JPH0238852B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an installation for burning solid fuels (hereinafter referred to as polluting fuels) that generate dirty combustion gases, preferably coal, in a fluidized bed combustion chamber.
A mixture of fuel and an absorbent that adsorbs impurities is
It is fed into the fluidized bed using a pneumatic feeding device. Absorbents made of dolomite or mica adsorb the sulfur present in the carbon during the combustion of the carbon, reducing the concentration of sulfur dioxide in the flue gas to an acceptable value.
The invention is particularly intended for installations with combustion chambers that are operated at high pressures, for example from 10 to 16 atmospheres (high-pressure fluidized bed combustion installations).

The aim of the invention is to provide an installation in which the absorbent is fully utilized. To achieve this objective, fuel and absorbent are mixed and supplied to a plurality of locations in the fluidized bed by means of pneumatic feeders. The amount of absorbent in the fuel and absorbent mixture is continuously adjusted in relation to the concentration of sulfur dioxide in the combustion gases leaving the fluidized bed.

This equipment has separate containers for fuel and absorbent. These vessels are connected via individual delivery circuits to a pneumatic supply device for supplying fuel and absorbent to the combustion chamber. There is a transducer within or after the combustion chamber that measures the concentration of sulfur dioxide in the combustion gases. This converter is connected to a signal processor in which a comparison is made between the measured value of the input signal and the set value. This signal processor is connected to a regulator. This regulator adjusts the difference between the actual measurement value and the set value.
For example, the rotational speed of the electric motor that drives the absorbent batcher is determined.

The fuel container and the absorbent container may also be connected to the pneumatic supply device in other ways. In one embodiment, these containers are connected to the supply device using separate conduits. In another embodiment, the feed device may also include two parallel conduits that merge into one common feed device immediately before the combustion chamber. In this case, the fuel container and the absorbent container are each connected by one conduit to one of the two parallel supply conduits.

By supplying fuel and absorbent together,
The absorbent has the advantage of coming into contact with the produced sulfur dioxide as soon as it enters the fluidized bed. The fine particles of the absorbent instantly absorb sulfur. If the absorbent were to be fed without this method, it would pass through the fluidized bed and some of the fines would be entrained in the flue gas unutilized. This feeding method, together with the continuous adjustment of the batch amount taking into account the concentration of sulfur disulfide in the flue gas, significantly reduces the consumption of absorbent. become.

The details of the present invention will be explained below with reference to the accompanying drawings.

FIG. 1 shows a fluidized bed combustion chamber, which is a pressure chamber for driving a gas turbine, for example. This diagram is
Furthermore, a fuel container 2 and an absorbent container 3 are also shown. At the outlets of these containers there are a batch machine 4 and a batch machine 5 that deliver the raw materials in the required amount. According to the invention, the output from the batchers is directed to a common conduit 6. This common conduit 6 communicates with a nozzle 7 or the like, which is provided in a feed conduit 8 extending to the bottom of the fluidized bed. Compressed air is supplied via an adjustable throttling device or valve 9 to convey the fuel and absorbent mixture to the fluidized bed.

This arrangement provides the advantage of intimate mixing of air, fuel and absorbent when they are fed into the fluidized bed through suitable combustion nozzles. In this way, while the fuel is being heated and burned, the impurities will be separated from the fuel and at the same time the absorbent will take effect. At this time, if the absorbent is supplied in powder form, the utilization of the absorbent will be high.

The fuel batcher 4 is constantly adjusted in a known manner as a function of the set load of the combustion chamber or of the turbine. The absorbent batcher 5 is appropriately adjusted mainly depending on the amount of fuel supplied. However, it cannot be expected that the fuel will always maintain a constant composition, and rather the amount of impurities will change, so it is not always sufficient to adjust the amount of absorbent in relation to the amount of fuel alone. . Therefore, the electric motor 10 that drives the batch machine 5 is appropriately controlled by the regulator 11 according to the amount of fuel and the impurity concentration in the fuel. This means that, as shown in the figure,
For example, this is carried out using a converter 13 which measures the concentration of sulfur dioxide in the exhaust gas from the fluidized bed. The measured value here is compared with the set value in the input circuit 12 to the regulator 11. In this way the required supply of absorbent is ensured. As a sulfur dioxide detector,
For example, thermoelectron (Thermo-
There is an optical analyzer called Electron (trademark).

FIG. 2 shows a modification of the embodiment of FIG. 1, in which batch dispenser 4 and batch dispenser 5 are connected to feed nozzles 14 and 15 in conduit 8, respectively.

In FIG. 3, nozzles 14 and 15 are connected to conduit 8.
Each is incorporated into two parallel conduits connected to the In this case, the amount of conveying air is
Two valves 9 provide individual regulation for fuel and air.

The amount of conveying air is primarily adapted to ensure the conveyance of the raw material to the combustion chamber. This air is also used as the actual combustion air at the same time. Secondary combustion air, additional air for temperature regulation and fluidized bed formation are supplied in a conventional manner (not shown).

FIG. 4 shows a batch machine 4 having a cylindrical chamber in which an impeller 20 is installed. The fuel arrives from the container 2 and slides into the chamber incorporating the wheel 20. By changing the rotational speed of the impeller 20, the amount of fuel supplied is adjusted. Conveying air nozzles 14 are placed in the conduit downstream of the batcher. This nozzle has a chamber around the conduit, and the conveying air is introduced through a conduit 23 on the side of this chamber. Air enters from this chamber through slots in the sides of the tubes extending downstream of the batcher, and the fuel flows down with the air into the conduit 8 leading to the combustion chamber 1. Similar equipment can be used for absorbents. According to the principle of FIG. 1, batch divider 4 and batch divider 5 are connected in parallel to one common air nozzle through conduit 6, whereas in FIG. Two devices are connected to conduit 8 in parallel. In the device shown in FIG. 2, nozzle 14 and nozzle 15 are integrated as a simple T-shaped component.

[Brief explanation of drawings]

FIG. 1 shows the equipment of one embodiment of the present invention. Second
3 and 3 each show a modification of the equipment shown in FIG. 1. FIG. 4 shows details of the batcher and nozzle for supplying conveying air to the conduit. In the figure, 1... fluidized bed combustion chamber, 2... fuel container, 3... absorbent container, 4... fuel batcher, 5... absorbent batcher, 6... common conduit,
7... Nozzle, 8... Pneumatic feeder, 11... Regulator, 12... Signal processor, 13... Converter, 1
4... Conveyance air nozzle.

Claims (1)

Claims: 1 Fluidized bed combustion chamber 1 to which a mixture of fuel and absorbent is supplied by a pneumatic supply device 8
In the equipment for burning polluting solid fuel, the system is connected to the pneumatic supply device 8 via a batch machine 4 that adjusts the amount of fuel supplied and a batch machine 5 that adjusts the amount of absorbent supplied. a first container 2 for fuel and a second container 3 for absorbent, a converter 13 for measuring the concentration of sulfur dioxide in the combustion gas in or after the combustion chamber; A signal processor 12 that compares the value with a set value, and a batch unit 5 for absorbent connected to this signal processor 12.
A combustion facility for polluting solid fuel, characterized in that it has a regulator 11 that adjusts the flow rate of the polluting solid fuel. 2. Combustion according to claim 1, characterized in that the fuel container 2 and the absorbent container 3 are connected to the pneumatic supply device 8 via respective conduits and nozzles 14, 15. Facility. 3 The fuel container 2 and the absorbent container 3 are
2. Combustion installation according to claim 1, characterized in that it is connected to a common conduit (6) which is connected to a pneumatic feed device (8). 4 The fuel container 2 and the absorbent container 3 are
Combustion according to claim 1, characterized in that each is connected to a pneumatic conveying conduit and these conduits are connected to a common feed device (8) in front of the combustion chamber (1). Facility.