JP2559775B2 - Powder separation device and powder processing unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention is a powder containing gas such as air, in particular, edible powder, which separates powder and gas from each other by utilizing a linear inertial force and is in a stable state A powder separation device for obtaining aggregates, for preventing the powder from rubbing against the inner wall of the device, and for eliminating gas without colliding with the inner wall and destroying the porosity of the powder particles. It relates to the device.

Further, according to the present invention, a powder separating device for separating powder and gas is placed in a post-process of an air-mixed powder pressure feeding device or a powder manufacturing machine, and after collecting most of the sent powder. The present invention relates to a powder processing unit in which a collection device having a high collection rate, such as a cyclone collector, is connected in series in the next step.

[Conventional technology]

Cyclone collectors that utilize centrifugal force and bag filters that separate by filtration are known as devices that have already been put to practical use as a device for collecting edible powders such as milk powder and instant coffee.

In the process of producing powder from a liquid raw material, a powder production machine such as a spray dryer that atomizes the concentrated raw material and mixes it with dry hot air to dry is used. In order to separate and collect, conventionally, a unit incorporating the cyclone collector or the bag filter is used between the powder manufacturing machine and the air outlet.

The same applies to gas separation in an air-mixed powder conveyer that continuously conveys the obtained powder to another place.

On the other hand, in fields other than edible powder, various devices such as collision type, reversing type, louver type, etc. have been developed and put into practical use by utilizing inertial force for the purpose of transporting, classifying or collecting dust, especially fine inorganic powder. There is.

Here, of these, the reasoning that is considered to be close to the invention of the present application will be presented and its outline will be described.
Classification Performance of Virtual Inpactor "(Chemical Engineering Proceedings (Chemical Engineering Society) Volume 4, Issue 4 (197)
The main part of 8)) is the result of theoretically examining the effects of straight flow rate, slit spacing, fluid viscosity, and classification tube wall thickness on the classification performance of a virtual impactor, which is a conventionally known classification experimenter. It is a report. The experimental result is the fourth
In the structure shown in the figure, two circular tubes 102, 103 having an inner diameter of 16 mm are installed inside the chamber 101 so as to face each other,
Circumferential slits 104 are provided on the opposing cut surfaces of the circular tubes, and aerosolized methylene blue / uranin fine particles are supplied from above to obtain the classification efficiency when the straight flow rate is set to about 1/10. is there.

In this experimental device, when the aerosol is ejected from the upper circular tube 102 and sucked into the lower circular tube 103, coarse particles having a strong inertial force are transferred to the lower circular tube 103, and fine particles having a weak inertial force are slit 104 The particles flow out to the side and flow into the lower chamber 105, where both particle groups can be classified. In this experimental apparatus, the aerosolized methylene blue / uranin fine particles were supplied using an aerosol generator 106 and a mixer 107, the lower circular tube 103 was connected to a vacuum pump 110 via a filter 108 and a meter 109, and a chamber. A flow meter 112 and a blower 113 are connected to the lower portion 105 via a filter 111.

In addition, when other similar prior art is presented,
-21493, a technique of a powder / granule separator in which the separation rate can be adjusted by advancing and retracting a collision plate, and JP-A-58-58
-74118 technology of a separation device that constitutes an apparatus consisting of a unit formed by a space consisting of an expanding portion and a contracting portion that communicate with each other to prevent agglomeration of particles to be separated and perform effective separation, Optimum dust collection according to gas conditions with a simple structure by arranging the baffle rotatably so as to change the size of the projected area of the plate-like baffle described in JP-B-60-36808 There is a technology of a louver type dust collector that does the above.

[Problems to be solved by the invention]

Powdered milk, which is edible powder, has the following properties, unlike powders such as general dust. That is, powdered milk has many components such as protein, fat, lactose, and inorganic components, and when viewed as particles, it is not a single particle but approximately 20 particles.
Several single grains of about 30 μm are present in the state of being bound together.
Further, there are many voids between the particles, and they have a property of being relatively weak against external force. Therefore, it is likely to be crushed by the collision and friction with the inner wall of the processing apparatus, and it becomes a cause of lowering the affinity (meltability) with water as it is atomized.

In particular, the fat contained in the milk powder particles is wrapped in a protein protective film to form spherical particles having a size of 1 to 3 μm and is in a substantially uniformly dispersed state. The fat ball protective film collides with the inner wall of the device or When destroyed by an external force such as friction, individual fat globules tend to aggregate and transform into naked free fat. This free fat is easily oxidized, which causes deterioration of the flavor of the milk powder and also causes deterioration of the fluidity of the powder particles as a powder.

The powder having such a property is not only powdered milk but also a problem to be solved in designing a manufacturing apparatus for powdered soup and the like. Also, skimmed milk powder containing almost no fat, instant coffee powder, and the like have a reduced affinity for water due to atomization due to destruction of aggregated particles.

On the other hand, a cyclone collector using centrifugal force or a bag filter using a filtration method while having the problem of "clogging" while leaving the above problems due to the proposition that the produced edible powder is efficiently collected. It was adopted.

Generally, when milk powder is collected by passing through the cyclone collector, the amount of fat contained in milk powder containing 26% fat is
It is said that 1/4 to 1/3 changes to the form of free fat, and in the case of powder that easily adheres to the wall surface, problems occur due to blockage of ducts and adhesion to fan blades and the periphery.
Further, in the above bag filter, when the mixed concentration of powder is high, or when processing milk powder having high hygroscopicity and adhesiveness, clogging occurs and the collection efficiency decreases, and continuous use for a long time is required. Will be difficult.

Furthermore, even in various collision-type separation devices and reversal-type or louver-type dust collectors, there is a problem in that the collection efficiency is reduced due to re-scattering, and the flow passage is blocked due to collisions and free fat is generated due to compression and powdery deterioration. Because of this, it has not been conventionally used for separating edible powder.

Therefore, in the present invention, in view of the above-mentioned problems, first, a powder that separates and collects the edible powder from the air while preventing the powder from crushing, and further maintains the collection efficiency as high as possible. To develop a body separation device and to construct a unit that can maintain the quality of powder and sufficiently collect it by combining it with a powder manufacturing machine, powder transporter, cyclone collector, etc. This is a technical issue.

[Means for solving problems]

The powder separating apparatus of the present invention will be described with reference to FIG. 1 corresponding to the embodiment. The powder separating apparatus of the present invention is an exhaust gas that exhausts a predetermined exhaust amount in order to solve the above-mentioned problems. A separation chamber 1 having a port 4 and a hollow space, and the separation chamber 1
A cylindrical powder mixed gas inflow pipe 2 which protrudes inward from the upper surface 11 and has an inverted conical shape and an opening 13 formed in a bottom 12; and the powder inside the separation chamber 1. A bleed port for bleeding a predetermined amount of bleed air, which is provided so as to face a powder intake port 14 having a diameter substantially the same as that of the opening 13 of the bottom part 12 of the mixed gas inflow pipe 2 and a predetermined distance. 5
It has a tubular powder collecting part 3 in which is arranged. Then, the gas component of the powder mixed gas is taken out from the space 15 between the opening 13 and the powder intake port 14 into the separation chamber at an angle from the center line direction of the powder mixed gas inflow pipe, and the space is formed. After the powder separated in the section 15 enters the powder collecting section 3, it is settled at a substantially terminal settling speed by adjusting the exhaust amount and the extraction amount.

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

[Action]

By allowing the powder mixed gas inflow pipe 2 having the opening 13 to face the powder collecting unit 3 through the void 15 which is separated by a predetermined distance, the gas is exhausted from the exhaust port 4 of the separation chamber 1. ,
Due to the exhaust, the gas in the mixed gas is taken out into the separation chamber 1 at an angle from the center line direction of the powder mixed gas inflow pipe 2, while the powder is trapped by the inertial force in the powder. It rushes toward the powder intake port 14 of the collecting unit 3.

Then, it is desirable to collect the powdered powder without pressing it against the wall surface or the bottom surface strongly, but in the powder separating apparatus of the present invention, this is realized by adjusting the exhaust amount and the extraction amount.
That is, the powder that has rushed into the powder collecting unit 3 sinks at a substantially terminal settling velocity in the powder collecting unit 3 that is extracted from the extraction port, and thus the powder in the powder collecting unit 3 is Collection will be performed without crushing. Here, if the amount of extracted air is small with respect to the amount of exhaust, the degree of the powder to be collected from the collection unit increases due to turbulence of the air flow in the powder collection unit 3 or the like. However, the powder cannot be collected efficiently. On the other hand, on the contrary, when the extraction amount is larger than the exhaust amount,
Most of the powder that has rushed into the powder collection unit 3 flows out from the extraction port, which reduces the collection efficiency. Therefore, by adjusting the exhaust amount and the extraction amount, it is possible to drop the powder at a speed close to the terminal sedimentation speed and to effectively collect the powder without crushing it.

〔Example〕

A preferred embodiment of the present invention will be described with reference to the drawings.

First, the structure of the powder separating apparatus of this embodiment will be specifically described with reference to FIG.

As shown in FIG. 1, the powder separation apparatus of the present embodiment has a separation chamber 1 as a main body of the separation apparatus, and the powder mixture gas inflows inside the separation chamber 1 so as to face each other in the vertical direction. Tube 2
And a powder collector 3 are provided.

The separation chamber 1 has a substantially cylindrical shape, and the inside thereof is hollow. The outside of the separation chamber 1 has a structure that is divided into an upper part and a lower part, and an upper separation chamber member 21 and a lower separation chamber member.
It can be separated into 22. The upper separation chamber member 21 includes a separation chamber 1
The cylindrical powder mixed gas inflow pipe 2 is arranged so as to penetrate the upper surface portion 11 of the powder mixed gas inflow pipe 2 and the upper separation chamber member 21. The outer wall of 2 and the inner wall of the upper separation chamber member 21 are concentrically fixed with a sufficient margin. The lower separation chamber member 22
Similarly, the powder collecting portion 3 is concentrically fixed so as to penetrate the bottom surface portion 23. These upper separation chamber members 21
Flange portions 24 and 25 are formed at the joints between the lower separation chamber member 22 and the lower separation chamber member 22, respectively. A joint member 26 as a spacer is interposed between the 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. Further, in the powder separating apparatus of the present embodiment, the joining member 26 is a member that determines the distance at which the void 15 described later is separated. On the lower side of the outer peripheral surface of the separation chamber 1, an exhaust port 4 for taking out a gas component from the powder mixed gas inlet pipe 2 is provided vertically from the outer peripheral surface of the lower separation chamber member 22. There is. The exhaust port 4 is connected to a required exhaust fan and can discharge a gas having a predetermined exhaust amount l ₀ from the inside of the separation chamber 1 to the outside.

The powder mixed gas inflow pipe 2 is a cylindrical member having a diameter D ₁ . The powder mixed gas inflow pipe 2 is projected from the surface of the upper surface portion 11 of the separation chamber 1 in the vertical direction toward the inside of the separation chamber 1. The center line of the tube is the vertical direction of the apparatus, and further coincides with the direction of the air flow inside the powder mixed gas inflow tube 2. The bottom portion 12 of the powder mixed gas inflow pipe 2 is
It has an inverted conical shape, and its bottom side is tapered. In this embodiment, the taper angle of inclination α is approximately
Although it is 60 degrees, it can be appropriately selected depending on the type of powder. An opening 13 having an opening surface perpendicular to the center line of the pipe is formed in the tapered bottom portion. The diameter d of the opening 13 is smaller than the diameter D ₁ . This opening 13
The ratio of the diameter d to the diameter D ₁ of the cylindrical portion of the powder mixed gas inflow pipe 2 is one factor that determines the flow velocity at the tip. Also the opening
The diameter d of 13 becomes the diameter d of the powder intake port 14 of the powder collector 3 as it is.

The powder collecting section 3 has a diameter D _{1 which} is the same as or larger than the diameter D _{1 of the} powder mixed gas inflow pipe 2 which is provided inside the separation chamber 1 so as to face the powder mixed gas inflow pipe 2. It is a cylindrical accommodating portion of ₂ (same diameter in the illustrated example). The powder collecting portion 3 is provided so as to concentrically penetrate from the bottom surface portion 23 of the lower separation chamber member 22 in the vertical direction. A re-scattering prevention plate 27 having a surface continuous with the peripheral wall 28 and perpendicular to the axis is provided on the surface of the powder collection unit 3 facing the powder mixed gas inflow pipe 2. At the center of the re-scattering prevention plate 27, a powder intake port 14 is provided 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 S. The void 15 separated by the predetermined distance S
Has a ring-shaped opening on the side of the peripheral side of the cylindrical body, not on the extending direction of the center line of the powder mixed gas inflow pipe 2. Therefore, the gas blown out from the opening 13 is taken out to the inside of the separation chamber 1 at a sharp angle by the exhaust from the exhaust port 4 in the void 15. It should be noted that the distance S of the void 15 is determined by the thickness of the joining member 26 and the powder mixed gas inflow pipe.
2. It can be adjusted by operating the powder collecting unit 3 up and down.

The powder mixed gas inflow pipe 2 of the powder collecting section 3
A cylindrical peripheral wall 28 continues at the lower part of the facing surface facing to, that is, the lower part of the re-scattering prevention plate 27. The peripheral wall 28 is continuous with the flexible member 29 outside the separation chamber 1. And
The flexible member 29 is located at the bottom of the powder collection unit 3 and is continuous with the bottom storage unit 30 for stacking and storing the powder.
Further, a part of the peripheral wall 28 is provided with an extraction port 5 for extracting a part of the gas sent to the powder collecting part 3 so as to vertically penetrate the peripheral surface of the peripheral wall 28. There is. A tip portion 31 of the bleeding port 5 is open toward the bottom side in the vicinity of the center line of the powder collecting section 3 and is configured to bleed a predetermined bleeding amount l _L from there. . Also, the extraction port 5
Is connected to a required bleeding device outside the device, and as will be described later, it is possible to collect powder efficiently without crushing from the balance of the bleeding amount l _L of the predetermined amount and the exhaust amount l ₀ of the predetermined amount. To be realized. A vibrator 32 for vibrating the powder collecting unit 3 to prevent the powder from adhering is provided on the outer periphery of the powder collecting unit 3.

Here, the operating state of the powder separating apparatus will be described with reference to FIG. 1. First, the powder mixed gas obtained by mixing the powder from the introduction pipe 46 to the powder mixed gas inflow pipe 2 will be described. Is introduced with the downward flow in the vertical direction.
The powder mixed gas is supplied to the powder mixed gas inflow pipe 2 described above.
Flows along the flow direction inside the. Then, at the bottom portion 12 of the powder mixture gas inflow pipe 2 having the inverted conical shape, the flow velocity thereof is accelerated according to the ratio of the diameter d of the opening 13 and the diameter D ₁ of the powder mixture gas inflow pipe 2.

Next, in the powder mixed gas blown out from the opening 13 at the bottom of the powder mixed gas inflow pipe 2, first, the gas component is angled from the vertical direction in the void portion 15, 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. The powder mixed gas thus taken out is used in the separation chamber 1
The exhaust gas is exhausted from the exhaust port 4 provided at a predetermined exhaust amount l ₀ . On the other hand, the powder is made to flow together with the gas up to the opening 13 of the powder mixed gas inflow pipe 2, but is not taken out into the separation chamber 1 due to the action of inertial force and the action of gravity, and goes straight on as it is. Powder intake port 14 of collection unit 3
It rushes into the inside of the powder collection part 3.

In this way, the gas and the powder are separated in the space 15 between the powder mixed gas inflow pipe 2 and the powder collecting section 3, and the powder collecting section 3 collects the rushed powder. However, in the powder separating apparatus of the present embodiment, it is possible to collect while preventing crushing and the like. In other words, the powder that has rushed into the powder collecting unit 3 has a flow rate that is suppressed because the amount of air is such that the gas component is discharged from the extraction port 5, and the condition is close to the condition in which the balance between gravity and the resistance force of the fluid is close. Settles at the terminal settling velocity. Therefore, it is possible to avoid a collision with an impact plate or the like with an impact or a friction that is pressed against a wall or the like, and when powder is powdered milk, it is possible to prevent the powder from being broken or the free fat from increasing. Here, the extraction amount l _L from the extraction port 5 has a constant relationship with the exhaust amount l _0, and the adjustment does not reduce the collection ability. This is because if the extraction amount l _L is too small with respect to the exhaust amount l ₀ , the degree of powder scattering from the collection part increases due to turbulence of the air flow in the powder collection part 3 or the like. To do. When the extraction amount l _L is a problem with respect to the exhaust amount l ₀ , the powder is taken out from the powder pair collection unit 3 through the extraction port 5, and the powder is not collected in the bottom storage unit 30 and is collected. Collective efficiency decreases. Therefore, in the powder separation apparatus of this embodiment, for example, l _L / l ₀ (bleeding rate) is set to approximately 5 to 25%, more preferably 7 to 20%. This improves the collection efficiency.

In addition, the powder mixed gas inflow pipe 2 of the powder collection unit 3
The re-scattering prevention plate 27 provided on the side facing the surface prevents the powder from being taken up into the separation chamber 1 from the inside of the powder collection unit 3. In addition, displacement l ₀ and extraction amount l _L
If the adjustment is not performed properly, turbulence of the air flow in the powder collection unit 3 will occur, but in that case re-scattering can be prevented.

Further, the vibrator 32 provided on the outer peripheral portion of the powder collecting section 3 can prevent the powder from adhering to the powder collecting section 3 in advance.

Next, a powder processing unit constituted by using the powder separating apparatus of this embodiment will be described with reference to FIGS. 2 and 3.

First, a powder processing unit for carrying powder has a structure shown in FIG. 2, for example. FIG. 2 shows a powder processing unit including an air-mixed powder pressure-feeding device. In FIG. 2, a device 40 shown within a broken line is a powder separating device having the above-mentioned configuration. Further, in the present embodiment, the air-mixed powder pressure-feeding device includes the powder supply unit 41, the blower 42, the blower pipe 44, and the introduction pipes 45, 46.
Consists of Initially, the powder is accumulated in the powder supply unit 41, and the powder supply unit 41 is supplied with compressed air. The blower 42 receives the transportation air. The powder supply section 41
The powder accumulated in the blower is fed from the powder supply unit 41 to the blower 42.
Further, it is mixed with the air sent through the blower pipe 44 and passes through the introduction pipe 45 which stands upright in the vertical direction. The powder is the introduction tube
It is supplied to the powder mixed gas inflow pipe 2 of the powder separating apparatus 40 through an introduction pipe 46 having a diameter larger than 45 and having an approximately L shape. Then, in the powder separating apparatus 40, the powder and the gas are effectively separated by the balance between the exhaust amount and the extractor amount, and the trapping such as crushing is realized.

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

In the configuration of FIG. 3, the powder separating device 50 having the above-described configuration is connected to the hot air mixing type powder drying device 51 on the powder mixed gas extraction side. In the powder separating apparatus 50, as described above, the powder and the gas are effectively separated by the balance between the exhaust amount and the extraction amount, and the trapping such as crushing is suppressed. The powder separation device 50 has an exhaust port 4 and an extraction port 5, and the exhaust port 4 and the extraction port 5 are connected to a cyclone collector 52. The powder that is not collected by the powder separating device 50 is discharged from the exhaust port 4 and the extraction port 5, but by connecting the cyclone collector 52 to the exhaust port 4 and the extraction port 5 in this way, It is possible to improve the collection efficiency.

Further, the powder separating apparatus of this embodiment may be modified as shown in FIG. The powder separating apparatus 60 has a configuration similar to that of the above-mentioned powder separating apparatus, and the bottom portion 12 of the powder mixed gas inflow pipe 2 having an inverted conical shape has
An opening 13 is provided, and a powder intake port 14 is provided on the re-scattering prevention plate 27 facing the opening 13 on the powder collection unit 3 side. Then, in the powder separating 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. The auxiliary plate 61 is provided along the peripheral edge 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 separating apparatus of this embodiment will be described. In the experiment, using the powder separation apparatus of this example, Experiment I on collection efficiency and Experiment II on increase in free fat were conducted.

Experiment I First, Experiment I is an experiment relating to powder collection efficiency, and Table 1 shows the relationship between the shape of the opening 13, the distance S between the openings, and the extraction rate.

Regarding Experiment I, the symbols and numbers in Table 1 have the following meanings.

・ Types of raw powder used SM: skim milk, granulated powder with an average particle size of about 100μ WM: whole milk powder, multiple aggregated powder with an average particle size of about 80μ ・ Aperture Shape (*): The powder mixed gas inflow pipe (200 mφ) is cylindrical as it is: The lower half of the powder mixed gas inflow pipe is cylindrical with 100 mmφ: Powder mixing as shown in Fig. 1 About the outlet of the gas inflow pipe
Inverted conical shape of 60 ° (outlet diameter 100 mmφ) The re-scattering prevention plate 27 was a ring-shaped one having the same diameter as the opening diameter. Further, the extraction rate indicated by (-) indicates that the extraction was omitted.

The purpose of this experiment I is to set the optimum conditions of the apparatus used, and the following results were obtained from the data shown in Table 1.

Firstly, in Experimental Examples A to B, the powder mixed gas inflow pipe has a case where d / D ₁ = 1 (remains cylindrical) at its opening, and should be collected as a result. 80% of milk powder
The above shows that the efficiency was extremely low after shifting to the exhaust port.

Secondly, in the embodiment C, the opening is narrowed to form a funnel-shaped opening having a cylindrical guide tube at the tip thereof. As a matter of course, the air velocity increases in the opening. , Shows that the milk powder is re-scattered in the collection part and soars, and the collection efficiency is low.

Thirdly, in Experimental Examples D to V, referring to the above results, the opening was made into an inverted conical shape (α = 60 in FIG. 1).
, D / D ₁ = 1/2), and the diameter of the open part (powder intake port) of the re-scattering prevention plate was 100 mm. In addition, a bleed port that opens downward is provided below the milk powder collecting portion.

Fourthly, in Experimental Examples D to P, three groups of experimental data were obtained in which granular skim milk powder was used as the milk powder material and the separation distance (void area) of the openings was constant. From these data, it was found that there is a relatively strong correlation between the extraction rate and the collection efficiency, and it is necessary to set the extraction rate to about 7 to 20% in order to improve the collection efficiency.

Fifthly, in Experimental Examples Q to V, whole milk powder was used as the milk powder material, and an attempt was made to apply the degreasing-containing powder, which is one of the objects of the present invention, to the prevention of free fat generation. As a result, this experiment confirmed that it was suitable for milk powder-containing milk and that a practical collection efficiency could be expected.

Experiment II This is an experiment for investigating whether or not there is an increase in free fat when powder is separated and collected from a powder mixed gas using this apparatus, and Experimental Example S in Experiment I is adopted as the setting condition.

 The results are shown in Table 2.

Here, the raw material powder used in the experiment II is Example-1: Full-fat milk powder = milk powder concentrated and milk powder that naturally falls into the spray drying chamber (fat content 26.2%) Example-2: Synthetic milk powder = The skim milk is concentrated, vegetable fat is added and homogenized, spray-dried, and the milk powder (content fat 2.85%) of the part naturally dropped into the drying chamber.

Regarding the condition setting of Example-1 and Example-2, (Example-1) 120 kg of raw material milk powder was weighed, lightly mixed and homogenized, and divided into two parts. Pumping device (pneu
The entire amount was supplied to the powder separating apparatus of this example using a matic conveyer) to collect the milk powder.

(B) Furthermore, the exhaust containing the milk powder that could not be collected by this device and the extracted air were combined and sent to a cyclone collector for almost complete recovery.

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

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

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

(Note that the FF value * in Table 2 indicates the free fat content, and the weight of fat extracted by adding carbon tetrachloride to powdered milk and shake-extracted is shown as% of the total weight of powdered milk used. This is based on the free fat measurement method adopted.)) From the above experimental results in Table 2, (A) and (A ′)
It can be seen that the increase in free fat is suppressed in. (Note that the FF values in (A) and (A ') above are lower than the raw powder because the milk powder separated and collected has a different average particle size from the milk powder transferred to the cyclone collector. In other words, in a conventional cyclone collector, powdered milk is pressed against the peripheral wall surface and rubs against it, causing an increase in free fat. However, in the powder separating apparatus of the present embodiment, there is no pressing and friction due to centrifugal force, and the milk powder that has rushed into the powder collecting section 3 is immediately decelerated and accumulates at approximately the terminal sedimentation speed, increasing the free fat. It was found that the quality of powdered milk can be maintained satisfactorily by the prevention and the collision and destruction of powder particles.

As described above, the powder separation device of the present embodiment can separate gas and powder using inertial force, and is crushed by being pressed against a wall or the like by centrifugal force or the like like a conventional device. The problems such as occurrence of noise and continuous processing for a long time cannot be solved. In particular, by adjusting the amount of exhaust gas and the amount of bleed air, collection that prevents crushing of powder and the like is realized. Therefore, in the case of separating the milk powder using the powder separating apparatus of the present embodiment,
The destruction of fat globules can be prevented and the increase of free fat can be suppressed, the destruction of particles can be prevented, and the solubility and dispersibility of powdered milk can be improved. Further, it is suitable for treating powder having adhesiveness.

Needless to say, this device can also be used as a general dust collector. The powder can be applied to powders such as powdered milk which are not easy to handle, and various powdered milks such as infant formula powdered milk, whole milk powder, skim milk powder, and powder cream. Further, it is not limited to powdered milk and can be used for other edible powders, for example, powdered soups, granular powdered foods such as instant coffee, and the like.

Further, the powder separating apparatus and the powder processing unit of the present invention can be variously modified without departing from the gist of the present invention.

〔The invention's effect〕

By applying the powder separating apparatus of the present invention to the powder separating step, it is possible to prevent crushing and friction of the powder, and especially to prevent the generation of free fat in the milk powder containing fat, and to stabilize the quality. It is possible to secure the sex. Further, it is possible to handle powders having adhesive properties, and continuous treatment for a long time is possible. Further, by using the above-mentioned powder separation device in the powder processing unit, it is possible to obtain a preferable effect of powder separation.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an example of the powder separation device of the present invention, FIG. 2 is a partially cutaway side view for explaining an example of the powder processing unit of the present invention, and FIG. 3 is a powder processing 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 a technique prior to the powder separation device of the present invention. Further, FIG. 5 is a cross-sectional view of essential parts for explaining a modified example of the powder separating apparatus of the present invention. 1 …… Separation chamber 2 …… Powder mixed gas inflow pipe 3 …… Powder collection part 4 …… Exhaust port 5 …… Bleed port 13 …… Opening part 14 …… Powder intake port 15 …… Gap

Claims (9)

(57) [Claims] 1. A separation chamber provided with an exhaust port for exhausting a predetermined exhaust amount, and a cylindrical shape protruding inward from an upper surface of the separation chamber, having an inverted conical shape, and having an opening formed at the bottom. A powder mixed gas inflow pipe, and a powder intake port that is separated from the opening of the powder mixed gas inflow pipe inside the separation chamber and has a diameter substantially the same as the opening, and It has a tubular powder collecting part provided with a bleeding port for bleeding a predetermined bleeding amount, and the gas content of the powder mixed gas is the powder in the space between the opening and the powder intake. After the powder separated into the separation chamber at an angle from the centerline direction of the body mixture gas inflow pipe and the powder separated in the void portion protrudes into the powder collection unit, the exhaust amount and the extraction amount are adjusted to substantially end the powder. A powder separation device characterized by settling at a settling speed. 2. The powder separating apparatus according to claim 1, wherein the powder mixed gas inflow pipe has a vertical axis. 3. The powder separating apparatus according to claim 1, wherein the open end of the extraction port is opened downward. 4. The powder separating apparatus according to claim 1, wherein a re-scattering prevention plate is installed on the upper end of the powder collecting section. 5. The distance between the openings of the powder mixed gas inflow pipe and the powder intake of the powder collector is adjustable so that the distance can be adjusted. Item 1. The powder separation device according to item 1. 6. The outer peripheral side of the bottom of the powder mixed gas inflow pipe,
The powder separating apparatus according to claim 1, further comprising an auxiliary plate. 7. The powder separation according to claim 1, wherein the gas exhausted from the exhaust port and the gas extracted from the extraction port join together and are connected to the cyclone collector. apparatus. 8. A separation chamber provided with an exhaust port for exhausting a predetermined exhaust amount, and a cylindrical shape protruding inward from the upper surface of the separation chamber, having an inverted conical shape, and having an opening formed at the bottom. A powder mixed gas inflow pipe, and a powder intake port that is separated from the opening of the powder mixed gas inflow pipe inside the separation chamber and has a diameter substantially the same as the opening, and It has a tubular powder collecting part provided with a bleeding port for bleeding a predetermined bleeding amount, and the gas content of the powder mixed gas is the powder in the space between the opening and the powder intake. After the powder taken out into the separation chamber at an angle from the center line direction of the body mixed gas inflow pipe and rushed into the powder collecting portion after the powder separated in the void portion is adjusted, the exhaust gas amount and the bleed air amount are adjusted to substantially end. It has a powder separator that settles at a settling speed, and the powder separator is an air-mixed powder. Powder processing unit is provided continuously to the powder mixture gas extraction side of feeder, for conveying the powder. 9. A separation chamber provided with an exhaust port for exhausting a predetermined exhaust amount, and a cylindrical shape protruding inward from an upper surface of the separation chamber and having an inverted conical shape with an opening formed at the bottom. The powder mixed gas inflow pipe and the powder intake port which is separated from the opening of the powder mixed gas inflow pipe inside the separation chamber and has substantially the same diameter as the opening are provided so as to correspond to each other. It has a tubular powder collecting part provided with a bleeding port for bleeding a predetermined bleeding amount, and the gas content of the powder mixed gas is the powder in the space between the opening and the powder intake. After the powder taken out into the separation chamber at an angle from the center line direction of the body mixed gas inflow pipe and rushed into the powder collecting portion after the powder separated in the void portion is adjusted, the exhaust gas amount and the bleed air amount are adjusted to substantially end. It has a powder separator that settles at a settling speed, and the powder separator is a hot air mixing type powder. And continuously to the powder mixture gas extraction side of the drying device, a powder processing unit for separation of the powder.