JPH108064A5 - - Google Patents

Description

[0003]
[Problem to be solved by the invention]
Although pyrolysis gasification combustion technology is publicly known, its characteristics are not being fully utilized in the current situation where the need to prevent air pollution has increased. There are issues that need to be resolved, such as maintaining a uniformly high gas combustion temperature by utilizing the characteristic of being able to keep the amount of ventilation to a minimum, and preventing dust dispersion by utilizing the characteristic of being able to keep the amount of dust that floats to the surface in the primary combustion to a minimum, as well as issues that are common to all of these, such as easily and sufficiently non-pollutingly burning combustible waste in a relatively small combustion furnace, easily and economically utilizing heat by installing piping in nearby areas to make effective use of resources, and making it possible to convert power if necessary.

[0004]
[Means for solving the problem]
A number of vents are installed in parallel on the underside of the primary combustion chamber, each with its own control valve, and then connected to a blower via a blast pipe. The sediment layer installed in the primary combustion chamber is divided into layers, forming a layered structure from the raw material tank to the drying tank, pyrolysis tank, combustion tank, and storage tank in that order, and the raw materials are processed in succession. The exhaust port installed in the primary combustion chamber is connected to an inlet pipe installed inside the small diameter end of a conical secondary combustion tube to guide the generated gas. A long, narrow nozzle is installed on the outer diameter of the inlet pipe, and a long, narrow nozzle is installed on the outer periphery of the large diameter end of the combustion tube, which is then connected to a heat-resistant cylinder. Both nozzles are connected to a blower via a blast pipe, and outside air is discharged in a thin film in two stages to combust the generated gas.

[0005]
After passing through the heat-resistant cylinder, it passes through a cooler equipped with a cooling water pipe and is then connected to the outlet by a blower.

[0008]
[Operation] The primary combustion chamber is filled with raw materials to form a sediment layer, and oil paper is dropped into the sediment tank on the exhaust port side to ignite it, and then the blower is turned on to start operation. When the control valve located closest to the exhaust port among the many vents installed in parallel on the bottom surface of the primary combustion chamber is opened to an appropriate amount to ventilate, the sediment tank around the opening position forms a combustion tank with the supplied oxygen. In detail, it is connected to the unburned raw material tank to form a drying tank for contained moisture, then a pyrolysis tank is formed, and then a combustion tank is formed. Furthermore, a storage tank for slowly burning residual carbon is also formed, and the opening of the control valves installed in parallel is adjusted to match the required ventilation volume for each tank. When controlling, the combustion tank can reach up to about 1,000°C, while the drying tank is below 100°C and the pyrolysis tank generally finishes at below 500°C. The heat required for drying and pyrolysis is sufficient from the heat transfer from the combustion tank, so no oxygen supply is required. The gas generated from these chambers is mixed with the gas generated in each tank, so when the openings of the parallel vents are aligned with the position of the combustion tank and controlled with a control valve so that the total temperature is a relatively low 500°C or above, the hourly air flow rate into the primary combustion chamber can be kept to a minimum of around 0.2 to 0.3, expressed in terms of the air ratio for combustion. Therefore, the speed of the gas flow passing through each tank is very small, making it difficult for dust to float up.

[0009]
The gas generated in the primary combustion chamber passes through the exhaust port and enters the inlet pipe installed inside the small diameter side of the secondary combustion tube. The outside air is discharged at high speed in a thin film form by a blower from a long, thin nozzle installed on the outer periphery of the inlet pipe, so the generated gas is sucked in by the ejector effect. Since the generated gas is above the ignition temperature, it is mixed with the outside air and undergoes secondary combustion. However, if the amount of outside air is too large, it will be cooled by the outside air and will not be able to ignite. However, the thin film discharged from the nozzle mixes the gas sequentially inside the secondary combustion tube, and the gas is mixed like a candle flame. When gas is burned and the amount of outside air is stopped at an appropriate level, the temperature rises through reliable ignition and combustion, increasing the gas volume as it moves toward the larger diameter side, and when a sufficient amount of outside air is supplied again in a thin film from the long, slender nozzle to complete the gas combustion inside the heat-resistant cylinder, complete combustion is possible even with a small combustion air ratio of around 1.3 to 1.5, including the primary combustion chamber, so that because the amount of outside air supplied is small compared to the amount of heat generated, a uniform high temperature of 1,000°C or higher can be maintained, making it possible to address exhaust gas pollution.

[0010]
After complete combustion in the heat-resistant cylinder, the high-temperature combustion gas flows into a cooler where it is gradually cooled through heat exchange in a cooling water pipe. The gas is then sucked in by a blower, creating only a slight negative pressure inside the primary combustion chamber. The gas then passes through another cooler under the pressure of the blower and is discharged from the exhaust port. The hot water obtained in the cooling water pipe can be used for heat recovery in nearby areas, or it can be converted into pressurized steam to generate electricity in a steam engine.

[0014]
An embodiment will be described with reference to the drawings. In Figure 1, a primary combustion chamber (1) is divided by a partition wall (1a) and is provided with an exhaust port (1b) and a sediment layer (1c). A number of vents (2a), (2'a), and (2"a) are installed in parallel on the bottom surface (1d) of the chamber (1). Each is connected to a vent pipe (2) via an on-off valve (2c), (2'c), and (2"c) to a blower (2b). The on-off valve (2c) is connected to a controller (2d), and the blower (2b) is connected to a temperature sensor (2e) in the exhaust port (1b). The sediment layer (1c) above the open vents (2'a) and (2"a) forms a combustion tank (D). These are connected in this order to form a pyrolysis tank (C), a drying tank (B), and a raw material tank (A), and on the opposite side is a storage tank (E).

[0015]
The blower (2b') is connected to a nozzle (4a) via a ventilation pipe (4) and has a long, narrow opening on the outer periphery of the inlet pipe (3a). The nozzle (4a) discharges outside air in a thin film, and the ejector effect draws the generated gas from the primary combustion chamber (1) into the pipe (3a). The discharged outside air flows into the secondary combustion tube (3) and burns some of the unburned generated gas, raising its temperature. The ventilation pipe (4) passes through a pipe line (4b) that forms the outer periphery of the tube (3), and is connected to a nozzle (4c) that has a long, narrow opening. The outside air is again discharged in a thin film into a heat-resistant cylinder (3b) connected to the end of the tube (3), and the unburned gas is sufficiently gas-combusted within the cylinder (3b) for complete combustion.

[0016]
The heat-resistant cylinder (3b) is connected to the coolers (5) (6) having cooling water pipes (5a) (6a) inside via a gas pipe (6d). The cooling gas is sucked from the middle cylinder (6e) by a blower (8) and discharged to the cooler (7) via a pipe (8a). The gas then passes through the middle cylinder (7d) and the filled tank (11) covered with a roof (11a) and is discharged from the exhaust port (11b). Meanwhile, the cooling water passes through pipes (7b), (7c), (6b), (6c), (5b), (5c) as shown by the arrows, and is heat-exchanged with the combustion gas through the cooling water pipes (5a), (6a), (7a) in order to become pressurized steam, which drives the steam engine (12). After solidification, the water is sucked by a pump (12a). The condensed water is forced between the pipes (7c) and (6b) to join the cooling water, while part of the dust may fall and accumulate in the chamber (6f) below the cooler (6). The condensed water (7e) that falls and accumulates below the cooler (7) is measured with a water level gauge (9b) and divided into two routes: one route is sent from the discharge pipe (9) to the pump (9a), where it is injected from the alkaline agent tank (9b) and then sent from the port (9c) to the pipe (8a) to neutralize the exhaust gas, and the other route is sent from the port (9f) by adjusting the opening of the valve (9e) to the water tank (10) to evaporate using the residual heat of the cooler (6). A roof (11a) is installed on the water tank (10).

[0023]
After the raw materials are charged into the primary combustion chamber and ignited, the control valves at the required positions in the parallel-installed vents are opened to an appropriate amount to form a layer of accumulated material in the order of the raw material tank, drying tank, pyrolysis tank, combustion tank, and storage tank. This controls the amount of generated gas to be generated at the appropriate temperature with only a minimal amount of required ventilation, which has the advantage of reducing the construction costs of pyrolysis gasification and allowing pyrolysis gas to be generated with high precision in the primary combustion furnace.

[0025]
Since the amount of air passed into the primary combustion chamber is extremely small, the flow rate of the permeating gas in the deposition layer is very low, making it difficult for dust to float up. Therefore, there is an advantage that the amount of dust dispersed into the exhaust gas is extremely small to begin with, even without installing a dust collector.

[Brief explanation of the drawings]
FIG. 1 is a longitudinal sectional view of an embodiment of a gasification treatment apparatus for combustible waste.
[Explanation of symbols]
1 Primary combustion chamber 1b Exhaust port 1c Sediment layer 2 Vent pipe 2a, 2'a, 2"a Vent port 2b, 2b' Blower 2c, 2'c, 2"c Control valve 2d Control meter 3 Secondary combustion tube 3a Inlet pipe 3b Heat-resistant cylinder 4 Blower pipe 4a, 4c Nozzle 4b Blower pipe 5, 6, 7 Cooler 5a, 6a, 7a Cooling water pipe 8 Blower 11b Exhaust port 12 Steam engine A Raw material tank B Drying tank C Pyrolysis tank D Combustion tank E Storage tank

Claims (1)

A number of vents (2a), (2'a), and (2"a) are installed in parallel on the underside of the primary combustion chamber (1), and control valves (2c), (2'c), and (2"c) are connected to each of the vents, which are then connected to a blower (2b) via a blower pipe (2). This allows the deposition layer (1c) provided in the chamber (1) to be formed in layers in the order of the raw material tank (A), drying tank (B), pyrolysis tank (C), combustion tank (D), and storage tank (E), and the deposition layer (1c) provided in the chamber (1) is then formed in layers in the order of the raw material tank (A), drying tank (B), pyrolysis tank (C), combustion tank (D), and storage tank (E). The exhaust port (1b) placed in the exhaust pipe (1b) is connected to an inlet pipe (3a) installed inside the small diameter end of a conical secondary combustion tube (3), a nozzle (4a) with an elongated opening is provided on the outer periphery of the tube (3a), a nozzle (4c) with an elongated opening is provided on the outer periphery of the large diameter end of the tube (3) and is connected to a heat-resistant cylinder (3c), and a blower (2b') is connected from the air supply tube (4) to the nozzle (4a) and nozzle (4c).