JPH07101087B2 - Waste treatment equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial field of application The present invention is used for treating wastes such as food waste, combustible waste, and waste urine generated at home or in business.

2. Description of the Related Art There are two types of conventional waste treatment devices: a mechanical treatment device called a disposer and a combustion type treatment device called an incinerator. However, these devices have major drawbacks such as clogging of sewers, smoke and odor, and environmental pollution.

Therefore, in order to solve these problems, a waste treatment device applying microwaves has been proposed. This device will be described with reference to FIG.

In FIG. 3, a waste storage unit 2 is installed inside the combustion chamber 1, and the waste 3 is stored in the waste storage unit 2. The combustion chamber 1 and the magnetron 4 are connected by a waveguide 5, and a microwave transparent body 6 is provided at a connection portion between the combustion chamber 1 and the waveguide 5 to prevent combustion gas from entering the waveguide 5. Prevents and protects magnetron 4.

Then, the microwave radiated from the magnetron 4 is supplied to the combustion chamber 1 through five waveguides. The microwave emitted to the combustion chamber 1 is received by the waste 3, and the energy of the microwave is converted into heat to dry, burn and incinerate the waste 3.

In addition, the combustion chamber 1 has a plurality of primary air ports 7 and a plurality of 2
A secondary air port 8 is provided, and combustion air sent from a blower (not shown) is branched into primary air 9 and secondary air 10, which are burned from the primary air port 7 and secondary air port 8, respectively. Supply to chamber 1. A catalyst chamber 11 is provided downstream of the combustion chamber 1, and the catalyst 12, the filter 13, the catalyst heating heater are provided in the catalyst chamber 11.
14 are stored, and the combustion gas is purified by the catalyst 12 into clean exhaust gas, which is discharged from the exhaust stack 15.

The burning amount of waste is determined by the output of the magnetron, and by controlling the output of the magnetron, the burning of the waste can be controlled.

Problems to be Solved by the Invention However, such a conventional waste treatment device has the following problems.

The electric field distribution in the combustion chamber is adjusted so that the microwave generated from the magnetron concentrates the electric field on the waste placed in the combustion chamber. As long as the waste contains water, all the microwaves will be absorbed by the water,
Once the waste is completely dry, the microwave heats the waste, generating flammable gases from the waste while promoting carbonization of the waste. The flammable gas is ignited to start combustion. Therefore, before the flammable gas is ignited or before the temperature in the combustion chamber rises, combustion is likely to be incomplete, and HC and CO are generated. Therefore, a catalyst is provided downstream of the secondary combustion chamber to purify HC and CO that are generated at this time and discharge them as clean combustion gas. For this purpose, it is necessary to provide a preheating time, raise the temperature of the catalyst by heating means such as a heater to a temperature at which the catalyst becomes active, and then start combustion. However, once the combustion starts, the temperature of the catalyst tends to become high because the hot combustion gas passes through the catalyst, so that the catalyst becomes very hot if the catalyst heating means is operated, and the catalyst becomes very hot. The problem arises of shortening the life of the.

The present invention provides a waste treatment device having a simple structure and extending the life of the catalyst.

Means for Solving the Problems A combustion chamber is divided into a primary combustion chamber and a secondary combustion chamber by a microwave attenuator, and combustion air is divided into a primary combustion chamber and a secondary combustion chamber. And a waste storage unit provided in the primary combustion chamber, the primary combustion chamber and the magnetron are connected by a waveguide, and the secondary air located downstream of the primary combustion chamber Heating means is provided in the supply path, a catalyst is provided downstream of the secondary combustion chamber, means for detecting the temperature of the catalyst is provided, and the heating amount of the heating means is controlled by a signal from the catalyst temperature detecting means. .

Action The action of this technical means is as follows.

Store the waste in the waste storage section in the combustion chamber. In this state, the heating device provided in the secondary combustion chamber is energized and the secondary air is supplied to heat the catalyst with the secondary air preheated to a high temperature. At this time, since the wall surface of the secondary combustion chamber is also heated, the temperature inside the secondary combustion chamber is maintained at a high temperature. Therefore, the moisture generated in the initial stage of the treatment does not condense in the secondary combustion chamber, and the corrosive gas melts into the dew condensation water to form nitric acid or sulfuric acid.
It is possible to prevent corrosion of the wall surface of the next combustion chamber. When the combustion chamber is irradiated with microwaves after the catalyst reaches the activation temperature, all the microwaves are absorbed by the water contained in the waste, the water in the waste is evaporated, and the waste is rapidly dried. After the waste is completely burned, the microwave heats the waste, generating combustible gas from the waste while promoting carbonization of the waste. Then, the combustible gas generated from the waste material is ignited by the ignition device provided in the secondary combustion chamber, and flame combustion is performed in the secondary combustion chamber. In the present invention, since the heating device is provided in the secondary air chamber provided on the outer periphery of the secondary combustion chamber, even if moisture or corrosive gas is generated from raw garbage, the heating device can generate the gas into these gases. Since the catalyst can be heated without being exposed,
The durability of the heating device can be improved. When the combustion is stabilized in the secondary combustion chamber, the catalyst becomes hot due to the heating amount of the heating device and the heating value of the combustion gas. When the catalyst temperature exceeds the set temperature, stop the operation of the heating device,
Only the heat of combustion of the waste keeps the catalyst temperature above the activation temperature. Then, as combustion progresses, the residual amount of waste decreases, it becomes impossible to maintain the catalyst above the activation temperature only by the heat of combustion of the waste, and when the catalyst temperature falls below the set temperature again, the operation of the heating device is restarted, Prevents the catalyst from falling below the activation temperature.

For this reason, the catalyst is not used unnecessarily in a high temperature state, and the life of the catalyst can be dramatically improved.

Embodiment One embodiment of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, the combustion chamber is divided into a primary combustion chamber 17 and a secondary combustion chamber 18 by a microwave attenuation unit 16, a waste storage unit 19 is installed inside the primary combustion chamber 17, and a waste 20 is disposed. set. The catalyst 23 is heated by starting the supply of combustion air and the energization of the catalyst heating heater 22 provided in the secondary air chamber 21. At this time, the wall surface of the secondary combustion chamber is also heated.
The temperature in the next combustion chamber 18 will be maintained at a high temperature. For this reason, the moisture generated in the initial stage of the treatment does not condense in the secondary combustion chamber 18, and the corrosive gas melts into the condensed water to form nitric acid or sulfuric acid, which corrodes the wall surface of the secondary combustion chamber. Can be prevented. When the temperature of the catalyst 23 rises to the activation temperature or higher, the magnetron 24 starts to be energized.

2450MHz microwave is transmitted from magnetron 24,
It is irradiated through the waveguide 25 into the primary combustion chamber 17. In the primary combustion chamber 17, the electric field distribution in the primary combustion chamber 17 is adjusted so that the electric field is concentrated on the waste material 20 placed in the waste container 19. For this reason, all microwaves are absorbed by the waste 20, the water content of the waste 20 is evaporated, and the waste 20 is rapidly dried. At this time, the permittivity of water contained in the waste 20 is much larger than the permittivity of the components contained in the other waste 20, so that the moisture contained in the waste 20 is totally absorbed. . Therefore, after the waste 20 is completely dry, microwaves begin to heat the waste 20.

When the waste 20 reaches a high temperature to some extent, carbonization of the waste 20 starts while generating a flammable gas from the waste 20. This combustible gas is mixed with the primary air 27 supplied from the primary air port 26 and supplied to the secondary combustion chamber 18. The combustible air-fuel mixture sent to the secondary combustion chamber 18 is ignited by the igniter 28 provided in the secondary combustion chamber 18 and supplied from the secondary air port 29.
Secondary combustion is performed by mixing with the secondary air 30. In the present invention, since the heating device is provided in the secondary air chamber 21 provided on the outer periphery of the secondary combustion chamber 18, even if moisture or corrosive gas is generated from raw dust, the catalyst heating heater Since the catalyst can be heated without exposing 22 to these gases, the durability of the catalyst heating heater 22 can be improved. A microwave attenuator 16 such as punching metal is provided at the boundary between the primary combustion chamber 17 and the secondary combustion chamber 18 to prevent microwaves from entering the secondary combustion chamber 18. Therefore, the igniter 27 can ignite the combustible air-fuel mixture without being affected by receiving microwaves and causing arcing. The combustion gas is purified by the catalyst 23 and then discharged from the waste cylinder 31.

After that, the waste 20 receives microwaves from the magnetron 24, promotes carbonization while generating combustible gas, and performs secondary combustion until the waste 20 is completely carbonized and no combustible gas is generated. Flame combustion continues in chamber 18.

The temperature of the catalyst 23 rises as the combustion amount increases. By detecting the temperature rise of the catalyst 23 and controlling the energization amount of the heater 22 for heating the catalyst, the temperature of the catalyst 23 is prevented from becoming high. Therefore, in the present invention, a catalyst temperature detecting section 32 is provided in the secondary combustion chamber 18 upstream of the catalyst 23 so that the temperature of the catalyst 23 can be detected. Here, the temperature detection unit 32 is a thermocouple, an optical sensor, or the like that can detect the combustion state by detecting temperature, light, and the like.

For example, a case where a thermocouple is used for the temperature detecting unit 32 will be described with reference to FIG.

FIG. 2 shows a signal (temperature in the case of a thermocouple) from the temperature detecting section 32 after the catalyst heating heater 22 is energized. During preheating, the heater 22 for heating the catalyst is energized, and the secondary air 30 is supplied to the secondary air chamber 21. Here, the temperature of the secondary air 30 is raised by the heater 22 for heating the catalyst and 2
It is supplied to the next combustion chamber 18. The catalyst 23 is heated by the preheated secondary air 30. Then, the temperature becomes almost constant at a temperature determined by the amount of secondary air and the capacity of the heater 22 for heating the catalyst (FIG. 2). Here, when the magnetron 24 is energized, the water contained in the waste 20 absorbs the microwaves and dries rapidly while evaporating the water. At this time, the temperature of the detection unit 32 drops due to the effect of the evaporated water, and becomes substantially constant at a temperature determined by the boiling point of water and the temperature of the secondary air (Fig. 2). When the drying of the waste 20 is completed, the waste 20 generates combustible gas and promotes carbonization. The generated combustible gas is purified by the catalyst 23, and the temperature of the catalyst 23 rises due to heat generated during purification. When the concentration of the combustible gas in the secondary combustion chamber 18 becomes in the combustible range, the igniter 28 ignites and 2
Combustion is started in the next combustion chamber 18. Therefore, the temperature of the catalyst 23 rapidly rises with the formation of flame (Fig. 2). Here, when the temperature of the catalyst 23 reaches the set temperature, the energization of the catalyst heating heater 22 is stopped by the signal from the temperature detection unit 32.

After that, the temperature of the catalyst 23 is determined by the combustion amount of the waste, that is, the combustion amount according to the output of the magnetron 24. Therefore, by controlling the output of the magnetron 24 to control the combustion amount of the waste 20 to be constant, the temperature of the catalyst also becomes constant (Fig. 2). As the combustion progresses further and the amount of combustible gas generated from the waste 20 decreases, it becomes difficult to keep the amount of combustion of the waste constant even if the capacity of the magnetron 24 is maximized. Gradually decreases. When the temperature of the catalyst 23 becomes equal to or lower than the set temperature, the temperature of the catalyst 23 can be prevented from lowering and the activity of the catalyst 23 can be maintained by energizing the heater 22 for heating the catalyst again by the signal of the temperature detecting unit 32 ( (Fig. 2).

As described above, by controlling the energization amount of the heater 22 for heating the catalyst by the signal from the temperature detection unit 32 that detects the temperature of the catalyst 23, the catalyst 23 can be used in an unnecessarily high temperature state. And the life of the catalyst can be dramatically improved.

Further, the mounting position of the temperature detection unit 32 is located upstream of the catalyst 23,
Although it is provided in the secondary combustion chamber 18, the temperature of the catalyst 23 may be directly detected by embedding a thermocouple in the catalyst 23, or a temperature detection unit 32 may be provided downstream of the catalyst 23 to detect the exhaust gas temperature. The same effect can be obtained by controlling the energization amount of the heater 22 for heating the catalyst.

Although the description so far has been made on the case where the thermocouple is used for the temperature detection unit 32, the same control can be performed by using an optical sensor or the like for the temperature detection unit 32.

Effects of the Invention As described above, in the present invention, the durability of the heater for heating the catalyst is improved, the catalyst is not used unnecessarily in a high temperature state, and the life of the catalyst can be dramatically improved. .

[Brief description of drawings]

FIG. 1 is a sectional view of a waste treatment device according to an embodiment of the present invention,
FIG. 2 is a time characteristic diagram of a signal of a temperature detecting part of the same device, and FIG.
The figure is a cross-sectional view of a conventional waste treatment device. 17 ... Primary combustion chamber, 18 ... Secondary combustion chamber, 21 ... Secondary air chamber, 22 ... Catalyst heating heater, 23 ... Catalyst, 24 ... Magnetron, 32 ... Temperature detection unit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshitaka Kawasaki 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) Reference JP 62-218709 (JP, A) JP 62-218710 (JP, A) JP-A-48-2879 (JP, A) JP-A-53-106668 (JP, A)

Claims (1)

[Claims] 1. A combustion chamber is divided into a primary combustion chamber and a secondary combustion chamber by a microwave attenuator, and a blowing means is provided for supplying combustion air to the primary combustion chamber and the secondary combustion chamber. A waste container is provided in the primary combustion chamber, the primary combustion chamber and the magnetron are connected by a waveguide, and a catalyst is provided downstream of the secondary combustion chamber located downstream of the primary combustion chamber. A means for detecting the temperature of the catalyst is provided, a secondary air chamber is provided on the outer periphery of the secondary combustion chamber, a heating means for heating the catalyst and the secondary combustion chamber is provided in the secondary air chamber, and the catalyst temperature is set. A waste treatment apparatus, wherein the heating amount of the heating means is controlled by a signal from the detection means.