BTG Model

It is a combustion unit with a conveyor grate mounted under the water pipe primary combustion chamber.

The rotary grate is made of heat-resistant special alloy casting material. When it comes to the chain links, they are designed to create thin air outlets between them in order to provide combustion on the entire surface. The combustion capacity can be kept at the desired level by supplying the required amount of combustion air to the grate from below through numerous air channels and adjustment valves.

The most suitable coal that the rotary grate should use is whose volatile matter should account for at least 35% and has the size of a grain of rice which is approximately between 3 to 10 mm.

From the moment the coal is poured into the grate from the loading bunker, it moves into the furnace with the rotation speed of the grate. The coal layer laid on the grate is adjusted by a manual mechanism depending on the quality of the coal, the burning speed, etc. When it first enters the furnace, the coal first begins to release its moisture under the influence of radiation heat and then gasify as the temperature increases. From that, volatile-flammable hydrocarbons are release, and the coal completes the combustion of fixed carbon in the further parts of the grate.

The coal must completely burn at the end of the grate. The ash of the coal that has completed its combustion is discharged from the end of the grate with an appropriate ash removal system. After discharging the coal, it returns under the combustion zone, and cools down since it is not exposed to combustion. As a result, the grate does not experience considerable thermal deformation as it is not exposed to elevated temperatures.

The burning speed will vary depending on the composition of the coal. The rotation speed of the grate is adjusted by the inverter and is selected to best suit the burning of the coal at hand. The speed of the grate also changes depending on the steam pressure.

Immediately after being laid on the rotary grate, the coal is spread evenly over the entire grate surface and in the desired thickness through the adjustable system located behind the bunker. The coal starts to burn homogeneously at the entrance of the furnace until the end of the grate.

There are primary air channels at the bottom of the grate, where the flow rate can be adjusted with separate valves. The ability to control the air channels separately allows zoning the combustion zones separately.Since the combustion is complete, the remaining amount of slag is quite small, and the latter is poured into the slag trough. The ash of the coal that has completed its combustion is poured into the wet ash removal system and from there it is discharged from the boiler via a pallet scraper.

The chamber at the front of the grate is specially designed to let unburned coal slipped under the grate accumulate and automatically removed from there.

The conveyor grate and the boiler are placed on a flat concrete floor, minimizing the customer’s construction cost, which is one of its most important advantages.

The coal to be burned must be of quality in accordance with the regulations defined by the Ministry of Environment and Forestry. Coal with low ash, moisture and sulfur content and high calories should be preferred.

Combustion air and secondary air are supplied in a controlled manner from both sides of the grate, ensuring that it is cooled and the combustion occurs on the its entire surface.