WO2010041940A1

WO2010041940A1 - Cheese making apparatus with a guillotine blade for cutting off curd blocks

Info

Publication number: WO2010041940A1
Application number: PCT/NL2009/050603
Authority: WO
Inventors: Harrie Spijkerman; Sijmen Sipma
Original assignee: Tetra Laval Holdings & Finance S.A.
Priority date: 2008-10-08
Filing date: 2009-10-07
Publication date: 2010-04-15
Also published as: NL2002074C

Abstract

An apparatus for making cheese, comprising at least one apparatus for receiving and compacting cheese curd, provided with a guillotine blade (20) having a cutting edge (33) and a rear edge remote from the cutting edge, for cutting off curd blocks, wherein the guillotine blade can move back and forth between guide means and has an open position in which a curd block to be cut off can pass the guillotine blade, and a closed position, in which the guillotine blade has cut off a curd block, wherein means are provided for displacing a cut-off curd block transversely to the plane of the guillotine blade, wherein in the guide means for the guillotine blade and/or at least the rear edge of the guillotine blade fluid supply channels (35) are provided for supplying a fluid to the interface between the guillotine blade and the surface of the cut-off curd block abutting against the guillotine blade.

Description

Title: Cheese making apparatus with a guillotine blade for cutting off curd blocks.

The invention relates to an apparatus for making cheese, comprising at least one apparatus for receiving and compacting cheese curd, provided with a guillotine blade having a cutting edge and a rear edge situated at the end remote from the cutting edge, for cutting off curd blocks, wherein the guillotine blade can move back and forth between guide means and has an open position in which a curd block to be cut off can pass the guillotine blade, and a closed position, in which the guillotine blade has cut off a curd block, wherein means are provided for displacing a cut-off curd block transversely to the plane of the guillotine blade. In the cheese production process, in a known manner, curd is made from milk in a curd maker. Usually, the curd in the curd maker is stirred and cut and the whey thereby released is partly discharged and for the rest is supplied together with the curd mass via a buffer tank to an apparatus for producing blocks of cheese. Although cheese can be prepared from curd in many ways, in large-scale cheese production often use is made of so-called draining or forming columns. In smaller-scale cheese production often use is made of so-called draining vats, also called prepress vats. Draining columns are used in the processing of the whey-curd mixture shortly after curd making. In the processing of pre-acidified curd, e.g. in the production of Cheddar-type cheese, forming columns are used where pre-drained and acidified curd is processed. Both types of columns comprise a hollow vertical tube, to which, in operation, at the top a mixture of curd and whey is supplied in the case of draining columns or the pre-drained and acidified curd in the case of forming columns. In the column, the curd is increasingly compacted from the top down, so that at the bottom of the column curd blocks can be cut off. To this end, at the bottom of the column, a horizontally acting guillotine blade is placed. The guillotine blade closes off the column and in the closed position supports the curd column. The guillotine blade is periodically opened, so that the curd column in the tube can move down over a settable distance. To this end, a dosing plate configured for vertical reciprocation in a sliding sleeve or dosing chamber (in case of forming columns) is present, which is placed under the guillotine blade. Prior to opening of the guillotine blade the dosing plate is moved to a position just below the guillotine blade and then takes over the support of the curd column upon opening of the guillotine blade. Thereupon the dosing plate is moved down over a settable distance, which corresponds to the desired height of the curd block. When thereupon the guillotine blade is moved into the closing position again, a curd block is thereby cut off from the curd column and the blade takes over the supporting function of the curd columns from the dosing plate again. The cut-off curd block now lies on the dosing plate in the sliding sleeve or dosing chamber. The dosing plate is then moved further down until the curd block is at the bottom of the sliding sleeve or dosing chamber. Then, in the case of draining columns the sliding sleeve with the curd block therein is moved sideways to a position above a cheese mold and transferred into the cheese mold. In the case of forming columns, only the cut-off curd block is moved out sideways by one of the sidewalls via an opposite sidewall which can be swung clear or removed, and is externally moved to a filling installation.

It is noted that in a so-called single draining column, in each case a single curd block is cut off. In a multiple draining column, there are multiple vertical curd receiving tubes present in the draining column, and also, in operation, multiple curd blocks are cut off at the same time by the guillotine blade. These are received in a sliding sleeve having multiple receiving spaces, also called cassette.

In a draining tank, in a horizontal rectangular vat a curd bed is formed by distributing the whey and curd mixture on a perforated bottom, for instance by the use of a mat while, depending on the design, also one or more sidewalls may be of perforated design. The curd bed is drained via the perforated bottom, whereby the whey is thus discharged and the drained curd bed is then mechanically prepressed, for instance by application of pressing force Lo the top of the curd bed with press plaie or press plates for instance driven with compressed air. The curd bed is thereafter passed out horizontally via one of the sides of the draining vat to the cheese molds, whereby the curd bed is cut into curd blocks using at least one vertically acting guillotine blade. The cut-off curd blocks are thereby separated from the curd bed or separated from each other by a guillotine blade and discharged transversely to the plane of the guillotine blade.

In the following, for the sake of simplicity, the starting point is an apparatus having a single draining column, such as for instance the Tetra Tebel Casomatic^® SC marketed by applicant. However, the invention is also applicable to an apparatus with multiple draining column, such as for instance the Tetra Tebel Casomatic^® MC marketed by applicant.

The invention is also applicable to a forming column, such as for instance the Tetra Tebel Blockformer^® marketed by applicant.

Further, the invention is applicable to a draining vat, such as for instance the Tetra Tebel Pressvatic^® marketed by applicant.

In the situation where the guillotine blade after cutting off a curd block is in the closed position, and the dosing plate thereupon starts to move down, the cut-off curd block needs to detach from the underside of the guillotine blade. It has been found that defects on the curd block may then occur due to the curd block sticking to the guillotine blade. The curd block, as it were, clings by suction onto the undersurface of the guillotine blade and between the guide of the guillotine blade.

Under the influence of the curd block's own weight, however, the curd block thereupon detaches rather abruptly from the guillotine blade. Due to the forces then occurring, defects may arise in the curd block in the form of so-called edge openings, also called pinholes, and in the form of bits of curd breaking loose. With light curd blocks, or laterally discharged curd blocks (in case of draining vats), where the inherent weight enhances release insufficiently, if at all, the curd block tends to come off the blade surface only with difficulty. Often this results in local deformations of the curd block. There are indications that pinholes are formed through deformation and damage of the curd block resulting from the reduced pressure created when the curd block detaches from the guillotine blade. The object of the invention is to prevent or at least reduce the occurrence of such defects, and more generally to provide an apparatus that forms curd blocks with as few defects as possible.

It is noted that in FR-A-1532252 (Alpma) an apparatus for making cheese is described having a curd draining column and a blade placed at the lower end of the column for cutting off curd blocks. The blade of this known apparatus is provided at the cutting edge with a wavy profile, the wave form extending transversely to the plane of the blade. In the use of such a blade, however, cheese blocks having a corrugated surface are obtained, which is a major drawback. Moreover, the known blade is provided with an internal fluid channel extending behind the cutting edge, which via transverse bores is in communication with the bottom face of the blade. In operation, via the fluid channel and the transverse bores fluid jets are directed at the surface of a cut-off curd block situated under the blade. These fluid jets, however, lead to damage of the fragile curd block

According to the invention, an apparatus of the above-described type is characterized in that in the guide means for the guillotine blade and/or at least the rear edge of the guillotine blade fluid supply channels are provided for supplying a fluid to the interface between the guillotine blade and the surface of the cut-off curd block abutting against the guillotine blade. In the following, the invention will be further described with reference to the appended drawing of a few exemplary embodiments.

Fig. 1 schematically shows an example of a known cheese making apparatus where the invention can be applied; Fig. 2 schematically illustrates stepwise the operation of a dosing device of a cheese making apparatus with vertical column;

Fig. 3 schematically shows an example of a guillotine blade according to the invention;

Fig. 4 schematically shows in section an example of a dosing device of a cheese making apparatus with vertical draining column;

Fig. 5 schematically shows in longitudinal section an example of a part of the guide of a guillotine blade according to the invention.

Figure 1 schematically shows an example of a known cheese making apparatus 1, such as for instance marketed by applicant under the name of Tetra Tebel Casomatic^® SC, where the invention can be applied. The apparatus shown comprises a vertical tubular draining column 2, which is provided with three draining sections 3, 4, and 5, which are arranged with a mutual interspace in vertical direction. In operation, a curd mixture is supplied to the upper end 6 of the column, as schematically indicated with an arrow 7. The draining sections are each provided with a jacket 8, 9, 10, which encloses a perforated wall portion 11, 12, 13 of the draining column. Whey egressing from the whey -curd mixture is operatively collected in the jackets and in a known manner discharged to a whey reservoir 18 through whey discharge pipes 14 to 17 provided with regulating valves V. It is noted that the apparatus shown comprises a single column, but that the invention is also applicable with cheese making apparatuses having a multi column, such as for instance marketed under the name of Tetra Tebel Casomatic^® MC. A multi column comprises a number of parallel vertical draining tubes, which are placed within a common outer jacket. Separate draining sections are formed by horizontal partitions or the like, arranged in the jacket, which have passage openings for the draining tubes but are otherwise closed partitions.

The draining column 2 of the single type, or of the multiple type not shown, joins via its underside a dosing device 19 for cutting off and discharging curd blocks. The curd column opera tively situated in the draining column rests on a horizontal guillotine blade 20 closing off the open underside of the draining column, which can be operated by a cylinder 21 or in a different manner, as symbolized with a double arrow Pl. The guillotine blade is a plate-shaped blade with an opening to allow the curd column to pass in the open position of the blade. An example is shown in Fig. 3. A guide of the guillotine blade is schematically shown at 30.

Situated under the guillotine blade 20 and the guide 30 is a sliding sleeve 22, with a dosing plate 23 which in fact forms a reciprocable bottom of the sliding sleeve, which is movable in vertical direction with the aid of a vertical dosing plate lifting device, in the following further represented as a cylinder 24, as indicated with an arrow P2. However, the dosing plate lifting device may also be designed with, for instance, electric drive means, such as a stepping motor or servomotor. The sliding tube can furthermore be moved in horizontal direction with the aid of cylinder 25 or in a different manner, as indicated by a double-headed arrow P3. The sliding sleeve can be pushed sideways by the cylinder 25 to a position above so-called sluice plates 26, 27, whereby the sliding sleeve with a cut-off curd block therein slides off the dosing plate 23 to the sluice plates. Situated between the dosing plate 23 and the sluice plates are one or more transfer plates, not shown. When the sluice plates are moved apart, the curd block falls into a cheese mold 29 placed under the sluice plates on a conveying device 28. In Fig. 1 curd block WB is in the cheese mold. It is noted that designs with only one sluice plate or without sluice plates are also possible. The above-described process, to the extent relevant to the present invention, is once more shown schematically in more detail and stepwise in Fig. 2. In Fig. 2, corresponding parts are provided with the same reference numerals as in Fig. 1. Fig. 2 illustrates the cutting off of a curd block and the transfer thereof to a cheese mold for a draining apparatus with single column. In the case of a multi column, the sliding sleeve and the cheese molds are provided with a number of receiving spaces corresponding to the number of draining tubes in the column.

Fig. 2 shows a curd column W which, in operation, is situated in the draining column, not shown in Fig. 2. In Fig. 2A, the curd column W rests on a guillotine blade 20 which closes off the draining column at the lower end. In the situation of Fig. 2A, closely under the guillotine blade 20 and the guide 30 of the guillotine blade, a dosing plate 23 is situated in a sliding sleeve 22. The dosing plate 23 can be moved in a vertical sense by cylinder 24. Further, horizontally acting cylinders 21, 25 are shown, which are coupled with the guillotine blade and the sliding sleeve.

In the situation of Fig. 2B, the guillotine blade 20 is open and the curd column W rests on the dosing plate 23. The curd column has been moved down over the desired distance with the aid of the cylinder 24 and gravity, and has a lower portion situated in the sliding sleeve 22.

Thereupon, the guillotine blade is closed again, as shown in Fig. 2C, yielding a loose curd block WB which is situated under the guillotine blade, in the sliding sleeve.

After this, the dosing plate 23 is moved down, so that the curd block WB comes to lie at the bottom of the sliding sleeve 2, as shown in Fig. 2D.

After this, in a known manner, the sliding sleeve with the curd block is moved laterally to a position above a cheese mold, and the curd block is deposited in the cheese mold.

In the situation shown in Fig. 2C the top surface of the curd block WB abuts against the bottom surface of the guillotine blade 20. Also, the upper part of the curd block is enclosed by the blade guide 30 of the guillotine blade. This blade guide has a circular ring shape in case of a circular draining column, or has an angular ring shape in conformity with the curd column standing above it, or has multiple circular or angular ring shapes in conformity with the multiple drainage columns or tubes standing above it, and the opening formed by the blade guide has substantially the same dimensions as the opening in the guillotine blade. It is noted that where in the description and claims reference is made to ring shape or ring, this is understood to cover both a circumferential circular or elliptic or like shape and a circumferential angular shape, with or without rounded or beveled angles. An example of a guillotine blade 20 is schematically shown in Fig. 3. The guillotine blade is plate-shaped with a closed part 31 and an opening 32 with a cutting edge 33. In the closed position of the guillotine blade, the curd column rests on the closed part 31, as can be seen in Figs. 2A, 2C and 2D. In the open position of the guillotine blade, the curd column W is lowered through the opening 32 of the guillotine blade and is received by the reciprocable dosing plate 23. In Fig. 2B, the guillotine blade is in the open position and the dosing plate has already been moved down. When thereupon the guillotine blade is closed again, the cutting edge 33 cuts through the curd column, so that a curd block is formed.

Upon the further downward movement of the dosing plate, the cut-off curd block needs to be separated from the bottom surface of the closed part 31 of the guillotine blade. This requires the curd block to detach from the guillotine blade. As already indicated above, this can lead to undesired damage of the curd block and hence of the cheese eventually obtained. Practice has proven that the curd block, as it were, sticks to the bottom side of the guillotine blade and that, under the influence of its own weight and gravity and the pull force exerted by the downwardly moving dosing plate via the adhesive force of the bottom side of the curd block, it comes off with a delay in time. Depending on the above process, the curd block will detach from the blade after some time anyway, which then happens abruptly. This gives rise to sudden large air streams along the block towards the gap forming between the block and the blade. These air streams then need to pass the blade guide. Also, through vacuum suction, whey streams may be formed in the curd block, which can also lead to structural damages to the block.

The invention is based on the idea that the detachment of a curd block from the bottom side of the guillotine blade can take place less abruptly and more smoothly if a suitable fluid is supplied to the interface between the bottom surface of the guillotine blade and a curd block abutting against that bottom surface. The fluid should be a fluid that is non-noxious to the curd block, such as for instance air or whey or other natural liquid, such as for instance water, retentate, permeate and the like. Retentate and permeate are products which are obtained upon membrane filtration of whey or milk.

An example of a method of supplying air or, if desired, a different fluid to the interface between the bottom surface of a guillotine blade and the top surface of a curd block is illustrated in Fig. 3. The guillotine blade 20 shown in bottom view in Fig. 3 is provided at the bottom side with shallow grooves 35. The grooves are situated at the rear edge of the blade remote from the opening 32 in the blade, and extend from the rear edge of the blade in the direction of the opening of the blade. The grooves are less deep than the thickness of the guillotine blade. In the example shown, grooves 35 have a length such that the closed end of the grooves in the closed position of the blade extends just beyond the blade guide 30 at that location, indicated by a broken line 36. The grooves hence bridge the blade guide on the rear side of the guillotine blade, so that air can easily flow towards the interface of the curd block and the bottom side of the guillotine blade and no longer needs to flow up with difficulty along the blade guide and the curd block. Experiments have shown that in this way a curd block indeed detaches more smoothly from the guillotine blade and that this entails significantly fewer damages of the curd block and significantly reduces the formation of pinholes. The affluent air may be ambient air under atmospheric pressure.

As an alternative, not shown, the grooves may be extended further to a point further above the curd block, so that the contact surface between curd block and guillotine blade is reduced. As a result of the reduced contact surface, also the adhesive force is reduced. Figs. 4 and 5 illustrate another exemplary embodiment of the invention, in which, via channels in the blade guide, a preferably natural liquid, non-noxious to a curd block, is supplied from a liquid source to the interface between the bottom side of the guillotine blade and the top side of the curd block. Fig. 4 schematically shows in vertical cross section a part of a dosing device 19 of a cheese making apparatus according to the invention. The dosing device has a housing 40, having therein a guillotine blade 20 with bent longitudinal edges, a sliding sleeve 22, and a dosing plate 23 connected with a piston rod of dosing cylinder 24, not shown. The guillotine blade can be seen in cross section, as well as upper longitudinal guide sections 42 and lower longitudinal guide sections 43 of the guillotine blade guide 30.

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

In the example shown, the two lower longitudinal guide sections 43 are provided with channels 46, which extend in the longitudinal direction of the sections and to which a fluid can be supplied. Fig. 5 schematically shows a longitudinal section of a section provided with a fluid channel 46. This can be a lower longitudinal section 43, but also a transverse section could be provided with such a channel. Fluid channels may be provided in one or both transverse sections and/or in one or both longitudinal sections.

The section 43 shown in Fig. 5 has a channel 46, open at the top, of which, in this example, the bottom 47 slants upwards from a fluid supply end 46a of a relatively great depth to the top surface 48 of the guide section. Situated at the deep end 46a of the channel is a longitudinal bore 49, which connects the channel 46 with an outer surface, in this example and end surface 50, and which forms a connection for a fluid supply line. The channel 46 is situated in the central part of the section, both viewed in longitudinal direction and viewed in the (horizontal) transverse direction. Furthermore, adjacent the channel 46, the top surface 48 of the guide section, in the inner edge thereof, that is, the edge facing the other longitudinal guide section, is provided with a number of shallow recesses 51, via which a fluid present in the channel can flow to the interface between the guillotine blade and the upper part of a curd block enclosed by the lower guide sections. The fluid can be air or other non-noxious gas, but also a suitable liquid, as indicated hereinbefore. In the case of a liquid, the fluid supply line 52 indicated with a chain-dotted line may be provided with a controllable shut-off valve 53. In this way, if desired, it can be realized that only with the guillotine blade closed and a curd block situated thereunder which still abuts against the bottom side of the guillotine blade, fluid is supplied to the interface between the two, so that the fluid fills up the gap between curd block and guillotine blade and, as it were, also drives the curd block off the guillotine blade and at the same time forms a separating layer on the curd block. It is noted that after the foregoing, various modifications will readily occur to those skilled in the art. Thus, a dosing device may have both a guillotine blade with grooves 35 and one or more lower guide sections with a fluid channel. When the guillotine blade is provided with grooves 35 at the rear side, as shown in Fig. 3, and also the transverse guide section 30 (Fig. 3) situated under the rear side in the closed position is provided with a fluid channel 46 as shown in Fig. 5, the recesses 51 could be omitted.

It is also possible, for instance, first to allow a small amount of whey or other suitable liquid to flow to the interface between curd block and guillotine blade, and then air. For this purpose, suitable control means with, for instance, controllable valves may be provided. Between the curd block and the blade surface a liquid layer is then formed, so that the air flowing in later does not gain direct access to the top side of the curd block. This action is carried out until the curd block is separated from the guillotine blade or for some more time after that.

Also, a guillotine blade could be provided with shallow grooves at different places.

Furthermore, it is noted that the use of fluid supply grooves in a guillotine blade is also applicable in other cheese making apparatuses, 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 a horizontal direction and at the end of the machine curd blocks are cut off with the aid of a vertically acting guillotine blade.

Furthermore, the invention is applicable to cheese making apparatuses with vertical columns independently of the cross -sectional shape of the columns.

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

Claims

1. An apparatus for making cheese, comprising at least one apparatus for receiving and compacting cheese curd, provided with a guillotine blade having a cutting edge and a rear edge situated at the end remote from the cutting edge, for cutting off curd blocks, wherein the guillotine blade can move back and forth between guide means and has an open position in which a curd block to be cut off can pass the guillotine blade, and a closed position, in which the guillotine blade has cut off a curd block, wherein means are provided for displacing a cut-off curd block transversely to the plane of the guillotine blade, characterized in that in the guide means for the guillotine blade and/or at least the rear edge of the guillotine blade fluid supply channels are provided for supplying a fluid to the interface between the guillotine blade and the surface of the cut-off curd block abutting against the guillotine blade.

2. An apparatus according to claim 1, characterized in that the apparatus for receiving and compacting cheese curd is of the type that contains a vertical curd column, which in operation rests on a horizontally acting guillotine blade when this is in the closed position, wherein the guillotine blade is at least provided with guide means situated under the guillotine blade, which form a ring-shaped construction with a passage opening corresponding to the cross-sectional shape of the vertical curd column, characterized in that the guillotine blade is provided along at least the rear edge with a number of shallow grooves extending from the edge into the bottom surface of the guillotine blade, which in the closed position of the guillotine blade bridge the guide means at said edge and which form fluid supply channels.

3. An apparatus according to claim 1, characterized in that the apparatus for receiving and compacting cheese curd is of the type that contains a horizontal curd bed, which in operation is cut into curd blocks with a vertically acting guillotine blade, characterized in that the guillotine blade is provided at at least the rear edge with a number of shallow grooves, extending transversely to the respective edges, in the blade surface situated δ on the side of the cut-off curd block, which grooves in the closed position of the guillotine blade form fluid supply channels.

4. An apparatus according to claim 2, characterized in that the guillotine blade is a plate-shaped blade with an opening provided with a cutting edge and a closed part, wherein the grooves are situated at an edge0 remote from the opening.

5. An apparatus according to claim 2 or 4, characterized in that the guide means of the guillotine blade situated under the guillotine blade comprise longitudinal sections and transverse sections and that at least one of the longitudinal sections and/or transverse sections is provided with a5 channel open at the top, bounded on opposite sides by longitudinal edges which lie against the guillotine blade and of which the ends are at a distance from the ends of the section, wherein the longitudinal edge of the channel situated on the inside of the ring-shaped construction is provided with shallow transverse grooves, which form a fluid passage from the0 channel to the interface between the bottom side of the guillotine blade and a cut-off curd block.

6. An apparatus according to claim 5, characterized in that the channel gradually becomes shallower from a deep end towards the other end of the channel, and that the deep end is connected via a bore with a fluid supply5 pipe.

7. An apparatus according to claim 6, characterized in that the fluid supply pipe is provided with a controllable shut-off valve.

8. An apparatus according to any one of the preceding claims 5, 6, 7, characterized in that the fluid supply channels are provided with control0 means for supplying to the interface an amount of liquid followed by air.

9. An apparatus according to any one of the preceding claims 5, 6, 7, 8, characterized in that at least a number of fluid supply channels are connected with a liquid source, which provides a liquid non-noxious to a curd block.

10. An apparatus according to claim 9, characterized in that the liquid source provides a liquid from a set comprising water, whey, retentate, permeate or another split product of milk.