Medical contact shock freezer

Abstract

A medical contact shock freezer (10) adapted for fast freezing a plurality of individual bags (41-43, 51-53) containing a medical liquid, the individual bags being arranged side by side, adjacent to each other, in which the contact shock freezer comprises a pair of freezing plates comprising an upper freezing plate (21) and a lower freezing plate (22), at least one of the upper and lower freezing plates of the pair being moveable to define i) a loading position in which sufficient separation is provided between the freezing plates to load or unload the individual bags between the freezing plates and ii) a freezing position in which each individual bag is in contact with and is clamped between a contact surface of the upper freezing plate and a contact surface of the lower freezing plate; and in which, in its freezing position, the contact surface of the upper freezing plate is arranged at an angle of at least 2° to the horizontal.

Claims

1. A medical contact shock freezer adapted for freezing a plurality of individual bags arranged side by side, adjacent to each other and containing a medical liquid, wherein the contact shock freezer comprises: a pair of freezing plates configured to operate at a temperature which is equal to or less than −40° C. the pair of freezing plates comprising an upper freezing plate and a lower freezing plate, at least one of the upper and lower freezing plates of the pair of freezing plates being moveable to define i) a loading position in which sufficient separation is provided between the freezing plates to load or unload the individual bags containing the medical liquid and ii) a freezing position in which each individual bag containing the medical liquid is in contact with and is clamped between a contact surface of the upper freezing plate and a contact surface of the lower freezing plate in such a way that surfaces of the bags containing the medical liquid that are in contact with the freezing plates are flattened so as to increase a contact area and improve heat transfer; and wherein, in the freezing position, the contact surface of the upper freezing plate is arranged at an angle which is at equal to or more than 2° to a horizontal and equal to or less than 30° to the horizontal.

2. The medical contact shock freezer of claim 1, wherein, the shock freezer comprises a first pair of the upper and the lower freezing plates and a second pair of the upper and the lower freezing plates, the first pair of the upper and the lower freezing plates being arranged above the second pair of the upper and the lower freezing plates; wherein the first pair of the upper and the lower freezing plates comprises an immobile lower freezing plate and a moveable upper freezing plate; wherein the second pair of upper and lower freezing plates comprises an immobile upper freezing plate and a moveable lower freezing plate; and wherein, in the freezing position, the contact surface of each of the upper freezing plates is arranged at an angle which is at equal to or more than 2° to the horizontal and equal to or less than 30° to the horizontal.

3. The medical contact shock freezer of claim 2, wherein, the lower freezing plate of the first pair of upper and lower freezing plates and the upper freezing plate of the second pair of freezing plates are provided by a single, integrated freezing plate.

4. The medical contact shock freezer of claim 1, wherein, in the freezing position, the contact surface of the upper freezing plate is arranged at an angle of between 3° and 10° to the horizontal.

5. The medical contact shock freezer of claim 4, wherein, in the freezing position, the contact surface of the lower freezing plate is arranged at an angle of between 3° and 10° to the horizontal.

6. The medical contact shock freezer of claim 1, wherein, the contact surface of the upper freezing plate and the contact surface of the lower freezing plate are each planar contact surfaces.

7. The medical contact shock freezer of claim 1, wherein, in the freezing position, the contact surface of the upper freezing plate and the contact surface of the lower freezing plate are parallel.

8. The medical contact shock freezer of claim 5, wherein, in the freezing position, the contact surface of the upper freezing plate and the contact surface of the lower freezing plate are parallel.

9. The medical contact shock freezer of claim 1, wherein, movement between the loading position and the freezing position consists of a linear, vertical displacement of at least one of the freezing plates.

10. The medical contact shock freezer of claim 1, wherein, in the freezing position, the contact surface of the upper freezing plate and the contact surface of the lower freezing plate are each arranged at an angle of about 5° to the horizontal.

11. A blood plasma contact shock freezer configured for freezing a plurality of individual bags arranged side by side, adjacent to each other and containing liquid blood plasma, wherein the contact shock freezer comprises: a pair of freezing plates comprising an upper freezing plate and a lower freezing plate, at least one of the upper and lower freezing plates of the pair of freezing plates being moveable to define i) a loading position in which sufficient separation is provided between the freezing plates to load or unload the individual bags containing the liquid blood plasma and ii) a freezing position in which each individual bag containing the liquid blood plasma is in contact with and is clamped between a contact surface of the upper freezing plate and a contact surface of the lower freezing plate in such a way that surfaces of the bags containing the liquid blood plasma that are in contact with the freezing plates are flattened so as to increase a contact area and improve heat transfer; and wherein, in the freezing position, the contact surfaces of the upper freezing plate and the lower freezing plate are parallel and are each arranged at an angle of between 3° and 10° to the horizontal.

12. A method of shock freezing a plurality of individual bags containing a medical liquid, the method comprising: arranging the individual bags containing the medical liquid side by side, adjacent to each other between an upper freezing plate and a lower freezing plate of a contact shock freezer with the upper and lower freezing plates arranged in a bag loading position; subsequently closing the freezing plates to a freezing position by moving at least one of the upper and lower freezing plates to clamp each individual bag containing the medical liquid in contact with a contact surface of the upper freezing plate and a contact surface of the lower freezing plate with each individual bag containing the medical liquid being held in an angled bag configuration at an angle which is equal to or more than 2° to the horizontal and equal to or less than 30° to the horizontal; subsequently freezing the medical liquid in each individual bag to a temperature of equal to or less than −20° C. through heat exchange between the medical liquid and the upper and lower freezing plates; subsequently moving at least one of the upper and lower freezing plates to the loading position; removing the frozen bags containing a frozen medical liquid from the shock freezer.

13. The method of claim 12, wherein, each individual bag containing the medical liquid is held in an angled bag configuration at an angle of between 3° and 10° to the horizontal.

14. The method of claim 12, wherein, each individual bag containing the medical liquid is held in an angled bag configuration due to angling of the contact surfaces of the upper and lower freezing plates.

15. The method of claim 12, wherein, each bag holds the medical liquid selected from blood plasma, a biological preparation and a pharmaceutical preparation.

16. The method of claim 12, wherein, freezing the medical liquid in each individual bag comprises freezing each bag from a temperature of between 15° C. and 25° C. to a temperature of equal to or less than −25° C.

17. The method of claim 16, wherein, the freezing from temperature of between 15° C. and 25° C. to a temperature of equal to or less than −25° C. is accomplished in a freezing time equal to or less than 60 minutes.

18. The method of claim 12, wherein, the individual bags are selected from i) bags containing between 150 ml and 450 ml of blood plasma and ii) bags containing between 750 ml and 950 ml of blood plasma.

19. The method of claim 12, wherein, closing the freezing plates to the freezing position by moving at least one of the upper and lower freezing plates to clamp each individual bag containing the medical liquid in contact with the contact surface of the upper freezing plate and a contact surface of the lower freezing plate consists of displacing at least one of the freezing plates linearly and vertically.

20. The medical contact shock freezer of claim 1, wherein, one of the upper and lower freezing plates of the pair of freezing plates is a fixed freezing plate which is fixed and does not move; and the other one of the upper and lower freezing plates of the pair of freezing plates is a moveable freezing plate which is moveable to define i) the loading position in which sufficient separation is provided between the freezing plates to load or unload the individual bags containing the medical liquid and ii) the freezing position in which each individual bag containing the medical liquid is in contact with and is clamped between the contact surface of the upper freezing plate and the contact surface of the lower freezing plate in such a way that the surfaces of the bags containing the medical liquid in contact with the freezing plates are flattened so as to increase the contact area and improve heat transfer.

Description

(1) An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, of which:

(2) FIG. 1 is schematic front view of a shock freezer with its freezing plates in their loading position;

(3) FIG. 2 is a schematic front view of the shock freezer with its freezing plates in their freezing position; and

(4) FIG. 3 is a schematic side view of the freezing plates in their freezing position.

(5) The illustrated contact shock freezer 10 comprises: a first pair 11 of upper 21 and lower 22 freezing plates; and a second pair 12 of upper 31 and lower 32 freezing plates; the first pair 11 being arranged above the second pair 12. The lower freezing plate 22 of the first pair of freezing plates 11 and the upper freezing plate 31 of the second pair of freezing plates 12 are provided by a single, immobile, integrated freezing plate 13.

(6) In use, with each pair 11, 12 of freezing plates in its loading position (FIG. 1), a first series of plasma bags to be frozen is arranged in rows (the front bag 41, 42, 43 of each row being illustrated in FIG. 1) between the upper 21 and lower 22 freezing plates of the first pair of freezing plates 11 by being placed on an operating surface provided by the lower freezing plate 22 by an operator standing in front of the freezer 10. A second series of plasma bags to be frozen is similarly arranged in rows (the front bag 51, 52, 53 of each row being illustrated in FIG. 1) between the upper 31 and lower 32 freezing plates of the second pair of freezing plates 12 by being placed on an operating surface provided the lower freezing plate 32 by an operator standing in front of the freezer 10. Each pair 11,12 of freezing plates is then moved from its loading position (FIG. 1) to its freezing position (FIG. 2) in the following way: the upper freezing plate 21 of the first pair of freezing plates 11 is moved vertically downwards by a pair of vertically arranged hydraulic cylinders 61, 62 arranged at the left side 61 and right side 62 of the upper freezing plate to clamp the first series of plasma bags to be frozen between a contact surface 23 of the upper freezing plate 21 and a contact surface 24 of the lower freezing plate 22; and the lower freezing plate 32 of the second pair 12 of freezing plates is moved vertically upwards by a pair of vertically arranged hydraulic cylinders 63, 64 arranged at the left side 63 and right side 64 of the lower freezing plate 32 to clamp the second series of plasma bags to be frozen between a contact surface 33 of the upper freezing plate 31 and a contact surface 34 of the lower freezing plate 32. In the freezing position (FIG. 2), with the plasma bags 41, 42, 43, 51, 52, 53 clamped between their respective freezing plates, the plasma in the bags is frozen from a temperature of about 20° C. to a temperature of −30° C. in a time of about 40 minutes. Once the plasma bags have been frozen, each pair of freezing plates 11, 12 is moved from its freezing position (FIG. 2) to its loading position (FIG. 1) and the plasma bags are removed by an operator standing at the front of the shock freezer 10 and placed in cold storage.

(7) The illustrated contact shock freezer 10 is shown schematically with nine plasma bags arranged between each pair 11, 12 of freezing plates. The first pair 11 of freezing plates 11 has three lines of plasma bags arranged across its width (of which the front bag 41, 42, 43 of each line is illustrated in FIG. 1 and FIG. 2) and three lines of plasma bags arranged across its depth (of which the left side bag 41, 44, 47 of each row is illustrated in FIG. 3). The illustrated arrangement for the second pair 12 of freezing plates is similar. Flattening and compression of the plasma bags in the freezing position is schematically illustrated in FIG. 2.

(8) Contact surfaces 23,24 of the first pair 11 of freezing plates 21, 22 are each planar and parallel to each other and are arranged to slope upwardly from the front 71 to the rear 72 of the shock freezer 10 at an angle α to the horizontal. Similarly, contact surfaces 33,34 of the second pair 12 of freezing plates 31, 32 are each planar and parallel to each other and are arranged to slope upwardly from the front 71 to the rear 72 of the shock freezer 10 at an angle α to the horizontal. The angle α is preferably between about 2° and about 10°, for example about 5° but has been shown in an exaggerated fashion in FIG. 3 for illustrative purposes.

(9) As shown in FIG. 3, each bag is held in an angled bag configuration at an angle α to the horizontal, that is to say, a plane passing centrally through each bag with respect to its upper and lower walls has an angle α to the horizontal.