JPH0612803Y2 - Centrifugal sprayer sprayer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a spraying disc of a centrifugal spraying device used in a spray dryer or the like.

[Prior Art] Conventionally, as shown in FIG. 3 of Japanese Utility Model Publication No. 61-10767, as this type of sprayer, an upper mounting disk 15 and a lower mounting disk 1 are used.
It has been proposed that the spraying cone roller 17 is mounted between 6 and approximately concentrically along the periphery thereof.

A Kessner type sprayer having a structure as shown in FIG. 4 is also known.

[Problems to be solved by the device]

However, these conventional techniques are not available in Japanese
In the spray disc 3 of -10767, as shown in FIG. 3, the distance between the upper mounting disc 15 and the lower mounting disc 16 is narrow, and the central raised portion 18 is located at the center portion. The space between the lower mounting disk 16 and the spray disk 3 is small.
During cleaning, there was a problem that the inside was narrow and the inside was not visible, making cleaning difficult.

Further, in the Kessner type spraying disc 3 as shown in FIG. 4, there is a problem that atomization is difficult during spraying.

[Means for Solving the Problems]

Therefore, as a result of various studies in view of the above-mentioned conventional problems, the inventor of the present invention has increased the distance between the upper mounting disc and the lower mounting disc of the sprayer, and has the upper mounting disc of the reverse funnel shape. The present invention has been found out that the conventional problem can be solved by forming the lower mounting disk into a so-called annular shape with the central portion thereof removed, in addition to the above.

That is, according to the present invention, a reverse funnel-shaped main mounting disk having a stock solution inlet at the top, a hollow lower mounting disk located below the main mounting disk, and a space between the two disks. A spraying disc for a centrifugal spraying device, comprising: a plurality of spraying pins provided on the circumference of a disc.

Further, in the present invention, it is preferable to provide a projection on the lower portion of the inner edge portion of the main mounting disc, because atomization of the spray is further promoted.

Furthermore, it is preferable to form the spray pin so as to have an inverted conical shape, because the liquid droplets are not sprayed upward, so that the liquid droplets do not adhere to the ceiling portion of the spray drying chamber.

[Action]

The undiluted solution introduced from the undiluted solution supply port of the spraying disk flows down as a liquid film along the inner circumference of the inverted funnel-shaped main mounting disk by the rotation of the spraying disk, and the main mounting disk and the lower mounting disk. Reach a plurality of spraying pins provided on the circumference of the. Next, the falling liquid film is atomized outward and sprayed through the spraying pin by the centrifugal force generated by the rotation of the spraying disc.

〔Example〕

Hereinafter, the present invention will be described in more detail based on the illustrated embodiments, but the present invention is not limited to these embodiments.

FIG. 2 is a schematic view of an embodiment of the centrifugal spray dryer. The stock solution supplied from the stock solution supply pipe 1 is sprayed as fine particles from the spraying plate 3 of the present invention into the spray drying chamber 4 via the liquid distributor 2 and fed into the spray drying chamber 4 from the hot air inlet 5. It is dried by the hot air, becomes a granular material, falls, and is taken out from the product take-out port 6. On the other hand, the exhaust gas passes through the exhaust pipe 7, the powder particles are separated and collected by the cyclone 8, and then discharged.

Here, as a basic idea regarding uniform atomization of droplets in the above spray drying, the following has been conventionally known. That is, it is said that more uniform fine particles are achieved by a more uniform liquid film thickness and a uniform atomizing force, and the average particle diameter of the fine particles is changed by the liquid film thickness and the atomizing force.

This atomization force is the pressure of the liquid in the case of a pressure nozzle, the pressure and amount of the gas in the case of a two-fluid nozzle, and in the case of the centrifugal atomizer such as the present invention, the collision between the liquid and the gas blown by the centrifugal force. Power.

FIG. 1 (a) is a schematic sectional view of the spraying disc 3 of the present invention.
The spraying pin 10 is fixed between the main mounting disc 13 and the lower mounting disc 9 by bolts 11. Here, the main mounting disk 13 has an inverted funnel shape and has a predetermined distance (height) 1 in the vertical direction. The vertical distance l of the main mounting disc 13 is specifically 0.3 to the diameter of the main mounting disc 13.
About 1.0 times is appropriate.

Further, the lower mounting disk 9 has a hollow shape with an opening in the center thereof, and the opening 20 has a main mounting disk 13 from the bottom.
It is preferable that the inclined portion has a size such that it can be visually observed, and specifically, it has a diameter that is about 60 to 90% of the outer diameter of the lower mounting disk 9. The shape of the opening 20 is preferably circular, but may be elliptical, rectangular, or the like.

The undiluted solution that has entered the inside of the spraying disc from the supply liquid port 12 of the main mounting disc 13 mounted on the rotating shaft 19 flows down in the form of a thin film along the inner peripheral portion of the main mounting disc 13 and sprays the spray pin 10 The centrifugal pin generated by the rotation of the spraying disk 3 causes the spraying pin 1
It is sprayed into the spray drying chamber 4 from 0.

Further, in the present invention, the shape of the spraying pin 10 is not particularly limited, and may be, for example, a conical shape, an inverted conical shape, or an hourglass shape having a dented central portion. The conical shape is preferable because droplets are not sprayed upward.

FIG. 1 (b) shows another embodiment in which a protrusion 14 is provided in the circumferential direction below the inner edge of the main mounting disc 13. Providing the protrusions 14 improves the spray performance of the stock solution, which is preferable.

Hereinafter, a concrete implementation result of the present invention will be described.

(Example) Specific gravity 1.1 containing 22.5 wt% of alumina as a stock solution
7. A spraying experiment was carried out using a slurry having a viscosity of 30 centipoise. As compared with the conventional Kessner type spraying disk shown in FIG. 4, in the case of the same rotation speed and diameter, the graph shown in FIG. Thus, there is a significant improvement in the size distribution of atomized droplets. The outer diameter of the sprayer used was 84 mm, and the distance from the upper end to the lower end of the main mounting disc was 38 mm.

Further, in the case of the spraying disc according to the present invention, the sprayed droplets did not adhere to the ceiling portion, but in the conventional spraying disc shown in FIG. 3, the droplets adhered to the ceiling portion.

Furthermore, in the conventional spraying machine of FIG. 3, it was difficult to clean and clean the inside, but the spraying machine of the present invention widens the space inside the spraying machine and opens the lower part, so that the cleaning is performed.・
It was easy to clean.

[Effect of device]

As described above, the spraying disc of the present invention has the following effects.

In the spray disc according to claim 1, since the distance between the main mounting disc and the lower mounting disc is large, the space surrounded by both discs is wide, and the central portion of the lower mounting disc is open. Therefore, the inside of the sprayer can be easily washed and cleaned.

In the spraying disc of the second aspect, since the projection is provided on the lower portion of the inner edge portion of the main mounting disc, atomization of the spraying can be further achieved.

In the spraying disc of the third aspect, since the spraying pin has an inverted conical shape, the droplets are not sprayed upward, so that they do not adhere to the ceiling portion of the spraying chamber, which is preferable.

[Brief description of drawings]

1 (a) and 1 (b) are cross-sectional schematic views showing examples of the spraying disc of the present invention, and FIG. 2 is a schematic view of a spray drying apparatus using the spraying disc of the present invention, FIGS. Is a schematic sectional view of a conventional spraying disk, and FIG. 5 is a graph showing a particle size distribution of sprayed droplets. 3 ... Spraying disc, 9 ... Bottom mounting disc, 10 ... Spraying pin, 12
... Supply liquid port, 13 ... Main mounting disc, 14 ... Protrusion, 19 ...
Rotating shaft, 20 ... Opening.

Claims (3)

[Scope of utility model registration request] 1. A reverse-funnel-shaped main mounting disk having an undiluted solution supply port at an upper portion thereof, a hollow lower mounting disk located below the main mounting disk, and between the both disks. A spraying disc for a centrifugal spraying device, comprising: a plurality of spraying pins provided on a circumferential portion of a disk. 2. A spraying disc for a centrifugal spraying device according to claim 1, wherein a projection is provided on a lower portion of an inner edge portion of the main mounting disc. 3. The spray pin has an inverted conical shape.
A spray plate of the centrifugal spray device described.