JPS6235564B2 - - 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 fuel with a high calorific value, the ignition and combustibility of the fuel improves, so the fuel combusts rapidly at the position where it falls from the drying grate to the combustion grate, so the degree of immersion in the hearth and furnace walls. becomes very high or the fuel on the dry grate is exposed to flame radiation and starts to partially burn. For this reason, 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 NOx, partial combustion of the fuel on the dry grate is suppressed. Therefore, it is difficult to maintain a reducing atmosphere and suppress NOx combustion.

(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. Since the flame radiation above the grate is blocked and the burning fuel is separated by the steps, combustion on the post-combustion grate is difficult to sustain. 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. As described above, depending on the properties of the fuel, such as its moisture content and lower calorific value, it may be desirable to have a step in the hearth, or it may be desirable not to have a step. If the properties of the fuel are constant, the presence or absence of a step in the hearth can be determined at the planning stage depending on the properties. It is very difficult to decide whether there is a step in the hearth or not, and even if one is decided after careful consideration, the opposite choice may need to be made depending on changes in the properties of the fuel. There are many cases where it is determined that the

The present invention aims to solve such problems, and provides an incinerator in which a hearth portion is formed by a plurality of stepped grates, in which the fuel discharge side end of the upper grate is located at the stepped portion. A movable wall is provided so as to be swingable via a horizontal axis provided in the hearth, and the hearth can be switched between a discontinuous state with steps and a continuous state by the upper surface of the movable wall. This purpose is achieved by providing an incinerator, which enables stable combustion and operation even when the properties of the fuel fluctuate significantly, and which makes use of the hearth area effectively. As a result, the life of the incinerator can be increased and NOx in the exhaust gas can be reduced.

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,
These are the drying grate 4, the combustion grate 5, and the post-combustion grate 6, and the portions corresponding to the vertical walls of the stepped portions are
A step adjustment flapper 8 is provided as a movable wall that is swingable via an upper horizontal shaft 7 attached to the waste discharge side ends of the drying grate 4 and the combustion grate 5. Reference numeral 9 denotes a flapper rotation device provided behind the step adjustment flapper 8, and a first flapper which is connected to a hydraulic cylinder 10 provided outside the furnace through a pin joint at the end thereof to the rod tip of the hydraulic cylinder 10. Lever 1
1 is installed, and the first
A second lever 1 extending substantially perpendicular to the lever 11
2 is attached to a rotating shaft 13 along the furnace width direction;
It is comprised of a second lever 12 of this rotating shaft 13 and a rod 14 which is connected at both ends to the back surface of the step adjustment flapper 8 via a pin joint and connects them, and serves to rotate the step adjustment flapper 8. It is something. Reference numeral 15 denotes a guide surface provided at the ends of the combustion grate 5 and the after-combustion grate 6 on the waste supply side, and serves to rotate the step adjustment flapper 8. Reference numeral 15 denotes a guide surface provided at the waste supply side ends of the combustion grate 5 and the post-combustion grate 6, which functions to guide the lower end surface of the step adjustment flapper 8 well when it swings. be.

The operation of this configuration will be explained next. First, when normal garbage 3 is being supplied from the garbage supply hopper 1, as shown in the lower step adjustment flapper 8 in the figure, the flapper rotation device 9 is used to rotate the step adjustment flapper 8 upward, Carry out combustion operation as usual while maintaining the level difference. Then, when the high calorific value waste 3 etc. is supplied, the flapper rotation device 9 is operated so that the fuel incineration surface of the hearth part 2 is continuous, as shown by the level difference adjusting flapper 8 in the upper part of the figure. The step adjustment flapper 8 is appropriately rotated downward to make the inclination angle at the step portion gentle. As a result, the incinerator functions close to a single incinerator, and it becomes possible to stably burn the supplied waste 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. Further, by performing the combustion operation while maintaining the level difference as described above, even water-containing fuel with a low calorific value can be burnt satisfactorily by dropping it at the level difference part.

As described above, according to the present invention, since the movable wall is provided in the step part, the movable wall can be swung and used so that the hearth part is in a discontinuous state with the step, and normal garbage can be removed. It is possible to drop water-containing fuel with a low calorific value on a step and combust it well.
In addition, by swinging the movable wall so that the hearth is continuous with the upper surface of the movable wall, the fuel flows without falling, preventing high calorific value fuel from damaging the grate. It can be burned without producing large amounts of NOx or 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. , NOx in exhaust gas can be reduced.

[Brief explanation of the drawing]

The drawing is a vertical sectional side view of a garbage incinerator showing an embodiment of the present invention. 2...Heart part, 4...Drying grate, 5...Combustion grate, 6...After-combustion grate, 7...Top horizontal shaft, 8...Level adjustment flapper.

Claims (1)

[Claims] 1. In an incinerator in which a hearth portion is formed by a plurality of stepped grates, the stepped portion is swingable via a horizontal shaft provided at the fuel discharge side end of the upper grate. An incinerator characterized in that a movable wall is provided in the incinerator, and the hearth portion is configured to be switchable between a discontinuous state having steps and a continuous state by an upper surface of the movable wall.