Grate firing system for difficult-to-ignite fuels with a fuel drying shaft upstream of the grate.
Patent Information
- Application Number
- DER0103391
- Authority / Receiving Office
- DE · DE
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 1938-09-24
- Publication Date
- 1940-12-04
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Existing grate furnaces struggle with incomplete combustion and excessive fly ash formation when firing fuels with high moisture content, such as raw lignite, due to inefficient ignition methods that lead to explosive ignition at the end of the grate.
An auxiliary grate is positioned at the upper end of the drying shaft outlet to provide top ignition, ensuring uniform combustion by connecting it to a layer controller for even fuel distribution and ignition across the grate surface.
This solution enables complete and uniform combustion of moist fuels, preventing explosive ignition and reducing fly ash formation, allowing for trouble-free furnace operation even with load fluctuations.
Description
[0001] Grate furnace for difficult-to-ignite fuels with a fuel drying chute upstream of the grate. In inclined grate furnaces. For moist fuels, it is known to be located in the lower part of the drying shaft in front of the grate, on the side facing the combustion chamber. To arrange roof-shaped grate bars on the side, through which the fuel flow is distributed to two upstream auxiliary grates. Furthermore, it is necessary to Traveling grate furnaces are known to have an auxiliary grate at the lower end of the fuel supply shaft, serving to form ignition nests. to arrange for the fuel falling onto the grate to be ignited from below. However, the resulting under-ignition has, in particular, With fine-grained fuels of high moisture content, such as raw lignite, the disadvantage is that the moist fuel is present on most of the The rust is only partially dried and only ignited at the end of the rust, with the ignition occurring explosively and resulting in heavy fly ash formation. This causes problems. Therefore, with under-ignition, proper operation of the combustion system cannot be achieved when using moist fuels.
[0002] The grate firing system forming the subject matter of the invention, with a fuel drying shaft upstream of the grate, is suitable especially for burning difficult-to-ignite fuels, primarily fuels with very high moisture content, such as raw lignite. To ensure a To achieve flawless ignition in this combustion system, the auxiliary grate at the outer end of the [unclear text] serves to form ignition nests. The auxiliary grate, used to create ignition nests, is located on the walls of the drying shaft facing the firebox. upper side the outlet opening of the drying shaft, so that the fuel coming from the drying shaft onto the grate receives a super-ignition, which This results in a uniform combustion process while avoiding significant fly ash formation, thus ensuring completely trouble-free operation of the combustion system. is made possible.
[0003] So that, at different heights of the fuel layer located on the grate, glowing fuel is drawn evenly from the auxiliary grate If the fuel layer reaches the surface, it is recommended to connect the auxiliary grate to the layer regulator so that the auxiliary grate... can immediately follow different positions of the shift controller.
[0004] As a result of the pre-ignition acting as top ignition, the further advantage is achieved that the combustion process is uniform extends over the entire grate surface, preventing uneven combustion processes, especially during load fluctuations.
[0005] An embodiment of the invention is shown in longitudinal section in the drawing.
[0006] The combustion system used to heat a steam generator consists of a grate i, which is operated in the usual manner by means of a rod. is driven. In front of the end wall 3 of the combustion chamber 2, a shaft 4 is arranged, into which the fuel supplied from a bunker, e.g. B. Raw lignite, is subjected to pre-drying by air, which is achieved through the louver-like openings attached to the front of the shaft. The first rows of plates io of the grate are completely closed, so that the downward wind only passes through the remaining air-permeable parts of the combustion chamber located below the actual firebox. a grate can pass through it. A trough grate 7 is arranged at the top of the exit opening 6 of the shaft 4, which is arranged around a horizontal Axis 8 is pivotable. The M-trough grate is expediently connected to the layer regulator so that it can move vertically with it. is moved. A portion of the fuel located in shaft 4 is dammed up by the grate. Since the lower part of the dammed-up fuel... As the fuel begins to glow, ignition pockets form on the grate. The glowing fuel passes from the grate 7 onto the grate from the Fuel entering the shaft and passing over the grate, consequently receiving a glowing surface layer, which causes rapid ignition of the fuel. Therefore, when the downward air supply enters the combustion chamber, complete combustion can occur quickly, even if the brine still has a relatively high moisture content.
[0007] The combustion system can be used in steam generators of various designs and also enables the use of fuels with high volatility. Moisture content allows for rapid and complete combustion.
Claims
[0008] PATENT CLAIMS: i. Grate firing for difficult-to-ignite fuels, in particular fine-grained fuels with high moisture content, characterized by a fuel drying shaft upstream of the grate, in the lower part of which an auxiliary grate is pivotably installed, that the auxiliary grate serving to form ignition nests is located at the lower end of the wall (3) of the drying shaft (4) facing the combustion chamber is arranged.
2. Grate firing according to claim i, characterized in that the auxiliary grate (7) is arranged with the component that is movable on the dry shaft wall. Layer controller (9) is connected.