JPH0151742B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a combustion device that easily and efficiently burns a low-ash solid fuel.

(Prior art) In recent years, various fuels have been used for various purposes such as heating, bathing, and boiling water, such as coal and other solid fuels, oil, and natural gas. Lignite, petroleum coke, calciner coke, coal pitch coke, etc. are known as solid fuels with low ash, and are inexpensive and high in calories.Currently, however, the use of petroleum, which is easy to ignite and has a low flash point, is significant, but in the future The supply amount and import costs are not necessarily stable, and storage is dangerous and management costs are incurred. Therefore, low-calorie and inexpensive solid fuels such as briquettes and coal are used, which are easy and safe to handle during transportation and storage, quickly ignite, and have no risk of fire or explosion.

One type of device for burning coal or other solid fuel is to horizontally install a rostol having a plurality of ventilation slits in the combustion chamber, deposit the solid fuel at a predetermined height on the rostrum, and ignite it as appropriate. After that, the solid fuel is ignited by a means of ignition, and then the solid fuel is continuously combusted. (Jikko No. 39-36175, No. 40-
(See No. 23003). However, due to the purpose of its use, the solid fuel requires heat retention and good fire life, and if the ash content is less than 10%, the ash will fall off the shelf and fall from between the roasters. However, even when burned, the ash retains its shape without falling off the shelf, and has a heat-insulating effect.Therefore, there is a large amount of ash left after combustion, which requires time and effort to dispose of. The cost was also relatively high due to the necessity of selecting raw materials and molding.

On the other hand, there were combustion devices in the form of sealed boxes without a lostle that burned cheaper solid fuels such as firewood and old wood. (a, Utility Model Application No. 56-124714, b, same
55-131433).

As a means of igniting the above-mentioned conventional combustion devices and various fuels, Utility Model Publication No. 34-21571 and Utility Model Application Publication No. 52-55472 include embedding a heating wire in a heat-resistant disk having ventilation holes as a means of igniting charcoal briquettes. A configuration is disclosed in which the briquettes are provided under the exposed briquette support frame. There are other ways to ignite oil or gas. (Refer to Utility Model Publication No. 44-28623 and Japanese Patent Application Laid-open No. 124481/1973).

(Problems to be Solved by the Invention) The conventional low-ash solid fuel has other advantages such as low cost, but it has a high sulfur content and has a negative effect on metals when burned, so care must be taken when using it as an industrial fuel. It was used in combination with coal and in kilns for firing cement where sulfur content was not a problem. Additionally, as a fuel for general heating, it has a unique odor due to its nature, and because of its low ash content, it is prone to shelving, contrary to solid fuels with an ash content of 10% or more. The fuel falls from the rostre as it burns, and the high-temperature combustion causes cracks in the fuel, increasing its surface area, further increasing the combustion rate, and the finer combustion fuel falls from the slits in the rostre, causing its temperature to drop due to heat dissipation. The combustion stops and becomes unburned residue, which is wasted. Therefore, not only does the efficiency of fuel use decrease, but also the amount of solid fuel deposited during combustion decreases, leading to an unexpected situation where the solid fuel disappears, or the fine fuel that falls from the slit of the roaster during combustion is removed. There are disadvantages such as being forced to do extra work that is necessary. In addition, low-ash solid fuels such as coke are sprayed with water during the manufacturing process, so if drying and dehydration are insufficient, the moisture contained in the coke will become steam due to the heat of the fire and cannot be fully released. It had the disadvantage of flying and falling even further from Lostol.

Among the above-mentioned combustion devices, the closed box type type (a) without a roostor has an ash trap below the base cylinder with a cap for intake, even though the fuel used is high in ash. There is no structure that can be taken out, and in addition to the base cylinder, there is an air supply pipe with a damper directed downward from the top of the base cylinder for intake and exhaust for combustion.
This is a complicated and time-consuming configuration in which a chimney is provided, the base cylinder is closed after combustion is active, and the air supply pipe is activated. Moreover, an efficient natural intake/exhaust structure is not disclosed in the closed box type combustion apparatus described in b. Furthermore, the above-mentioned ignition means are ignition means such as charcoal briquettes, oil, gas, etc., and none of them discloses a simple ignition means for low-ash solid fuels that are high in calories and difficult to ignite. Therefore, the present invention further enhances the utilization efficiency of the low ash solid fuel to facilitate ignition, improve combustion efficiency with natural aspiration, prevent undesired burnout, and reduce the amount of unburned residue left behind. The purpose is to

(Means for Solving the Problems) In order to achieve the above object, the present invention supports a low ash solid fuel on a flat receiving plate that does not have any ventilation slits or grooves. A bottomless cylindrical body is provided which is supported on a plate and surrounds the solid fuel to form a combustion chamber, and between the lower end of the cylindrical body and the receiving plate there is an intake air that is naturally drawn in proportion to the exhaust air.
A chimney with a lid and a damper that can be opened and closed on the cylindrical body, and a chimney that forms a gap between the cylinders and the intake air.
A space adjustment cylinder is engaged with a pin and a tapered groove so that it can move up and down, and a ceramic heater in the form of a flat plate, rod, or tube, which is energized by external operation, is attached to the receiving plate in the combustion chamber or to the peripheral wall of the combustion chamber. This is what happens.

(Function) Low ash solid fuel is deposited in the combustion chamber on the receiving plate, and the fuel is ignited by the high heat generated by energizing the ceramic heater. As the fuel burns, the combustion temperature gradually rises to a high temperature, and combustion continues with natural intake through the intake air gap and the chimney.

(Example) An example of the present invention will be described in detail with reference to FIGS. 1 to 3. 1 is a low ash solid fuel with an ash content of approximately 5%
Lignite, ogalite or ash content below 1%
petroleum coke of less than 1,000 yen, and coal pitch coke, molded coke, briquette, calciner coke, etc. of the same extent as these. 2 is a receiving plate; 3 is a combustion cylinder whose inside constitutes a combustion chamber 4; it is supported on the receiving plate with an intake space 20 formed between it and the receiving plate via a plurality of legs 19 at the lower end; The low ash solid fuel is surrounded on a receiving plate. Reference numeral 5 denotes a body, which together with the combustion tube 3 constitutes a cylindrical body. Reference numeral 7 denotes a chimney whose exhaust volume is regulated by a damper 7'. 8
9 is a lid that can be opened and closed for charging fuel; 9 is a hole that supplies atmospheric air directly to the body 5 to adjust combustion; 10
is a ring that closes the hole 9.

The receiving plate 2 is mainly composed of a flat metal plate with a predetermined thickness, and a heat-insulating layer 21 is formed by pasting a heat-insulating material such as castable or heat-insulating bricks on the upper surface of the plate to a predetermined thickness. A shutter 15 for dropping the fuel or unburned residue is provided so as to be rotatable downward. 22 indicates a support leg.

The combustion tube 3 is mainly composed of a metal cylinder with a predetermined thickness, and a strong fireproof material with high heat insulation and heat retention ability is attached to the inner surface of the cylinder to form a heat insulation layer 18. is formed into a downwardly tapered surface. Therefore, the heat insulation layer 18
Due to the configuration, the lower end surface of the combustion cylinder is donut-shaped, and its center hole is located between the intake plate and the lower receiving plate.
It opens to serve as a communication port within the combustion chamber 4.
Note that the heat insulating layer 18 may be formed on a vertical wall surface. A plurality of pins 3a are protruded from the lower end of the combustion tube 3, and the pins are inserted into and engaged with tapered grooves bored at predetermined positions of the distance adjusting tube 3b fitted into the combustion tube 3.
The intake gap 20 can be widened or narrowed by rotating the gap adjusting cylinder 3a and moving it up and down. The combustion tube 3 has a circular cross section, as well as 8, 6, 5, 4, triangular, and other shapes depending on the needs and design requirements of the installation location. The distance adjusting cylinder 3a is moved up and down by the following means. Note that 11 in FIG. 1 indicates a conventional ignition material.

FIG. 2 shows a ceramic heater 12 which is an ignition means and a receiving plate. The ceramic heater 12, which has durability against high heat, is formed into an approximately ladle shape in plan view, and is set on the upper surface of the receiving plate 2, and has an electrode portion 13 thereof. ，
13 is located outside the combustion chamber 4,
This prevents damage caused by direct exposure to the high temperature atmosphere during combustion. The ceramic heater shown in Fig. 3 consists of an elongated rod or tube shape.
A plurality of the wires are attached to the surface of the heat insulating layer 18 at predetermined intervals, and each electrode portion and lead wire 13'1
3' is led out to the outside via the heat insulating layer 18 and protected, and is energized by operating a switch outside the combustion chamber. Note that the shape, size, etc. of the ceramic heater are not limited to those shown in the drawings.

The operation of the low ash solid fuel combustion device with the above configuration is as follows.

As shown by the chain line in FIG. 1, when low ash solid fuel 1 is deposited in the combustion chamber 4 on the receiving plate and the ceramic heater is energized by operating a switch, the fuel is heated by the red-hot ceramic heater and its temperature rises. As a result of thermal decomposition, volatile matter comes out of the solid and burns in the air inside the combustion chamber, and the atmospheric temperature of the combustion chamber rises.After the temperature reaches a predetermined temperature, the fuel acquires oxygen from the intake air. reaches the ignition point and begins to burn. When the fuel starts to burn and all the solids deposited become red hot and radiant heat burns at a high temperature, the solid fuel cracks and becomes fine and blown away.
Since it is supported between the combustion chamber 4 and the surrounding surface of the combustion chamber, even minute combustion does not fall outside the receiving plate and stays in the high temperature area surrounded by the receiving plate and the combustion chamber 4. Combustion continues due to the effect and the intake effect from the surrounding outside air. Along with the combustion, combustion exhaust gas is discharged through the chimney 7,
As a result, atmospheric air is drawn into the combustion chamber 4 through the intake gap 20, forming an upward airflow between the accumulated fuels.

It has been confirmed through experiments that the dimension of the intake space 20 has a large effect on the combustion of the fuel, and by setting an appropriate balance between the intake and exhaust, low ash solid fuel can be produced even if it is not stacked thickly. The fuel can be pumped vigorously, and there is no need to install any special blower device. That is, the intake interval is 20
If the temperature is too high, a large amount of cold air will flow into the combustion chamber, and the rate of heat dissipation will exceed the rate of heat generation, lowering the atmospheric temperature of the combustion chamber, which may cause the fuel to disappear.
If the dimensions of the combustion chamber are made too small, the amount of air flowing into the combustion chamber will be too small, and there is a risk that the fuel will run out or a backup fire will occur.

As the combustion continues, the amount of the low ash solid fuel 1 gradually decreases, and when it approaches the limit amount that allows continued combustion, the combustion can be further continued by opening the fuel inlet 6 and adding fuel. can. Additional input may be done either manually or mechanically. Therefore, a temperature sensing element is provided to detect the temperature of the combustion exhaust gas passing through the chimney 7, and when the temperature of the combustion exhaust gas detected by the temperature sensing element falls below a predetermined temperature, a predetermined amount of low ash solid fuel 1 is provided. By providing a supply device for supplying fuel, it is possible to reliably prevent combustion from being interrupted due to forgetting to supply fuel. When the combustion is to be interrupted, an airtight extinguisher made of a heat insulating material is provided, the shutter 15 is opened, the fuel in the combustion chamber is poured in, the shutter is covered, and the extinguisher is taken out. Alternatively, the interval adjustment tube 3b
It is sufficient to lower the intake air gap 20 and open the holes 9, 9, . . . . In addition, when petroleum coke with an ash content of 0.2% is used as a low-ash solid fuel, the amount of unburned petroleum coke on the receiving plate after combustion is approximately 10 g compared to the initial input amount of 500 g. The remaining fuel can be combusted again. Even if 500 g of petroleum coke is added several times and burned continuously, the amount of petroleum coke remaining unburned on the receiving plate is about 10 g, which hardly changes. Moreover, in this case, almost no ash was observed.

(Effects of the Invention) The present invention has the above-described configuration and operation, and supports a low ash solid fuel that causes cracks during combustion on a receiving plate that does not have slits and does not have any slits. The fuel is surrounded by a combustion chamber, and the intake air from the intake gap formed between the lower end of the cylindrical combustion chamber and the receiving plate is proportional to the exhaust air from the chimney, so the overall structure is extremely simple. Despite the structure, the fuel can be naturally and continuously combusted by the natural intake, so the fuel can be almost completely combusted without any loss, and therefore almost no ash is produced. In addition, if a small amount of ash or unburned matter remains after continuous combustion, the ash will fall off immediately by scraping it out from between the air intakes on the receiving plate, or by removing the cylindrical body from the supporting plate and tilting the receiving plate. It is convenient to be able to eliminate it. Therefore, there is no inconvenience such as in conventional closed box type combustion apparatuses where ash remains in the bottom of the combustion apparatus and there is no outlet for taking out the ash, and the lid must be removed one by one and the entire apparatus must be tilted. Low ash solid fuels, which are made into fine particles like various types of coke and required time and effort to be remolded and processed into fuels that prevent blowouts, can now be burned efficiently in their unprocessed form. Furthermore, almost complete combustion of the fuel prevents the generation of harmful gases and pollution due to ash, and has the unique effect of allowing low-cost solid fuel to be used as is. In addition, the ceramic heater used as the ignition means is easy to configure and operate.
It is heat-resistant, low-volume, and integrally attached to the combustion chamber or on the receiving plate, and it heats up to a high temperature and can easily and reliably ignite high-calorie fuel.Moreover, there is no risk of it extinguishing before ignition, and it does not require the use of conventional ignition materials. As such, it does not itself turn to ashes.

[Brief explanation of drawings]

The drawings show an embodiment of the low ash solid fuel combustion apparatus of the present invention, FIG. 1 is a longitudinal sectional view of the same, and FIG.
FIG. 3 is an enlarged plan view of a main part showing one example of the ignition means of the above device, and FIG. 3 is an enlarged longitudinal cross-sectional view of the main part showing another example of the ignition means of the above device. 1... Low ash content solid fuel, 2... Receiving plate, 3... Combustion tube, 3a... Interval adjustment tube, 4... Combustion chamber, 5... Body,
7...Chimney, 7' damper, 8...Lid, 20...Intake space.

Claims (1)

[Claims] 1. A receiving plate made of a durable, heat-resistant material such as metal of a specified thickness and having no slots, slits, etc. for supporting low ash solid fuel, and a supporting plate of the same effective quality supported on the receiving plate to support the combustion chamber. A heat insulating layer of a predetermined thickness made of heat insulating bricks or other heat insulating material is provided around the receiving plate and the combustion chamber to support and surround the low ash solid fuel, An intake space is formed between the lower end of the combustion cylinder and the receiving plate, and the combustion air can be continuously supplied in proportion to the exhaust air, and the cylindrical body is provided with a chimney having an openable and closable combustion inlet and a damper. A plurality of pins are provided protruding near the lower end, and the pins are inserted into and engaged with the tapered grooves of the distance adjustment cylinder fitted externally to the cylindrical body, and a single flat plate shape that can be energized by an externally provided operating section. A low ash solid fuel combustion device comprising a ceramic heater or a plurality of elongated ceramic heaters in the form of rods or tubes attached to a receiving plate in a combustion chamber or to the wall surface of a heat insulating layer in the combustion chamber.