JP5038193B2 - Magnetic foreign matter removal device - Google Patents

Description

  The present invention relates to a magnetic foreign matter removing apparatus that removes magnetic foreign matter mixed in an oil-containing powder granule such as cacao powder or chicken powder from an oil-containing powder granule.

  Oil and fat-containing granules such as cacao powder and chicken powder may contain magnetic foreign substances such as iron pieces, iron oxide-containing pebbles, and iron oxide-containing soil during the manufacturing process of oil-and-fat-containing granules. As a device to remove foreign matter, a magnet is placed in a rotating drum that rotates about a substantially horizontal axis, and magnetic foreign matter and oil / fat adhering to the surface of the oil / fat-containing powder particles by the magnetic attraction force of this magnet 2. Description of the Related Art A magnetic foreign matter removing device is known that separates and removes magnetic foreign matters (hereinafter collectively referred to as “magnetic foreign matters”) contained in the contained granular materials from the oil and fat containing granular materials (see Patent Document 1). ).

Such a magnetic foreign matter removing apparatus is a permanent magnet comprising a transport belt for transporting resin pellets, a drive roll and a magnet roll for winding the transport belt, and a separating scraper disposed in the vicinity of the magnet roll. Like a roll separator (see, for example, Patent Document 2), the conveyor belt adjusts the meandering and tension of the conveyor belt, or removes magnetic foreign material-contaminated pellets adhered to the surface of the conveyor belt by the magnetic attraction force of the permanent magnet roll. There is an advantage that it is not necessary to provide a separating scraper to be scraped off from the surface.
Japanese Patent Laying-Open No. 2004-9005 (paragraphs 0019 to 0022, FIG. 1) JP-A-4-74546

However, when the surface temperature of the rotating drum becomes higher than the oil / fat liquefaction temperature of the oil / fat-containing powder, a part of the oil / fat of the oil / fat-containing powder dropped on the rotating drum is liquefied. As shown in FIG. 3 (b), the oil-and-fat-containing powder granules S are initially partially adhered to the surface (circumferential surface) of the rotating drum 2, but finally, as shown in FIG. The granular material S adheres to the entire surface (the entire peripheral surface) of the rotating drum 2. For this reason, the magnetic attraction force of the magnet 8 disposed inside the rotating drum 2 becomes difficult to act on the magnetic foreign matter, and the removal efficiency of the magnetic foreign matter may be reduced.
The present invention has been made paying attention to the above-mentioned problems, and provides a magnetic foreign matter removing apparatus capable of preventing a reduction in the efficiency of removing magnetic foreign matters due to the adhesion of oil and fat-containing powder particles to the surface of a rotating drum. The purpose is to do.

In order to solve the above-mentioned problems, a first aspect of the present invention is a rotating drum that rotates about a substantially horizontal axis, and a powder dropping mechanism that drops oil-containing powder on the outer peripheral surface of the rotating drum. And a magnet disposed inside the rotating drum, and the magnetic foreign matter mixed in the oil-containing powder particles is separated from the oil-containing powder particles by the magnetic attraction force of the magnet and removed. In the removing apparatus, a drum cooling means is provided for supplying a cooling gas to the inside of the rotary drum to cool the outer peripheral surface of the rotary drum to a temperature lower than the oil / fat liquefaction temperature of the oil / fat-containing powder. to.

Invention of Claim 2 is the magnetic foreign material removal apparatus of Claim 1 , Comprising: The said rotating drum has a cylindrical part, a pair of end plate part which obstruct | occludes the both-ends opening part of this cylindrical part, These end plate part A rotating shaft extending in the axial direction of the rotating drum from a central portion of the outer surface of the rotating drum, and a shaft portion through which the magnet penetrates in the rotating shaft of the rotating drum or the end plate in the axial direction of the rotating drum It is characterized by having.
According to a third aspect of the invention, a magnetic foreign matter removing apparatus according to claim 2, the cooling portion in which the drum cooling means to cool the cooling gas to a temperature lower than the oil and fat liquefaction temperature of the fat-containing powder and granular material And a gas supply pipe for supplying the cooling gas cooled to a predetermined temperature by the cooling unit to the inside of the rotary drum from an air supply path formed in the shaft part of the magnet.

According to a fourth aspect of the present invention, there is provided the magnetic foreign matter removing device according to the third aspect , wherein the drum cooling means has an exhaust passage formed in the shaft portion of the magnet by the cooling gas supplied into the rotary drum. It has the gas recovery pipe | tube which collect | recovers from and returns to the said cooling part, It is characterized by the above-mentioned.
Invention of Claim 5 is a magnetic foreign material removal apparatus as described in any one of Claims 1-4 , Comprising: The said granular material dropping mechanism conveys the said oil-and-fat content granular material above the said rotating drum. It has a granular material feeder and the granular material cooling mechanism part which cools the fat and oil containing granular material conveyed by this granular material feeder, It is characterized by the above-mentioned.

  According to the magnetic foreign matter removing apparatus of the first aspect of the present invention, when the rotating drum is cooled to a temperature lower than the oil / fat liquefaction temperature of the oil / fat-containing particles by the drum cooling means, the oil / fat content of the oil / fat-containing particles Becomes difficult to liquefy on the surface of the rotating drum. Therefore, it becomes difficult for oil-and-fat-containing powder particles to adhere to the surface of the rotating drum, and it is possible to prevent a reduction in magnetic foreign matter removal efficiency due to the oil-and-fat-containing powder particles adhering to the surface of the rotating drum.

Further , since the cooling drum is cooled by supplying a cooling gas to the inside of the rotating drum, for example, when the rotating drum is cooled by blowing the cooling gas to the outer surface of the rotating drum, the oil-containing powder The particles are not scattered, and the magnetic foreign matter separated from the oil-containing powder particles by the magnetic attraction action of the magnet is not mixed into the oil-containing powder particles again. Accordingly, it is possible to prevent a reduction in the removal efficiency of the magnetic foreign matter without incurring scattering of the oil-and-fat-containing powder or re-mixing of the magnetic foreign matter.
According to the magnetic foreign matter removing apparatus according to the fifth aspect of the present invention, the oil-containing powder granules conveyed to the upper position of the rotary drum by the powder feeder are cooled by the powder cooling mechanism and then placed on the rotary drum. Since it is dropped, it is possible to more effectively prevent a reduction in the efficiency of removing magnetic foreign substances due to the adhesion of oil-and-fat-containing powder particles to the surface of the rotating drum.

  FIG. 1 shows a schematic configuration of the magnetic foreign matter removing apparatus according to the first embodiment of the present invention. As shown in the figure, the magnetic foreign matter removing apparatus 1 according to the first embodiment of the present invention includes a rotating drum 2 that rotates clockwise about a substantially horizontal axis in the drawing. The oil-and-fat-containing granular material such as cacao powder is dropped from the granular material dropping mechanism 3 disposed above the rotary drum 2.

The granular material dropping mechanism 3 includes a hopper 4 and a vibration feeder 5 as a granular material feeder for conveying the oil-containing powder granular material charged into the hopper 4 to the upper side of the rotary drum 2. The oil-and-fat-containing powder particles conveyed above the rotating drum 2 by 5 are dropped onto the rotating drum 2 from the rectifying chute 6.
The vibration feeder 5 has a trough 5 a that receives the oil-fat-containing powder particles put into the hopper 4. This trough 5a has a jacket structure, and in the trough 5a of the vibration feeder 5, in order to cool the oil-containing powder particles on the trough 5a, a powder cooling fluid such as air or water is powdered. It is supplied from the object cooling mechanism 7.

  The inside of the rotating drum 2 has a hollow structure, and the magnet 8 is arranged in the inside of the rotating drum 2 so that a magnetic attraction force acts on the magnetic foreign matter mixed in the oil-containing powder particles. Yes. The rotating drum 2 is housed in a sorting case 9 of the magnetic foreign matter removing apparatus 1, and the oil-containing powder particles discharged from the rotating drum 2 and the magnetic foreign matter are separated in the sorting case 9. A separation plate 10 is provided, and a separation plate support shaft 11 that supports the separation plate 10 so as to be tiltable with respect to the rotary drum 2 is provided.

  The sorting case 9 has a magnetic foreign substance (for example, a magnetic foreign substance alone, an oil / fat containing granular substance with a magnetic foreign substance adhering to the surface thereof, or a magnetic foreign substance entering the inside, separated from the oil-containing granular substance by the separation plate 10. It has a defective product chute 9a for dropping the oil and fat-containing granule into a defective product receiver (not shown) as a defective product. The sorting case 9 has a non-defective product chute 9b for dropping a non-defective product (oil-and-fat-containing particulate matter not containing magnetic foreign matter) onto the non-defective product receiver 12. Between the receptacle 12 and the like, for example, a non-magnetic metal foreign object such as an aluminum metal piece (for example, a non-magnetic metal foreign substance alone, oil-and-fat-containing granular material with a non-magnetic metal foreign substance adhering to the surface, and a non-magnetic metal foreign substance are inside. A non-magnetic metal foreign matter separating mechanism 13 is provided for separating the oil-containing powder particles) from the oil-containing powder particles.

  The nonmagnetic metal foreign matter separation mechanism 13 has a metal detector 13a that detects nonmagnetic metal foreign matter mixed in the oil-and-fat-containing powder. Further, the nonmagnetic metal foreign matter separation mechanism 13 has a separation plate 13b for separating the nonmagnetic metal foreign matter detected by the metal detector 13a from the oil-containing powder particles, and the oil-containing powder particles are separated by this separation plate 13b. The non-magnetic metal foreign matter separated from the gas is discharged to the defective product receiver 14 through the defective product discharge path 13c. In addition, the oil-and-fat containing granular material separated from the nonmagnetic metal foreign matter by the separation plate 13b is discharged to the non-defective product receiver 12 through the non-defective product discharge path 13d.

  A cross section along the axial direction of the rotating drum 2 is shown in FIG. As shown in the figure, the rotary drum 2 closes a thin-walled cylindrical portion 2a (for example, a thickness of 1 mm or less) made of a non-magnetic material (for example, stainless steel such as SUS304), and openings at both ends of the cylindrical portion 2a. It has a pair of end plate parts 2b and 2c. The rotary drum 2 has hollow rotary shafts 2d and 2e extending in the axial direction of the rotary drum 2 from the center of the outer surface of the end plate portions 2b and 2c. Each is supported rotatably by a bearing 15. The rotary drum 2 is a drum drive composed of, for example, a pulley 16a mounted on the rotary shaft 2e of the rotary drum 2 and a geared motor 16d as a drive motor for driving the pulley 16a via a drive belt 16b and a pulley 16c. The mechanism 16 is rotationally driven.

The magnet 8 has a shaft portion 8a (see FIG. 2) that penetrates the rotating shafts 2d and 2e of the rotating drum 2 in the axial direction of the rotating drum 2, and a roll-shaped magnet main body 8b is provided on the shaft portion 8a. Is retained. The magnet body 8b does not necessarily have a roll shape. Moreover, it is preferable that the magnetic force of the magnet main body 8b is 14000 Gauss or more, for example.
Inside the rotary drum 2, a drum cooling mechanism 17 (see FIG. 2) that cools the rotary drum 2 to a temperature lower than the oil / fat liquefaction temperature of the oil / fat-containing granular material (for example, about 5 ° C. lower than the oil / fat liquefaction temperature). A cooling gas (for example, air) is supplied.

  The drum cooling mechanism 17 has a cooling unit 17a that cools the cooling gas to a temperature lower than the oil / fat liquefaction temperature of the oil / fat-containing granular material. The drum cooling mechanism 17 includes a gas supply pipe 17b that supplies the cooling gas cooled to a predetermined temperature by the cooling unit 17a to the inside of the rotary drum 2 from an air supply path 8c formed in the shaft 8a of the magnet 8. A cooling gas supplied to the inside of the rotating drum 2 is recovered from an exhaust passage 8d formed in the shaft portion 8a of the magnet 8 and returned to the cooling portion 17a. The returned cooling gas is cooled to a predetermined temperature and then supplied to the gas supply pipe 17b by the blower 17d.

In FIG. 2, reference numeral 18 denotes an airtight seal that hermetically seals a gap between the hollow rotary shafts 2 d and 2 e of the rotary drum 2 and the shaft portion 8 a of the magnet 8.
When the rotating drum 2 is cooled to a temperature lower than the oil / fat liquefaction temperature of the oil / fat-containing powder / granule by the drum cooling mechanism 17 as in the first embodiment of the present invention shown in FIG. 1 and FIG. It becomes difficult for the oil and fat content to be liquefied on the surface of the rotary drum 2. Therefore, it becomes difficult for oil-and-fat-containing powder particles to adhere to the surface of the rotating drum 2, and it is possible to prevent a reduction in the efficiency of removing magnetic foreign substances due to the oil-and-fat-containing particles adhering to the surface of the rotating drum 2.

  In addition, when the rotating drum 2 is cooled by blowing a cooling gas to the outer surface of the rotating drum 2, the oil-containing powder particles are scattered or separated from the oil-containing powder particles by the magnetic attraction action of the magnet 8. However, in the first embodiment of the present invention shown in FIGS. 1 and 2, a cooling gas is supplied to the inside of the rotary drum 2. Since the rotating drum 2 is cooled, it is possible to prevent a reduction in the removal efficiency of the magnetic foreign matter without causing scattering of the oil-and-fat-containing powder or re-mixing of the magnetic foreign matter.

  Furthermore, in 1st Embodiment of this invention shown in FIG.1 and FIG.2, the fat and oil containing granular material which fell on the vibration feeder 5 is supplied in the trough 5a of the vibration feeder 5 from the granular material cooling mechanism part 7. FIG. Since it is dropped on the rotating drum 2 after being cooled by the fluid for cooling the granular material, it is more effectively prevented that the efficiency of removing magnetic foreign matters due to the adhesion of the oil / fat containing granular material on the surface of the rotating drum 2 is prevented. can do.

In the first embodiment of the present invention shown in FIGS. 1 and 2, the magnet 8 is also cooled by the cooling gas supplied to the inside of the rotary drum 2, so that the magnetic attraction force of the magnet 8 increases in temperature. It can prevent that it falls by.
When the surface of the rotating drum was cooled to 20 ° C. in an atmosphere of room temperature 29-30 ° C. and relative humidity 30%, chicken powder (oil fat liquefaction temperature: 25 ° C.) was dropped on the rotating drum in this state. The experimental result that the adhesion of the chicken powder to the drum surface was not seen was obtained. In addition, when the surface of the rotating drum was cooled to 21-22 ° C in an atmosphere of room temperature 28 ° C and relative humidity 30%, cocoa powder (oil liquefaction temperature: 26-27 ° C) was dropped on the rotating drum in this state. An experimental result was obtained that no cacao powder adhered to the surface of the rotating drum.

  In the first embodiment of the present invention shown in FIGS. 1 and 2, the magnetic foreign matter removing apparatus in which the shaft portion 8 a of the magnet 8 penetrates the rotating shafts 2 d and 2 e of the rotating drum 2 in the axial direction of the rotating drum 2. Although the case where the present invention is applied is shown, the present invention is not limited to this. For example, the present invention can be applied to a magnetic foreign matter removing device in which the shaft portion 8 a of the magnet 8 passes through the end plate portions 2 b and 2 c of the rotating drum 2 in the axial direction of the rotating drum 2.

  Moreover, in 1st Embodiment of this invention shown in FIG.1 and FIG.2, as a drum cooling means which cools a rotating drum to the temperature lower than the fat and oil liquefaction temperature of fat and oil containing granule, cooling gas is oil and fat containing powder. A cooling unit 17a for cooling to a temperature lower than the oil / fat liquefaction temperature of the granule, and a cooling gas cooled by the cooling unit 17a to a predetermined temperature from an air supply path 8c formed in the shaft 8a of the magnet 8 The gas supply pipe 17b supplied to the inside of the rotary drum 2 and the gas recovery pipe for recovering the cooling gas supplied to the inside of the rotary drum 2 from the exhaust passage 8d formed in the shaft portion 8a of the magnet 8 and returning it to the cooling portion 17a Although the drum cooling mechanism 17 consisting of 17c is shown, it is not limited to this. For example, a cooling unit that cools the cooling gas to a temperature lower than the oil / fat liquefaction temperature of the oil / fat-containing granule, and a gas supply pipe that supplies the cooling gas cooled to a predetermined temperature by the cooling unit to the inside of the rotary drum A drum cooling mechanism consisting of:

It is a figure which shows schematic structure of the magnetic foreign material removal apparatus which concerns on 1st Embodiment of this invention. It is a figure which shows the principal part of the magnetic foreign material removal apparatus which concerns on 1st Embodiment of this invention. It is a figure for demonstrating the problem of the conventional magnetic foreign material removal apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Magnetic foreign material removal apparatus 2 Rotating drum 2a Cylindrical part 2b, 2c End plate part 2d, 2e Rotating shaft 3 Powder drop mechanism 4 Hopper 5 Vibrating feeder 6 Rectification chute 7 Powder particle cooling mechanism part 8 Magnet 8a Shaft part 8b Magnet Main body 8c Air supply path 8d Exhaust path 9 Sorting case 9a Defective product chute 9b Non-defective chute 10 Separating plate 11 Separating plate support shaft 12 Non-defective metal receiving 13 Nonmagnetic metal foreign matter separating mechanism 13a Metal detector 13b Separating plate 13c Defective product discharging path 14 Defective product receiver 15 Bearing 16 Drum drive mechanism 17 Drum cooling mechanism 17a Cooling unit 17b Gas supply pipe 17c Gas recovery pipe 18 Airtight seal

Claims (5)

A rotating drum that rotates about a substantially horizontal axis, a powder dropping mechanism that drops oil-containing powder on the outer peripheral surface of the rotating drum, and a magnet disposed inside the rotating drum. In the magnetic foreign matter removing device for separating and removing the magnetic foreign matter mixed in the oil-containing powder particles from the oil-containing powder particles by the magnetic attraction force of the magnet , a cooling gas is supplied to the inside of the rotating drum. A magnetic foreign matter removing apparatus is provided with drum cooling means for cooling the outer circumferential surface of the rotating drum to a temperature lower than the oil / fat liquefaction temperature of the oil / fat-containing powder. The magnetic foreign matter removing apparatus according to claim 1 , wherein the rotating drum is a cylindrical portion, a pair of end plate portions that close both end openings of the cylindrical portion, and the rotation from the center portion of the outer surface of the end plate portions. And a magnet having a shaft portion that passes through the rotation shaft or end plate of the rotation drum in the axial direction of the rotation drum. Foreign matter removal device. 3. The magnetic foreign matter removing apparatus according to claim 2 , wherein the drum cooling means cools the cooling gas to a temperature lower than an oil / fat liquefaction temperature of the oil / fat-containing granular material, and a predetermined temperature at the cooling unit. And a gas supply pipe for supplying the cooling gas cooled to the inside of the rotary drum from an air supply path formed in the shaft portion of the magnet. 4. The magnetic foreign matter removing apparatus according to claim 3 , wherein the drum cooling means collects the cooling gas supplied to the inside of the rotating drum from an exhaust passage formed in a shaft portion of the magnet and supplies the cooling gas to the cooling portion. A magnetic foreign matter removing apparatus having a gas recovery pipe for returning. It is a magnetic foreign material removal apparatus as described in any one of Claims 1-4 , Comprising: The granular material feeder which the said granular material dropping mechanism conveys the said fat-and-oil content granular material above the said rotating drum, This powder A magnetic foreign matter removing apparatus comprising: a powder and particle cooling mechanism for cooling the oil and fat-containing powder and particles conveyed by the particle feeder.

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