JP5414109B2 - Asphalt plant - Google Patents

Description

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

  Asphalt plant factories that produce asphalt mixtures include new material heating dryers (hereinafter referred to as “new materials dryers”) that heat new aggregates (hereinafter referred to as “new materials”) and asphalts that are dug up due to road construction, etc. There are many places where both waste material heating dryers (hereinafter referred to as “waste material dryers”) that heat pavement waste materials (hereinafter referred to as “waste materials”) are installed.

  Such asphalt plant factories produce asphalt mixtures that use 100% of new materials and asphalt mixtures in which waste materials are mixed in various proportions of new materials. Recently, there is a tendency to increase the mixing rate of waste materials. For example, there are some in which the mixing ratio of waste materials exceeds 50%. And when increasing the mixing ratio of waste material in this way, while the waste material dryer is operating at full capacity, the new material dryer may be appropriately lowered or temporarily stopped depending on the mixing ratio of the waste material. There are many cases where a lot of driving is performed.

  By the way, when the waste material is heated by the waste material dryer, an odor component is contained in the exhaust gas, and a deodorization furnace may be installed to burn and decompose the odor component. In this deodorization furnace, exhaust gas derived from a waste material dryer is introduced into the furnace, and the odor component contained in the exhaust gas is exposed to hot air of about 800 ° C. for about 1 to 2 seconds to be decomposed by combustion. It is. At this time, since the exhaust gas derived from the deodorization furnace is high temperature, for example, the exhaust gas to be recovered by a heat exchanger and introduced into the deodorization furnace or the combustion air to the burner of the deodorization furnace is preheated, or It has been proposed to use heat efficiently by supplying high-temperature exhaust gas to the burner side of the new material dryer and using it for heating the new material even after passing through the heat exchanger (Patent Document 1). ).

JP 2009-1996 A

  However, as described above, recently, there is a tendency to increase the mixing ratio of waste material, and there are not a few cases where operation of dropping a new material dryer or temporarily stopping operation is performed. After recovering a certain amount of high-temperature exhaust gas heat derived from the deodorization furnace with a heat exchanger, it cannot be used for heating the new material by supplying it to the new material dryer as in the above-mentioned Patent Document 1, as it is. The exhaust gas heat cannot be used sufficiently effectively because it is forced to be released into the atmosphere.

  In view of the above points, an object of the present invention is to provide an asphalt plant capable of effectively utilizing high-temperature exhaust gas heat derived from a deodorizing furnace even when a new material dryer is not operated during operation of a waste material dryer.

  In order to solve the above problems, an asphalt plant according to claim 1 is a new material dryer that heats a new material cut out from a new material storage silo, and a vertical conveying device that sends out the new material heated by the new material dryer. A plant body comprising a vibration sieve, an aggregate storage bin, an aggregate measuring tank, and a mixer for receiving new material sent out by the vertical conveying device, a waste material dryer for heating the waste material, and a waste material heated by the waste material dryer A waste material storage bin for storing the waste material, a waste material measuring tank, a supply means for introducing the waste material discharged from the waste material measuring tank into the mixer, and a deodorizing furnace for burning and decomposing odor components in the exhaust gas derived from the waste material dryer In the asphalt plant provided, a branch duct is connected to the exhaust duct downstream of the deodorization furnace, and the other end of the branch duct is connected to the burner side of the new material dryer. A high-temperature exhaust gas derived from the deodorizing furnace is introduced into the new material dryer, and the vertical conveying device is provided with a branch chute having a path changing means, and is discharged to the branch chute side below the branch chute. It is characterized by having a transport device for returning the new material to be sent back to the new material storage silo.

  According to the asphalt plant of the first aspect of the present invention, the branch duct is connected to the exhaust duct downstream of the deodorization furnace, and the other end of the branch duct is connected to the burner side of the new material dryer to remove the deodorization furnace. A high-temperature exhaust gas to be led out is introduced into a new material dryer, and the vertical conveying device is provided with a branch chute having a path changing means, and a new one discharged to the branch chute side is provided below the branch chute. Since it is equipped with a transfer device that sends the material back to the new material storage silo, even if there is no operation of the new material dryer, any new material is cut out from the new material storage silo, and only the drum is rotated without burning the burner. By circulating through the new material dryer, vertical conveying device, branch chute, and conveying device to be performed, and introducing the high temperature exhaust gas derived from the deodorizing furnace in this state to the new material dryer By heating any new materials to a suitable temperature can be allowed to pre-drying, it is possible to sufficiently effectively utilize the exhaust gas heat.

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 that heats new material such as sand and crushed stone cut out from a new material storage silo, a vertical conveying device that delivers new material heated by the new material dryer, and a vibration Plant body consisting of sieve, aggregate storage bin, aggregate measuring tank, mixer, etc., waste material dryer for heating waste material, waste material storage bin for storing waste material heated by the waste material dryer, waste material measuring tank, waste material measurement Supplying means for introducing waste material discharged from the tank into the mixer of the plant main body, and a deodorizing furnace for burning and decomposing odor components in the exhaust gas derived from the waste material dryer.

  Also, a branch duct is connected to the exhaust duct downstream of the deodorization furnace, and the other end of the branch duct is connected to the burner side of the new material dryer so that the high-temperature exhaust gas derived from the deodorization furnace is put into the new material dryer. A branch chute is provided on the discharge chute of the vertical transfer device, which is provided with a switching damper which is a path changing means so as to be rotatable. A belt conveyor is provided as a conveying device for sending the material back to the new material storage silo.

  And when manufacturing an asphalt mixture in the above asphalt plant, for example, when both a new material dryer and a waste material dryer are operated, new material such as sand and crushed stone cut out from a new material storage silo is used for the new material dryer. While supplying and heating with the burner provided in the new material dryer, the waste material is supplied to the waste material dryer and heated with the burner provided in the waste material dryer. The exhaust gas containing the odor component derived from the waste material dryer is combusted and decomposed in the downstream deodorization furnace, and the high temperature exhaust gas generated at that time is guided to the downstream exhaust duct, part of which is a branch duct. It is introduced into the new material dryer through the heat exchanger and used for heating the new material.

  When only the waste dryer is operated and the new dryer is stopped, the waste dryer is supplied to the waste dryer in the same manner as described above and heated by the burner provided for the waste dryer, while the burner is used for the new dryer. Stops and rotates only the drum, and also rotates the discharge chute switching damper of the downstream vertical conveying device to switch the discharge path to the branch chute side and extends from the lower part of the branch chute to the new material storage silo With the conveyor running, any new material, such as sand, is cut out from the new material storage silo and supplied to the new material dryer, and the original new material storage silo is passed through the vertical conveyor, branch chute, and belt conveyor. Circulate back to In the new material dryer, as described above, a part of the high-temperature exhaust gas generated in the deodorizing furnace is introduced through the branch duct, and the circulating sand is heated to an appropriate temperature and preliminarily dried. To use.

  In this way, the other end of the branch duct connected to the exhaust duct downstream of the deodorizing furnace is connected to the burner side of the new material dryer, and the vertical conveying device downstream of the new material dryer has a branch chute equipped with a path changing means. In addition, since a transport device that sends back the new material discharged to the branch chute side to the original new material storage silo is provided below the branch chute, the new chute can be stored by appropriately switching the branch chute path changing means. Arbitrary new material cut out from the silo can be circulated back to the original new material storage silo via the new material dryer, vertical conveying device, branch chute, and conveying device. If the hot exhaust gas to be introduced is introduced into the new material dryer, the circulating new material can be heated to an appropriate temperature and preliminarily dried. If operating the both ear course, even when stopping the operation of the new materials dryer with only is operated waste drier example, the high temperature exhaust gas heat derived from the deodorizing furnace can be used without waste effectively.

  Embodiments of the present invention will be described below with reference to the drawings.

  In the figure, reference numeral 1 denotes an asphalt plant of the present invention, a new material dryer 2 for heating new materials, a waste material dryer 3 for heating waste materials, and asphalt and stone powder added to the new materials and waste materials heated by these dryers. The plant body 4 and the like to be mixed are mainly configured.

  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 sucked by the exhaust fan 9 downstream of the exhaust duct 8 at the other end of the drum 5. While exhausting, new materials such as sand and crushed stone cut from the new material storage silos 10a, 10b, and 10c are supplied into the drum 5 via the belt conveyor 11, and the temperature reaches a predetermined temperature while rolling down the drum 5. Heat.

  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 is provided downstream of the exhaust duct 8, and the exhaust gas purified by capturing dust in the exhaust gas is discharged from the chimney 16 to the atmosphere.

  The waste material dryer 3 has a structure similar to that of the new material dryer 2, and a cylindrical drum 17 having a scraper blade (not shown) provided around the inner periphery thereof is rotatably supported on a machine base 18. While the flame of the burner 19 provided at one end of the drum 17 is formed in the combustion chamber 20, hot air is sent into the drum 17, and the combustion gas is sucked and exhausted by the exhaust fan 22 downstream of the exhaust duct 21 at the other end of the drum 17. On the other hand, the waste material cut out from the waste material storage silos 23a and 23b is supplied into the drum 17 via the belt conveyor 24, and is heated to a predetermined temperature while rolling down the inside of the drum 17.

  The heated waste material is temporarily stored in a waste material storage bin 25 provided at the other end of the drum 17, and then a predetermined amount is measured in a waste material measuring tank 26. 39. A dust collector 28 such as a cyclone is provided downstream of the exhaust duct 21, and a deodorizing furnace 29 for burning and decomposing asphalt components in the exhaust gas is provided downstream of the exhaust duct 21. The exhaust gas that has passed through the deodorizing furnace 29 and has been purified is discharged from the chimney 30 into the atmosphere.

  The deodorizing furnace 29 is provided with a burner 31 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 combust and decompose the asphalt contained in the exhaust gas. The deodorizing furnace 29 controls the combustion amount of the burner 31 so that the furnace temperature is maintained at a high temperature of, for example, 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 have a staying chamber 29a that takes at least 1 to 2 seconds or more to do so.

  32 and 33 are heat exchangers for effectively using the heat of the exhaust gas held by the exhaust gas having a high temperature of about 800 ° C. led out from the exhaust duct 34 of the deodorizing furnace 29. In 32, the temperature of the exhaust gas introduced from the exhaust duct 21 to the deodorizing furnace 29 is raised, while in the downstream heat exchanger 33, the combustion air supplied from the combustion air supply fan 35 to the burner 31 of the deodorizing furnace 29 is preheated. I am trying.

  The plant main body 4 receives the new material heated by the new material dryer 2 and sent out from the vertical transfer device 13 and screens it, and stores the new material screened by the vibration screen 36 according to the particle size. In the aggregate storage bin 37, an aggregate measuring tank 38 for accumulating and weighing new materials stored in the aggregate storage bin 37, the new material measured in the aggregate measuring tank 38 and the waste material measuring tank 26 A mixer 39 and the like for producing an asphalt mixture by mixing the waste material to be weighed and separately metered asphalt or stone powder are provided.

  A branch duct 40 is connected to the exhaust duct 34 downstream of the deodorizing furnace 29, and the other end of the branch duct 40 is connected to the burner 7 side of the new material dryer 2. Is provided with an exhaust fan 41, and high-temperature exhaust gas led out from the deodorizing furnace 29 is introduced into the new material dryer 2 for use.

  Further, the discharge chute 14 of the vertical conveying device 13 is provided with a branch chute 43 that is rotatably provided with a switching damper 42 that is a path changing means, and is discharged to the branch chute 43 side below the branch chute 43. A belt conveyor 44 is provided as a transfer device that sends the new material back to the original new material storage silos 10a to 10c.

  In the present embodiment, the switching damper is adopted as a path changing means for switching the path of the new material sent out by the vertical conveyance device 13 to the branch chute 43 side, but the present invention is not limited to this. For example, a slide gate or the like can be suitably employed. Further, in this embodiment, the path changing means and the branch chute are provided in the discharge chute 14 on the outlet side of the vertical conveyance device 13, but the new material dryer 2 discharge unit 12 on the inlet side of the vertical conveyance device 13 is provided. In this case as well, a conveying device for returning the new material to the original new material storage silos 10a to 10c is provided below the branch chute.

  And when manufacturing an asphalt mixture in the asphalt plant 1 of the said structure, when operating both the new material dryer 2 and the waste material dryer 3, for example, and heating both a new material and a waste material with a burner, a new material dryer 2 is supplied with new materials such as sand and crushed stones cut from the new material storage silos 10a to 10c, heated to a predetermined temperature by the burner 7, sent to the plant body 4 by the vertical transfer device 13, While being sieved and stored in the aggregate storage bin 37 according to the particle size, the waste dryer 3 is supplied with the waste material cut out from the waste material storage silos 23a to 23b and heated to a predetermined temperature by the burner 19 to the waste material storage bin 25. Store. Then, the new material of each particle size is sequentially discharged from the aggregate storage bin 37 to the aggregate measuring tank 38, accumulated and weighed into the mixer 39, and the waste material is also discharged from the waste storage bin 25 to the waste measuring tank 26 for measurement. Then, the asphalt and stone powder weighed separately are put into the mixer 39 and mixed for a predetermined time to produce a desired asphalt mixture.

  At this time, the exhaust gas containing the asphalt component derived from the waste material dryer 3 is combusted and decomposed in the downstream deodorizing furnace 29, and the hot exhaust gas generated at that time is derived from the downstream exhaust duct 34. The part is introduced into the new material dryer 2 via the branch duct 40 and is effectively used for heating the new material.

  Further, when only the waste material dryer 3 is operated and only the waste material is heated by the burner, the waste material dryer 3 is supplied with the waste material cut out from the waste material storage silos 23a to 23b and heated, while the new material dryer is heated. 2, only the drum 5 is rotated without burning the burner 7, and the switching chute 42 of the discharge chute 14 of the vertical conveying device 13 is rotated to switch the path of the discharge chute 14 to the branch chute 43 side. The belt conveyor 44 provided below the branch chute 43 is operated, and in that state, among the new material storage silos 10a to 10c, for example, sand is cut out from the storage silo 10a for sand storage and supplied to the new material dryer 2 Then, it is sent back to the original storage silo 10a for sand storage through the vertical conveyance device 13, the branch chute 43 and the belt conveyor 44. Circulating in the (see two-dot chain line arrow in the figure).

  Then, a part of the high-temperature exhaust gas generated when the exhaust gas of the waste material dryer 3 is combusted and decomposed in the deodorizing furnace 29 is introduced into the new material dryer 2 through the branch duct 40 in the same manner as described above. The sand supplied to is effectively used for pre-drying by heating to an appropriate temperature. On the other hand, the pre-dried sand is discharged from the discharge chute 14 of the vertical conveyance device 13, but is discharged to the branch chute 43 side from the middle, sent back to the original storage silo 10 a for storing sand by the belt conveyor 44, and again. Stored.

  Thus, not only when both the new material dryer and the waste material dryer are operated and both the new material and the waste material are heated by the burner, but also when only the waste material dryer is operated and the operation of the new material dryer is stopped. While circulating any new material cut from the new material storage silo through the new material dryer, vertical conveying device, branch chute, and conveying device, high-temperature exhaust gas derived from the deodorizing furnace is introduced into the new material dryer By doing so, the new material can be heated to an appropriate temperature and preliminarily dried, and the exhaust gas heat can be used effectively without waste.

  The new material supplied when the new material dryer is stopped and preliminarily dried may be any aggregate, but as in this example, the water content ratio is increased by predrying sand having a relatively high water content ratio and large variations. The asphalt mixture to be produced can be expected to improve the quality.

DESCRIPTION OF SYMBOLS 1 ... Asphalt plant 2 ... New material dryer 3 ... Waste material dryer 4 ... Plant main body 7, 19, 31 ... Burner 10a, 10b, 10c ... New material storage silo 12 ... Discharge part 13 ... Vertical conveyance apparatus 14 ... Discharge chute 25 ... Waste material Storage bin 26 ... Waste material measuring tank 27 ... Conveyor (supply means) 29 ... Deodorizing furnace 32, 33 ... Heat exchanger 34 ... Exhaust duct 35 ... Combustion air supply fan 36 ... Vibrating sieve 37 ... Aggregate storage bin 38 ... Aggregate Weighing tank 39 ... Mixer 40 ... Branch duct 42 ... Switching damper (path changing means) 43 ... Branch chute 44 ... Belt conveyor (conveying device)

Claims (1)

  New material dryer for heating new material cut out from new material storage silo, vertical conveying device for feeding new material heated by the new material dryer, vibrating sieve for receiving new material delivered by the vertical conveying device, bone The main body of the material storage bin, the aggregate measuring tank, and the mixer, the waste material dryer for heating the waste material, the waste material storage bin for storing the waste material heated by the waste material dryer, the waste material measuring tank, and the waste material measuring tank are discharged. In an asphalt plant comprising a supply means for introducing waste material into the mixer and a deodorization furnace for burning and decomposing odor components in exhaust gas derived from the waste material dryer, a branch duct is connected to an exhaust duct downstream of the deodorization furnace The other end of the branch duct is connected to the burner side of the new material dryer so that high-temperature exhaust gas derived from the deodorizing furnace is introduced into the new material dryer. In addition, the vertical conveying device is provided with a branch chute having a path changing means, and at the lower part of the branch chute is provided with a conveying device that sends back the new material discharged to the branch chute side to the new material storage silo. A characteristic asphalt plant.

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