RU2326288C1 - Furnace - Google Patents

Abstract

FIELD: mechanic engineering.

SUBSTANCE: invention relates to furnace mechanics and can be used for incineration of solid lump fuel in steam boiler furnace and hot-water furnace including mobile furnace of module design. Furnace includes grate consisting of a number of prismatic shape bars of different height, combustion chamber, charging hopper for fuel supply into combustion chamber and ash hopper to remove ash from combustion chamber. Grate bars are fixed to horizontal movable frame resting upon roller supports and being actuated with reciprocal oscillations by means of hydraulic cylinder. Grate bars are in the shape of trihedral prism with their height reducing from charging hopper to ash hopper. Grate bar prism edges directed to ash hopper are provided with channels to supply blown air under fuel layer. These channels form corners in combination with horizontal prism edges. The corners exceed those formed with latter prism edges directed to charging hopper.

EFFECT: improvement of fuel combustion, reliability of grate operation and decrease of furnace dimensions.

2 cl, 1 dwg

Description

The invention relates to a furnace technology and can be used for burning solid lump fuel in the furnaces of steam and hot water boilers, including mobile in a modular design.

A well-known firebox containing a mechanical oblique-repelling grate of the CCTI system (see V.I. Panin. Boilers of low and medium power. M: Stroyizdat, 1964, p. 117), which is inclined at an angle of 15 ... 20 ° to the horizon a lattice consisting of alternating moving and motionless grid-irons. The movable grates on one end lie on the fixed grates, and the other rest on the movable trolley, which receives a reciprocating motion through the traction system. At the end of the grate there are fixed horizontal slag grates. The work of the lattice is as follows. Fuel from the feed hopper enters the moving grates of the front of the grate, with which it is pushed successively into the furnace as it burns. In this case, agitating the fuel occurs, which prevents its sintering in the layer, at the same time, the resulting ash shell around the pieces of fuel is destroyed, which contributes to better coke burning. The heated air necessary for combustion is supplied under the grill.

The disadvantage of such a furnace is the complexity of the kinematic scheme of its grate, due to the need to ensure the mobility of each of the moving grates, as well as low reliability, due to the fact that the movable trolley and traction system are in the process of working in the high-temperature range. In addition, intense abrasion occurs when the moving grate is relatively motionless. To create the required inclination of the grate, a certain margin in the height of the furnace is required, which makes it difficult to use this type of grate in the furnaces of mobile boiler units of a modular type.

A firebox with a screwing bar of the VTI system is known (see R.G. Zakh. Boiler installations. M: Energy, 1968, p. 69), consisting of a fixed horizontal grate, assembled from cordless grate. Across the lattice in full width there is a movable shuruyuyu plank, which is a trihedral prism. The angle of inclination to the horizon of the front (towards the furnace) face of the prism is greater than the angle of inclination of the rear face, so that when moving forward, the bar grabs fuel from under the loading hopper, mixes and distributes it along the length of the grate, and also periodically dumps slag onto an additional grate. With the backward movement of the bar (due to the small angle of inclination to the horizon of its rear face), the fuel hardly moves backward, but only rises. Thus, the lacing operation is performed. When the bar moves forward, all the fuel lying on the grate moves in a wave-like manner, which contributes to its mixing, and during the reverse stroke, part of the hot fuel moves from the middle of the furnace to the front, which improves the ignition conditions of the fresh fuel entering the grate. Having made several partial moves, the bar carries out a full stroke to the end of the grate and dumps the slag into the slag hopper. As a result of multiple strokes of the bar, a rhythmic movement of fuel along the canvas of the grate from the loading to the slag hopper is organized. The bar is driven by swivel chains-rods, which, when the bar is reversed towards the loading hopper, are retracted into a special pipe. The articulated chains of the rod are driven by an electric motor through a gearbox. The air required for combustion is supplied under the grate in zones. In a fire chamber with a screwing bar, all three operations are mechanized: supplying fuel to the fire chamber, lining and slag removal.

The disadvantages of a furnace with a screwing bar are:

- increased overall dimensions, due to the large length of the drive rods, due to the need to ensure the movement of the screwing strap along the entire length of the grate;

- thermal cycling, the result of which is a significant incompleteness of fuel combustion, caused by the fact that the screwing plate enters the layer and replenishes it with fresh fuel relatively rarely, and the shurring operation during the reverse movement of the strip at any time is carried out only in any one zone of the grate ;

- rapid wear of the screwing strap due to abrasion as a result of friction on the surface of the grate during the movement.

Also known is a furnace containing a grate, made in the form of a number of differently high prismatic grate, driven by a shaft with cams, rotated by an electric motor, a combustion chamber, a feed hopper for supplying fuel to the combustion chamber and a slag hopper for removing ash from the combustion chamber by means of a screw conveyor (see USSR patent No. 506328, IPC F23B 1/22, publ. 1976).

The disadvantages of the known firebox with reciprocating moving grates are: a complex mechanism for supplying hot air to the combustion chamber, in this regard, incomplete combustion of fuel, a complex mechanism for moving the grate and, therefore, the large dimensions of the furnace.

The objective of the present invention is to increase the completeness of fuel combustion and the reliability of the grate, as well as reducing the dimensions of the furnace.

The problem is solved due to the fact that in the furnace containing a grate made in the form of a number of uneven grates of a prismatic shape, a combustion chamber, a loading hopper for supplying fuel to the combustion chamber and a slag hopper for removing ash from the combustion chamber, according to the invention, the grate is fixed to horizontal movable frame mounted on roller bearings and driven into a reciprocating oscillating movement with a certain frequency using a hydraulic cylinder, and made in the form of trihedral prisms with a decrease in their heights in the direction from the loading hopper to the slag one, and the faces of the grate prisms facing the slag hopper are provided with channels for supplying blast air under the fuel layer and form angles with horizontal faces of the prisms that exceed the angles formed with the last faces of the prisms facing to the loading bunker.

The problem is also solved due to the fact that the slag hopper can be equipped with a screw conveyor.

The drawing shows a diagram of the proposed furnace.

The furnace contains a grate, made in the form of a number of uneven grates 1 of a prismatic shape, mounted on a horizontal movable frame 2 mounted on roller bearings 3 and driven in a reciprocating oscillatory motion using a hydraulic cylinder 4, a combustion chamber 5, a loading hopper 6 for supplying fuel into the combustion chamber 5 and the slag hopper 7 for collecting ash from the combustion chamber 5 by means of a screw conveyor 8. Grids 1 are made in the form of trihedral prisms with a decrease in their heights in the direction from behind the load hopper 6 to the slag 7. The faces 9 of the grate prisms 1 facing the slag hopper 7 are provided with channels 10 for supplying blast air under the fuel layer and form angles with horizontal faces 11 of the prisms that exceed the angles formed with the last faces of 12 prisms facing loading hopper 6.

The proposed furnace works as follows.

When the horizontal movable frame 2 reaches its leftmost position, the leftmost grate 1 is loaded with a fresh portion of fuel from the loading hopper 6. In this case, the leftmost grate 1 cuts its flat face 12 into the fuel layer and comes under loading already filled. Due to the weight of the fuel in the loading hopper 6 and the force resulting from the interaction of the fuel on the grate 1 with the fuel in the loading shaft (not shown), part of the fuel is pushed to the next grate 1 towards the interior of the combustion chamber 5. This process moves the fuel along the grate the grate will be maintained while the oscillating reciprocating motion of the movable frame 2 relative to the combustion chamber 5 is maintained. Due to the fact that the amount of fuel on the grate its burnout decreases, the dimensions of the prismatic grates 1 should be proportionally reduced towards the slag hopper 7. The ash resulting from the combustion of fuel collides into the slag hopper 7 and is removed by the screw conveyor 8. When the grate moves back to the feed hopper 6 due to the small angle of inclination to the horizon of the verge 12 of the grid-irons 1 the fuel almost does not move backward, but only rises. Thereby, the lapping operation is performed, which occurs simultaneously at several points of the fuel layer corresponding to the positions of the grates 1, which contributes to the intensification of the fuel combustion process. To maintain the combustion process under the grates 1, blast air is supplied through channels 10. The possibility of reducing the dimensions of the furnace is achieved due to the fact that the grate is located horizontally, which reduces the height of the furnace. On the other hand, in the presented furnace, the stroke length of the hydraulic cylinder 4 rod is significantly reduced due to the fact that the movement of the grate on the stroke length of the hydraulic cylinder 4 is designed to provide only oscillatory movement of the grill, and the movement of the fuel layer along it is already its result. This allows you to reduce the length of the furnace, which is especially important for the creation of furnace devices of mobile boiler units in a modular design.

Claims (2)

1. A furnace containing a grate, made in the form of a number of differently high grate-bars of a prismatic shape, a combustion chamber, a loading hopper for supplying fuel to the combustion chamber and a slag hopper for removing ash from the combustion chamber, characterized in that the grate is fixed on a horizontal movable frame mounted on roller bearings and driven in a reciprocating oscillatory motion using a hydraulic cylinder, and are made in the form of trihedral prisms with a decrease in their heights in the direction from the loading hopper to w What are the, and faces of prisms grate facing the slag hopper, provided with channels for supplying combustion air below the fuel layer and form with the horizontal faces of the prism angles greater than the angles formed with the latter faces the prisms facing the feed tube. 2. The furnace according to claim 1, characterized in that the slag hopper is equipped with a screw conveyor.