Pasteurization system and method

• US 20110023728A1
• Filed: 07/29/2009
• Published: 02/03/2011
• Est. Priority Date: 07/29/2009
• Status: Active Grant

• Current Assignee: Tokitae LLC (Intellectual Ventures LLC)
• Original Assignee: Searete LLC (Intellectual Ventures LLC)
• Inventors: Myhrvold, Nathan P., Yildirim, Ozgur, Gates, William, Wood, Lowell L. JR., Hyde, Roderick A., Deane, Geoffrey F., Kare, Jordin T., Tuckerman, David B.
• Granted Patent: US 9,930,898 B2
• Time in Patent Office: Days
• US Class Current: 99/483
• CPC Class Codes: A23C 3/0332 in contact with multiple heating plates
• CPC Class Codes: A23C 3/0335 the milk being heated by electrical or mechanical means, e.g. by friction
• CPC Class Codes: A23L 3/003 Control or safety devices for sterilisation or pasteurisation systems
• CPC Class Codes: A23L 3/22 with transport through tubes
• CPC Class Codes: C12H 1/18 by heating

Abstract

A pasteurization system includes a liquid inlet configured to receive a liquid to be pasteurized. The system also includes a pump coupled to the liquid inlet for pressurizing the liquid. Further, the system includes a counter flow heat exchanger coupled to the liquid inlet and the pump, the counterflow heat exchanger configured to heat the liquid to a predetermined temperature for at least a predetermined time and configured to exchange heat between a flow of liquid in a first direction in a first channel with the flow of liquid in a second direction opposite the first direction in a second channel. A heating section that heats the liquid flow is integrated into the heat exchanger and heats at least a portion of the first channel or the second channel.

Claims

1. A pasteurization system, comprising:

a liquid inlet configured to receive a liquid to be pasteurized;

a pump coupled to the liquid inlet for pressurizing the liquid; and

a counter flow heat exchanger coupled to the liquid inlet and the pump, the counterflow heat exchanger configured to heat the liquid to a predetermined temperature for at least a predetermined time and configured to exchange heat between a flow of liquid in a first direction in a first channel with the flow of liquid in a second direction opposite the first direction in a second channel, a heating section that heats the liquid flow is integrated into the heat exchanger and heats at least a portion of the first channel or the second channel.

2. The pasteurization system of claim 1, wherein the first channel and the second channel are separated by a thin wall.

3. The pasteurization system of claim 1, wherein the first channel and the second channel are separated by a thin wall and the thin wall has a thickness less than 0.01 centimeters.

4. The pasteurization system of claim 1, wherein the first channel and the second channel are separated by a thin wall and the thin wall has a thickness less than 0.002 centimeters.

5. The pasteurization system of claim 1, wherein the first channel and the second channel share a wall.

6. The pasteurization system of claim 1, wherein the first channel and the second channel share a wall and there exist multiple pairs of input channels and output channels in a row each pair sharing a wall with an adjacent pair.

7. The pasteurization system of claim 1, wherein the pasteurizer recovers at least 90% of the peak thermal energy of the liquid.

8. The pasteurization system of claim 1, wherein the first channel and the second channel share a wall, the input and output channels being at least partially surrounded by an insulating layer.

9. The pasteurization system of claim 1, wherein the first and second channels each having a hydraulic diameter, expressed as four times the cross sectional area of the channel divided by the perimeter of the cross section, that is less than approximately one millimeter.

10. The pasteurization system of claim 1, wherein the first and second channels each having a hydraulic diameter, expressed as four times the cross sectional area of the channel divided by the perimeter of the cross section, that is less than approximately one hundred micrometers.

11. The pasteurization system of claim 1, wherein the first channel and the second channel are at least partially formed of polyaryletheretherketone (PEEK).

12. The food product sterilizer of claim 1, wherein the heating section includes an electric heater.

13. The pasteurization system of claim 1, wherein the heating section includes a heater and includes a highly thermally conductive material between the heater and the channel.

14. The pasteurization system of claim 1, wherein the heating section includes a heater and includes a highly thermally conductive material between the heater and the channel, the highly thermally conductive material including copper.

15. The pasteurization system of claim 1, wherein the liquid includes at least one of fruit juice, apple cider, honey, maple syrup, milk, soy sauce, sports drinks, vinegar, water, wine, beer, cream, and cheese.

16. The pasteurization system of claim 1, further comprising a filter configured to filter the liquid.

17. The pasteurization system of claim 1, further comprising a sensor configured to sense at least one characteristic of the liquid.

18. The pasteurization system of claim 1, further comprising a sensor configured to sense at least one characteristic of the liquid, wherein the sensor is a temperature transducer.

19. The pasteurization system of claim 1, further comprising a sensor configured to sense at least one characteristic of the liquid, wherein the sensor includes a pressure transducer.

20. The pasteurization system of claim 1, further comprising a sensor configured to sense at least one characteristic of the liquid, wherein the sensor includes a flow transducer.

21. The pasteurization system of claim 1, wherein the first channel and the second channels are microchannels.

22. The pasteurization system of claim 1, wherein the first channel and the second channels are configured with aspect ratios which encourage laminar flow.

23. The pasteurization system of claim 1, wherein the first channel and the second channels are configured to induce liquid flow in the channel with a Reynolds number of less than 2000.

24. The pasteurization system of claim 1, wherein the first channel and the second channels are configured to induce liquid flow in the channel with a boundary layer thickness that is greater than one-half the thickness of the channel.

25. The pasteurization system of claim 1, further comprising an insulative layer, the insulative layer at least partially insulating the first channel, the second channel, and the heating section.

26. The pasteurization system of claim 1, wherein the heat exchanger includes multiple pairs of first channels and second channels.

27. The pasteurization system of claim 1, wherein a first channel is adjacent to and receives heat from multiple second channels.

28. The pasteurization system of claim 1, wherein a second channel is adjacent to and transfers heat to multiple first channels.

29. The pasteurization system of claim 1, wherein the first channel and the second channel each have a plate-like layout in which the width of the channel is much greater than the thickness of the channel.

30. The pasteurization system of claim 1, wherein there are multiple first channels and second channels and the first channels alternate with the second channels in a side-to-side relationship.

31. The pasteurization system of claim 1, further comprising support elements within at least one of the first channels and the second channels.

32-40. -40. (canceled)

41. A pasteurization system, comprising:

a liquid inlet configured to receive a liquid to be pasteurized;

a pump coupled to the liquid inlet for pressurizing the liquid;

a microchannel heat exchanger coupled to the liquid inlet and the pump, the microchannel heat exchanger having microchannels and configured to heat the liquid to a predetermined temperature for at least a predetermined time and configured to exchange heat between flows of liquid, the channels of the microchannel heat exchanger having a hydraulic diameter, expressed as four times the cross sectional area of the channel divided by the perimeter of the cross section, that is less than approximately one millimeter.

80. The pasteurization system of claim 41, wherein the heat exchanger is regenerative.

81. The pasteurization system of claim 41, wherein the liquid flows are counterflowing.

82. The pasteurization system of claim 41, wherein the heat exchanged is between different portions of the same liquid flow.

83. The pasteurization system of claim 41, further comprising a heater providing a heat input to the liquid flows.

42-79. -79. (canceled)

84. An ultra-high temperature milk pasteurization system, comprising:

a liquid inlet configured to receive milk to be pasteurized;

a pump coupled to the liquid inlet for pressurizing the liquid;

a counter flow heat exchanger coupled to the liquid inlet an configured to flow the milk through adjacent channels and the counterflow heat exchanger configured to heat the milk to a temperature of at least 135 degrees Celcius for at least a period of one tenth of a second.

122. The ultra-high temperature milk pasteurization system of claim 84, wherein the heat exchanger is regenerative.

123. The ultra-high temperature milk pasteurization system of claim 84, wherein the heat exchanged is between different portions of the same liquid flow.

124. The ultra-high temperature milk pasteurization system of claim 84, further comprising a heater providing a heat input to the liquid flows.

85-121. -121. (canceled)

125. A pasteurization system, comprising:

a liquid inlet configured to receive a liquid to be pasteurized;

a pump coupled to the liquid inlet for pressurizing the liquid; and

a counter flow heat exchanger coupled to the liquid inlet and the pump, the counterflow heat exchanger configured to heat the liquid to a predetermined temperature for at least a predetermined time and configured to exchange heat between a flow of liquid in a first direction in a first channel with the flow of liquid in a second direction opposite the first direction in a second channel, a heating section that heats the liquid flow in at least one of the first channel and the second channel.

126-164. -164. (canceled)

165. A pasteurization system, comprising:

a liquid inlet configured to receive a liquid to be pasteurized;

a pump coupled to the liquid inlet for pressurizing the liquid;

a microchannel heat exchanger coupled to the liquid inlet and the pump, the microchannel heat exchanger configured to heat the liquid to a predetermined temperature for at least a predetermined time and configured to exchange heat between flows of liquid, the channels of the microchannel heat exchanger configured to produce substantially laminar flow within the channels.

204. The pasteurization system of claim 165, wherein the heat exchanger is regenerative.

205. The pasteurization system of claim 165, wherein the liquid flows are counterflowing.

206. The pasteurization system of claim 165, wherein the heat exchanged is between different portions of the same liquid flow.

207. The pasteurization system of claim 165, further comprising a heater providing a heat input to the liquid flows.

166-203. -203. (canceled)