MXPA97001674A - Freezer by immersion, with seriestransportadores in cascade of camera of fo - Google Patents

Abstract

The present invention relates to an immersion freezer characterized in that it comprises: (a) an insulated housing having a first end that runs horizontally to a second end, (b) a horizontal deflector that divides the housing into an upper chamber and a chamber lower, (c) a gate for entry of articles located in the upper chamber at or near the first end to introduce the items to be frozen in the freezer, (d) a coolant bath located in the upper chamber to submerge all or part of the the articles to be frozen in a liquid refrigerant; (e) an upper chamber conveyor belt to transport the articles from the article entry hatch and through the refrigerant bath to the second end; (f) a chamber transfer gate that pierces the horizontal deflector at or near the second end to allow items to fall from the conveyor belt of the upper chamber r and into the lower chamber and to allow the refrigerant evaporated from the coolant bath to move to the lower chamber; (g) a series of cascade conveyor belts located in the lower chamber, to transport the articles into the lower chamber from the second end, at the first end, and back to the second end again where the initial cascading conveyor in the series receives the articles as they fall from the upper camera conveyor belt and where each successive band in the series receives the articles fall from the preceding web, and (h) a gate for goods outlet located at the bottom of the lower chamber at or near the second end to receive the articles as they fall from the final conveyor in the series of conveyor belts in waterfall and for subsequent removal of frozen items from that frozen

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to an immersion freezer that employs a subsequent cooling chamber containing a series of cascade conveyor belts. BACKGROUND OF THE INVENTION An immersion freezer having a subsequent cooling chamber contains a series of cascade conveyor belts, illustrated in the art.

Specifically, Koach Engineering & Mfg Inc. illustrates that referred freezer, "Nitrogen Immersion-Vapor Freezing System" (below "Koach freezer") in a technical brochure entitled "Innovation and efficiency in Food Frezing Equipment" . (Innovation and efficiency of food freezing equipment). (The Koach freezer, minus the characteristic of the cascade conveyor belt, is also illustrated in U.S. Patent No. 4,403,479 by Rasovich). The immersion section of this freezer initially submerges all the part of the products to be frozen (typically foodstuffs) in a bath of a liquid refrigerant, to impart a freezing of the crust in the articles that hardens inside the humidity and prevents formation of lumps The subsequent cooling chamber then uses the vaporized refrigerant from the immersion section to complete the freezing process, while also maximizing efficiency. The subsequent cooling chamber also imparts agitation to the products (which also avoids the formation of lumps, through the use of a series of cascade conveyor belts). There is concern with the Koach freezer, however, since the location of the cooling chamber with respect to the immersion section is not optimal. In the Koach freezer, the subsequent cooling chamber is located adjacent to the immersion section. This contrasts with the freezing of the present invention, wherein the subsequent cooling chamber is located below the immersion section. This design difference imparts three distinct advantages to the freezer of the present invention as follows: (1) The "footprint" of the freezer of the present invention will be smaller and thus the freezer of the present invention will require less floor space than the freezer of the present invention. factory. (2) Since both the immersion section and the subsequent cooling chamber, in general have the shape of elongated tunnels, when "stacking" the tunnels instead of placing them adjacent to each other, not only the resulting freezer footprint is smaller but also of the exposed surface area. Since the thermal leakage of a freezer is proportional to the exposed surface area, this results in less heat leakage and therefore better efficiency. (3) Both the Koach freezer and the freezer of the present invention exploit the fact that it is space efficient for multiple steps of articles as they move through the subsequent cooling chamber. The number of multiple steps however quickly reaches a point of diminished return after one or two steps (ie beginning at one end of the subsequent cooling chamber, moving to the next extreme to create a first "level" of bands at ciascada and finally returning to the start end to create a second "level" of cascaded bands) from the point of view of thermal transfer to the product and therefore efficiency. This is because it is difficult for the evaporated coolant of the dip section to penetrate beyond the second level of cascaded bands in the subsequent cooling chamber. Because the Koach freezer cooling chamber is adjacent to the immersion section, the cascade conveyors in Koach's after-cooling chamber are forced to multiple passes three times in order to get the items finished in the outlet end of the freezer. This forces a substantially wasted third level (in terms of thermal transfer) into the Koach after-cooling chamber, which avoids the design of the bottom chamber of the present invention.

The present invention is an immersion freezer that employs a chamber of subsequent cooling. The immersion section of the freezer initially immerses all or part of the items to be frozen (typically food products) in a bath of a liquid refrigerant to impart a freezing of the crust in the products that locks in the moisture inside and prevents the formation of lumps . The subsequent localized cooling chamber underlying the immersion section then uses the vaporized refrigerant from the immersion section to complete the freezing process, while also maximizing efficiency. The subsequent cooling chamber also imparts agitation to the products (which also avoids lumping) through the use of a series of cascade conveyor belts. A key to the present invention is that the subsequent cooling chamber is located underlying the face-to-face immersion section adjacent to the dip section as the prior art. This design difference produces several advantages to the immersion freezer of the present invention, including a smaller floor space requirement and less thermal leakage. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic drawing of one embodiment of the present invention. DESCRIPTION OF THE INVENTION The freezer of the present invention is best illustrated with respect to a specific embodiment thereof such as the embodiment of Figure 1. The freezer of Figure 1 comprises: (a) an insulated housing 10 having a first end 12 which runs horizontally to a second end 14; (b) a horizontal baffle 16 that divides the housing into an upper chamber 18 and a bottom chamber 20; (c) a door for entry of articles 22 located in the upper chamber at or near the first end to introduce the articles when freezing in the freezer; (d) a coolant bath 24 located in the upper chamber for submerging all or part of the articles to be frozen in a liquid refrigerant; (e) an upper chamber conveyor belt 26 for transporting the articles from the article entry gate and through the cooling bath to the second end; (f) a chamber transfer gate 28 that pierces the horizontal baffle at or near the second end to allow falling from the conveyor belt to the upper chamber from a bottom chamber and to allow the vaporized refrigerant from the cooling bath to move to the background camera; (g) a series of cascade conveyor belts 30 located in the bottom chamber for transporting the articles within the bottom chamber from the second end, to the first end, and back to the second end again, where the conveyor belt the initial cascade in the series receives the articles as they fall from the upper chamber conveyor belt and where each successive band in the series receives the articles as they fall from the preceding band; (h) a product outlet gate 32 located at the bottom of the lower chamber at or near the second end to receive the articles as they fall from the final conveyor in the series of cascade conveyor belts and for subsequent removal of the articles frozen from the freezer; (i) at least one coolant inlet gate 34 for introducing the liquid coolant into the coolant bath; () at least one coolant discharge gate 36 for removing the evaporated coolant from the bottom chamber; and (k) at least one discharge fan 38 for directing evaporated refrigerant from the refrigerant bath to the bottom chamber and out of the refrigerant discharge port; (1) at least one incidence fan 40, for directing the evaporated refrigerant in the bottom chamber at high speed and in a direction substantially perpendicular to the movement of the products through the bottom chamber; and (m) at least one circulation fan 42 for directing the evaporated refrigerant in the bottom chamber, in a substantial direction parallel to the movement of the products through the bottom chamber. It will be noted that a preferred embodiment of the dipper section of the upper chamber of the present invention and the introduction of liquid refrigerant into the coolant bath is as illustrated by US Pat. No. 5,417,074 by Kiczec et al., The specification of which is incorporated herein by reference. It will also be noted that the amount of cascaded conveyor belts in the series of these bands of the present invention will be a function of how much product agitation is desired (to avoid clumping). In most cases, two bands in series will be sufficient, which is the modality illustrated in Figure 1. In this mode, the initial cascade band receives the products as they fall from the upper chamber conveyor belt and transports the products from the second end to the first end, while the final cascade band receives the products as they fall from the initial cascade band and transports the products back to the second end. This modality provides three different agitation points as follows: (i) 1 point where the products can be from the upper chamber band to the initial cascade band; (ii) the point at which the articles or products fall from the initial cascade band to the final cascade band; and finally (iii) the point where the products fall from the final cascade band to the output gate of the product. If more agitation is required, the series of cascade conveyor belts can persist from a large number of shorter bands to transport the products within the bottom chamber from the second end, to the first end, and back to the second end again. . Finally, it should be noted that a preferred refrigerant for the freezer of the present invention is nitrogen.

Claims (4)

1. CLAIMS 1.- An immersion freezer comprises: (a) an isolated housing having a first end that runs horizontally between a second end; (b) a horizontal baffle that divides the housing into an upper chamber and a bottom chamber; (c) a gate for entry of articles located in the upper chamber at or near a first end to introduce the articles when freezing in the freezer; (d) a coolant bath located in the upper chamber to submerge all or part of the articles to be frozen in a liquid refrigerant; (e) an upper chamber conveyor belt for transporting the articles from the article entry hatch and through the cooling bath of the second end; (f) a chamber transfer gate that pierces the horizontal baffle at or near the second end to allow falling from the conveyor belt to the upper chamber from a bottom chamber and to allow the vaporized refrigerant from the cooling bath to move to the upper chamber from a bottom chamber. the background camera; (g) a series of cascade conveyor belts located in the bottom chamber, for transporting the articles within the bottom chamber from the second end, to the first end, and back to the second end again where the conveyor in the initial cascade in the series receives the articles as they fall from the upper chamber conveyor belt and where each successive band in the series receives the articles as they fall from the preceding band; (h) a product outlet gate located in the bottom of the lower chamber at or near the second end to receive the articles as they fall from the final conveyor in the series of cascade conveyors and for subsequent removal of the frozen articles of that freezer.
2. 2. The immersion freezer according to claim 1, characterized in that it further comprises: (i) at least one gate for the admission of refrigerant to introduce the liquid refrigerant to the coolant bath; (j) at least one coolant discharge gate for removing the evaporated coolant from the bottom chamber; and (k) at least one discharge fan for directing evaporated refrigerant from the refrigerant bath to the bottom chamber and out of the refrigerant discharge port; (1) at least one incidence fan, for directing the evaporated refrigerant in the bottom chamber at high speed and in a direction substantially perpendicular to the movement of the products through the bottom chamber; and () at least one circulation fan for directing the evaporated refrigerant in the bottom chamber in a direction substantially parallel to the movement of the products through the bottom chamber.
3. 3. The immersion freezer according to claim 2, characterized in that the series of conveyor belts in cascade in the bottom chamber consists of two belts, the two belts being the initial cascade conveyor belt receiving the articles as they fall from the upper chamber conveyor belt and transport the articles from the second end to the first end and a final cascade conveyor belt which receives the articles as they fall from the initial cascade conveyor belt and transports the articles back to the second end.
4. 4. The immersion freezer according to claim 3, characterized in that the liquid refrigerant introduced into the coolant bath is liquid nitrogen.