APPARATUS AND METHOD FOR DRAINING AND FORMING CURD

An apparatus for draining and forming curd is presented. The apparatus comprises multiple, vertically arranged towers, a common curd distribution arrangement for distributing a curd and whey mixture into the multiple towers and a drainage section for draining whey from the curd and whey mixture. The drainage section forms a continuous space that extends horizontally over each of the multiple towers, each of the multiple towers having openings into the space formed by the drainage section for allowing whey to pass from the multiple towers and into the drainage section. A base unit beneath the multiple towers receives drained curd from the multiple towers and place the drained curd in moulds.

TECHNICAL FIELD

The invention relates to cheese production in general, and more particularly to draining and forming curd.

BACKGROUND ART

Today there are different technologies available for removing whey from a curd and whey mixture such that drained curd is obtained. One such technology is to use a vertical tower, also referred to as continuous drainage tower or column. In addition to remove whey from the curd and whey mixture, the drained curd fed out from the vertical tower can be formed into curd blocks that can be placed in moulds and transferred to a final processing station. The combination of draining and forming curd in one and the same equipment as well as the possibility to operate continuously has made vertical towers a widely used piece of equipment in cheese production, such as in semi-hard cheese production. One such example is the Tetra Pak® Casomatic system marketed and sold by Tetra Pak.

Even though the vertical tower is a well-known piece of equipment within the field of cheese production, there is room for improvement. For instance, to even further reduce losses related to inconsistent product quality, it is requested by cheese producers to have cheese towers that to an even higher degree deliver consistent curd quality. Further, shortened production time is often requested by the cheese producers.

This may for instance by achieved directly by having more efficient draining and forming, but also indirectly in that the curd quality is more consistent and thus resulting in fewer production stops. Another need in the industry is to offer cheese production equipment that takes less space.

Based on the above, there is a need for improved vertical towers that can deliver even higher curd quality consistency and also improved cost efficiency.

SUMMARY

It is an object of the invention to at least partly overcome one or more of the above-identified limitations of the prior art. In particular, it is an object to provide an apparatus for draining and forming curd that can deliver improved curd consistency.

The object is generally achieved in that the apparatus comprises several towers linked to each other by one or several drainage sections such that the whey is allowed to be drained under mote similar circumstances. This may more efficiently balance out deviations in whey-to-curd ratios in the different towers, and thereby achieve a more consistent curd quality compared to when the different towers drain the curd and whey mixture in isolation, as is the case today.

According to a first aspect it is provided an apparatus for draining and forming curd, comprising multiple, vertically arranged towers, a common curd distribution arrangement for distributing a curd and whey mixture into the multiple towers, a drainage section for draining whey from the curd and whey mixture, the drainage section forming a continuous space that extends horizontally over each of the multiple towers, each of the multiple towers having openings into the space formed by the drainage section for allowing whey to pass from the multiple towers and into the drainage section, and a base unit arranged beneath the multiple towers to receive drained curd from the multiple towers and place the drained curd in moulds.

An advantage is that by having a common curd distribution arrangement as well as a drainage that extends over each of the towers, the whey can be more uniformly distributed and drained, making it possible to avoid deviations in curd-whey-ratio in the different towers. Having this possibility provides for that a more consistent curd quality can be obtained from the apparatus. An alternative or additional advantage is that more compact equipment can be realized due to the common curd distribution arrangement and by having one drainage section that extends over each of the towers.

The drainage section may be a first drainage section, and the curd drainage apparatus may comprise a second drainage section that is arranged vertically below the first drainage section for draining whey from the curd and whey mixture, the second drainage section forming a continuous space that extends horizontally over each of the multiple towers, each of the multiple towers having openings into the space formed by the second drainage section for allowing whey to pass from the multiple towers and into the second drainage section.

An advantage with having drainage sections at different heights is that the drainage of whey can be controlled with improved accuracy. Since a pressure formed by the curd and whey mixture at the second drainage section will be higher than a pressure formed by the curd and whey mixture and the first drainage section, placed above the second drainage section, different pressures can be applied for releasing the whey from the curd and whey mixture.

The curd drainage apparatus may further comprise a whey extraction pipe arrangement connected to each of the first and second drainage sections.

One advantage with having this pipe arrangement is that the apparatus can be made even more compact.

The apparatus may further comprise a control valve arranged to regulate a flow of whey leaving the drainage section, and a control unit arranged to regulate the control valve based on a difference between the pressure of the whey in drainage section and the pressure of the curd and whey mixture inside at least one of the towers at the location of the tower where the drainage section surrounds the tower.

By having the control valve, it is possible to adjust this such that a desired pressure inside the towers can be achieved. Since the pressure affects the whey drainage, this provides additional possibilities for cheese producers to meet desired properties of the drained curd, and thus the properties of cheese made from the curd.

The apparatus may further comprise a whey circulation unit connected to the drainage section and arranged to circulate whey over the drainage section, to increase the flow of whey and thereby release drained curd in the drainage section. An advantage of having the circulation unit is that small curd particles entering the drainage section can be more easily flushed away.

The curd and whey mixture distribution arrangement may be an agitating device arranged vertically above the multiple towers to distribute the curd and whey mixture into each of the multiple towers. An advantage with this is that a more uniform whey-to-curd ratio can be achieved in the different towers.

A volume of the drainage section, including the total volume of the parts of the towers passing through the drainage section, may be less than 40% larger than said total volume of said parts of the towers. One advantage with this is that a more compact apparatus may be realized. Another advantage is that the response time for controlling the whey drainage may be shorter since the volume of whey in the drainage section is relatively small. The volume of the drainage section is typically the same as the continuous space formed by the drainage section, i.e. it includes everything inside the volume, including the volume that is taken up by the towers. The total volume of the parts of the towers passing through the drainage section is the same volume as the volume the towers occupy within the drainage section.

The draining section may comprise a cleaning-in-place nozzle. An advantage with having the cleaning-in-place nozzle is that efficient cleaning of the apparatus can be achieved.

The base unit may comprise vertically movable dosing devices arranged underneath each of the multiple towers for receiving the drained curd, and a cutting unit for cutting the drained curd received by the dosing devices into blocks, wherein the dosing devices are configured to individually control the amount of curd that is received and cut from the respective tower. An advantage with this is that the base unit can compensate for deviations in curd quality, i.e. curd-to-whey ratio, by adapting the dosing devices and the cutting unit. Thus, this further reduces the risk of inconsistent curd quality. The dosing devices may configured to individually control the amount of curd that is received and cut from the respective tower by having a curd receiving platform that is lowered down until the desired volume or weight of curd has left the respective tower, and then the curd is cut of and placed in moulds.

A distance between two consecutively placed towers of the multiple towers may be less than 0.3 m. An advantage of having the towers placed close to one another is that efficient horizontal whey exchange can be achieved.

According to a second aspect it is provided a method for draining and forming curd, said method comprising distributing a curd and whey mixture into multiple towers by using a common distribution arrangement and via a common inlet, draining whey from the curd and whey mixture in a drainage section, the drainage section forming a continuous space that extends horizontally over each of the multiple towers, each of the multiple towers having openings into the space formed by the drainage section for allowing the whey to pass from the multiple towers and into the drainage section, receiving drained curd from the multiple towers by a base unit, arranged beneath the multiple towers, and placing the drained curd in moulds.

The same features and advantages as presented in view of the first aspect may be implemented for and applies to this second aspect.

Still other objectives, features, aspects and advantages of the invention will appear from the following detailed description as well as from the drawings.

DETAILED DESCRIPTION

FIGS.1aand1bgenerally illustrate an apparatus100for draining and forming curd.FIG.1aillustrates a front view of the apparatus100andFIG.1billustrates a side view of the apparatus100.

A purpose of the apparatus100is to remove whey102from a curd and whey mixture104. To achieve this the apparatus100can comprise a number of towers108a-c. In the particular example illustrated inFIGS.1aand1b, three towers108a-care used, but fewer or more towers may also be used.

The curd and whey mixture104can be fed into a common inlet110of the apparatus100. As illustrated, this common inlet110may be placed in a top section of the apparatus100, on top of the towers108a-c. From the common inlet110, the curd and whey mixture can be fed down into the towers108a-c.

Each of the towers108a-ccan be provided with one or several drainage sections112a-carranged at different heights of the towers108a-c. In the example illustrated, three drainage sections112a-care provided. Each of the drainage sections112a-cform a continuous space113a-cthat can extend horizontally over each of the towers108a-c. Having the apparatus100arranged in this way allows for that the whey to be drained from the different towers108a-cat different heights of the towers108a-c.

A volume of the drainage section112a, including the total volume of the parts115of the towers108a,108b,108cpassing through the drainage section (112a), may be less than 40% larger than said total volume of said parts115of the towers108a,108b,108c.

Below the towers108a-c, a base unit114can be arranged. Since whey102has been removed from the curd and whey mixture104during the transfer down the towers108a-c, the curd and whey mixture104has been transformed into drained curd116.

The drained curd116can, due to a lower whey content, be placed in moulds118and thereafter be processed further, e.g. final pressing, brining and ripening.

To remove the whey102from the drainage sections112a-c, a whey extraction pipe arrangement119can be provided. As illustrated, the whey extraction pipe arrangement119can be connected to lower sections of the drainage sections112a-csuch that released whey102can be extracted from the drainage sections112a-cto the base unit114. The whey102is released from the curd and whey mixture104due to a pressure formed in the towers108a-cby the gravity. The pressure in the drainage sections112a-cmay also be controlled for obtaining the desired whey drainage. Then, increasing the pressure in the drainage sections112a-creduces the drainage, while decreasing the pressure in the drainage sections112a-cincreases the whey drainage.

The whey102extracted via the whey extraction pipe arrangement119can be used for flushing out curd remains, also referred to as curd particles120, in the base unit114. By using the whey102in this way, there is no need to add water or similar to provide for that there is no build-up of curd particles120in the base unit114. This in turn provides for that the whey102leaving the base unit114comprises the whey102released from the curd and whey mixture104via the drainage sections112a-cand the curd particles120flushed out from the base unit114. Avoiding adding water provides for a more cost efficient piece of equipment, but also in that less liquid needs to be removed from the whey102when, for example, this is later transformed into whey powder.

The common whey extraction pipe arrangement119can comprise a main pipe122and connection pipes124a-c. The connection pipes124a-ccan be connected to the drainage sections112a-csuch that flow paths FP are provided from the drainage sections112a-cto the main pipe122. The connection pipes124a-ccan be provided with control valves126a-c. Having the control valves126a-con the connection pipes124a-cprovides for that horizontal whey exchange HWE in the different drainage sections112a-ccan be controlled. For instance, in case the control valve126aof the first drainage section112ais closed, the whey102will be directed downwards to the second and third drainage section112b,112c, thereby affecting the horizontal whey exchange HWE in the second and third drainage section112b,112c. The amount of whey102, or more particularly a ratio between whey and curd, has namely an effect on the horizontal whey exchange HWE. To control the control valves126a-c, a control unit127can be used. This control unit127can be used for controlling the control valves126a-cindividually or in combination as explained above.

The towers108a-care provided with openings128such that the whey102can pass from the towers108a-cinto the continuous spaces113a-cwhile the curd116is kept inside the towers108a-cand fed downwards to the base unit114. The control unit127can control the draining of whey by regulating the valves126a-c. By opening a valve to let out more whey, draining is increased for the associated drainage section. This is because less whey in the draining section causes less “back pressure” on the curd and whey mixture in the towers.

As illustrated, in the base unit114, which may be shared by several towers108a-c, the drained curd116can be formed into curd blocks130and placed in the moulds118. After being placed in the moulds118, the curd blocks130can be transferred to a final pressing station (not illustrated).

To provide for that the curd and whey mixture104is distributed evenly in the different towers108a-c, that is, that a similar ratio of curd and whey is fed into the different towers108a-c, a common curd distribution arrangement132can be used. As illustrated, the common curd distribution arrangement132can be an agitating device, herein illustrated as a two axle provided agitating device, arranged to mix the curd and whey mixture104such that a similar ratio of curd and whey is provided in the different towers108a-c.

The drainage sections112a-ccan be provided with cleaning-in-place (CIP) nozzles134a-csuch that efficient cleaning can be provided.

The base unit114can be provided with vertically movable dosing devices136a,136b,136arranged underneath each of the multiple towers108a,108b,108cfor receiving the drained curd116. The dosing devices136a-ccan be individually controlled, which is advantageous since the moisture content may vary in the different towers108a-c. The controlling of the different dosing devices136a-cmay be made based on height and/or on weight. Once a height setpoint and/or a weight setpoint is reached, i.e. once the desired height and/or weight is achieved, a cutting unit138acan be used for cutting of the drained curd1126such that the curd block130is formed. As illustrated, the cutting unit138acan comprise an upper cutting element138aarranged for dividing the curd block130from the drained curd116fed out from the towers108a-c. A lower, vertically and horizontally movable element138bis arranged below the cutting unit138afor receiving the curd block130. The same element138bmay be used for accomplishing the above described dosing. Once cut-off from the drained curd116fed out from the towers108a-cand resting on the lower element138b, a pusher unit140may be used for pushing the curd block130into the mould118. The movable lower element138bmay be moved towards the mould118for assisting in placing the curd block130into the mould118. For illustrative purposes only one cutting unit138a, lower element138band pusher unit140are illustrated, but to provide for that the curd blocks130can be formed individually for the different towers108a-c, there can be one cutting unit, lower element and pusher unit140for each tower108a-c.

The horizontal whey exchange HWE may arise due to variations of curd and whey content in the different towers108a-c, e.g. a tower holding curd and whey mixture104with a higher content of whey102compared to the curd and whey mixture104held a neighboring tower. The difference in variations of curd and whey content in the different towers108a-cmay be decreased due the common drainage sections, as these provide the same level of whey in each drainage section. This result in a similar back pressure for each tower which allows the curd and whey in the different towers to balance out and approach each other, while still keeping the design of the apparatus100simple and efficient.

Circulation units142a-cmay be provided in the drainage sections112a-c. The circulation units142a-cmay be a pump arrangement arranged to create an increased circulation inside the drainage sections112a-c, by feeding whey out from the respective drainage section and back into the same drainage section. By having this active circulation any curd particles passing through the openings128in the towers, into the drainage section112a-c, may be efficiently flushed away.

FIG.2is flow chart illustrating a method200for draining and forming curd. In a first step202, the curd and whey mixture104can be received in the apparatus100via the common inlet110. As described above, the apparatus100can comprise multiple towers108a-c. In a second step204, the curd and whey mixture104can be distributed into the multiple towers108a-cby using the common distribution arrangement132. In a third step206, the whey102can be drained from the curd and whey mixture104, into the drainage section112a-c. As described above, the drainage section112a-ccan form the continuous space113a-cthat extends horizontally over each of the multiple towers108a-c. Each of the multiple towers108a-ccan have openings128into the space113a-cformed by the drainage section112a-cfor allowing the whey102to pass from the multiple towers108a-cinto the drainage section112a-c. In a fourth step208, the drained curd116from the multiple towers108a-ccan be received by the base unit114, arranged beneath the multiple towers108a-c. In a fifth step210, the drained curd116can be placed in the moulds118.

Optionally, in a sixth step212the whey102released from the curd and whey mixture104can fed out from the drainage section112a-cvia the common whey extraction pipe arrangement119to the base unit114. As described above, the common whey extraction pipe arrangement119may comprise the main pipe122and the connection pipes124a-cprovided with the control valves126a-c. The connection pipes124a-cmay provide the fluid path FP for the whey102from the drainage section112a-cto the main pipe122. In a seventh step214, the control valves126a-ccan be controlled individually such that the draining of whey from the multiple towers108a-ccan be adjusted.

From the description above follows that, although various embodiments of the invention have been described and shown, the invention is not restricted thereto, but may also be embodied in other ways within the scope of the subject-matter defined in the following claims.