can be discharged jointly or separ­ately. They are deposited into containers of up to 800 l or in settling pits of 5.5 to 12 m2. They can also be filled into big bags.

The following variants are available:

  • With trough chain conveyor
  • With screws
  • Laterally from the combustion chamber
  • Directly under the combustion chamber