JPS5880411A - Combustion apparatus - Google Patents

Abstract

PURPOSE:To prevent foreign matters from adhering to the inner wall of the combustion chamber to prevent combustion troubles from occurring by providing a preheating device on the upstream side of a cylindrical combustion chamber, in the titled combustion apparatus for a heat source in the hot water supply, room heating and the like using a powdery solid fuel. CONSTITUTION:When a granular fuel is ejected within a cylindrical body 61 of the preheating device 60 together with a heating flame, the fuel assumes a heated state and tarry parts contained in the fuel are gasified and the granular fuel which has been of caking property is converted to one having non-caking property. The coal system granular fuel whose property has been converted to non- caking property is blown off into the combustion chamber 1 through a fuel injection port 64 and comes into collision with the blow-through preventive cap 13, and mixed with a turbulance flow due to air from the primary air feed pipe 13 and burnt in a fluidized state. By these operations, adherence of foreign matters to the inner wall of the combustion chamber is prevented or the speed of adherence and accumulation of forein matters can be retarded, and hence occurrence of combustion trouble can be prevented and the number of times of cleaning within the combustion chamber can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides heat sources for hot water supply, space heating, greenhouses, dryers, etc.
The present invention relates to a combustion device using granular solid fuel, and particularly to a combustion device suitable for burning caking coal-based fuel.

Due to concerns about oil supply, there are calls for a review of coal and other solid fuels, but these solid fuels must be completely combusted;
Or it is difficult to obtain high firepower with a simple device.

Among these, so-called fluidized bed combustion, in which solid fuel is granulated (pulverized) and then combusted while being agitated and floated, is attracting attention as a combustion method that solves the above problems. It was difficult to completely carry out the combustion described above using a small combustion device.

In view of this background, the present applicant has already proposed a combustion device which is a small device and is capable of burning granular fuel in an agitated floating state.

Basically, this combustion device burns granular fuel by creating a vortex in multiple horizontal cylindrical combustion chambers, and guides the combustion gas to a combustion gas extraction chamber from a combustion gas extraction pipe facing into the extraction chamber. -3- It is designed so that it can be taken out to the outside, so that good combustion can be achieved.

However, with this combustion device, when burning non-caking coal-based fuel such as oil coke or coal coke cape, there is less chance of foreign matter, that is, combustion products, adhering to the combustion chamber wall, but it contains a large amount of tar. When caking coal-based fuel is burned, foreign matter may adhere to and accumulate on the inside of the combustion chamber, causing combustion problems such as incomplete combustion.
Otherwise, it may be necessary to carry out troublesome disassembly and cleaning.

The present invention has been made in order to solve these problems.The present invention has been made to preheat the coal-based granular fuel to be blown into the cylindrical combustion chamber, so that the tar content contained in the fuel is removed on the upstream side of the cylindrical combustion chamber. The fuel is characterized by being equipped with a preheating device (carbonization device) that gasifies the fuel and turns it into a non-caking substance.

The invention will now be described with reference to illustrated embodiments.

This combustion device consists of a combustion zone B and a preheating zone (carbonization zone) P, and the combustion zone B-see-JP-A-58-80411 (2) consists of a first and a second cylindrical combustion chamber l, - It has a combustion gas extraction house with a dust collection chamber J installed below.

Each of the chambers 1, 2, and 3 of the combustion zone B has a horizontal cylindrical shape with a horizontal axis, and includes a refractory material J on the outer periphery, a cylindrical body 4 provided inside the refractory material, and Bulkhead 7
v I 117jh et al. Bulkhead? , j are respectively provided with shaft communication ports 9 and 10 in their central portions, and the above-mentioned chambers communicate with each other through the communication ports.

Further, a plurality of communication holes are bored in the same region of the partition wall 74Cq% and are inclined in the direction of the vortex flow in the first cylindrical combustion chamber l. 1 is a cooling water or cooling air circulation pipe embedded inside the refractory material S, 1 is its inlet, /
is the exit.

Therefore, the preheating device for the preheating zone P (
Carbonization apparatus) In the SO, a cylindrical body 1 is positioned coaxially with each of the cylindrical chambers I, C, and *, and the end wall of this cylindrical body 4≦
The cylindrical body 6/ is made up of a constant diameter part 6/- on the fuel introduction pipe 63 side and a narrow part 6/on the cylindrical combustion chamber I side. The tip of the constricted portion &14 communicates with the fuel jet nozzle on one wall of the cylindrical combustion chamber l.

The above fuel introduction pipe No. 3 includes a fuel supply pipe Seri and a heating flame introduction pipe/
4 are inserted and connected together, and the fuel supply pipe slag is sequentially connected to the fuel mixing pipe j of the fuel storage hopper J and the flow valve I. A conveying screw core is inserted into the fuel mixing pipe j and is rotated by a drive device (Fig. 6).
Fuel is led into the fuel supply pipe/4L. The amount of fuel supplied can be adjusted by changing the rotational speed of the conveying screw 27, and the amount of air can be adjusted by changing the opening of the flow rate regulating valve U. On the other hand, the heating flame introduction pipe 14 is connected at its most upstream end to the above-mentioned flow valve via an on-off valve 19, and a gas cylinder J is connected in the middle thereof via an ejector/l and an on-off valve 19. . The heated gas mixed with air by the ejector/I is ignited by the ignition plug IK, and the heated flame, together with granular fuel from the fuel supply pipe 744,
The fuel is blown out from the fuel introduction pipe 63 into the cylindrical body 6/ of the preheating device 1o.

A blow-out prevention cap/J is attached to the shaft communication port 9 of the partition wall of the first cylindrical combustion chamber l. This cap/3 prevents the granular fuel ejected from the fuel injection port 6 from blowing into the second cylindrical combustion chamber before being burned, and a plurality of communication ports/3el are perforated on the same surface. It is set up. As shown in Figures 2 to 5, the first and second cylindrical combustion chambers and the combustion gas extraction section are as follows:
The primary, secondary, and
Tertiary air supply pipe/j, ko9. x.

31 are open, and these supply pipes 15. 9. x.

31 are on-off valves n1.3, 3J, 311 respectively
- is connected to the processor via. Two secondary air supply pipes A9, , :IO are opened in the second cylindrical combustion chamber, but it is also possible to have only one.

The dust collection chamber J connected below the combustion gas extraction chamber is each of the above chambers! It is a large-sized device located below the , , and numerals, and communicates with the above-mentioned extraction chamber number through a vertical passage 35 . The vertical passage 35 expands in diameter both in the front and back direction and in the left and right directions from the side of the extraction chamber to the -7- dust collection chamber 3@, ensuring a sufficiently large communication area between the extraction chamber and the dust collection chamber 3. At the bottom of the dust collection chamber 3 there is a tray 34 that can be taken out and taken out.
An air supply pipe 37 is inserted into the upper part of the dust collection chamber for final combustion.

The combustion gas extraction pipe 3t is inserted from the outside of the device into the combustion gas extraction chamber with its tip protruding, and a dust removal cap 3d is attached to the protrusion. This dust removal cap 3d is made of ceramic or other refractory material, and is an end wall 3t located between the partition wall t and the end of the take-out pipe Jl.
g, and a peripheral wall 3b including an inclined wall located on the outer periphery of the extraction pipe 31. End wall 3tα and peripheral wall 39h
is maintained at a certain distance from the take-out pipe 31 so as not to come into contact with the pipe, and a combustion gas flow opening is bored in a lower part of the peripheral wall sqh. Also, the end wall 39a of the dust removal cap 3D
A guide vane l is disposed between the shaft portion communication port IO and the partition wall F for discharging the combustion gas from the shaft communication port IO toward the outside of the combustion gas extraction chamber.

r - JP-A-58-80411 (3) Note that 4'i2, 4A3, and 141 are chamber l, respectively.
This shows the inspection window.

This device with the above configuration drives the valve lf and opens/closes the valve l.
The gas from the gas cylinder J is ignited by the spark plug H, and the flame is passed through the fuel introduction pipe 6 through the introduction pipe 4.
At the same time, when the drive device of the fuel storage hopper is activated, the caking coal-based granular fuel containing tar changes into a non-caking substance by preheating (carbonization), and the subsequent combustion occurs. will be started. That is, when the granular fuel is injected into the cylindrical body 61 of the preheating device AO together with the heating flame, the fuel becomes heated and the tar contained in the axillary fuel is gasified, and the granular fuel that was the caking substance is The fuel turns into a non-caking substance. Chemically, this change mainly corresponds to the carbonization of coal-based fuel in the pre-combustion process.In other words, the temperature of the heated flame is such that the temperature of the granular fuel inside the cylindrical body 6/ Temperature at which carbonization is carried out (200
℃~800℃). Of course, there is no problem in partially starting combustion within the cylindrical body 6/. Cylindrical body 6
1 has a constricted portion bth at the tip to prevent blowing out, so that the granular fuel can be heated effectively.

The coal-based granular fuel, whose properties have changed to non-caking in this way, is blown out from the fuel injection port 6← into the combustion chamber l, the blowhole collides with the prevention cap 13, and then from the -fire air supply pipe 13. The mixture is mixed with a vortex of air and burns in a fluid state.

In order to more reliably cause combustion in the combustion chamber I, the branch pipe /&a of the heating flame introduction pipe 16 can be opened into the combustion chamber /, as shown in FIGS. 2 and 5. The amount of ignition flame from branch pipe 74g is regulated by valve/44.

The swirling combustion gas that burns in this way in the first cylindrical combustion chamber l is then vented to the conduction lower 3m of the prevention cap 13.
The fuel enters the second cylindrical combustion chamber through the shaft communication port IJP and the peripheral communication hole ti, and continues spiral combustion. The secondary air supplied from the secondary air supply pipes t, yy in the tangential direction of the combustion chamber is effective in strengthening this vortex flow and continuing combustion.

This swirling combustion gas is finally released into the outer part of the combustion gas extraction chamber through the shaft communication port 10 of the Yotoku T and the guide vane I, and is combined with the air flow from the tertiary air supply pipe 31 to form a swirl. continues to burn.

At this time, the combustion gas ejected from the shaft communication port 10 violently collides with the end wall 3 of the dust removal cap 39 on the outside 6, but since the dust removal cap 3 is made of a heat-resistant material, it can easily be exposed to high heat. It will never be damaged. The high-temperature, high-pressure combustion gas finally enters the cap through a flow opening formed in a lower part of the dust removal cap 390 station @SO, and is taken out to the outside from the combustion gas extraction pipe 3t. Since the flow opening is drilled below the dust removal cap 3D, there is a very low possibility that combustion ash, especially heavy unburned matter, will reach the extraction pipe 3T, thus allowing clean combustion gas to be taken out. be able to.

The combustion in the combustion zone B described above is performed by burning the coal-based granular fuel whose coagulated solids have been changed to non-caked solids in the preheating zone P, so -// - Foreign matter may adhere to the combustion chamber wall. The rate at which combustion or fouling builds up is low, and therefore cases of combustion troubles occurring are extremely rare. Further, since the combustion in each of the above chambers takes place in a vortex, the agitation and floating state of the fuel can be maintained for a long time. Combustion in such a fluidized state is known to reduce the generation of NOx and 80x, thus contributing to the prevention of air pollution.

Another advantage is that low quality coal with high ash and sulfur content can be used.

The combustion ash resulting from the above-mentioned combustion is stored in a vertical passage 3 in a dust collection chamber 3 which has a sufficiently large space compared to the combustion gas extraction chamber. ; and are collected in the tray 36. In this dust collection chamber 3, fresh air from the supply pipe 37 causes final combustion of unburned substances, and the combustion gas rises and flows back into the combustion gas extraction chamber. □ It is known that when the temperature of the combustion chamber exceeds approximately SOO℃, the presence of trace amounts of water and oxygen (combustion air) causes a water gasification reaction according to the following reaction formula, making it easier for powdered coal (φ) to burn. .

H, O + O → 00 + horse 00-) -H, + O, → 00. +H,0 Therefore, in this device, each of the −, secondary, and tertiary air supply pipes/3,
29, r, 3/, as shown in FIG. 5, an on-off valve 3. Da6. Water supply pipe connected to tank 449 via duct and R! Connect 0, 3/, j, 53,
Furthermore, inspection viewing window <U, lA3. N4I- also has an opening and closing review, SS.

Water supply pipe with 56 and connected to tank 9! ? ,
31 and 39 are opened to supply each combustion chamber with a small amount of water necessary for the water gasification reaction.

Note that an appropriate number of two or more cylindrical combustion chambers may be provided in consideration of factors such as the type and particle size of the granular fuel, or the amount of heat generated.

In summary, the combustion apparatus according to the present invention has a cylindrical combustion chamber located downstream of a horizontal cylindrical combustion chamber in which coal-based granular fuel is injected and combusted.
In a combustion device equipped with a combustion gas extraction chamber with a combustion gas extraction pipe facing inside, a preheating device is provided for the coal-based granular fuel to be blown into the cylindrical combustion chamber, and this preheating device removes the tar contained in the fuel. Because it gasifies the fuel and turns it into a non-caking substance, it can prevent foreign matter from adhering to the combustion chamber wall or slow down the rate at which foreign matter accumulates, thus reducing combustion troubles. This can be prevented and the number of times the combustion chamber must be cleaned can be reduced. In particular, according to the present invention, it is possible to burn cohesive fuel, which has been difficult to use in the past, so its utility value is high. Further, the cylindrical combustion chamber and the combustion gas extraction chamber are oriented horizontally, and the combustion gas extraction pipe facing the extraction chamber is also oriented horizontally, so that it can be used as is in conventional oil burner boilers, dryers, etc.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing an embodiment of the combustion device according to the present invention, and FIGS. 5 is a system connection diagram with a partially sectional perspective view showing the fuel and other supply piping system for this combustion device, and FIG. 6 is a system connection diagram along the ■-Vl of FIG.
It is a sectional view along a line. B... Combustion zone, P... Preheating zone, llco...
・Cylindrical combustion chamber, 3...dust collection chamber, 3...combustion gas extraction house,? , f... Partition wall, 9, 10... Shaft communication port, /
44...Fuel supply pipe, is, 91. To, 3/・
...Air supply pipe, 16...Heating flame introduction pipe, Comment...Fuel storage hopper, 31...Combustion gas extraction pipe, 40...
Preheating device, 4/... cylindrical body, 63... fuel introduction pipe,
A4L...Fuel spout.

Claims (2)

[Claims] (1) A combustion gas extraction chamber with a combustion gas extraction pipe facing inside is provided downstream of the horizontally oriented cylindrical combustion chambers that communicate with each other,
In a combustion apparatus, coal-based granular fuel is blown into the most upstream cylindrical combustion chamber and combusted, and the combustion gas is taken out to the outside from the combustion gas extraction pipe. A combustion apparatus comprising a preheating device for preheating granular fuel to be charged, gasifying tar contained in the fuel, and converting the fuel into a non-caking substance. (2) The combustion device according to claim 1, wherein the preheating temperature in the preheating device is about 200 to SOO°C.