JP2010096444A - Carbonization gasification furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To promote formation of a hearth without causing abnormal combustion due to excessive oxygen in a furnace in a carbonization gasification furnace carbonizing a residual part of waste by combustion heat while burning one part of the waste to produce combustible gas, and equipped with an ignition means 6 for igniting the waste in an ignition port 5 formed in a lower part of the carbonization gasification furnace, and a first oxygen supplying means 7 for supplying oxygen from a furnace bottom in the carbonization gasification furnace. <P>SOLUTION: A second oxygen supplying means 8 is provided for supplying oxygen from at least one of the ignition port 5 in the carbonization gasification furnace 1 or a portion adjacent to the ignition port 5. Even during operation of the ignition means 6 or after igniting waste and stopping the operation of the ignition means 6, oxygen is supplied from the second oxygen supplying means 8 in a state of limiting an oxygen supply amount from the first oxygen supplying means 7 to a small amount until predetermined timing. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a dry distillation gasification furnace that stores waste and burns part of the waste while dry-distilling the remainder of the waste with combustion heat to generate a combustible gas.

  Conventionally, as this type of dry distillation gasifier, ignition means comprising an ignition burner that ignites waste at an ignition port formed at the bottom of the dry distillation gasifier, and oxygen that supplies oxygen from the bottom of the furnace into the dry distillation gasifier What is provided with a supply means is known (for example, refer patent document 1). Moreover, in this thing, the combustion furnace which burns the combustible gas generated in the dry distillation gasification furnace is provided. The combustion furnace includes an auxiliary burner that blows a combustion flame into the furnace.

  By the way, in order to prevent the discharge of dioxins due to incineration of waste, it is effective to retain the waste at a temperature of 800 ° C. or higher for 2 seconds or more to completely thermally decompose the generated dioxins. ing. Therefore, when the combustible gas generated by the ignition of the waste is burned in the combustion furnace while burning the auxiliary burner, and the temperature in the combustion furnace can be maintained at 800 ° C. or higher by burning only the combustible gas. The combustion of the auxiliary burner is stopped.

  Here, in order to shorten the combustion time of the auxiliary burner and reduce the fuel consumption, it is necessary to promote the generation of a fire bed after ignition of the waste and to increase the generation amount of the combustible gas at an early stage. In addition, although the waste is finally ashed, it is necessary to promote the generation of a firebed in order to shorten the total operation time from ignition to completion of ashing.

  However, if the waste is heavy, such as rubber scrap scum dry matter or automobile shredder dust, the waste is crushed by its own weight at the bottom of the dry distillation gasification furnace, making it difficult for the fire to move, It may take time to generate In this case, the amount of oxygen supplied from the bottom of the dry distillation gasification furnace by the oxygen supply means is increased for a while after the waste is ignited and the operation of the ignition means is stopped, thereby promoting the formation of the fire bed. It is possible to do.

However, this causes the following problems. That is, the ignition means ignites the waste that exists in the vicinity of the igniter, and the oxygen supplied from the bottom part of the furnace away from the igniter is transferred to the waste that exists in this part. Becomes surplus oxygen which does not contribute to combustion. And surplus oxygen mixes with combustible gas, and it becomes easy to cause abnormal combustion in a dry distillation gasification furnace.
Japanese Patent No. 2927689

  This invention makes it the subject to provide a dry distillation gasification furnace so that generation | occurrence | production of a fire bed can be accelerated | stimulated without producing the abnormal combustion in a furnace in view of the above point.

  In order to solve the above problems, the present invention is a dry distillation gasification furnace that contains waste and burns part of the waste while dry distillation of the remainder of the waste by combustion heat to generate a combustible gas. In the apparatus comprising ignition means for igniting waste at an ignition port formed at the bottom of the dry distillation gasification furnace, and first oxygen supply means for supplying oxygen from the bottom of the furnace into the dry distillation gasification furnace, The gasification furnace is provided with a second oxygen supply means for supplying oxygen from at least one of the ignition port and a portion adjacent to the ignition port, and the operation of the ignition device is stopped by igniting the waste and during the operation of the ignition device. After that, oxygen is supplied from the second oxygen supply means in a state where the oxygen supply amount from the first oxygen supply means is limited to a predetermined small amount until a predetermined time.

  According to the present invention, oxygen is intensively supplied from the second oxygen supply means to the ignited waste existing in the vicinity of the ignition port. Therefore, even if the amount of oxygen supplied from the first oxygen supply means is limited to a small amount, the oxygen supplied from the second oxygen supply means can quickly change the waste near the ignition port to the waste existing in the interior thereof. Fire is generated and the formation of the fire bed is promoted. Further, since the oxygen supplied from the second oxygen supply means is consumed by the combustion of the waste, excess oxygen and the oxygen supply amount from the first oxygen supply means are limited to a small amount. Abnormal combustion in the dry distillation gasification furnace due to mixing with combustible gas can be prevented.

  However, if the second oxygen supply means is continuously operated, the waste is transferred to the upper layer waste in the dry distillation gasification furnace, and the dry distillation of the middle and upper layer waste is inhibited. Therefore, the operation of the second oxygen supply unit is stopped at a predetermined time after the operation of the ignition unit is stopped. The predetermined time can be set when a predetermined time has elapsed since the operation of the ignition means is stopped. However, a temperature sensor for detecting the temperature in the furnace above the ignition port is provided, and the temperature detected by the temperature sensor is It is desirable to set the time when the temperature rises to a predetermined temperature as the predetermined time. According to this, the 2nd oxygen supply means can be operated to the maximum in the range which does not produce the fire transfer to the middle and upper layer waste, and the generation of the fire bed can be promoted.

  In addition, the oxygen concentration in the gas generated in the dry distillation gasification furnace gradually decreases as the fire bed grows, with an increase in oxygen consumption due to combustion of waste and an increase in combustible gas due to dry distillation. Accordingly, an oxygen concentration sensor for detecting the oxygen concentration in the gas generated in the dry distillation gasification furnace is provided, and the oxygen supply from the second oxygen supply means is stopped when the detected concentration of the oxygen concentration sensor decreases to a predetermined concentration. You may do it.

  Referring to FIG. 1, reference numeral 1 denotes a dry distillation gasification furnace according to an embodiment of the present invention. The dry distillation gasification furnace 1 stores waste such as scum dry matter of rubber scraps and automobile shredder dust, and combusts a part of the waste while dry distillation of the remainder of the waste by combustion heat to generate a combustible gas. It is something to be made. The dry distillation gasification furnace 1 and the combustion furnace 2 for burning the combustible gas generated in the dry distillation gasification furnace 1 constitute a dry distillation gasification incinerator.

  An inlet 3 having an openable / closable door 3 a is formed on the upper surface portion of the dry distillation gasifier 1, and waste is introduced into the dry distillation gasifier 1 from the inlet 3. A water jacket 4 as a cooling structure is formed on the peripheral wall portion of the dry distillation gasification furnace 1. Further, the dry distillation gasification furnace 1 includes an ignition burner 6 as an ignition means facing an ignition port 5 formed in a lower portion of the peripheral wall portion, and a first oxygen supply means for supplying oxygen from the furnace bottom into the dry distillation gasification furnace 1. 7 and a second oxygen supply means 8 for supplying oxygen into the dry distillation gasification furnace 1 from the igniter 5 and a portion adjacent thereto. A shutter 5 b that is opened and closed by an actuator 5 a is provided at the outer end of the ignition port 5. The ignition burner 6 is ignited with the shutter 5b opened, and the combustion flame of the burner 6 is blown into the lower part of the dry distillation gasification furnace 1 through the ignition port 5 to ignite the waste.

The dry distillation gasification furnace 1 includes, as constituent elements of the first oxygen supply means 7, an empty space 9 provided below the bottom of the furnace bottom of the dry distillation gasification furnace 1, and a plurality of air supply holes formed over the entire furnace bottom. 10. Further, carbonization gasification furnace 1, as a component of the second oxygen supply means 8, an air supply nozzle 11 ₁ inserted into the ignition opening 5, the peripheral wall portion adjacent to the ignition port 5 as shown in FIG. 2 and a supply nozzle 11 ₂ inserted through the portion. Then, oxygen (air) from the blower 12 is sent to the empty chamber 9 through the adjustment valve 13, oxygen is supplied from the empty chamber 9 into the dry distillation gasification furnace 1 through the air supply holes 10, and from the blower 12. air supply nozzles ₁₁ 1 oxygen via an on-off valve 14, and 11 ₂ in the feed, the oxygen carbonization gasification furnace 1 from the portion adjacent to the ignition port 5 and the ignition port 5 by the air supply nozzle ₁₁ 1, 11 ₂ I am trying to supply it.

  A gas outlet 15 is formed in the upper part of the peripheral wall of the dry distillation gasifier 1. A combustible gas generated by dry distillation of waste in the dry distillation gasification furnace 1 is introduced into the combustion furnace 2 through a gas pipe 16 connected to a gas outlet 15. Oxygen is supplied to the combustion furnace 2 from the blower 12 through the adjustment valve 17. The combustible gas and oxygen from the dry distillation gasification furnace 1 are mixed in the combustion furnace 2 and burned.

  Further, the combustion furnace 2 includes an auxiliary combustion burner 18 that blows a combustion flame into the combustion furnace 2. And the warm-up operation which raises the temperature in the combustion furnace 2 to 800 degreeC or more which can thermally decompose dioxins by combustion of the auxiliary burner 18 is performed, and after the warm-up operation, the dry distillation gasification furnace 1 is burned by the combustion of the ignition burner 6. The combustible gas generated after the ignition of the waste is combusted in the combustion furnace 2 while the auxiliary burner 18 is combusted, and the temperature in the combustion furnace 2 is 800 ° C. or higher by the combustion of only the combustible gas. When the auxiliary combustion burner 18 can be maintained, the combustion of the auxiliary burner 18 is stopped.

  Here, in order to shorten the combustion time of the auxiliary combustion burner 18 and reduce the fuel consumption, the generation of the fire bed is promoted after ignition of the waste in the dry distillation gasification furnace 1, and the generation amount of the combustible gas is reduced. It is necessary to increase it early. In order to shorten the total operation time from the ignition of the waste to the completion of ashing, it is necessary to promote the generation of the fire bed. However, if the waste has a large specific gravity such as scum-dried rubber scrap or automobile shredder dust, the waste is crushed by its own weight in the lower part of the dry distillation gasification furnace 1, making it difficult for the fire to move. Floor generation can take time.

  In this case, it is conceivable to increase the amount of oxygen supplied from the first oxygen supply means 7 to promote the formation of the fire bed. However, the oxygen supplied from the furnace bottom portion away from the igniter 5 becomes surplus oxygen that does not contribute to combustion until it is transferred to the waste in this portion. Therefore, if the amount of oxygen supplied from the first oxygen supply means 7 is increased, the amount of surplus oxygen increases, and this surplus oxygen is mixed with combustible gas, causing abnormal combustion in the dry distillation gasification furnace 1. It becomes easy to do.

  Thus, in the present embodiment, during the combustion of the ignition burner 6 and after the waste is ignited and the combustion of the ignition burner 6 is stopped, the oxygen supply amount from the first oxygen supply means 7 is set to a predetermined value. Oxygen is supplied from the second oxygen supply means 8 in a state limited to a small amount. According to this, oxygen is intensively supplied from the second oxygen supply means 8 to the ignited waste existing in the vicinity of the igniter 5, and it is transferred to the waste existing inside from this waste at an early stage. Thus, the generation of a firebed is promoted. Further, since the oxygen supplied from the second oxygen supply means 8 is consumed by the combustion of the waste, the surplus is coupled with limiting the amount of oxygen supply from the first oxygen supply means 7 to a small amount. Abnormal combustion in the dry distillation gasification furnace 1 due to mixing of oxygen and combustible gas can be prevented.

  However, if the second oxygen supply means 8 is continuously operated, the waste is transferred to the upper-layer waste in the dry distillation gasification furnace 1, and the dry distillation of the middle- and upper-layer waste is inhibited. Therefore, in the present embodiment, a temperature sensor 19 is provided to detect the temperature of the in-furnace portion located a predetermined distance (for example, 300 mm) above the ignition port 5, and the temperature detected by the temperature sensor 19 has increased to the predetermined temperature. Oxygen supply from the second oxygen supply means 8 is sometimes stopped. The details will be described below with reference to FIG.

At the start of combustion of the ignition burner 6, the adjustment valve 13 is opened to a small opening (for example, an opening of 20% of the fully opened opening), a small amount of oxygen is supplied from the first oxygen supply means 7, and the on-off valve 14 is opened to supply oxygen also from the second oxygen supply means 8 (supply nozzles 11 ₁ and 11 ₂ ). Note that the oxygen supply amount from the first oxygen supply means 7 is set to the minimum necessary amount so as not to cause abnormal combustion of the combustible gas due to surplus oxygen supplied to the portion that has not transferred to the fire. . When the temperature detected by the temperature sensor 19 rises to a predetermined ignition discrimination temperature Ta (for example, 70 ° C.), it is determined that the waste has been ignited, and the combustion of the ignition burner 6 is stopped. On the other hand, after the combustion of the ignition burner 6 is stopped, the oxygen supply from the first oxygen supply means 7 is limited to a small amount, and the oxygen supply from the second oxygen supply means 8 is continued to generate a firebed. Facilitate. Since the temperature sensor 19 penetrates the water jacket 4, the temperature detected by the temperature sensor 19 is lower than the actual temperature.

  Next, when the temperature detected by the temperature sensor 19 rises to a predetermined limit temperature Tb (for example, 130 ° C.) set as high as possible within a range that does not cause fire transfer to waste in the upper layer, The valve 14 is closed and the oxygen supply from the second oxygen supply means 8 is stopped. Thereby, it is prevented that it is transferred to the waste in the middle and upper layers. When the supply of oxygen from the second oxygen supply means 8 is stopped, the power of fire near the blow-in port 5 is attenuated, and the temperature detected by the temperature sensor 19 is lowered.

  Thereafter, oxygen is supplied into the dry distillation gasifier 1 only from the first oxygen supply means 7. Although not shown, the opening degree of the regulating valve 13 is gradually increased step by step while limiting the oxygen supply amount to a level necessary for continuous partial combustion of the waste in the lower layer. When the formation of the fire bed is completed, the combustion heat activates the carbonization of the waste in the middle and upper layers, and the amount of combustible gas generated by the carbonization increases. As a result, the combustible gas is stably combusted at a temperature of 800 ° C. or higher in the combustion furnace 2, and the combustion of the auxiliary burner 18 is stopped.

  In the present embodiment, the generation of the fire bed is promoted by the oxygen supply from the second oxygen supply means 8 as described above, so that the amount of combustible gas generated increases early. Therefore, the combustion time of the auxiliary burner 18 is shortened, and the fuel consumption is reduced.

  By the way, the oxygen concentration in the gas generated in the dry distillation gasification furnace 1 gradually decreases as the fire bed grows, with an increase in oxygen consumption due to combustion of waste and an increase in combustible gas due to dry distillation. Accordingly, an oxygen concentration sensor for detecting the oxygen concentration in the gas generated in the dry distillation gasification furnace 1 is provided in the upper part of the dry distillation gasification furnace 1 or in the gas pipe 16, and the oxygen concentration detected by this oxygen concentration sensor is a predetermined concentration ( For example, the supply of oxygen from the second oxygen supply means 8 may be stopped when the value decreases to 17%.

  It is also possible to stop the oxygen supply from the second oxygen supply means 8 when a predetermined time has elapsed since the combustion stop time of the ignition burner 6. However, if the timing for stopping the supply of oxygen from the second oxygen supply means 8 is determined based on the detected temperature of the temperature sensor 20 or the detected concentration of the oxygen concentration sensor, the middle or upper layer is transferred to waste. Advantageously, the second oxygen supply means 8 can be operated to the maximum extent that it does not occur.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to this. For example, in the above embodiment, the second oxygen supply means 8 is configured to supply oxygen into the dry distillation gasification furnace 1 from the ignition port 5 and a portion adjacent to the ignition port 5. The supply means 8 may supply oxygen only from the ignition port 5 or only from a portion adjacent to the ignition port 5.

  In addition, an adjustment valve is provided in place of the on-off valve 14 of the above embodiment, and when the temperature detected by the temperature sensor 20 rises to some extent, the opening of the adjustment valve is gradually decreased from the fully open position. You may make it close.

  In the above embodiment, the ignition burner 6 is used as the ignition means. However, an electric heater gun or an electric plasma gun may be used, and further, manual ignition means such as a lighter may be used.

Explanatory drawing which shows the structure of the dry distillation gasification incinerator which comprises the dry distillation gasification furnace of embodiment of this invention. FIG. 2 is an enlarged cut plan view of a main part cut along a line II-II in FIG. 1. The detected temperature of the temperature sensor provided in the dry distillation gasification furnace of the embodiment, the opening of the regulating valve for the first oxygen supply means, the opening and closing of the on-off valve for the second oxygen supply means, and the on / off of the ignition burner, The graph which shows the relationship.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Dry distillation gasification furnace, 5 ... Ignition opening, 6 ... Ignition burner (ignition means), 7 ... 1st oxygen supply means, 8 ... 2nd oxygen supply means, 19 ... Temperature sensor.

Claims (3)

It is a dry distillation gasification furnace that stores waste and burns part of the waste and dry distillation of the remainder of the waste by combustion heat to generate a combustible gas, which is formed at the bottom of the dry distillation gasification furnace In what comprises an igniting means for igniting waste at an igniter, and a first oxygen supply means for supplying oxygen from the furnace bottom into the dry distillation gasification furnace,
The dry distillation gasification furnace includes a second oxygen supply means for supplying oxygen from at least one of an ignition port and a portion adjacent to the ignition port, and ignites waste during operation of the ignition device and operates the ignition device. A dry distillation gasification furnace characterized in that oxygen is supplied from the second oxygen supply means in a state where the oxygen supply amount from the first oxygen supply means is limited to a predetermined small amount until a predetermined time after the stop.   2. The dry distillation gasification according to claim 1, further comprising: a temperature sensor that detects a temperature inside the furnace above the ignition port, wherein the predetermined time is when a temperature detected by the temperature sensor rises to a predetermined temperature. Furnace.   2. An oxygen concentration sensor for detecting an oxygen concentration in a gas generated in the dry distillation gasification furnace, wherein the predetermined time is when the detected concentration of the oxygen concentration sensor is lowered to a predetermined concentration. The dry distillation gasifier described.

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