JP5467595B2 - Asphalt plant - Google Patents

Description

  The present invention relates to an asphalt plant for producing an asphalt mixture that is a road pavement material.

  In the asphalt plant that produces asphalt mixture, a new aggregate heating dryer (hereinafter referred to as “new material”) that heats the new aggregate (hereinafter referred to as “new material”) that is the raw material of the asphalt mixture by exposing it to hot air from the burner. And a waste material heating dryer (hereinafter referred to as "waste material dryer") that heats asphalt pavement waste material (hereinafter referred to as "waste material") excavated by road construction, etc. The exhaust gas derived from the dryer is discharged through a dust collector such as a cyclone or a bag filter and then released into the atmosphere from the chimney. On the other hand, the exhaust gas derived from the waste material dryer contains odor components. Because it is contained, after the dust collection treatment, this odor component is exposed to hot air of about 800 ° C for about 1 to 2 seconds for combustion decomposition. That deodorizing furnace in terms of the deodorizing by way of, and so as to release into the atmosphere from the chimney.

  In this way, in the asphalt plant, a lot of heat energy is used when heat-treating new materials and waste materials with new-material dryers and waste-material dryers, or when deodorizing exhaust gas with a deodorizing furnace. A part of the gas is released into the atmosphere together with the exhaust gas, and heat recovery has been attempted using various methods and means to reduce the amount as much as possible from the viewpoint of energy saving.

  For example, in Patent Document 1 (Japanese Patent Application Laid-Open No. 2009-1996), in an asphalt composite material production facility including a new material dryer, a waste material dryer, and a deodorization furnace, a high temperature exhaust gas derived from the deodorization furnace is used. An apparatus is described in which a part is supplied to a new dryer to recover heat. Moreover, in patent document 2 (Unexamined-Japanese-Patent No. 2009-179935), while supplying a part of high temperature exhaust gas derived | led-out from a deodorizing furnace to a new material dryer similarly to the said document, each burner of each dryer and a deodorizing furnace is used. An apparatus is described which is supplied as combustion air to recover heat.

JP 2009-1996 A JP 2009-179935 A

  As described above, in asphalt plants, various methods and means have been used to recover heat from the exhaust gas and use it effectively, but still a relatively high temperature exhaust gas is released from the chimney. In particular, in the case of an asphalt plant equipped with a deodorizing furnace, the deodorizing process is performed at a high temperature of about 800 ° C., so the exhaust gas temperature emitted from the chimney is also released at a relatively high temperature of about 350 to 400 ° C. Has been. As shown in the above-mentioned patent document, it is possible to recover heat to some extent by supplying a part thereof to a new material dryer or the like, but it is not possible to use the entire amount of exhaust gas, and the remaining remainder The exhaust gas is forced to be discharged from the chimney at a high temperature.

  In view of the above points, an object of the present invention is to provide an asphalt plant that can effectively recover heat from a high-temperature exhaust gas emitted from a chimney of a plant having a deodorizing furnace and can be effectively used.

  In order to solve the above-described problems, in the asphalt plant according to claim 1 of the present invention, deodorization treatment is performed by burning and decomposing odor components in exhaust gas into an exhaust flue of a waste material dryer that heat-treats asphalt pavement waste material. A furnace and a chimney that discharges high-temperature exhaust gas derived from the deodorization furnace to the atmosphere, and an oil tank having a heat retaining function is provided in the vicinity of the chimney, and the oil tank has a hot tank in the tank. Circulating piping that supplies oil along the chimney and circulates it to the oil tank while raising the temperature by heat exchange with exhaust gas, and heating and keeping hot oil in the oil tank heated to a predetermined temperature is effective It is characterized in that it is connected to a supply pipe that circulates and supplies to various plant facilities.

  According to the asphalt plant according to claim 1 of the present invention, a deodorizing furnace for decomposing and treating an odorous component in exhaust gas by combustion decomposition on an exhaust flue of a waste material dryer that heat-treats asphalt pavement waste, and the deodorizing furnace And a chimney that discharges high-temperature exhaust gas derived from the atmosphere to the atmosphere, and an oil tank having a heat retaining function is provided in the vicinity of the chimney, and hot oil in the tank is placed along the chimney in the oil tank. Circulation piping that circulates to the oil tank while raising the temperature by exchanging heat with exhaust gas, and circulates and supplies hot oil in the oil tank that has been heated to a predetermined temperature to plant equipment that is effective for heat insulation The hot oil heated by the recovered heat can be efficiently recovered at the chimney while the exhaust gas heat derived from the deodorizing furnace can be efficiently recovered. Heating insulation Te it is possible to effectively use can be effectively kept the plant facilities of mixed material silo or the like effective asphalt tank and asphalt mixture for storage.

It is a schematic explanatory drawing which shows one Example of the asphalt plant which concerns on this invention.

  In the asphalt plant of the present invention, a new material dryer for heat-treating a new material, a vertical conveying device for feeding the new material heated by the new material dryer, a vibration sieve, an aggregate storage bin, and an aggregate measuring tank In addition to basic equipment such as a plant body consisting of a mixer and the like, a stone powder storage silo for storing stone powder and an asphalt tank for storing asphalt, a mixed silo for temporarily storing the produced asphalt mixture, etc. In the vicinity of the new material dryer, a waste material dryer for heat treating the waste material is provided side by side, a waste material storage bin for storing the waste material heated by the waste material dryer, a waste material measuring tank, and a waste material discharged from the waste material measuring tank for the plant It is provided with supply means for feeding into the mixer of the main body.

  In addition, an exhaust flue for exhaust gas derivation is connected to the new material dryer and waste material dryer, and the exhaust flue of the waste material dryer is connected to the chimney with a deodorizing furnace for deodorizing treatment in the middle. On the other hand, the exhaust flue of the new material dryer is joined to the exhaust flue of the waste material dryer by interposing a dust collector such as a bag filter in the middle of the exhaust flue.

  In addition, an oil tank is provided in the vicinity of the chimney with a heat insulating function such as covering with a heat insulating material, and hot oil in the tank is supplied along the outer peripheral wall of the chimney to supply the exhaust gas to the oil tank. Circulating piping that circulates to the oil tank while raising the temperature by heat exchange, and circulates the hot oil in the tank that has been heated to an appropriate temperature to plant equipment where heat insulation is effective, such as asphalt tanks and compound silos The supply pipe to be supplied is connected.

  When manufacturing the asphalt mixture in the above asphalt plant, the new material and waste material are heated by the new material dryer and the waste material dryer, respectively. The waste material heated by the waste material dryer is stored in the waste material storage bin. Then, a predetermined amount of heated new material and heated waste material are weighed from these aggregate storage bins and waste storage bins into a mixer and mixed with a predetermined amount of asphalt or stone powder supplied from an asphalt tank or stone powder storage silo. Process to produce the desired asphalt mixture. The manufactured asphalt mixture is shipped on a truck or the like, or is put into a compound silo and temporarily stored for shipment.

  On the other hand, the exhaust gas derived from the waste material dryer is introduced into the furnace of the deodorization furnace, exposed to high temperature hot air to burn and decompose odor components and deodorized, and the high temperature exhaust gas derived from this deodorization furnace is It is discharged into the atmosphere from the chimney together with the exhaust gas derived from the wood dryer. At this time, hot oil in the oil tank provided in the vicinity of the chimney is circulated along the chimney surface via the circulation pipe, and hot oil flowing in the circulation pipe during that time and high-temperature exhaust gas discharged from the chimney Then, heat exchange is performed, and eventually the hot oil in the oil tank is replaced with a relatively high temperature of about 200 to 300 ° C.

  Then, the hot oil in the heated oil tank is circulated and supplied to the plant equipment where heat insulation is effective, for example, asphalt tank or compound silo via a supply pipe, and the asphalt or compound silo in the asphalt tank is supplied. Effectively used to keep the asphalt mixture at a predetermined temperature. In addition, although the temperature of hot oil in the tank gradually decreases as heat cannot be recovered by the chimney when there is no plant operation, the oil tank is covered with a heat insulating material to keep the temperature warm. Therefore, for a relatively short period of time, the temperature of the hot oil in the tank can be kept constant and can be used sufficiently effectively for heat insulation of asphalt tanks, compound silos, and the like.

  In this way, hot oil is circulated through the circulation piping provided along the outer wall surface of the chimney of the plant having the deodorization furnace to efficiently recover heat from the high temperature exhaust gas. The oil can be stored in an oil tank and can be suitably used effectively by supplying this hot hot oil to an asphalt tank, a compound silo, or the like, which is a plant facility that is effective for heat insulation.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  In the figure, reference numeral 1 denotes an asphalt plant of the present invention, a new material dryer 2 that heat-treats new materials, a waste material dryer 3 that heat-treats waste materials, and new materials and waste materials that are heated by these dryers. The plant main body 4 etc. which add and mix etc. are comprised as a main body.

  The new material dryer 2 supports a cylindrical drum 5 having a large number of scraping blades (not shown) on the inner periphery thereof so as to rotate on a machine base 6 and a drive device (not shown). The hot air is sent into the drum 5 from the burner 7 provided at one end of the drum 5 and the combustion gas is discharged by the exhaust fan 9 downstream of the exhaust flue 8 at the other end of the drum 5. While sucking and exhausting, new materials such as sand and crushed stone cut out from the new material storage silos 10a, 10b, and 10c are supplied into the drum 5 through the belt conveyor 11, and a predetermined temperature is set while rolling down the drum 5. Until heated.

  Then, the heated new material is discharged from the discharge unit 12 on one end side of the drum 5 and put into the vertical transfer device 13, lifted up to the upper portion of the plant main body 4 by the vertical transfer device 13, and then from the discharge chute 14 To supply. Further, a dust collector 15 such as a bag filter is provided downstream of the exhaust flue 8, and the exhaust gas purified by capturing dust in the exhaust gas is joined to the downstream side of the exhaust flue 20 of the waste dryer 3 described later. In this way, it is discharged from the chimney 29 at the end into the atmosphere.

  The waste material dryer 3 has a structure similar to that of the new material dryer 2, and a cylindrical drum 16 having a scraper blade (not shown) provided around the inner periphery thereof is rotatably supported on the machine base 17. While the flame of the burner 18 provided at one end of the drum 16 is formed in the combustion chamber 19, hot air is sent into the drum 16, and the combustion gas is sucked and exhausted by the exhaust fan 21 downstream of the exhaust flue 20 at the other end of the drum 16. On the other hand, the waste material cut out from the waste material storage silos 22a and 22b is supplied into the drum 16 via the belt conveyor 23, and is heated to a predetermined temperature while rolling down in the drum 16.

  The heated waste material is temporarily stored in a waste material storage bin 24 provided at the other end of the drum 16, and then a predetermined amount is measured in a waste material measuring tank 25. This is supplied to the mixer 43. Further, a dust collector 27 such as a cyclone is provided downstream of the exhaust flue 20, and a deodorization furnace 28 for burning and decomposing asphalt components in the exhaust gas is provided downstream of the exhaust flue 20, and these dust collectors. The exhaust gas which has passed through the deodorizing furnace 28 and the deodorizing furnace 28 and is cleaned is discharged from the chimney 29 at the end to the atmosphere.

  The deodorizing furnace 28 is provided with a burner 30 for maintaining the furnace temperature at a predetermined value at one end, and the exhaust gas introduced into the furnace is exposed to a high temperature atmosphere to burn and decompose asphalt contained in the exhaust gas. The deodorizing furnace 28 controls the combustion amount of the burner 30 so that the temperature in the furnace is maintained at a high temperature of about 800 ° C. so that the asphalt can be completely burned and decomposed, and the exhaust gas passes through the furnace. It is preferable to provide the staying chamber 28a that takes at least 1 to 2 seconds or more.

  31 and 32 are heat exchangers for effectively using the thermal energy held by the high-temperature exhaust gas of about 800 ° C. derived from the deodorizing furnace 28. In the upstream heat exchanger 31, the exhaust gas is exhausted. While the exhaust gas introduced from the flue 20 to the deodorizing furnace 28 is heated, the downstream heat exchanger 32 preheats the combustion air supplied from the combustion air supply fan 33 to the burner 30 of the deodorizing furnace 28. Yes.

  The plant main body 4 receives the new material heated by the new material dryer 2 and sent out from the vertical conveying device 13 and screens it, and stores the new material screened by the vibration screen 34 according to the particle size. Aggregate storage bin 35, aggregate measurement tank 36 for accumulating new materials of each particle size stored in the aggregate storage bin 35, and stone powder measurement for measuring stone powder supplied from a stone powder storage bin 37 by a screw feeder 38 Asphalt measuring tank 42 for measuring asphalt supplied from a supply pump 41 from an asphalt tank 40 having a heating and heat insulation structure around a tank 39, an electric heater, etc., and new materials and stone powder measured in these measuring tanks And a mixer 43 for producing an asphalt mixture by mixing the asphalt with the waste material measured and supplied in the waste material measuring tank 25.

  44 is a composite silo for temporarily storing the produced asphalt mixture, and the outer periphery is covered with a heat insulating material, and an electric heater is provided around it to form a heat insulation structure. Is provided with a discharge port 46. Then, the asphalt mixture discharged from the mixer 43 is once put into the bucket 48 of the horizontal trolley 47 provided at the lower part of the mixer 43, then transferred to the bucket 50 of the skip elevator 49 and lifted to the upper part of the mixture silo 44, and put into the upper part. It is put into the compound silo 44 through the port 45 and stored while being heated and kept warm in preparation for shipment.

  In the vicinity of the chimney 29, there is provided an oil tank 51 having a heat retaining function by covering the outer periphery with a heat insulating material or the like, and hot oil in the tank is supplied to the oil tank 51 by a supply pump 52. A circulation pipe 53 that circulates to the oil tank 51 while gradually raising the temperature by supplying heat and exchanging with the high-temperature exhaust gas discharged from the chimney 29 while feeding along the outer wall surface of the chimney 29 It is connected. At this time, about 350 to 400 ° C. exhaust gas is released from the chimney 29 during plant operation, and the hot oil in the oil tank 51 is reduced by exchanging heat between the exhaust gas and the circulating hot oil for a predetermined time. It is set as the structure replaced by the comparatively high temperature thing about 200-300 degreeC. In this embodiment, the circulation pipe 53 is arranged along the outer wall surface of the chimney 29 so as to exchange heat with the exhaust gas, but may be arranged inside the chimney 29.

  In addition, hot oil heated to the above temperature is sent to the oil tank 51 by supply pumps 54 and 55, and is supplied to an asphalt tank 40, a compound silo 44, or the like, which is a plant facility in which heating and heat insulation is effective. Supply pipes 56 and 57 for circulating supply are connected. The supply pipes 56 and 57 are piped so as to follow the outer wall surfaces of the asphalt tank 40 and the composite silo 44, and by supplying hot hot oil through the supply pipes 56 and 57, The asphalt tank 40 and the composite silo 44 can be effectively heated and kept warm.

  And when manufacturing an asphalt mixture in the asphalt plant 1 of the said structure, new materials, such as sand and crushed stone cut out from the new material storage silos 10a-10c, are supplied to the new material dryer 2, and it exposes to the hot air from the burner 7. The heated new material is sent to the plant main body 4 via the downstream vertical conveyance device 13, and the introduced new material is screened by the vibration sieve 34 in the plant main body 4 to lower the aggregate. Store in the storage bin 35 by particle size. On the other hand, waste material cut out from the waste material storage silos 22 a and 22 b is supplied to the waste material dryer 3, exposed to hot air from the burner 18 and heated to a predetermined temperature, and the heated waste material is stored in the waste material storage bin 24.

  Then, the new material of each particle size is sequentially discharged from the aggregate storage bin 35 to the aggregate measurement tank 36, accumulated and weighed into the mixer 43, and the waste material is also discharged from the waste storage bin 24 to the waste measurement tank 25 for measurement. Then, the mixture is put into the mixer 43, and further, the stone powder measured in the stone powder measuring tank 39 and the asphalt measured in the asphalt measuring tank 42 are put into the mixer 43 and mixed for a predetermined time to produce a desired asphalt mixture. . Then, the manufactured asphalt mixture is discharged from the mixer 43 and shipped on a truck or the like, or when there is room until shipment, it is put into the composite silo 44 through the horizontal trolley 47, the skip elevator 49, etc. Temporarily store and prepare for shipment.

  The exhaust gas derived from the exhaust flue 8 of the new material dryer 2 is collected by the downstream dust collector 15 and then merged with the downstream side of the exhaust flue 20 of the waste material dryer 3, while the exhaust gas from the waste material dryer 3 is exhausted. The exhaust gas led out from the flue 20 is introduced into a downstream deodorizing furnace 28 and exposed to high-temperature hot air of about 800 ° C. for about 1 to 2 seconds to burn and decompose odorous components and generate deodorization. A part of the high-temperature exhaust gas to be recovered is heat-recovered by the heat exchangers 31 and 32, and then discharged from the chimney 29 at the end together with the exhaust gas from the new material dryer 2 into the atmosphere.

  At this time, hot oil is supplied from the oil tank 51 provided in the vicinity of the chimney 29 through the circulation pipe 53 so as to follow the outer wall surface of the chimney 29, and the high temperature of about 350 to 400 ° C. discharged from the chimney 29. It is circulated to the oil tank 51 while being gradually heated up by exchanging heat with the exhaust gas (see the two-dot chain line arrow A in the figure), and the hot oil in the tank is finally about 200 to 300 ° C. It will be replaced with a relatively hot one. Then, the hot oil in the oil tank 51 thus warmed is circulated and supplied to the plant equipment where heating and heat insulation is effective, for example, to the asphalt tank 40 and the composite silo 44 via the supply pipes 56 and 57, and the asphalt in the tank Effectively used to keep the asphalt mixture in the silo at a predetermined temperature.

  In these asphalt tanks 40 and composite silos 44, it is basically necessary to keep the asphalt or asphalt mixture as the contents constant at a constant temperature (for example, about 170 ° C.). Although it is heated and kept warm, as described above, it is almost limited to the time of plant operation, but by supplying hot hot oil to the tank and silo outer wall surface, it is possible to assist warming with an electric heater and use electricity A reduction in the amount can be expected.

  In addition, since heat cannot be recovered by the chimney 29 when the plant is not in operation, the temperature of the hot oil in the oil tank 51 is inevitably lowered. For this reason, the temperature of the hot oil in the tank can be kept constant for a relatively short period of time and can be used sufficiently effectively for heat retention of the asphalt tank 40, the composite silo 44, and the like. In the present embodiment, the asphalt tank 40 and the composite silo 44 are given as examples of plant equipment to be heated and kept warm with high-temperature oil. However, the present invention is not limited to these. For example, heated aggregate is supplied. Similarly, high-temperature hot oil may be supplied to the outer periphery of the aggregate storage bin 35 or the like of the plant body 4 to maintain the temperature.

  Thus, according to the apparatus of the said structure, heat recovery can be efficiently carried out from the high temperature exhaust gas derived | led-out from the chimney 29 of the asphalt plant 1 which has the deodorizing furnace 28, and the collect | recovered thermal energy is heat-retained as high temperature hot oil. It can be stored in an oil tank 51 having a structure, and can be used effectively by supplying this hot hot oil to an asphalt tank 40, a compound silo 44, or the like, which is a plant facility that is effective for heat insulation. Energy saving can be expected.

DESCRIPTION OF SYMBOLS 1 ... Asphalt plant 2 ... New material dryer 3 ... Waste material dryer 4 ... Plant main body 20 ... Exhaust flue 28 ... Deodorizing furnace 29 ... Chimney 31, 32 ... Heat exchanger 40 ... Asphalt tank (plant equipment)
44 ... Compound material silo (plant equipment) 51 ... Oil tank 53 ... Circulation piping 56, 57 ... Supply piping

Claims (1)

  A deodorizing furnace that burns and decomposes odorous components in exhaust gas to deodorize the exhaust flue of a waste dryer that heats asphalt pavement waste, and a chimney that discharges high-temperature exhaust gas derived from the deodorizing furnace to the atmosphere In addition, an oil tank having a heat retaining function is provided in the vicinity of the chimney, and hot oil in the tank is supplied along the chimney to raise the temperature by heat exchange with the exhaust gas. An asphalt plant characterized by connecting a circulation pipe that circulates to an oil tank and a supply pipe that circulates and supplies hot oil in the oil tank that has been heated to a predetermined temperature to a plant facility that is effectively heated and insulated.

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