JP2007039493A - Gas reformer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas reformer which enables stable continuation of the treatment of waste materials over a long period without causing clogging of the oven bed in a gas reforming oven with carbon ashes. <P>SOLUTION: The gas reformer has an ash discharge screw 6 for transferring carbon ashes 14 to a predetermined discharge part 15 provided on the bottom surface of an intermediate part of a gas reforming oven having a thermal decomposition burner 2 for mixing a thermal decomposition gas 1 with combustion air 3 to burn the mixed gas in a low oxygen state, and the build-up amount of the carbon ashes 14 relative to a screw shaft 7 of the ash discharge screw 6 is estimated, and when the estimated build-up amount of the carbon ashes 14 comes to the previously set relationship with the screw shaft 7, the screw shaft 7 is operated in the direction of discharge of the carbon ashes 14. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a gas reforming apparatus for reforming pyrolysis gas generated by pyrolysis treatment of exhaust.

  Conventionally, as a waste treatment system that processes unsorted and untreated waste containing various pollutants and transforms them into usable materials, waste that is thermally decomposed and gas is reformed A processing system is known (see, for example, Patent Document 1).

This waste disposal system will be described with reference to FIG. In the waste treatment system, the waste 101 is crushed and separated by the pretreatment device 102, and is sent to the external heating type pyrolysis furnace 104 by the waste supply device 103 to be in a so-called steamed state at about 500 to 600 ° C. Thermally decomposes. The workpiece is decomposed into pyrolysis gas and residue in the pyrolysis furnace 104. Among these, the residue passes through the residue discharging device 105, is granulated by the granulating device 106, and finally is recycled as a reducing material such as an electric furnace. On the other hand, the gas decomposed in the pyrolysis furnace 104 is burned in a low oxygen state at about 1000 to 1200 ° C. in the gas reforming furnace 107 and reformed. Thereafter, the gas purifier 108 cools the gas, removes the carbon powder, and cleans the gas to generate a combustible gas, which is effectively used as a fuel for the pyrolysis furnace 104 or a gas engine.
Japanese Patent Publication No.8-24904

  By the way, in such a waste treatment system, it is desired that the pyrolysis gasification reforming treatment is performed continuously and stably for a long time.

  However, when waste treatment is performed for a long time, carbon ash (soot) that was not accompanied by the gas flow is deposited on the inner floor of the gas reforming furnace. As a result, it was assumed that the floor of the gas reforming furnace was blocked with carbon ash, the gas flow was hindered, and the waste treatment could not be continued.

  An object of the present invention is to provide a gas reforming apparatus that eliminates the blockage of carbon ash in the hearth of a gas reforming furnace, and can continue the treatment of waste for a long period of time.

  The gas reforming apparatus of the present invention transfers carbon ash to a predetermined discharge section on the bottom of an intermediate section of a gas reforming furnace having a pyrolysis burner at one end and a gas discharge pipe connected to the other end. A gas reforming apparatus provided with an ashing screw that performs deposition amount estimation means for estimating the amount of carbon ash deposited on the screw shaft of the ashing screw, and the estimated amount of carbon ash deposition is the screw shaft And a screw shaft operating means for operating the screw shaft in the carbon ash discharge direction on condition that the relationship is set in advance.

  In the present invention, the accumulation amount estimation means detects the amount of elongation of the screw shaft, and estimates the accumulation state of carbon ash on the screw shaft from the amount of elongation.

  In the present invention, the accumulation amount estimation means detects the vibration propagation time of the screw shaft, and estimates the carbon ash accumulation state on the screw shaft from the vibration propagation time.

  In the present invention, the accumulation amount estimation means detects the bending natural frequency of the screw shaft, and estimates the accumulation state of carbon ash on the screw shaft from the bending natural frequency.

  In the present invention, the accumulation amount estimation means detects the damping coefficient of the bending vibration of the screw shaft, and estimates the accumulation state of carbon ash on the screw shaft from the bending coefficient of the bending vibration.

  In the present invention, the accumulation amount estimation means detects the torque of the motor that drives the screw shaft, and estimates the accumulation state of carbon ash on the screw shaft from this torque.

  Further, in the present invention, the deposition amount estimation means measures the pressure in the furnace at one end and the other end across the intermediate portion of the gas reforming furnace, and the carbon ash deposition state on the screw shaft from the pressure loss of the difference Is estimated.

Further, in the present invention, the screw shaft operating means causes the screw shaft to move at regular intervals if the estimated amount of carbon ash accumulation by the accumulation amount estimating means is in a state before the relationship set in advance with respect to the screw shaft. Further, in the present invention, the screw shaft operating means is configured so that the estimated amount of carbon ash accumulated by the accumulated amount estimating means has a preset relationship with respect to the screw shaft. The rotational speed of the screw shaft is controlled.

  According to the present invention, since a certain amount of carbon ash in the gas reforming furnace is accumulated and the screw shaft is covered with carbon ash for discharge operation, the hearth of the gas reforming furnace is blocked with carbon ash. It is possible to prevent the waste and to continue the disposal of the waste for a long time.

  Hereinafter, an embodiment of a gas reforming apparatus according to the present invention will be described in detail with reference to the drawings.

  In FIG. 1, reference numeral 4 denotes a gas reforming furnace, which includes a pyrolysis burner 2 which mixes pyrolysis gas 1 with combustion air 3 at one end and burns it in a low oxygen state (incomplete combustion), and a gas at the other end. The discharge pipe 5 is connected and has a substantially J shape. That is, a substantially J-shape consisting of a front reaction column 4a provided with a pyrolysis burner 2 at the top, a post reaction column 4b provided with a gas discharge pipe 5 at the upper end, and a lateral intermediate portion 4c communicating these lower ends. The ashing screw 6 is provided on the bottom surface of the intermediate portion 4c. The ashing screw 6 discharges the carbon ash 14 generated with the incomplete combustion of the pyrolysis gas 1 from the bottom surface of the intermediate portion 4c.

  The ashing screw 6 is made of a material that can withstand high temperatures, and the screw shaft 7 is rotatably supported at both ends by bearings 8 and 9 and high-temperature seals 10 and 11. The screw shaft 7 is connected to a drive motor 13 via a joint 12 and is rotationally driven by the drive motor 13. And the carbon ash 14 is transferred to the predetermined discharge part 15 by the rotation, and is discharged out of the furnace.

  The discharge unit 15 has a partition damper 15a, and the carbon ash 14 transferred by the ash extraction screw 6 passes through the partition damper 15a and is sent to the carbon cooling screw 16. The carbon cooling screw 16 has a screw shaft 17 and a casing 18, and the screw shaft 17 is rotatably supported by bearings 19 and 20. Further, a seal 21 is provided inside the bearing 20, and the screw shaft 17 is rotationally driven by a drive motor 22 connected to the left end in the drawing.

  The casing 18 is provided with a discharge portion 23 at the inner bottom portion of the seal 21, and the carbon ash 14 cooled while being sent to the left in the figure by the carbon cooling screw 16 is ashed from the discharge portion 23 to the recovery can 25. It is. In the discharge part 23, dampers 23a and 23b that are always closed are provided, and the carbon ash 14 is discharged to the recovery can 25 while blocking external air by the dampers 23a and 23b.

  In the above configuration, the pyrolysis gas 1 gasified in a preceding pyrolysis furnace (not shown) is mixed with the combustion air 3 in the pyrolysis burner 2 and burns in an incomplete state in the reforming furnace 4. The purpose of gas reforming is to convert a pyrolysis gas composed of high molecular weight hydrocarbons into a low molecular weight combustible gas, which is set to a very high temperature of 1000 to 1200 ° C. Therefore, the inner wall of the gas reforming furnace 4 is made of a refractory material. In the temperature control in the furnace, for example, the temperature in the furnace is measured by the thermometer 30 and is controlled so as to become a set target temperature.

  An ash removal screw 6 is installed on the floor of the gas reforming furnace 4 and is driven by a drive motor 13 to discharge the carbon ash 14 out of the furnace. That is, the carbon ash 14 passes through the partition damper 15 a of the discharge unit 15 and is sent to the carbon cooling screw 16. The carbon cooling screw 16 is rotationally driven by a drive motor 22 to move the carbon ash 14 while cooling, and the recovery can 25 while blocking external air by the dampers 23a and 23b of the discharge portion 23, which is always closed. To be discharged.

  Here, when operating the ashing screw 6, it is possible to reduce the temperature of the ashing screw 6 and prevent its wear and breakage by operating the screw shaft 7 covered with the carbon ash 14. It was found. Therefore, in the present invention, the carbon ash 14 is accumulated on the floor of the gas reforming furnace 4, the amount of carbon ash 14 deposited is estimated, and the ash extraction operation can be performed with the carbon ash 14 covering the screw shaft 7. Configured.

  That is, the accumulation amount estimation means 51 for estimating the accumulation amount of the carbon ash 14 with respect to the screw shaft 7 and the estimated accumulation amount of the carbon ash 14 by the accumulation amount estimation means 51 with respect to the screw shaft 7 (screw The screw shaft operating means 52 for operating the screw shaft 7 in the discharge direction of the carbon ash 14 is provided on the condition that the accumulation level capable of covering the shaft 7 is reached.

  In the example of FIG. 1, the accumulation amount estimation means 51 detects the amount of elongation of the screw shaft 7 and estimates the accumulation state of the carbon ash 14 on the screw shaft 7 from the amount of elongation. For this reason, a displacement meter 27 capable of measuring the axial extension amount 26 is attached to the counter drive side shaft end (the left end in the drawing) of the screw shaft 7 with a jig 28. The screw shaft 7 of the ashing screw 6 installed in the furnace is rotatably supported by bearings 8 and 9 at both ends. Of these, the bearing 8 fixes the screw shaft 7 in the axial direction, but the bearing 9 is movable in the axial direction as the screw shaft 7 extends, and the amount of axial extension by the displacement meter 27 is increased. Measurement is possible.

  Next, the effect | action of this Embodiment which consists of such a structure is demonstrated using FIG. 1 and FIG.

  In FIG. 1, when the screw shaft 7 is buried in the carbon ash 14, the screw shaft 7 is cut off from the reaction gas, and since it does not receive direct radiant heat from the combustion flame of the burner 2, the temperature of the shaft is lowered and the shaft is extended. The amount becomes smaller. The amount of axial elongation is detected by the displacement meter 27, and the amount of carbon ash 14 deposited is estimated by the amount of deposit estimation means 51 based on the detection result. The screw shaft operating means 52 controls the drive motor 13 to perform the ashing operation so that the axial elongation amount in a state where the screw shaft 7 is buried with the carbon ash 14 is constant or within a limited range. As a result, the screw shaft 7 can be protected from a high temperature atmosphere.

  FIG. 2 shows the relationship between the screw shaft temperature, material strength, wear, and shaft elongation. In FIG. 2, when the temperature of the screw shaft 7 is increased to the atmospheric temperature in the gas reforming furnace 4: 1000 to 1200 ° C., the material strength is extremely lowered and the wear is extremely increased. On the other hand, the axial elongation increases almost in proportion to the temperature.

  From these relationships, while measuring the amount of elongation of the screw shaft 7 and estimating the amount of carbon ash 14 accumulated, the screw shaft (main shaft) 7 is always covered with the carbon ash 14 and the temperature is lowered to perform the ash extraction operation. This is very effective for ensuring the strength of the shaft and reducing wear.

  On the other hand, the pressure in the system is sucked with an induction blower attached to the rear stage of the gas purification device (not shown) connected to the gas discharge pipe 5 in FIG. . Under such pressure control, if the carbon ash 14 is accumulated too much in the gas reforming furnace 4, the gas flow may be hindered. However, as described above, it is possible to prevent clogging by the carbon ash 14 by estimating the amount of carbon ash 14 deposited and performing the ashing operation of the ashing screw 6.

  With the above configuration, a certain amount of the carbon ash 14 in the gas reforming furnace 4 is accumulated, and the screw shaft 7 is covered with the carbon ash 14 to be discharged. It is possible to prevent the portion from being clogged with the carbon ash 14 and to continue the waste treatment stably over a long period of time.

  Next, the embodiment shown in FIG. 3 will be described. FIG. 3 shows the ashing screw 6 installed at the bottom of the gas reforming furnace 4 taken out. At both ends of the screw shaft 7 of the ashing screw 6, vibration acceleration sensors 31 and 32 with a built-in FM transmitter are attached. The vibration acceleration sensors 31 and 32 are configured to receive a vibration waveform measured via the receiving antenna 33 and input the vibration waveform to the vibration / torque detection circuit 34.

  In such a configuration, when an impact is applied from the shaft end (right end in the drawing) of the screw shaft 7 using a hammer or the like, a vibration waveform as shown in FIG. 4 is detected. The vibration waveform A1 is a waveform detected by the vibration acceleration sensor 31, and the vibration waveform A2 is a waveform detected by the vibration acceleration sensor 32. Since the waveform A1 detected by the vibration acceleration sensor 31 is close to the hit position, the P wave and the S wave rise at the same time, and only the S wave is detected. The waveform A2 detected by the vibration acceleration sensor 32 transmits the P wave quickly, and then the bending vibration (corresponding to the S wave) of the screw shaft 7 is detected. This vibration propagation time τ changes approximately in proportion to the square root of the Young's modulus E of the screw shaft.

  The relationship is shown in FIG. When the main shaft temperature of the in-furnace screw 6 increases, the material becomes soft, the Young's modulus E decreases, and the speed of vibration propagation through the screw shaft 7 decreases. As a result, a time difference appears in the waveforms detected at both ends of the axis. This time difference is the vibration propagation time τ.

  If a certain amount of the carbon ash 14 in the gas reforming furnace 4 is accumulated and the discharge operation is performed with the screw shaft 7 covered with the carbon ash 14, the temperature of the screw shaft 7 decreases and the vibration propagation speed τ becomes short. Become.

  Therefore, the amount of carbon ash 14 deposited can be estimated by measuring the vibration propagation speed τ of the screw shaft 7 by the vibration / drive torque detection circuit 34 shown in FIG. That is, the vibration / drive torque detection circuit 34 functions as a deposit amount estimation unit. In this way, the ashing screw 6 can be operated and controlled while the carbon ash 14 covers the screw shaft 7 while estimating the amount of carbon ash 14 deposited from the vibration propagation speed τ. Therefore, the temperature of the main shaft 7 can be constantly lowered to perform the ash removal operation, which is very effective for ensuring the strength of the shaft 7 and reducing wear.

  Further, since the ashing screw 6 is operated while maintaining the amount of carbon ash 14 deposited so as to cover the screw shaft 7 as described above, the carbon ash 14 does not accumulate too much in the gas reforming furnace 4, and the gas Blockage in the reforming furnace 4 can be prevented.

  Next, the case where it controls by the natural frequency with respect to the vibration mode 39 of the screw shaft 7 is demonstrated. The vibration / drive torque detection circuit 34 functioning as a deposit amount estimation means detects the natural bending frequency of the screw shaft 7, estimates the carbon ash accumulation state on the screw shaft 7 from the natural bending frequency, and the estimation result. The ashing screw 6 is controlled according to the operation.

  Here, if the vibration detection waveforms A1 and A2 shown in FIG. 4 are frequency-analyzed, the natural frequency for the vibration mode 39 of the screw shaft 7 can be obtained. This vibration corresponds to the bending natural frequency of the screw shaft 7, and as shown in FIG. 2, when the temperature of the screw shaft 7 becomes high, the material becomes soft, so that the natural frequency decreases.

  Therefore, by measuring the bending natural frequency of the screw shaft 7 and estimating the accumulation amount of the carbon ash 14, the ashing screw 6 can be operated and controlled with the carbon ash 14 covering the screw shaft 7. For this reason, the temperature of the main shaft 7 can be constantly lowered to perform the ashing operation, which is very effective for ensuring the strength of the shaft 7 and reducing wear.

  Further, since the ashing screw 6 is operated while maintaining the amount of carbon ash 14 deposited so as to cover the screw shaft 7, the carbon ash 14 does not accumulate in the gas reforming furnace 4 and the gas Blockage in the reforming furnace 4 can be prevented.

  Next, the case where it controls by the vibration damping coefficient with respect to the vibration mode 39 of the screw shaft 7 is demonstrated. A vibration attenuation coefficient for the vibration mode 39 of the screw shaft 7 can be obtained from the vibration detection waveforms A1 and A2 by the vibration / drive torque detection circuit 34 functioning as a deposit amount estimation means. This vibration corresponds to the natural bending frequency of the screw shaft 7, and when the carbon ash 14 is deposited, the carbon ash 14 becomes an additional mass, and a change appears in the vibration damping coefficient.

  Therefore, by measuring the damping coefficient of the natural bending vibration of the screw shaft 7 and estimating the accumulation amount of the carbon ash 14, the ashing screw 6 can be operated and controlled with the carbon ash 14 covering the screw shaft 7. For this reason, the temperature of the main shaft can be always lowered and the ashing operation can be performed, which is very effective for ensuring the strength of the shaft and reducing wear.

  Also in this case, since the ashing screw 6 is operated while maintaining the amount of carbon ash 14 deposited so as to cover the screw shaft 7, the carbon ash 14 does not accumulate in the gas reforming furnace 4, and the gas reforming is not performed. Blockage in the quality furnace 4 can be prevented.

  Next, the case where it controls by the motor torque of the drive motor 13 of the screw shaft 7 is demonstrated. The vibration / drive torque detection circuit 34 functioning as a deposit amount estimation means detects the motor torque of the drive motor 13 and estimates the deposit amount of the carbon ash 14. That is, when the screw shaft 7 is covered with the carbon ash 14, the carbon ash 14 becomes a resistance and the torque of the drive motor 13 increases. This motor torque is measured to estimate the amount of carbon ash 14 deposited.

  Thus, since the amount of carbon ash 14 accumulated can be estimated by measuring the motor torque of the drive motor 13, the ashing screw 6 can be operated and controlled with the carbon ash 14 covering the screw shaft 7. . For this reason, the temperature of the main shaft 7 can always be lowered and the ashing operation can be performed, which is very effective for ensuring the strength of the shaft and reducing wear.

  Next, a case where control is performed using pressure loss in the reforming path 4 will be described. In FIG. 1, if the carbon ash 14 continues to accumulate at the bottom of the gas reformer 4, this portion is blocked by the carbon ash 14, and the gas flow cannot be secured. Therefore, the in-furnace pressure P1 of the pre-reaction tower 4a and the in-furnace pressure P2 of the post-reaction tower 4b are measured by pressure gauges 40 and 41. Before the above-described blockage by the carbon ash 14 occurs, a large difference occurs in the furnace pressures P1 and P2. That is, the passage through which the gas flows becomes narrow due to the deposition of the carbon ash 14, and the pressure loss increases.

  Therefore, when the in-furnace pressure P1 of the pre-reaction tower 4a and the in-furnace pressure P2 of the post-reaction tower 4b are measured, and the difference is taken as a pressure loss, the amount of carbon ash deposited can be estimated from the magnitude of the pressure loss. Since the amount of carbon ash 14 deposited can be estimated in this way, the ashing screw 6 can be operated and controlled with the carbon ash 14 covering the screw shaft 7. For this reason, the temperature of the main shaft 7 can always be lowered and the ashing operation can be performed, which is very effective for ensuring the strength of the shaft and reducing wear.

  In each of the embodiments described above, if the amount of ash discharged is greater than the amount deposited, the amount of ash deposited is reduced. If this is continued, the screw shaft 7 is not covered from the carbon ash 14. To prevent this, the amount of axial extension of the screw shaft, the vibration propagation time (propagation speed) of the screw shaft, the natural bending frequency of the screw shaft, the damping coefficient of the bending vibration of the screw shaft, the torque of the motor that drives the screw shaft Ashes are carried out while observing any one of the monitoring means for the pressure loss of the pre-reaction tower and the post-reaction tower, and when the predetermined amount of ash is reached, the screw shaft 7 may be operated alternately in the forward direction and the reverse direction. By this operation, the screw shaft 7 is not left standing and can be prevented from being bent due to thermal deformation.

  Also, the amount of elongation of the screw shaft, the vibration propagation time (propagation speed) of the screw shaft, the natural bending frequency of the screw shaft, the damping coefficient of the bending vibration of the screw shaft, the torque of the motor driving the screw shaft, While looking at any one of the monitoring means for the pressure loss of the post-reaction tower, the speed of the drive motor 13 is controlled by an inverter or the like, and the carbon discharge control is performed so that a certain amount of carbon ash 14 is accumulated in the gas reforming furnace 4. May be.

  This means makes it possible to deposit a substantially constant amount of carbon ash 14, and it is very effective to ensure the strength of the shaft and reduce wear by always lowering the temperature of the main shaft and performing the ash removal operation. is there.

  With the above configuration, a certain amount of carbon ash 14 in the gas reforming furnace 4 is accumulated, and the screw shaft 7 is covered with the carbon ash 14 and discharged. Can be prevented from being clogged with carbon ash, and the treatment of waste can be continued stably over a long period of time.

It is a lineblock diagram showing one embodiment of a gas reforming device by the present invention. It is a characteristic view explaining the present invention. It is a block diagram which shows other embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. It is a block diagram explaining a prior art.

Explanation of symbols

2 Pyrolysis Burner 4 Gas Reforming Furnace 5 Gas Discharge Pipe 6 Ashing Screw 7 Screw Shaft 13 Drive Motor 14 Carbon Ash 15 Discharge Part 27 Axial Elongation Sensors 31, 32 Vibration Acceleration Sensor 51 Accumulated Accumulation Means 52 Screw Shaft Operating Means

Claims (9)

A gas reformer provided with an ashing screw for transferring carbon ash to a predetermined discharge part on the bottom of the intermediate part of the gas reforming furnace having a pyrolysis burner at one end and a gas discharge pipe connected to the other end. Quality device,
A deposition amount estimating means for estimating a deposition amount of the carbon ash with respect to a screw shaft of the ashing screw;
A screw shaft operating means for operating the screw shaft in the carbon ash discharge direction on the condition that the estimated amount of carbon ash accumulation is a preset relationship with the screw shaft;
A gas reforming apparatus comprising:   The gas reforming apparatus according to claim 1, wherein the accumulation amount estimation means detects the amount of elongation of the screw shaft and estimates the accumulation state of carbon ash on the screw shaft from the elongation amount.   The gas reforming apparatus according to claim 1, wherein the accumulation amount estimation means detects a vibration propagation time of the screw shaft and estimates a carbon ash accumulation state on the screw shaft from the vibration propagation time.   The gas reforming apparatus according to claim 1, wherein the accumulation amount estimation means detects a bending natural frequency of the screw shaft, and estimates a carbon ash accumulation state on the screw shaft from the bending natural frequency.   2. The gas reforming according to claim 1, wherein the accumulation amount estimation means detects a damping coefficient of the bending vibration of the screw shaft, and estimates a deposition state of carbon ash on the screw shaft from the damping coefficient of the bending vibration. apparatus.   The gas reforming apparatus according to claim 1, wherein the accumulation amount estimation means detects a torque of a motor that drives the screw shaft, and estimates a carbon ash accumulation state on the screw shaft from the torque.   The deposit amount estimation means measures the pressure in the furnace at one end and the other end across the middle of the gas reforming furnace, and estimates the accumulation state of carbon ash on the screw shaft from the pressure loss of the difference. The gas reformer according to claim 1.   If the estimated amount of carbon ash accumulated by the accumulated amount estimating means is in a state before the relationship set in advance with respect to the screw shaft, the screw shaft operating means moves the screw shaft in the normal direction and the reverse direction at regular intervals. The gas reforming apparatus according to claim 1, wherein the gas reforming apparatus is repeatedly operated.   The screw shaft operating means controls the rotational speed of the screw shaft so that the estimated amount of carbon ash accumulation by the accumulation amount estimating means has a preset relationship with respect to the screw shaft. The gas reformer according to any one of claims 1 to 7.

Images