JP2010024665A - Asphalt mixture manufacturing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an asphalt mixture manufacturing apparatus, reducing radiation of heat from a dust collector such as a bag filter to prevent dew condensation. <P>SOLUTION: This asphalt mixture manufacturing apparatus includes: a plurality of bag filters 4a, 4b arranged in parallel to an R dryer 1 and a V dryer 2; and shut off dampers 6a-1, 6a-2, 6b-1, 6b-2 provided in the bag filters 4a, 4b, respectively, to shut off or pass inflow of exhaust gas of the R dryer 1 and the V dryer 2, wherein according to the required processing amount of exhaust gas of the R dryer 1 and the V dryer 2, only the shut off dampers 6a-1, 6a-2, 6b-1, 6b-2 of the required bag filters 4a, 4b are opened, and the shut off dampers 6a-1, 6a-2, 6b-1, 6b-2 of unnecessary bag filters 4a, 4b are closed so that the respective bag filters 4a, 4b can be prevented from an excess of capability. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an asphalt mixture manufacturing apparatus that manufactures asphalt mixture by mixing asphalt and aggregate.

  FIG. 3 is a schematic configuration diagram of a conventional asphalt composite material manufacturing apparatus. As shown in FIG. 3, a conventional asphalt composite material manufacturing apparatus includes a virgin dryer 50, a cyclone dust collector 51 as a primary dust collector, a bag filter 52 as a secondary dust collector, an air volume adjusting damper 53, an exhaust fan 54 and A chimney 55 is provided, and the opening degree of the air volume adjusting damper 53 is adjusted according to the internal pressure of the virgin dryer 50, and the internal pressure of the virgin dryer 50 is controlled to be a set value.

  As shown in FIG. 4, in the recycling plant in which the virgin dryer 50 and the recycling dryer 56 are arranged in parallel, one cyclone dust collector 51, 57 is provided for each dryer 50, 56. The bag filter 52 is an auxiliary dust collector that captures small dust mixed with exhaust gas that cannot be collected by the cyclone dust collectors 51 and 57. Therefore, in this type of recycling plant, both the dryers 50 and 56 are used. One bug filter 52 is shared (for example, refer to Patent Document 1). The maximum exhaust gas processing capacity of the bag filter 52 is designed according to the simultaneous operation of the virgin dryer 50 and the recycle dryer 56.

Japanese Patent Laid-Open No. 2005-248489

  In recent years, asphalt composites have been recycled, and the proportion of recycled materials mixed with 60% or more of recycled materials has been increasing. On the other hand, high-performance paving materials such as drainage asphalt composites that do not contain recycled materials are also gradually increasing. When these asphalt composite materials are produced by an asphalt composite material manufacturing apparatus as shown in FIG. 4, the virgin dryer 50 and the recycle dryer 56 are operated in accordance with the mixing ratio of the recycled material.

  However, when trying to produce a composite material with a recycled material mixing rate of 0 to 60% in the same asphalt composite material manufacturing apparatus in this way, the operating range of the virgin dryer 50 becomes 100% to 40% of the production capacity, and the exhaust gas is exhausted. Similarly, the amount of gas changes to about 100 to 40%. Therefore, when producing a new composite material with a recycled material mixing rate of 0% using this asphalt composite material manufacturing apparatus, only the virgin dryer 50 is operated, and the capacity of the bag filter 52 becomes excessive.

  At this time, the amount of exhaust gas processed by the bag filter 52 is only about 1/2 of that when the virgin dryer 50 and the recycle dryer 56 are operated at the same time, and the new material contains a lot of water vapor, so the bug has an excessive capacity. The filter 52 has a large amount of heat dissipation and is likely to condense. Then, if moisture in the exhaust gas is condensed on the wall surface in the bag filter 52, there arises a problem that the dust in the exhaust gas becomes muddy and closes the bag filter 52.

  Therefore, an object of the present invention is to provide an asphalt mixture manufacturing apparatus capable of reducing heat radiation from a dust collector such as a bag filter and preventing condensation.

  The asphalt composite material manufacturing apparatus of the present invention is provided in each of a plurality of dust collectors arranged in parallel to the dryer and a plurality of dust collectors in order to block or pass the inflow of exhaust gas from the dryer. It has a cutoff damper. According to the asphalt composite material manufacturing apparatus of the present invention, only the necessary dust collector cutoff dampers are opened according to the required exhaust gas processing amount of the dryer, and unnecessary dust collector cutoff dampers are closed, so that each It is possible to prevent the dust collector from having an excessive capacity.

  Here, in the case of a recycling plant that uses recycled material, the asphalt composite material manufacturing apparatus of the present invention is such that the dryer is a virgin dryer and a recycled dryer, and the virgin dryer and the recycled dryer are each provided with a primary dust collector, It is desirable that the plurality of dust collectors are secondary dust collectors. Thus, when operating the virgin dryer and the recycle dryer according to the mixing rate of the recycled material, only the shut-off damper of the secondary dust collector required according to the required processing amount of the exhaust gas of these dryers is opened. By closing the shut-off damper of the unnecessary secondary dust collector, it is possible to prevent each secondary dust collector from having an excessive capacity.

  Further, in the case of an asphalt plant that does not use recycled materials, the asphalt mixture manufacturing apparatus of the present invention includes a plurality of primary dust collectors in which the dryer is a virgin dryer, and the virgin dryer is arranged in parallel downstream. A primary cutoff damper for blocking the flow of exhaust gas from the virgin dryer to a primary dust collector other than the selected primary dust collector among the primary dust collectors. A dust device is desirable. As a result, only the necessary secondary dust collector shut-off dampers are opened according to the required amount of exhaust gas from the virgin dryer, and unnecessary secondary dust collector shut-off dampers are closed. It is possible to prevent the device from being overpowered.

  Further, in the asphalt composite material manufacturing apparatus of the present invention, the dust collector is a bag filter, and further measured by a differential pressure measuring device for measuring a differential pressure before and after the filter medium of the bag filter, and a differential pressure measuring device. It is desirable to have a control device that controls the opening and closing of the shut-off damper provided in each bag filter in accordance with the differential pressure value. As a result, the degree of clogging of the bag filter is determined based on the differential pressure value measured by the differential pressure measuring device, and the opening / closing of the cutoff damper is automatically controlled according to the degree of clogging of the bag filter, and the bag filter to be used is determined. It becomes possible to select automatically.

  Furthermore, in the asphalt composite material manufacturing apparatus of the present invention, a pressure measuring device for measuring the internal pressure of the dryer, an exhaust fan disposed downstream of the dust collector, a load measuring device for measuring the load of the exhaust fan, It is desirable to have a control device that controls the opening and closing of the shut-off damper provided in each of the dust collectors according to the pressure value measured by the pressure measuring device and the load value measured by the load measuring device. Thus, when it is determined that the dust collector cannot be switched from the pressure value measured by the pressure measuring instrument and the load value measured by the load measuring instrument, the dust collector is used without switching. It becomes possible.

(1) By having a plurality of dust collectors arranged in parallel to the dryer, and a shut-off damper provided in each of the plurality of dust collectors in order to block or pass the inflow of exhaust gas from the dryer In addition, it is possible to prevent the capacity of each dust collector from becoming excessive with respect to the required processing amount of the exhaust gas of the dryer, and it is possible to reduce condensation by preventing excessive heat radiation from the dust collector.

(2) In the case of a recycling plant that uses recycled materials, the dryers are virgin dryers and recycling dryers, and the virgin dryers and recycling dryers each have a primary dust collector downstream, and multiple dust collectors are secondary dust collectors. Because it is a device, when operating virgin dryers and recycle dryers in accordance with the mixing rate of recycled materials, only the secondary dust collector cutoff damper required according to the required exhaust gas treatment amount of these dryers Opening and closing the shut-off damper of the unnecessary secondary dust collector can prevent each secondary dust collector from being overpowered, reducing excessive heat radiation from the dust collector and causing condensation. Can be prevented.

(3) In the case of an asphalt plant that does not use recycled materials, the dryer is a virgin dryer, and the virgin dryer is selected from a plurality of primary dust collectors arranged in parallel downstream and the plurality of primary dust collectors. A primary cutoff damper for blocking the flow of exhaust gas from the virgin dryer to the primary dust collector other than the primary dust collector, and the plurality of dust collectors are secondary dust collectors. Open only the necessary secondary dust collector shut-off dampers according to the required exhaust gas treatment volume, and close unnecessary secondary dust collector shut-off dampers. It is possible to prevent the dew condensation by reducing excessive heat radiation from the dust collector.

(4) The dust collector is a bag filter, and further includes a differential pressure measuring device for measuring the differential pressure before and after the filter medium of the bag filter, and a bag filter according to the differential pressure value measured by the differential pressure measuring device. By having a control device for controlling the opening and closing of the shut-off damper provided in each, the opening and closing of the shut-off damper is automatically controlled according to the clogging condition of the bug filter, and the bug filter to be used is automatically selected. It becomes possible. Thereby, while being able to always ensure the optimal filtration area for dust collection, a bag filter can be used, without applying an excessive pressure to a filter medium.

(5) A pressure measuring device for measuring the internal pressure of the dryer, an exhaust fan disposed downstream of the dust collector, a load measuring device for measuring the load of the exhaust fan, and a pressure value measured by the pressure measuring device And a control device that controls the opening and closing of the shut-off damper provided in each of the dust collectors according to the load value measured by the load measuring device, in an optimum state according to the capacity of the dust collector It can be operated and the load on the exhaust fan is also optimized. As a result, it is possible to produce asphalt mixture without using wasted power. In particular, when the dust collector is a bag filter, it can be operated in a state optimal for the filter medium of the bag filter, and the life of the filter medium is extended.

(Embodiment 1)
FIG. 1 is a schematic configuration diagram of an asphalt composite material manufacturing apparatus according to a first embodiment of the present invention.
In FIG. 1, the asphalt composite material manufacturing apparatus according to the first embodiment of the present invention is referred to as a recycle dryer (hereinafter referred to as “R dryer”) that processes waste material (hereinafter referred to as “R material”) on an asphalt paved road. ) 1, virgin dryer (hereinafter referred to as “V dryer”) 2 for processing a new asphalt material (hereinafter referred to as “V material”), and dust generated in the R dryer 1 and V dryer 2. Cyclone dust collectors 3a and 3b as primary dust collectors to be collected, respectively, and air volume adjusting dampers 5a and 5b for adjusting the air volume of the air flow paths 10a and 10b are provided.

  The ventilation paths 10a and 10b arranged on the downstream side of the two dryers 1 and 2 merge with the ventilation path 11 via the air volume adjustment dampers 5a and 5b, respectively. The ventilation path 11 branches into two ventilation paths 12a and 12b, and bag filters 4a and 4b as secondary dust collectors are connected to the downstream of each. Ventilation paths 13 a and 13 b are respectively arranged downstream of the bag filters 4 a and 4 b and merge with the ventilation path 14. In the ventilation paths 12a, 12b, 13a, and 13b, shut-off dampers 6a-1, 6a-2, 6b-1, and 6b-2 that shut off or allow inflow of exhaust gas by opening and closing are disposed. In the ventilation path 14, an air volume adjustment damper 7 for controlling the ventilation volume is disposed. An exhaust fan 8 and a chimney 9 are arranged downstream of the air volume adjusting damper 7.

  Further, the asphalt composite material manufacturing apparatus includes a differential pressure sensor 15a, 15b as a pressure measuring device for individually measuring the internal pressures of the R dryer 1 and the V dryer 2, and before and after the filter media of the bag filters 4a, 4b. Differential pressure measuring devices 16a and 16b that individually measure the differential pressure, load measuring device 17 that measures the load of the exhaust fan 8, these differential pressure sensors 15a and 15b, differential pressure measuring devices 16a and 16b, Control for controlling the air volume adjusting dampers 5a, 5b, 7 and the shut-off dampers 6a-1, 6a-2, 6b-1, 6b-2, etc. in accordance with detection signals from the load measuring device 17 and the differential pressure sensors 15a, 15b. Device 18.

  In the asphalt composite material manufacturing apparatus having the above-described configuration, when the R dryer 1 and the V dryer 2 are started simultaneously, the cutoff damper 6a-1 is used in order to utilize the maximum exhaust gas processing capacity of both the bag filters 4a and 4b. , 6a-2, 6b-1, and 6b-2 are all fully open. However, in practice, the R material 1 that has been heated and dried in advance is stored in a surge bin (not shown) and stored in a surge bin to some extent before the V dryer 2 is operated. In many cases, materials are mixed and shipped.

  Therefore, in the asphalt composite material manufacturing apparatus according to the present embodiment, when only the R dryer 1 is operated, the air volume adjustment damper 5b is fully closed, and the cutoff dampers 6b-1 and 6b-2 before and after the bag filter 4b are provided. Both are fully closed to prevent exhaust gas from passing. Then, the burner 1a of the R dryer 1 is ignited and the operation is started. At this time, both the shut-off dampers 6a-1 and 6a-2 are fully opened, and the exhaust gas of the R dryer 1 passes through the cyclone dust collector 3a, the ventilation paths 10a, 11, 12a, and the shut-off damper 6a-1 to pass through the bug filter 4a. Further, it passes through the shut-off damper 6a-2, the ventilation paths 13a and 14, the air volume adjusting damper 7, the exhaust fan 8 and the chimney 9, and is discharged.

  As described above, when only the R dryer 1 is operated, when a plurality of bag filters 4a and 4b arranged in parallel to the R dryer 1 are used, the capacity of the bag dryer 4 is excessive. Thus, heat dissipation in the bag filter 4a is prevented, and it becomes possible to prevent condensation of moisture in the exhaust gas in the bag filter 4a. This prevents dust in the exhaust gas from becoming muddy and closing the bag filter 4a.

  In addition, when supplying a small amount of aggregate to the V dryer 2 when the temperature is low, the R dryer 1 is not used but only the V dryer 2 is used. The shut-off dampers 6b-1 and 6b-2 before and after the filter 4b are both fully closed to prevent the exhaust gas from passing therethrough. Then, the burner 2a of the V dryer 2 is ignited and the operation is started. At this time, both of the cutoff dampers 6a-1 and 6a-2 are fully open, and the exhaust gas of the V dryer 2 passes through the cyclone dust collector 3b, the ventilation paths 10b, 11, 12a, and the cutoff damper 6a-1 to the bag filter 4a. Further, it passes through the shut-off damper 6a-2, the ventilation paths 13a and 14, the air volume adjusting damper 7, the exhaust fan 8 and the chimney 9, and is discharged.

  As described above, when both the bug filters 4a and 4b are excessively operated when only the V dryer 2 is operated, only one of the bug filters 4a is used as described above. Heat dissipation is prevented, and condensation of moisture in the exhaust gas in the bag filter 4a can be prevented. This prevents dust in the exhaust gas from becoming muddy and closing the bag filter 4a.

  In addition, when the bag filter 4a is preferentially used in this way, the filter medium of the bag filter 4a is clogged before the filter medium of the bag filter 4b. However, in the asphalt composite material manufacturing apparatus in the present embodiment, The differential pressure before and after the filter medium of the bag filter 4a is measured by the differential pressure measuring device 16a, and the control device 18 determines the cutoff dampers 6a-1, 6a-2, according to the differential pressure value measured by the differential pressure measuring device 16a. Controls opening and closing of 6b-1 and 6b-2.

  For example, when the differential pressure value measured by the differential pressure measuring device 16a is equal to or greater than a predetermined value, the control device 18 fully closes the cutoff dampers 6a-1 and 6a-2 before and after the bag filter 4a, Both cutoff dampers 6b-1 and 6b-2 before and after the bag filter 4b are fully opened. Thereby, the exhaust gas of the R dryer 1 or the V dryer 2 passes through the bag filter 4b through the ventilation paths 11 and 12b and the cutoff damper 6b-1, and further, the cutoff damper 6b-2, the ventilation paths 13b and 14 and the air volume adjustment. It passes through the damper 7, the exhaust fan 8 and the chimney 9 and is discharged.

  On the contrary, when the differential pressure value measured by the differential pressure measuring device 16b becomes equal to or greater than a predetermined value, the control device 18 fully closes the cutoff dampers 6b-1 and 6b-2 before and after the bag filter 4b. Both of the cutoff dampers 6a-1 and 6a-2 before and after the bag filter 4a are fully opened. Thereby, the exhaust gas of the R dryer 1 or the V dryer 2 passes through the bag filter 4b through the ventilation paths 11 and 12a and the cutoff damper 6a-1, and further, the cutoff damper 6a-2, the ventilation paths 13a and 14 and the air volume adjustment. It passes through the damper 7, the exhaust fan 8 and the chimney 9 and is discharged.

  As described above, in the asphalt composite material manufacturing apparatus according to the present embodiment, the cutoff dampers 6a-1, 6a-2, 6b-1, and 6b-2 are automatically opened and closed according to the degree of clogging of the bag filters 4a and 4b. Since the bag filters 4a and 4b to be controlled and automatically selected are used, it is possible to always secure the minimum filtration area for collecting dust, and without causing excessive pressure on the filter media of the bag filters 4a and 4b. Filters 4a and 4b can be used. As a result, the load on the exhaust fan 8 is also optimized, so that asphalt mixture can be produced without using wasted power. In addition, the life of the filter media of the bag filters 4a and 4b is extended.

  Further, in the asphalt composite material manufacturing apparatus according to this embodiment, the pressure values of the R dryer 1 and V dryer 2 measured by the differential pressure sensors 15a and 15b and the load of the exhaust fan 8 measured by the load measuring device 17 are used. Depending on the value, the control device 18 controls the opening / closing of the air volume adjusting dampers 5a, 5b and the shutoff dampers 6a-1, 6a-2, 6b-1, 6b-2 of the bag filters 4a, 4b.

  For example, the bag filters 4 a and 4 b can be switched based on the pressure values of the R dryer 1 and V dryer 2 measured by the differential pressure sensors 15 a and 15 b and the load value of the exhaust fan 8 measured by the load measuring device 17. If it is determined that it is not possible to switch the bug filters 4a, 4b, all the cutoff dampers 6a-1, 6a-2, 6b-1, 6b-2 are opened, and both bug filters 4a, 4b are opened. use. Thereby, it can drive | operate in the optimal state for the filter medium of bag filter 4a, 4b, and the load to the exhaust fan 8 is also optimized.

(Embodiment 2)
FIG. 2 is a schematic configuration diagram of the asphalt composite material manufacturing apparatus according to the second embodiment of the present invention. In FIG. 2, the same components as those described with reference to FIG.

  As shown in FIG. 2, the asphalt composite material manufacturing apparatus according to the second embodiment of the present invention is one in which two cyclone dust collectors 3 a and 3 b are arranged in parallel with respect to the V dryer 2. The ventilation passage 19 connecting the V dryer 2 and the cyclone dust collector 3a is provided with a shut-off damper 20a for shutting off or passing exhaust gas by opening and closing. Similarly, a shutoff damper 20b for shutting off or passing exhaust gas by opening and closing is disposed in the ventilation path 10a downstream of the cyclone dust collector 3a.

  In the asphalt composite material manufacturing apparatus of this configuration, when the operation of the V dryer 2 alone is performed, when the aggregate supply amount is small, particularly when it is less than half of the rated amount of the V dryer 2, all of the cutoff dampers 20a and 20b are all installed. It is closed so that the exhaust gas does not flow into one cyclone dust collector 3a. Further, both the shut-off dampers 6b-1 and 6b-2 are fully closed so that the exhaust gas does not flow into the bag filter 4b.

  Thus, the exhaust gas of the V dryer 2 passes through the bag filter 4a through the cyclone dust collector 3b, the ventilation paths 10b, 11, 12a, and the cutoff damper 6a-1, and further, the cutoff damper 6a-2, and the ventilation paths 13a, 14 The air volume adjusting damper 7, the exhaust fan 8 and the chimney 9 are discharged. Therefore, the primary dust collector and the secondary dust collector are used only for the one cyclone dust collector 3b and the bag filter 4a, respectively, and are reduced to 50% of the maximum exhaust gas processing capacity. The passage flow velocity is doubled, and heat dissipation and condensation from the bag filter 4a can be prevented.

  Further, if condensation is less likely to occur in the bag filter 4a, the temperature of the exhaust gas from the V dryer 2 can be lowered, so that the exhaust heat from the V dryer 2 can be reduced. As a result, the amount of heat of the burner 2a that is a heat source of the V dryer 2 can be reduced, and the fuel to be used can be reduced.

  The asphalt mixture production apparatus of the present invention is useful as an apparatus for producing asphalt mixture by mixing asphalt and aggregate. In particular, the present invention is suitable as an asphalt mixture manufacturing apparatus capable of reducing heat radiation from a dust collector and preventing condensation.

It is a schematic block diagram of the asphalt compound-material manufacturing apparatus in 1st Embodiment of this invention. It is a schematic block diagram of the asphalt compound-material manufacturing apparatus in 2nd Embodiment of this invention. It is a schematic block diagram of the conventional asphalt compound-material manufacturing apparatus. It is a schematic block diagram of the conventional asphalt compound-material manufacturing apparatus.

Explanation of symbols

1 Recycling dryer (R dryer)
2 Virgin dryer (V dryer)
3a, 3b Cyclone dust collector 4a, 4b Bag filter 5a, 5b, 7 Air volume adjustment damper 6a-1, 6a-2, 6b-1, 6b-2, 20a, 20b Shut-off damper 8 Air exhauster 9 Chimney 10a, 10b, 11, 12a, 12b, 13a, 13b, 14, 19 Ventilation path 15a, 15b Differential pressure sensor 16a, 16b Differential pressure measuring instrument 17 Load measuring instrument 18 Control device

Claims (5)

A plurality of dust collectors arranged in parallel to the dryer;
An asphalt composite material manufacturing apparatus having a cutoff damper provided in each of the plurality of dust collectors for blocking or passing inflow of exhaust gas from the dryer. The dryer is a virgin dryer and a recycle dryer,
The virgin dryer and the recycle dryer are each provided with a primary dust collector on the downstream side,
The asphalt mixture manufacturing apparatus according to claim 1, wherein the plurality of dust collectors are secondary dust collectors. The dryer is a virgin dryer,
The virgin dryer includes a plurality of primary dust collectors arranged in parallel downstream and an exhaust gas of the virgin dryer to a primary dust collector other than the primary dust collector selected from the plurality of primary dust collectors. A primary cutoff damper for blocking the inflow of
The asphalt mixture manufacturing apparatus according to claim 1, wherein the plurality of dust collectors are secondary dust collectors. The dust collector is a bag filter;
Furthermore, a differential pressure measuring device that measures the differential pressure before and after the filter medium of this bag filter,
The asphalt compound material according to any one of claims 1 to 3, further comprising a control device that controls opening and closing of a shut-off damper provided in each of the bag filters in accordance with a differential pressure value measured by the differential pressure measuring device. Manufacturing equipment. Furthermore, a pressure measuring device for measuring the internal pressure of the dryer;
An exhaust fan disposed downstream of the dust collector;
A load measuring device for measuring the load of the exhaust fan;
2. A control device that controls opening and closing of a shut-off damper provided in each of the dust collectors according to a pressure value measured by the pressure measuring device and a load value measured by the load measuring device. The asphalt compound material manufacturing apparatus in any one of 4 to 4.

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