US2307311A - Refrigerating machine - Google Patents

Description

Jan. 5, 1943. E. F. vlLTER vlr AL 2,307,311

REFRIGERATING MACHINE v Filed oct. 13, l1941 Patented Jan. 5, 1943 v 2,307,311 REFRIGERATING MACHINE Ernest F. Vilter and Stephen A. Husty, Milwaukee, Wis., assignors to The Vilter ing Company, Milwauk of Wisconsin Manufacturee, Wis., a corporation Application october r3, 1941, semi No. 414,*'192 2 claims. (c1. ca -106) The present invention relates generally to improvements in the art of refrigeration, and relates more specifically to improvements in the construction and operation of machines for producing ice and especially so-called crystal-form ice. An object of the invention is to provide various improvements in the details of construction of refrigerating machines, whereby the cost of manufacture of such machines is reduced to a minimum while the eiliciency thereof is enhanced to a maximum.

Continuous crystal-form ice making machines such as shown in Taylor U. S. Patent No. 2,080,639, granted May 18, 1937, have heretofore been manufactured and used commercially with considerable success for producing slush or snow ice for various purposes where crushed ice is required. This type of machine comprises an annular casing formed of a single helically wound tube tue adjoining coils of which provide a continuous circular freezing surface, and an ice-removing rotor revolvable within the casing about the central axis thereof and having blades co-operable with the freezing surface to constantly remove the ice therefrom. .The tubing used in the construction of the casings of these prior machines, was preferably formed of aluminum, and since this metal has become rather precious and dicult to obtain, the manufacturers of such ice machines are obligated to seek substitute materials. It was then proposed to utilize sheet metal casings of iron or steel, each casing being formed of concentric cylindrical inner and outer sheet metal walls of different diameters having a helical vane or rib therebetween forming a helical passage for the refrigerant; but it was found that when these substitute casings were made in normal fashion with the helical rib contacting both walls, considerable loss`in efficiency occurred as compared to the former aluminum tubular casings. We

have discovered, however, that by allowing slight clearance or spaces between one of the edges of the helical vane or rib and the adjacent wall, the eiciency of these casings is restored and even augmented, and the cost of producing the new casings is far less than that of the prior tubular wound aluminum casings.

It is therefore a more specific object of our present invention to provide an improved cooling or ice forming casing for continuous refrigerating or ice producing machines, which is simple and durable in construction, and whichis moreover highly efcient in operation.

Another specific object of the present invention is to provide a new and useful circular casing for rotary refrigerating machines, which can be easily constructed at moderate cost and from materials which are ordinarily readily available.

A further specific object of this invention is to provide an improved refrigerator casing of the type having one or more circular or helical ducts for conducting refrigerant along the cooling surface thereof, and which is formed to most effectively conduct and distribute the refrigerant in proximity to the cooling surface.

Still another specific object of our invention is to provide an improved continuously functioning crystal-form ice making assemblage, which is simple and compact in construction and extremely effective in use.

These and other objects and advantages of the present invention will be apparent from the following detailed description.

A clear conception of the features constituting our present improvements, and of the mode of constructing and of utilizing ice machine casings .built in accordance with the invention, may be had by referring to the drawing accompanying` and forming a part of this specification wherein like reference characters designate the same or similar parts in the various views.

Fig. 1 is a central vertical section through a continuous crystal-form ice making machine embodying one of the improved casings;

Fig. 2 is an enlarged fragmentary outside view and partial section of one of the improved ice machine casings; and

Fig. 3 is a similarly enlarged part sectional and fragmentary top view of the casing of Fig. 2.

While the invention has been shown and described herein as being especially applicable to a continuous vertically disposed rotary crystal-form ice making machine, it is not our desire or intent to thereby unnecessarily restrict the scope or utility of the improvement.

With specific reference to the drawing, the continuous vertical ice making machine shown therein, comprises in general a main cylindricalcasing 5 having an inner annular wall 6 provided with a continuous cylindrical cooling surface 1, an outer annular wall 8 disposed concentrically of and surrounding the .inner wall 6, and one or more circular or helical ribs 9 disposed within the annular space between the walls 6, 8 and forming one or more'refrigerant confining and distribution ducts I0 surrounding the casing axis and extending from the bottom to the top of the-casing 5; a rotor Il mounted upon an upright shaft l2 disposed cen- `trally within the casing' 5, and having a series of radial arms I3 carrying knives or scraper blades Il adapted to co-operate with the cylindrical cooling surface 1 of the annular inner wall 8,; and a motor I5 drivingly connected by means of gearing I8 and a coupling I1, to the upper end oi' the rotor shaft I2.

The annular main casing 5 which constitutes an important part of the present improvement. is preferably formed of relatively inexpensive sheet metal plates, such as iron or iron alloy, and the annular walls 6. 8 may be rigidly interconnected at their lowerl and upper extremities respectively, by means of annular horizontal closure plates I8, I9 which may be welded in position as shown. The circular or helical ribs 9 which form the duct I0, may have one edge rigidly attached as .by welding, to one of the casingwalls but not both. and the unattached edge of these ribs 9 should be spaced slightly from the adjacent wall so as to provide a rather restricted passage 20 between the successive adjacent coils of the duct I0. The upper portion of the outer casing wall 8 may be provided with a suspension ange 2 I and the exterior of this wall 8 is preferably snugly embraced by an annular layer of insulation 22; and the casing 5 may also be of any desired height depending upon the capacity and size of the particular machine. The outer wall 8 of the main casing 5 may also be provided with a lower liquid refrigerant inlet 23 and with an upper gaseous refrigerant outlet 24, the former of which communicates with the lower extremity of the duct I while the latter likewise communicates with the upper end of this duct.

The rotor shaft I2 may be journalled in bear- v ings 25, 26 carried by lower and upper spiders 21, 28 respectively, and the casing flange 2| may be secured directly to the upper spider 28 by means of cap screws 29, while the lower spider 21 may be omitted in small machines. The rotor assemblage and driving mechanism may be similar to the corresponding structures shown in the Taylor Patent No. 2,080,639, and the fresh liquid or other material supply may be introduced to the cooling surface I in any desired manner while the congealed liquid or snow ice is free to drop by gravity through the lower open end of the fixed casing 5. During normal operation of the improved ice making unit, the rotor II is being continuously rotated at an appropriate speed by means of the driving motor I5, and fresh liquid such as water may be constantly delivered against the cylindrical cooling surface 1. The liquid refrigerant admitted into the lower portion of the casing through the inlet 23 will be constantly converted into gas which rises through the circular passage or duct I0 formed by the rib 9 coacting with the casing walls 6,' 8, and eventually escapes through the upper outlet 24. The refrigerant while passing upwardly through the casing 5, maintains the freezing surface 1 of the inner wall 6 at relatively low temperature at all times, and thus transforms the fresh liquid delivered against the surface 1 into a lm of ice. As the scraper blades I4 are advanced along the cylindrical surface 1 due to revolution of the carrying rotor Il, these blades constantly scrape the ice film from the surface 1 anddeposit the same in crystalform by gravity through the lower opening of the casing 5. In this manner, the crystal-form or snow ice Vis produced continuously whenever the machine is operating, and while the restricted passages I0 at the outer edge of the vane or rib 9 will permit some refrigerant to by-pass around this rib, the greater portion of the refrigerating medium will flow through the helical duct III.

and durable in construction, and which is alsohighly efficient in operation. The improved casing structure may obviously be readily formed of any suitable and inexpensive sheet material, and

lthe severa1 component parts may be quickly and durably assembled and u nited as by welding or otherwise. The provisionof the space 20 between one edge of the helical rib 9 and the adjacent casing wall, not only facilitates manufacture of the casing structure by making it unnecessary to accurately and snugly fit the rib between the walls, but has also been found extremely beneficial in4 augmenting the cooling action of the refrigerant. In order to prevent the casing wall which is not secured to the adjacent edge of the rib or ribs 9 from shifting laterally during assembly of the casing 5 the free edge of the rib or ribs may be provided with small lumps or local projections of welding material or the like. thereby insuring proper centralization of the casing walls, 8, 1 and equalization in width of the space 20. While the rib 9 has been illustrated as being formed of a single helical strip of metal, it may be formed of sections, or as a series of spaced rings, but in any case the provision of the space 20 remote from the cooling surface of the casing 5 is extremely desirable. The improved casing assemblage has proven highly successful and eiiicient in actual commercial use, and can obviously be manufactured at moderate cost as compared to the prior helically wound tubular casing structures. The new casings can also be readily constructed and used for liquid congealing and ice making units of different capacities, and are far more durable than the previous aluminum casings of similar machines.

It should be understood that it is not desired to limit this invention to the exact detalls of construction, or to the precise mode of use, of the casings herein shown and described, for various modifications within the scope of the appended claims may occur to persons skilled in the art.

We claim:

l. In a refrigerating machine, an annular hollow upright casing comprising inner and outer concentric cylindrical sheet metal walls and annular upper and lower closure plates rigidly attached to the opposite end portions of said walls to form an enclosed annular refrigerant confining space of uniform width, a continuous helical sheet metal rib of uniform width interposed between said walls and having its inner edge rigidly attached to said inner wall and its outer edge slightly spaced from said outer wall while its upper and lower ends terminate short of said closure plates to provide annular unobstructed supply and discharge chambers, means for admitting refrigerant to one of said chambers and from the other through said outer wall, suspension means for said casing associated with the upper portion of said outer wall near said upper closure plate. and a rotor revolvable within said casing and having scraper blades cooperable with the inner smooth cylindrical surface of said inner wall.

2. In a refrigerating machine, an annular hollow upright casing comprising inner and outer concentric cylindrical sheet metal walls and annular upper and lower closure plates disposed between and rigidly attached to the opposite end portions of said walls to form an enclosed annular refrigerant confining space of uniform width, a

" short of said closure plates to provide annular unobstructed supply and discharge .chambers. tangential pipes for admitting refrigerant to one of said chambers and from the other through said outer wall, a suspension flange ior said casing rigidly attached to the upper portion of said outer wall near said upper closure plate, and a rotor.

revolvable within said casing and having scraper blades cooperable with the inner smooth cylindrical surface oi' said inner wall.

ERNEST F. VILTER. STEPHEN A. HUBTY.

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