JPH01130710A - Powder separation device and powder treating unit - Google Patents

Abstract

PURPOSE:To efficiently collect powder while preventing the powder from crushing by confronting a powder mixing gas inlet pipe having an opening part against a powder collecting part with a clearance of specified space distance between, and discharging a part of gas from the gas discharge opening of separation chamber. CONSTITUTION:The powder mixing gas introduced to the powder mixing gas inlet pipe 2 is vertically flowed and accelerated at the bottom part 12 according to the ratio of the diameter (d) of the opening part 13 to the diameter D1 of the gas inlet pipe 2. The gaseous part of the powder mixing gas blowing out from the opening part 13 is taken out at the clearance part 15 with a certain angle to the vertical direction into the inside of the separation chamber 1, and is discharged from the gas discharge opening 4 with a discharging gas quantity l0. On the other hand, the powder is flowed with the gas as far as the opening part 13, and then straightly moved by the inertia and the gravity force into the powder collecting part 3 through a powder taking-in opening 14. The quantity of the gas flowing the powder collecting part is only the quantity discharged from a gas extraction opening 5 so that the powder is precipitated with the terminal precipitation velocity and collected while being prevented from crushing. The lowering of collecting capacity is eliminated by adjusting the gas discharge quantity l1 discharged from the gas extraction opening 5 and the gas discharge quantity l0.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention separates powder and gas from powder containing gas such as air, especially edible powder, by utilizing linear inertia force, and produces powder in a stable state. A powder separation device for obtaining aggregates, which prevents the powder from rubbing against the inner wall of the device and eliminates gas without colliding with the inner wall and destroying the porosity of the powder particles. It is related to the device.

Furthermore, the present invention arranges a powder separator that separates powder and gas in the downstream process of an air-mixing powder pumping device or a powder manufacturing machine, and collects most of the sent powder. This invention relates to a powder processing unit in which a collection device with a high collection rate, such as a cyclone collector, is connected to the next step.

[Conventional technology]

Cyclone collectors that utilize centrifugal force and bag filters that perform filtration and separation are known as devices that have already been put into practical use as collection devices for edible powders such as powdered milk and instant coffee.

In the process of manufacturing powder from liquid raw materials, a powder manufacturing machine such as a spray dryer is used, which atomizes the concentrated raw material and dries it while mixing it with dry hot air. In order to separate and collect the powder, a unit incorporating the cyclone collector or back filter has conventionally been used between the powder manufacturing machine and the air outlet.

In addition, an air mixed powder conveying device (pneumatic conveyor) is used to continuously convey the obtained powder to another location.
The same applies to gas separation in ).

On the other hand, in fields other than edible powders, various devices have been developed and put into practical use, such as the collision type 1 reversal type and the looper 2, which utilize inertia for the purpose of transporting fine inorganic powders or collecting dust. ing.

Here, among these papers, I would like to present and explain the outline of a paper that is considered to be close to the present invention.
, No. 4 (197B)) is a theoretical study of the influence of straight flow rate, slit interval, fluid viscosity, and classification tube wall thickness on the classification performance of the virtual invactor, which is a conventionally known classification experimental device. This is a report on the results of the study. The experimental apparatus has the structure shown in FIG.
103 were installed vertically facing each other, circumferential slits 104 were provided on the cut surfaces of both opposing circular tubes, and aerosolized methylene blue/uranine fine particles were supplied from above, with a straight flow rate ratio of approximately 1/1O. This is the result of determining the classification efficiency at the time.

In this experimental device, when the aerosol is ejected from the upper circular pipe 102 and sucked into the lower circular pipe 103, coarse particles with a strong inertial force are suctioned into the lower circular pipe 103, and fine particles with a weak inertial force are transferred to the lower circular pipe 103. The particles flow out laterally from the slit portion 104 and move to the chamber lower part 105, allowing both particle groups to be classified. In this experimental apparatus, the aerosolized methylene blue/uranine fine particles are supplied using an aerosol generator 106 and a mixer 107, and the lower circular tube 103 is supplied with a filter 108. meter 10
9 to a vacuum pump 110, and a flow meter 1 is connected to the chamber lower part 105 via a filter 111.
12 and a prower 113 are connected.

In addition, if we present other similar prior art,
- Technology for a powder separator in which the separation rate can be adjusted by advancing and retracting the collision plate as described in Japanese Patent Publication No. 21493; Technology for a separation device that prevents agglomeration of particles to be separated and performs effective separation by configuring a device consisting of a unit formed by a space made up of a contraction part, Japanese Patent Publication No. 60-3680
The louver type described in Publication No. 8 has a baffle that is rotatably arranged so as to change the projected area of the plate-shaped panful with respect to the airflow, and has a simple structure that performs optimal dust collection according to the gas condition. There are technologies for dust collectors, etc.

[Problem that the invention seeks to solve]

Milk powder, which is an edible powder, has the following properties unlike powder such as boat dust. In other words, milk powder is
It contains many components such as protein, fat, lactose, and inorganic components, and when viewed as a particle, it is not a single particle but approximately 20~
Several single grains of about 30μ exist in a bonded state.

The particles have many voids between them, making them relatively susceptible to external forces. Therefore, it is likely to be crushed by collision with the inner wall of the processing device or by friction (and as it becomes atomized, it becomes a cause of a decrease in its affinity with water (easiness to dissolve).

In particular, the fat contained in the powdered milk particles is wrapped in a protein protective film, forming a spherical shape of 1 to 3 microns, and is almost evenly dispersed, and the protective film of the fat globules collides with the inner wall of the device. Alternatively, when individual fat globules are destroyed by an external force such as friction, they tend to aggregate and transform into naked fat (free faυ).

This free fat is easily oxidized, which causes deterioration in the flavor of milk powder and also causes a decrease in the fluidity of milk powder as a powder.

Powders having such properties are not only powdered milk, but also powdered soups and the like, which are problems that need to be solved in the design of manufacturing equipment. In addition, skim milk powder, instant coffee powder, and the like, which contain almost no fat, become fine particles due to the destruction of agglomerates, resulting in a decrease in affinity with water.

On the other hand, in order to efficiently collect <1M of manufactured edible powder, there are cyclone collectors that utilize centrifugal force while still having the above-mentioned problems, and bag filters that use filtration methods but have the drawback of "clogging". had been adopted.

Generally, when milk powder is collected by passing through the cyclone collector, it is said that 1/4 to 1/3 of the fat content in 26% fat-containing powdered milk changes to the form of free fat. Furthermore, powder that tends to adhere to walls causes problems due to blockage of ducts and adhesion to fan blades and surrounding areas. In addition, when the above-mentioned bag filter has a high mixed concentration of powder, or when processing milk powder that is highly hygroscopic and adhesive, it becomes clogged and the collection efficiency decreases.
It becomes difficult to use 41 consecutive times for a long time.

Furthermore, various types of collision-type separators, inversion-type, or louver-type dust collectors also have problems such as a decrease in collection efficiency due to re-scattering, and the generation of free fat and powdery deterioration due to channel blockage and compression caused by collisions. Because of this, it has not been used to separate edible powders.

Therefore, in view of the above-mentioned problems, the present invention has developed a powder that first separates and collects edible powder from the air while preventing the powder from being crushed, and further maintains the collection efficiency as high as possible. By developing a powder separation device and using this device in combination with a powder production machine, powder transportation machine, cyclone collector, etc., we aim to construct a unit that can maintain the quality of powder and collect it sufficiently. This is a technical issue.

[Means for solving problems]

The powder separation device of the present invention will be explained with reference to FIG. A separation chamber 1 is provided with an exhaust port 4 and is hollow, and a cylindrical chamber 1 that protrudes inward from the upper surface 11 of the separation chamber 1 and has an inverted conical shape and an opening 13 formed in the bottom 12. The powder mixed gas inflow pipe 2 is spaced apart from the opening 13 of the bottom part 12 of the powder mixed gas inflow pipe 2 by a predetermined distance inside the separation chamber 1 and has a diameter substantially the same as that of the opening 13 for taking in the powder. Mouth 14
It has a tubular powder collecting part 3 which is provided so as to face each other and has an air extraction port 5 for extracting a predetermined amount of air. Then, the gas component of the powder mixed gas is taken out from the gap 15 between the opening 13 and the powder intake port 14 to the separation chamber at an angle from the center line direction of the powder mixed gas inflow pipe, and It is characterized in that after the powder separated in the section 15 enters the powder collecting section 3, it settles at approximately the final settling velocity by adjusting the above-mentioned displacement amount and the above-mentioned bleed air amount.

Further, the powder processing unit of the present invention is characterized in that the powder separation device is connected to the powder mixed gas extraction side of the air mixed powder pumping device or the hot air mixing type powder drying device.

[Effect]

By arranging the powder mixed gas inflow pipe 2 having the opening 13 to face the powder collecting section 3 through a gap 15 separated by a predetermined distance, and performing exhaust through the exhaust port 4 of the separation chamber 1. Due to the exhaust, the gas in the mixed gas is taken out to the separation chamber 1 at an angle from the center line direction of the powder mixed gas inflow pipe 2, while the powder is removed by inertia.
It rushes toward the powder intake port 14 of the powder collecting section 3.

It is desirable to collect the injected powder without strongly pressing it against the wall or bottom surface, but in the powder separator of the present invention, this is achieved by adjusting the exhaust volume and the bleed volume. That is, the powder that has entered the powder collecting section 3 sinks at approximately the final settling velocity within the powder collecting section 3 where air is extracted from the air extraction port, and therefore, the powder in the powder collecting section 3 sinks at approximately the final settling velocity. Collection will be performed without causing any crushing or the like. Here, if the amount of extracted air is small compared to the amount of exhaust air, the degree to which the powder to be collected will scatter from the collection section will increase due to turbulence in the airflow within the powder collection section 3. On the other hand, if the amount of bleed air is large compared to the amount of exhaust air, most of the powder that has entered the powder collection section 3 will be trapped in the bleed port. This results in more leakage and lowers the collection efficiency.

Therefore, by adjusting the exhaust volume and the bleed volume, it is possible to drop the powder at a speed close to the final sedimentation velocity and effectively collect the powder without crushing it.

〔Example〕

Preferred embodiments of the present invention will be described with reference to the drawings.

First, the structure of the powder separator of this embodiment will be specifically explained with reference to FIG.

As shown in FIG. 1, the powder separator of this embodiment has a separation chamber 1 as the main body of the separation device, and a powder mixture gas flows into the separation chamber 1 so as to face each other in the vertical direction. A tube 2 and a powder collection section 3 are provided.

The separation chamber 1 has a substantially cylindrical shape and is hollow inside. The outer shell of the separation chamber 1 has a structure that is divided into upper and lower parts, and can be separated into an upper separation chamber member 21 and a lower separation chamber member 22. The cylindrical powder mixed gas inflow pipe 2 is disposed in the upper separation chamber member 21 so as to penetrate through the upper surface 11 of the separation chamber 1.
and the upper separation chamber member 21 are fixed concentrically so that there is sufficient space between the outer wall of the powder mixed gas inflow pipe 2 and the inner wall of the upper separation chamber member 21.

Similarly, the powder collecting section 3 is fixed concentrically to the lower separation chamber member 22 so as to pass through the bottom surface 23 thereof. Flange portions 24 and 25 are formed at the joint portions of the upper separation chamber member 21 and the lower separation chamber member 22, respectively. A joining member 26 as a spacer is interposed between each of these flange portions 24 and 25, and the upper and lower separation chamber members 21 and 22 are joined to function as the separation chamber 1.

The joining member 26 has a function of connecting the flange portions 24 and 25 of the upper separation chamber member 21 and the lower separation chamber member 22, which are vertically separable. And the powder content 1i of this example
In the i1 device, the joining member 26 is connected to the gap 15 described later.
It is a member that determines the distance between the two. An exhaust port 4 for taking out the gas from the powder mixed gas inflow pipe 2 is provided perpendicularly from the outer circumferential surface of the lower separation chamber member 22 on the lower side of the outer circumferential surface of the separation chamber l. . This exhaust port 4 is connected to a required exhaust fan, and can exhaust a specified amount of exhaust NlO gas from the inside of the separation chamber 1 to the outside.

The powder mixed gas inflow pipe 2 is a cylindrical member with a diameter D1. The powder mixed gas inflow pipe 2 projects vertically from the top surface 11 of the separation chamber 1 toward the interior of the separation chamber 1. The center line of the tube is in the vertical direction of the device, and also partially coincides with the direction of the air flow inside the powder mixed gas inflow tube 2. The bottom part 12 of this powder mixed gas inflow pipe 2
has an inverted conical shape, and its bottom side is tapered. This tapered angle of inclination α is about 60 degrees in this embodiment, but can be selected as appropriate depending on the type of powder. An opening 13 having an opening surface perpendicular to the center line of the tube is formed in the tapered bottom. The diameter d of this opening 13 is smaller than the diameter D1.

The ratio between the diameter d of this opening 13 and the diameter D1 of the cylindrical portion of the powder mixed gas inflow pipe 2 is one factor that determines the flow velocity at the tip.

Further, the diameter d of the opening 13 directly becomes the diameter d of the powder intake port 14 of the powder collecting section 3.

The powder collecting section 3 has a diameter that is the same as or larger than the diameter D+' of the powder mixed gas inflow pipe 2 provided opposite to the powder mixed gas inflow pipe 2 inside the separation chamber 1. It is a cylindrical housing portion (with the same diameter in the illustrated example). This powder collecting section 3 includes a bottom section 23 of the lower separation chamber member 22.
It is provided so as to penetrate concentrically in the vertical direction. A re-scattering prevention plate 27 having a surface that is continuous with the peripheral wall 28 and perpendicular to the axis is provided on the opposite surface side of the powder collecting section 3 that faces the powder mixed gas inflow pipe 2 . A powder intake port 14 is provided in the center of the re-scattering prevention plate 27, facing the opening 13 at the bottom of the powder mixed gas inflow pipe 2. Here, the powder intake port 14 and the opening 13 are separated by a predetermined distance klS. The void portion 15 spaced apart by a predetermined distance 5s is annularly opened not in the extending direction of the center line of the powder mixed gas inflow pipe 2 but on the circumferential side of the cylinder. Therefore, the gas blown out from the opening 13 is taken out at a sharp angle into the separation chamber 1 by being exhausted from the exhaust port 4 in the gap 15 . The distance S of the gap 15 depends on the thickness of the joining member 26 and the powder mixed gas inlet pipe 2. It can be adjusted by vertically operating the disguise body collecting section 3, etc.

A cylindrical peripheral wall 28 continues at the lower part of the surface of the powder collecting section 3 facing the powder mixed gas inflow pipe 2, that is, at the lower part of the re-scattering prevention plate 27. Its surrounding wall 2
8 is continuous with the flexible member 29 outside the separation chamber 1. The flexible member 29 is located at the bottom of the powder collecting section 3 and is continuous with a bottom storage section 30 in which powder is accumulated and stored. An air bleed port 5 for bleeding a part of the gas sent into the powder collecting section 3 is provided in a part of the peripheral wall 28 so as to perpendicularly penetrate the peripheral surface of the peripheral wall 28. There is. The tip 31 of the air bleed port 5 opens toward the bottom near the center line of the powder collecting section 3, and is configured to bleed a predetermined amount of air IL from there. In addition, the air bleed port 5 is connected to a required air bleed device outside the device, and as described later, from the balance between the predetermined amount of bleed air aL and the predetermined amount of exhaust TJ 1 o, it is possible to generate powder without crushing and with high efficiency. Achieve the collection of A vibrator 32 is provided on the outer periphery of the powder collecting section 3 to vibrate the powder collecting section 3 to prevent powder from adhering to the vibrator 32 .

Here, the operating state of the powder separator will be explained with reference to FIG. is introduced with the flow direction being vertically downward.

Then, this powder mixed gas is transferred to the powder mixed gas inflow pipe 2.
The mixture flows through the inside of the powder mixture gas along the flow direction (.Subsequently, at the bottom 12 of the inverted conical powder mixed gas inlet pipe 2, the opening 1
3 and the diameter D1 of the powder mixed gas inflow pipe 2, the flow rate is accelerated.

Next, in the powder mixed gas blown out from the opening 13 at the bottom of the powder mixed gas inflow pipe 2, the gas component first flows in the void 15 at an angle from the vertical direction, that is, from the vertical direction in this embodiment. It is taken out into the separation chamber 1 at an angle of about 90 degrees. This extracted powder mixed gas is discharged from the exhaust port 4 provided in the separation chamber 1 to a predetermined air volume FJ). o
It will be exhausted by this. On the other hand, the powder is flowed together with the gas up to the opening 13 of the powder mixed gas inflow pipe 2, but due to the action of inertia and gravity, it is not taken out into the separation chamber 1, and it continues straight ahead to form the powder. It enters the inside of the powder collecting section 3 through the powder intake port 14 of the collecting section 3 .

In this way, separation of gas and powder is performed in the gap 15 between the powder mixed gas inflow pipe 2 and the powder collecting section 3, and this powder collecting section 3 collects the powder that has entered. However, in the powder separator of this embodiment, it is possible to collect the powder while preventing crushing and the like. In other words, the flow velocity of the powder that has entered the powder collecting section 3 is suppressed because the air volume is large enough for the gas to be discharged from the bleed port 5, and the flow rate is approximately equal to the condition where gravity and the abrasive force of the fluid are balanced. It continues to settle at the terminal sedimentation velocity.

Therefore, it is possible to avoid collision with an impact plate or the like or friction such as being pressed against a wall or the like, and when the powder is used as milk powder, destruction of the powder and increase in free fat can be prevented.

Here, the air bleed LtIL from the air bleed port 5 has a constant relationship with the above-mentioned displacement amount of 1°, and its adjustment does not reduce the collection ability. This is the displacement! . Compared to the amount of bleed air! If , is too small, the powder will scatter from the collection part due to turbulence of air flow in the powder collection part 3 (the degree will increase. Also, the amount of extracted air l, If is too large, the powder will be taken out from the powder collecting section 3 through the air bleed port 5, and the powder will not be collected in the bottom storage section 30, reducing the efficiency of collection. For example, in a powder separator of

(bleeding rate) approximately 5 to 25%, more preferably 7 to 20%
It is said that This improves collection efficiency.

In addition, a re-scattering prevention plate 27 provided on the side of the powder collecting section 3 facing the powder mixed gas inflow pipe 2 prevents powder from entering the separation chamber 1 from inside the powder collecting section 3. This prevents it from being rolled up.

Further, if the exhaust IA and the amount of extracted air 1L are not properly adjusted, turbulence of the airflow within the powder collecting section 3 will occur, but re-scattering can also be prevented in this case.

Furthermore, the vibrator 32 provided on the outer periphery of the powder collecting section 3 can prevent powder from adhering to the powder collecting section 3.

Next, a powder processing unit constructed using the powder separator of this embodiment will be explained with reference to FIGS. 2 and 3.

First, a powder processing unit for conveying powder has a configuration shown in FIG. 2, for example. Figure 2 shows a powder processing unit including an air-mixed powder pumping device, and in Figure 2,
The device 40 shown within the broken line is a powder separation device having the above-described configuration. In addition, in this example, the air mixed powder pumping device is
Powder supply section 41, blower 42, blow pipe 44, introduction pipe 45
．． It consists of 46 pieces. Initially, powder is accumulated in the powder supply section 41, which is supplied with pressurized air. The blower 42 draws transport air. The powder accumulated in the powder supply section 41 is mixed with air sent from the powder supply section 41 through the blow pipe 44 from the blower 42, and passes through the introduction pipe 45 standing vertically. The powder is supplied to the powder mixed gas inflow pipe 2 of the powder separator 40 through an introduction pipe 46 having a diameter larger than that of the introduction pipe 45 and having an oval shape. In the powder separator 40, the powder and gas are effectively separated by a balance between the exhaust volume and the bleed volume, thereby achieving collection with suppressed crushing and the like.

Further, as a powder processing unit for further improving the collection efficiency, a structure shown in FIG. 3 can be used.

In the configuration shown in FIG. 3, the powder separation device 50 having the above-described configuration is connected to the powder mixed gas extraction side of the hot air mixing type powder drying device 51. In this powder separator 50, the powder and gas are effectively separated by the balance between the exhaust volume and the bleed volume as described above, and collection with suppressed crushing and the like is realized.

The powder separator 50 has an exhaust port 4 and an air bleed port 5, and the exhaust port 4 and the air bleed port 5 are connected to a cyclone collector 5.
Connected to 2. Powder that is not collected by the powder separator 50 is discharged from the exhaust port 4 and the air bleed port 5,
By connecting the cyclone collector 52 to the exhaust port 4 and the air extraction port 5 in this manner, it is possible to further improve the collection efficiency.

Further, the powder separator of this embodiment can be modified as shown in FIG. This powder separator 60 has substantially the same configuration as the powder separator described above, and an opening 13 is provided at the bottom 12 of the powder mixed gas inlet pipe 2 which is shaped like an inverted cone. A powder intake port 1 is provided on the re-scattering prevention plate 27 on the powder collecting section 3 side opposite to the opening 13.
4 is provided. In this powder separation device 60, an auxiliary plate 61 is formed on the outer peripheral side of the bottom portion 12 of the powder mixed gas inflow pipe 2. This auxiliary plate 61 is provided along the periphery of the opening 13 so as to face the re-scattering prevention plate 27 . By providing such an auxiliary plate 61, the collection efficiency can be further improved.

Next, the results of experiments conducted on the powder separator of this example will be explained. Experiments (2) regarding collection efficiency and (2) experiment regarding increase in free fat were conducted using the powder separator of this example.

Experiment■ First, Experiment I is an experiment regarding powder collection efficiency.
Table 1 shows the relationship between the shape of the openings 13, the distance S between the openings, and the bleed rate.

Regarding this experiment (2), the symbols and numbers in Table 1 have the following meanings.

・Type of raw material powder used SM: Skim milk powder (skim mlk), average particle size approximately 1
00μ granular pollen WM: whole milk powder (whole m1lk), multiple aggregated pollen with an average particle size of about 80μ, opening shape (*) ■: Powder/powder mixed gas large inlet tube 200 muφ) made into a cylindrical shape as it is ■:: The lower half of the powder mixed gas inflow pipe is cylindrical with a diameter of 100*m. ■::1 As shown in the figure, the outlet of the powder mixed gas inflow pipe is shaped like an inverted cone of approximately 60° (exit diameter: 100 mφ). Note that the re-scattering prevention plate 27 was ring-shaped so as to have the same diameter as the opening diameter. Also, the bleed rate is (−
) indicates that air bleed is omitted.

(The following is a margin) Table 1 Continuation of Table 1 The purpose of this experiment 1r was to set the optimal conditions for the equipment to be used, and the following results were obtained from the data shown in Table 1. .

First, in Experimental Examples A-B, the powder mixed gas inflow pipe is set to d/DI=1 at its opening (remains cylindrical), and as a result, the powdered mixed gas inflow pipe to be collected is No. 8
This shows that more than 0% was transferred to the exhaust port, resulting in extremely low collection efficiency.

Second, in Example C, the opening is narrowed to have a funnel-shaped opening with a cylindrical guide tube at the tip, and as a matter of course, the air velocity at the opening increases. , indicating that the milk powder is re-splattered and blown up in the collection section, and the collection efficiency is low.

Thirdly, in Experimental Example D-V, the opening was narrowed down to an inverted conical shape (Fig. 1 α-60
', d/D+ = %), the open part of the re-scattering prevention plate (
The diameter of the powder intake port was 100n.

Further, a downwardly opened air bleed port was provided below the powdered milk collecting section.

Fourth, in Experimental Examples D-P, experimental data was obtained for three groups using granulated skimmed milk powder as the milk powder material and keeping the distance between the openings (void area) constant. From these data, it was found that there is a relatively strong correlation between the extraction rate and the collection efficiency, and that it is necessary to set the extraction rate to about 7 to 20% in order to improve the collection efficiency.

Fifth, in Experimental Example Q-V, whole milk powder was used as the milk powder material, and an attempt was made to apply it to the prevention of free fat generation in skim-containing powder, which is one of the objectives of the present invention. This experiment confirmed that it is compatible with whole milk powder and that a practical collection efficiency can be expected.

Experiment (2) This was an experiment to determine whether or not there was an increase in free fat when the present apparatus was used to separate and collect powder from a powder mixed gas, and Experimental Example S in Experiment (2) was adopted as the setting conditions.

The results are shown in Table 2.

Here, the raw material powder used in the experiment ① is: Example-1: Full-fat milk powder - milk powder from the part of concentrated raw milk that naturally falls into the spray drying chamber (fat content 26.2%) Example-28 Synthetic milk powder Milk = skimmed milk? This is milk powder (fat content: 28.5%) that is layered, homogenized with the addition of vegetable fat, spray-dried, and allowed to fall naturally into a drying room.

In addition, regarding the condition settings for Example-1 and Example-2, (Example-1) Weigh out 120 kg of raw milk powder, lightly mix it to make it homogeneous, and divide it into two parts. The entire amount was supplied to the powder separator of this example using a pneumatic conveyor, and the milk powder was collected.

(B) Further, the exhaust gas containing milk powder that could not be collected by this device and the extracted air were combined and sent to a cyclone collector, where they were almost completely collected.

(C) The above (A) and (B) were combined and mixed uniformly with gentle force.

(D) As a comparative example, the remaining amount of 60 kg was sent to the same cyclone collector as in (B) using the same air mixing powder feeding device as in (A), and the powder was separated and almost completely collected. .

(Example 2) The experiment was repeated under the same conditions as Example 1 except that synthetic milk powder was used as the raw material powder.

(Hereinafter, blank space) Table 2 (The FF value * in Table 2 indicates the free fat content. Carbon tetrachloride is added to powdered milk, and the fat weight extracted by shaking is used as a percentage of the total weight of powdered milk.) (According to the commonly used free fat measurement method.) Based on the experimental results shown in Table 2, (A).

It can be seen that the increase in free fat is suppressed in (Ao). (The reason why the FF values in (A) and (A') above are lower than the raw material powder is because the average particle size of the separated and collected milk powder is different from that of the milk powder transferred to the cyclone collector. ) In other words, in the conventional cyclone collector, powdered milk is pressed against the surrounding wall surface and causes friction, resulting in an increase in 'f1 fat separation. However, in the powder separator of this embodiment,
There is no pressing due to centrifugal force or I2 friction, and the milk powder that enters the powder collecting section 3 is immediately decelerated and accumulated at approximately the terminal sedimentation velocity, which improves the quality of the milk powder by preventing the increase of free fat and preventing the collision and destruction of powder particles. was found to be able to be maintained well.

As explained above, the powder separation device of this embodiment can separate gas and powder using inertial force, and unlike conventional devices, it is pressed against a wall etc. by centrifugal force and crushed. This solves problems such as problems such as the occurrence of problems and the inability to perform continuous processing for a long period of time. In particular, by adjusting the exhaust volume and bleed volume, collection that prevents powder from being crushed or the like can be achieved. Therefore, when separating milk powder using the powder separator of this embodiment, it is possible to prevent the destruction of fat globules and suppress the increase in a fat separation, prevent the destruction of particles, and improve the solubility of milk powder. 1 Dispersibility can be improved. Moreover, it is suitable for treating powder that has adhesive properties.

It goes without saying that this device can also be used as a general dust collector. Further, as a powder, it can be applied particularly to powders that are difficult to handle, such as powdered milk, such as infant formula powdered milk and whole milk powder.

It can be applied to various j5) milks such as skim milk powder and powdered cream. Moreover, it is not limited to powdered milk, but can also be used for other edible powders, such as powdered soups, granular powdered foods such as instant coffee, etc.

Further, the powder separator and powder processing unit of the present invention can be modified in various ways without departing from the gist of the present invention.

[Effects of the Invention] By applying the powder separation device of the present invention to the powder separation process, it is possible to prevent powder crushing, friction, etc., and especially in milk powder containing fat, generation of free fat can be prevented. and ensure quality stability. In addition, it is possible to handle adhesive powders, and continuous processing for long periods of time is possible. Furthermore, by using the above-mentioned powder separation device in a powder processing unit, a suitable powder separation effect can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an example of a powder separation device of the present invention, FIG. 2 is a partially cutaway side view for explaining an example of a powder processing unit of the present invention, and FIG. 3 is a powder processing unit of the present invention. FIG. 4 is a schematic diagram for explaining another example of the unit, and FIG. 4 is a schematic diagram for explaining an example of the technology preceding the powder separator of the present invention. Moreover, FIG. 5 is a sectional view of a main part for explaining a modification of the powder separator of the present invention. 1... Separation chamber 2... Powder mixed gas inflow pipe 3... Powder collection section 4... Exhaust port 5... Air bleed port 13... Opening 14... Powder intake Portion 15: Gap patent applicant: Meiji Dairy Co., Ltd. Patent attorney Akira Koike (and 2 others) Figure 1 Figure 3 Figure 4 Figure 5

Claims (1)

[Scope of Claims] (1) A separation chamber provided with an exhaust port for discharging a predetermined amount of exhaust gas, and an inverted conical shape that protrudes inward from the upper surface of the separation chamber and has an opening formed at the bottom. The cylindrical powder mixed gas inflow pipe and the powder intake port, which is spaced apart from the opening of the powder mixed gas inflow pipe and has approximately the same diameter as the opening, face each other inside the separation chamber. It has a tubular powder collection part provided with an air extraction port for extracting a predetermined amount of air, and the powder mixture gas is collected in the gap between the opening and the powder intake port. After the powder mixture gas is taken out into the separation chamber at an angle from the center line direction of the powder mixed gas inflow pipe, and the powder separated in the gap enters the powder collection section, the above displacement amount and the above bleed air amount are A powder separator characterized in that it settles at a substantially terminal settling velocity by adjustment. (2) The powder separation device according to claim 1, wherein the axis of the powder mixed gas inflow pipe is vertical. (3) The powder separator according to claim 1, wherein the opening end of the bleed port is opened downward. (4) The powder separator according to claim 1, further comprising a re-scattering prevention plate installed at the upper end of the powder collecting section. (5) Claim 1, characterized in that the distance between the gap between the opening of the powder mixed gas inflow pipe and the powder intake port of the powder collecting section is adjustable. Powder separation device as described. (6) The powder separator according to claim 1, wherein an auxiliary plate is provided on the outer peripheral side of the bottom of the powder mixed gas inflow pipe. (7) The powder separation device according to claim 1, wherein the gas exhausted from the exhaust port and the gas extracted from the bleed port are combined and connected to a cyclone collector. (8) A separation chamber provided with an exhaust port for discharging a predetermined amount of exhaust gas, and a cylindrical powder projecting inward from the upper surface of the separation chamber and having an inverted conical shape and an opening at the bottom. A powder mixture gas inflow pipe and a powder intake port which is spaced apart from the opening of the powder mixture gas inflow pipe and has approximately the same diameter as the opening in the separation chamber are provided so as to face each other, and have a predetermined diameter. It has a tubular powder collection part in which an air bleed port for extracting the amount of air is disposed, and the gas content of the powder mixture gas is mixed with the powder in the gap between the opening and the powder intake port. After the powder is taken out to the separation chamber at an angle from the center line direction of the gas inflow pipe and separated in the gap, it enters the powder collection section, and then the final sedimentation velocity is adjusted by adjusting the displacement amount and the extraction amount. This is a powder processing unit that has a powder separator that settles with a 100°C, and the powder separator is connected to the powder mixed gas take-out side of an air-mixed powder pumping device to transport the powder. (9) A separation chamber provided with an exhaust port for discharging a predetermined amount of exhaust gas, and a cylindrical powder that protrudes inward from the upper surface of the separation chamber and has an inverted conical shape and an opening at the bottom. A powder mixture gas inflow pipe and a powder intake port which is spaced apart from the opening of the powder mixture gas inflow pipe and has approximately the same diameter as the opening in the separation chamber are provided so as to face each other, and have a predetermined diameter. It has a tubular powder collection part in which an air bleed port for extracting the amount of air is disposed, and the gas content of the powder mixture gas is mixed with the powder in the gap between the opening and the powder intake port. After the powder is taken out to the separation chamber at an angle from the center line direction of the gas inflow pipe and separated in the gap, it enters the powder collection section, and then the final sedimentation velocity is adjusted by adjusting the displacement amount and the extraction amount. This is a powder processing unit that has a powder separator that settles with a 100-degree drop, and the powder separator is connected to the powder mixed gas extraction side of a hot air mixing type powder dryer to separate the powder.