JPH11304127A - Pressure controller for heating medium of pyrolytic reactor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the air in the heat transfer tube of a pyrolytic reactor front leaking out even when, for example, the heat transfer tube is broken so that the inside of the rector may be maintained in a low-oxygen atmosphere. SOLUTION: A high-temperature air heater 1 is formed in such a structure that part of the heating medium of the heater 1 leaks out of a heating medium circulating line 3 and a first connecting duct 7 which is communicated with the atmosphere and has a first control valve 6 is provided on the suction side of a blower 4. In addition, a second connecting duct 9 which is communicated with the atmosphere and has a second control valve 8 is provided on the discharge side of the blower 4 and an air pressure sensor 10 which detects the air pressure is installed to an air pipe 2 near the heating medium inlet of the reactor 52 so that the air pressure of the heating medium flowing through the heat transfer tube of the rector 52 may be adjusted to the same pressure or lower than the atmospheric pressure in the reactor 52 by controlling the control valves 6 and 8 of the ducts 7 and 9 based on the pressure detecting signal of the sensor 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to industrial waste such as waste (general waste such as municipal waste from homes and offices, waste plastic, car shredder dust, waste office equipment, electronic equipment, cosmetics, etc.). The present invention relates to a pyrolysis reactor for thermally decomposing the waste prior to incineration of a substance containing combustibles, and more particularly to a heat medium pressure control device and a waste treatment device provided with the same.

[0002]

2. Description of the Related Art As one of treatment apparatuses for waste including general waste such as municipal solid waste and combustibles such as waste plastics, the waste is put into a thermal decomposition reactor and heated in a low oxygen atmosphere to heat the waste. Decomposes to generate a pyrolysis gas (dry distillation gas) and a pyrolysis residue mainly composed of non-volatile components. The pyrolysis gas and the pyrolysis residue are separated in a discharge device, and the pyrolysis residue is further purified. After cooling with a cooling device under an active atmosphere, it is supplied to a separation device and separated into a combustible component mainly composed of pyrolytic carbon and a non-combustible component such as metal, pottery, and gravel. Pulverized to a powder, and the pulverized combustible component and the above-mentioned pyrolysis gas are used as fuel (combustible material).
As a result, it is guided to a combustion melting furnace and burned at a temperature of about 1300 ° C., and the generated combustion ash is heated by the combustion heat to form molten slag. A known waste treatment apparatus is known (Japanese Patent Publication No. 6-56253). The high-temperature combustion exhaust gas (about 1200 ° C) generated in the combustion melting furnace is recovered thermal energy by a high-temperature air heater provided at the subsequent stage, and is further collected by a dust collector, and finally is cleaned with a clean exhaust gas. And is released into the atmosphere from the chimney.

Here, a high-temperature air heater and a thermal decomposition reactor are connected by an air pipe, and a heat medium circulation line is formed so that a heat medium can be circulated. Further, a blower is provided between the downstream side of the thermal decomposition reactor and the upstream side of the high-temperature air heater in the heat medium circulation line, and a downstream side of the high-temperature air heater in the heat medium circulation line. A starting furnace is provided between the furnace and the upstream side of the pyrolysis reactor. Then, the air heated to about 550 ° C. by the high-temperature air heater is sent as a heat medium to the pyrolysis reactor through the line,
The waste in the pyrolysis reactor is indirectly heated to about 300 ° C.
And leaves the pyrolysis reactor. This air is sent by the blower to the hot air heater where it is heated again and recirculated.

The high-temperature air heater has a structure in which a part of the heat medium is used as a purge gas and leaks out of the heat medium circulation line because of its improved corrosion resistance and the like. As a result, the amount of air circulating in the heat medium circulation line decreases, and it is necessary to replenish the air. The replenishment of the air is performed by sucking an amount corresponding to the leak amount of the air into the line from a ventilation duct provided to the line and open to the atmosphere.

[0005]

As described above, in the thermal cracking reactor, the waste moving in the thermal cracking reactor is indirectly heated by the heating medium air flowing in the heat transfer tube to generate the thermal cracking gas. And pyrolyzed residue.
If the heat transfer tube breaks, the air pressure inside the heat transfer tube is higher than the outside, so part of the heat medium air leaks into the vessel, making it difficult to maintain the inside of the vessel in a low oxygen atmosphere. There was a problem.

An object of the present invention is to prevent the air in the heat transfer tube from leaking to the outside even if the heat transfer tube of the pyrolysis reactor is pierced, thereby maintaining the inside of the pyrolysis reactor in a low oxygen atmosphere. It is an object of the present invention to provide a heat medium pressure control device for a pyrolysis reactor and a waste treatment device provided with the same. Another object of the present invention is to make it possible to detect a rupture in the heat transfer tube of the thermal decomposition reactor at an early stage.

[0007]

In order to achieve the above-mentioned object, the present invention is characterized in that a high-temperature air heater for recovering heat of combustion exhaust gas by air as a heat medium and a heat passing through a heat transfer tube. A pyrolysis reactor for indirectly heating and thermally decomposing waste with medium air, a heat medium circulating line for connecting the pyrolysis reactor and the high-temperature air heater with an air pipe to circulate a heat medium, A blower provided between a downstream side of the pyrolysis reactor of the medium circulation line and an upstream side of the high-temperature air heater, and a blower provided between the downstream side of the high-temperature air heater of the heating medium circulation line and the pyrolysis reaction A heating furnace provided between the heating medium and the upstream side of the heating device, wherein the high-temperature air heater is formed in a structure in which a part of the heating medium leaks out of the heating medium circulation line, and the suction of the blower is performed. Connects to the atmosphere on the side and has a first control valve A first communication duct is provided, a second communication duct having a second control valve connected to the atmosphere on the discharge side of the blower is provided, and an air pressure detecting air pressure is provided to an air pipe near a heat medium inlet of the pyrolysis reactor. A control valve for controlling the control valves of the first communication duct and the second communication duct based on a pressure detection signal of the air pressure sensor, and detects a pressure of a heat medium passing through a heat transfer tube of a thermal decomposition reactor by the thermal decomposition. The pressure is equal to or slightly lower than the atmospheric pressure in the reactor.

Accordingly, even if the heat transfer tube of the thermal decomposition reactor is punctured, the air pressure in the heat transfer tube is maintained at the same level as that of the outside or slightly lower than that of the outside. Therefore, the inside of the thermal decomposition reactor can be maintained in a low oxygen atmosphere. Here, the "slightly" in maintaining "slightly low pressure" means that when the pressure is low,
Conversely, intrusion of the external gas into the heat transfer tube occurs, but the intrusion implies that the overall balance inside and outside the heat transfer tube is so small as not to be destroyed.

According to a second aspect of the present invention, in the first aspect of the present invention, a CO concentration detecting means is provided near a heat medium outlet of the thermal decomposition reactor in the heat medium circulation line. . When a puncture occurs in the heat transfer tube, the pyrolysis gas (including CO), which is an external gas, slightly penetrates into the heat medium air inside the heat transfer tube, and the puncture is detected by detecting the CO with the CO concentration detecting means. What happened can be accurately grasped and responded at the initial stage.

The third aspect of the present invention is the first or second aspect.
In the described invention, a bypass line that bypasses the thermal decomposition reactor is provided in the thermal medium circulation line, and a first thermometer that detects air temperature is provided in an air pipe near the thermal medium inlet of the thermal decomposition reactor, A second thermometer for detecting an air temperature is provided in an air pipe near a heat medium outlet of the decomposition reactor,
A third thermometer for detecting air temperature is provided in an air pipe near a heat medium outlet of the high-temperature air heater, a third control valve is provided in the bypass line, and the third thermometer is provided near a heat medium outlet of the pyrolysis reactor. A fourth regulating valve is provided in the air pipe upstream of the junction with the bypass line, and controls the fuel flow rate of the starting heating furnace or the number of revolutions of the blower based on the detection signal of the first thermometer. The rotation number of the third control valve and the fourth control valve or the blower is controlled by a detection signal of a thermometer,
The number of rotations of the blower is controlled by a detection signal of a third thermometer, and the temperature of the air flowing through the heat transfer tube of the thermal decomposition reactor is maintained within a set range by these controls. Is what you do.

Normally, the inlet temperature of the heating medium air of the thermal decomposition reactor is set to about 550 ° C. and the outlet temperature is set to about 300 ° C. According to the present invention, the heating medium is controlled while controlling the pressure. The temperature can be maintained at the desired temperature.

[0012] The present invention provides a pyrolysis reactor for pyrolyzing waste to produce a pyrolysis gas and a pyrolysis residue, and a cooling device for cooling the pyrolysis residue in an inert atmosphere. A separation device for separating the cooled pyrolysis residue into a combustible component and a non-combustible component, and combusting the pyrolysis gas and the combustible component at a temperature at which ash is melted to discharge unburned components as molten slag. In a waste treatment apparatus provided with a combustion melting furnace discharged from the section and a high temperature air heater for exchanging heat of the high temperature gas generated in the combustion melting furnace with air for heat recovery, the thermal decomposition reactor is characterized in that: A heat medium pressure control device according to any one of claims 1 to 3 is provided.

Thus, even if the heat transfer tube of the thermal decomposition reactor should be punctured, it can be reliably detected at the initial stage and the operation can be stopped immediately.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a heat medium pressure control device for a thermal decomposition reactor according to the present invention will be described below with reference to FIG. In FIG. 1, a high-temperature air heater 1 recovers heat of a combustion exhaust gas by using air as a heat medium.
The thermal decomposition reactor 52 is for indirectly heating and thermally decomposing waste moving in the thermal decomposition reactor 52 by a heat medium air passing through a heat transfer tube (not shown). The thermal decomposition reactor 52 and the high-temperature air heater 1 are connected by an air pipe 2 to form a heat medium circulation line 3 through which the heat medium is circulated. Then, the downstream side of the thermal decomposition reactor 52 of the heat medium circulation line 3 and the high-temperature air heater 1
A blower 4 is provided between the heating medium circulation line 3 and the downstream side of the high-temperature air heater 1 and the thermal decomposition reactor 5.
The starting heating furnace 5 is provided between the heating furnace 5 and the upstream side of the heating furnace 5.
In this example, the line 3 is provided with a bypass line 12 that bypasses the pyrolysis reactor 52, and the bypass line 1
2. A heat exchanger 13 for cooling and a flow control valve 14 are provided.

The high-temperature air heater 1 is formed so that a part of the heat medium air leaks out of the heat medium circulation line 3. That is, the leak air 11 eliminates the possibility that an external corrosive gas component penetrates into the metal portion of the high-temperature air heater 1 and comes into contact with the metal portion.

A first communication duct 7 connected to the atmosphere on the suction side of the blower 4 and having a first control valve 6 for adjusting the flow rate is provided on the suction side of the blower 4. A second communication duct 9 having a valve 8 is provided. Further, an air pressure sensor 1 for detecting air pressure in an air pipe 2 near a heat medium inlet of the pyrolysis reactor 52.
0 is provided. Furthermore, a CO analyzer 16 is provided in the air pipe 2 near the heat medium outlet of the pyrolysis reactor 52.

Next, the operation of the above embodiment will be described.
First, when the starting heating furnace 5 is stopped, the first control valve 6 is controlled by the changeover switch 15 of the air pressure sensor 10, and the second control valve 8 is fully closed. The first control valve 6 is opened and closed by the air pressure sensor 10 so that the detected air pressure in the air pipe 2 is equal to or slightly lower than the atmospheric pressure in the pyrolysis reactor 52, and in this example, is controlled to be 0 mmAq. . Specifically, the leak air 11 of the high-temperature air heater 1
Is controlled so as to maintain the low pressure (0 mmAq) while replenishing the same amount of air, and this replenishment air is supplied through the first communication duct 7.
Causes a pressure loss, and the low pressure (0 mmA
Air supplementation can be performed while maintaining q).

When the starting heating furnace 5 is in operation, the second control valve 8 is controlled by the changeover switch 15 of the air pressure sensor 10, and the first control valve 6 is fully closed. This is because, when the starting heating furnace 5 is operated, exhaust gas is generated therefrom and the air pressure in the air pipe 2 of the line 3 increases. In this case, the same amount of air as the difference between the exhaust gas generated from the starting heating furnace 5 and the leak air 11 is discharged from the second communication duct 9 to the outside. That is, the air pressure sensor 1
0, the detected air pressure in the air pipe 2 is reduced
The opening and closing of the second control valve 8 is controlled so as to be equal to or slightly lower than the internal atmospheric pressure, and to be 0 mmAq in this example. At this time, the air can be discharged while maintaining the low pressure (0 mmAq) due to the pressure loss due to the presence of the second control valve 8. In the above description, the case where the control valves 6 and 8 are switched using the changeover switch 15 has been described. However, a sequence control in which the first control valve 6 and the second control valve 8 are not simultaneously opened may be constructed. In this case, the changeover switch 15 is unnecessary.

As described above, the control valves 6 and 8 of the first communication duct 7 and the second communication duct 9 are controlled based on the pressure detection signal of the air pressure sensor 10, and the thermal decomposition reactor 52
The operation is performed such that the air pressure of the heat medium passing through the heat transfer tube is equal to or slightly lower than the atmospheric pressure in the thermal decomposition reactor 52. Accordingly, even if the heat transfer tube of the thermal decomposition reactor 52 is punctured, the heat medium air does not leak from the inside of the heat transfer tube to the outside (inside the device), and the inside of the thermal decomposition reactor 52 is kept in a low oxygen atmosphere. The hole can be immediately detected by the CO analyzer.

FIG. 2 shows another embodiment of the present invention. This embodiment is controlled so as to satisfy the following conditions. Maintaining the temperature of the heating medium air at the inlet of the pyrolysis reactor at 550 ° C., maintaining the temperature of the heating medium air at the exit of the pyrolysis reactor at 300 ° C., and controlling the temperature of the heating medium air at the outlet of the high-temperature air heater Maintain 550 ° C or less, do not flow in the bypass line when operating the heating furnace for start-up, and keep the air pressure of the heat medium passing through the heat transfer tubes of the pyrolysis reactor equal to or slightly lower than the outside. To be. For this purpose, in this example, the heat medium circulation line 3 is provided with a first thermometer 20 for detecting the air temperature in the air pipe 2 near the heat medium inlet of the heat decomposition reactor 52.
A second thermometer 21 for detecting the air temperature is provided in the air pipe 2 near the heat medium outlet of the third thermometer 2, and a third thermometer 2 for detecting the air temperature in the air pipe 2 near the heat medium outlet of the high-temperature air heater 1 is provided.
2 are provided. Further, a third control valve 23 is provided in the bypass line 12, and a fourth control valve 24 is provided in the air pipe 2 near the heat medium outlet of the pyrolysis reactor 52 and upstream of the junction with the bypass line 12. Have been.

When the starting heating furnace 5 is stopped (including the operation of the minimum amount of kerosene), the rotation speed of the blower 4 is controlled via the switch 25 so that the first thermometer 20 maintains 550 ° C. In addition, the third control valve 23 of the bypass line 12 is controlled via the changeover switch 26 so that the second thermometer 21 maintains 300 ° C., and the flow rate of the air flowing therethrough is adjusted. Here, even when the third control valve 23 is fully opened, when the second thermometer 21 is at 300 ° C. or higher, the fourth control valve 24 is closed.

When the starting heating furnace 5 is operating (except for the operation with the minimum amount of kerosene), the starting heating furnace 5 is switched via the changeover switch 25 so that the first thermometer 20 maintains 550 ° C.
Is controlled via the switch 26 so that the second thermometer 21 maintains 300 ° C. When the rotation speed is reduced and the third thermometer is 550 ° C. or higher, the rotation speed of the blower 4 is adjusted via the switch 27 so that the temperature becomes 550 ° C. At this time, the temperature of the second thermometer becomes 300 ° C. or more. Therefore, the second thermometer 21 adjusts the third control valve 23 of the bypass line 12 to control the temperature to 300 ° C.

As described above, the fuel flow rate of the starting heating furnace 5 or the rotation speed of the blower 4 is controlled based on the detection signal of the first thermometer 20, and the third flow rate is detected by the detection signal of the second thermometer 21.
The number of rotations of the control valve 23 and the fourth control valve 24 or the blower 4 is controlled, and the number of rotations of the blower 4 is controlled by a detection signal of the third thermometer 22. It is formed so as to maintain the temperature of the flowing air within a set range. That is, in this example,
The inlet temperature of the heating medium air of the pyrolysis reactor 52 is about 550
The pressure control can be performed while maintaining the temperature at about 300C and the outlet temperature at about 300C.

Next, an embodiment of a waste treatment apparatus provided with a furnace temperature detecting device of the combustion melting furnace will be described with reference to FIG. In the waste treatment apparatus of the present embodiment, the waste 50a such as municipal waste is crushed into a size of 150 mm square or less by a crusher such as a biaxial shearing type.
It is loaded into the loading section 50 by a conveyor or the like. Input unit 5
The waste 50a put into the screw feeder 51
Is supplied to the inside of the thermal decomposition reactor 52. In this example, a horizontal rotary drum is used as the pyrolysis reactor 52,
The thermal decomposition chamber in the drum is operated by a sealing mechanism (not shown).
The inside is kept in a low oxygen atmosphere.

The waste 50a is thermally decomposed in the pyrolysis reactor 52, and its heat source is heated by the high-temperature air heater 1, which is a heat exchanger disposed downstream of the combustion melting furnace 53 described later. 8 g of heating air (heating medium) supplied through the heating medium circulation line 3 which is a heating air line. 8 g of the heated air makes the inside of the thermal decomposition reactor 52 300 to 60.
It is maintained at 0 ° C, usually around 450 ° C.

Furthermore, waste 50a heated by the heated air 8g is thermally decomposed to the pyrolysis gas G _1, becomes the pyrolysis residue 54 consisting mainly of non-volatile components, it is sent to the discharge device 55 Separated. The pyrolysis gas G ₁ separated by the discharge device 55 is supplied from above the discharge device 55 to the burner 56 of the combustion melting furnace 53 via the pyrolysis gas line L ₂ . Pyrolysis residue 54 discharged from discharge device 55
Is cooled to about 80 ° C. in an inert atmosphere by a cooling device 57 having a structure to be described later.

Thereafter, the cooled pyrolysis residue 54 is
For example, it is supplied to a known single or combined separation device 58 such as a magnetic separation type, an eddy current type, a centrifugal type or a wind separation type, where the fine combustible component 58d (including ash) and iron, rubble, etc. The non-combustible component 58c is separated into the non-combustible component 58c, and is collected and reused in the container 59.

Further, the combustible component 58d is mainly composed of pyrolytic carbon.
are milled below m becomes powder carbon, combustible component line L ₃ a via is supplied to the burner 56 of the burning melting furnace 53, pyrolysis gas G ₁ supplied from the pyrolysis gas line L ₂
It is burned in a high temperature range of about 1,300 ° C. with the supplied combustion air 61e from the air line L ₄ by the blower 61 and.

The ash generated by the above combustion becomes molten slag 53f due to the heat of combustion, adheres to the inner wall of the combustion melting furnace 53, further flows down the inner wall, falls from the bottom outlet 62 into a water tank 63, and solidifies by cooling. Is done. The combustion melting furnace 53 is generally referred to as a melting furnace, and burns a combustible component 58d such as carbon at a high temperature of about 1300 ° C., melts unburned components including ash, and forms a high temperature combustion with the molten slag 53f. It generates the exhaust gas G _2. The flue gas G ₂ is 2
~ 3m, gas flow of 1000 ~ 1100 ℃
Heat is recovered by the heat transfer tube of the high-temperature air heater 1 provided on the downstream side in the furnace.

Here, the high-temperature air heater 1 and the pyrolysis reactor 52 have the heat medium pressure control device shown in FIGS. This makes it possible to reliably maintain the inside of the thermal decomposition reactor 52 in a low-oxygen atmosphere even if the heat transfer tube has a hole or the like, and to detect the hole.

The flue gas G ₂ passing through the high-temperature air heater 1 is recovered by a waste heat boiler 64 via a flue gas line L ₅ , is subjected to dust removal by a dust collector 65, and is further purified by an exhaust gas purifier. After harmful components such as chlorine are removed at 66, the exhaust gas G ₃ is discharged into the atmosphere from the chimney 68 via the induction blower 67 as clean low-temperature exhaust gas G ₃ . The steam generated by the waste heat boiler 64 is used for power generation by a generator 69 having a steam turbine.

In the above, the present invention has been described in detail with reference to the illustrated embodiments. However, the present invention is not limited to only those embodiments, and various modifications can be made without departing from the spirit of the present invention. It goes without saying that a wide variety of modifications can be made.

[0033]

According to the present invention, even if the heat transfer tube of the thermal decomposition reactor breaks, the air in the heat transfer tube does not leak to the outside, so that the inside of the thermal decomposition reactor is kept in a low oxygen atmosphere. be able to.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an example of a heat medium pressure control device of a thermal decomposition reactor according to the present invention.

FIG. 2 is a configuration diagram showing another example of the heat medium pressure control device according to the present invention.

FIG. 3 is a schematic diagram of a waste disposal apparatus according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 High-temperature air heater 2 Air piping 3 Heat medium circulation line 4 Blower 5 Starting furnace 6 First control valve 7 First communication duct 8 Second control valve 9 Second communication duct 10 Air pressure sensor 16 CO analyzer 20 First Thermometer 21 Second thermometer 22 Third thermometer 23 Third control valve 24 Fourth control valve 52 Thermal decomposition reactor

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ken Miyaji 1 Yawata Kaigan-dori, Ichihara-shi, Chiba Mitsui Engineering & Shipbuilding Co., Ltd. Ship Company

Claims (4)

[Claims] A high-temperature air heater for recovering the heat of the combustion exhaust gas with air as a heat medium; a pyrolysis reactor for indirectly heating and thermally decomposing waste with heat medium air passing through a heat transfer tube; A heat medium circulating line connecting the pyrolysis reactor and the high-temperature air heater with an air pipe to circulate a heat medium, a downstream side of the heat decomposition reactor of the heat medium circulating line and an upstream of the high-temperature air heater; And a starter provided between the downstream side of the high-temperature air heater and the upstream side of the pyrolysis reactor in the heat medium circulation line, The high-temperature air heater is formed to have a structure in which a part of the heat medium leaks out of the heat medium circulation line, and a first communication duct having a first control valve connected to the atmosphere on the suction side of the blower is provided, When connected to the atmosphere on the discharge side of the blower, A second communication duct having a second control valve is provided, an air pressure sensor for detecting air pressure is provided in an air pipe near a heat medium inlet of the pyrolysis reactor, and the first pressure sensor is provided based on a pressure detection signal of the air pressure sensor. Controlling the control valves of the communication duct and the second communication duct so that the air pressure of the heat medium passing through the heat transfer tube of the pyrolysis reactor is slightly lower than the atmospheric pressure in the pyrolysis reactor. Heat medium pressure control device for cracking reactor. 2. The heat medium pressure control device for a thermal decomposition reactor according to claim 1, wherein a CO concentration detecting means is provided near a heat medium outlet of the thermal decomposition reactor in the heat medium circulation line. 3. The heat medium circulating line according to claim 1, wherein a bypass line for bypassing the thermal decomposition reactor is provided in the thermal medium circulating line, and air temperature is detected in an air pipe near an inlet of the thermal medium of the thermal decomposition reactor. 1 A thermometer is provided, and a second thermometer for detecting air temperature is provided in an air pipe near a heat medium outlet of the pyrolysis reactor, and an air temperature is detected in an air pipe near a heat medium outlet of the high-temperature air heater. A third thermometer is provided, a third control valve is provided in the bypass line, and a fourth control valve is provided in an air pipe near a heat medium outlet of the pyrolysis reactor and upstream of a junction with the bypass line. The fuel flow rate of the starting heating furnace or the rotation speed of the blower is controlled based on the detection signal of the first thermometer, and the third control valve and the fourth control valve or the third control valve are controlled by the detection signal of the second thermometer. Controls fan speed , The number of revolutions of the blower is controlled by a detection signal of a third thermometer, and the temperature of the air flowing through the heat transfer tube of the thermal decomposition reactor is maintained within a set range by these controls. The heat medium pressure control device of the thermal decomposition reactor. 4. A pyrolysis reactor that pyrolyzes waste to produce a pyrolysis gas and a pyrolysis residue, a cooling device that cools the pyrolysis residue in an inert atmosphere, A separation device for separating the decomposition residue into a combustible component and an incombustible component, and a combustion device in which the pyrolysis gas and the combustible component are burned at a temperature at which ash is melted, and the unburned component is discharged from a discharge portion as molten slag In a waste treatment apparatus provided with a melting furnace and a high-temperature air heater for exchanging heat of a high-temperature gas generated in the combustion-melting furnace with air for heat recovery, the thermal decomposition reactor is any one of claims 1 to 3. A waste treatment device comprising the heat medium pressure control device according to any one of claims 1 to 3.