JP4384009B2 - Slide gate valve, double damper equipped with this slide gate valve, and pyrolysis gasifier equipped with this double damper - Google Patents

Description

  The present invention relates to a slide gate valve, a double damper provided with the slide gate valve, and a pyrolysis gasifier including the double damper, and more particularly, in a communication path having a pressure difference, in a high pressure side in a closed state. The sliding gate valve that prevents the flow of gas from the low pressure side to the low pressure side and can maintain its effect reliably and for a long time, the double damper equipped with this slide gate valve, and the thermal decomposition equipped with this double damper The present invention relates to a gasifier.

  Conventionally, in order to prevent gas flow from the high pressure side to the low pressure side in a communication path having a pressure difference, various slide gate valves that open and close the communication path have been used. For example, in order to prevent the flow of gas when an object to be charged is introduced into a hopper or the like, a double damper in which two slide gate valves are vertically installed at a predetermined interval in a communication path above the hopper is used. .

  This double damper prevents the flow of gas when the valve is opened by alternately opening and closing the upper and lower slide gate valves when the object to be charged is charged. On the other hand, in order to prevent the flow of gas when the slide gate valve is closed, the sliding valve body of the slide gate valve and the valve seat with which the valve body abuts are in close contact with each other to eliminate or reduce the gap. It is common to do.

  For example, a structure has been proposed in which a valve seat is pressed with an elastic body to be brought into close contact with the valve body to eliminate a gap (see Patent Document 1). In this proposal, in order to prevent the occurrence of gaps due to foreign matter biting into the valve seat, a fin-like dust cutter that slides on the upper surface of the valve body is provided, and a mechanism for removing foreign matter when the valve body slides is provided. Yes.

  In addition, a tube-shaped packing is provided between the sliding valve element and the lower end surface of the communication path, and when the valve is closed, air is pressed into the packing and expanded to close the gap between the valve element and the lower end surface of the communication path. A structure has been proposed (see Patent Document 2).

However, these proposals have a problem that it is impossible to prevent the occurrence of gaps due to sliding of the valve body, wear of the contact portion, deterioration with time, and the like. Further, even if the dust cutter or the like is used to prevent the foreign matter from being caught, there is a problem that a gap is generated because the foreign matter cannot be sufficiently prevented from being caught due to the size of the foreign matter or the like.
JP-A 49-106018 Japanese Utility Model Publication No.59-106400

  The purpose of the present invention is to prevent the flow of gas from the high pressure side to the low pressure side in the closed state in the communication path having a pressure difference, and to ensure that the effect can be maintained reliably over a long period of time, An object of the present invention is to provide a double damper equipped with the slide gate valve and a pyrolysis gasifier equipped with the double damper.

  In order to achieve the above object, the slide gate valve of the present invention is a slide gate valve for opening and closing a communication passage having a pressure difference, and disposing two slidable valve bodies for opening and closing the communication passage, A pressure sensor for detecting a pressure difference between a pressure between the valve bodies and a pressure on a higher pressure side than the valve bodies in the communication path; and a pressure lower than the valve bodies in the communication path between the valve bodies. And a control device for reducing the pressure difference by controlling the gas supply amount from the supply pump based on the pressure difference detected by the pressure sensor in the closed state of both valve bodies. It is characterized by comprising.

  The double damper of the present invention is a double damper in which two slide gate valves are connected to a communication passage having a pressure difference at a predetermined interval, and at least one of the slide gate valves is opened and closed. Two slidable valve bodies that are spaced apart from each other, a pressure sensor that detects a pressure difference between the pressure between the two valve bodies and a pressure on the higher pressure side of the two valve bodies in the communication path; A supply pump for supplying a gas at a lower pressure than the two valve bodies in the communication path between the valve bodies, and a pressure difference detected by the pressure sensor in a closed state of the both valve bodies from the supply pump. The slide gate valve includes a control device that controls the gas supply amount to reduce the pressure difference.

  Further, the pyrolysis gasification apparatus of the present invention includes a gasification furnace that gasifies by thermally decomposing waste in a low-oxygen atmosphere, and a waste that is thrown into the gasification furnace through a communication path having a pressure difference. In the pyrolysis gasification apparatus comprising a waste input system and a residue discharge system for discharging the combustion residue of waste input from the gasification furnace through a communication passage having a pressure difference, the waste input system and the residue discharge At least one of the systems is provided with a double damper that connects two slide gate valves at a predetermined interval, and at least one of the slide gate valves is separated from two slidable valve bodies that open and close the communication passage. And a pressure sensor for detecting a pressure difference between the pressure between the two valve bodies and a pressure on the higher pressure side of the communication passages than the two valve bodies, and both the communication passages between the two valve bodies. Supply gas on the low pressure side of the valve body A slide gate comprising: a supply pump; and a control device for reducing the pressure difference by controlling a gas supply amount from the supply pump based on a pressure difference detected by the pressure sensor when both the valve bodies are closed. It is characterized by being a valve.

  According to the slide gate valve of the present invention, a slide gate valve that opens and closes a communication passage having a pressure difference, the two slidable valve bodies that open and close the communication passage are arranged apart from each other, A pressure sensor for detecting a pressure difference between the pressure and the pressure on the higher pressure side than both valve bodies of the communication path, a supply pump for supplying a gas on the lower pressure side than both valve elements of the communication path between both valve bodies, And a control device for reducing the pressure difference by controlling the gas supply amount from the supply pump based on the pressure difference detected by the pressure sensor in the closed state of the valve body. It is possible to reduce the gas flowing between the valve bodies from the higher pressure side than the both valve bodies. On the other hand, although the gas flowing into the low pressure side from both valve bodies increases from both valve bodies, most of the inflowing gas is gas supplied from the low pressure side than both valve bodies.

  Therefore, the amount of gas that substantially passes through both valve bodies and flows from the high-pressure side to the low-pressure side is a gas that flows from the high-pressure side to the both valve bodies rather than both valve bodies. It is possible to prevent gas from flowing from the high pressure side to the low pressure side of the passage.

  Furthermore, even if the clearance in the closed state becomes large due to sliding caused by repeated opening and closing of the valve body, wear of the abutting portion, or foreign object biting, the above effect is affected by the increase in the clearance. Since this does not occur, this effect can be maintained reliably and over a long period of time.

  According to the double damper of the present invention, in a double damper in which two slide gate valves are connected to a communication passage having a pressure difference at a predetermined interval, at least one of the slide gate valves is opened and closed. Two slidable valve bodies are arranged apart from each other, a pressure sensor that detects the pressure difference between the pressure between the two valve bodies and the pressure on the higher pressure side of both valve bodies, and the communication path between the two valve bodies The supply pump that supplies the gas on the low pressure side of both valve bodies, and the gas supply amount from the supply pump is controlled based on the pressure difference detected by the pressure sensor when both valve bodies are closed, and this pressure difference is Since the slide gate valve is provided with the control device for reducing the size, the effect of the slide gate valve can be obtained. That is, in the closed state of the slide gate valve, it is possible to prevent the gas from flowing from the high pressure side to the low pressure side of the communication path, and to maintain this effect reliably and over a long period of time.

  In addition, the effect of the double damper, that is, the flow of gas from the high pressure side to the low pressure side of the communication passage when the slide gate valve is opened can be prevented, and when the slide gate valve is opened and closed In any case, excellent barrier properties against gas flow can be exhibited.

  According to the pyrolysis gasification apparatus of the present invention, a gasification furnace that thermally decomposes waste in a low-oxygen atmosphere and gasifies it, and a waste that throws the waste into the gasification furnace through a communication path having a pressure difference In a pyrolysis gasifier having a waste input system and a residue discharge system that discharges combustion residues of waste input from the gasification furnace through a communication passage having a pressure difference, the waste input system and the residue discharge system At least one is provided with a double damper that connects two slide gate valves at a predetermined interval, and at least one of the slide gate valves is arranged with two slidable valve elements that open and close the communication passage being spaced apart from each other. , A pressure sensor that detects the pressure difference between the pressure between both valve bodies and the pressure on the higher pressure side than both valve bodies in the communication path, and the gas on the lower pressure side than both valve bodies in the communication path is supplied between both valve bodies Pressure in the closed state of the supply pump and both valve bodies Since the slide gate valve is provided with a control device that controls the gas supply amount from the supply pump based on the pressure difference detected by the sensor to reduce this pressure difference, the slide gate valve and the double damper have An effect can be obtained.

  That is, in the closed state of the slide gate valve, it is possible to prevent the gas flow from the high pressure side to the low pressure side of the communication path of the waste input system and the residue discharge system, and this effect is ensured for a long time. Can be maintained.

  In addition, gas flow from the high-pressure side to the low-pressure side of the communication path of the waste input system and residue discharge system when the slide gate valve is opened can be prevented, and when the slide gate valve is opened and closed In any case, excellent barrier properties against gas flow can be exhibited.

  As a result, when the inside of the gasifier has a negative pressure, it is possible to prevent the quality of the generated gas from being deteriorated due to the inflow of outside air into the gasifier. Moreover, when the inside of a gasification furnace is a positive pressure, it becomes possible to prevent outflow of the product gas from the gasification furnace to the atmosphere.

  Hereinafter, a slide gate valve, a double damper, and a pyrolysis gasifier of the present invention will be described based on the embodiments shown in the drawings. FIG. 1 illustrates an overall outline of the slide gate valve 1. The slide gate valve 1 is attached to the communication path 9 having a pressure difference, and a high-pressure side communication path 9a (upper side in the figure) and a low-pressure side communication path 9b (lower side in the figure) are formed.

  The slide gate valve 1 has two valve bodies that are spaced apart from a high pressure side valve body 2 and a low pressure side valve body 3 that open and close the communication passage 9. An interspace 4 is formed. Both valve bodies 2 and 3 are installed inside the outer frame 6 so as to be slidable along the guide rail 7, and have a structure that slides in conjunction with each other by a connecting operating rod 5. A sealing material 8 is installed at a sliding portion of the outer frame 6 with the operating rod 5, and airtightness is maintained even when the operating rod 5 is slid by an operating motor (not shown).

  A pressure sensor 14 that measures the pressure in the inter-valve space 4 and the high-pressure side communication passage 9a and detects the pressure difference is provided, and a control device 15 that performs control based on the detection data is provided.

  The inter-valve space 4 and the low-pressure side communication passage 9b can communicate with each other through a gas supply passage 11 provided with a supply pump 10 in the middle. The supply amount of the supply pump 10 is controlled by the control device 15.

  When the slide gate valve 1 is closed, the valve bodies 2 and 3 are slid together with the slide of the operating rod 5 to be in a closed state as shown in FIG. In this embodiment, both valve bodies 2 and 3 are connected to each other and slide in conjunction with each other, but may be structured to slide individually.

  In the closed state, the communication passage 9 is blocked by the two valve bodies 2 and 3, but the clearance between the two valve bodies 2 and 3 is completely removed due to manufacturing errors of parts, deterioration over time and wear. Without this, the flow of the gas a2 from the high pressure side communication path 9a to the low pressure side communication path 9b cannot be stopped.

  Therefore, based on the detection data of the pressure difference between the inter-valve space 4 detected by the pressure sensor 14 and the high-pressure side communication passage 9a, the gas supply amount of the supply pump 10 is controlled so as to reduce this pressure difference. The gas a1 is supplied to the inter-valve space 4 from the side communication passage 9b. By this control, the pressure difference between the inter-valve space 4 and the high-pressure side communication passage 9a can be made minute to almost prevent the flow of the gas a2 from the high-pressure side communication passage 9a into the inter-valve space 4.

  On the other hand, the pressure difference between the inter-valve space 4 and the low-pressure side communication passage 9b increases, and the inflow of gas from the inter-valve space 4 to the low-pressure side communication passage 9b increases. However, since most of the inter-valve space 4 occupies the gas a1 of the low-pressure side communication passage 9b supplied by the supply pump 10, it substantially passes through both valve bodies 2 and 3 and passes through the high-pressure side communication passage. The amount of the gas a2 flowing from 9a to the low pressure side communication passage 9b becomes a very small amount flowing into the inter-valve space 4 from the high pressure side communication passage 9a.

  The amount of gas inflow is proportional to the square root of the pressure difference. Therefore, for example, when the pressure difference between the high pressure side communication passage 9a and the low pressure side communication passage 9b is 20 mmAq, the pressure difference between the inter-valve space 4 and the high pressure side communication passage 9a is 2 mmAq and the inter-valve space 4 is controlled by this control. If the pressure difference with the low-pressure side communication path 9b is 18 mmAq, the amount of gas a2 flowing from the high-pressure side communication path 9a into the low-pressure side communication path 9b is proportional to the square root of the pressure difference 2 mmAq.

  On the other hand, when the valve is simply closed by two valve bodies without performing this control, the pressure in the inter-valve space 4 becomes the average value of the high-pressure side communication path 9a and the low-pressure side communication path 9b, and the inter-valve space 4 and the pressure difference between the high pressure side communication path 9a and the pressure difference between the inter-valve space 4 and the low pressure side communication path 9b are 10 mmAq. Therefore, the inflow amount of the gas a2 from the high pressure side communication path 9a to the low pressure side communication path 9b is proportional to the square root of the pressure difference of 10 mmAq.

  That is, the inflow amount can be suppressed by 50% or more by the slide gate valve 1 of the present invention. This effect increases as the pressure difference between the high-pressure side communication path 9a and the low-pressure side communication path 9b increases.

  Further, in the present invention, since the gas flow is prevented by reducing the pressure difference, there is a clearance when the valve is closed due to sliding by opening and closing the valve bodies 2 and 3 repeatedly, wear of the contact portion, biting of foreign matter, and the like. Even if it increases, the effect of preventing the flow of gas from the high-pressure side communication path 9a to the low-pressure side communication path 9b is not affected. That is, this effect can be reliably maintained for a long time. By providing a seal material at the part where both valve bodies 2 and 3 come into contact when the valve is closed, the generation of gaps can be suppressed.

  When the slide gate valve 1 is opened, the supply pump 10 is stopped to stop supplying unnecessary gas to the inter-valve space 4. At this time, the control device 15 controls the operation and stop of the supply pump 10 according to the opening / closing operation of the operating rod 5 that opens and closes the slide gate valve 1 or the operating motor (not shown) that operates the operating rod 5. It can also be.

  Alternatively, as shown in FIG. 2, a switching valve 12 is provided on the downstream side of the supply pump 10 of the gas supply path 11 so that the switching valve 12 and the upstream side of the supply pump 10 of the gas supply path 11 can communicate with each other. A gas circulation path 13 may be provided. The gas circulation path 13 may be provided so as to communicate the switching valve 12 and the low pressure side communication path 9b.

  When the slide gate valve 1 is opened with this structure, the switching valve 12 is switched and the gas a1 supplied to the inter-valve space 4 is circulated through the gas circulation path 13. By controlling the switching of the switching valve 12 by the control device 15 in accordance with the opening / closing operation of the operating rod 5 that opens and closes the slide gate valve 1 or the operating motor 16 that operates the operating rod 5, an automated system can be realized.

  Next, the double damper 19 of the present invention will be described based on the embodiment shown in the drawings. FIG. 3 illustrates an overall outline of the double damper 19. Two slide gate valves 1a and 1b of the present invention are connected to a communication passage 9 having a pressure difference at a predetermined interval, and are connected to a high pressure side communication passage 9a (upper side in the drawing) and a low pressure side communication passage 9b (in the drawing). The lower side) and a damper space 17 is formed between the slide gate valves 1a and 1b.

  The high-pressure side slide gate valve 1a is supplied to the damper space 17 by the supply pump 10 based on the pressure difference between the high-pressure side communication path 9a and the damper space 17 detected by the pressure sensor 14 with both the slide gate valves 1a and 1b closed. The supply amount of the gas b2 supplied to the inter-valve space 4 is controlled to reduce this pressure difference.

  The low pressure side slide gate valve 1b is connected to the low pressure side communication by the supply pump 10 based on the pressure difference between the low pressure side communication passage 9b and the damper space 17 detected by the pressure sensor 14 with both the slide gate valves 1a and 1b closed. The supply amount of the gas b2 supplied from the passage 9b to the inter-valve space 4 is controlled to reduce this pressure difference. The details are the same as those of the slide gate valve 1 of the present invention described above, and it is possible to prevent gas from flowing from the high pressure side to the low pressure side of the communication passage 9 when both the slide gate valves 1a and 1b are closed. At the same time, this effect can be maintained reliably and over a long period of time.

  The double damper 19 opens and closes the slide gate valves 1a and 1b alternately from the high pressure side when charging or discharging discharged materials into the communication passage 9 according to the loading and discharging. Gas distribution to the low pressure side can be prevented. That is, gas flow can be prevented when the slide gate valves 1a and 1b are opened, and by using the slide gate valve 1 of the present invention, gas flow can be prevented when the slide gate valve 1 is closed and opened. It becomes possible to prevent.

  In this embodiment, the slide gate valve 1 of the present invention is used for both slide gate valves 1a and 1b. However, as shown in FIG. 4, the high pressure side is a general slide gate valve 18, and the low pressure side is the present invention. The slide gate valve 1 may be used. Further, the arrangement may be reversed, and by using one of the slide gate valves 1 of the present invention, an excellent gas flow prevention effect can be obtained when the slide gate valve 1 is closed and opened. Can do.

  As an apparatus using this double damper 19, an embodiment of the pyrolysis gasification apparatus of the present invention is illustrated in FIG.

  This apparatus is a moving bed type pyrolysis gasification apparatus that gasifies waste by pyrolysis or the like in a low-oxygen atmosphere. A vertical inlet 26 is provided at the top and a product gas discharge passage 21 is provided above. A gasification furnace 20 of the type is provided. Above the input port 26, a waste hopper 23 for storing the waste to be burned and a granular incombustible pellet such as pumice and ceramics that form a moving bed for improving the air permeability in the gasification furnace 20 And a pellet hopper 22 for storing the.

  The waste hopper 23 is provided with a double damper 19 in the upper communication path 9 and a screw feeder 25 in the lower part. The pellet hopper 22 is provided with a double damper 19 in the upper communication path 9 and a feeder 24 in the lower part.

  A table feeder 29 fixed to a rotary shaft 31 rotated by a rotary drive motor 28 is provided at the bottom of the gasification furnace 20, and a residue discharge chamber 27 having a double damper 19 is provided adjacent to the table feeder 29. Yes. The rotating shaft 31 is provided with a gas supply hole 30 so that air or the like and water vapor can be injected radially into the gasification furnace 20.

  On the side surface of the gasification furnace 20, a plurality of temperature sensors 32, a plurality of in-furnace pressure sensors 34, and a level sensor 33 for detecting the level of filled waste or the like are disposed at appropriate positions.

  The waste is introduced from the waste hopper 23 into the gasification furnace 20 through the inlet 26 by the screw feeder 25. The nonflammable pellets are fed from the pellet hopper 22 to the gasification furnace 20 through the charging port 26 by the charging machine 24.

    Since the inside of the gasification furnace 20 is set to a slight negative pressure or a slightly positive pressure, a double damper 19 is provided in the communication passage 9 above both the hoppers 22 and 23 to replenish waste and nonflammable pellets. Therefore, the flow of gas when the slide gate valve 1 is opened is prevented. When the gasification furnace 20 has a slight negative pressure, the outside air flows into the gasification furnace 20 and the quality of the product gas G decreases. When the gasification furnace 20 has a slight positive pressure, the product gas G is in the atmosphere. This is because it will flow out.

  Therefore, when the slide gate valve 1 of the present invention is used, the gas flow can be prevented as described above even in the closed state, and the effect can be maintained reliably and in the long term.

  When waste and incombustible pellets are charged, filled and ignited in the gasification furnace 20, a part of the waste is caused by air or the like supplied from the gas supply hole 30 of the rotary shaft 31 at the bottom of the gasification furnace 20. Combustion body A3 of about 1000 ° C., for example, is formed by combustion. Here, the flowability of air or the like is ensured by nonflammable pellets. In a steady state, this combustor A3 is formed at a stable position, a pyrolysis zone A2 of a reducing atmosphere is formed above it, and a dry zone A1 is further formed above it. Below the combustion zone A3, the layer composed of the combustion residue D burned down is cooled by the air supplied from the gas supply holes 30 and becomes the cooling zone A4.

In the pyrolysis zone A2, the waste is pyrolyzed into combustible pyrolysis gas, carbon (char), and nonflammable residue D. A part of the generated char reacts with water vapor supplied from the gas supply hole 30 to generate water gas (CO, H ₂ ).

  The residue D is discharged by the table feeder 29 through the residue discharge chamber 27 to the outside of the apparatus. In this case as well, a double damper 19 is provided in order to prevent gas from flowing when the slide gate valve 1 is opened in the communication passage 9 having a pressure difference, as in the case of putting wastes into the hoppers 22 and 23. It has been. Here, by using the double damper 19 of the present invention, gas flow can be prevented not only when the slide gate valve 1 is opened but also when the valve is closed, and the effect is maintained reliably and in the long term. can do.

  The product gas G composed of the pyrolysis gas and the water gas dries the waste when it rises through the gap of the waste above the pyrolysis zone A2, so that a dry zone A1 is formed. The gas G is cooled to about 200 ° C., for example, and discharged from the product gas discharge path 21 and is effectively used as fuel gas or the like.

  In such a pyrolysis gasification apparatus, since the period during which the operation of the apparatus can be stopped and maintenance can be restricted, the double damper 19 of the present invention that can maintain the effect of preventing gas flow for a long time is preferably used. Can be used.

  In this example, in a pyrolysis gasifier that thermally decomposes and gasifies waste in a low-oxygen atmosphere, an input system that inputs waste, pellets, and the like into the gasification furnace 20, and an exhaust system that discharges combustion residues, Although the double damper 19 of the present invention is used for both of these systems, the double damper 19 of the present invention may be used for at least one of the systems.

It is a longitudinal cross-sectional view which shows an example of the slide gate valve of this invention. It is a longitudinal cross-sectional view which shows the other example of the slide gate valve of this invention. It is a longitudinal cross-sectional view which shows an example of the double damper of this invention. It is a longitudinal cross-sectional view which shows the other example of the double damper of this invention. It is a longitudinal cross-sectional view which shows an example of the thermal decomposition gasification apparatus of this invention.

Explanation of symbols

1 Slide gate valve (of the present invention)
1a (invention) high pressure side slide gate valve
1b (invention) low pressure side slide gate valve
2 High pressure side valve body 3 Low pressure side valve body 4 Space between valve bodies
5 Operating rod 6 Outer frame 7 Guide rail 8 Sealing material
DESCRIPTION OF SYMBOLS 9 Communication path 9a High pressure side communication path 9b Low pressure side communication path 10 Supply pump 11 Gas supply path 12 Switching valve 13 Gas circulation path 14 Pressure sensor 15 Control device 16 Actuator motor 17 Damper space 18 General slide gate valve 19 Double damper 20 Gasification furnace 21 Generated gas discharge passage
22 Pellet hopper 23 Waste hopper
24 Pellet feeder 25 Screw feeder
26 Input path 27 Residue discharge chamber 28 Rotation drive motor 29 Table feeder 30 Gas supply hole 31 Rotating shaft 32 Temperature sensor 33 Level sensor 34 In-furnace pressure sensor

Claims (5)

  A slide gate valve that opens and closes a communication path having a pressure difference, wherein two slidable valve bodies that open and close the communication path are arranged apart from each other, and the pressure between the valve bodies and the both of the communication paths are A pressure sensor for detecting a pressure difference with respect to a pressure on a higher pressure side than the valve body, a supply pump for supplying a gas on a lower pressure side than the both valve bodies of the communication path between the valve bodies, and the both valve bodies And a control device for reducing the pressure difference by controlling the gas supply amount from the supply pump based on the pressure difference detected by the pressure sensor in the closed state.   The slide gate valve according to claim 1, wherein the two valve bodies are connected so as to be interlocked.   3. The slide gate valve according to claim 1, further comprising a circulation path for switching and circulating the gas supplied between the valve bodies by the supply pump to a lower pressure side than the both valve bodies of the communication path.   In the double damper which connects two slide gate valves to the communicating path with a pressure difference at predetermined intervals, at least one of the slide gate valves is the slide gate valve according to any one of claims 1 to 3. Double damper characterized by that.   A gasification furnace that thermally decomposes and gasifies waste in a low-oxygen atmosphere, a waste input system that inputs waste through a communication passage having a pressure difference in the gasification furnace, and a waste that is input from the gasification furnace 5. A pyrolysis gasification apparatus comprising a residue discharge system for discharging a combustion residue of a waste through a communication passage having a pressure difference, wherein at least one of the waste input system and the residue discharge system includes A pyrolysis gasifier having a heavy damper.

Images