DZL Series Biomass Fired Hot Water/Steam Boiler

DZL Series Biomass Fired Hot Water Boilers are Water tube boilers with a single Drum designed to use a Chain Grate Stoker as a means of controlling the firing of a Biomass pellet, wood, or other biomass feed stocks. The DZL Boiler incorporates both Radiation and Convection heating surfaces, Water Walls (constructed on both sides of the furnace), and an Economizer and Dust Collector that improve combined Heat Transfer and reduce Emissions. DZL Biomass Boilers are commonly used in industrial boiler and heating applications and can be configured as either a Biomass Fired Hot Water Boiler or a Biomass Steam Boiler.

The DZL Chain Grate Boiler is a Grate Biomass Boiler that can accept a variety of Biomass Fuels, including Biomass Pellets, Wood Chips, Agricultural Residues, and Biomass Particles. The DZL Chain Grate Boiler can also be configured to Burn Coal or mixed fuels. The continuous operation of the DZL Chain Grate Stoker provides stable heating conditions and efficient Heat Transfer through effective Grate Combustion and stable Furnace Temperature, resulting in minimal unburned Carbon emissions.

A biomass-fired hot water boiler operates by using an enclosed furnace in which the Biomass (or fuel) is burned on a Chain Grate system, producing hot flue gases that are routed through a horizontal 3-pass water-tube or 3-pass fire-tube heat exchanger arrangement. Heat is transferred from the hot flue gases to water via the Radiation heating surfaces (walls) of the enclosure and the Convection heating surfaces (water tubes and the Economizer). Water is pumped through the boiler’s water wall and drum sections to remove heat from the boiler system and provide Hot Water for heating or process applications. The Design of the radiator and convection elements influences the boiler’s thermal efficiency.

The main parts that make up a DZL series steam-fired boiler include the boiler body (drum and water wall), the chain grate stoker, the furnace, combustion equipment (furnace), heat exchange tubes and tube plates, economizer, dust collectors, and control systems. The single-drum and water-tube layout provides excellent heat exchange capacity and durability of steam production. In addition, steam generators, feedwater pumps, and safety valves are essential components of a complete package.

Regular maintenance activities for a biomass boiler include: inspecting the fire and water tube areas; cleaning the chain grate and combustion chamber; scaling the water wall and drum; servicing the economizer and dust collector; verifying the control panel and safety devices. In addition to these routine maintenance activities, biomass boilers also require fuel preparation (pelleting or sizing), ash management, periodic interior tube cleanouts, and ensuring consistent, continuous, and safe combustion. All of these activities help reduce CO emissions and maximize the operational life of the boiler by providing continual heat transfer and safe combustion.

Controlled dust and flue gas treatments, better combustion methods (chain-grate), and efficient use of the biomass (high-quality biomass) help to minimize the components of particulate and gaseous emissions. Chain-grate combustion on a DZL boiler does not allow unburned biomass or CO emissions to be produced or to enter the combustion zone, with optimized air staging at appropriate times and optimized air quality. Using economizers and heat recovery can improve the overall environmental performance of older coal-fired boilers compared to DZL boilers.

A Biomass Boiler (DZL) has the ability to operate as either a Hot Water Boiler (DZL Series) or a Steam Boiler (DZL Series) depending upon its specified operating temperature and conditions. The Hot Water Boiler is utilized for circuit heating, while the Steam Boiler is designed to supply steam to various industrial applications (ex. food processing). Both types of Boilers feature an internal design consisting of tubes or drums, with varying designs for their tubes and drums, to deliver the desired outputs of Hot or Steam Water as required.

Grate design, fuel feeding, and proper distribution of combustion air greatly influence the efficiency of Chain Grate Biomass Boilers. Chain Grate Stokers and Tube Chain Grate Boiler designs allow for continuous movement of the fuel and a uniform distribution of heat between the grate surface, air, and the fuel. The optimized design of all combustion or furnace equipment (e.g., an economizer for heat recovery from flue gas) increases thermal efficiency and reduces fuel consumption.