JPS6235563B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an incinerator in which a hearth portion is formed by a plurality of stepped fire grates.

According to an incinerator in which a plurality of fire grates forming a hearth section have steps, the steps have the following advantages.

(1) The drying, combustion, and after-combustion zones are easy to define and operation monitoring is easy.

(2) Operation control can be performed mainly by controlling the operation of the grate stage, and it is easier to control disturbances in the fuel on the hearth than in the case of a single hearth.

(3) For water-containing fuel with a low calorific value, the ignition and combustibility is improved due to the reversal and crushing effect of the fuel due to the furnace firing step.

However, while it has these advantages, it also has the following disadvantages.

(1) In the case of high calorific value fuels, in order to improve the ignition and combustibility of the fuel, the temperature of the hearth and hearth walls where the fuel falls from the drying grate to the combustion grate allows rapid combustion. becomes very high or the fuel on the dry grate is exposed to flame radiation and starts to partially burn. Therefore, in addition to shortening the life of the front part of the combustion grate, when trying to maintain the fuel on the dry grate in a reducing atmosphere in order to reduce NO _x , the partial combustion of the fuel on the dry grate Since NO x cannot be suppressed, the cyclic atmosphere cannot be maintained and suppressed combustion of NO _x is difficult.

(2) Due to changes in fuel properties such as moisture content and lower calorific value, the combustion zone may shift backwards and straddle the combustion grate and post-combustion grate. Combustion on the post-combustion grate is difficult to connect because the flame radiation above the grate is blocked and the burning fuel is separated by the steps. For this reason, it is difficult to stably burn the fuel in the post-combustion grate, so the post-combustion grate may not be fully utilized for fuel combustion.

(3) Because the amount of fuel falling from one grate to the other is not constant, it is difficult to make the layer thickness of fuel on each grate uniform and to stably carry out reactions such as combustion in the hearth. .

The above-mentioned disadvantages are unique to incinerators that have steps in the multiple grate forming the hearth, and are a phenomenon that cannot be seen in incinerators with a single hearth without steps in the hearth. It is. In this way, depending on the properties of the fuel such as moisture content and lower heating value, it may be desirable to have a step in the hearth, or it may be desirable not to have it. In some cases, the presence or absence of a step in the hearth can be determined at the planning stage depending on its properties, but for fuels whose properties are not constant and vary widely, such as garbage, It is very difficult to decide whether there is a step or not, and even if one is decided upon after thorough consideration, it may be determined that the opposite choice should have been made depending on changes in the properties of the fuel. There are many cases.

The present invention aims to solve such problems, and provides an incinerator in which a hearth portion is formed by a plurality of grate, in which the grate is swingable via a horizontal axis at the end on the fuel discharge side. This object is achieved by providing an incinerator in which the hearth portion is configured to be switchable between a state having a step and a state having a single hearth without a step, This makes it possible to perform stable combustion operation even in the face of large changes in the properties of the fuel, and to perform combustion by effectively utilizing the hearth area, thereby increasing the lifespan of the incinerator. This makes it possible to reduce NO _x in exhaust gas.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be explained in detail below based on the drawings showing one embodiment thereof.

The drawing shows a waste incinerator. In the figure, 1 is a garbage supply hopper, and 2 is a hearth part for burning the garbage 3 supplied from the garbage supply hopper 1, which is formed by a plurality of stepped grates 4, 5, and 6. There is. Grate 4, 5, 6 in order from the top,
They are a drying grate 4, a combustion grate 5, and a post-combustion grate 6, of which the drying grate 4 is fixedly provided, and the combustion grate 5 and the post-combustion grate 6 are each located at the waste (fuel) discharge side end. It is provided so as to be swingable via the horizontal axis 7 of the section. 8 is a grate rotating device provided below the combustion grate 5 and the post-combustion grate 6; a drive motor 9 provided outside the furnace; a worm 10 interlocked therewith; and a worm wheel 11 meshed with the worm 10. a rotating shaft 12 attached to the end and provided along the furnace width direction; an arm 13 integrally provided with the rotating shaft 12 and an appropriate location in the furnace; and a combustion flame between the tip of the arm 13 and the combustion flame. It is composed of a rod 14 whose both ends are connected to the lower surface of the grate 5 or the lower surface of the after-combustion grate 6 via a pin joint, and which connects these, and serves to rotate the combustion grate 5 and the after-combustion grate 6. It is something. Reference numeral 15 denotes a guide member provided facing the waste supply side end surfaces of the combustion grate 5 and the post-combustion grate 6;
When the combustion grate 5 and the post-combustion grate 6 rotate, they serve to guide the end faces thereof well.

The operation of this configuration will be explained next. First, when normal garbage 3 is being supplied from the garbage supply hopper 1, conventional combustion operation is performed while maintaining the level difference between the respective fire grates 4, 5, and 6. When the high calorific value garbage 3 etc. is supplied, the grate rotation device 8 is operated to appropriately swing the combustion grate 5 or the post-combustion grate 6 upward, and each grate 4 ，
The steps 5 and 6 are narrowed or eliminated. In this case, when the drive motor 9 is rotated, the worm 10 is rotated, and as the worm 10 is rotated, the worm wheel 11 is also rotated. As the worm wheel 11 rotates, the rotating shaft 12 rotates, and the arm 13 rotates to push up the rod 14. Incidentally, the combustion grate 5 shown in the figure is shown in the lowest position, and the post-combustion grate 6 is shown in the highest position. Therefore, if both the combustion grate 5 and the post-combustion grate 6 are placed at the highest position, they will function as a single incinerator. This makes it possible to stably burn the supplied garbage 3 with a high calorific value. In other words, it is possible to prevent the high calorific value garbage 3 from falling at the stepped portion and being suddenly burned. As a means for fixing the positions of the combustion grate 5 and the post-combustion grate 6 after swinging, for example, the torsion angle of the worm wheel 11 is made small enough to allow self-locking, and the cantering motor 9 is connected to an electromagnetic device as a double locking mechanism. A brake may be provided. Further, the grate rotating device 8 is not limited to the one in this embodiment, and may be configured to directly push up the grate 5, 6 from below with a hydraulic cylinder. Furthermore, if both the combustion grate 5 and the post-combustion grate 6 are placed at a low position, the hearth portion 2 will have a step, so even water-containing fuel with a low calorific value may fall at the step. Can burn well.

As described above, according to the present invention, since the grate is provided so as to be swingable via the horizontal shaft at the end on the fuel discharge side, it is possible to swing the grate so that the hearth part has a step. This makes it possible to drop water-containing fuel with a low calorific value, such as ordinary garbage, at the step and burn it well, and also to swing the hearth into a single hearth with no steps. This allows the fuel to flow without falling, allowing fuel with a high calorific value to be burned without damaging the grate or producing large amounts of _NOx . Therefore, it is possible to perform stable combustion operation even in the face of large changes in the properties of the fuel, and it is also possible to perform combustion by effectively utilizing the hearth area, thereby increasing the life of the incinerator. , NO _x in exhaust gas can be reduced.

[Brief explanation of the drawing]

The drawing is a longitudinal sectional side view of a garbage incinerator showing one embodiment of the present invention. 2...Heart part, 4...Drying grate, 5...Combustion grate, 6...Post-combustion grate, 7...Horizontal axis.

Claims (1)

[Claims] 1. In an incinerator in which a hearth portion is formed by a plurality of fire grates, the fire grate is swingable through a horizontal axis at a fuel discharge side end, and the hearth portion has a step; An incinerator characterized by being configured to be switchable between a single hearth with no steps.