JP2014095517A - Combustion furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a combustion furnace capable of keeping combustion at a temperature higher than 800°C by materializing higher temperature of primary air supplied to a combustion part, thereby promoting combustion of fluid solid fuel within the furnace.SOLUTION: The combustion furnace is of a self-combusting type and includes: a furnace body 1; an inner cylinder 2 placed inside the furnace body 1; an exhaust stack 3 passing through the inner cylinder 2 and the furnace body 1 and having its lower end placed inside the inner cylinder 2; a supply pipe 4 for supplying primary air and fluid solid fuel into the inner cylinder 2; and burner connection pipes 5, 5a. The inner cylinder 2 has a lower part opened and has at its upper part a vent hole port 23. The inner cylinder 2 is attached to the furnace body 1 while forming between the inner cylinder and the inner surface of the furnace body 1, an ascending vent hole passage 15 where combustion gas ascends and communicated with the vent hole port 23. The exhaust stack 3 has a lower end opened to an inner side of the inner cylinder 2, and has an upper side passing through the inner cylinder 2 and the furnace body 1 and opened outside. The supply pipe 4 passes through the peripheral wall of the furnace body 1 and the inner cylinder 2 and connected to them.

Description

  The present invention relates to a combustion furnace. More specifically, the present invention relates to a combustion furnace that can efficiently incinerate compost made from livestock excrement while completely burning so as not to cause malodor.

  In livestock farmers, compost is made from livestock excrement, and the farming environment is set up so that it can be used as much as possible, so that livestock excrement is efficiently processed. However, in reality, due to the lack of demand, it has been incinerated without being used as compost. Combustion furnaces used for incineration of compost and the like are mainly self-combustion type furnaces that can use compost itself as energy, and such self-combustion type combustion furnaces have been put into practical use in large-scale plants.

In the case of a large-scale plant, the equipment cost and the maintenance cost are high, and it is difficult to introduce it at the scale of general livestock farmers. Therefore, for example, a swirl type combustion furnace described in Patent Document 1 has been proposed as a self-combustion type combustion furnace that can be introduced even by relatively small customers.
The swirl type combustion furnace described in Patent Document 1 includes a cylindrical furnace body having a fuel supply port formed in an upper portion thereof, and an exhaust port for combustion gas is provided on the top plate of the furnace body. An inner cylinder forming a combustion chamber is suspended inside the enclosure, and fuel is guided to the lower inlet of the combustion chamber between the inner cylinder and the peripheral surface of the furnace body by the swirling flow of primary air supplied from the fuel supply port. A turning guideway is provided.

  The turning guide path is connected to a blower pipe that feeds fuel and primary air to the fuel supply port by a fan in a tangential direction with respect to the inner peripheral surface of the furnace body. The blower pipe is provided with a fuel inlet, and the blower pipe An ejector that speeds up the primary air sent to the interior of the engine and sucks the fuel toward the fuel supply port is provided at the bottom of the furnace body, between the bottom surface and the lower inlet of the combustion chamber, along the swirling guideway. A pyrolysis space for pyrolyzing the fuel that descends with the swirling flow is formed by the combustion gas, and an air intake for taking in secondary air from the outside is provided for the purpose of burning the pyrolysis gas in the combustion chamber. Further, the drying and pulverization of the fuel is promoted by the heat of the combustion gas.

Japanese Patent No. 4687931

However, the conventional swirl type combustion furnace has the following problems.
That is, the outside air taken in as primary air is swung through the path toward the exhaust side in the furnace and moved, and is then guided to the exhaust side as it is.
Therefore, the temperature at the initial stage of introduction of primary air is low, the combustion furnace is relatively small and the path through which the combustion gas passes to the exhaust port is short, and the flow of combustion in the furnace is small because the combustion furnace is small. Combustion temperature in the combustion chamber cannot be sufficiently increased due to the relatively small amount of fuel such as volatile solid fuel, etc., and combustion at a high temperature of 800 ° C or higher as defined in the new standard of the Dioxin Special Measures Law As a result, the use of fossil fuels has increased.
In addition, when compost fuel burns, a temperature of at least about 420 ° C. is necessary. However, since the combustion temperature does not rise sufficiently, incomplete combustion is likely to occur, and a bad odor is generated, and a combustion furnace is installed. There was a risk that the environmental load around the place would increase.

(Object of the present invention)
In the present invention, the temperature of the primary air supplied to the combustion section is made higher than that of a conventional swirl combustion furnace, and the combustion of fuel in the furnace is promoted so that a higher combustion temperature can be maintained. It is a relatively small combustion furnace that can maintain combustion at a high temperature of 800 ° C or higher as set forth in the new standards of the Special Measures Law for Dioxins, and can be introduced even by relatively small-scale customers such as general livestock farmers. However, an object of the present invention is to provide a combustion furnace capable of completely burning fuel by self-combustion.

Means taken by the present invention to solve the above problems are as follows.
(1) The present invention
A self-combustion type combustion furnace for burning a fluid solid fuel,
A furnace body that is a hollow body and has a combustion part at the bottom;
A middle cylinder inside the furnace body;
An exhaust pipe that penetrates the middle cylinder body and the furnace body from above and has a lower end on the inner side of the middle cylinder body;
An outlet facing the upper part of the middle cylinder, and a supply pipe for supplying primary air and fluid solid fuel into the middle cylinder;
Have
Between the side inner surface of the furnace main body and the side outer surface of the middle cylindrical body, a ventilation path is formed,
On the upper or upper side surface of the middle cylinder, the ventilation passage is connected to the inside of the middle cylinder, and a vent hole through which combustion gas passes is formed.
It is a combustion furnace.

(2) The present invention
A self-combustion type combustion furnace for burning a fluid solid fuel,
A furnace body that is a hollow body and has a combustion part at the bottom;
A middle cylinder inside the furnace body;
An exhaust pipe that penetrates the middle cylinder and the furnace body, and whose lower end is on the inner side of the middle cylinder,
A supply pipe for supplying primary air and fluid solid fuel into the inner cylindrical body;
Ignition means for igniting the fluid solid fuel in the combustion section;
Have
The middle cylinder is
The bottom is open, the vent is formed in the top,
Between the inner surface of the furnace body, a rising air passage that leads to the vent is formed by rising combustion gas, and is supported by the furnace body by support means,
The exhaust stack is
The lower end opens inside the middle cylinder,
The upper side penetrates the middle cylinder and the furnace body, and the upper end opens to the outside,
The supply pipe is
Penetrating the peripheral wall of the furnace body and the middle cylinder, and connected so that the outlet faces the upper part in the middle cylinder,
It is a combustion furnace.

(3) The present invention
Supplying secondary air to the lower part of the furnace body, equipped with preliminary air blowing means to wind up the accumulated combustion ash in the furnace body,
It is preferable and recommended that the preliminary blowing means includes a preliminary blowing pipe that penetrates the furnace body and has an outlet facing the furnace body.

(4) The present invention
Preheating means for heating the inside of the combustion furnace before the start of operation is provided, and the preheating means preferably includes a burner connection pipe that penetrates the furnace main body and has an outlet facing the inner cylinder.

  In the claims and this specification, the air from the outside supplied from the supply pipe into the inner cylinder by the start of operation is referred to as primary air, and the air supplied appropriately from the preliminary air blow pipe into the furnace body is secondary. Air.

(Function)
The operation of the combustion furnace according to the present invention will be described.
First, the combustion furnace is preheated using preheating means. Next, an appropriate amount of fluid solid fuel such as compost is introduced into the combustion furnace. Specifically, the fluid solid fuel is supplied from the supply pipe to the inside of the middle cylinder together with the primary air, and is stored in the combustion part of the furnace body. The fluid solid fuel in the combustion section is ignited by the igniting means, whereby the fluid solid fuel is combusted. The ignition means stops when combustion is stabilized, and self-combustion starts. The primary air is supplied from the supply pipe to the inside of the intermediate cylinder with an appropriate air volume in accordance with the self-combustion state of the fluid solid fuel.

  The primary air supplied, for example, in a tangential direction with respect to the inner surface of the intermediate cylindrical body, descends while swirling along the shape of the inner surface, exits from the lower opening of the intermediate cylindrical body, and flows through the combustion section by self-combustion. Supply oxygen to the volatile solid fuel and help combustion. Most of the combustion gas generated by the combustion (self-combustion) of the fluid solid fuel enters the inside of the middle cylinder, and is discharged outside through the exhaust cylinder. Further, a part of the combustion gas rises through the rising air passage while heating a part of the primary air that is flowing by swirling or the like, and enters the inside of the middle cylinder through the air vent.

  The mixed gas of combustion gas and primary air that has entered through the vent hole is hot, and newly exchanges heat with the primary air that has entered the inside of the middle cylinder from the supply pipe and descends to the combustion section. Heat the air. In this way, the primary air supplied from the supply pipe is heated by the mixed gas of the high-temperature combustion gas and the primary air entering from the vent at the initial stage of entering the middle cylinder and supplied to the combustion section. Is continuously performed, the combustion temperature of the fluid solid fuel is maintained at a higher temperature as compared with the conventional combustion furnace in which the primary air is not effectively heated in the initial stage of introduction. The temperature in the furnace is detected and monitored by a temperature sensor such as a thermocouple. When the temperature falls to a predetermined temperature, the fluid solid fuel is appropriately supplied from the supply pipe together with the primary air.

  As a result, it is possible to maintain combustion at a high temperature of 800 ° C. or higher as defined in the new standard of the Special Measures Law for Dioxins, and it is possible to suppress the generation of dioxins. Even a relatively small combustion furnace that can be introduced at home can provide a combustion furnace capable of completely burning a fluid solid fuel by self-combustion.

  Secondary air is supplied to the lower part of the furnace body, and a preliminary blower means for winding up the accumulated combustion ash in the furnace body is provided. The preliminary blower means has a preliminary blower pipe penetrating the furnace body and facing the outlet in the furnace body. When the preliminary blower means is operated as appropriate, for example, a small amount of air is blown to the combustion ash accumulated below the combustion section, and the combustion ash is rolled up or blown up, so that it is not contained in the combustion ash. The combustor is exposed to high temperatures in the furnace. Furthermore, since oxygen is supplied to the unburned portion by the secondary air, combustion is promoted and complete combustion is facilitated.

  As a result, the temperature of the primary air supplied to the combustion unit and the temperature of the mixed gas of the combustion gas and primary air used for heating the newly introduced primary air can be more stably maintained at a high temperature. it can. However, the preliminary air flow should be small in order to prevent the temperature in the furnace from decreasing.

  Those that have preheating means to heat the inside of the combustion furnace before the start of operation can sufficiently heat the interior of the furnace at the start of operation, so stable ignition of fluid solid fuel and continuation of combustion at the initial stage are stable. Can be done.

  The present invention maintains a higher combustion temperature by promoting the combustion of fluid solid fuel in the furnace so that the temperature of the primary air supplied to the combustion section is higher than that of a conventional swirl type combustion furnace. it can. This makes it possible to maintain combustion at a high temperature of 800 ° C. or higher, which is defined in the new standard for the Special Measures Law for Dioxins, and can suppress the generation of dioxins, and is relatively small, for example, as a general livestock farmer Even if it is a comparatively small combustion furnace which can be introduced even by a consumer, a combustion furnace capable of completely burning a fluid solid fuel by self-combustion can be provided.

The perspective view which shows one Example of the combustion furnace which concerns on this invention. The front view of the combustion furnace shown in FIG. The side view of the combustion furnace shown in FIG. The top view of the combustion furnace shown in FIG. AA sectional drawing in FIG. Explanatory drawing which showed the flow of the gas in the inside of a combustion furnace with the arrow. The graph which shows transition of the internal temperature at the time of a driving | operation of a combustion furnace. The table | surface which shows transition of the internal temperature at the time of a driving | operation of a combustion furnace. The graph which shows transition of the internal temperature at the time of the driving | running of the combustion furnace made into the comparative example by plugging the ventilation hole of a middle cylinder. The table | surface which shows transition of the internal temperature at the time of the driving | operation of the combustion furnace made into the comparative example by plugging the ventilation hole of a middle cylinder.

Embodiment

The present invention will be described in detail based on the embodiments shown in the drawings.
Please refer to FIG. 1 to FIG.
The combustion furnace B is a self-combustion type combustion furnace, and is almost entirely made of iron except for heat insulating materials 113, 123, 133, 143 and refractory concrete 114, 124, 134, 144 described later. The combustion furnace B includes a furnace body 1, a middle cylinder 2 inside the furnace body 1, and an exhaust cylinder 3 inside the middle cylinder 2.

  The furnace body 1 has a cylindrical upper cylinder 11 having flanges 111 and 112 on the entire upper and lower ends, and a cylindrical lower cylinder 12 having flanges 121 and 122 on the entire upper and lower ends. ing. The upper cylinder 11 and the lower cylinder 12 are joined by connecting a lower flange 112 of the upper cylinder 11 and an upper flange 121 of the lower cylinder 12 with bolts. A circular upper surface plate 13 is joined to the upper flange 111 of the upper tube 11 and a circular lower surface plate 14 is joined to the lower flange 122 of the lower tube 12 by bolts. A rectangular support plate 140 is attached to the lower surface of the lower surface plate 14 at four positions at equal intervals in the circumferential direction so as to partially protrude from the outer surface of the lower surface plate 14.

  On the inner surfaces of the upper cylinder 11 and the lower cylinder 12 and the upper surface plate 13 and the lower surface plate 14, heat insulating materials 113, 123, 133, and 143 having appropriate thicknesses are stretched over almost the entire surface. Further, refractory concretes 114, 124, 134, and 144 having appropriate thicknesses are stretched over almost the entire inner surfaces of the heat insulating materials 113, 123, 133, and 143, respectively. The heat insulating materials 113, 123, 133, 143 and the refractory concrete 114, 124, 134, 144 are fixed to the corresponding upper cylinder 11, lower cylinder 12, upper surface plate 13, and lower surface plate 14 by a plurality of fixtures 19. .

  The middle cylinder 2 inside the furnace body 1 is a cylinder whose lower end is open and has a lower opening 21 and whose outer diameter is slightly smaller than the inner diameter of the refractory concrete 114, 124. The edge of the lower opening 21 formed at the lower end of the middle cylinder 2 is formed so as to be slightly narrowed downward. An annular upper plate 22 is formed at the upper end of the middle cylinder 2, and a vent 23 having a structure in which the cylindrical body is suspended is formed at the circular hole edge at the center of the upper plate 22. Yes.

  The middle cylinder 2 is formed between the inner surface of the refractory concrete 124, 114 of the lower cylinder 12 and the upper cylinder 11 of the furnace body 1 and the side plate 24 of the middle cylinder 2, and the inner surface of the refractory concrete 134 of the upper surface plate 13 and the upper plate. Between the combustion gas and the primary air so as to form a rising air passage 15 that flows while rising. As shown in FIG. 6, the intermediate cylinder 2 is disposed so that the recess 160 at the tip of the latching member 16 is latched on the upper fixture 19 from above and can be easily attached and detached.

  The exhaust cylinder 3 inside the intermediate cylinder 2 has a cylindrical shape smaller in diameter than the vent hole 23, and the lower end opens slightly above the portion where the lower end is narrowed inside the intermediate cylinder 2. . The upper side of the middle cylinder 2 penetrates the center of the vent 23 of the middle cylinder 2 and the top plate 13, the heat insulating material 133 and the refractory concrete 134 of the furnace body 1 in an airtight state, and the upper end opens to the outside. The upper surface plate 13 is fixed in the vertical direction with bolts.

  At a substantially intermediate height of the lower cylinder 12 and slightly below the lower end of the middle cylinder 2, a circular grate (rooster) 17 having a diameter slightly smaller than the inner diameter of the refractory concrete 124 is provided with a plurality of supports 125 (FIG. 5). And is supported horizontally. Above the grate 17 is a combustion section 170 in which fluid solid fuel such as compost burns. Further, the lower cylinder 12 and the heat insulating material are arranged on the back side of the lower cylinder 12 in a range from the height corresponding to the grate 17 in the lower cylinder 12, that is, in a range from a position slightly higher than the grate 17 to the height of the inner surface of the refractory concrete 144. 123 and a part of the refractory concrete 124 have an ash removal lid 18 that is integrally formed to be openable and closable.

  The upper cylinder 11, the heat insulating material 113, and the refractory concrete 114 are penetrated through the upper side of the side surface of the upper cylinder 11 (almost the same height as the vent 23) and closer to the back surface, and further through the side plate 24 of the middle cylinder 2. The cylindrical supply pipe 4 is connected in the horizontal direction and in a tangential direction with respect to the inner surface of the upper part of the middle cylinder 2 so that the outlet faces the middle cylinder 2. From the supply pipe 4, primary air and fluid solid fuel such as compost are supplied into the middle cylinder 2.

  On the lower side of the side surface of the lower cylinder 12 (slightly above the inner surface of the refractory concrete 144) and closer to the back side, the lower cylinder 12, the heat insulating material 123, and the refractory concrete 124 are penetrated, and the circular auxiliary air blowing pipe 4a supplies the above-mentioned supply It is connected to a position parallel to the tube 4 and overlapping in plan view. A blower (not shown) is connected to the preliminary blower pipe 4a.

  On the upper side (a little lower than the supply pipe 4) of the side surface of the upper cylinder 11 and closer to the front surface (based on FIG. 2), the upper cylinder 11, the heat insulating material 113, and the refractory concrete 114 are penetrated. Through the side plate 24 of the cylinder 2, a circular burner connection pipe 5 is connected in the horizontal direction and tangential to the inner surface of the upper part of the middle cylinder 2. Further, on the lower side of the side surface of the lower cylinder 12 (slightly above the preliminary blower pipe 4a) and closer to the front, the lower cylinder 12, the heat insulating material 123, and the refractory concrete 124 are penetrated, and the circular burner connection pipe 5a It is connected to a position parallel to the burner connection pipe 5 and overlapping in plan view. The burner connection pipes 5 and 5a are connected to the burner connection pipes 5 and 5a together with burners (not shown) that serve as ignition means and preheating means.

  Further, a viewing window 6 is formed in the middle in the vertical direction outside the upper cylinder 11 and near the front, and a viewing window 6a is formed in the middle in the vertical direction outside the lower cylinder 12 and near the front. Yes. The viewing window 6 of the upper cylinder 11 is for the administrator to check the internal state of the intermediate cylinder 2 (such as a state where the fluid solid fuel is supplied and swirled with the primary air). The viewing window 6 a of the lower cylinder 12 is for confirming the combustion state of the fluid solid fuel in the combustion section 170 above the grate 17.

(Function)
The operation of the combustion furnace B will be described with reference to FIGS.
First, the burner connected to the burner connection pipes 5 and 5a is ignited, primary air is supplied from the supply device connected to the supply pipe 4 to the inside of the intermediate cylinder 2, and the combustion furnace B is preheated for a necessary time.

  When preheating is completed, an appropriate amount of compost, which is a fluid solid fuel, is introduced into the combustion furnace B from the supply pipe 4. Specifically, compost is supplied from the supply pipe 4 to the inside of the middle cylinder 2 together with the primary air, and is stored in the combustion section 170 on the grate 17 of the furnace body 1. The compost in the combustor 170 is ignited by a burner, and the compost burns. When compost combustion is stable, stop burner. As a result, compost self-combustion begins. In addition, after that, primary air is supplied continuously and compost is supplied intermittently as appropriate.

Refer mainly to FIG.
The primary air supplied in a tangential direction with respect to the inner surface of the intermediate cylinder 2 descends while turning along the shape of the inner surface, exits from the lower opening 21 of the intermediate cylinder 2, and burns in the combustion part. Supply oxygen to compost and help burn. Most of the combustion gas generated by combusting the compost enters the inside of the middle cylinder 2 and is discharged to the outside through the exhaust cylinder 3. Further, a part of the combustion gas rises through the ascending air passage 15 while heating a part of the primary air that is flowing by swirling or the like, and from the air vent 23 in the upper part of the middle cylinder 2. Enters the inside of the middle cylinder 2.

  The mixed gas of the combustion gas and the primary air that has entered from the air vent 23 is at a high temperature, and newly exchanges heat with the primary air that has entered the inside of the middle cylinder 2 from the supply pipe 4, and the combustion unit 170. The primary air descending to is heated. That is, the primary air supplied from the supply pipe 4 is heated by the mixed gas of the high-temperature combustion gas and the primary air that has entered from the vent 23 at the initial stage of entering the middle cylinder 2, and is supplied to the combustion unit 170. Is continuously repeated.

  Thus, the combustion temperature of compost is maintained at a higher temperature compared to a conventional combustion furnace in which primary air is not effectively heated in the initial stage of introduction. The temperature in the furnace is detected and monitored by a temperature sensor (not shown) such as a thermocouple. When the temperature falls to a required temperature, compost is supplied from the supply pipe 4 together with primary air, for example, intermittently as appropriate. The

  Further, the preliminary blast pipe 4a is operated as appropriate. When a small amount of air is supplied from the preliminary blast pipe 4a to the combustion ash accumulated under the grate 17, the combustion ash is rolled up or blown up. Thus, the unburned part contained in the combustion ash is exposed to the high temperature in the furnace. Further, since oxygen is supplied to the floating unburned portion by primary air, combustion is promoted and complete combustion is facilitated. In this manner, the temperature of the primary air supplied to the combustion unit 170 and the temperature of the mixed gas of the combustion gas and primary air used for heating the newly introduced primary air are stably maintained at a high temperature. be able to.

  Therefore, it is possible to maintain combustion at a high temperature of 800 ° C. or higher, which is defined in the new standard of the Dioxin Special Measures Act, by self-combustion of fluid solid fuel such as compost, and it is possible to suppress the generation of dioxin and, for example, general livestock A combustion furnace capable of completely burning a fluid solid fuel by self-combustion can be provided even for a relatively small combustion furnace that can be introduced even by a relatively small-scale customer such as a farmer.

With reference to FIG. 7 and FIG. 8, the transition of the internal temperature during operation of the combustion furnace B will be described.
9 and 10 show the inside when the combustion furnace is operated under the same conditions except that the vent 23 of the middle cylinder 2 is closed so that the mixed gas does not circulate through the vent 23. The temperature transition of was shown as a comparative example. This structure in which the vent is closed is a comparative experiment in which a state close to a structure using a conventional technique is formed.

  As shown in FIG. 5, the measurement point of the temperature of the combustion furnace B is slightly below the vent 23 serving as the inlet of the middle cylinder 2 (T1) and slightly above the lower opening 21 serving as the inside of the middle cylinder 2. (T2), three locations slightly below (T3) from the upper end of the exhaust tube 3 serving as the outlet of the intermediate tube 2. Moreover, it measured in three places of the equivalent location also about the combustion furnace of the comparative example.

(Combustion furnace B)
Please refer to FIG. 7 and FIG.
Preheating was started and T1 serving as the inlet of the middle cylinder 2 and T2 serving as the inside of the middle cylinder 2 reached 400 ° C. immediately after the start and exceeded 500 ° C. at the end of preheating 30 minutes later. . Moreover, in T3 used as the exit of the intermediate cylinder 2, it exceeded 400 degreeC at the time of the end of preheating.

Preheating was completed in 30 minutes from the start of preheating, and compost which was a fluid solid fuel was added. Compost was input intermittently as appropriate, and the input amount was 3.4 L / min. The burner ignited the input compost, and the burner was stopped after 35 minutes. After that, it became combustion by self-combustion.
The temperature rises to 1058 ° C from 36 minutes after the combustion has stabilized, and the temperature around 1050 ° C is maintained from 75 minutes when composting is stopped to 77 minutes later, when composting is stopped. It was.

Further, at T3, a little later than T2, the temperature rose to 1013 ° C. after 45 minutes, and the temperature around 1050 ° C. was maintained until 75 minutes when composting was stopped.
At T1, the temperature reached 920 ° C. after 35 minutes, and after 35 minutes, the burner was stopped, and then dropped to 720 ° C. after 36 minutes. Thereafter, the temperature gradually increased, and increased to 967 ° C. after 75 minutes.

After 75 minutes when the composting was stopped, the temperature dropped sharply at any of T1, T2, and T3, and after 92 minutes, each dropped to around 400 ° C.
Thus, according to the combustion furnace B, it was also confirmed that the self-combustion of compost in the combustion section could be maintained at a temperature exceeding 800 ° C., which is defined in the new standard of the Dioxin Special Measures Law, and there was no bad odor in the exhaust. It was.

(Comparative combustion furnace)
Please refer to FIG. 9 and FIG. In the following, for convenience, the same reference numerals as those of the respective parts of the combustion furnace B are given for explanation.
Preheating is started, and at T1, which is the inlet of the intermediate cylinder 2, T2 which is the inside of the intermediate cylinder 2, and T3 which is the outlet of the intermediate cylinder 2, it reaches around 400 ° C. immediately after the start, and 30 minutes At the end of the subsequent preheating, the temperature rose to around 500 ° C.

  Preheating was completed in 30 minutes from the start of preheating, and compost which was a fluid solid fuel was added. As with the combustion furnace B, compost was input intermittently as appropriate, and the input amount was 3.4 L / min. The burner ignited the input compost, and the burner was stopped after 35 minutes. After that, it became combustion by self-combustion.

  The temperature rose to 981 ° C. at T2 and increased to 973 ° C. at T3 from 36 minutes after the combustion was stabilized. However, after that, the temperature continued to fall, and the temperature dropped below 800 ° C. after 45 minutes at T3 and after 48 minutes at T2. And at the time of 70 minutes progress, T2 fell to 629 degreeC and T3 fell to 687 degreeC. In addition, about T1, after showing the peak at 730 degreeC at the time of 35 minutes progress, after the burner stop, it fell rapidly to the vicinity of 200 degreeC, and became 70 degreeC at the time of 70 minutes progress.

In addition, when 71 minutes elapsed when the composting was stopped, T2 rapidly decreased to 365 ° C., T3 rapidly decreased to 393 ° C., T1 also decreased to 180 ° C., and thereafter gradually decreased.
Thus, according to the combustion furnace of the comparative example, it is difficult to interrupt the self-combustion of compost in the combustion part at an early stage of 800 ° C., which is defined in the new standard of the Dioxin Special Measures Law, and to maintain it at a temperature exceeding 800 ° C. there were. It was also confirmed that the exhaust had a bad odor.

  Note that the terms and expressions used in this specification are merely explanatory and are not limiting at all, and terms and expressions equivalent to the features described in this specification and parts thereof. There is no intention to exclude. Further, it goes without saying that various modifications are possible within the scope of the technical idea of the present invention.

B Combustion furnace 1 Furnace main body 11 Upper cylinder 111, 112 Flange 113 Thermal insulation material 114 Refractory concrete 12 Lower cylinder 121, 122 Flange 123 Thermal insulation material 124 Refractory concrete 125 Support tool 13 Upper surface plate 133 Thermal insulation material 134 Refractory concrete 14 Lower surface plate 140 Support plate 143 Heat insulating material 144 Refractory concrete 15 Climbing passage 16 Latching member 160 Recessed portion 17 Grate 170 Combustion portion 18 Lid for ashing 19 Fixing tool 2 Middle cylinder 21 Lower opening portion 22 Upper plate 23 Vent 24 24 Side plate 3 Exhaust tube 4 Supply pipe 4a Preliminary ventilation pipe 5, 5a Burner connection pipe 6, 6a Viewing window

Claims (4)

A self-combustion type combustion furnace for burning a fluid solid fuel,
A furnace body that is a hollow body and has a combustion part at the bottom;
A middle cylinder inside the furnace body;
An exhaust pipe that penetrates the middle cylinder body and the furnace body from above and has a lower end on the inner side of the middle cylinder body;
An outlet facing the upper part of the middle cylinder, and a supply pipe for supplying primary air and fluid solid fuel into the middle cylinder;
Have
Between the side inner surface of the furnace main body and the side outer surface of the middle cylindrical body, a ventilation path is formed,
On the upper or upper side surface of the middle cylinder, the ventilation passage is connected to the inside of the middle cylinder, and a vent hole through which combustion gas passes is formed.
Combustion furnace. A self-combustion type combustion furnace for burning a fluid solid fuel,
A furnace body that is a hollow body and has a combustion part at the bottom;
A middle cylinder inside the furnace body;
An exhaust pipe that penetrates the middle cylinder and the furnace body, and whose lower end is on the inner side of the middle cylinder,
A supply pipe for supplying primary air and fluid solid fuel into the inner cylindrical body;
Ignition means for igniting the fluid solid fuel in the combustion section;
Have
The middle cylinder is
The bottom is open, the vent is formed in the top,
Between the inner surface of the furnace body, a rising air passage that leads to the vent is formed by rising combustion gas, and is supported by the furnace body by support means,
The exhaust stack is
The lower end opens inside the middle cylinder,
The upper side penetrates the middle cylinder and the furnace body, and the upper end opens to the outside,
The supply pipe is
Penetrating the peripheral wall of the furnace body and the middle cylinder, and connected so that the outlet faces the upper part in the middle cylinder,
Combustion furnace. Supplying secondary air to the lower part of the furnace body, equipped with preliminary air blowing means to wind up the accumulated combustion ash in the furnace body,
The preliminary blower means includes a preliminary blower pipe that penetrates the furnace body and has an outlet facing the furnace body.
The combustion furnace according to claim 1 or 2. Preheating means for heating the inside of the combustion furnace before the start of operation, the preheating means includes a burner connection pipe that penetrates the furnace body and has an outlet facing the inner cylinder.
The combustion furnace according to claim 1, 2 or 3.

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