JP4176649B2 - Operation control method of vibration dryer - Google Patents

Description

  The present invention relates to an apparatus for performing processing such as mixing, drying, granulation, coating, and the like while flowing powder particles by vibrating a container-shaped processing chamber, and in particular, more delicate drying processing is efficient. The present invention also relates to a vibration dryer operation control method that can be carried out economically.

In manufacturing plants, processing plants, etc. for powders of foods, pharmaceuticals, agricultural chemicals, feeds, chemicals, etc., these raw materials are obtained by subjecting the raw materials to mixing, drying, granulation, coating, etc. There is a vibration processing device as one of the devices for this purpose. This equipment can perform processing such as drying, mixing, granulation, coating, etc. on the workpiece under reduced pressure or normal pressure, and can also treat the workpiece containing flammable solvent. To do.
As shown in FIG. 8, the basic configuration of a vibration dryer D ′ to which this type of apparatus is applied is a processing chamber 10 ′ in a hermetic cylindrical container-like casing 1 ′, and this casing 1 ′. Is provided on a base B 'with an elastic body 2' such as a spring or vibration-proof rubber interposed, and a vibrator unit 5 'is provided on the casing 1'. And the granular material G which is a to-be-processed object is made to stay in the processing chamber 10 'in the flowed hopping state by the vibration force generated by the vibrator unit 5', and the granular material group G is included in the processing chamber 10 '. The part that receives conduction heat from the wall is constantly updated to achieve uniform drying.

The vibration condition of the casing 1 'is usually determined so as to obtain a good flow state with emphasis on the drying efficiency, and is generated by the vibrator unit 5' in accordance with the properties and amount of the object to be processed. The vibration frequency and amplitude of the treatment chamber 10 'to be selected are selected.
However, since the properties of the object to be processed change with the progress of drying, there are cases where a good fluid state cannot be obtained at the initial set value. In addition, there is a case where it is not desired to destroy the particle shape by suppressing vibration damage as much as possible, for example, to obtain a softer dry product. In these cases, the vibration conditions are changed in order to avoid the occurrence of uneven drying and a decrease in the drying speed.

By the way, depending on the properties of the object to be processed, a so-called lump may be generated, and such a lump has a so-called dry-up state in which the drying of the surface has progressed, so that the inside is extremely dried. It becomes difficult to proceed, and the drying processing time is greatly increased.
As an operation method for preventing the formation of the lump, the flow state of the granular material G group is changed by intermittently vibrating the housing 1 '(for example, Patent Document 1). reference). However, such a method places a heavy burden on the apparatus and may cause damage to the flexible pipe F ′ connected to the exhaust port 17 ′ and the pipes and wiring connected to the heat medium nozzle 14 ′. .
This is derived from the structure of the vibration dryer D ′, which causes resonance when the natural frequency of the device (housing 1 ′) matches the frequency of the forced vibration by the vibrator unit 5 ′. As a result, the vibration has a very large amplitude compared with that during steady operation (the amplitude during steady operation is several mm or less, whereas the amplitude during resonance is ten or more mm). This will cause damage to the connection site and the like.
In particular, when the casing 1 'is vibrated intermittently, the vibration unit 5' is activated and the rotational speed is increased, and the vibrator unit 5 'is stopped and the rotational speed is decreased twice. Since it passes through the resonance frequency range, resonance is caused many times in proportion to the number of intermittent operations. In addition, an excessive force is applied to the object to be processed at the time of resonance, so that the particle shape may be damaged or the surface state of the particles may be modified.

In order to suppress such resonance, it is possible to install a viscous damping mechanism such as a damper. However, if the damping characteristic is not reduced at a frequency other than the resonance frequency, the original function of the device cannot be exhibited. As a result, the structure of the damping mechanism becomes complicated, resulting in an increase in cost.
Further, when the intermittent operation described above is performed, the operator misunderstands that the drying has been completed when the vibration is stopped, and the discharge port 16 ′ is opened, and the granular material G that is being dried is discharged. Is also expected to occur.

JP 2002-130953 A

  The present invention has been made in view of such a background, and the resonance of the housing is suppressed to a minimum number of times to avoid damage to the apparatus, as well as breakage of the particle shape and modification of the surface state of the particle. Development of a new vibration dryer operation control method that can avoid the generation of lumps and lumps and can perform more delicate drying processing efficiently and economically is a technical problem.

That is, the operation control method of the vibration dryer according to claim 1 includes a housing having an internal space as a processing chamber in a state where an elastic body is interposed on a base, and the housing is vibrated by a vibrator unit. , in flowing workpiece which has been introduced into the processing chamber, in operation of the apparatus for performing the drying process of the object to be processed, said housing, which is vibrated at a frequency above the resonant frequency, the object to be processed In the initial stage of the drying process of the object, the casing is vibrated at a frequency near the resonance frequency for stationary drying, and then the frequency is changed as needed within a certain frequency range equal to or higher than the resonance frequency. It consists of.
According to the present invention, the casing can be vibrated in a plurality of types of vibration modes by changing the vibration frequency of the casing, and the object to be processed repeatedly flows and stays on the heat transfer surface. Generation | occurrence | production can be avoided and a more delicate drying process can be performed. Further, in order to minimize the occurrence of resonance vibration, damage to the connecting member, destruction of the particle shape, and modification of the particle surface state can be avoided.
In addition, the processed material can be dried without adding a share at the initial stage of drying, and then fluidized when the strength of the processed material is improved and the strength is improved. Even when handling raw materials that are likely to cause reforming or formation of lumps, a good dry product can be obtained.

The operation control method of the vibration dryer according to claim 2 is characterized in that in addition to the requirement, the amplitude is changed in addition to the frequency.
According to the present invention, it is possible to more effectively avoid the formation of a lump and perform a more delicate drying process.
The above problems can be solved by using the configuration of the invention described in each of the claims as a means.

  According to the present invention, since resonance of the housing is not inadvertently induced, damage to the apparatus can be avoided, and particle shape destruction, particle surface modification, and generation of agglomerates are avoided. Thus, a delicate drying process can be performed efficiently and economically.

  Hereinafter, the operation control method of the vibration dryer of the present invention will be specifically described based on the illustrated embodiment. It should be noted that technical modifications can be made to this embodiment within the technical scope of the present invention.

Hereinafter, the configuration of the vibration dryer D to which the present invention is applied will be described, and then the operation control method of the vibration dryer of the present invention will be described together with the operation mode of this apparatus.
What is indicated by a symbol D in the figure is a vibration dryer, which places a casing 1 having an internal space as a processing chamber 10 on a base B with an elastic body 2 interposed therebetween. 1 includes a vibrator unit 5 with respect to a base 3 attached to 1. The vibration dryer D is provided with a condenser, a vacuum aggregating device 6 including a vacuum pump, and a heat medium circulator 7 as peripheral devices. The inside of the processing chamber 10 is evacuated and heated. While the casing 1 is vibrated by the vibrator unit 5, the heat treatment is performed by applying conduction heat from the inner wall of the processing chamber 10 to the powder G that is the object to be processed.

Hereinafter, various members constituting the vibration dryer D will be described in detail.
First, the base B will be described. As an example, as shown in FIGS. 1 and 2, the base B is configured by appropriately combining steel materials, and four support pillars C stand on the base B. Established. The elastic body 2 is a columnar member formed of an elastic member such as a spring or a vibration-proof rubber, and is provided on the support column C.

Next, the case 1 will be described. This is a horizontal cylindrical member having an internal space as a processing chamber 10, and fixed legs 11 are formed on the side periphery of the case 1, and both cylindrical openings are provided. A side plate 12 is provided to be freely opened and closed.
A jacket inner plate 13 is provided on the side of the casing 1 and the side plate 12, and a heat medium nozzle 14 is further attached to the heat medium nozzle 14, and a heat medium circulator 7 such as hot water is connected to the heat medium nozzle 14.
When granulation / coating is performed using the vibration dryer D, a nozzle for spraying a binder liquid and a coating liquid is provided at appropriate positions on the casing 1 and the side plate 12.

  In addition, an inlet 15 is formed in the side periphery of the housing 1, a discharge port 16 is formed in the side plate 12 located on the opposite side, and an exhaust port 17 is formed in the approximate center of the housing 1. The vacuum aggregation device 6 is connected to the exhaust port 17 using a flexible pipe F or the like. In addition, a measurement port 18 is formed at an appropriate location of the housing 1, and a temperature sensor, a humidity sensor, and the like connected to an appropriate control panel (not shown) are attached to the measurement port 18. The discharge port 16 is opened and closed by a lid body 16a. The lid body 16a approaches and separates from the discharge port 16 by operating a handle 16c provided in the duct 16b. Further, a drain port 19 is formed in the lower part of the housing 1. In this embodiment, the processing chamber 10 is installed on the base B in a state where the discharge port 16 side is inclined downward by 1 to 2 ° with respect to the horizontal line.

  As shown in FIG. 1, a T-shaped base 3 is fixed to the lower part of the outer periphery of the housing 1 in a side view, and two vibrator units 5 are fixed to the base 3. In this embodiment, the base 3 is attached to substantially the center of the casing 1 in the longitudinal direction, the vibrator unit 5A is attached to the surface of the base 3 on the inlet 15 side, and the vibrator is attached to the surface on the outlet 16 side. Unit 5B is attached.

As shown in FIG. 3, the vibrator unit 5 includes an armature in a cylindrical casing 50 to form an electric motor 51, an unbalanced weight 53 with respect to the rotating shaft 52, and the unbalanced weight 53. Is covered with a cover 54, and a pedestal 55 having a bolt hole is fixed to the casing 50.
FIG. 3 shows a unit of a type in which the rotating shaft 52 protrudes from both sides of the casing 50 and unbalanced weights 53 are attached to both ends of the rotating shaft 52, but only one unbalanced weight 53 is shown. You may make it employ | adopt the type of unit provided. 3 shows a type of unit in which the rotating shaft 52 is orthogonal to the longitudinal direction of the housing 1, but a unit of the type in which the rotating shaft 52 is orthogonal to the width direction of the housing 1 may be used.

In the vibration dryer D configured as described above, as shown in the plan view of FIG. 4A, the rotating shaft 52 is directed to the transfer path of the workpiece (the path from the inlet 15 to the outlet 16). Thus, the vibrator unit 5A and the vibrator unit 5B are attached to the housing 1 so as to be orthogonal to each other. Therefore, the vibration force generated by the vibrator unit 5 changes its direction in the longitudinal section of the housing 1 as shown in FIGS.
Further, the vibrator unit 5A is located closer to the elastic body 2 located on the insertion port 15 side than the elastic body 2 located on the discharge port 16 side. On the other hand, the vibrator unit 5B is located closer to the elastic body 2 located on the discharge port 16 side than the elastic body 2 located on the insertion port 15 side.

  Here, when the rotation direction of the vibrator unit 5 is defined, in the side view shown in FIG. 5, counterclockwise rotation is defined as normal rotation, and the opposite, that is, clockwise rotation is defined as reverse rotation. Moreover, about the transfer direction of the granular material G, the direction which goes to the discharge port 16 side from the injection port 15 side is made into a normal direction, and the opposite, ie, the direction which goes to the injection port 15 side from the discharge port 16 side, is defined as a reverse direction.

Then, by changing the rotation direction and the operation stop state of these vibrator units 5A and 5B, the mode of the generated vibration force is changed. First, as shown in FIG. When only the vibrator unit 5B located in the position is started in the normal rotation and the other vibrator unit 5A is stopped, a vibration mode in which the object to be processed proceeds at a high speed in the positive direction is obtained.
Further, as shown in FIG. 5B, when only the vibrator unit 5A located near the insertion port 15 is activated in the forward direction and the other vibrator unit 5B is stopped, the object to be processed is in the positive direction. A vibration mode that travels at a low speed can be obtained.
Furthermore, as shown in FIG. 5 (c), when only the vibrator unit 5A located near the insertion port 15 is activated by reverse rotation and the other vibrator unit 5B is stopped, the workpiece is reversed. A vibration mode traveling at a high speed in the direction is obtained.
Furthermore, as shown in FIG. 5 (d), when only the vibrator unit 5B located near the discharge port 16 is activated by reverse rotation and the other vibrator unit 5A is stopped, the workpiece is reversed. A vibration mode that travels at a low speed in the direction is obtained.

  The natural frequency (resonance frequency) of the casing 1 shown in this embodiment is about 9.3 Hz as shown in the graph of FIG. 7, and the amplitude increases as the frequency of the forced vibration by the vibrator unit 5 approaches the resonance frequency. It gradually increases and reaches the maximum amplitude when the natural frequency and the frequency of the forced vibration coincide.

The vibration dryer D to which the present invention is applied is configured as described above as an example. Hereinafter, the operation control method of the vibration dryer according to the present invention will be described together with the operation mode of the vibration dryer D. explain.
(1) Setting of apparatus Prior to the operation of the vibration drier D, both openings of the housing 1 are closed by the side plate 12, and the discharge port 16 is closed by the lid 16a.
Further, the pressure in the processing chamber 10 is set by the vacuum aggregating device 6 (2.3 kPa in this embodiment), and the temperature (70 ° C. in this embodiment) and the flow rate of the heat medium circulated by the heat medium circulator 7 are set. .
Further, the number of rotations of the vibrator unit 5 is set according to the shape, particle size, weight, and the like of the powder G that is the object to be processed, and the vibration period and amplitude are set. In this embodiment, the casing 1 is vibrated at a frequency equal to or higher than the resonance frequency (9.3 Hz), and this frequency is changed as needed within a range of 9.7 to 19.5 Hz as an example. As for the amplitude, as shown in the graph of FIG. 7, it fluctuates with a change in frequency.

(2) Initial drying (stationary drying)
Then, the vacuum agglomeration device 6 is activated to bring the inside of the processing chamber 10 into a vacuum state, the heat medium circulator 7 is activated to start circulation supply of the heat medium, and the vibrator unit 5 is activated to activate the casing 1. It vibrates and throws in the granular material G (crystalline cellulose as an example).
Here, as shown in FIG. 6A, the casing 1 is oscillated at a frequency near the resonance frequency (10 Hz as an example) to perform stationary drying, and the powder G group is a heat transfer surface. The processing chamber 10 is heated without leaving the wall, and drying proceeds without adding shear. For this reason, drying can be performed without causing particle destruction of the granular material G and surface modification, and preventing dryness.

(3) Steady drying Next, when the water content of the powder G is lowered to a desired value, the powder G is flown into the processing chamber 10 in a hopping state as shown in FIG. It is made to stay and the part which the granular material G group receives conduction heat from the wall among the processing chambers 10 is updated continuously, and uniform drying is aimed at.
At this time, by changing the vibration frequency of the casing 1 at any time within a range of 9.7 to 19.5 Hz, the flow mode of the powder G group is also changed at any time. Since it repeats, the production | generation of a lump can be prevented effectively.
The water vapor generated by such drying reaches the vacuum aggregating device 6 from the exhaust port 17 and is appropriately discharged to the outside.

(4) Discharging operation When it is detected by a temperature sensor or the like that the moisture content of the granular material G eventually becomes a desired value, or when a preset processing time has elapsed, FIG. As shown in c), the discharge port 16 is opened and the granular material G is discharged.

As described above, according to the present invention, the resonance generated in the vibration dryer D can be suppressed to the minimum number of times only at the time of starting and at the time of stopping. It is possible to avoid damages such as connection sites and wiring locations.
In addition, since resonance does not occur in the state where the powder G is located in the processing chamber 10, excessive force is not applied to the powder G to cause particle destruction or surface modification.

It is a side view which shows the vibration dryer to which this invention is applied. It is a front view and back view same as the above. It is a disassembled perspective view which shows a vibrator unit. It is the top view, side view, and front view for demonstrating the action direction of the vibration force produced by a vibrator unit. It is a side view for demonstrating the mode of the vibration force produced by a vibrator unit. It is a skeleton side view for explaining the operation control method of the present invention step by step. It is a graph showing the relationship between the frequency and amplitude of a housing. It is a side view which shows the damage of the apparatus by the conventional driving | operation operation of a vibration dryer, and the destruction state of a to-be-processed object.

Explanation of symbols

D Vibration dryer 1 Case 10 Processing chamber 11 Fixed leg 12 Side plate 13 Jacket inner plate 14 Heat medium nozzle 15 Input port 16 Discharge port 16a Lid 16b Duct 16c Handle 17 Exhaust port 18 Measurement port 19 Drain port 2 Elastic body 3 Base DESCRIPTION OF SYMBOLS 5 Vibrator unit 5A Vibrator unit 5B Vibrator unit 50 Casing 51 Electric motor 52 Rotating shaft 53 Unbalance weight 54 Cover 55 Base 6 Vacuum aggregation apparatus 7 Heat medium circulator B Base C Support pillar F Flexible pipe G Granule

Claims (2)

A casing having an internal space as a processing chamber is provided in a state where an elastic body is interposed on the base, and the casing is vibrated by a vibrator unit, so that the processing object put into the processing chamber flows. In the operation of the apparatus for drying the object to be processed, the casing is vibrated at a frequency equal to or higher than the resonance frequency. In the initial stage of the drying process of the object to be processed, the casing is A method for controlling the operation of a vibration dryer, characterized in that it is subjected to stationary drying by vibrating at a nearby frequency, and thereafter, the frequency is changed as needed within a certain frequency range above the resonance frequency .   2. The vibration dryer operation control method according to claim 1, wherein the amplitude is changed in addition to the frequency.

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