JP2011218270A - Powder cooling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of dew condensation on the inner wall surface of an agitation tank when cooling the powder of a food raw material to prevent the lump of powders caused by dew condensation from intruding.SOLUTION: There is provided a powder cooling device including: an agitation tank 4 having a powder charging port 5 on the upper part of the tank and a powder discharge port 8 on the lower part thereof; the agitation blades 22 and 24 which are disposed rotatably in the agitation tank to agitate the powder of the food raw material in the tank; a cooling liquid flow path 10 which is provided in a tank wall so that the lower area of the inner wall surface of the agitation tank becomes a cooling face; and a heating member 12 which is provided in a tank wall so that the upper area of the inner wall surface of the tank becomes a heating face.

Description

  The present invention relates to a powder cooling apparatus for cooling a food raw material powder such as wheat flour for confectionery while stirring.

  When food raw material powder such as wheat flour is stored in an outdoor silo and the food raw material powder is transported from the silo or the like into the food factory with compressed air, the temperature of the food raw material powder rises to about 40 ° C. There is a case. Therefore, when food raw material powder is used for confectionery, for example, it is necessary to cool the temperature of the food raw material powder to about 15 to 25 ° C. in order to make a high-quality dough. Therefore, a powder temperature adjusting device for cooling the food raw material powder while stirring has been proposed. In this apparatus, a flow path for cooling liquid or the like is formed on the outer periphery of the stirring tank, and the cooling liquid is circulated in the flow path to cool the powder in the stirring tank and to rotate in the stirring tank. The raw material powder is stirred to increase the cooling efficiency (see Patent Document 1).

Japanese Patent Publication No. 7-71441

  However, in this powder temperature control device, dew condensation may occur on the upper inner wall surface of the agitation tank. In some cases, a lump of powder was mixed in the body. Moreover, the lump may adhere to the inner wall surface of the upper part of the stirring tank, resulting in an undesirable state.

  An object of the present invention is to provide a powder cooling apparatus capable of preventing the formation of condensation on the inner wall surface of a stirring tank when cooling a raw material powder and preventing the mixing of powder lump due to the condensation. That is.

  The powder cooling device of the present invention includes a stirring tank having a powder inlet at the top and a powder outlet at the bottom, and a food material in the stirring tank that is rotatably disposed in the stirring tank. A stirring blade for stirring the powder, a coolant flow path provided in the tank wall so that a lower area of the inner wall surface of the stirring tank serves as a cooling surface, and an upper area of the inner wall surface of the tank is heated. And a heating member provided in the tank wall so as to be a surface.

  In the powder cooling device of the present invention, the heating member includes a heater.

  In the powder cooling device of the present invention, the heating member includes a heating liquid channel.

  In addition, the powder cooling device of the present invention includes a heat blocking member between the cooling surface and the heating surface.

  In addition, the powder cooling device of the present invention includes a dehumidified compressed air supply unit that supplies dehumidified compressed air to the agitation tank.

  ADVANTAGE OF THE INVENTION According to this invention, when food raw material powder is cooled, it can prevent that condensation forms on the inner wall face of a stirring tank, and can prevent mixing of the lump of the powder by condensation.

It is sectional drawing which looked at the powder cooling device concerning an embodiment from the side. It is sectional drawing in the position containing the powder inlet and the powder outlet of the stirring tank which concerns on embodiment. It is a figure for demonstrating cooling of the powder by the powder cooling device which concerns on embodiment.

  Hereinafter, a powder cooling apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a powder cooling device according to an embodiment of the present invention as viewed from the side, and FIG. 2 is a cross-sectional view at a position including a powder inlet and a powder outlet of a stirring tank.

  As shown in FIG.1 and FIG.2, the powder cooling device 2 is equipped with the stirring tank 4 which has a U-shaped cross section and has a flat upper plate in the upper part. The upper plate of the agitation tank 4 is supplied from a powder inlet 5 into which the raw material powder is introduced, a bag filter 6 for removing air from the agitation tank 4 and a compressor 34 (see FIG. 3) described later. A supply port 7 for dehumidified compressed air is provided. A discharge port 8 for discharging the food raw material powder in the stirring tank 4 is provided at the lower part of the stirring tank 4.

  A cooling liquid channel 10 is provided in the tank wall where the lower section of the stirring tank 4 is semicircular, and the inner wall surface of the tank in the region where the cooling liquid channel 10 is provided serves as a cooling surface. Function. The cooling liquid is supplied into the cooling liquid flow path 10 from a cooling liquid inlet (not shown) provided in the lower part of the stirring tank 4, circulated in the cooling liquid flow path 10, and then provided in the lower part of the stirring tank 4. It is discharged from a coolant outlet (not shown). In addition, a heater 12 is provided in the tank wall where the tank wall at the top of the stirring tank 4 is a straight portion, and the inner wall surface of the tank where the heater 12 is provided functions as a heating surface.

  A heat insulating material 14 formed of glass wool or urethane is arranged outside the portion where the coolant flow path 10 is provided in the tank wall of the stirring vessel 4 and the portion where the heater 12 is provided. A heat blocking member 16 is disposed between a portion where the coolant flow path 10 is provided in the tank wall and a portion where the heater 12 is provided.

  Bearings 18 and 18 are installed at both ends of the agitation tank 4, and the rotating shaft 20 is supported by the bearings 18 and 18. In the stirring tank 4, two large and small ribbon-shaped first stirring blades 22 and second stirring blades 24 fixed to the rotary shaft 20 are accommodated. Here, the outer first agitating blade 22 and the inner second agitating blade 24 have opposite spiral twist directions, and when the rotary shaft 20 rotates in a certain direction, In the vicinity of the outer periphery, the food raw material powder moves in the opposite directions to increase the stirring efficiency.

  At a predetermined position of the first stirring blade 22, a rod-shaped powder scraping member 26 that rotates along the immediate vicinity of the cooling surface of the stirring tank 4 is attached. Here, the powder scraping member 26 is installed at four locations at intervals of 90 ° in the circumferential direction of the first stirring blade 22.

  In the powder cooling device 2 according to the present embodiment, when cooling wheat flour, which is a food raw material powder for confectionery, the air dried by the air dryer 28 is compressed by the blower 30 as shown in FIG. Then, the wheat flour stored in the outdoor silo 32 is pneumatically transported to the powder inlet 5 of the powder cooling device 2 installed indoors by compressed air, and the flour is stirred from the powder inlet 5 to the stirring tank 4. In. Flour is mixed into the agitation tank 4 in a mixed state with air for transportation, but only air is discharged to the outside from the bag filter 6 installed at the top of the agitation tank 4, and the powder is stored in the agitation tank 4. Is done.

  A coolant cooled to −5 ° C. is continuously supplied and circulated in the coolant channel 10 of the powder cooling device 2. Thereby, the cooling surface of the stirring tank 4 is cooled. On the other hand, the heating surface of the stirring tank 4 is heated to 40-60 ° C. by the heater 12.

  The flour in the agitation tank 4 is agitated by the agitation blades 22 and 24 that are rotated when the rotary shaft 20 is rotationally driven by a motor (not shown), and is efficiently brought into contact with the cooling surface of the agitation tank 4 and cooled. Further, the powder scraping member 26 attached to the first stirring blade 22 moves along the vicinity of the cooling surface as the stirring blade 22 rotates, so that the flour layer adhering to the cooling surface is scraped off. The cooling of the flour is efficiently performed by preventing the cooling efficiency from decreasing on the surface. Further, dehumidified compressed air is continuously supplied into the stirring tank 4 from the compressor 34 through the supply port 7 during the cooling period of the flour. Since the temperature of the dehumidified compressed air supplied from the supply port 7 into the agitation tank 4 is adiabatically expanded when it is opened to the atmosphere, cooling of the flour is further promoted. Moreover, the humidity contained in wheat flour can be reduced by the dehumidified compressed air supplied from the supply port 7. The dehumidified compressed air supplied into the agitation tank 4 is discharged from the bag filter 6.

  Here, in the powder cooling device 2, since the heat blocking member 16 is disposed between the cooling surface and the heating surface of the stirring tank 4, the upper region of the inner wall surface of the stirring tank 4 is the coolant channel. 10 can be prevented from being cooled by the coolant circulating in the interior 10, and the heating surface of the upper region of the inner wall surface of the stirring tank 4 is heated by the heater 12. It is possible to prevent dew condensation from occurring in the upper region. Therefore, when the wheat flour is cooled, it is possible to prevent the wheat flour that has come into contact with dew from becoming a lump and mixing it with the wheat flour stored in the stirring tank 4. Moreover, it is possible to prevent the lump from adhering to the upper inner wall surface of the stirring tank. The wheat flour thus cooled is taken out from the powder outlet 8 and collected.

  In the above-described embodiment, the heater 12 is used to form a heating surface on the inner wall surface of the agitation tank 4, but a hot water flow path for circulating hot water of 40 to 60 ° C. in the tank wall. The heating surface of the provided stirring tank 4 may be heated.

  Further, in the above-described embodiment, the powder scraping member 26 is installed at four positions at 90 ° intervals in the circumferential direction of the first stirring blade 22, but in the circumferential direction of the first stirring blade 22. Three locations may be installed at 120 ° intervals, and the number and installation intervals of the powder scraping member 26 may be appropriately changed.

  Moreover, the temperature of the coolant supplied into the coolant flow path 10 of the powder cooling device 2 is not limited to −5 ° C., and may be changed as appropriate.

DESCRIPTION OF SYMBOLS 2 ... Powder cooling device, 4 ... Agitation tank, 5 ... Powder inlet, 6 ... Bag filter, 8 ... Powder discharge port, 10 ... Coolant flow dew, 12 ... Heater, 16 ... Heat insulation member, 22nd 1 stirring blade, 24 ... 2nd stirring blade

Claims (5)

A stirring tank provided with a powder inlet at the top and a powder outlet at the bottom;
A stirring blade that is rotatably arranged in the stirring tank and stirs the food raw material powder in the stirring tank;
A coolant flow path provided in the tank wall so that a lower region of the inner wall surface of the stirring tank serves as a cooling surface;
A heating member provided in the tank wall so that the upper region of the inner wall surface of the tank is a heating surface;
A powder cooling device comprising:   The powder cooling apparatus according to claim 1, wherein the heating member includes a heater.   The powder cooling apparatus according to claim 1, wherein the heating member includes a heating liquid channel.   The powder cooling device according to any one of claims 1 to 3, further comprising a heat blocking member between the cooling surface and the heating surface.   The powder cooling apparatus according to claim 1, further comprising a dehumidified compressed air supply unit that supplies dehumidified compressed air to the stirring tank.

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