GB2238606A

GB2238606A - Cooling flowable food products

Info

Publication number: GB2238606A
Application number: GB9025177A
Authority: GB
Inventors: David A Norris
Original assignee: DC Norris and Co Engineering Ltd
Current assignee: DC Norris and Co Engineering Ltd
Priority date: 1989-05-18
Filing date: 1990-11-20
Publication date: 1991-06-05
Anticipated expiration: 2010-11-20
Also published as: GB2238606B; GB9025177D0

Abstract

A holding tank for flowable food product is cooled by an agitator 93 having hollow vanes 94 through which coolant flows. The agitator is rotatably mounted on a cover 91 which can be lowered on to the tank. A motor 98 rotates the agitator. The vanes 94 carry scrapers 97. Concentric ducts 95, 96 conduct coolant (ethylene glycol) to the bases of the vanes and withdraw it from the tops of them. Coolant can also be supplied to a hollow wall of the tank. At a cooling station (Fig 5) a tank is wheeled into position, its lid opened, a cooling/agitating unit lowered into the tank and coolant connections made. The tank contents are cooled until sensors detect that a required temperature has been reached. The coolant passages are purged with air, and the unit lifted clear of the tank. <IMAGE>

Description

COOLING APPARATUS Flowable food products may be dispensed from a holding tank under pressure as, for example, disclosed in patent specification No. 2 232 210A. It is sometimes desired to cool the food product before dispensing it, and the cooling apparatus described hereinafter has been found to be advantageous for this purpose.

In the drawings: Figure 1 is a section through a food holding tank at a cooling station, Figure 2 is a cross-section on line X-X in Figure 1, Figure 3 is a side elevation of a cooling station, Figure 4 is a side elevation of tank in a cooling booth, Figure 5 illustrates schematically a bank of cooling booths and associated circuits.

Figure 6 is a graph to illustrate the cooling effect of a booth shown in Figures 4 and 5.

Reference should be made to patent specification No.

2 232 210A for details of some types of food holding tank which may be used in connection with the cooling apparatus to which the present invention relates.

To facilitate the cooling of food product within a tank of the type shown at 1 in Figure 1 of that specification, the tank may be moved to a cooling station at which the hinged lid of the tank (if provided) may be swung back, and a cooling unit lowered into the tank as shown in Figure 1. The cooling unit includes a cover 91 which rests on the tank when the cooling unit is in its lowered position. Journal led in the cover is a shaft 92 of an agitator 93. The agitator includes hollow vanes 94, and the shaft has concentric inner and outer ducts 95, 96 through which coolant (conveniently in the form of ethylene glycol) may be supplied to the lower end of the vanes and withdrawn from their upper ends. The vanes are generally elliptical in cross-section and angled relative to the wall of the tank so that, on rotation, the contents of the tank flow over the leading surfaces of the vanes.The tank has a hollow wall through which the coolant may be passed, and lower and upper ports to which coolant supply and outlet hoses (not shown) may be attached when the tank is at the cooling station.

Scrapers 97 on the vanes dislodge food product from the inner wall of the tank and force it into circulation within the tank so as to promote cooling of the tank contents by contact with the tank wall. Drive means 98 are provided for rotating the vanes, and ducts 99 serve to conduct coolant to and from the agitator. As shown in Figure 3, the cover 91 may be provided with vertically extending hollow posts 100 through which the ducts 99 pass. The posts are guided for vertical movement between wheels 103 mounted on a framework 101 depending from crossbeams 102 of the factory structure. A motor 104 operates gearing for raising and lowering a screw 105 connected to a crosspiece welded to the posts 100. In a modification, the screw is replaced by a fluid-operated ram.

Referring to Figures 4 and 5, a cooling station takes the form of a group of three booths into which the tanks may be wheeled. When in position, coolant supply and outlet hoses 110 are connected to the lower and upper ports respectively in the jacket of the tank, the cover 91 opened and the cooling unit lowered under the action of pneumatic cylinders or electrical drive means controlled by an operator using an adjacent switch panel. Valves B and C are opened and ethylene glycol circulated through the cooling unit and jacket (which has helical vanes to guide the coolant - see Figure 1) from the storage tank 111 through lines 112, 113 until the temperature of the food product has fallen to the desired level. The temperature of the surface of the food product is monitored by an infrared thermostat directed at the surface. Means responsive to the thermostat serve to close the valves B and C to terminate the cooling operation and open solenoid valve E and valve A to admit scavenging air to the circuit in the reverse flow direction from line 114 to drive the coolant into the expansion tank through line 115. A non-return valve D prevents the scavenging air entering the circuit through the cooling unit. Following extraction of the cooling unit, the cover is replaced, the hoses disconnected and the tank wheeled to the filling line for discharge of the food product as described in the above-mentioned specification. The construction and operation of the cooling unit is generally as described with reference to Figures 1 to 3. Figure 6 is a graph showing the rate at which cooling may take place using the proposed apparatus.

Claims

1. Apparatus for cooling food product within a movable holding tank, including a cover for the tank, a rotatable cooling unit extending downwards from the cover, means for driving the cooling unit in rotation, and means for supplying coolant to the cooling unit.

2. Apparatus as claimed in claim 1, wherein the cooling unit includes hollow vanes for the passage of coolant.

3. Apparatus as claimed in claim 1, including heat detecting means associated with the cooling unit for monitoring the temperature of the food product.

4. Apparatus as claimed in claim 1, including means for raising and lowering the cooling unit.

5. Apparatus as claimed in claim 1, including a coolant supply circuit connected to the cooling unit and connectable to a cooling jacket of the tank.

6. Apparatus as claimed in claim 5, including means for admitting scavenging air to the coolant circuit.

7. A holding tank for flowable food product to which is attached or attachable a lid provided or providable with an extraction tube; the extraction tube being insertable into the tank when the lid is in a closed position on the tank, in combination with cooling apparatus including a cover for the tank, an agitator extending downwards from the underside of the cover, means on the cover for driving the agitator in rotation; the agitator including a hollow drive shaft and hollow vanes, and means for passing coolant through the shaft and vanes; and a vertically movable support structure for the cooling apparatus.