JPH0650171B2 - 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 A conventional waste treatment device includes a mechanical treatment device called a disposer and a combustion type treatment device called an incinerator.
There was a formula. 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 that decomposes and burns the waste by using a magnetron or a heater has been proposed. This device will be described with reference to FIG.

In FIG. 2, the combustion chamber is divided into a primary combustion chamber 2 and a secondary combustion chamber 3 by a microwave attenuator 1, a waste storage unit 4 is installed inside the primary combustion chamber 2, and a waste 5 is disposed. set. The supply of combustion air and the energization of the catalyst heating heater 7 provided in the secondary air chamber 6 are started to heat the catalyst 8. Catalyst 8
When the temperature becomes higher than the activation temperature, the magnetron 9 starts to be energized.

2450MHz microwave is transmitted from the magnetron 9,
Irradiation into the primary combustion chamber 2 through the waveguide 10. For this reason, all microwaves are absorbed by the waste 5 and the waste 5
The water in the waste material evaporates, and the waste material 5 dries rapidly. Waste 5
The microwaves begin to heat the waste 5 once it has completely dried. When the waste 5 reaches a high temperature to some extent, carbonization of the waste 5 starts while generating a flammable gas from the waste 5. This combustible gas is mixed with the primary air supplied from the primary air port 11 and supplied to the secondary combustion chamber 3. The combustible air-fuel mixture sent to the secondary combustion chamber 3 is ignited by an igniter 12 provided in the secondary combustion chamber 3 and mixed with secondary air supplied from a secondary air port 13 to be secondary. To burn. The combustion gas is purified by the catalyst 8 and then discharged from the exhaust stack 13.

After that, the waste 5 receives microwaves according to the signal from the temperature detection unit 14, promotes carbonization while generating combustible gas, and the waste 5 is completely carbonized to generate combustible gas. Flame combustion continues in the secondary combustion chamber 3 until it disappears. When the waste 5 is completely carbonized, the flame in the secondary combustion chamber 3 is extinguished, solid combustion (industrial combustion) is started in the primary combustion chamber 2, and ashing is reached. In this way, the waste is treated.

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

The heating means provided in the combustion chamber dry the waste,
Combustible gas is generated by burning combustible gas. This combustible gas contains a large amount of solid content (smoke) therein, and it is difficult to make the mixing of the combustion air and the combustible gas good, and it is a gas that is extremely difficult to burn. For this reason, it is necessary to increase the amount of combustion air supplied for combustion as compared with a normal city gas or kerosene combustor, and a catalyst must be used for purifying exhaust gas. Considering the life of the catalyst, it is necessary to ignite the combustible gas generated from the waste as soon as possible in order to prolong the flame combustion time as long as possible. Therefore, it is necessary to maintain the temperature of the ignition heater at a high temperature to improve the ignitability.

However, when the temperature of the ignition heater is maintained at a high temperature, the radiant heat from the ignition heater affects the temperature detection unit provided in the secondary combustion chamber, and the combustion state can be accurately determined from the output of the temperature detection unit. Becomes difficult. If the amount of radiant heat of the ignition heater is constant, the output of the magnetron may be controlled by the output from the temperature detection unit in consideration of the effect of the radiant heat of the ignition heater. However, in reality, when the combustible gas generated from the waste material ignites, the temperature of the ignition heater rises due to the combustion heat. When the amount of combustion is large, the flame is formed in the upper part of the combustion chamber, so the influence of the flame is difficult to affect the heater for ignition, but when the amount of combustion is small, the flame is formed in the lower part of the combustion chamber. It is greatly affected by the heat of combustion of the flame. As a result, when the amount of combustion is small, the temperature of the ignition heater becomes high, and the radiant heat of the ignition heater causes the temperature detector to detect a temperature higher than the actual temperature. For this reason, even though the combustion amount is small, the temperature detection unit determines that the combustion amount is larger than the actual amount and does not increase the output of the magnetron significantly, so the amount of combustible gas generated is insufficient, Prone to poor combustion. Therefore, if the ignition heater is heated to a high temperature to improve the ignitability, there is a problem that the combustion amount cannot be accurately determined by the temperature detection unit.

The present invention provides a waste treatment device based on the above-mentioned conventional technology, which has a simple structure, eliminates the influence of radiant heat of an ignition heater, and can accurately control the amount of combustion by the output of a temperature detection unit. Is.

MEANS FOR SOLVING THE PROBLEMS The present invention constitutes a combustion chamber that is formed by dividing a primary combustion chamber that stores waste and a secondary combustion chamber that is located downstream thereof with a microwave attenuator. The chamber and the magnetron are connected by a waveguide, and there is an air blower for separately supplying combustion air to each combustion chamber as primary air and secondary air. Temperature detector is provided in the secondary combustion chamber to detect temperature. A magnetron control unit for controlling the output of the magnetron according to the output of the unit is provided, and an ignition heater is provided near the microwave attenuation unit in the secondary combustion chamber, and a current detection unit for detecting the current value of the ignition heater, A voltage control unit that changes the supply voltage of the ignition heater according to the current value of the current detection unit is provided.

Action The action of this technical means is as follows.

When the waste is irradiated with microwaves, the moisture contained in the waste evaporates and then a combustible gas is generated from the waste. The flammable gas is ignited by an ignition heater to form a flame in the secondary combustion chamber. The combustion heat at this time is detected by a temperature detection unit provided in the secondary combustion chamber, and the output of the magnetron is controlled to make the amount of combustion constant. The temperature detection unit receives radiant heat from the ignition heater, and it is difficult to accurately determine the combustion state from the output of the temperature detection unit.

Therefore, the current value of the ignition heater is detected, and the resistance value of the ignition heater is calculated from the current value and the voltage supplied to the ignition heater. Generally, the resistance value of a substance increases as the temperature rises. Therefore, if the temperature characteristic of the resistance value of the ignition heater is used, the temperature of the ignition heater at that time can be calculated from the resistance value. Therefore, the temperature of the ignition heater can be kept constant by controlling the voltage supplied to the ignition heater. Therefore, if the radiant heat amount of the ignition heater is taken into consideration, the combustion amount can be accurately controlled by the output value of the temperature detection unit.

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 16 and a secondary combustion chamber 17 by a microwave attenuator 15, a waste storage 18 is installed inside the primary combustion chamber 16, and a waste 19 is disposed. set. The catalyst 22 is heated by starting the supply of the combustion air and the energization of the catalyst heating heater 21 provided in the secondary air chamber 20. Catalyst 22
When the temperature rises to a temperature higher than the activation temperature, the magnetron 23 starts to be energized.

2450MHz microwave is transmitted from magnetron 23,
It is irradiated through the waveguide 24 into the primary combustion chamber 16. In the primary combustion chamber 16, the electric field distribution in the primary combustion chamber 16 is adjusted so that the electric field is concentrated on the waste 19 placed in the waste container 18. For this reason, all the microwaves are absorbed by the waste material 19, the water content of the waste material 19 evaporates, and the waste material 19 dries rapidly.

At this time, the permittivity of water contained in the waste 19 is much larger than the permittivity of the components contained in the other waste 19, so that it is completely absorbed by the water contained in the waste 19. Therefore, the microwaves begin to heat the waste 19 after the waste 19 is completely dry.

When the waste 19 becomes high in temperature to some extent, carbonization of the waste 19 starts while generating a flammable gas from the waste 19. This combustible gas is mixed with the primary air supplied from the primary air port 25 and supplied to the secondary combustion chamber 17. The combustible air-fuel mixture sent to the secondary combustion chamber 17 is ignited by the ignition heater 26 provided in the vicinity of the microwave attenuating portion 15 in the secondary combustion chamber 17, and
Secondary combustion is performed by mixing with secondary air supplied from the secondary air port 27. A microwave attenuator 15 such as punching metal is provided at the boundary between the primary combustion chamber 16 and the secondary combustion chamber 17 to prevent microwaves from entering the secondary combustion chamber 17. Therefore, the ignition heater 26 can ignite the combustible air-fuel mixture without being affected by receiving the microwave and causing arcing. The combustion gas is purified by the catalyst 22 and then discharged from the exhaust pipe 28.

After that, the waste 19 receives microwaves from the magnetron 23, promotes carbonization while generating combustible gas, and secondary combustion is performed until the waste 19 is completely carbonized and no combustible gas is generated. Flame combustion continues in chamber 17.

The specific operation relationship of the present invention will be described below. In the present invention, the temperature detecting section 29 is provided in the secondary combustion chamber 18 so that the temperature of the secondary combustion chamber 17 can be detected. Then, the signal of the temperature detection unit 29 is sent to the magnetron control unit 30, and the output of the magnetron is controlled so that the temperature of the temperature detection unit 29 becomes constant, so that the combustion amount is made constant.

On the other hand, when the temperature of the ignition heater 26 is maintained at a high temperature, the radiant heat from the ignition heater 26 affects the temperature detection unit 29 provided in the secondary combustion chamber 17, and the combustion state is accurately determined from the output of the temperature detection unit 29. Judgment becomes difficult. Ignition heater 26
If the amount of radiant heat of the
You just have to control the output of 23.

In general, the amount of radiant heat from a high-temperature object is proportional to the fourth power of the surface temperature of the object. Therefore, if the surface temperature of the ignition heater 26 is constant, the amount of radiant heat from the ignition heater 26 can be constant.

However, in reality, when the flammable gas generated from the waste 19 ignites, the temperature of the ignition heater rises due to the combustion heat. When the combustion amount is large, the flame is formed in the upper part of the secondary combustion chamber 17, so the influence of the flame is hard to exert on the ignition heater 26, but when the combustion amount is small, the flame is formed in the lower part of the secondary combustion chamber 17. Because it is formed, it is considerably affected by the heat of combustion of the flame. As a result, when the amount of combustion is small, the temperature of the ignition heater 26 becomes high, and the radiant heat of the ignition heater 26 causes the temperature detector 29 to detect a temperature higher than the actual temperature. For this reason, even though the combustion amount is small, the temperature detection unit 29 determines that the combustion amount is larger than the actual amount and does not increase the output of the magnetron 23 significantly. It is easy to cause poor combustion.

Therefore, in the present invention, the ignition heater 26 is connected to a current detection unit 31 capable of detecting the current value thereof, and the current detection unit 31 detects the current value of the ignition heater 26 and transmits a signal to the voltage control unit 32. The voltage control unit 32 calculates the resistance value of the ignition heater 26 from the signal sent from the current detection unit 31 and the voltage value supplied to the ignition heater 26 at that time. Then, the temperature of the ignition heater 26 is calculated from the temperature characteristic of the resistance value of the ignition heater 26, and the voltage value supplied to the ignition heater 26 is controlled so that the temperature of the ignition heater 26 becomes constant. Here, as for the supply voltage value, the effective voltage value may be reduced, the conduction angle control,
It suffices to control and vary the energization time such as zero-cross control and pulse control.

For this reason, the temperature of the ignition heater 26 is constantly constant regardless of the flame position formed in the secondary combustion chamber 17, so that the amount of radiant heat from the ignition heater 26 to the temperature detecting unit 29 is constant, and the temperature detection The output of the section 29 enables accurate control of the combustion amount.

As described above, in the present invention, the current detection unit that detects the current value of the ignition heater and the voltage control unit that changes the supply voltage of the ignition heater according to the current value of the current detection unit are provided, and the surface of the ignition heater is provided. By controlling the voltage value supplied to the ignition heater to keep the temperature constant, the influence of the radiant heat of the ignition heater can be eliminated, and the combustion amount can be accurately controlled by the output of the temperature detection unit.

[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 cross-sectional view of a conventional waste treatment device. 16 ... Primary combustion chamber, 17 ... Secondary combustion chamber, 23 ... Magnetron, 29 ... Temperature detection unit, 31 ... Current detection unit, 32 ... Voltage control unit.

Claims (1)

[Claims] 1. A combustion chamber formed by dividing a primary combustion chamber for storing waste and a secondary combustion chamber located downstream thereof by a microwave attenuator, wherein the primary combustion chamber and the magnetron are connected to each other. The temperature detection unit is provided with a blower unit that is connected by a waveguide and supplies combustion air to each of the combustion chambers as primary air and secondary air separately, and a temperature detection unit is provided in the secondary combustion chamber. A magnetron control section for controlling the output of the magnetron according to the output of the magnetron, and an ignition heater near the microwave attenuating section in the secondary combustion chamber for detecting a current value of the ignition heater. And a voltage control unit for changing the supply voltage of the ignition heater according to the current value of the current detection unit.