The Wellons Canada reciprocating step grate is an air-cooled grate utilizing our proprietary designed grates offering high temperature performance and corrosion resistance. The Wellons Canada reciprocating step grate combustor burns a range of higher moisture content fuels.
Combustion Principles
Applications
Designed For Biomass Firing
Wellons provides single systems ranging in size from 20 MMBTU/hr to 200 MMBTU/hr gross output in multiple applications. Wellons custom designs reciprocating step grate combustors based on required energy requirements and fuel characteristics.
Maximum turndown ratio up to 3:1 can be achieved.
Combustion Principles
The reciprocating step grate offers a high level of operator control to ensure complete combustion.
Combustion is controlled in three zones on the grate – the drying zone, the combustion zone and the ash zone. The fuel residence time and travel speed can be individually controlled in each zone. In addition, the combustion air is controlled by individual under fire air zones and individual secondary and tertiary fans to provide an enhanced level of combustion management.
Primary Air, or underflow air, is forced into a plenum underneath the stepped grate in order to promote drying and gasification. The primary air is zoned on the length of the grate creating the ability to fine tune the quantity of air through the grate by adjusting dampers outside of the unit.
The Secondary Air nozzles are high velocity jets placed above the grates that cut across the combustion chamber in order to complete oxidation of the gases leaving the grate.
Fuel feed is precisely controlled by way of independent fuel rams which distribute a uniform thickness of fuel across the width of the grate.
Automatic Ash Removal off of the end of the step grate or under the step grate is achieved either by a wet ash conveyor or a dry ash conveyor depending on the size of the unit and the preference of the customer.
Combustor Applications
The reciprocating step grate can be used in Steam, Thermal Oil, Hot Water, or Direct-Fired (Hot Gas Generator) applications.
