Cooling apparatus and method of using the same

Abstract

A rapid cooling system for processing food is disclosed which includes a heat exchanger adapted to receive a first coolant (Coolant-I) at a first temperature and eject Coolant-I at a second temperature, a cooling chamber disposed within the heat exchanger in thermal communication with the heat exchanger, the cooling chamber includes a first inlet adapted to receive a product at an elevated temperature (T1), a second inlet adapted to receive a second coolant (Coolant-II) at a low temperature (T2), and an outlet adapted to release a combination of the product and Coolant-II at a low temperature (T.sub.out) and pressure (P.sub.out), wherein cooling of the product from T1 to T.sub.out does not cause a phase change in the product.

Claims

1. A rapid cooling system for processing food, comprising: a heat exchanger adapted to receive a first coolant (Coolant-I) at a first temperature and eject Coolant-I at a second temperature, a cooling chamber disposed within the heat exchanger in thermal communication with the heat exchanger, the cooling chamber comprising: a first inlet adapted to receive a product at an elevated temperature (T1); a second inlet adapted to receive a second coolant (Coolant-II) at a low temperature (T2); an outlet adapted to release a combination of the product and Coolant-II at a low temperature (T.sub.out) and pressure (P.sub.out), wherein cooling of the product from T1 to T.sub.out does not cause a phase change in the product and Coolant-II, and wherein Coolant-II is recirculated from the outlet to the second inlet.

2. The rapid cooling system of claim 1, wherein the first inlet of the cooling chamber is a nozzle.

3. The rapid cooling system of claim 2, wherein pressure at the nozzle is between about 80 psi and about 5000 psi.

4. The rapid cooling system of claim 3, wherein temperature at the nozzle (T1) is between about 150° F. and about 310° F.

5. The rapid cooling system of claim 4, wherein T.sub.out is between about 40° F. and about 180° F.

6. The rapid cooling system of claim 4, wherein P.sub.out is between about 10 psi and about 5000 psi.

7. The rapid cooling system of claim 1, wherein Coolant-II is introduced into the cooling chamber at a pressure PC.sub.in between about 80 psi and about 5000 psi.

8. The rapid cooling system of claim 7, wherein the release of Coolant-II through the second inlet purges gases and liquids out of the cooling chamber prior to the introduction of the product into the cooling chamber through the first inlet.

9. The rapid cooling system of claim 7, further comprising: a product-coolant separation chamber, adapted to receive the combination of the product and Coolant-II at T.sub.out from the outlet of the cooling chamber, the product-coolant separation chamber comprising: a product compartment adapted to hold the product at or about T.sub.out separated from Coolant-II; and a coolant compartment where Coolant-II at or about T.sub.out is separated from the product.

10. The rapid cooling system of claim 9, further comprising: a chiller configured to receive Coolant-II at or about T.sub.out and cool Coolant-II to about T2; and a compressor configured to pressurize Coolant-II from about P.sub.out to about PC.sub.in.

11. A method of rapidly cooling food products in food-processing, comprising: inletting a first coolant (Coolant-I) at a first temperature into a heat exchanger; ejecting Coolant-I at a second temperature from the heat exchanger; inletting a product at an elevated temperature (T1) via a first inlet into a cooling chamber in thermal communication with the heat exchanger; inletting a second coolant (Coolant-II) at a low temperature (T2) via a second inlet into the cooling chamber; releasing a combination of the product and Coolant-II at a low temperature (T.sub.out) and pressure (P.sub.out) via an outlet from the cooling chamber; and recirculating Coolant-II from the outlet to the second inlet, wherein cooling of the product from T1 to T.sub.out does not cause a phase change in the product and Coolant-II.

12. The method of claim 11, wherein the first inlet of the cooling chamber is a nozzle.

13. The method of claim 12, wherein pressure at the nozzle is between about 80 psi and about 5000 psi.

14. The method of claim 13, wherein temperature at the nozzle (T1) is between about 150° F. and about 310° F.

15. The method of claim 14, wherein T.sub.out is between about 40° F. and about 180° F.

16. The method of claim 14, wherein P.sub.out is between about 10 psi and about 5000 psi.

17. The method of claim 11, wherein Coolant-II is introduced into the cooling chamber at a pressure PC.sub.in between about 80 psi and about 5000 psi.

18. The method of claim 17, wherein the release of Coolant-II through the second inlet purges gases and liquids out of the cooling chamber prior to the introduction of the product into the cooling chamber through the first inlet.

19. The method of claim 17, further comprising: collecting the product and Coolant-II at T.sub.out from the outlet of the cooling chamber into a product-coolant separation chamber; separating the product from Coolant-II in a product compartment at or about T.sub.out; and colleting Coolant-II at or about T.sub.out in a coolant compartment.

20. The method of claim 19, further comprising: chilling Coolant-II from at or about T.sub.out to about T2; and compressing Coolant-II from about P.sub.out to about PC.sub.in.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a graph of time in min vs. temperature in ° C. which represents the effect of time and temperature on spore destruction and retention of quality in food products.

(2) FIG. 2 is a schematic of a rapid cooling system, according to the present disclosure.

DETAILED DESCRIPTION

(3) For the purposes of promoting an understanding of the principles of the present disclosure, reference will now be made to the embodiments illustrated in the drawings, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of this disclosure is thereby intended.

(4) In the present disclosure, the term “about” can allow for a degree of variability in a value or range, for example, within 10%, within 5%, or within 1% of a stated value or of a stated limit of a range.

(5) In the present disclosure, the term “substantially” can allow for a degree of variability in a value or range, for example, within 90%, within 95%, or within 99% of a stated value or of a stated limit of a range.

(6) A novel approach in cooling or rapid cooling foods that have been heated for the purpose of destroying microorganisms is presented that avoids a phase change in the product during the cooling process. The rapid cooling technology of the present disclosure (RCT) provides an effective and fast cooling of heated food products in the liquid form. The RCT can be integrated with existing aseptic systems as well as could be standalone system. RCT can be used with any aseptic system with traditional tubular heat exchanger, microwave heating or ohmic heating. In combination with the microwave technology for continuous flow systems, RCT is the only option to obtain effective overall quality of the food product.

(7) The RCT is adapted to process fruit and vegetable products. Referring to FIG. 2, a schematic diagram of the RCT system 100 according to the present disclosure is provided. The RCT system 100 includes a cooling compartment 110 and a product-coolant separation chamber 120. The cooling compartment 110 is divided into a heat exchanger 112, a cooling chamber 114, a chiller 130, and a compressor 140. The heat exchanger 112 includes an inlet 113.sub.i adapted to allow a first coolant at a low temperature 102.sub.i into the heat exchange 112 and an outlet 113.sub.o adapted to allow Coolant-I at a high temperature 102.sub.o out. The cooling chamber 114 also includes inlets and outlets. In particular, the cooling chamber 114 includes an inlet 116 adapted to allow product to be cooled at a high temperature 104.sub.i into the cooling chamber 114. The cooling chamber 114 also includes an inlet 118 adapted to allow a second coolant (Coolant-II) at a low temperature-high pressure 106.sub.i into the cooling chamber 114. The cooling chamber 114 also includes an outlet 119 adapted to allow product mixed with Coolant-II at a cooled temperature 105.sub.o out of the cooling chamber 114.

(8) The RCT system 100 also includes the product-coolant separation chamber 120. The product-coolant separation chamber 120 includes two compartment: a product compartment 122 and a coolant compartment 124 where Coolant-II is separated from the product. The product-coolant separation chamber 120 includes an inlet 122.sub.i adapted to allow the product mixed with Coolant-II at a cooled temperature 105.sub.o into the product compartment 122. The product compartment also includes an outlet 122.sub.o adapted to allow product at a low temperature 104.sub.o out. The coolant compartment 124 allows Coolant-II to be separated from the product mixed with Coolant-II at a cooled temperature 105.sub.o. The coolant compartment 124 includes an outlet 124.sub.o adapted to allow Coolant-II at a high temperature 106.sub.o to leave the coolant compartment 124.

(9) The RCT system 100 also includes the chiller 130. The chiller 130 is adapted to receive the Coolant-II at a high temperature 106.sub.o and cool and outlet the Coolant-II at a low temperature-low pressure 106.sub.m. The RCT system 100 also includes the compressor 140. The compressor 140 is adapted to receive the Coolant-II at a low temperature-low pressure 106.sub.m and pressurize and outlet the Coolant-II at a low temperature-high pressure 106.sub.i to be injected into the cooling chamber 114.

(10) Also, the RCT system 100 includes a second chiller (not shown) and a second compressor (not shown) adapted together to receive the Coolant-I at a high temperature 102.sub.o and cool and outlet the Coolant-I at a low temperature 102.sub.i to be used by the heat exchanger 112.

(11) The product at a high temperature 104.sub.i enters into the cooling chamber 114 through a nozzle located at the inlet 116. The temperature and pressure at the nozzle are in the range of aseptic processing of between about 150° F. to about 310° F. and between about 80 psi to about 5000 psi, respectively. In order to improve the efficiency of the cooling, inlet 118 allows pressurized Coolant-II at a low temperature-high pressure 106.sub.i into the cooling chamber 114. Coolant-II consists of an inert gas, e.g., nitrogen, at temperatures that will rapidly cool but not freeze the product (i.e., change the phase of the product). The RCT system 100 is configured to allow the pressurized Coolant-II at a low temperature-high pressure 106.sub.i into the cooling chamber 114 to i) displace unwanted gases (e.g., gases that can oxidize the product); and ii) provide a positive pressure for the Product+Coolant-II to exit from the outlet 119.

(12) The governing heat transfer are defined by the following equations:

(13) $\rho C_p\frac{\partial T}{\partial t}+\rho C_{p}u.Math.\nabla T+\nabla .Math.q=Q+Q_p+Q_{\mathrm{vd}}$$q=-k\nabla T,$
where
T is the temperature of the product,
C.sub.p is the specific heat capacity of the product,
ρ is the density of the product,
u is the fluid dynamic viscosity of the product,
Q is the thermal energy of the product,
Q.sub.p is the pressure work of the product,
Q.sub.vd is the viscous dissipation of the product, and
q is the heat flux of the product. Convective heat flux boundaries at all product/Coolant-II interfaces is defined by:
q.sub.0=h.Math.(T.sub.ext−T), where
h is heat transfer coefficient, and
T.sub.ext is the product temperature. For the coupling of heat transfer with the fluid flow of the streams, following equations are used:
Laminar Flow:

(14) $\rho \frac{\partial u}{\partial t}+\rho \left(u.Math.\nabla \right)=\nabla .Math.\left[-p1+\mathrm{.Math.}\left(\nabla u+{\left(\nabla u\right)}^T\right)\right]+F$$\rho \nabla .Math.\left(u\right)=0,$
where the level-set function is defined as:

(15) $\frac{\partial \varphi }{\partial t}+\nabla .Math.\left(u\varphi \right)=\gamma \nabla .Math.\left({ϵ}_{\mathrm{ls}}\nabla \varphi -\varphi \left(1-\varphi \right)\frac{\nabla \varphi }{.Math.\nabla \varphi .Math.}\right)+F,$
where
F is body force.

(16) Those having ordinary skill in the art will recognize that numerous modifications can be made to the specific implementations described above. The implementations should not be limited to the particular limitations described. Other implementations may be possible.