NL2002074C - CHEESE PREPARATION DEVICE WITH A GUILLOTINE KNIFE FOR CUTTING WRONGEL BLOCKS. - Google Patents

Description

Title: Cheese-making device with a guillotine knife for cutting curd blocks.

The invention relates to a device for the preparation of cheese, comprising at least one device for receiving and compacting cheese curd provided with a guillotine knife with a cutting edge and a rear edge situated at the end remote from the cutting edge for cutting off curd blocks, wherein the guillotine knife can move back and forth between guide members and has an open position in which a curd block to be cut can pass through the guillotine knife, and a closed position, in which the guillotine knife has cut a curd block, means being provided for a cut curd block transversely to the cut. plane of the guillotine blade.

In the cheese production process, curd is prepared in a known manner from milk in a curd maker. The curd is usually stirred and sliced in the curd maker, and the whey released thereby is partly discharged and, for the rest, supplied together with the curd mass via a buffer tank to a device for producing blocks of cheese. Although cheese can be prepared in many ways from curd, large-scale cheese production often uses so-called draining or molding columns. Small-scale cheese production often uses so-called draining trays, also known as pre-pressing trays. Drain columns are used in processing the whey-curd mixture shortly after curd preparation. In the processing of pre-leavened curd, e.g. in the production of cheese of the Cheddar type, form columns are used in which pre-drained and soured curd is processed. Both types of columns comprise a hollow vertical tube, to which, in operation, a mixture of curd and whey is supplied at the top in the case of draining columns or the pre-drained and acidified curd in the case of molded columns. In the column, the curd is increasingly compacted from top to bottom, so that curd blocks can be cut at the bottom of the column. For this purpose a horizontal guillotine blade is placed on the underside of the column. The guillotine blade closes the column and supports the curd column in the closed position. The guillotine blade is periodically opened, allowing the curd column in the tube to move down an adjustable distance. For this purpose, a dosing plate which is vertically movable up and down in a sliding sleeve or dosing chamber (in the case of form columns) is present, which dosing plate is placed under the guillotine knife. The dosing plate is brought to just below the guillotine knife prior to opening the guillotine knife and takes over the support of the curd column when the guillotine knife is opened. Subsequently, the dosing plate is lowered over an adjustable distance, which corresponds to the desired height of the curd block. Subsequently, when the guillotine knife is returned to the closing position, a curd block is cut off from the curd column and the knife takes over the supporting function of the curd column again from the dosing plate.

The cut curd block now lies on the dosing plate in the sliding sleeve or dosing chamber. The dosing plate is then lowered further until the curd block is located at the bottom of the sliding sleeve or dosing chamber. Then with draining columns the sliding sleeve with the curd block therein is shifted sideways to above a cheese mold and transferred to the cheese mold. In the case of molded columns, only the cut-off curd block is slid sideways through one of the side walls via a side wall that can be folded away or removable and is moved externally to a filling installation.

It is noted that in a so-called single draining column, a single curd block is cut off each time. With a multiple draining column, there are several vertical curd receiving tubes present in the draining column and, in operation, several curd blocks are also cut off simultaneously by the guillotine knife. These are captured in a sliding bus with several recording spaces, also called cassette.

In a draining pan, a curd bed is formed in a horizontal rectangular vessel by distributing the whey and curd mixture on a perforated bottom, for example by using a mat, wherein one or more side walls can also be perforated depending on the embodiment. The curd bed is drained via the perforated bottom 10 thus draining the whey and the drained curd bed is subsequently mechanically pre-pressed, for example by applying compressive force to the top of the curd bed with for instance compressed air driven pressing plate or pressing plates. The curd bed is subsequently made horizontally via one of the sides of the drain pan 15 to the cheese molds, wherein the curd bed is cut into curd blocks using at least one vertically operating guillotine knife. The cut curd blocks are thereby separated from the curd bed or separated from each other by a guillotine knife and discharged transversely to the plane of the guillotine knife.

For the sake of simplicity the following is based on a device with a single drainage column, such as, for example, the Tetra Tebel Casomatic® SC marketed by the applicant. However, the invention also applies to a device with a multiple drainage column, such as, for example, the Tetra Tebel Casomatic® MC marketed by the applicant.

The invention also applies to a molding column, such as, for example, the Tetra Tebel Blockformer® marketed by the applicant.

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Furthermore, the invention applies to a drainage vessel, such as, for example, the Tetra Tebel Pressvatic® marketed by the applicant.

In the situation in which the guillotine knife is in the closed position after cutting a curd block, and the dosing plate then starts to move downwards, the cut curd block must separate from the underside of the guillotine knife. It has been found that defects can occur in the curd block in that the curd block sticks to the guillotine knife. The curd block, as it were, sucks on the bottom surface of the guillotine knife and between the guide of the guillotine knife.

Under the influence of the curd block's own weight, however, the curd block subsequently comes off the guillotine knife rather abruptly. As a result of the forces occurring thereby, defects may arise in the curd block in the form of so-called edge openings, also called pinholes and in the form of breaking-up pieces of curd. With light curd blocks or curd blocks discharged sideways (with draining vessels) where the own weight does not reinforce the release, or insufficiently, the curd block wants to release the knife surface with difficulty. This often results in local deformations of the curd block. There are indications that pinholes are caused by deformation and damage to the curd block as a result of the underpressure that occurs when the curd block detaches itself from the guillotine knife.

The invention has for its object to prevent or at least reduce the occurrence of such defects, and more generally to provide a device which forms curd blocks with as few defects as possible.

It is noted that FR-A-1532252 (Alpma) describes a device for the preparation of cheese with a curd drainage column and a knife placed at the lower end of the column for cutting curd blocks. The knife of this known device is provided with a wavy profile at the cutting edge, the wave shape extending transversely to the plane of the knife. When such a knife is used, however, cheese blocks with a corrugated surface are obtained, which is a major drawback.

Moreover, the known knife is provided with an internal fluid channel extending behind the cutting edge, which is connected to the lower surface of the knife via transverse bores. In operation, fluid jets are directed via the fluid channel and the transverse bores to the surface of a cut curd block located under the knife. However, these fluid jets lead to damage to the vulnerable curd block.

According to the invention, a device of the type described above is characterized in that fluid supply channels are provided in the guillotine knife guide members and / or at least the rear edge of the guillotine knife for supplying a fluid to the interface between the guillotine knife and the guillotine blade surface of the cut curd block.

In the following, the invention is further described with reference to the accompanying drawing of some exemplary embodiments.

Figure 1 shows schematically an example of a known cheese-making device to which the invention can be applied; Fig. 2 schematically illustrates step-by-step the operation of a dosing device of a cheese-making device with vertical column; Figure 3 schematically shows an example of a guillotine knife according to the invention.

Figure 4 is a diagrammatic sectional view of an example of a dosing device of a cheese-making device with a vertical draining column; Figure 5 shows diagrammatically in longitudinal section an example of a part of the guide of a guillotine knife according to the invention;

Figure 1 shows schematically an example of a known cheese-making device 1, such as is marketed by applicant, for example, under the name Tetra Tebel Casomatic® SC, to which the invention can be applied. The device shown comprises a vertical tubular drainage column 2, which is provided with three drainage sections 3, 4 and 5, which are arranged in the vertical direction with mutual spacing. In operation, a curd mixture is supplied to the upper end 6 of the column 10, as is schematically indicated by an arrow 7. The drainage sections are each provided with a jacket 8, 9,10, which encloses a perforated wall portion 11, 12,13 of the drainage column. In operation, whey emerging from the whey curd mixture is collected in the jackets and discharged in a known manner by means of whey discharge pipes 14 to 17 provided with control valves V to a whey reservoir 18.

It is noted that the device shown comprises a single column, but that the invention is also applicable to cheese-making devices with a multi-column, such as, for example, being marketed under the name Tetra Tebel Casomatic® MC. A multiple column comprises a number of parallel vertical drainage pipes which are placed within a common outer casing. Individual drainage sections are formed by horizontal partitions or the like arranged in the casing, which have passage openings for the drainage pipes but are furthermore closed partitions.

The drainage column 2 of the single type, or of the multiple type (not shown), connects with its underside to a dosing device 19 for cutting and discharging curd blocks. The curd column located in operation in the drainage column rests on a horizontal guillotine blade 20 which closes off the underside of the drainage column and which can be operated by a cylinder 21 or otherwise, such as 7 symbolized with a double arrow P1. The guillotine knife is a plate-shaped knife with an opening for passage of the curd column in the open position of the knife. An example is shown in Figure 3. A guide of the guillotine knife is shown schematically at 30.

Below the guillotine blade 20 and the guide 30 there is a sliding sleeve 22, with a dosing plate 23 which in fact forms an up and down movable bottom of the sliding sleeve, which is movable in the vertical direction by means of a vertical dosing plate lifting device, in the Next further represented as a cylinder 24, as indicated by an arrow P2. The dosing plate lifting device can, however, also be provided with, for example, electric drive means, such as a stepper motor or servo motor. The sliding sleeve can further be shifted in the horizontal direction by means of a cylinder 25 or in another way, as indicated by a double arrow P3. The sliding sleeve can be pushed aside by the cylinder 25 to above so-called lock plates 26, 27. The sliding sleeve with a cut-out curd block therein shifts from the dosing plate 23 to the lock plates. Between the dosing plate 23 and the lock plates there are one or more transfer plates (not shown). When the lock plates are pushed apart, the curd block falls into a cheese mold 29 placed below the lock plates on a conveyor device 28. In Figure 1, a curd block WB is located in the cheese mold. It is noted that embodiments with only one lock plate or without lock plates are also possible.

The process described above is, insofar as it is important for the present invention, again shown schematically in greater detail in Figure 2. Figure 2 uses the same reference numerals for corresponding parts as in Figure 1. Figure 2 illustrates the cutting of a curd block and transferring it to a cheese mold for a single-column drainer. In the case of a multiple column, the sliding sleeve and the cheese molds are provided with an 8 number of receiving spaces corresponding to the number of drain pipes in the column.

Figure 2 shows a curd column W which is in operation in the drainage column not shown in Figure 2. In figure 2A the curd column W rests on a guillotine knife 20 which closes the drainage column at the bottom. In the situation of Fig. 2A, close to the guillotine blade 20 and the guide 30 of the guillotine blade, there is a dosing plate 23 in a sliding bush 22. The dosing plate 23 can be displaced vertically by cylinder 24. Furthermore, horizontally operating cylinders 21, 25 shown, which are coupled to the guillotine blade and the sliding sleeve.

In the situation of Fig. 2B, the guillotine knife 20 is opened and the curd column W rests on the dosing plate 23. The curd column is moved down the desired distance with the aid of the cylinder 24 and the gravity and is located with a lower part in the sliding sleeve 22. The guillotine knife is then closed again as shown in figure 2C, as a result of which a loose curd block WB is formed, which is located under the guillotine knife in the sliding bushing.

The dosing plate 23 is then moved downwards, so that the curd block WB comes to lie at the bottom of the sliding sleeve 22, as shown in figure 2D.

The sliding sleeve with the curd block is then shifted laterally in a known manner to above a cheese mold and the curd block is deposited in the cheese mold.

In the situation shown in Figure 2C, the upper surface of the curd block WB lies against the lower surface of the guillotine knife 20. The upper part of the curd block is also enclosed by the knife guide 30 of the guillotine knife. This knife guide has a round ring shape at a round drainage column, or has an angular ring shape according to the above curd column, or has multiple round or angular ring shapes according to the above multiple drainage columns or tubes and the opening formed by the knife guide has substantially the same dimensions as the opening in the guillotine knife. It is noted that where in the description and claims reference is made to ring shape or ring, both a circular or elliptical or similar shape and a circular angular shape are meant, whether or not with rounded or chamfered corners. An example of a guillotine knife 20 is shown schematically in Figure 3. The guillotine knife is plate-shaped with a closed part 31 and an opening 32 with a cutting edge 33. In the closed position of the guillotine knife the curd column rests on the closed part 31, 10 as 2A, 2C and 2D. In the open position of the guillotine knife, the curd column W sinks through the opening 32 of the guillotine knife and is collected by the up and down movable dosing plate 23. In Figure 2B, the guillotine knife is in the open position and the dosing plate has already been moved downwards. When the guillotine knife 15 is subsequently closed again, the cutting edge 33 cuts through the curd column, so that a curd block is formed.

During the further downward movement of the dosing plate, the cut curd block must be separated from the bottom surface of the closed part 31 of the guillotine knife. The curd block must thereby separate itself from the guillotine knife. As already indicated above, this can lead to undesired damage to the curd block and thus to the cheese ultimately obtained. Practice has shown that the curd block adheres, as it were, to the underside of the guillotine knife and that under the influence of its own weight and gravity and the tensile force, the downward moving dosing plate exerts via the adhesive force of the underside of the curd block , release in time. Depending on the above process, the curd block will still release from the knife after some time, which will then happen abruptly. As a result, sudden high air flows occur along the block to the gap forming between the block and the knife. These air flows 10 must thereby pass the blade guide. Vacuum suction can also cause whey currents in the curd block, which can also lead to structural damage to the block.

The invention is based on the idea that the release of a curd block from the underside of the guillotine knife can take place less abruptly and more flexibly if a suitable fluid is supplied to the interface between the lower surface of the guillotine knife and a curd block lying against that lower surface. The fluid should be a fluid that is harmless to the curd block, such as for example air or whey or other natural liquid, such as for example water, retentate, permeate and the like. Retentate and permeate are products that are obtained during membrane filtration of whey or milk.

An example of a method for supplying air to the interface between the bottom surface of a guillotine knife and the top surface of a curd block is illustrated in Figure 3.

The guillotine knife 20 shown in bottom view in Figure 3 is provided with shallow grooves 35 on the underside. The grooves are located on the rear edge of the knife remote from the opening 32 in the knife and extend from the rear edge of the knife in the direction of the opening 20 of the knife. The grooves are less deep than the thickness of the guillotine knife. In the example shown, grooves 35 have such a length that the closed end of the grooves in the closed position of the knife extends just beyond the knife guide 30 indicated by a broken line 36. The grooves thus bridge the knife guide on the rear side of the guillotine knife, whereby air can easily flow to the interface of the curd block and the underside of the guillotine knife and no longer has to flow up along the knife guide and the curd block with difficulty. Experiments have shown that as a result a curd block does indeed release more smoothly from the guillotine knife and that significantly less damage to the curd block occurs and significantly reduces the formation of pinholes. The inflowing air can be ambient air under atmospheric pressure.

As an alternative (not shown), the grooves can also be extended further to further above the curd block, whereby the contact surface between the curd block and the guillotine knife is reduced. The reduced contact area also reduces the adhesive power.

Figures 4 and 5 illustrate another exemplary embodiment of the invention, wherein via channels in the knife guide from a liquid source, a liquid which is harmless to a curd block is supplied to the interface between the underside of the guillotine knife and the upper side of the curd block.

Figure 4 shows diagrammatically in vertical section a part of a dosing device 19 of a cheese-making device according to the invention. The dosing device has a housing 40, containing a guillotine knife 20 with bent longitudinal edges, a sliding sleeve 22, a dosing plate 23 connected to a piston rod of dosing cylinder 24, not shown.

The guillotine blade can be seen in cross section, as well as upper longitudinal guide profiles 42 and lower longitudinal guide profiles 43 of the guillotine blade guide 30.

Furthermore, one of the upper transverse guide profiles 44 and one of the lower transverse guide profiles 45 can be seen. The transverse and longitudinal guide profiles in each case form a ring whose opening is in line with the curd column.

In the example shown, the two lower longitudinal guide profiles 43 are provided with channels 46, which extend in the longitudinal direction of the profiles and to which a fluid can be supplied.

Figure 5 shows schematically a longitudinal section of a profile provided with a fluid channel 46. This can be a lower longitudinal profile 43, but a transverse profile could also be provided with a robust channel 12. Fluid channels can be arranged in one or both transverse profiles and or in one or both longitudinal profiles.

The profile 43 shown in Figure 5 has a channel 46 open at the top, the bottom 47 of which in this example rises obliquely from a fluid supply end 46a with a relatively great depth to the top surface 48 of the guide profile. At the deep end 46a of the channel there is a longitudinal bore 49, which connects the channel 46 to an outer surface, in this example a head end surface 50, and which forms a connection for a fluid supply line.

The channel 46 lies in the central part of the profile, both in the longitudinal direction and in the (horizontal) transverse direction.

Furthermore, the top surface 48 of the guide profile at the location of the channel 46 in the inner edge, i.e. the edge facing the other longitudinal guide profile, is provided with a number of shallow recesses 51, via which a fluid present in the channel to the interface can flow between the guillotine knife and the upper part of a curd block enclosed by the lower guide profiles. The fluid can be air or another non-harmful gas, but also a suitable liquid, as indicated above. In the case of a liquid, the fluid supply line 52 indicated by a broken line can be provided with a controllable shut-off valve 53. In this way it is possible, if desired, to ensure that only with closed guillotine knife and a curd block located below it, which is still against the underside of the guillotine knife The fluid is supplied to the interface between the two so that the fluid fills the gap between the curd block and the guillotine knife and, as it were, also drives the curd block from the guillotine knife and thereby also forms a separation layer on the curd block.

It is noted that, after the foregoing, various modifications are obvious to those skilled in the art. A dosing device can thus have both a guillotine knife with grooves 35 and one or more lower guide profiles 13 with a fluid channel. If the rear guillotine blade is provided with grooves 35 as shown in figure 3 and also the transverse guide profile 30 (figure 3) lying in the closed position below the rear side is provided with a fluid channel 46 as shown in figure 5, the recesses 51 can be omitted.

It is also possible, for example, to first flow a small amount of whey or another suitable liquid to the interface between the curd block and the guillotine knife and then air. Suitable control means with, for example, controllable valves can be provided for this purpose. A liquid layer then forms between the curd block and the knife surface, as a result of which the air flowing in later does not have direct access to the top of the curd block. This action is performed until the curd block has been separated from the guillotine knife or for some time thereafter.

A guillotine blade could also be provided with shallow grooves in other places.

It is further noted that the use of fluid feed grooves in a guillotine knife is also applicable in other cheese-making devices, in which parts of a curd bed are cut off. An example is a machine of the Tetra Tebel Pressvatic® type in which a curd bed is transported in the horizontal direction and curd blocks are cut at the end of the machine with the aid of a vertical guillotine knife.

Furthermore, the invention is applicable to cheese-making devices 25 with vertical columns, independent of the cross-sectional shape of the columns.

These and similar modifications are understood to fall within the scope of the invention.

2002074

Claims (10)

CLAIMS 1. Device for the preparation of cheese, comprising at least one device for receiving and compacting cheese curd provided with a guillotine knife with a cutting edge and a rear edge situated at the end remote from the cutting edge for cutting curd blocks, wherein the guillotine knife can move back and forth between guide members and has an open position in which a curd block to be cut can pass through the guillotine knife, and a closed position, in which the guillotine knife has cut a curd block, means being provided for cutting a cut curd block transversely to the plane of the Displacing guillotine knife, characterized in that fluid supply channels are provided in the guillotine knife guide members and / or at least the rear edge of the guillotine knife for supplying a fluid to the interface between the guillotine knife and the surface of the cut off against the guillotine knife curd block. Device as claimed in claim 1, characterized in that the device for receiving and compacting cheese curd is of the type comprising a vertical curd column which in operation rests on a horizontally operating guillotine knife when it is in the closed position, the guillotine knife is at least provided with guide members lying beneath the guillotine knife and forming an annular structure with a passage opening corresponding to the cross-sectional shape of the vertical curd column, characterized in that the guillotine knife is provided along at least the rear edge with a number extending from the shallow grooves extending into the bottom surface of the guillotine blade, which, in the closed position of the guillotine blade, bridge the guide members at the location of said edge and which form fluid supply channels. 2002074 3. Device as claimed in claim 1, characterized in that the device for receiving and compacting cheese curd is of the type comprising a horizontal curd bed, which in operation is cut into curd blocks with a vertically operating guillotine knife, characterized in that: that the guillotine knife is provided at least at the rear edge with a number of shallow grooves extending transversely to the relevant edge in the knife surface lying on the side of the cut curd block, which grooves form fluid supply channels in the closed position of the guillotine knife. Device as claimed in claim 2, characterized in that the guillotine knife is a plate-shaped knife with an opening provided with a cutting edge and a closed part, wherein the grooves are situated on an edge remote from the opening. 5. Device as claimed in claim 2 or 4, characterized in that the guide members of the guillotine knife underneath the guillotine knife comprise longitudinal profiles and transverse profiles and that at least one of the longitudinal profiles and / or transverse profiles is provided with a channel open at the top, on either side bounded by longitudinal edges which lie against the guillotine blade and whose ends are spaced from the ends of the profile, the longitudinal edge of the channel lying on the inside of the annular structure being provided with shallow transverse grooves forming a fluid passage of the channel to the interface between the bottom of the guillotine knife and a cut curd block. Device as claimed in claim 5, characterized in that the channel from a deep end gradually becomes shallower to the other end of the channel, and in that the deep end is connected via a bore to a fluid supply line. 7. Device as claimed in claim 6, characterized in that the fluid supply line is provided with a controllable shut-off valve. Device as claimed in any of the foregoing claims 5, 6, 7, characterized in that the fluid supply channels are provided with control means for supplying a quantity of liquid followed by air to the interface. Device as claimed in any of the foregoing claims 5, 6, 7, 8, characterized in that at least a number of fluid supply channels is connected to a liquid source which provides a liquid that is harmless to a curd block. 10. Device as claimed in claim 9, characterized in that the liquid source provides a liquid from a collection comprising water, whey, retentate, permeate or another milk product. 2 0 0 2 fl 7 4