JPH07310914A - Incinerator - Google Patents

Abstract

PURPOSE:To provide an incinerator which is constituted in such a manner that, in a cylindrical secondary combustion chamber, a high temperature required for annihilation of toxic gas and sterilization and extension of a residence time of gas in a furnace are provided and cavitation of combustion the center of which is brought into an unburnt state is prevented from occurring. CONSTITUTION:Formation of an incinerator is such that a secondary combustion chamber 2 is formed in the shape of a lateral long cylinder and a stabilizing burner 33 is arranged in the secondary combustion chamber 2 at the central part of a base end, to which a flue 21 extending from a primary combustion chamber 1 is opened, in a state to point in the direction of the axis of a tip, In the incinerator, the secondary combustion chamber 2 is formed in such a shape that the inside diameter of a cylindrical shape is gradually decreased toward a tip. A tertiary combustion chamber 3 widely expanded is arranged in succession to a throttle outlet 23, a flue 31 to a scrubber 4 is opened to the tertiary combustion chamber 3, and a number of air injection nozzles 29 are opened in a scattered state to the inner peripheral surfaces of the secondary combustion chamber 2 and the tertiary combustion chamber 3. Further, to promote complete combustion, the inner peripheral surfaces of the secondary combustion chamber 2 and the tertiary combustion chamber 3 are formed of ceramic 30 having oxidation catalytic action.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an incinerator suitable for treating plastic-containing wastes, especially medical wastes.

[0002]

2. Description of the Related Art When a high-calorie polymer waste such as plastic or rubber is incinerated, the high heat of combustion easily damages the furnace. In addition, since it is difficult to completely burn the waste as it is without pollution, the primary combustion chamber that burns the waste and the secondary combustion that completely burns the incomplete combustion gas generated in the primary combustion chamber by the auxiliary burner Attempts have been made to complete the furnace by dividing it into a chamber and suppressing combustion (Japanese Patent Laid-Open No. 149525/1993, etc.). In particular, in the incineration of medical waste, such a furnace structure having a secondary combustion chamber is adopted because a large amount of polymer waste is contained and it is necessary to sterilize by complete combustion. -449
(See Japanese Patent No. 13). In addition, the secondary combustion chamber has a room shape and a tubular shape.

Medical waste discharged from the hospital includes dialyzer, catheter, blood bag, transfusion set, syringe,
Needles, surgical gloves, disposable diapers, etc., which are further classified into papers 30.8%, fibers 21.0%, and plastics 37.6% (in the case of Kyoto University Hospital). Therefore, incineration of medical waste uses the incinerator having the secondary combustion chamber as described above, but a furnace structure having a long in-furnace gas retention time is required so as to effectively act on sterilization. In this regard, the gas residence time in the furnace may be extended by passing the gas while alternating the porous ceramic plates (see Japanese Patent Laid-Open No. 2-4106).

[0004]

In the incineration of medical waste, in particular, the administration of administrative instructions is required in order to eliminate harmful gases such as hydrogen chloride gas and dioxin and to completely sterilize AIDS virus and hepatitis virus. According to the voluntary regulations of traders, efforts are made to keep the gas residence time in the furnace for 2 seconds or more and the temperature near the furnace discharge port (a part corresponding to the secondary combustion chamber or the tertiary combustion chamber) to 850 ° C or more. Looking at the conventional incinerator from this point of view, regarding the secondary combustion chamber, if it is a room shape, it is suitable for extending the residence time of gas, but the residence time is not uniform, and temperature control is difficult. , It is easy to get the required temperature or to damage the furnace at high temperature. On the other hand, in the case of the cylindrical shape, the flame of the auxiliary combustion burner is injected in the axial direction, and at that time, the gas is easily mixed with air in the cylindrical shape and a spiral flow is generated, so that the complete combustion is caused. Since high temperature is easily obtained and heat is not accumulated, it is easy to control the temperature, but there is a drawback that it is not possible to take a long gas residence time in the furnace. However, the cylindrical shape is rather excellent because the uniformity of the gas residence time in the furnace can be obtained and the constant high temperature can be obtained relatively, though it is not long.

In the cylindrical secondary combustion chamber, the high temperature required for extinguishing harmful gases and sterilization can be obtained as described above.
From a strict point of view, in the center of the spiral flow of gas, a so-called cavity with incomplete mixing with air occurs (called a cavernization phenomenon of combustion), where there is a low temperature due to incomplete combustion, so the infectious bacteria When it passed there, there was a risk that it would not be killed and would be discharged into the atmosphere, resulting in incomplete sterilization. Further, as a means for taking a long gas residence time in the furnace, as described above, when gas is passed while the ceramic perforated plates alternate, it is isolated from the auxiliary combustion burner there and causes a decrease in temperature. Hard to achieve.

According to the present invention, from the above-mentioned circumstances, in the cylindrical secondary combustion chamber, the high temperature required for extinguishing and sterilizing the toxic gas and the extension of the gas retention time in the furnace are obtained, and at the same time, the combustion is performed. The object of the present invention is to provide an incinerator in which the hollowing phenomenon of is eliminated.

[0007]

In order to achieve the above object, the present invention forms a secondary combustion chamber, to which incomplete combustion gas is supplied from the primary combustion chamber, in a laterally elongated cylindrical shape, and performs secondary combustion. In an incinerator equipped with an auxiliary combustion burner in the center of the base end where the flame passage from the primary combustion chamber opens, the secondary combustion chamber has a cylindrical inner diameter that gradually advances toward the tip. It is formed in a small throttle shape, and a tertiary combustion chamber that expands widely after the throttle outlet at the tip is provided, a flame passage to the scrubber is opened in the tertiary combustion chamber, and the inner peripheral surfaces of the secondary combustion chamber and the tertiary combustion chamber A large number of air outlets were scattered and opened to form an incinerator.

In addition, in order to promote complete combustion, the inner peripheral surface of the secondary combustion chamber may be overlaid with a ceramic having an oxidation catalytic action.

[0009]

[Operation] Since the incinerator is configured as described above, in the secondary combustion chamber, the flame of the auxiliary combustion burner is injected to its central axis, but the inner diameter becomes smaller as it goes in the injection direction. Therefore, the incomplete combustion gas from the primary combustion chamber is squeezed to a high temperature and a concentration suitable for combustion, thereby promoting combustion. In addition, since the gas that is not discharged from the throttle outlet is reversed to the surroundings because it is off the center, and it merges with the injection flow in the center again from the base end and is discharged, the gas accumulation in the furnace in the secondary combustion chamber Time doubles. Moreover, since air is taken in from the ejection port on the inner peripheral surface of the furnace during the reversal flow, the mixing of the air is improved, and it is taken into the central part and promotes complete combustion in the central part. No hollowing phenomenon occurs.

The tertiary combustion chamber is intended to reduce the impact of gas pressure and high heat applied to the scrubber, but its expanded structure allows the generation of such a gas flow in the secondary combustion chamber, and the primary combustion is also possible. Relieves the reaction pressure of gas toward the chamber. Further, even if the combustion remains in the secondary combustion chamber, the unburned gas is completely combusted without remaining. In other words, here, the complete combustion is banished.

[0011]

Embodiments of the present invention will now be described with reference to the drawings.

The incinerator is constructed by arranging a primary combustion chamber 1, a secondary combustion chamber 2 and a tertiary combustion chamber 3, and a scrubber 4 in sequence in a clockwise order in order to achieve compactness (FIG. 1).
, The arrangement is shown in a line), and a common air supply device 5 is provided on the combustion chambers 1, 2, 3 side. Combustion chambers 1, 2, 3
The overall furnace structure is of the air jacket type, and the air sent by the air supply device 5 is jetted from the inner surface of each chamber through the cavity between the air supply device 5.
Reference numeral 8 denotes a jacket in the secondary combustion chamber 2 and the tertiary combustion chamber 3.

The lower part of the primary combustion chamber 1 is a dry distillation chamber 9 for polymer waste (assuming 10,000 Kcal / kg), and the upper part is for completely burning general waste (assuming 5,000 Kcal / kg). A direct combustion chamber 11 for incomplete combustion is provided, and a rostrut 13 is interposed therebetween. Further, the dry distillation chamber 9 and the direct combustion chamber 11 are respectively provided with waste material inlets 15 and 16, and an opening / closing lid is attached to each in a sealable manner. The direct combustion chamber 11 has a cylindrical shape, and the ignition burner 17 and a large number of air ejection ports 20,
.. are provided in the direct combustion chamber 11 and the air jets 20 are obliquely arranged in the circumferential direction, so that a cyclone whirlwind occurs in the room, and along with the momentum, gas is emitted from the flame passage 21 at the upper end. It is discharged to the secondary combustion chamber 2.

In operation, in the primary combustion chamber 1, the supply of air by the air supply device 5 is basically considered to be the direct combustion chamber 11. However, in consideration of the above-mentioned assumed value of calories, the air is divided into two parts. ., The dry distillation chamber 9 was also provided with air ejection ports 22, 22 ,. Therefore, by design, it is possible to burn the polymer waste even in the dry distillation chamber 9.
Normally, the closed state of the jet outlets 22.22, ... Is kept, and even if so, general waste is burned by the heating of the ignition burner 17 in the direct combustion chamber 11, The heat heats the polymer waste in the lower carbonization chamber 9 mainly by radiant heat for carbonization. The incomplete combustion gas generated by the carbonization is sucked by the cyclone whirlwind and supplied to the secondary combustion chamber 2. At this time, a part of the secondary combustion chamber is completely combusted while passing through the direct combustion chamber 11, but the conditions such as concentration, air, heat, etc. required for the entire combustion are insufficient, so that part of the complete combustion is escaped. 2 is the supply amount. Then, in the secondary combustion chamber 2, complete combustion is achieved by satisfying the conditions.

The secondary combustion chamber 2 and the tertiary combustion chamber 3 are horizontally long and have an integral cylindrical shape. However, the secondary combustion chamber 2 has a booster mechanism that appears in a rocket with a change in internal diameter. Is formed in a throttle shape or a conical shape that gradually narrows from the base end to the middle portion, and the throttle outlet 23 at the tip is a short cylinder shape and opens into the wide tertiary combustion chamber 3. Further, the ceramics 30 having an oxidation catalytic action are thickly applied to the inner surfaces of the secondary combustion chamber 2 and the tertiary combustion chamber 3, so that the inner peripheral surfaces thereof are overlaid. Further, it may be mixed in the refractory material 28. The ceramic 30 includes, for example, vanadium titanium, which is sold as a water-soluble paint.
Carbon (trade name; Thermo Mirror Paint, manufactured by Nippon Kagaku Engineering Co., Ltd.) can be effectively used. Further, innumerable air outlets 29, 29, ... Are opened in the inner peripheral surfaces of the secondary combustion chamber 2 and the tertiary combustion chamber 3.

An auxiliary combustion burner 33 for promoting combustion is incorporated at the base end of the secondary combustion chamber 2 and is directed toward the tip end. On the other hand, since the inner peripheral surface of the secondary combustion chamber 2 is a slope whose inner diameter gradually decreases, the flame heat of the auxiliary combustion burner 33 is directly radiated to the ceramic 30 on the inner peripheral surface to heat the inner peripheral surface (the inner peripheral surface). Has a tendency to be directly subjected to the flame of the auxiliary combustion burner 33), so that the oxidation catalytic action is strongly exerted and the combustion of the incomplete combustion gas is promoted. Further promoting factors include a gas compression effect and a gas reversal effect.

Regarding the gas compression effect, when the secondary combustion chamber 2 has a throttle shape in which the inner diameter becomes gradually narrower toward the throttle outlet 23, when the injection flame of the burner 33 is injected toward the throttle outlet 23, the gas is throttled. It is compressed to a high temperature and a concentration at which it easily burns toward the outlet 23. Regarding the gas reversal effect, due to such a throttle shape of the secondary combustion chamber 2, the gas is accelerated at the center by the momentum of the burner 33 to accelerate the speed, and the cylinder exits at the throttle outlet 23. The gas deviated from the center cannot be completely exhausted from the throttle outlet 23, is inverted to the surrounding as shown by the arrow, returns to the base end portion, is sucked by the center gas, and is then discharged as the center gas from the throttle outlet 23. During that time, air from the jet ports 29, 29, ... Is mixed and complete combustion is performed by doubling the residence time in the high heat space. The residence time of the gas in the secondary combustion chamber 2 was 0.5 seconds, which was far more than 0.2 seconds in the conventional incinerator (the secondary combustion chamber was cylindrical). The residence time could be achieved. In addition, the contact area with the inner peripheral surface is increased at the time of reversal, and it is easy to receive an oxidation catalyst action. In addition, since air is mixed from the ejection ports 29, 29, ... At the time of reversing, the inversion of the same gas will never be repeated.

The tertiary combustion chamber 3 has an expanded shape in order to obtain such an inverted gas flow in the secondary combustion chamber 2 and to obtain a residence time of gas, and complete combustion is completed here. Even if the gas has a residue in the combustion, the gas is burned, and the gas is reduced in pressure and heat and discharged from the flame passage 31 to the scrubber 4. In addition, due to the presence of this expanded tertiary combustion chamber 3, in the primary combustion chamber 1, the charging port 1
It is possible to prevent the generation of reaction pressure that blows off the blow pieces 5, 16.
A jet nozzle 26 of water is opened in the flame passage 31, so that the gas in the tertiary combustion chamber 3 is cooled and decompressed with it so that the gas in the tertiary combustion chamber 3 is discharged into the scrubber 4 without any inconvenience. Be seen. The scrubber 4 collects dust and residual toxic gas by jetting water, but is used by purifying and neutralizing used water. 32
Is a circulation neutralization device, and 34 is a water spray nozzle.

The air supply device 5 is in the form of an air tank by a compressor and supplies air to the combustion chambers 1, 2 and 3 while compressing and storing the air. Can be quickly met, and this also skillfully controls the combustion and temperature in each combustion chamber 1, 2, 3. Regarding the temperature during operation, 6 in the dry distillation chamber 9
00-650 ° C, 800-850 ° in the direct combustion chamber 11
C, the temperature of the secondary combustion chamber 2 was 900 to 950 ° C, and the temperature of the tertiary combustion chamber 3 was 800 to 850 ° C, and the safe temperature for sterilization could be secured in the secondary combustion chamber 2 and the tertiary combustion chamber 3.

[0020]

As described above, according to the incinerator of the present invention, in the secondary combustion chamber, the inner diameter becomes smaller as it goes in the flame injection direction of the auxiliary combustion burner. The incompletely combusted gas from is squeezed to a concentration and high temperature suitable for combustion, and a reversing flow of gas to the surroundings is generated, and the air from the jet is mixed during the reversing, promoting complete combustion and reversing. High temperature required for extinction of toxic gas and sterilization due to flow and complete combustion, and extension of gas residence time in the furnace are both obtained. Moreover, air is taken into the center by reversing flow and hollowing phenomenon of combustion at the center Since it does not occur, it is suitable not only for the incineration of general polymer wastes, but in particular for the incineration of medical wastes without odor,
It is extremely effective in making it harmless.

Due to the expanded structure of the tertiary combustion chamber, not only the impact of gas pressure and gas heat on the scrubber is alleviated, but also the complete combustion of gas is achieved without being performed.
Not only does it allow a reverse gas flow to occur in the secondary combustion chamber, but it also safely relaxes the reaction pressure of the gas that accompanies the flame of the auxiliary burner.

In addition, when the inner peripheral surface of the secondary combustion chamber is built up by the ceramic having the oxidation catalytic action (claim 2), the flame of the auxiliary combustion burner is made of the ceramic due to the throttle shape of the secondary combustion chamber. As a result of direct heating and effective and powerful oxidation catalysis on the gas in the reverse flow, complete combustion of the gas is ultimately achieved.

[Brief description of drawings]

FIG. 1 is an explanatory sectional view showing an incinerator according to the present invention in the order of gas paths.

FIG. 2 is an enlarged sectional view of a secondary combustion chamber.

[Explanation of symbols]

 1 Primary Combustion Chamber 2 Secondary Combustion Chamber 3 Tertiary Combustion Chamber 4 Scrubber 21 Flame Trail 23 Throttle Exit 29 Air Jet 30 Ceramic 31 Flame Trail 33 Burning Burner

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display area F23J 15/04

Claims (2)

[Claims] 1. A secondary combustion chamber 2 to which incomplete combustion gas is supplied from the primary combustion chamber 1 is formed in a horizontally long cylindrical shape, and a flame passage 21 from the primary combustion chamber 1 is formed in the secondary combustion chamber 2. In an incinerator equipped with an auxiliary combustion burner 33 in the axial direction of the base end portion that opens, the secondary combustion chamber 2 is formed into a throttle shape in which the inner diameter of its cylindrical shape gradually decreases toward the front end. Squeeze outlet 2
3 is provided with a tertiary combustion chamber 3 that expands widely, a flame passage 31 to the scrubber 4 is opened in the tertiary combustion chamber 3, and a large number of air is provided on the inner peripheral surfaces of the secondary combustion chamber 2 and the tertiary combustion chamber 3. An incinerator characterized by having spouts 29, 29, ... Opened in a scattered manner. 2. The incinerator according to claim 1, wherein the inner peripheral surface of the secondary combustion chamber 2 is built up by the ceramic 30 having an oxidation catalytic action.