Method & Apparatus for making wet snow

Abstract

A method and apparatus is described that makes wet snow from ice-slurry. The method and apparatus described further delivers wet snow as produced onto the surface and into the cavities of perishable products, such as animal carcasses, where it adheres and melts slowly, thereby resulting in rapid cooling and in case of food products, leading to improved quality and shelf life of the food. The method and apparatus described can also be used to separate ice and liquid from ice-slurry made of wastewater.

Claims

1. A method for manufacturing wet snow comprising: making ice-slurry in an ice-slurry generator and pumping ice-slurry from a supply to a wet snow making system; operating a wet snow making system, composed of a wet snow making apparatus with at least one filter unit, having a conically shaped porous filter housing within a wet snow-making chamber of wet snow making apparatus; feeding of ice-slurry from a supply trough at least one inlet into a conical filter unit chamber inside wet snow-making apparatus; impacting the ice-slurry by air pressure trough at least one inlet and filtering the ice-slurry in a conically shaped filter housing inside wet snow-making apparatus; discharging wet snow with air pressure from at least one outlet of a wet snow-making apparatus.

2. A method as claimed in claim 1, wherein ice-slurry can contain 0.05 to 25% salt such as NaCl, preferably 1 to 15% NaCl, even more preferably 2 to 10% NaCl.

3. A method as claimed in claim 1, wherein wet snow discharged from a wet snow making apparatus and onto a specific target is characterized in that: wet snow can contain 30 to 90% ice, preferably 40 to 80% ice, even more preferably 45 to 75% ice; wet snow discharged can contain 0.01 to 10% salt, preferably 0.05 to 5% salt, even more preferably 0.1 to 2% salt; wet snow discharged is at temperature of 0 to 20 C., preferably at temperature of 1 to 10 C., even more preferably at temperature of 2 to 5 C.

4. A method as claimed in claim 1, wherein a conical shaped filter housing within a wet snow-making chamber of a wet snow making apparatus is in the form of a truncated cone or conical frustum, and shaped as a right circular cone with an apex angle between 140 to 179.9 degrees, preferably between 160 to 179.5 degrees, even more preferably between 170 to 179 degrees.

5. A method as claimed in claim 1, wherein the ice-slurry enters a conical filter housing through the narrow opening or aperture end, of a conical filter and wet snow is discharged through the wide opening or base end of a conical filter.

6. A wet snow making apparatus comprising: a wet snow making chamber having at least one inlet to receive ice-slurry from a supply and at least one outlet for the discharge of wet snow; at least one conically shaped filter housing within a wet snow-making chamber of a wet snow making apparatus; where the apex of the conically shaped filter housing is directed against the flow of the ice-slurry; at least one inlet for pressured air for impacting the ice-slurry and filtering the ice-slurry in a conically shaped filter unit chamber inside a wet snow-making apparatus and converting ice-slurry into wet snow; at least one outlet for discharge of the liquid filtered through conically shaped filter housing, collecting liquid and transferring liquid out of wet snow-making apparatus.

7. An apparatus as claimed in claim 6, wherein the filter housing within a wet snow-making chamber of a wet snow making apparatus is conically shaped in the form of a truncated cone or conical frustum, and shaped as a right circular cone; where the apex angle of the truncated cone is in the range of 140 to 179.9 degrees, more preferably in the range of 160 to 179.5 degrees, most preferably in the range of 170 to 179 degrees.

8. An apparatus according to claim 6, wherein the inside volume of wet snow making chamber is between 5 to 500 ml and where processing frequency is in a range of 10 to 200 shots of wet snow per minute, even more preferably where the inside volume of the chamber is between 20 to 150 ml and where processing frequency is in a range of 20 to 60 shots of wet snow per minute.

9. A system for producing wet snow comprising: ice-slurry from an ice-slurry generator or from a supply of ice-slurry; a wet snow making apparatus comprising: a wet snow making chamber having at least one inlet to receive ice-slurry from a supply and at least one outlet for the discharge of wet snow; at least one conically shaped filter housing within a wet snow-making chamber of a wet snow making apparatus; where the apex of the conically shaped filter housing is directed against the flow of the ice-slurry; at least one inlet for pressured air for impacting the ice-slurry and filtering the ice-slurry in a conically shaped filter unit chamber inside a wet snow-making apparatus and converting ice-slurry into wet snow; at least one outlet for discharge of the liquid filtered through conically shaped filter housing, collecting liquid and transferring liquid out of wet snow-making apparatus; an ice-slurry transfer apparatus to transfer ice-slurry to inlet of a wet snow making apparatus, and a wet snow transfer apparatus powered by pressured air to transfer wet snow that is discharged out of wet snow making apparatus, and where the opening of inlet for ice-slurry and for discharge of wet snow are controlled by valves a wet snow making apparatus fitted with various controllable valves and monitoring devices available to those skilled in the art and said valves being powered by air pressure and monitoring devices being controlled and run by electronic means such a by a computer.

10. An apparatus according to claim 6, made by and from any number of different materials available to those skilled in the art, such as metals, organic materials or synthetic materials such as steel, rubber or plastics.

11. An apparatus according to claim 6, where different forces can be brought into or applied to the different inlets and outlets, such as to bring the ice-slurry into the chamber or to apply pressurized air or vacuum to the chamber according to claim 1 and the extent and frequency of such applications are controlled by electronic means such a by a computer.

12. A system according to claim 9 where ice-slurry can be made of a fluid that is aqueous, or substantially aqueous, containing different solutes, such as salts, sugars or alcohols in different concentrations.

13. A system according to claim 9 where ice-slurry can be made of a fluid that is prepared from polluted water streams, including, but not limited to animal urine, such as pig urine or wastewater from food processing, milk processing, fish processing or various other industries that produce wastewater containing solutes of inorganic or organic nature.

14. A system according to claim 13 where ice-slurry is made from a polluted wastewater and where an apparatus and method when operated as described, thereby performs a chemical separation action where the resulting wet snow contains lower solute concentration than was in original polluted wastewater, and drained liquid produced contains higher solute concentration than was in original polluted wastewater.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0041] FIG. 1A shows a drawing of the apparatus in a transection view with the conical filter unit, closing valves and inlet and outlet pipes for different functions. FIG. 1B shows the position when loading the apparatus with ice-slurry, FIG. 1C shows the position when both inlet and outlet (discharge) valves are closed and filtering takes place, FIG. 1D shows the position when discharging (shooting) the wet snow out of the apparatus.

[0042] FIG. 2 shows a photograph of the apparatus being applied for cooling fresh chicken on a conveyer belt in real-life commercial settings. The figure shows a real-life photograph of using a prototype apparatus of the invention to deliver the wet snow onto the surface of chicken carcass on a conveyer belt. The chicken was treated in a commercial setting after it had been through a feather picking machine at 57 C., from where it goes onto the conveyer belt for removing of internal organs and opening of the neck along with the repeated washing in between. The chicken then enters the cooling room where it is normally cooled by cold air and cold water spraying. It is possible to station the apparatus of the invention at several places during this process. In this example the chickens were treated inside the cooling room on the conveyer belt for the controlled demonstration.

[0043] FIG. 3 shows the cooling efficiency when wet snow of the invention is used for cooling a whole chicken carcass as shown in FIG. 2, compared to conventional cooling by a combined cold blast air and cold water spray. The figure shows a temperature tracing of the internal temperature in the breast of the chickens shown in FIG. 2 when treated with wet snow of the invention. A similar temperature tracing is shown for a whole chicken carcass when cooled by the traditional method of the commercial settings using cold air blowing and cold water spraying.

[0044] FIG. 4 shows the cooling efficiency when we snow of the invention is used for cooling a part of a fish as compared to conventional cooling by spraying with cold water or by soaking into a tank with normal ice-slurry.

DETAILED DESCRIPTION OF THE INVENTION

[0045] As described herein, the invention is used to make wet snow by separating ice and liquid from an ice-slurry in an efficient and continuous way and thereby delivering the so produced wet snow for use in rapid chilling of perishable products, such as meat and fish. The invention can also be used for desalination and for concentration of solutes from polluted wastewater such as animal urine. The preferred embodiments of the invention adapted for continuously cooling food products, will now be described in details with reference to the drawings and figures provided.

[0046] Unless defined otherwise, all technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are now described.

Example 1

[0047] This example shows drawings of the apparatus of the invention. FIG. 1A shows a transection through the prototype version of the invention. The function of the individual parts as numbered in the drawing in FIG. 1 are explained according to the following list:

1. Intake tube for pumping of ice-slurry into main chamber of the apparatus.
2. Pinch valve for controlling the intake of ice-slurry into main process chamber
3. Cavity of main process chamber housing the porous conical filter unit #5.
4. External shell wall of the main process chamber.
5. Conical filter unit with apex facing the direction of flow and the conical filter unit gets filled with ice-slurry upon opening of pinch valve #2.
6. Inlet for attaching air-tube for putting air pressure inside the filter unit by opening of air valve.
7. Cavity between the porous filter shell #5 and the and the external shell wall #4
8. Outlet for removing the liquid pressed from the ice-slurry through the filter in the conical filter unit #5 into the cavity #7, using air or solenoid valve for one or two directional flow.
9. Pinch valve for controlling the shooting of wet snow out of the conical filter unit and upon opening for simultaneous air valve to allow air pressure through inlet #6.
10. Outlet opening or tube directing shooting of the wet snow onto target.
11. Inlet for additional operations if needed, such as more suction/vacuum/pressure to further dewatering, or adding water to wash the wet snow or to increase the temperature of the wet snow, or adding brine with higher salt concentration to lower the temperature of the wet snow, or to clean the filter by administering a washing liquid with reverse flow action.
Position 1 shown in FIG. 1B is when inlet valve is open for loading the apparatus with ice-slurry.
Position 2 shown in FIG. 1C is when both inlet and outlet (discharge) valves are closed and filtering takes place.
Position 3 shown in FIG. 1D is when outlet valve is open for discharging (shooting) the wet snow out of the apparatus.

Example 2

[0048] This example demonstrates the use of the invention for cooling chicken carcass on a conveyer belt. FIG. 2 shows a photograph of a prototype testing of the apparatus in real-life commercial setting. It shows how the wet snow can be delivered to different places and cavities of a chicken carcass where it adheres and then melts slowly and thereby cooling the carcass.

Example 3

[0049] This example demonstrates the use of the invention for cooling chicken carcass on a conveyer belt. FIG. 3 shows the temperature tracing of a chicken chilled with the invention as viewed in the operation in FIG. 2 and how the wet snow can be delivered to different places and cavities of a chicken carcass where it adheres and melts slowly and thereby cooling the carcass. In this example most of the experiments were done by using incoming ice-slurry with about 25% ice and made from a salt solution containing 3.5 to 7% NaCl. Test have also been successfully done with wet snow of about 30% ice to about 85% ice, and also with nearly saturated NaCl solution, with temperatures as low as 20 C. The wet snow as produced by the invention can deliver wet snow over a wide range of ice percent content, or from 30% to at least 90% ice and at temperatures from about 0.5 C. to about 15 C.

Example 4

[0050] This example demonstrates the use of the invention for cooling a part of a fish with wet snow, after the fish had been cut and was traveling along a conveyor belt in a commercial fish processing factory. Enough wet snow was delivered on top of the fish part to cover about 30-70% of the fish part with about 5 mm layer of ice-slurry of the invention. The ambient temperature in the factory was about 9 C. when the experiment was done. At the same time fish parts were also cooled with two types of traditional cooling methods, i.e. spraying with about 5 liters of cold water with 0.2% salt in order to reach 0 C. and immersing the fish part into a plastic box with ice-slurry as produced before filtering and as normally used in the factory. The measurements were done using the parts of fresh cod cut from the same section of the cod in all cases and ranging from 270 grams to 310 grams. The temperature was measured in the core muscle of the fish using calibrated thermometers. FIG. 4 shows temperature tracings of the internal temperature in the fish parts when comparing the use of wet snow of the invention and two traditional methods.

[0051] It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present invention and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.