JP7201520B2 - Molding sand heat exchange device - Google Patents

Description

The present invention relates to a heat exchange device for foundry sand.

In Patent Document 1, a cylindrical transport pipe forming a heat exchange zone for cooling foundry sand (also referred to as old sand) generated when a mold is crushed is provided, and suction is applied to one end of the transport pipe. A cooling device for foundry sand to which the suction port of a dust collector is connected is described. Specifically, in the cooling device, the transport pipe is formed in the vertical direction, and an updraft is formed inside the transport pipe by suction by the suction dust collector, and the updraft and the foundry sand are brought into direct fluid contact. This cools the foundry sand.

JP 2011-224599 A

However, in the cooling device of Patent Document 1, the foundry sand is transported by sucking the inside of the transport pipe with a suction dust collector. In this case, the flow of fluidized sand in the transport pipe is a uniform flow, and the amount of molding sand transported relative to the amount of air sucked is small, so the transportation speed of the molding sand is, for example, 20 m/s. degree and speed. Therefore, there is a possibility that the inside of the transport pipe will wear out quickly.

SUMMARY OF THE INVENTION The present invention has been made to solve such problems, and it is an object of the present invention to provide a heat exchange apparatus for foundry sand that is capable of suppressing abrasion inside a transport pipe.

A heat exchange device for molding sand according to the present invention includes a supply port through which molding sand is supplied, flowing air having a temperature different from that of the molding sand is supplied from a lower portion, and the height decreases as the distance from the supply port increases. A heat exchange tank in which a plurality of partition plates are erected, and a pipe erected along the vertical direction of the heat exchange tank at a position on the opposite side of the heat exchange tank from the supply port side of the heat exchange tank, a heat exchange tube whose lower part is inserted into the heat exchange tank; and a compressed air supply that supplies compressed air having a temperature different from that of the foundry sand toward the inside from the lower side of the heat exchange tube. and

According to the molding sand heat exchange apparatus of the present invention, in the heat exchange tank, the molding sand in the heat exchange tank is fluidized by the fluidized air supplied from the lower part, and the plurality of partition plates become lower as they move away from the supply port. Therefore, the foundry sand moves away from the supply port. In addition, the foundry sand that has moved to the vicinity of the bottom of the heat exchange tube is sent into the heat exchange tube by the compressed air that is supplied toward the inside of the heat exchange tube, and moves upward in the heat exchange tube. Therefore, the flow of the foundry sand inside the heat exchange tank and inside the heat exchange tubes becomes, for example, about 3 m/s or more and 5 m/s or less, and abrasion inside the heat exchange tank or the heat exchange tubes can be suppressed. can. Further, since the temperature of the fluidizing air and the compressed air is different from the temperature of the foundry sand, the foundry sand can be heat-exchanged in the heat exchange tank and the heat exchange tube. Therefore, it is possible to provide a heat exchange device for foundry sand that can suppress abrasion inside the transport pipe.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram schematically showing a cross-section of a method for regenerating foundry sand according to Embodiment 1 of the present invention and an example of a heat exchange apparatus according to Embodiment 1 of the present invention as viewed from the side; FIG. 4 is a diagram schematically showing a cross section of an example of the lower heat exchange zone of the heat exchange device according to Embodiment 1 of the present invention, viewed from the upper surface side; FIG. 3 is a diagram schematically showing a cross section of the lower structure of the heat exchange tube according to Embodiment 1 of the present invention, viewed from the side.

Embodiment 1
BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 schematically shows a cross section viewed from the side of an example of a method for regenerating foundry sand S according to Embodiment 1 of the present invention and a heat exchange device 100 according to Embodiment 1 of the present invention. Further, FIG. 2 schematically shows a cross section of an example of the lower heat exchange zone Z1 of the heat exchange device 100 according to Embodiment 1 as viewed from above. Moreover, FIG. 3 schematically shows a cross section of the lower structure of the heat exchange tube 107 according to Embodiment 1 as viewed from the side. 1 to 3, the direction of flow of molding sand S is indicated by solid arrows, and the direction of flow of flowing air (air) is indicated by bold arrows.

As shown in FIG. 1, the method for regenerating the foundry sand S includes a step of recovering the foundry sand S generated when the mold is crushed (step S1), a step of crushing the foundry sand S (step S2), A step of heating the foundry sand S (step S3), a step of cooling the foundry sand S (step S4), a step of polishing the foundry sand S (step S5), a step of classifying the foundry sand S (step S6), etc. .
The heat exchange device 100 according to the present invention can be used in the step of heating the molding sand S (step S3), the step of cooling the molding sand S (step S4), and the like. Embodiment 1 describes an example in which the heat exchange device 100 is used in the step of cooling the foundry sand S (step S4).

Further, as shown in FIG. 1, the heat exchange device 100 includes a lower heat exchange zone Z1, a transport heat exchange zone Z2, and an upper heat exchange zone Z3. Then, the transport heat exchange zone Z2 performs heat exchange of the foundry sand S while transporting the foundry sand S from the lower heat exchange zone Z1 to the upper heat exchange zone Z3. The upper heat exchange zone Z3 may be provided as required.

Specifically, the heat exchange device 100 includes a lower heat exchange tank 101, partition plates 102A, 102B, and 102C, a lower fluidized air box 103, a lower perforated plate 104, a lower fluidized air supply pipe 105, and a compressor as a compressed air supply unit. An air supply pipe 106, a heat exchange pipe 107, an upper heat exchange tank 108, partition plates 109A, 109B, 109C, an upper fluidized air box 110, an upper perforated plate 111, an upper fluidized air supply pipe 112, and the like.
The lower heat exchange zone Z1 includes a lower heat exchange tank 101, partition plates 102A, 102B, and 102C, a lower fluidized air box 103, a lower perforated plate 104, a lower fluidized air supply pipe 105, and the like.
The transport heat exchange zone Z2 also includes a compressed air supply pipe 106, a heat exchange pipe 107, and the like.
The upper heat exchange zone Z3 includes an upper heat exchange tank 108, partition plates 109A, 109B, 109C, an upper fluidized air box 110, an upper perforated plate 111, an upper fluidized air supply pipe 112, and the like.
The number of partition plates 102A, 102B, 102C and partition plates 109A, 109B, 109C provided is not limited to the number shown in FIGS. The number of sheets of 109A, 109B, and 109C may be different.

The lower heat exchange tank 101 has a supply port 101A through which the foundry sand S is supplied. The supply port 101A, as shown in FIGS. 1 and 2, for example, protrudes from the side surface of the lower heat exchange tank 101 and is inclined upward as it separates from the side surface of the lower heat exchange tank 101. So, it is provided. Also, the supply port 101A is provided on the upper side of the side surface of the lower heat exchange tank 101 .

The lower part of the lower heat exchange tank 101 is connected to the lower fluidized air box 103 via the lower perforated plate 104 . When flowing air is supplied into the lower fluidized air box 103 through the lower fluidized air supply pipe 105 , the fluidized air enters the lower heat exchange tank 101 through the holes of the lower perforated plate 104 . That is, flowing air is supplied from the lower part of the lower heat exchange tank 101 . The temperature of the fluidizing air is controlled so as to be different from the temperature of the foundry sand S supplied to the lower heat exchange tank 101 . When the temperature of the fluidizing air is lower than the temperature of the foundry sand S supplied to the lower heat exchange tank 101, the lower heat exchange zone Z1 cools the foundry sand S. Conversely, when the temperature of the flowing air is higher than the temperature of the molding sand S supplied to the lower heat exchange tank 101, the lower heat exchange zone Z1 heats the molding sand S.
The lower fluidized air supply pipe 105 extends from the opposite side of the lower heat exchange tank 101 to the supply port 101A and is connected to the lower fluidized air box 103 . Specifically, the lower fluidized air supply pipe 105 is branched and connected to the lower fluidized air box 103 for each of a plurality of heat exchange zones partitioned by a plurality of partition plates 102A, 102B, and 102C, which will be described later.

A plurality of partition plates 102A, 102B, and 102C are erected in the lower heat exchange tank 101. As shown in FIG. Further, the surfaces of the plurality of partition plates 102A, 102B, and 102C are substantially perpendicular to the direction from the supply port 101A toward the heat exchange tubes 107, respectively. Thereby, the inside of the lower heat exchange tank 101 and the inside of the lower fluidized air box 103 are divided into a plurality of heat exchange zones.
Also, the heights of the plurality of partition plates 102A, 102B, and 102C decrease with increasing distance from the supply port 101A. As a result, the casting sand S in the lower heat exchange tank 101 is caused to flow by the flowing air supplied from the lower part of the lower heat exchange tank 101, and the casting sand S moves away from the supply port 101A.

The compressed air supply pipe 106 is inserted inside the lower heat exchange tank 101 as shown in FIGS. Also, the heat exchange pipe 107 is a pipe erected along the vertical direction of the lower heat exchange tank 101 at a position opposite to the supply port 101A side of the lower heat exchange tank 101 . The lower part of the heat exchange tube 107 is inserted inside the lower heat exchange tank 101 . The tip of the compressed air supply pipe 106 is directed toward the inside of the lower tip 107A of the heat exchange pipe 107 . At least one or more nozzle holes are provided at the tip of the compressed air supply pipe 106 . Therefore, compressed air is supplied from the lower side of the heat exchange tube 107 toward the inside through the compressed air supply tube 106 . As a result, the foundry sand S near the bottom of the heat exchange tube 107 is sent into the heat exchange tube 107 with the flow of the compressed air, and moves upward through the heat exchange tube 107 . The temperature of the compressed air is controlled so as to be different from the temperature of the foundry sand S fed into the heat exchange tube 107 . When the temperature of the compressed air is lower than the temperature of the foundry sand S fed into the heat exchange tube 107, the transport heat exchange zone Z2 cools the foundry sand S. Conversely, when the temperature of the compressed air is higher than the temperature of the foundry sand S fed into the heat exchange tube 107, the transport heat exchange zone Z2 heats the foundry sand S.

Further, as shown in FIG. 3, the tip portion 107A of the heat exchange tube 107 has a shape in which the diameter increases toward the lower end. In other words, the tip portion 107A of the heat exchange tube 107 has a trumpet shape. As a result, the foundry sand S positioned near the bottom of the heat exchange tube 107 can be sent into the heat exchange tube 107 more efficiently. That is, the transport efficiency of the foundry sand S in the heat exchange tube 107 can be improved. The transportation efficiency of the molding sand S of the heat exchange pipe 107 is (amount of molding sand S transported by the heat exchange pipe 107 within a predetermined period)/(compressed air supplied by the compressed air supply pipe 106 within a predetermined period). air volume). Here, the amount of foundry sand S and the amount of compressed air may be either volume or mass.
Also, the upper end of the tip portion of the compressed air supply pipe 106 is located above the lower end of the tip portion 107A of the heat exchange pipe 107 . Accordingly, the molding sand S can be sent into the heat exchange pipe 107 more reliably by the compressed air supplied toward the inside of the heat exchange pipe 107 through the compressed air supply pipe 106 .
The upper portion of the heat exchange tube 107 is inserted inside the upper heat exchange tank 108 . As a result, the foundry sand S that has moved upward through the heat exchange tube 107 is supplied into the upper heat exchange tank 108 .

The upper heat exchange tank 108 has an outlet 108A through which the foundry sand S is discharged. As shown in FIG. 1, for example, the outlet 108A protrudes from the side surface of the upper heat exchange tank 108 and slopes downward as it moves away from the side surface of the upper heat exchange tank 108. is provided. Also, the outlet 108A is provided on the lower side of the side surface of the upper heat exchange tank 108 .

The lower part of the upper heat exchange tank 108 is connected to the upper fluidized air box 110 via the upper perforated plate 111 . When the fluidized air is supplied into the upper fluidized air box 110 through the upper fluidized air supply pipe 112 , the fluidized air enters the upper heat exchange tank 108 through the holes of the upper perforated plate 111 . That is, flowing air is supplied from the lower part of the upper heat exchange tank 108 . The temperature of the fluidizing air is controlled so as to be different from the temperature of the foundry sand S supplied from the heat exchange pipe 107 to the upper heat exchange tank 108 . When the temperature of the fluidizing air is lower than the temperature of the molding sand S supplied to the upper heat exchange tank 108, the molding sand S is cooled in the upper heat exchange zone Z3. Conversely, when the temperature of the fluidizing air is higher than the temperature of the molding sand S supplied to the upper heat exchange tank 108, the upper heat exchange zone Z3 heats the molding sand S.
The upper fluidized air supply pipe 112 extends from the side opposite to the discharge port 108A of the upper heat exchange tank 108 and is connected to the upper fluidized air box 110 . Specifically, the upper fluidized air supply pipe 112 is branched and connected to the upper fluidized air box 110 for each of a plurality of heat exchange zones partitioned by a plurality of partition plates 109A, 109B, and 109C, which will be described later.

A plurality of partition plates 109A, 109B, and 109C are erected in the upper heat exchange tank 108 . Further, the surfaces of the partition plates 109A, 109B, and 109C are substantially perpendicular to the direction from the heat exchange tube 107 toward the discharge port 108A. Thereby, the inside of the upper heat exchange tank 108 and the inside of the upper fluidized air box 110 are divided into a plurality of heat exchange zones.
Also, the heights of the plurality of partition plates 109A, 109B, and 109C decrease with increasing distance from the heat exchange tube 107 . As a result, the molding sand S in the upper heat exchange tank 108 is fluidized by the flowing air supplied from the lower part of the upper heat exchange tank 108 , and the molding sand S moves away from the heat exchange tube 107 .

According to the heat exchange device 100 according to Embodiment 1 described above, in the lower heat exchange tank 101, the casting sand S in the lower heat exchange tank 101 is caused to flow by the flowing air supplied from the bottom, and the plurality of partitions are formed. Since the plates 102A, 102B, and 102C become lower as they move away from the supply port 101A, the foundry sand S moves away from the supply port 101A. In addition, the foundry sand S that has moved to the vicinity of the bottom of the heat exchange tube 107 is sent into the heat exchange tube 107 by the compressed air supplied toward the inside of the heat exchange tube 107, and the heat exchange tube 107 moves upward. Moving. Therefore, the flow of the foundry sand S inside the lower heat exchange tank 101 and inside the heat exchange tubes 107 is, for example, approximately 3 m/s or more and 5 m/s or less. wear can be suppressed. Further, since the temperature of the fluidizing air and the compressed air is different from the temperature of the molding sand S, the molding sand S can be heat-exchanged in the lower heat exchange tank 101 and the heat exchange pipes 107 . Therefore, it is possible to provide the heat exchange device 100 for the foundry sand S, which is capable of suppressing abrasion inside the transport pipe.

Further, since the tip portion 107A of the heat exchange tube 107 has a trumpet shape, the foundry sand S positioned near the bottom of the heat exchange tube 107 can be sent into the heat exchange tube 107 more efficiently. . That is, the transport efficiency of the foundry sand S in the heat exchange tube 107 can be improved. In addition, since the upper end of the tip portion of the compressed air supply pipe 106 is located above the lower end of the tip portion 107A of the heat exchange pipe 107, the air flows toward the inside of the heat exchange pipe 107 via the compressed air supply pipe 106. The foundry sand S can be sent into the heat exchange tube 107 more reliably by the compressed air supplied through the heat exchange tube 107 .

Further, in the lower heat exchange tank 101, the supply port 101A is provided so as to be inclined upward from the upper side of the side surface of the lower heat exchange tank 101 as the distance from the side surface increases. That is, the supply port 101A serves as a free-falling chute. Therefore, the foundry sand S collected from the previous step can be supplied into the lower heat exchange tank 101 without using a conveying device such as a bucket elevator.
Similarly, in the upper heat exchange tank 108, the discharge port 108A is provided from the lower side of the side surface of the upper heat exchange tank 108 so as to incline downward as the distance from the side surface increases. That is, the discharge port 108A is a free-falling chute. Therefore, the foundry sand S inside the upper heat exchange tank 108 can be supplied to the subsequent process without using a conveying device such as a bucket elevator.

Further, when the molding sand S is transported by a suction type dust collector, a large amount of air is required for the amount of the molding sand S to be transported, and a large fan is required. Therefore, it is necessary to increase the size of the filter of the suction dust collector. Further, since the fine dust and additives contained in the foundry sand S clog the filter of the suction dust collector, the filter needs to be cleaned. However, in the heat exchange device 100 according to Embodiment 1, since compressed air is used to transport the foundry sand S in the heat exchange tubes 107, neither a large filter nor a large fan is required, and cleaning of the filter is not necessary.

Further, in the heat exchange device 100 according to Embodiment 1, it is not necessary to use cooling water for cooling the foundry sand S. Therefore, a radiator and thin pipes for heat exchange can be omitted.

It should be noted that the present invention is not limited to the above embodiments, and can be modified as appropriate without departing from the scope of the invention. For example, the heights of the partition plates 102A, 102B, and 102C are appropriately set in accordance with the characteristics of the material for heat exchange and the heat exchange specifications, and are not limited to those shown in the first embodiment. Absent. Thereby, the retention time of the molding sand S in each heat exchange zone of the lower heat exchange tank 101 partitioned by the partition plates 102A, 102B, and 102C can be set according to the material properties of the molding sand S and the desired heat exchange specifications. can be done. Similarly, by appropriately setting the heights of the partition plates 109A, 109B, and 109C in accordance with the characteristics of the materials to be heat-exchanged and the heat exchange specifications, the upper heat exchange tanks partitioned by the partition plates 109A, 109B, and 109C The residence time of the foundry sand S in each heat exchange zone 108 can be set to a desired time.

100 Heat exchange device 101 Lower heat exchange tank 101A Supply ports 102A, 102B, 102C Partition plate 103 Lower fluidized air box 104 Lower perforated plate 105 Lower fluidized air supply pipe 106 Compressed air supply pipe (compressed air supply unit)
107 Heat exchange tube 108 Upper heat exchange tanks 109A, 109B, 109C Partition plate 110 Upper fluidized air box 111 Upper perforated plate 112 Upper fluidized air supply pipe Z1 Lower heat exchange zone Z2 Transportation heat exchange zone Z3 Upper heat exchange zone S Foundry sand

Claims (1)

A heat source provided with a supply port for supplying molding sand, supplied with flowing air having a temperature different from that of the molding sand from the lower portion, and having a plurality of standing partition plates whose height decreases as the distance from the supply port increases. an exchange tank;
A pipe erected along the vertical direction of the heat exchange tank at a position opposite to the supply port side of the heat exchange tank, the lower part of the pipe being inserted into the heat exchange tank. a heat exchange tube with
Compressed air having a temperature different from that of the foundry sand is supplied from the lower side of the heat exchange tube toward the upper end of the heat exchange tube to remove the foundry sand located near the lower end of the heat exchange tube. a compressed air supply to the upper end of the heat exchange tube ;
with
A heat exchange device for molding sand , wherein an upper end of a tip portion of the compressed air supply portion that supplies compressed air is located above the lower end portion of the heat exchange tube .

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