Stokers, Distributors & Feeders
Stokers, Distributors & Feeders for Solid Fuel Applications
Riley Power Inc. maintains a complete product line of grates, distributors and feeders for solid fuel applications for new or retrofit applications for the power generation and industrial markets. Whether for firing biomass, refuse derived fuel, coal or similar types of fuels; Riley Power has the firing system that can meet your specification requirements utilizing modern designs and materials.
Traveling Grate Spreader Stoker
Riley Power’s Traveling Grate Spreader Stoker is designed to efficiently burn a variety of coals that have a wide range of coking, caking and ash fusion characteristics. In addition to coal, this stoker has proven effective in burning RDF, waste wood fuels, bagasse and other types of waste fuels.
The grate surface consists of small-sized clips of heat resisting alloy material mounted on lateral rack bars. The rack bars are attached to rugged conveyor chain assemblies that are supported on sturdy skid rails by heavy duty type skid shoes. All moving parts are protected from the high furnace heat. No mechanical stress is imposed on the grate surface. Only the weight of the fuel is carried.Riley Power’s Traveling Grate units combine the simplicity of design and robust construction which are characteristic of all RPI fuel burning components. A modular concept is available which permits the entire grate to be shipped in shop-assembled units, where transportation clearances are available. The savings in erection labor which result, and the advantages of shop assembly assure superior performance at a lower overall installed cost.The Riley Power Hydraulic Drive Unit incorporates separate power and mechanical drive units. Separate units permit flexibility in positioning for ease of installation and maintenance. The mechanical drive unit is directly connected to the grate drive, eliminating the need for variable speed drives with gears and sprockets. The drive is a heavy-duty design, capable of running in reverse to facilitate maintenance or relieve a grate jam.
Water Cooled Oscillating Grate
Riley Power’s Water Cooled Oscillating Grate(WCOG) is a relatively new and innovative firing system suitable for all stoker-grade fuels, including less expensive run-of-the-mine coal, requiring less power and providing higher unit availability and lower maintenance costs, The WCOG design is relatively simple and is suitable for not only new steam generator designs, but also for retrofitting to existing units.
Stationary Water Cooled Grate
RPI also offer a Stationary Water Cooled Grate that is suitable for burning cellulose fuels including wood. Stationary grate segments are fabricated from heat resistant castings supported by floor tubes in the furnace. Intimate contact with the floor tubes provides sufficient cooling to prevent overheating. Maintenance is low since there are no moving parts.
During operation, steam jets from nozzles located within the grate segments remove accumulated ash periodically. The motive energy provided by these jets propels the ash down the sloping grate surface and into the ash pit. Control of steam flow to the jets is accomplished by a piping network equipped with remotely actuated valves which can be programmed to clean the grate surface at predetermined intervals in a predetermined sequence.
Feeders and Distributors
Refuse Feeder – for bagasse, hogged fuel, and stringy waste fuels
The Riley Power Refuse Feeder is designed to feed bagasse, hogged fuel and similar stringy waste fuels to the RPI Pneumatic Distributor. A chain carrier carries fuel forward from the storage hopper to a conditioner roll that separates and shreds the fuel, feeding it at a regulated rate into the distributor chute. Further conditioning of the fuel occurs by aeration while it is falling in the chute and while it is in the air jet from the distributor. Feed rate is regulated by a rugged, variable speed drive, featuring a solid-state motor speed control for rapid, accurate response to fuel demand.
Vari-Flex Feeder – for coals
Pneumatic Refuse Fuel Distributors – for fibrous, spongy and high moisture content refuse fuels
The Riley Power Pneumatic Refuse Fuel Distributor spreads fuels uniformly over the entire grate surface to insure uniform depth of the fuel bed, rapid combustion, and smooth response to load changes. Fibrous, spongy and high moisture content refuse fuels, such as bark, bagasse, and other cellulose fuels can clog the moving parts of a mechanical distributor causing annoying and costly shutdowns. The Riley Power Pneumatic Refuse Fuel Distributor has no moving parts in the fuel stream. Fuel is fed to the distributor where it is propelled into the furnace and spread uniformly over the grate by a high velocity air jet. Pneumatic action breaks up chunks of fuel and wet masses to facilitate ignition. The smaller fuel particles are consumed while in suspension in the furnace, with larger particles burning on the grate.
The Pneumatic Distributors can be equipped with modulating dampers tied together on a line shaft with a variable speed drive. The dampers are sequenced to create a staggered, pulsating blast of air to each distributor, insuring even distribution of fuel over large grate surfaces.
Flyash Reinjection System – improved efficiency in refuse fired steam generators
Reinjection of the flyash collected in the boiler and dust collection hoppers improves the efficiency of combustion by recovery of unburned carbon and reduces the volume of ash/unburned carbon discharged from the unit. Riley Power has developed specialized equipment for ash reinjection in refuse fired units. The sand separator, a component designed for refuse applications, is used when firing fuels such as bark that are likely to carry non-combustible materials into the furnace. An inclined double-deck screen with an oscillating mechanism separates the larger high carbon flyash particles for reinjection into the furnace, while the smaller low carbon particles are discarded. Riley Power rotary valves are installed to assure free downward flow of the fly ash within the reinjection piping and to prevent an upward flow of gas from the furnace.