JP3163165B2 - Spray drying equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to a spray drying apparatus suitable for producing all powdered and particulate products produced or processed by spray drying.

[0002]

2. Description of the Related Art Conventional spray drying apparatuses are disclosed, for example, in JP-B-63-21107 and JP-B-2-39549.
Japanese Unexamined Patent Publication (Kokai) No. H10-264, pp. 157-334 is known. That is, in the former, a porous cylindrical member is fixedly provided concentrically with the sprayer at the hot air discharge port of the spiral duct, and a lower cylindrical member having the same diameter that is continuous with the lower end of the porous cylindrical member is set at the height of the sprayer. A plurality of straightening plates extending from a substantially middle height of the perforated cylindrical member to a lower end of the lower cylindrical member are radially projected from the inner surface thereof. The latter is a honeycomb in which a number of regular hexagonal small holes are formed between a straightening plate disposed between a chamber in which a spray nozzle opens and a hot air passage member to straighten hot air supplied to the chamber. It is a structure.

[0003]

In the above-mentioned conventional spray drying apparatus, the former uses a rectifying plate to regulate the discharge direction of hot air and forms a vortex to intersect with droplets for heat exchange. The flow rate, direction, temperature distribution, etc. of the hot air flowing out are regulated, and as a result, only physical properties with a specific particle size distribution can be obtained.
Accordingly, another spray drying apparatus having different design conditions capable of generating different hot air is required, and there is a problem that it is not versatile.

In the latter, the hot air to be fed is simply rectified and passed through a regular hexagonal honeycomb structure having a large passing area.
Direction and temperature conditions are regulated, and only physical properties of a specific particle size distribution can be obtained, which has a problem of lack of versatility.

The present invention provides a hot air control function with a high degree of freedom, which is not provided in a conventional spray drying apparatus, so that a single spray drying apparatus can obtain powder particles of various physical properties. It is an object of the present invention to provide a spray-drying device having a high drying efficiency.

[0006]

In order to achieve the above object, the present invention provides a spray nozzle for spraying a liquid disposed in an upper part of a drying tower, and a spray nozzle which is sprayed from an outlet on a top surface in the drying tower. In a vertically descending co-current spray drying apparatus for discharging hot air in parallel with a liquid, a hot air chamber for temporarily storing hot air is provided above the top surface, and a corrugated spiral straight chamber is provided in the outlet.
A rectifier for hot air comprising a honeycomb ;
, And a plurality of perforated plates having various shapes are provided so as to be exchangeable with a small space therebetween .

[0007]

The hot air is housed in a hot air chamber once, eliminates the uneven flow generated by the hot air duct in the hot air chamber, makes a uniform pressure state, and has a shape corresponding to the spread and distribution density of the spray particles sprayed from the nozzle. By selecting the perforated plate at the outlet, the hot air is rectified by the rectifier while being controlled to the desired hot air outlet and hot air velocity distribution, and thus the spray particles are subjected to high initial drying and turned into powder particles. At the same time, it does not fly out of the main stream of hot air and adhere to the inner wall of the drying tower in an undried state, and does not stick.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS.

Reference numeral 1 denotes a drying tower. An outlet 1a is formed on the top surface of the drying tower 1, and the outlet 1a is provided above the top surface.
a is provided with a closed cylindrical hot air chamber 2 communicating with the hot air chamber 2.
An opening 2a is formed in the center of the lid.

Reference numeral 3 denotes a supporting member. The supporting member 3 is fixed to an inner edge of the opening 2a at an upper end thereof through an auxiliary lid 3a which is detachably engaged with an outer edge of the opening 2a and a center through hole of the auxiliary lid 3a. A support pipe 3b fixed to the lower end of the support pipe 3b via an arm 3c and supporting a rectifier 7 described later; a supply pipe 6 having a spray nozzle 5 at a lower end in the support pipe 3b; Insert and lock.

Reference numeral 7 denotes a rectifier. The rectifier 7 is formed as a straight honeycomb in which a corrugated plate 7b is welded between strip-shaped spirals 7a as shown in FIGS. 2 and 3, and an arm is provided in the holding cylinder 3d. 3c.

Reference numeral 8 denotes a perforated plate. The perforated plate 8 is formed by dividing a doughnut-shaped or disc-shaped flat plate with a large number of holes 8a... 8a as shown in FIG. Various shapes and aperture ratios are available.
In addition, 9 is a hot air duct communicating with the opening of the side wall of the hot air chamber 2, 10 is an outlet at the bottom of the drying tower 1, and 14 is to close a through hole for inserting the auxiliary hot air duct 13 as described later. 2 shows a side wall cover.

Next, the operation of the above embodiment will be described.

For example, when the spray particles of the material to be dried sprayed from the spray nozzle 5 are in a state as shown in FIG. 5A from the characteristics of the material to be dried or the characteristics required for the product, the spraying is first performed from the support pipe 3b. When the supply pipe 6 is taken out together with the nozzle 5 and the auxiliary lid 3a is removed from the opening 2a, the holding pipe 3d is taken out together with the support pipe 3b from the hot air chamber 2 to the outside, and the arm 3c is placed inside the holding pipe 3d. Then, a straight honeycomb is set in a spiral shape to form a rectifier 7, and then a hot air outlet and a perforated plate 8 which can be controlled to a hot air velocity distribution as shown in FIG. The plate 8 is mounted above the rectifier 7 in the holding cylinder 3d with a small gap.

[0015] Thereafter the holding cylinder 3d in a hot air chamber 2 placed in the holding tube 3d support pipe 3b for locking the auxiliary cap body 3a on the periphery of the opening 2 a is located in the outlet 1a, then the feed pipe 6 When the spray nozzle 5 faces the upper part of the drying tower 1 by inserting and locking the inside of the support pipe 3b and hot air flows into the hot air chamber 2 from the hot air duct 9, the hot air is temporarily stored in the hot air chamber 2. And the hot air is blown into the perforated plate 8
At the central opening, and flows straight down by the rectifier 7 into the drying tower 1.

On the other hand, in the peripheral portion of the perforated plate 8, a small amount of hot air flows into the gap between the perforated plate 8 and the rectifier 7 through the pores of the perforated plate 8, and the inside of the gap does not become a negative pressure but a little. It becomes positive pressure. Thus, even in the periphery of the opening of the perforated plate 8, the hot air flows straight and flows down without flowing into the gap, and thus the velocity distribution of the hot air matches the distribution state of the spray particles as shown in FIG. 5B. Are formed, and the spray particles are dried and granulated.

Next, from the characteristics of the material to be dried or the characteristics required for the product, for example, when the spray particles of the material to be dried sprayed from the spray nozzle 5 are in a state as shown in FIG. When the perforated plate 8 is mounted so as to be located at the center and the peripheral portion of the outlet 1a by the above operation, the velocity distribution state of the hot air into the drying tower 1 becomes as shown in D, and thus the state C of the spray particles and the hot air The velocity distribution state D is the same, and the spray particles are sufficiently and reliably dried and granulated by the hot air.

Next, for example, when the spray particles of the material to be dried sprayed from the spray nozzle 5 are in a two-stage state as shown in FIG. Are two perforated plates 8 having different central opening areas,
8 is attached to the periphery of the outlet 1a with a gap t interposed between two stages, the velocity distribution of the hot air into the drying tower 1 is as shown by F, and thus the state E of the spray particles and the hot air And the spray particles are sufficiently and surely dried and granulated by the hot air.

FIGS. 8 and 9 show another embodiment of the rectifier 7, in which the honeycomb surface 7c of the rectifier 7 is formed with an inclination angle α. Therefore, the hot air that has flowed into the drying tower 1 at the inclination angle α forms a swirling flow.

FIG. 10 shows a second embodiment of the present invention. In this embodiment, a shunt tube 12 and a partition top plate 15 connected to the outside of the upper end of the shunt tube 12 are installed on the rectifier 7 to perform the shunt. An auxiliary hot air chamber 11 is provided outside the cylinder 12.
An auxiliary hot air duct 13 is connected to the outlet of the hot air duct 9, and when the central part of the spray particles of the material to be dried sprayed by the spray nozzle 5 is harder to dry than the peripheral part, the temperature of the hot air supplied from the hot air duct 9 is adjusted. By making the temperature of the auxiliary hot air supplied from the auxiliary hot air duct 13 higher and flowing the hot air and the auxiliary hot air from inside and outside of the flow dividing tube 12 , the spray particles can be sufficiently and reliably at the center as well as at the periphery. Dry and atomized.

Here, the flow dividing cylinder 12 and the partition top plate 15
Is formed, for example, bilaterally symmetrically and can be additionally installed when the rectifier 7 described in the first embodiment is mounted.

As described above, in the spray drying apparatus of the present invention, the perforated plates 8 having various shapes or different opening ratios can be arbitrarily provided, various perforated plates 8 can be combined with the rectifier 7, or from inside or outside of the flow dividing cylinder 12. By the flow of the hot air and the auxiliary hot air, desired powders can be obtained from various materials to be dried.

[0023]

As described above, according to the present invention, the hot air chamber for temporarily storing the hot air is provided above the top surface of the drying tower, so that the hot air is once stored in the hot air chamber and is then passed through the hot air duct by the hot air duct. The generated uneven flow is eliminated and the pressure becomes uniform, and a rectifier for rectifying the hot air is provided at the outlet of the hot air chamber, and a perforated plate for controlling the velocity distribution of the hot air is exchangeably provided near the rectifier. Therefore, it has a velocity distribution according to the distribution state of the spray particles, makes it possible to reliably and sufficiently supply rectified hot air, and furthermore, the main flow in the drying tower formed by the perforated plate and the secondary flow outside the drying tower The flow can prevent powder particles from sticking and burning, and as a result,
It can reliably dry materials that have various characteristics, such as materials that are difficult to dry, materials that have high adhesion to the inner wall, and materials that are easily thermally denatured. Has the effect of increasing significantly.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of the present invention.

FIG. 2 is a plan view of an example of the rectifier of the present invention.

FIG. 3 is a sectional view taken along the line III-III of FIG. 2;

FIG. 4 is a plan view of the baffle plate of the present invention.

FIG. 5

FIG. 6

FIG. 7 is an explanatory diagram showing each example of a state of a spray liquid and hot air.

FIG. 8 is a plan view of another example of a rectifier.

9 is a sectional view taken along the line IX-IX of FIG.

FIG. 10 is a sectional view showing a main part of a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Drying tower 2 Hot air chamber 5 Nozzle 7 Rectifier 8 Perforated plate 12 Separating cylinder

──────────────────────────────────────────────────続 き Continuation of the front page (56) References Japanese Utility Model Sho 63-69537 (JP, U) Japanese Utility Model Hei 3-22522 (JP, U) Japanese Utility Model Sho 53-37964 (JP, U) Japanese Utility Model Sho 59- 48701 (JP, U) Jiko 2-39549 (JP, Y2) (58) Field surveyed (Int. Cl. ⁷ , DB name) B01D 1/16-1/20

Claims (4)

(57) [Claims] 1. A spray nozzle for spraying a liquid disposed at an upper part in a drying tower, and a vertical descending co-current type for discharging hot air in parallel with the liquid sprayed from an outlet at a top surface in the drying tower. In the spray drying device, a hot air chamber for temporarily storing hot air is provided above the top surface, and a corrugated spiral storage is provided in the outlet.
A hot air rectifier made of honeycomb is provided and
Different porosity of various shapes with a small space above the flower
A spray-drying device characterized in that the plates are exchangeable. 2. The honeycomb of the corrugated spiral straight honeycomb.
2. The honeycomb structure according to claim 1, wherein the honeycomb surface is formed as an inclined surface.
A spray drying apparatus according to claim 1. 3. The perforated plate is a circle each having a different outer diameter.
Donut plate with board shape or different inner or outer diameters
The spray dryer according to claim 1, wherein the spray dryer is formed in a shape . 4. A diverter is provided on the rectifier, wherein the diverter is
2. The spray drying apparatus according to claim 1, wherein hot air having different temperatures is supplied to the inside and outside of the apparatus.