The grate has two very important tasks:
- Maintain the combustion process in the oven or fireplace chamber, ensuring the flow of air due to natural convention through the ash pan, from below;
- Ensure ash removal from the furnace after combustion. If the ash elements are not removed, the air passage into the furnace will be closed, this will negatively affect the efficiency of the furnace..
The grate is located between the ash pan and the combustion chamber, separating the two parts of the furnace, but without interfering with air circulation. In the fireplace, the grate is simply installed in the firebox, providing air supply to the fuel from below.
Grates are of the following main types:
- flat slabs. The most common option, simple and easy to install;
- girder. Composite grates, they are assembled from separate beams of the same size, independently adjusting the distance between them. A convenient option if the furnace is of a non-standard size and it is difficult to find a ready-made grate. In addition, if one beam burns out, it can be easily replaced;
- round grates, are used in furnaces with a corresponding firebox shape, for example, in stoves. Can be solid or in two halves, prefabricated;
- stand out separately grate for fireplaces, which are most often created in the form of a basket, providing a convenient arrangement of firewood for burning. Grids for fireplaces often become an element of decor, therefore they are made forged, graceful, delicate, but at the same time functional;
- movable gratesused in more complex devices, for example, in boilers and long-burning furnaces, in industry.
As a variant of tiled flat grates, there are parts with round holes, and not in the form of a lattice. Such, in particular, can be used in hearth furnaces where there is no ash pan at all.
As for the material of manufacture, most often the grates are made of cast iron. This metal serves for a long time, but it is quite fragile, so it is very important not to hit the cast iron grates, and clean the ash carefully. In addition, in order to extend the life of the cast iron grate, do not extinguish the fire in the stove with water! A sharp temperature drop has a very negative effect on the metal, it can simply crack. Steel, in comparison with cast iron, has the worst heat-resistant properties and can deform due to temperature changes, therefore it is used less often in the production of grates..
Important! For firing coal, you should choose grates with the following dimensions: 350x200x30, 300x200x30, 400x300x30 mm. Grids with dimensions of 300x200x15, 350x250x20, 250x252x20, 245x135x25 mm are suitable for wood burning. Coal grates are always heavier, more massive, as they have to withstand a more solid weight of fuel.
In the furnace, the grate is installed with the narrow side of the ribs down, which prolongs its service life. Ash slots should occupy at least 40% of the entire grate area in order to provide air flow and ash fallout, but to avoid large chips and coals falling into the ash pan.
Choosing a grate is better than factory production, from high-quality cast iron grade SCh15 (20). You should focus on the size of the furnace of your stove and the type of fuel used. Coal grates are also suitable for wood burning, this is a more versatile option.
As for the price, it will, of course, be different. For example, the cost of a cast-iron grate measuring 350×205 mm is about 800-900 rubles. You can find grates 300×200 mm and for 450-500 rubles. Forged grates for fireplaces will be the most expensive, their cost can reach 5-7 thousand rubles.