JPH057605B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to garbage, wood chips, coal, waste plastics,
When waste materials such as waste rubber and tires are carbonized and burned to extract thermal energy, the amount of air for carbonization at the start of operation and at the end or stop is automatically controlled to reduce the explosive limit that is likely to be generated in the carbonization furnace. This was done with the aim of avoiding concentration ranges.

[Conventional technology] When starting combustion in a carbonization gasifier and adding fuel,
Or, at the end of operation or when the furnace is shut down, unburned gas stagnant in the furnace mixes with air and forms the explosion limit, which has often been experienced. In some cases, it may only cause a backfire, but it is extremely dangerous.

In a carbonization gasification furnace, the gas concentration depends on the amount of air supplied from the start of operation in a cold state until a predetermined gas output is obtained. This tendency is particularly noticeable when starting from a cold state, and the amount of air needs to be controlled according to the gas generation situation.

Generally, the control range of a temperature indicating controller (proportional control type) is 80% in the proportional band, and 1 to 100% in special cases.
There are some that are 1000%, but these have complicated structures, are expensive, and are not common. Among the temperature indicating controllers, many of the inexpensive and easily available general-purpose ones have a proportional band of 1 to 50%, for example, the full scale is 0 to 1600℃, and the pointer is 1600℃ beyond the set value of 1200℃.
℃, the air adjustment valve is fully closed, the set value is lowered, and when the temperature reaches 800℃, it is fully opened.The proportional band is (1600-800)/1600=0.5=50%, and as shown below. The temperature range controller is suitable for the carbonization gasification of wastes such as the aforementioned garbage, wood chips, coal, waste plastics, waste rubber, and tires.

[Problem that the invention seeks to solve]

However, with this temperature indicating controller having a proportional band, the air regulating valve cannot be fully closed even at low temperatures when the carbonization gasifier starts firing, and the opening of the air regulating valve cannot be adjusted below 800°C. This results in a large amount of excess air being introduced into the furnace.
There was a great danger of reaching the explosive limit, and countermeasures were desired. This dangerous situation is the same even when the carbonization furnace is finished operating or stopped.

Furthermore, with the currently widely used controllers with a proportional band of 50%, control outside the limits of the control range is compensated for by manual operation, which has been an obstacle to the complete automation of carbonization gasification and combustion equipment.

[Means to solve the problem]

In view of the above, the present invention provides air introduction at the beginning, end, or stop of carbonization gasification of waste.
During or after reaching the lower limit temperature of 800°C on the temperature indicating controller, or during the period when the lower limit temperature drops from 800°C to room temperature, the opening degree of the air adjustment valve due to excessive opening according to the temperature indicating controller is changed. The device automatically adjusts the valve opening to allow the flow of air that matches the temperature inside the furnace, thereby keeping the gas components inside the furnace outside the explosion limit. A thermometer to measure the temperature of the combustion gas is installed in the gas combustion furnace of the gasification combustion equipment, and a valve with an actuator is installed in the air supply pipe (or duct) to the carbonization gasification furnace, and automatic adjustment is also performed. In order to open and close the valve so as to keep the temperature of the combustion gas constant, the thermometer, the automatic controller, and the valve constitute a control loop, and when the carbonization gasification and combustion apparatus is started up and In order to prevent the valve from opening too much in the low-temperature transient state at the time of shutdown, the valve opening is adjusted to the normal operating state based on the signal from the combustion gas thermometer or another combustion gas thermometer. This is an automatic control method for a carbonization gasification/combustion apparatus configured to automatically set a narrow opening degree in the vicinity of 100 degrees.

[Effect]

According to the above configuration, the present invention can prevent the air regulating valve from opening too much due to the action of the temperature indicating controller in the low-temperature transient state at the time of startup, final stage, or shutdown of the carbonization gasifier. The indicating controller is shut off, and based on the signal from the thermometer that measures combustion gas or another combustion gas thermometer, the air adjustment valve opening is set to a narrow opening close to the opening under steady-state operation. For example, a voltage generator applies a constant voltage to a temperature indicating controller to open and close an air regulating valve with an actuator.

〔Example〕

The figure is an explanatory diagram of an embodiment of the present invention.

The carbonization gasification furnace 1 has an air supply pipe 5 having a blower 2 and an air regulating valve 4 with an actuator 3 below.
A combustible material inlet 6 is provided at the top, and a carbonization gas take-off pipe 7 opens on the side. A combustion furnace 8 is provided in communication with the pipe 7, and high-temperature combustion gas is disposed of through an outlet 9. The heat energy is introduced into a heat recovery device (not shown) such as a heat boiler, and the heat energy is effectively used.

The temperature control loop 10 includes a temperature indicator 1 equipped with thermocouple temperature sensors A and B provided at the outlet 9, a variable voltage generator 11, and a switching contact 12.
3. It is composed of a temperature indicating controller 14 and an air regulating valve 4 with the actuator 3, and its operation will be described below.

When starting the operation of the carbonization gasifier, first, the temperature indicator 13 and temperature indicator controller 14 are set to a set value corresponding to the desired combustion output, for example, 1200°C. Next, the variable voltage generator 11 is operated to apply an arbitrarily appropriate voltage output to the temperature indicating controller 14 so that the air adjustment valve opening becomes a narrow opening close to the opening in the steady operating state. The temperature indicating controller 14 transmits a pulse signal corresponding to the applied voltage value to the air regulating valve 4 with an actuator, and the degree of opening and closing of the valve 4 is determined.
In this way, the output of the variable voltage generator 11 is adjusted so that the valve opening degree is determined in advance.

Next, the ignition port 1 is placed in the combustible material 15 in the carbonization gasification furnace 1.
6, and the blower 2 starts operating. As mentioned above, the air regulating valve 4 is fixed at a set opening narrower than the normal opening due to the set voltage output of the variable voltage generator 11, the amount of air is limited, combustion carbonization proceeds slowly, and the generated carbonized gas The oxygen concentration inside is also low,
The amount is about 1.0 to 2.6%, which is outside the explosive limit and can be operated safely. Carbonization progresses in this manner, and the amount of gas generated increases. The carbonized gas reaches the combustion furnace 8, where it is ignited by an ignition burner, and with the supply of air, combustion becomes active and the temperature of the combustion gas rises.

This combustion gas temperature is the initially set temperature 1200℃
When the voltage generated by the temperature sensor A automatically operates and switches the switching contact 12 built in the temperature indicator 13, the variable voltage generator 11
The voltage output of the temperature sensor B is cut off, and the output of the temperature sensor B is automatically input to the temperature indicating controller 14. By this switching, the opening degree of the actuator-equipped air regulating valve 4 is adjusted based on the signal issued by the temperature indicating controller 14, the amount of introduced air is adjusted, and the generated gas temperature is kept constant.

Thereafter, as long as there is combustible material 15 in the furnace, the temperature is automatically controlled by the temperature indicating controller 14 and the actuator-equipped air regulating valve 4 according to the change in the voltage generated by the temperature sensor B.

As the combustion furnace 8 approaches the end of combustion, the gas outlet temperature of the combustion furnace 8 decreases, so the voltage generated by the temperature sensor A decreases, the switching contact 12 switches, and the air regulating valve 4 returns to the variable voltage due to the reverse operation from the start. It operates according to the generated amount 11, limits the opening degree of the air regulating valve 4, and reduces the amount of air.

The temperature indicator 13 and the temperature sensor A may be replaced by a temperature sensor with a contact point. Also, temperature sensors A and B may be separate as described above, but
It is also possible to use another circuit to branch the signal into one sensor. Various types of temperature sensors, controllers, etc. are commercially available, and depending on which one is used, signals, circuit configurations, etc. may differ from those of the above embodiments, but the gist of the present invention is is as described in the claims and is not limited to the above embodiments.

〔Effect of the invention〕

In the present invention, a thermometer for measuring the temperature of combustion gas is installed in the generated gas combustion furnace of a carbonization gasification combustion apparatus, and an air supply pipe (or duct) to the carbonization gasification furnace is installed.
A valve with an actuator is installed inside, and an automatic controller is further installed to open and close the valve so as to keep the combustion gas temperature constant. At the same time, the valve is controlled by the signal from the above or another combustion gas thermometer to prevent the valve from opening too much due to the action of the automatic controller in the low-temperature transient state when starting and stopping the carbonization gasification combustion equipment. The purpose of the present invention is to provide an automatic control method for a carbonization gasification combustion apparatus configured to automatically set the opening degree of the valve to a narrow opening degree close to the opening degree in the steady operation state based on the above-mentioned conditions. Even if it is outside the adjustment control range of the temperature indicating controller during startup or in the final low temperature transient state, the control range is forcibly suppressed by the voltage value output by the variable voltage generator, and the opening degree of the air adjustment valve is controlled. The opening can be restricted to a narrow degree, the amount of air supplied can be reduced, and the oxygen concentration in the generated carbonized gas can be low, reducing the chance of reaching the explosive limit concentration, further increasing safety.

Moreover, in the past, control of control parts outside the limits of the control range was performed manually, which was an obstacle to automation, but by adopting this control loop, automation is possible, and temperature control is also controlled by a variable voltage generator. The voltage applied to the controller can be set in advance to any value depending on the type of combustible material, so even if the combustible material is diverse, such as trash, wood chips, coal, waste plastics, waste rubber, tires, etc. Since variable voltage generators can be matched, they are highly versatile, and variable voltage generators are inexpensive and easily available, so they have great economic effects.

[Brief explanation of the drawing]

The figure is an explanatory diagram of an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Carbonization gasification furnace, 2... Air blower, 3... Drive actuator, 4... Air adjustment valve, 5... Air supply pipe, 6... Combustible material inlet, 7... Carbonization gas extraction pipe, 8... Combustion furnace, 9... Exit, 10...
Temperature control loop, 11... Variable voltage generator, 12
...Switching contact, 13...Temperature indicator, 14...Temperature indicator controller, 15...Combustible material, 16...Ignition port.

Claims (1)

[Claims] 1. A thermometer for measuring the temperature of combustion gas is installed in the generated gas combustion furnace of the carbonization gasification combustion equipment, and a valve with an actuator is installed in the air supply pipe (or duct) to the carbonization gasification furnace, and In order to open and close the valve to keep the temperature of the combustion gas constant by providing an automatic controller, the thermometer, the automatic controller, and the valve constitute a control loop,
In order to prevent the valve from opening too much due to the action of the automatic controller, the valve is adjusted based on the signal from the combustion gas thermometer or another combustion gas thermometer to prevent the valve from opening too much during low temperature transient conditions when starting and stopping the carbonization gasification combustion equipment. An automatic control method for a carbonization gasification combustion equipment configured to automatically set the opening of the engine to a narrow opening close to the opening of a steady operating state.