KRULDER, Aloisia Jacoba Petronella (Patrijslaan 15, XL Den Haag, NL-2566, NL)
KRULDER, Aloisia Jacoba Petronella (Patrijslaan 15, XL Den Haag, NL-2566, NL)
| Claims 1. Method for producing lump-shaped bodies, such as ice cubes, by freezing a liquid substance, comprising the following steps: - providing a mould (1 , 2) with at least a series of mould cavities (4) which are connected to one another, - filling the mould cavities (4) with the liquid substance, - providing an element (15) in the series of mould cavities (4), such as an elongate element, - reducing the temperature of the mould (1, 2) while forming a freeze front in the substance, behind which freeze front the substance has changed into the frozen state, characterized in that - moving back the element in the series of mould cavities (4) in such a manner that it is always situated in front of the freeze front, - supplying, via the element (15), a liquid substance to the series of mould cavities (4) while moving back the element (15). 2. Method according to Claim 1, comprising rotating the element (15) about the longitudinal axis. 3. Method according to one of the preceding claims, comprising keeping said element (15) in the still liquid substance while pulling back the element (15). 4. Method according to one of the preceding claims, comprising the following steps: - placing the series of mould cavities (4) vertically, - introducing the element (15) from the upper end of the series of mould cavities (4), - moving back the element (15) from the series of mould cavities (4) in an upward direction. 5. Method according to one of Claims 1-2, comprising the following steps: - placing the series of mould cavities (4) horizontally, - introducing the element (15) from one end of the series of mould cavities (4) or, - moving back the element (15) from the series of mould cavities (4) in a lateral direction. 6. Method according to one of the preceding claims, comprising the following steps: - providing a mould (1, 2) with outer surfaces (5) which are parallel to one another, - providing a freezing device with opposite cooling plates (7), - bringing the outer surfaces (5) of the mould (1, 2) into contact with the respective cooling plates (7). 7. Method according to one of the preceding claims, wherein air is supplied via the element (15). 8. Method according to one of the preceding claims, wherein pulses or vibrations are generated in the element (15). 9. Method according to one of the preceding claims, wherein the lump-shaped bodies are removed together with and in the mould (1 , 2). 10. Combination for carrying out the method according to one of the preceding claims, comprising a device with a frame provided with a freezing chamber and a manipulator (17), an element for supplying liquid (15) which is or can be connected to a liquid supply, such as an elongate liquid-supplying element in connection with the manipulator, and control means for controlling the manipulator for the purpose of displacing the liquid-supplying element, as well as a mould (1, 2) having at least a series of mould cavities (4) which are connected to each other, which mould (1, 2) can be accommodated in the freezing chamber, so that, in the state in which the mould (1, 2) is accommodated in the freezing chamber, the liquid-supplying element (15) can be introduced into and removed from the series of mould cavities (4) of the mould (1, 2). 11. Combination according to Claim 10, wherein the displacement means are configured for displacing the element (15) along the longitudinal axis. 12. Combination according to Claim 10 or 11, wherein the displacement means are configured for rotating the element (15) about the longitudinal axis. 13. Combination according to one of Claims 10-12, wherein liquid-dispensing means (21) are provided along the longitudinal direction of the liquid-supplying element (15). 14. Combination according to Claim 13, wherein the mutual distance between liquid-dispensing means (21) corresponds to the mutual distance between the mould cavities (4) from a series (3). 15. Combination according to one of Claims 10-14, wherein the liquid-supplying element (15) has at least one spray nozzle for spraying liquid. |
The invention relates to freezing a liquid substance for the purpose of obtaining frozen cubes or lumps, for example freezing water in order to produce ice cubes.
However, it is also conceivable to use liquid substances other than water, such as soups, sauces and the like. In addition, emulsion can be used as well. When producing such cubes or lumps, a mould can be used which has a series of mould cavities which are connected to one another. When the freezing has been effected, a series of
interconnected cubes are obtained from the mould. The connections between the cubes are such that the cubes can subsequently be readily separated from one another.
Dutch patent application 1,034,074 discloses such a method for producing lump- shaped bodies, such as ice cubes, by freezing a liquid substance, comprising the following steps:
- providing a mould with at least a series of mould cavities which are connected to one another,
- filling the mould cavities with the liquid substance,
- providing an element in the series of mould cavities, such as an elongate element,
- reducing the temperature of the mould while forming a freeze front in the substance, behind which freeze front the substance has changed into the frozen state.
The cubes are frozen in a mould consisting of two mould halves, each of which mould halves has a series of cavities which are arranged in pairs and delimit a mould cavity for an ice cube. By moving these mould halves apart, the mutually connected ice cubes are released from the mould. According to a variant of this known method, an elongate element may extend through the series of mould cavities. This elongate element remains in the mould while the substance is being frozen. When the mould is opened, a series of ice cubes are thus obtained through which the elongate element extends. The ultimately obtained loose ice cubes therefore have an open passage in the region where the elongate element was situated.
Ice cubes can be used for various purposes. One important area of application is the use of ice cubes in the hotel, restaurant and catering trade, where the ice cubes are added to drinks. In this connection, the appearance of the ice cubes is important for the quality which the consumer of the drink experiences. In this case, the clarity of the ice is of overriding importance. However, with the known methods of freezing water in connection with a mould with closed mould cavities, it is difficult to achieve the clear, inclusion free character of the ice.
It is therefore an object of the invention to provide a method which makes it possible to produce a frozen product of improved quality. This object is achieved by a method for producing lump-shaped bodies, such as ice cubes, by freezing a liquid substance, comprising the following steps:
- moving back the element in the series of mould cavities in such a manner that it is always situated in front of the freeze front,
- supplying, via the element, a liquid substance to the series of mould cavities while moving back the element.
According to a first possibility, the freezing of the liquid substance is effected by slowly moving back the element in the mould cavities which initially contain a still liquid substance. The effect thereof is that the liquid substance is moved or stirred, which has the advantageous effect that inclusions, such as air inclusions, can escape more readily from the substance. However, the movement occurring in the liquid substance is limited, so that the freezing process can still take place. In addition to moving back, the element can also carry out a rotating movement, although this is not always necessary in order to obtain a frozen product of the desired quality.
Preferably, the rotating movement is carried out in order to obtain for example clear ice cubes. Instead of, or in combination with the rotating movement, a gas such as air may be supplied via the element. Thus, the formation of ice around the inlet in the element is prevented. In this case, liquid, optionally together with a gas, such as air, can be supplied via the element. If desired, pulses or vibrations may be generated in the element. Such vibrations also promote the formation of clear ice, and can be combined with the supply of air, and/or the rotation of the element.
The mould in which the series of mould cavities is provided, has external surfaces, the temperature of which can be reduced in a suitable freezing device.
Preferably, a freezing device with cooled contact plates is used, against which contact plates the external surfaces of the mould can be placed. In this case, the method preferably comprises the step of freezing the substance from opposite longitudinal sides of the series of mould cavities. The element is situated at some distance between the longitudinal sides of the mould cavities, so that this element remains freely movable in that portion of the substance which is not yet frozen and is situated between the already frozen areas adjacent to the longitudinal sides.
The mould may initially be filled with the substance to be frozen. As the element is moved back through the substance, the level thereof is reduced. Therefore, the method comprises the step of supplying, via the element, liquid substance to the series of mould cavities while the element is being moved back.
The lump-shaped bodies can then be treated in various ways. According to a first possibility, they can be left in the mould and be presented in this manner. Alternatively, the lump-shaped bodies can obviously also be immediately removed from the mould.
The method preferably comprises the step of introducing the element until the free tip thereof is situated substantially near the other end of the series of mould cavities. The method can be carried out both according to a variant in which the series of mould cavities is oriented horizontally and/or vertically; but an oblique position of the series of mould cavities is also possible.
With the variant in which the mould cavities are oriented horizontally or obliquely at a slight angle, it is not readily possible to introduce the liquid to be frozen into the mould cavities beforehand due to the fact that the liquid may flow out of the mould cavities before the freezing process starts. In such cases, the liquid, according to a second possibility, is introduced into the mould cavities only or partly via the liquid- supplying element, so that the recently introduced liquid immediately freezes while the liquid-supplying element is being moved back without having the opportunity of flowing away.
The invention furthermore relates to equipment for carrying out the above- described method. This equipment comprises, in combination, a device having a frame provided with a freezing chamber and a manipulator, a liquid-supplying element which is or can be connected to a liquid supply, which liquid-supplying element is connected to the manipulator, and control means for controlling the manipulator for the purpose of displacing the liquid-supplying element, as well as a mould having at least a series of mould cavities which are connected to each other, which mould can be accommodated in the freezing chamber, so that, in the state in which the mould is accommodated in the freezing chamber, the liquid-supplying element can be introduced into and removed from the series of mould cavities of the mould. The manipulator can be configured in many different ways, for example in the form of a robot arm which is suspended from the frame of the device. However, simple lifting means, optionally together with a rotating element, may also be considered. In particular, displacement means are for displacing the element along the longitudinal axis.
The displacement means may be configured for displacing the element along the longitudinal axis. Furthermore, the displacement means may be configured for rotating the element about the longitudinal axis. According to a further variant, several liquid- dispensing means may be provided along the longitudinal direction of the liquid- supplying element. By means of such a liquid-supplying element, the mould cavities can be filled relatively quickly. In particular, it may be provided that the distance between the liquid-dispensing means corresponds to the distance of the mould cavities in a series to each other. Preferably, the liquid-supplying element has at least one spray nozzle for spraying liquid.
The invention will now be described with reference to an exemplary embodiment illustrated in the figures, in which:
Fig. 1 shows two mould halves with a portion of a freeze plate with mould halves in exploded view and with liquid-supplying element, in perspective;
Fig.2 shows a top view of pairs of assembled mould halves with freeze plates with the parts separated;
Fig. 3 shows a top view of pairs of assembled mould halves with the freeze plates in the closed state;
Fig.4 shows the freeze plates with an elongate element;
Fig. 5 shows a top view of the series of connected ice cubes;
Fig. 6 shows a side view of the series from Fig. 5.
The mould halves 1, 2 illustrated in Fig. 1 are arranged mirror-symmetrically with respect to one another and have, on the surfaces facing one another, adjacent series 3 which each comprise a number of mould cavities 4. The mould cavities 4 are separated from one another by transverse flanges 11 and upright flanges 12. Each of the transverse flanges has a semicircular recess 13 which together form the recesses 14, the meaning of which will be explained below.
The surfaces 5 of the mould halves which are turned away from one another are meant to contact the corresponding surfaces 6 of the freeze plates 7. These freeze plates 7 each have an edge 8, 9, inside which in each case two mould halves 1, 2 can be accommodated, as is illustrated in the view from Fig. 2. On the other side with respect to the edges 8, 9, each freeze plate 7 has a small edge 10 which adjoins the edges 8, 9 of a neighbouring freeze plate 7, as can be seen in the view from Fig. 3 in which the various freeze plates 7 have been placed against one another.
Fig. 1 also shows a liquid-supplying element 15 which has several dispensing means 21, such as spray nozzles, arranged at a regular distance apart in the longitudinal direction thereof for supplying liquid to the mould cavities. Preferably, the mutual distance between these dispensing means is equal to the mutual distance between the mould cavities.
If the series of mould cavities 4 are oriented vertically or obliquely, they can be filled with a liquid, such as water, in the position illustrated in Fig. 3, which is possible via the circular recesses 14. Then, the elongate liquid-supplying element 15 is introduced into the series of mould cavities 4 via said circular recesses 14. The freeze plates 7 are brought to below freezing, to the desired freezing temperature, by the cooling ducts 18 in a known manner. The substance in the mould cavities 4 then begins to freeze from the opposite surfaces 5 thereof, in which case an inner region of the substance, in which the elongate liquid-supplying element 15 is situated, initially remains liquid. In this case, the largest part of the liquid does not have to be introduced via the liquid-supplying element 15. Only the amount of liquid which is required to keep the level in the series of mould cavities constant when the liquid-supplying element is being pulled back then has to be supplied via the liquid-supplying element.
While the substance is in the process of freezing, the elongate liquid-supplying element 15 is pulled back, namely in such a manner that it does not become blocked by freezing. As a result of this movement of the elongate liquid-supplying element 15, the substance continues to move slightly, due to which impurities, such as air inclusions, can escape more readily. In the case of freezing water, clear ice cubes are consequently obtained.
The elongate liquid-supplying element 15 can in this case also be rotated. The movements of pulling back and rotating the elongate liquid-supplying element 15 are made possible, for example by the robot arm 17, which is suspended from the frame 16 of the device. In addition, this robot arm 17 also carries a supply line 19, for the purpose of adding liquid substance from the supply container 20 to the series of mould cavities 4 when moving back the elongate liquid-supplying element 15.
In the above-described operation of the device, the liquid to be frozen is introduced into the mould cavities beforehand, except for the amount of liquid which is replenished to compensate for the withdrawal of the liquid-supplying element 15. However, it is not necessary to introduce liquid beforehand. It is also possible to introduce the liquid completely or partly via the liquid-supplying element 15. The liquid can then freeze immediately after it has been introduced into the cooled mould cavities. The advantage of this method is that the series of mould cavities can then also extend in the horizontal position, while nevertheless preventing liquid which has been introduced from flowing away since it freezes immediately.
According to a preferred embodiment, several liquid-dispensing means 21, such as spray nozzles, may be provided along the longitudinal direction of the liquid- supplying element. This makes it possible to carry out filling of the mould cavities quickly.
Gas, such as air, can also be supplied via the elongate element in order to improve the clarity of the ice obtained. This gas may optionally be supplied in combination with a liquid, such as water.