JPH0348405B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coal-fired hot air stove that uses coal as fuel.

Figure 1 shows a coal-fired hot-air stove consisting of a typical stoker-type coal-fired furnace. It's getting old. In Figure 1, 1 is a coal feeder, 2 is a spreader, and 3 is a coal feeder.
is a movable grade that rotates counterclockwise in the figure, 4 is a coal ash removal feeder, 5 is a combustion air intake that takes in primary air, 6 is a combustion air inlet that takes in secondary air, 7 is a hot air extraction duct, and the inside of the furnace is lined with firebrick 8.

This stoker-type coal combustion furnace burns coal of various particle sizes. Therefore, the coal supplied by the coal feeder 1 is thrown into the furnace by the spreader 2. The larger the particle size of coal, the longer the combustion time, and the smaller the particle size, the faster it burns, so large diameter coal is scattered far away, small diameter coal is scattered towards you, and grade 3 is scattered in the opposite direction to the coal throwing direction. Move to. Therefore, coal of any particle size is completely combusted in the furnace.

A part of the combustion air is supplied as primary air from the combustion air intake port 5, and after cooling grade 3, it is ventilated to the coal seam above the grade. The remaining combustion air is supplied as secondary air through a number of combustion air blowing holes formed in the inner wall of the furnace, and is blown onto the upper surface of the coal seam.

Furnace combustion control and hot air temperature adjustment are
Mainly, the amount of combustion air for these two types, the moving speed of the grate, the amount of coal fed by the coal feeder, and
Adjusted by controlling the rotation speed of the spreader.

Although such a coal combustion furnace can generate high temperature gas with high combustion efficiency, it has drawbacks such as fluctuations in combustion gas temperature and clinker trouble due to melting of coal ash. The main cause is
One problem is that it is difficult to adjust the changes in combustion gas due to changes in the properties of fuel coal in the coal combustion furnace itself. Therefore, it has been difficult to use a stoker-type coal-fired hot air stove for applications where temperature fluctuations are not allowed or where higher temperature conditions are required.

That is, its drawbacks are as follows.

(1) Difficult to adjust for fluctuations in combustion gas temperature due to changes in coal properties.

(2) It is impossible to generate gas at a temperature higher than the melting point of coal ash.

(3) Clinker trouble occurs due to melting of coal ash.

The present invention solves the above-mentioned drawbacks and expands the scope of application of the stoker-type coal-fired hot air stove, and details thereof will be explained below with reference to embodiments shown in the drawings.

FIG. 2 is a longitudinal cross-sectional view showing one embodiment of the present invention. In the figure, the same parts as those in FIG.

In Fig. 2, the reference numeral 9 is an auxiliary burner installed in the hot air extraction direction in the hot gas duct 13, which is the hot air extraction part provided at the top of the stoker-type coal combustion furnace. It can be installed in an appropriate position to raise the temperature of hot air evenly. This auxiliary burner 9 uses fluid fuel whose fuel amount can be finely adjusted, that is, liquid and gas fuel. Fluid fuel is sent to the auxiliary burner 9 via a pipe 10 from an auxiliary fuel source 12 . An automatic valve 11 for flow rate adjustment is provided in the middle of the pipe 10. Further, in order to measure the temperature of the hot air heated by the auxiliary burner 9, a thermometer 14 is installed at an appropriate position in the hot gas duct 13. Further, a temperature setting device 15 is installed to control the automatic valve 11 for adjusting the flow rate, and the temperature inside the hot gas duct 13 is fed back from the thermometer 14, and the automatic valve for adjusting the flow rate is set to a preset temperature. 11 is controlled. The thermometer 14, temperature setting device 15, automatic flow rate adjustment valve 11, etc. form a hot air temperature control device that controls the combustion state of the auxiliary burner 9 and generates hot air at a constant temperature according to the temperature of the hot air outlet. are doing.

If such a structure is adopted, the generated hot air can always be maintained at a constant temperature even if there are fluctuations in combustion gas due to changes in coal properties or changes in conditions within the stoker type coal combustion furnace. Furthermore, the temperature of the hot air, which is limited due to the melting of coal ash, can be increased to a higher temperature by the action of this auxiliary burner. Furthermore, since the hot air temperature of the stoker-type coal combustion furnace can be lowered arbitrarily, clinker troubles are eliminated, and coal combustion furnaces do not have to shut down to remove clinker that has adhered to the inside of the furnace, unlike conventional methods. This enabled efficient continuous operation.
Furthermore, by branching the hot air extraction duct 7 into the required number and employing this device for each of them, several types of hot air can be extracted from one coal combustion furnace depending on the required temperature.

As is clear from the above description, according to the present invention, an auxiliary burner is installed in the hot air extraction duct of a stoker-type coal combustion furnace, and an auxiliary burner is installed to assist the temperature inside the hot air extraction duct to a desired value. Since the combustion state of the burner can be controlled, a constant high-temperature hot air can be supplied regardless of changes in coal properties or conditions inside the coal combustion furnace. Since there is no need to stop the operation, an excellent effect can be obtained in that efficient operation can be performed.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view illustrating a conventional structure, and FIG. 2 is a vertical cross-sectional view showing an embodiment of the present invention. 1... Coal feeder, 2... Spreader, 3... Mobile grate, 4... Coal ash removal feeder, 5, 6
...Combustion air intake, 7...Hot air extraction duct,
9... Auxiliary burner, 11... Automatic valve for flow rate adjustment, 12... Auxiliary fuel source, 13... Hot gas duct, 14... Thermometer, 15... Temperature setting device.

Claims (1)

[Claims] 1. A coal-fired coal-fired furnace equipped with a hot-air temperature control device that installs an auxiliary burner in the hot-air outlet of a stoker-type coal combustion furnace and controls the combustion state of the auxiliary burner according to the temperature of the hot-air outlet to generate hot air at a constant temperature. Hot stove.