JP4180444B2 - Explosion-proof method of waste crusher using nitrogen gas - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a crusher of a waste treatment facility that crushes municipal waste and industrial waste, and can improve the explosion-proof performance of the crusher more economically, easily and reliably using nitrogen gas. The present invention relates to an explosion-proof method for a crusher using nitrogen gas.
[0002]
[Prior art]
When disposing of municipal waste and industrial waste by incineration, melting, gasification, etc., first crush large-sized waste, non-combustible waste, etc. (hereinafter referred to as waste) into a desired size in a crushing treatment facility, After sorting into valuables, incombustibles, combustibles, etc., appropriate processing corresponding to each sort is performed.
[0003]
By the way, many waste containers such as LP gas cylinders, spray cans, organic solvent containers, gasoline containers, kerosene containers, etc. (hereinafter referred to as dangerous substances) are mixed in the waste. In principle, these dangerous materials are separated and removed at the waste collection stage.
[0004]
However, in reality, there are many hazardous materials mixed in the waste that is brought into the waste treatment facility. Therefore, in the waste treatment facility, before putting the waste into the crusher, In addition, dangerous materials and the like are selected and removed mechanically or visually by an operator.
[0005]
In addition, each crusher is equipped with a so-called explosion-proof device in case a dangerous material is thrown into the crusher due to an error, thereby preventing a fire or explosion accident in the crusher. ing.
[0006]
In addition, for the explosion-proofing of the crusher, a dilution air suction method and a water vapor suction method are generally used. In the former dilution air suction method, a large amount of air is blown into the crusher. The flammable gas concentration in the atmosphere inside the crusher is diluted to a concentration below the lower limit of the explosion to prevent explosion.
Further, in the latter water vapor suction method, the explosion is suppressed by sucking water vapor into the crusher and maintaining the combustible gas concentration in the crusher atmosphere at a concentration outside the explosion limit.
[0007]
[Patent Document 1]
Japanese Patent No. 1612826 [Patent Document 2]
Japanese Patent No. 1181078
Both of the above explosion-proof methods have many achievements in practical use and have been proved to have excellent explosion-proof performance.
However, there are still many problems to be solved in both explosion-proof systems. For example, in the former dilution air suction method, a large amount of air is blown into the crusher, so there is little risk of flammable gas remaining inside the crusher, but the amount of floating dust inside the crusher will increase. As a result, there is a problem that the dust collector for processing the exhaust air from the crusher is increased in size.
[0009]
In addition, at the stage where the combustible gas in the atmosphere inside the crusher is diluted by blowing in air, it partially passes through the explosive concentration region of the combustible gas for a short time, so there is a possibility of explosion. There is a problem that the reliability is low.
[0010]
Furthermore, the construction of the explosion-proof equipment requires an air suction blower, an exhaust fan, a dust collector, a silencer, an air duct, and the like, which makes it difficult to downsize the equipment.
[0011]
On the other hand, the same applies to the latter water vapor suction method, and the construction of the explosion-proof equipment requires a steam generating boiler, boiler fuel supply device, water supply equipment, drainage / exhaust steam treatment equipment, dust collector, etc. There is a difficulty that it is difficult to reduce the size of the equipment.
[0012]
In addition, there is a problem that a warm-up time is required at the initial stage of operation of the explosion-proof equipment, and that the combustion consumption in the steam generating boiler becomes large, so that the running cost cannot be reduced.
[0013]
Furthermore, because the waste is crushed in the steam atmosphere, the condensate of the input steam generated in the crusher corrodes the inside of the crusher and various equipment connected to the crusher. There is.
[0014]
[Problems to be solved by the invention]
The present invention has a problem as described above in the conventional explosion-proof equipment of this kind of waste treatment crusher, that is, it is difficult to downsize the equipment in the air suction type explosion-proof equipment, and the size of the dust collector is increased. In addition, the problem of low reliability of explosion-proof performance, etc., and the difficulty of downsizing the equipment with the water vapor suction-type explosion-proof equipment, and the problem of internal corrosion of equipment due to condensate are likely to be solved. By using nitrogen gas from the nitrogen generator attached to the waste treatment facility, the explosion-proof property of the crusher can be secured economically, easily and reliably, and the equipment can be greatly downsized. The present invention provides an explosion-proof method for a waste disposal crusher using nitrogen gas.
[0015]
[Means for interpreting problems]
The use of nitrogen gas for preventing explosions has been widely put into practical use by, for example, a method of filling N ₂ gas in the upper space of a dangerous goods tank.
However, in the field of waste processing crushers and the like, since the amount of leakage of N ₂ gas has been large in the past, running costs have soared and it is impossible to use N ₂ gas for actual use. It was thought.
[0016]
However, as mentioned above, the corrosion problem is unavoidable with the steam type explosion proof, and the safety problem with the air suction type explosion proof, it is said that the development of an alternative explosion proof method has become an urgent task. There is reality.
Therefore, the inventors of the present application have conceived the use of nitrogen gas, which has been considered impossible in terms of running cost, and whether or not the use of nitrogen is actually impossible in terms of running cost. In addition, various tests related to explosion-proof performance, nitrogen consumption, measures to reduce consumption, etc. were conducted using an actual plant for crushers.
[0017]
The invention of the present application was created based on the above test results, and the invention of claim 1 is a waste having at least two sealing devices through which the waste can pass with a gap at the tip . supplies upwardly to the waste shredder body through feed conveyors, the desired crushed waste into dimensions, spaced proximal end, the crushed waste seal both groups least passable a was set to be carried out to the outside by the discharge conveyor having a device waste crusher, provided crusher body Nde write blowing nitrogen gas through the oxygen concentration controller from the nitrogen gas supply device into the shredder body The oxygen concentration in the crusher body is detected by the oxygen concentration detector, and the amount of nitrogen gas supplied to the crusher body through the control device and the oxygen concentration controller is adjusted by the detection signal of the oxygen concentration detector. ,Crushing machine Both Holding the oxygen concentration in the body 8 to 11% of the density value, an exhaust hood portion between the seal device of the waste feed conveyor, an exhaust hood portion between the seal device of the output conveyor, and each exhaust Each of the hoods is provided with an oxygen concentration detector, and further, an oxygen concentration controller is provided on the suction side of the ventilation fan that discharges the gas in each exhaust hood, and the exhaust hood detected by the oxygen concentration detector The nitrogen gas concentration of the exhaust hood exhaust gas is obtained from the oxygen concentration, and when the nitrogen gas concentration exceeds a predetermined value, the discharge amount of the exhaust gas from the ventilation exhaust fan is reduced via the control device and the oxygen concentration controller. In addition, the upper part and the lower part of the waste crusher main body are communicated in a bypass manner with a nitrogen gas circulation line, and a circulation fan is provided in the circulation line, and the inside of the crusher main body is provided by the circulation fan. It is an basic configuration of the invention that so as to produce force the circulating gas stream toward upward than downward.
[0020]
The invention of claim 2 is the waste to the waste crusher when the oxygen concentration detection values of the oxygen concentration detectors 15a, 15b of the waste crusher main body 1a exceed the set value in the invention of claim 1. The supply of is stopped.
[0021]
The invention of claim 3 is the invention of claim 1, wherein the combustible gas detector 17 is provided in the waste crusher main body 1a, and the detection value by the combustible gas detector 17 exceeds the set value. The supply of waste to the waste crusher 1 is stopped.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an overall system diagram of a waste treatment crusher A embodying the present invention. In FIG. 1, 1 is a rotary crusher, 1a is a crusher body, 2 is a waste supply conveyor, 2a Is a supply conveyor drive motor, 3 is a discharge conveyor, 4 is a carry-out conveyor, 5 is a nitrogen gas supply device, 6 is a control device, 7, 9 and 10 are sealing devices, 12 is an induction fan, 13 is a circulating fan, 14a -14d is a nitrogen gas suction nozzle, 15a to 15d are oxygen concentration detectors, 16a and 16b are oxygen concentration controllers, 16c and d are oxygen concentration controllers, 17 is a combustible gas detector, N is a nitrogen gas supply line, O is a detection signal line, C is a control signal line, L is a nitrogen gas circulation line, and V is an exhaust line.
[0023]
The rotary crusher 1 is a so-called hammer type or rotary blade type crusher, crushing the waste carried into the main body through the upper opening of the crusher main body 1a, and crushing pieces having a size of a predetermined size or less. Form.
Further, exhaust hood portions 2b and 4b are provided at the distal end portion of the waste supply conveyor 2 and the proximal end portion of the carry-out conveyor 4, respectively, and a mixture of air and nitrogen leaked from the crusher main body 1a. Gas (exhaust gas G) is collected here and discharged to the outside. Further, wastes made of so-called rubber plates or thin metal plates are disposed on the downstream side of the exhaust hood portion 2b and the upstream side of the exhaust hood portion 4b at the distal end portion of the waste supply conveyor 2 and the proximal end portion of the discharge conveyor 4. Noren-like sealing devices 7, 9, and 10 through which air can pass are provided at regular intervals, so that the internal space of the crusher main body 1a is kept as close as possible to the outside air. It is configured.
[0024]
The nitrogen gas supply device 5 supplies a predetermined amount of nitrogen gas into the crusher body 1a, and may be a liquefied nitrogen gas supply device or an air separation type nitrogen gas generation device. In this embodiment, a nitrogen gas generator having a structure in which N ₂ is obtained by adsorbing and separating O ₂ in the air with an adsorbent is used.
[0025]
The nitrogen gas suction nozzles 14a to 14d are appropriately distributed and installed in the upper part and the lower part of the crusher body 1a. In this embodiment, each nitrogen gas suction nozzle is passed through two nitrogen gas supply lines N. Nitrogen gas is supplied to 14a-14d.
[0026]
Each nitrogen gas supply line N is provided with oxygen concentration controllers 16a and 16b. By adjusting the opening of the control valve by a control signal from the control device 6 as will be described later, nitrogen gas supply is performed. The amount, that is, the O ₂ concentration in the crusher body 1a is adjusted.
[0027]
The oxygen concentration detectors 15a to 15d are each one above and below the crusher body 1a, and one each near the exhaust hood 2b of the waste supply conveyor 2 and one near the exhaust hood 4b of the carry-out conveyor 4. The former two oxygen concentration detectors 15a and 15b literally detect the O ₂ concentration in the crusher main body 1a, respectively.
[0028]
On the other hand, the latter two oxygen concentration detectors 15c and 15d obtain the N ₂ concentration from the O ₂ concentration in each exhaust hood portion 2b and 4b, and are attracted when the N ₂ concentration in this portion is high. This is for reducing the amount of nitrogen gas discharged (loss amount) by controlling the operation of the exhaust fan 12.
[0029]
The induced exhaust fan 12 discharges exhaust gas G composed of air, nitrogen, other dust, etc. from the crusher main body 1a to the outside (for example, exhaust gas treatment device), and the discharge amount is oxygen concentration. It is adjusted by the control valve of the controller 16c · d.
[0030]
The circulation blower 13 sends the atmosphere below the inside of the crusher main body 1a upward, and forcibly circulates the atmosphere through the circulation line L. The N ₂ circulation device comprising the circulation blower 13 and the circulation line L is provided. By providing this, the N ₂ concentration inside the crusher main body 1a is maintained uniformly.
[0031]
The control device 6 controls the entire crusher prevention amount equipment according to the present invention. O ₂ concentration detection signals are input from the oxygen concentration detectors 15a to 15d, and each oxygen concentration controller. Control signals are transmitted to 16a, 16b, the oxygen concentration controller 16c, d, the induction fan 12, the circulation fan 13, the supply conveyor drive motor 2a, and the nitrogen gas supply device 5, respectively.
Similarly, a detection signal is input from the combustible gas concentration detector 17 to the control device 6.
[0032]
Next, an explosion-proof method for the waste crusher according to the present invention will be described with reference to FIG.
The waste carried in by the waste supply conveyor 2 passes through the sealing device 7 and is carried from above the crusher main body 1a and crushed to an appropriate size by a rotating hammer (or a rotary blade, not shown). After that, it is discharged onto the discharge conveyor 3 from below, taken over by the discharge conveyor 4, and carried out to the outside through the sealing devices 9 and 10, where non-combustible materials and valuables (metals) are appropriately sorted and collected.
[0033]
On the other hand, a predetermined amount of nitrogen gas is continuously or intermittently supplied from the nitrogen gas supply device 5 through the nitrogen gas suction nozzles 14a to 14d into the crusher body 1a, whereby the oxygen concentration in the crusher body 1a. Is kept outside the explosion limit (oxygen concentration 8-11%).
[0034]
Further, the gas (G) inside the crusher main body 1a is circulated from the lower side to the upper side to some extent by the rotation of the crusher rotary blade or the like. The flow of gas G toward the surface is formed, so that the nitrogen gas concentration in each part in the main body 1a is kept at a very uniform concentration.
[0035]
Further, the mixed gas (exhaust gas) G of air and nitrogen flowing into the exhaust hood portions 2b and 4b through the seal device 8 and the seal device 7 and the seal devices 9 and 10 and the seal device 10 is discharged to the outside by the induced exhaust fan 12. Going to be.
[0036]
Wherein the oxygen concentration in the shredder body 1a, each oxygen concentration sensor 15a, through the control device 6 by the detection signal of 15b, the oxygen concentration controller 16a, N ₂ gas by adjusting the control valve opening 16b By adjusting the supply amount, the O ₂ concentration value is adjusted to about 8 to 11%.
[0037]
Further, the oxygen concentration in each of the seal portions 2b and 4b is detected by the oxygen concentration detectors 15c and 15d, and the oxygen concentration in the portion has decreased from the set value (that is, the nitrogen concentration in the portion has increased). In that case, the control valve of the induced exhaust fan 12 and the oxygen concentration controller 16c · d is adjusted to reduce the emission amount of the exhaust gas G. This prevents nitrogen gas from leaking to the upstream side of the exhaust hood portion 2b and the downstream side of the exhaust hood portion 4b, thereby reducing the amount of nitrogen gas loss.
If the detected values of the oxygen concentration detectors 15a and 15b and the combustible gas concentration detector 17 exceed the set values, the supply of waste to the crusher main body 1a is automatically stopped.
[0038]
【The invention's effect】
In the present invention, since nitrogen gas is supplied into the main body of the waste treatment crusher and the oxygen concentration inside the main body is maintained at 8 to 11%, it is compared with the case of the conventional air suction method. This greatly improves the safety of the crusher. Further, there is no problem of corrosion as in the case of water vapor suction, and no problem of the ejection of steam from the exhaust hood portions 2b, 4b or the like.
[0039]
Furthermore, in the present invention, the internal gas of the crusher body 1a is forcibly circulated by the circulation device comprising the circulation blower 13 and the nitrogen gas circulation line L, so that the oxygen concentration in the crusher body 1a is reduced. It is made uniform and the explosion-proof performance of the crusher is greatly improved.
In addition, since the amount of gas G discharged by the induced exhaust fan 12 is controlled according to the nitrogen concentration in each exhaust hood 2b, 4b, the loss of nitrogen gas discharged to the outside is greatly reduced. It will be.
As described above, the present invention has excellent practical utility.
[Brief description of the drawings]
FIG. 1 is an overall system diagram of a waste disposal crusher embodying the present invention.
[Explanation of symbols]
A Waste disposal crusher G Exhaust gas (air + nitrogen, etc.)
DESCRIPTION OF SYMBOLS 1 Rotary crusher 1a Crusher main body 2 Waste supply conveyor 2a Supply conveyor drive motor 2b Exhaust hood part 3 Discharge conveyor 4 Carry-out conveyor 4b Exhaust hood part 5 Nitrogen gas supply apparatus 6 Control apparatus 7 Seal apparatus 9 Seal apparatus 10 Seal Device 12 Induced exhaust fan 13 Circulating fan 14a-14d Nitrogen gas suction nozzles 15a-15d Oxygen concentration detectors 16a-16b Oxygen concentration controller 16c, d Oxygen concentration controller 17 Combustible gas detector N Nitrogen gas supply line O Detection signal Line C Control signal line L Nitrogen gas circulation line V Exhaust line

Claims (3)

The waste is supplied to the upper part of the crusher main body through a waste supply conveyor having at least two sealing devices through which the waste can pass with a gap at the tip, and the waste crushed to a desired size , spaced proximal end, a waste crusher which is adapted to discharge to the outside by the discharge conveyor which crushed waste with a seal device both groups least passable, crushed Nde write blowing nitrogen gas through the oxygen concentration controller from the nitrogen gas supply device into the machine body to detect the oxygen concentration in the crusher main body by the oxygen concentration sensor provided in the crusher body, the detection signal of the oxygen concentration detector both the controller and through the oxygen concentration controller to adjust the amount of nitrogen gas supplied to the shredder body, when holding the oxygen concentration of the crusher body 8-11% of the density values by the waste feed Combe An exhaust hood portion is provided between the sealing devices of the discharge conveyor, an exhaust hood portion is provided between the sealing devices of the carry-out conveyor, and an oxygen concentration detector is provided in each exhaust hood portion. Further, the gas in each exhaust hood portion is discharged. An oxygen concentration controller is provided on the suction side of the exhaust fan, and the nitrogen gas concentration of the exhaust hood exhaust gas is obtained from the oxygen concentration of the exhaust hood detected by the oxygen concentration detector, and the nitrogen gas concentration is a predetermined value. If exceeded, the amount of exhaust gas discharged from the permeation exhaust fan is reduced via the controller and oxygen concentration controller, and the upper and lower parts of the waste crusher body are bypassed by the nitrogen gas circulation line. The nitrogen is characterized in that a circulation blower is interposed in the circulation line and a circulation gas flow is generated in the inside of the crusher main body from the lower side to the upper side by the circulation blower. Proof爆方method of waste disposal for the crushing machine using the scan. The nitrogen gas according to claim 1, wherein the supply of waste to the waste crusher is stopped when the oxygen concentration detection value of the oxygen concentration detector of the waste crusher body exceeds a set value . Explosion-proof method for waste processing crusher. A combustible gas detector is provided in the waste crusher body, and the supply of waste to the waste crusher is stopped when a detection value by the combustible gas detector exceeds a set value. Explosion-proof method for waste treatment crusher using nitrogen gas described in 1.

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