US1878588A - Spray head - Google Patents

Description

Sept. 20, 1932. J. c. MacLAcl-ILAN 1,878,538

SPRAY HEAD, A

Filed June 1a. 1931 2 sheets-'sheet 1 1/ KD .,..u..,.. kill i F SPRAY HEAD Filed June 18, 1931 2 Sheets-Sheet 2 Patented Sept. 20, 1932 UNITED STATES PATENT OFFICE l JOHN C. MACLACHLAN, OF CHICAGO, ILLINOIS, .ASSIGNOR TO 'DEE-HY PRODUCTS COM- PANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS SPRAY HEAD Application led June 18, 1931. Serial No. 545,223.

This invention relates to a drying apparavhead taken along the line II-II of Fig. 3,

tu's for drying liquids or semi-liquid material and partcularly to a distributing head for such an apparatus.

As is well known, such drying apparatus is now used for drying milk, buttermilk, blood, fruit juices, and various other liquids. In the present type of apparatus the liquid is dried by being discharged into a drying chamber in a very iine condition and dried by heated air passing through said chamber. In drying whole milk and other colloidal liquids, it is desirable that the liquid be dividedY as tinely as possible without impact as the impact tends to coagulate the at and other globules in the milk and to prevent the dried product from going readily into solution.

In the previously used types of apparatus, the milk, or other liquid is distributed centrifugally by a discharging head which is drven atvery high speed. If a single disc is used, it is necessary to have quite a large diameter to secure the necessary peripheral speed for throwing the material outwardly to divide the same, and it is necessary to drive the disc at extremely high speed.

Previously, I have invented a distributing or spray head which, in a measure, overcomes this diiiiculty. It is disclosed in my U. S. Patent No. 1,742,478. This was a decided improvement over methods then in use but-there was still a chance for the impact of a small percentage of the particles, this impact being between the particles and portions of the succeeding blade in the spray head.

It is an object of this invention, therefore, to provide a spray head which will distribute the liquid with substantially no impact between any of the spray particles and any surface of its revolving members.

This and other objects and advantages of the invention will be fully set forth in the following description made in connection with the accompanying drawings, in which similar reference characters refer to similar parts throughout the several views, and in which;

Figure 1 is a vertical sectional view through the drying cabinet of the drying apparatus;

Figure 2' is a sectional view of the drying with parts in elevation; Figure 3 is a sectional view taken along the line III-III of Figure 2, with parts in elevation.

Referring to the drawings, a drying apparatus is shown comprising a cabinet 1 hav ing walls 2, said cabinet being of polygonal shape in cross-section or of cylindrical shape. The cabinet is shown as having receiving hoppers or compartments 3 at its bottom with converging bottom walls having discharge outlets 4. The cabinet 1 has a top 5 through which projects a distributing apparatus 6. The liquid to be vaporized is fed through a pipe 7 to a rotating head forming a part of said distributing apparatus 6. -An inclined wall 9 extends about the upper corner of the cabinet forming a chamber 10 through which some of the entering-air passes. Said wall has openings 11 therethrough communicating with chamber 10. A. rod 12 is shown extending around the wall 2 adjacent to its upper end, lfrom which issuspended a fabric or flexible curtain 13. The drying air is supplied at the bottom of the cabinet and substantially at the center thereof by a conduit 14, above which is a conical deflector 15 surrounded by a cylinder 16. Said cylinder 16 is open at its upper end` but has a bar 17 across its top forming one of the bearings for the deflector 15. The cabinet 1 or the wall 2 thereof has a plurality of discharge open- 22, a distributing member 23, and a ring 24 which supports the fan blades 25. The bell shaped member 22'is internally threaded at its upper end to engage the lower end of the tube 21. Its middle portion is enlarged to form the chamber 26 and its lower portion is fiared to form the bell shaped portion 42 and the two series of blades 28 and 29. The ring 24 is adjustably mounted on the member 22 by means of the set-screws 30. The blades 25 are adjustably held in said ring 24 by means of set-screws 31. A recess or groove 32 is rovided in each of said fan blades 25 direct y under. set-screws 31 to prevent the blades from coming out of the ring 24 if the set-screws should become loose during operation.

The two series of blades 28 and 29, the exact construction of which forms an important feature of my invention, are staggered with respect to each other, the series 28 being bent out more than series 29. Each of these blades is substantially flat on its lower side but the top surface isrounded off so that the outer edge.33 is relativel sharp. Said series of blades 28 and 29 are evelled along each radial edge, forming surfaces as at`34 and 35. These blades are so formed that their inner or outer'surfaces will generate surfaces rather than solids when the head is rotated about its axis, as when it is in operation. In this respect, my present invention diilers radically from that disclosed in my U. S. Patent No. 1,742,478, the blades in that invention being tilted so as to produce a strong current of air. Slits 36 occurring between the two series of blades 28 and 29 serve the purposeof allowing suitable proportions of the current of air from the fan blades 25 to pass by the edges of the blades thereby atomizing or dispersing the liquid, producing very fine droplets.

The portion of the bell shaped member 22, occurring just under the chamber 26 is internally threaded to support the distributing member 23. Said distributing member 23, shown partly in cross-section and partly in relief, (Fig. 3) comprises a ring portion 37, which is threaded externally to engage with said bell shaped member 22. A cone shaped portion 38 is formed on a disk shaped portion 39 of said distributing member 23. Said ring portion 37 is formed integrally with the cone shaped portion 38, to which it is attached by means of a series of spaced lugs 40 between which occur the openings 41.

In operation, the head will be disposed in the drying chamber as shown in Fig. 1 and said head will be rotated at high speed, say about 3,000 to 5,000 revolutions per minute.

The liquid to be sprayed is fed into the pipe7. On leaving the lower end of said pipe it comes into contact with the cone 38 and escapes through the openings 41 between thevdisk 39 and the ring portion 37. The high speed of rotation causes this liquid to be thrown outwardly and downwardly, coming into contact with the under surface of the portion 42 of the member 22 at such a small angle that the im act is not in any way injurious to the llquid. The liquid travels down ,the inner surface of the blades 28 and 29 of the member 22 and finally is thrown off their ends and edges.

The novel staggered position of the blades, fully explained above, allows all articles to get free from the edge of one bla e before the next blade comes into a position for contact with the particles, so that there is n0 such destruction of the colloid particles as would render the dried materialmuch less soluble than it otherwise would be. At the same time the air current created by the fan blades 25 is passing. downwardly through the openings 36 between the blades 28 and 29 of the member 22 and over the outer edges of the blades 28 and 29.I 4

Adjustment may be made of the air current created by the fan blades 26 by loosening the set-screws 31 and rotatingeach blade until the desired pitch is produced and ti ht- `ening said screw. Adjustment of the helght of the fan bladesl 26 above the blades 28 and 29 may be made in a similar manner by means of the set-screws 30. Also, it is under some conditions desirable to place a cylinder 27 (Fig. 1) over or around the device so as to direct the air current against the blades 28 and 29 with greater force. This current of air divides the liquid into very minute particles which will dry quickly yby virtue of their small size.

The general operation of a dehydrating cell like that shown in Figure 1 will be readily understood by anyone skilled in the art, and since it does not form a part of the resent invention, it will not be described ere. I have set forth the general principles of this method of spray drying more fully in my United States Letters Patent No. 1,742,478.

From the foregoing description, it will be seen that I have made a distinct improvement in the apparatus forI spray. drying liquid by providing a devicewhereby liquid may be vaporized without impact of the globules, with its consequent detrimental ef-` fect on the subsequent solubility of the dried product.

I am aware that many changes may be made and numerous details of construction may be varied through a wide range without departing from the principles of this invention, and I, therefore, do not purpose limiting the patent granted hereon otherwise than necessitated by the prior art.

I claim as my invention:

l. A distributing head for a liquid dehydration cell, comprising a rotatable member having blades alternately lying in substantially conical surfaces and means for feeding films of liquid along the inner faces of said blades to be thrown therefrom by'centrifugal I force and atomized by currents of air passing dration cell, comprising a rotatable member having closely spaced blades, alternate blades lying in slightly divergent conical surfaces, and means for feeding films of a liquid onto the inner surfaces of said blades for distribution therefromwithout substantial impact against said blades.

3. A distributing head for a liquid dehydration cell,.comprising a rotatable member having closel spaced blades, alternate blades lying in slig tly divergent conical surfaces, means for feeding films of a liquid onto the inner surfaces of said blades for distribution therefrom without substantial impact against said blades and means for directing a current of air against the outside surfaces of said blades and between said blades to effect atomization of said liquid films.

4. In a distributing head for a liquid dehydration cell, a rotatable"member having closely spaced blades presenting surfaces lying almost completely within substantially conical surfaces, means for feeding a liquid to said blade surfaces, other blades revoluble with said member and a sleeve surrounding said other blades to direct currents of air against the outer surfaces of said first mentioned blades.

5. In a distributing head for a liquid dehydration cell, a rotatable member having closely spaced blades presenting surfaces lying almost completely within substantially conical surfaces, means for feeding a liquid to said blade surfaces, including a feed pipe and a conical distributer spaced from the open end of said pipe and adjacent said blade surfaces and other blades revoluble with said member to direct currents of air against the outer surfaces of said first mentioned blades.

6. In a distributing head for a liquid dehydration cell, a rotatable member having closely spaced blades presenting surfaces lyingalmost completely within substantially conical surfaces, means for feeding a liquid to said blade surfaces, including a feed pipe and a conical distributer spaced from the open end of said pipe and adjacent said blade surfaces, other blades revoluble with said member and a sleeve surrounding said other blades to direct currents of air against the louter surfaces of said first mentioned blades.

7. In a liquid dehydration cell, a distributing head positioned in the top wall thereof kand dependent therefrom comprising a rotatable tube, an inner liquid feed pipe terminating within said tube, a member secured to said tube and having closely spaced outwardly and downwardly sloping blades, fan

blades secured to said member above said other blades, an open-ended sleeve secured to and surrounding said fan blades and means spaced from the open end of said feed pipe for distributing liquid over the inner surfaces of said first mentioned blades.

8. In a liquid dehydration cell, a distributing head positioned in the top wall thereof and dependent therefrom comprising a rotatable tube, a member secured to said tube and having closely spaced outwardly. and downwardly sloping blades, fan blades secured to said member, above said other blades, and being adjustable as to pitch and also adjustable as a unit on said tube relative to said first mentioned blades, an inner liquid feed pipe terminating within said member, and means spaced from the open end of said feed pipe for distributing liquid over the inner surfaces of said first mentioned blades.

9. In a liquid dehydration cell, a distributing head positioned in the top wall thereof and dependent therefrom comprising a rotatable tube, a member secured tosaid tube and having closely spaced outwardly and downwardly sloping blades, alternate blades. lying in slightly divergent conical surfaces, fan blades secured to said member above said other blades, an open-ended sleeve surrounding said fan-blades, an inner liquid feed pipe terminating within said member and means spaced from the open end of said feed pipe for distributing liquid over the inner surfaces of said first mentioned blades.

10. The method of drying milk which comprises distributing .the same centrifugally on a surface to. form a thin film, distributing said film without impact onto a plurality of discontinuous surfaces lying in slightly divergent coaxial cones, revolving said surfaces at high speed and causino air to pass downwardly between said surfaces to separate said milk into nely divided condition as it is thrown from said surfaces centrifugally.

11. The method of drying milk which com-` prises distributing said milk centrifugally in a thin film or layer, transferring said film without impact to a system of discontinuous surfaces lying in slightly divergent coaxial cones, causing air to pass in a downwardlyl directed stream at high velocity over and between said vsurfaces to separate said milk into finely divided condition as it is thrown from said surfaces.

12. The method of drying colloidal liquids which comprises distributing the same onto the under side of a system of discontinuous surfaces, staggered with respect to each other and arranged about a central axis and revolving at high speed about said axis, causing the liquid to be distributed centrifugally from said surfaces, and causing a current of air to pass downwardly over and between said surfaces thereby breaking the liquid into numerous small droplets.

13. A distributing head comprising a rotatable flared member having divided slopmg surfaces which unite to form a single 1anA conical surface toward their upper ends and divide into two alternating sets staggered with respect'to each other at their lower ends and means for feeding a iilm of liquid to the inside surface of said member for distribution over said surfaces substantially ,without impact. l

In testimony whereof I have hereunto sub-- scribed my name at Chicago, Cook County,

Illinois.

JOHN Cm MAOLACHLAN.

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