JPH08155203A - Centrifugal spray for spray drier - Google Patents

Abstract

PURPOSE: To make the required power for a centrifugal spray small and achieve the energy saving. CONSTITUTION: A secondary spray disk 19 with a number of secondary spray holes 19c, 19c... on its peripheral wall is journaled in a high temperature atmosphere jetting from a hot air jet device and rotated at a proper speed with a secondary drive motor 28. A primary spray means consisting of spray nozzles 17 or a primary spray disk for generating primary fog of a raw liquid to be dried toward the secondary spray holes 19c is constituted on the inner diameter side of the secondary spray disk 19. While the secondary spray disk 19 is rotated, the raw liquid to be dried is fed to the primary spray means to dry secondary fog of the raw liquid to be dried sprayed out of the secondary spray holes 19c of the secondary spray means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a rotary disc type spraying device, and more particularly to a centrifugal spraying device for a spray drying device which can achieve energy saving of required effect.

[0002]

2. Description of the Related Art Conventionally, an undiluted solution to be dried is sprayed at a high pressure onto the surface of a rotating disk of a centrifugal sprayer installed in the central portion of the ceiling of a drying chamber, which is rotationally driven at high speed, and is dispersed in high temperature air for drying for an instant. A rotary disk type spray dryer having a structure for drying is used. That is, as shown in FIG. 7, this type of centrifugal sprayer supplies from a pump (not shown) to a liquid raw material supply pipe 53 formed in a pocket 52 of a spray rotary disc 51 mounted on a rotary shaft 50. While supplying the dried undiluted solution, the rotary shaft 50 is rotated at a high speed, and the undiluted solution is directly fed in one stroke through a large number of spray holes 54, 54 ... It has a centrifugal force spraying method.

Originally, the quality of the dried product obtained by this type of spray dryer is about 97, except for special ones.
% Is irrelevant to the shape of the spray disk 51, and is mostly due to the peripheral speed of the rotating disk. The focus of the rotating disk 51, which is generally most often used, is about 90 m.
/ Sec, for example, in the case of ramen soup (name of undiluted liquid to be dried), concentration 40%, liquid specific gravity 1.1, liquid temperature 60
° C, stock solution treatment capacity of 1.000 Kg / hour, the diameter of the rotating disk 51 is 180 mm, the rotation speed is 410,000.
rpm, the peripheral speed is 90 m / sec, and the required horsepower of the motor for driving the rotating shaft 50 at this time is 11 Kw.
Is. Then, under the above conditions, the stock solution throughput is 5.00
At 0 Kg / hour, the required horsepower of the motor reaches 22 Kw.

As described above, this type of centrifugal sprayer is required to operate at a high speed, and therefore has a drawback that it consumes a great amount of power.

Further, in the conventional spray dryer, the rotating disk 5
Since the rotary shaft 50 for rotating 1 is located at the center of the rotary disk 51, the installation position of the liquid concentrate supply pipe 54 to be dried must be provided at a position deviated from the rotary center, and the rotary disk is rotated. There is a problem that the contact radius with 51 becomes short and the drying efficiency is poor.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and enables low-speed rotation spraying without lowering the drying treatment capacity, which is different from the conventional high-speed rotation spraying method. It is an object of the present invention to provide a centrifugal sprayer for a spray dryer, which can reduce the required power of the sprayer and achieve energy saving.

[0007]

A centrifugal sprayer for a spray dryer according to the present invention is a centrifugal sprayer for a spray dryer for supplying an undiluted solution to be dried into a high-temperature dry air atmosphere for drying treatment. In addition to axially arranging a secondary atomizing disk having a large number of secondary atomizing holes formed in the peripheral wall in a dry air atmosphere so as to be rotationally driven at an appropriate peripheral speed by an external rotational drive device,
On the inner diameter side of the secondary spraying disc, primary spraying means for generating a primary mist of the stock solution to be dried toward the secondary spraying hole is constituted,
While rotating the secondary spraying disc, the stock solution to be dried is supplied to the primary spraying means, and the secondary mist of the stock solution to be dried discharged from the secondary spraying holes of the secondary spraying means is dried. To do.

The primary spray means is a spray nozzle,
Alternatively, it can be realized by a disk for primary spraying, and the primary spraying means is preferably arranged concentrically with the disk for secondary spraying.

[0009]

The centrifugal sprayer for the spray dryer having the above-described structure is configured such that the secondary spraying disc having a large number of secondary spraying holes formed on the peripheral wall thereof is rotationally driven, and the primary spraying nozzle or the primary sprayer is formed on the inner diameter side thereof. The primary mist of the stock solution to be dried is ejected from the disk to the secondary spray hole. Therefore, when the primary mist passes through the secondary spray holes that are rotationally displaced at an appropriate peripheral speed by centrifugal action, it becomes a secondary mist with an ultrafine particle size and is discharged into a high-temperature dry air atmosphere, The heat exchange is instantaneously carried out to evaporate the water, and the stock solution is dried and powdered.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a centrifugal sprayer for a spray dryer according to the present invention will be described below with reference to the drawings.

FIGS. 1 to 3 show a first embodiment. As shown in FIG. 3, the centrifugal sprayer 1 of the present invention is continuous with the upper edge of the inverted conical hopper 3 which constitutes a drying chamber. An annular hot-air jetting device 4 fixed to the upper wall 2a so as to be located on the central axis CL of the cylindrical portion 2 and formed on the lower surface of the upper wall.
The annular hot air blowout port of the hot air jetting device 4 and the secondary spraying section of the centrifugal sprayer 1 are provided so as to face each other in the lower side of the annular shape. A hot gas supply port 5 for drying is opened on one side of the hot air blowing device 4, and an exhaust pipe communicating with the outside of the drying chamber is provided above the discharge port 6 formed at the lower end of the hopper 3. 7 has been opened.

The centrifugal spraying machine 1 has a bottomed cylindrical main body 8 having an end plate 11 fixedly mounted on the upper end thereof via upper and lower bearings 12, 12 pivotally mounted on the end plate 11 and a support bracket 13. The rotary tube shaft 9 is rotatably inserted in the axial center position, and the pulley 26 is axially attached to the upper end of the rotary tube shaft 9.
And a pulley 27 axially attached to an external rotation drive device such as a secondary disk drive motor 28 are rotatably connected via an endless belt. An oil seal 24 is formed outside the upper bearing 12, and the bearing 12 and the oil seal 2
The rotary pipe shaft 9 is rotatably sealed by the seal oil pressure supplied from the oil supply port 20 opened between the four, and the bottom wall of the bottomed cylindrical main body 8 is provided outside the lower bearing 12. Draining edge 1 to be extrapolated to the draining collar 15 protruding from the
An oil draining nut 14 having 4a is fastened, and the oil draining nut 14 rotates in cooperation with the rotary pipe shaft 9 to seal the shaft. The inner cavity of the bottomed cylindrical main body 8 forms an oil sump 16, and the oil suction pipe 21 is inserted from the vicinity of the lower end of the oil sump 16 to the outside of the bottomed cylindrical main body 8 through the end plate 11. It becomes.

Reference numeral 19 is a hollow disk-shaped secondary spraying disk axially attached to the lower end of the rotary tube shaft 9, and is a spraying disk body 1
The upper surface of 9a is covered with a cover plate 19b, the rotary tube shaft 9 is opened in the inner cavity, and a large number of secondary spray holes 19c, 19c arranged side by side in the circumferential direction are formed in the peripheral wall of the spray disk body 19a. Set up. In addition, the lower end of the liquid raw material supply inner pipe 10 inserted from the upper end of the rotary pipe shaft 9 to the axial center position is opened in the inner cavity of the secondary spraying disc 19.

Reference numeral 18 is a primary spray nozzle head screwed and fixed to the lower end of the liquid raw material supply inner tube 10, and a plurality of primary spray nozzles 17 projecting horizontally from the primary spray nozzle head 18, .. 17 communicate with the liquid raw material supply inner pipe 10.

Reference numeral 22 is a sealing O-ring, and 29 is a continuously variable transmission controller for controlling the rotation speed of the secondary disk drive motor 28.

In the centrifugal atomizer 1 having the above-mentioned structure, the seal oil is supplied from the oil supply port 20, and the seal oil staying in the oil sump 16 is discharged and circulated through the oil suction pipe 21. , 12 are maintained in function, and the secondary disk drive motor 28 rotates the rotary tube shaft 9 via the pulleys 26, 27 at a predetermined rotation speed, while supplying the raw material liquid to be dried from the inner tube 10 for supplying liquid material. It is a thing.

At this time, the hot air jetting device 4 provided at the upper end of the drying chamber 2 jets a dry high-temperature gas toward the vicinity of the secondary spraying disc 19, and the secondary spraying disc 19 is exposed. It mixes with the atomized liquid particles ejected from the secondary spray holes 19c, 19c ... And heat is exchanged with the high temperature gas body instantaneously to evaporate the water content and dry powder the stock solution.

The primary spray nozzles 17, 17 ...
The mist-like liquid droplets ejected from the primary spray form an ideal spray structure that can be linearly supplied toward the secondary spray holes 19c, 19c, ... Of the secondary spray disk 19 located immediately before. When the primary mist formed by the nozzle 17 passes through the secondary spray hole 19c, a secondary mist having a finer particle size is formed, and in combination with the centrifugal spraying action by the rotation of the secondary spray disk 19. As a result, a secondary mist having an ultrafine grain size can be obtained.

Next, FIGS. 4 and 5 show a second embodiment of the present invention. The structure different from that of the first embodiment will be described. The inner pipe for supplying liquid raw material 10 has a concentric rotary shaft rotatably inserted into the rotary pipe shaft 9 through the oil-impregnated metal 31, 31. The upper end is rotatably connected to a raw material supply side pipe (not shown) through a rotary pipe joint 30. In the inner tube 10 for supplying liquid raw material, a pulley 32 pivotally mounted near the upper end portion and a pulley 34 pivotally mounted on a primary disk drive motor 33 are pivotally connected by an endless belt, and by a continuously variable transmission controller 35. The rotation speed of the primary disk drive motor 33 is controlled. A disk 47 for primary spraying is fixedly provided on the lower end of the inner tube 10 for supplying liquid raw material, is positioned in the inner space of the disk 19 for secondary spraying, and is rotatable, and the disk for primary spraying is used. A large number of primary spray holes 47a, 47a, which are formed in the peripheral wall of the disk 47 and communicate with the inner tube 10 for supplying liquid raw material, have the same level as the secondary spray holes 19c of the disk 19 for secondary spray. It will be arranged.

In the second embodiment, the secondary disk drive motor 28 is driven to rotate the secondary spraying disk 19 while simultaneously driving the primary disk drive motor 33 to rotate the rotary pipe joint 30.
The undiluted liquid to be dried is supplied to the inner tube 10 for supplying a liquid raw material via the. At this time, the secondary disk drive motor 28 and the primary disk drive motor 33 are rotationally driven so that the secondary spray disk 19 and the primary spray disk 47 rotate in opposite directions.

The stock solution to be dried, which has been supplied to the rotating disk for primary spraying 47 via the inner tube 10 for supplying a liquid material, is discharged radially from a large number of primary spray holes 47a, 47a. Forming fog. At this time, a large number of secondary spray holes 19c formed in the secondary spray disk 19 rotating in the opposite direction on the outside of the primary spray disk 47,
.. 19c ... are opposed to each other, the primary mist is further centrifugally sprayed when passing through the secondary spray hole 19c, and the relative speed of both spraying disks 19 and 49 is increased, so that the secondary mist having a very small particle size is used. The next fog is formed. Then, the secondary mist comes into contact with the high temperature gas jetted from the hot air jetting device 4 and heat is instantaneously exchanged, and the water is evaporated to be a dry powder.

According to the present invention, the secondary atomizing disc 19 is used.
Since the object of the invention is achieved by forming the primary spraying means on the inner diameter side of the secondary spraying hole 19c formed in the secondary spraying hole 19c, as shown in FIG.
Of the spray disc body 19a of the rotary shaft 36 instead of the rotary pipe shaft 9
It is axially attached to the lower end of the spray disc body 19a and has a pocket 1
Liquid raw material supply pipe 3 having primary spray nozzle 37 at 9d
8, the primary spray nozzle 37 is connected to the primary spray hole 19c,
It is also possible to have a configuration facing 19c.

[0023]

As described above, according to the structure of the centrifugal sprayer for a spray dryer according to the present invention, the secondary mist is further secondary by the centrifugal action of the secondary atomizing disk which is formed in front of the injected primary mist. By adopting the double spray structure that forms a mist, the particle size of the stock solution to be dried, which comes into contact with the high temperature gas, can be made ultrafine, and the drying process can be efficiently performed. Further, according to the configuration of the present invention, since the supply position of the liquid to be treated with respect to the secondary spraying disc is located at the rotation center, the secondary spraying disc ideally functions for centrifugal spraying. Therefore, the centrifugal spraying machine of the present invention can be implemented even if the rotation speed of the secondary spraying disk is relatively slow, and the rotation speed of the rotation drive motor can be reduced, so that the motor It is possible to save energy and reduce the size of the device at the same time. Furthermore, it is characterized by improving the working environment because it is possible to reduce the noise during the operation of the device accompanying the low speed operation,
The effect of the present invention is extremely large.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a first embodiment of a centrifugal atomizer according to the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part of the centrifugal sprayer.

FIG. 3 is a schematic vertical cross-sectional view of a spray dryer equipped with the centrifugal sprayer.

FIG. 4 is a vertical sectional view showing a second embodiment of the centrifugal sprayer according to the present invention.

FIG. 5 is an enlarged sectional view of a main part of the centrifugal sprayer.

FIG. 6 is an enlarged cross-sectional view of an essential part showing a third embodiment of the centrifugal sprayer according to the present invention.

FIG. 7 is an enlarged cross-sectional view of a main part showing a conventional centrifugal sprayer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Centrifugal sprayer 4 Hot-air jetting device 8 Bottomed cylindrical main body 9 Rotating pipe axis 10 Liquid raw material supply inner pipe 15 Drain collar 16 Oil drain nut 17 Primary spray nozzle 18 Primary spray nozzle head 19 Secondary spray disk 19c 2 Secondary spray hole 24 Oil seal 28 Secondary disk drive motor 30 Rotating pipe joint 33 Primary disk drive motor 36 Rotation shaft 37 Primary spray nozzle 38 Liquid material supply pipe 47 Primary spray disk 47a Primary spray hole

Claims (4)

[Claims] 1. A centrifugal sprayer for a spray dryer for supplying an undiluted solution to be dried into a high-temperature dry air atmosphere for drying treatment, wherein a large number of secondary spray holes are formed in a peripheral wall in the high-temperature dry air atmosphere. The secondary spraying disc is rotatably driven by an external rotary drive device at an appropriate peripheral speed, and the primary mist of the stock solution to be dried is directed toward the secondary spraying hole on the inner diameter side of the secondary spraying disc. To supply the stock solution to be dried to the primary spraying means while rotatably driving the secondary spraying disk, and to discharge the stock solution to be dried released from the secondary spraying holes of the secondary spraying means. A centrifugal atomizer for a spray dryer, which is characterized in that the next mist is dried. 2. The primary spray means is a spray nozzle,
2. The centrifugal dryer for a spray dryer according to claim 1, wherein the stock solution to be dried is fed from the liquid raw material supply pipe communicating with the spray nozzle by an external pressure feeding means to spray the primary mist toward the secondary spray holes. Atomizer. 3. A liquid raw material supply pipe communicating with the primary spraying means is provided by penetrating through a shaft of a rotary pipe shaft on which a secondary spraying disc is installed, and a spray nozzle is provided as the secondary spraying disc. The centrifugal sprayer for a spray dryer according to claim 2, wherein the centrifugal sprayer is arranged in a concentric position. 4. The primary spraying means is a primary spraying disk in which a large number of primary spraying holes are formed in a peripheral wall axially concentric with the inner cavity of the secondary spraying disk, and the primary spraying disk is rotated. The inner tube for liquid raw material supply which is movably installed and which feeds the stock solution to be dried is inserted through the axis of the rotary tube shaft on which the disk for secondary spraying is installed, and the primary spraying bewitching board is installed. The centrifugal sprayer for a spray dryer according to claim 1, wherein the centrifugal sprayer is configured to be rotationally driven by an external rotary driving device via the inner pipe for supplying the liquid raw material.