US 3472043 A
Description (OCR text may contain errors)
Ocl'l 14, 1969 R. B. NEL-SON CHOCOLATE COOLER Filed March 27, 1968 United States Patent O 3,472,043 CHOCOLATE COOLER Roy Bramwell Nelson, Halifax, England, assgnor to Baker Perkins Incorporated, Saginaw, Mich. Filed Mar. 27, 1968, Ser. No. 716,482 Claims priority, application Great Britain, Apr. 5, 1967, 15,580/ 67 Int. Cl. F25d 13/06, 7/00 U.S. Cl. 62-380 4 Claims ABSTRACT OF THE DISCLOSURE A cooler for chocolates which consists of an elongated tunnel through which the chocolates are traversed by a band conveyor, the tunnel having a heat absorbing zone at its entry in which heat is absorbed from the chocolates mainly by radiation followed by an air cooling zone in which jets of cooling air are directed downwardly on to the chocolates.
This invention provides an improved cooler for chocolates, by which is to lbe understood both pieces of solid chocolates and biscuits, articles of confectionery and the like which have been enrobed in chocolate.
The cooler according to the invention comprises an elongated tunnel having a heat absorbing zone at its entry end in which heat is removed from the chocolates without subjecting them to the action of an air current and an air cooling zone situated beyond the heat absorbing zone, a conveyor band of material impervious to air for conveying chocolates through the tunnel, means for providing a cushion of air beneath the upper run of the conveyor band for cooling and supporting the band, and means in the air cooling zone for directing jets of cooling air downwardly on to the chocolates on the conveyor band.
A radiation absorbent ceiling may be provided in the heat absorbing zone and this is preferably constituted by one or more blackened plates, means being provided for circulating air over the upper surface or surfaces of said plate or plates. In the heat absorbing zone the chocolates are not subjected to cooling by a current of air but mainly as the result of absorption of heat by the plate or plates, some cooling, however, being also provided by the air cushion sustaining the conveyor. In this zone crystallisation of the chocolate occurs to an extent sufficient to enable the chocolate to withstand the action of the air jets in the following zone.
One embodiment of cooler according to the invention is illustrated in the accompanying diagrammatic drawings, in which:
FIG. 1 is a vertical section through the cooler, and
FIGS. 2 and 3 are respectively sections on the lines IIII and III-III in FIG. 1.
The cooler consists of an elongated tunnel 10, through which the chocolates 12 are carried by a conveyor band 11, supported at its ends on drums 13 and driven by a driving mechanism 14. Intermediate its ends the upper run of the band 11 is sustained by an air cushion provided by air blown into a duct 15 having an air-pervious top wall 16 of wire mesh. The band 11 is made of the polyester sold under the registered trademark Terylene impregnated with polyethylene, and its return run is indicated at 28.
Above the band 11 is a duct 17 of air-pervious material, e.g. glass bre, which extends for the full length of the tunnel apart from an initial zone 18. Air blown into the upper duct 17 is delivered downwardly onto the chocolates from the duct in a series of jets 27. Air is circulated through the ducts 15, 17 by two refrigeration modules 3,472,043 Patented Oct. 14, 1969 ice 19, each including a iilter 20 for entering air, a cooler 21 and a blower 22. The air circulation is indicated by arrows in the drawing. The top duct 17 communicates at its right-hand end with a duct 23 in the zone 18, the bottom surface of which is constituted by an impervious, blackened radiation-absorbing plate 24. The air in the duct 23 cools the upper surface of the plate 24 and is returned to the bottom duct 15 and back to the blower of the adjoining module 19 by a pipe 2S. Temperature indicators are provided at intervals along the tunnel as indicated at 29 in FIG. 2.
The chocolates enter the cooler at a temperature of approximately F. and it is preferred, as indicated in FIG. l, that the temperature of the air jets supplied by the rst module 19 should be 60 F. and that the second module 19 should supply air jets at a slightly higher temperature of 60-65 F.
Chocolate consists of a suspension of iine particles of solids, i.e. cocoa, sugar, milk, ilavouring and viscosity additives in well dispersed cocoa butter. Cocoa butter is a fat which contains tri-glycerides of several fatty acids and is capable of setting in a number of crystalline forms of which that known as the beta form is the stable one and has the highest melting range. It is accordingly important so to temper and cool chocolate as to induce the formation of tine beta form crystals.
Chocolate must be cooled efficiently but gently without causing a cold film to form around liquid chocolate. The cooler according to the invention provides for initial cooling by absorption in the zone 18 for a predetermined time, and by this we mean cooling without subjection of the chocolate to a moving current of air, apart from the con vection current between the chocolate and the cooled absorbing plate 2'4. The absorption cooling in this zone initiates gently a natural cooling and solidification pattern of stable crystal growth. High speed warmer air is thereafter directed, as the chocolates travel further through the tunnel 10, on to the top of the chocolates by air jets travelling at speeds of up to 2000 ft./min. and this breaks up the barrier layer of radiated heat extending between the individual chocolates. The air jets impinge upon the whole area of the chocolates and accordingly provide more eiective cooling than the counterow or transverse currents of cooling air, travelling at about 700 ft./min., used in conventional coolers. The air in a conventional counter-flow cooler is at a temperature of 45-50" F. and by using air jets at a temperature of 60-65 F. we are able to provide conditions favouring the growth of stable crystals.
In the conventional counter-How cooler it is necessary to raise the temperature of the chocolates to about 65 F. towards the end of the cooling tunnel to prevent condensation or sweating when they reach the ambient air. This is undesirable, since the resulting expansion of the chocolates may cause hair line cracks which permit ingress of moisture on storage. No such rise of temperature at the end of the cooler is necessary in accordance with the invention. The chocolates are cooled gently in the lirst zone 18, which is maintained at approximately 60 F. by absorption and the conduction cooling on their bottom surfaces produced by the cooled conveyor band. Gentle all round cooling is thus provided for a predeter mined time. Thereafter the chocolates are subjected to the slightly warmer air jets 27, at 60-65 F., throughout the remainder of their journey through the tunnel. The solidified crystals are in the stable beta form and good shelf life of the product is assured. While the chocolates are subjected to the air jets they continue to receive conduction cooling on their undersurfaces from the conveyor band 11.
What I claim as my invention and desire to secure by Letters Patent is:
1. A cooler for chocolates and articles enrobed in chocolate which comprises an elongated tunnel having a heat absorbing zone at its entry end in which heat is removed from the chocolates without subjecting them to the action of an air current and an air cooling zone situated beyond the heat absorbing zone, a conveyor band of materials impervious to air for conveying chocolates through the tunnel, means for providing a cushion of air beneath the upper run of the conveyor band for cooling and supporting the band, and means in the air cooling zone for directing jets of cooling air downwardly on to the chocolates on the conveyor band.
2. A cooler as claimed in claim 1, in which the heat absorbing zone has a radiation absorbent ceiling and means are provided for circulating air over the upper surface of the ceiling.
3. A cooler as claimed in claim 2, in which the cei1- ing is constituted by one or more blackened plates.
4. A cooler as claimed in any preceding claim, which comprises at least one refrigeration module, including a cooler and a blower, for circulating air through a duct composed of air-previous material which extends above the conveyor band in the air cooling zone and also through a duct disposed beneath the conveyor band and having an air-previous top wall.
References Cited UNITED STATES PATENTS 2,212,916 8/1940 Hawkins et al. 62-380 X 3,402,762 9/1968 Kreuter et al. 16S-120 X WlLLIAM E. WAYNER, Primary Examiner U.S. Cl. X.R.