NZ272825A - Mixing salt with cheese curd: salt dispenser includes rotating wheel - Google Patents

Description

New Zealand Paient Spedficaiion for Paient Number £72825 Patents Form # 5 2,7 28^5 NEW ZEALAND Patents Act 1953 . 7, 'vi ^ COMPLETE SPECIFICATION TITLE: Cheese Making APPLICATION#: 272825 FILING DATE : 21 August 1995 We,: Innovative Engineering Limited Address: Albert Street, Carters Flat, Cambridge, New Zealand Nationality: New Zealand hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: PF05.JWP FEE CODE -1050 272 This invention relates to cheese making, in particular but not necessarily solely to methods and apparatus for the measurement and control of salt dispensing and the mixing of granular or milled cheese curd.

When making cheese the salt application rate should be proportional to the curd flow. 5 In most systems this is achieved by measuring the depth of curd passing a level measuring fork on a delivery belt and using that information to determine the curd flow. In more sophisticated apparatus the curd flow rate can be measured by weighing the curd on a belt feeding curd to the Salter. This practice has resulted in a 50% decrease in salt in moisture variation on washed, noncheddar cheeses. Another 10 alternative approach to improving the salt in moisture control with belt salting is to control the rate of curd being fed to the Salter, by controlling the curd pump out rate from the vats and/or the draining belt speed to provide a substantially constant curd feed to the cheddaring belts, the mill and the salter.

In handling salt curd mixing is very important. With smaller curd particles, which 15 absorb salt more readily, it becomes even more important. Most belt systems only have mixing in a vertical plane. Cheese plants, which weigh the curd almost always, use trommel mixers to improve product uniformity. Most belt salting systems have cross feed and mixing augers after salting and mellowing but prior to the blockforming step to improve product uniformity and to provide uniform feed to the 20 cheese block formers. The holding time from salt addition to block forming is commonly referred to as mellowing. Increasing this time increases salt retention requiring less salt to be used as well as increasing cheese moisture. 8811ics2.n96/CW/lv • 27 2 £ Two main methods are in use today for salt application and mixing of the salt into the mill or granular cheese and these are as follows. 1. Boom methods.

In these methods the curd flow rate is measured on the cheddaring belt by a 5 curd fork, the salt requirement is then calculated and delivered to the curd after milling by means of a salting boom which oscillates from side to sio°. of the curd conveying belt. The air conveyed salt is discharged through the hollow boom. The salt application rate is controlled by the conveyor speed. 2. Trommel The curd flow rate is usually calculated from a separate weigh belt, the salted and weighed curd are then dispensed into an open ended rotating drum and mixed in the trommel before discharging onto the mellowing belt. In general the salt application is controlled by a variable speed salt conveyor into an air conveying system or by an auger fed directly by a salt hopper.

Each of these methods have the disadvantage that there is a substantial lag between a variation in the curd supply rate occurring and the required change of the salt delivery.

It is therefore an object of the present invention to provide methods and apparatus which will obviate or minimise the foregoing disadvantages in a simple yet effective manner or which will at least provide the public with a useful choice. 8811ics2.n96/CW/iv 27 2 8 2 5 Accordingly in one aspect the invention consists of an apparatus for dispensing flowable materials comprising a hopper able to receive flowable material, an outlet at or near the bottom of the hopper, a rotatable member positioned below said outlet, so that flowable material falling in use from the outlet falls onto the rotatable member, 5 and means to adjust the rate at which said flowable material is dispensed by adjusting the rate of rotation of the rotatably member or by varying the distance between the outlet and the rotatable member or both.

Preferably said rotational member is a wheel.

Preferably said wheel has a smooth circumferential surface.

Preferably said flowable material is salt.

In a further aspect the invention consists in a method of dispensing flowable material from a hopper, the method comprising releasing the material from the hopper onto a rotatable member and adjusting the rate at which the flowable material is dispensed as and when required by varying the distance between the wheel and an outlet from the 15 hopper, or varying the speed of rotation of the wheel, or both.

Preferably said wheel has a smooth circumferential surface.

Preferably said method further includes the step of providing control means to control the adjustment of the rate at which the flowable material is dispensed. 8811ics2.398/CW/iv Preferably said rotatable member is a wheel. 272 8 2 Preferably the method further includes the steps of determining the actual rate of supply of the flowable material, determining the desired rate of supply of the flowable material by determining parameters of the rate of supply of a second material, calculating the difference between the actual rate of supply of the flowable material 5 and the desired rate of supply of the flowable material and altering the actual rate of supply of the flowable material in response to those differences.

Preferably the method further includes the steps of determining relevant parameters and the calculating said rates by means of software, firmware or the like.

In a still further aspect the invention consists in a method of making cheese 10 comprising the method of dispensing flowable materials as discribed in any preceding paragraph wherein the flowable material comprises or includes salt and the second material comprises or includes curd. In a still further aspect the invention consists in cheese when made by the method of the preceding paragraph. In a still further aspect the invention consists in a method of making cheese including the steps of adding salt 15 to curd by utilising an apparatus for dispensing flowable materials according to any one of the preceding paragraphs, or a method according to any one of the preceding paragraphs, or both, and varying the rate x>f supply of salt according to the rate of //74V :'C supply of curd. %.' ^ 0 Preferably said control means control the ^i^pl^of salt.

Preferably said control means includes sensors to sense the weight of curd being supplied, electronic processing means to receive information from said sensors, to 8811ics2.398/CW/iv 27 2 8 2 5 process the information and based thereon to vary the rate at which salt is dispensed, and suitable software within said processing means.

In a still further aspect the invention consists in cheese when made by the method of any one of the preceding three paragraphs.

In a still further aspect the invention consists in an auger comprising a helical member, at least some turns of said helical member being open at the centre thereof Preferably the turns of the auger are open towards one end of the auger and closed towards the other end.

Preferably said auger further comprises a central axle the open turns having a gap 10 between the turns of the helical member and said axle and the closed turns abutting or being closely positioned with respect to the axle.

Preferably said auger comprises a ribbon type auger.

Preferably said open turns comprise substantially half the length of said auger and said closed turns comprise substantially the remaining lengt^oPsaid auger.

Preferably means are provided to rotate the auger about the longitudinal axis thereof.

In a still further aspect the invention consists in a method of mixing and transporting material comprising the steps of providing an auger according to any one of the 8811ics2. 398/CW/iv Preferably said auger is contained within an outer 272 8 2 preceding paragraphs, mounting said auger at an angle to the horizontal with the open turns at the lower end of said auger, rotating the auger and introducing material at or near the lower end so that material is moved along the auger by said helical turns with some material returning through the central opening towards the lower end of said 5 auger, until material reaches the closed turns whereupon said material is moved along said auger without substantial return of the material.

In a still further aspect the invention consists in a method of making cheese including mixing at least curd and salt in an auger as above described or by a method as above described, or both.

In a still further aspect the invention consists in cheese when made in apparatus or by a method as above described.

To those skilled in the art to which the invention relates, many changes in construction and widely-differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the 15 appended claims. The disclosures and the description herein are purely illustrative and are not intended to be in any sense limiting.

One preferred form of the invention will now be described with reference to the accompanying drawings in which, p'c ; =>/; 8811ics2.398/CW/iv 2728 Figure 1 is a diagrammatic front view of a dispensing apparatus according to one preferred form of the invention, * Figure 2 is a side elevation of the apparatus of figure 1, Figure 3 is an enlarged view of a dispensing wheel for use in the apparatus of 5 figures 1 and 2, Figure 4 is a diagrammatic side elevation of an auger for use in the invention, Figure 5 is a side elevation of the auger of figure 4 in use, Figure 6 is a plan view of part of cheese making apparatus according to a preferred form of the invention, Figure 7 is a side elevation of the construction of figure 6, and Figure 8 is a schematic view of a control system useable in the invention.

Referring to figure 1 a hopper 1 for flowable material is provided. In the preferred form the hopper 1 contains salt which is to be added to curd during the process of cheese making. The hopper 1 can be fed by a further hopper 2 on an intermittent basis 15 as the level of salt in hopper 1 decreases. The hopper 1 has an outlet 3 at or near the lower end in use. A rotatable member preferably a smooth rotatable member such as a wheel 4 is provided below and close to the outlet 3. Thus the wheel 4 may be mounted on a bifurcated member 5 positioned adjacent the outlet, for example, by 8811ics2.n96/CW/iv being mounted onto the exterior of the hopper 1. Means are provided to drive the wheel and this may comprise a small electric motor 6, for example, desirably a variable speed motor driving the wheel 6 by means of an axle 7 and, for example, a gearbox 8 or other driving mechanism as suitable.

Means are provided to vary the speed of dispensing and this may be achieved either by varying the speed of the motor 6 or providing some adjustability in distance between the wheel 4 and the outlet 3.

The apparatus also provides a mixing device and this desirably comprises an auger 20 formed of helical turns preferably of a ribbon type. Some turns such as the turns in the region 21 are open at the centre as can be seen in both figures 4 and 5 whereas the turns at the end 22 are closed. The auger may be mounted on a central axle 23 with gaps such as 24 between the axle 23 and the helical turns in the region 21 but no substantial gaps in the region 22. The ribbon may vary from 10mm to 100mm by way of example.

In use a means such as a motor 25 is provided to rotate the central axle 23, for example, through a gearbox 26 and the auger is held at an angle to the horizontal. The angle shown in figure 5 is suitable but some on site variation may be required. Angles between 5° and 55° to the horizontal are expected to be suitable. The auger may be between 0.5 and 3 metres in length.

Material which may comprise, and in the preferred form does comprise, curd and salt is deposited at the lower end 30 of the auger and the rotating helical turns move the 883.lics2.n96/CW/iv 2728 material along the auger. Whilst in the area 21a proportion of the material drops back through the gaps 24 allowing substantial mixing to take place. Once in the region 22 the material is moved steadily along the auger to a discharge point. For an auger as described rollback of from 5% to 80% of the curd can be achieved.

The apparatus hereinbefore described can be combined in cheese making apparatus as shown in figures 6 and 7.

The apparatus within casing 15 supplies salt as above described to the auger in the region 16. Curd is moved inwardly along conveyor 30 to auger 31 where the curd is moved to auger 20 and deposited into the auger 20 in the region 32 for the mixing 10 above described to take place. Material exiting from auger 20 is moved along discharge auger 33 to belt 34 to be moved to the block forming station.

Referring now to Figure 8, incoming curd is weighed in any desired manner, for example, and preferably by a continuous weighing process, at 40 by any suitable sensor and this information is passed to a electronic processing means which has 15 software therein suitable to adjust the dispensing rate of the salt.

The sensors LSI and LS2 are used to sense the level of salt in the bulk hopper 2. If the level is too low salt is fed in at 41 to increase the level till a satisfactory height is reached. Salt is fed from the bulk hopper 2 to the dispensing hopper 1 through gate valve 42. If the weight of salt in hopper 1 falls below a desired level such as, for 20 example, less than 3kg the valve at 42 is opened until the desired weight, for example, 50kg or more is reached. A scale display unit provides the salt weight and suitable 8811ics2.n96/CW/iv 272 electronic processing means, operated by appropriate software written to achieve the functions shown in figure 8, stores the weight of salt in the hopper and the weight at the previous reading. If the gate 42 has not been open in the selected period between weighings then a figure Y is generated which is the difference in the two readings. 5 This reading Y divided by the time difference in seconds between readings gives weight per second which if multiplied by 60 times a weight figure per minute. Thus the kilograms per minute of actual salt flow is calculated.

Curd is fed in along an infeed conveyor at 40 and continuously weighed, the weight being displayed on a suitable readout at 43. The weight in kilograms x the length of 10 the conveyor x the rotation rate gives the curd flow rate in kilograms per minute. This information can be used to control the auger mixing speed but is also used to combine with the percentage of salt required to give a figure for the salt required in kilograms per minute. This is averaged over the time period previously selected and this figure minus the actual salt flow rate previously calculated gives a correction figure. 15 The correction figure may be rf or - and is displayed on a suitable screen. An alarm can be given in any suitable form if this is too large.

This error correction can be added to or subtracted from the salt required to give a figure indicated as Hz in the figure which is used to control the motor which rotates the salt wheel. Thus quick responses to changing curd inflow can be achieved in the 20 rotation rate or, if desired, the position of the salt wheel.

Thus it can be seen that at least in the preferred form of the invention apparatus is provided which enables a rapid response in the rate of salt dispensing with changes in 8811ics2.n96/CW/iv 2728 curd production. The apparatus enables the rate of salt dispensing to be matched to the time that the weighed curd will reach the mixing auger. The control is continuous and the salt wheel speed can still be varied even during hopper filling whereas in present apparatus during hopper filling only a standard salt dispensing rate is able to 5 be achieved. There are also particular advantages of the preferred forms of the invention wherein the ribbon type auger allows a smaller auger to be used which is easier to clean and is able to utilise standard drive mechanisms. Controlled mixing is achieved with no substantial increase in losses. Tha salt wheel dispenser allows a compact design to be achieved and also very quick if not instant response to salt flow 10 change requirements. Maintenance and cleaning is very easy to achieve. Utilising software control means that the control mechanism is not complicated and assists in achieving the short response times. This also allows the variations in rate of salt dispensing not to be inhibited by the filling of the hoppers. The wheel described enables a curtain of salt of accurate predetermined width and thickness to fall under 15 gravity into the curd at a predetermined but adjustable position as the curd exits the weighbelt.

As initial salt uptake into the curd is very rapid ie usually less than 5 seconds, the salt is more evenly spread within the curd particles prior to mechanical mixing. 8811ics2.n96/CW/iv 27 2 8 2 WHAT WE CLAIM IS: 1. An apparatus for dispensing flowable materials comprising a hopper able to receive flowable material, an outlet at or near the bottom of the hopper, a rotatable member positioned below said outlet, so that flowable material falling in use from the outlet falls onto the rotatable member, and means to adjust the rate at which said flowable material is dispensed by adjusting the rate of rotation of the rotatable member or by varying the distance between the outlet and the rotatable member or both. 2. An apparatus for dispensing flowable materials as claimed in claim 1 wherein said rotatable member is a wheel. 3. An apparatus for dispensing flowable materials as claimed in claim 2 wherein said wheel has a smooth circumferential surface. 4. An apparatus for dispensing flowable materials as claimed in any one of the preceding claims where said flowable material i? salt.

. An apparatus for dispensing flowable materials as claimed in any one of the preceding claims further including an auger comprising a helical member, at least some turns of said helical member being open at the centre thereof. 6. An apparatus for dispensing flowable materials as claimed in claim 5 wherein 27 2 8 7. An apparatus for dispensing flowable materials as claimed in either claim 5 or claim 6 wherein the turns of the auger are open towards one end of the auger and closed towards the other end. 8. An apparatus for dispensing flowable materials as claimed in claim 7 wherein said auger further comprises a central axle the open turns having a gap between the turns of the helical member and said axle and the closed turns abutting or being closely positioned with respect to the axle. 9. An apparatus for dispensing flowable materials as claimed in either claim 7 or claim 8 wherein said open turns comprise substantially half the length of said auger and said closed turns comprise substantially the remaining length of said auger.

. An apparatus for dispensing flowable materials as claimed in any one of claims 5 to 9 wherein said auger is contained within an outer casing. 11. An apparatus for dispensing flowable materials as claimed in any one of claims 5 to 10 wherein means are provided to rotate the auger about the longitudinal axis thereof. 12. An apparatus for dispensing flowable materials substantially as herein described with reference to the accompanying drawings. 8811QCS2.598/CW/jq tn O n 2728 2 5 13. A method of dispensing flowable material from a hopper, the method comprising releasing the material from the hopper onto a rotatable member and adjusting the rate at which the flowable material is dispensed as and when required by varying the distance between the wheel and an outlet from the hopper, or varying the speed of rotation of the wheel, or both. 14. A method as claimed in claim 13 wherein said rotatable member is a wheel.

. A method as claimed in claim 14 wherein said wheel has a smooth circumferential surface. 16. A method as claimed in any one of claims 13 to 15 further including the step of providing control means to control the adjustment of the rate at which the flowable material is dispensed. 17. A method as claimed in any one of claims 15 to 16 further including the steps of determining the actual rate of supply of the flowable material, determining the desired rate of supply of the flowable material by determining parameters of the rate of supply of a second material, calculating the difference between the actual rate of supply of the flowable material and the desired rate of supply of the flowable material and altering the actual rate of supply of the flowable material in response to those differences. 8811QCS2.598/CW/jq 2728 2 18. A method as claimed in claim 17 wherein said method further includes the steps of determining relevant parameters and the calculating said rates by means of software, firmware or the like. 19. A method of dispensing flowable material substantially as herein described with . A method of making cheese comprising the method of dispensing flowable materials as claimed in any one of claims 17 to 19 wherein the flowable material comprises or includes salt and the second material comprises or includes curd. 21. Cheese when made by the method of claim 20. 22. A method of making cheese including the steps of adding salt to curd by utilising an apparatus for dispensing flowable materials according to any one of claims 1 to 4, or a method according to any one of claims 13 to 15, or both, and varying the rate of supply of salt according to the rate of supply of curd. 23. A method as claimed in claim 22 wherein control means are provided to control the supply of salt. 24. A method as claimed in claim 23 wherein said control means includes sensors to sense the weight of curd being supplied, electronic processing means to receive information from said sensors ' " ' " mation and based reference to the accompanying drawings. 8811QCS2.598/CW/jq / / 1 u 1398 3 \ v \ 27 2 8 2 5 thereon to vary the rate at which salt is dispensed, and suitable software within said processing means.

. A method of making cheese substantially as herein described with reference to the accompanying drawings. 26. Cheese when made by a method according to any one of claims 22 to 25. 27. A method of mixing and transporting material comprising the steps of providing an apparatus for dispensing flowable materials according to any one of claims 5 to 11, mounting said auger at an angle to the horizontal with the open rums at the lower end of said auger, rotating the auger and introducing material at or near the lower end so that material is moved along the auger by said helical turns with some material returning through the central opening towards the lower end of said auger, until material reaches the closed turns whereupon said material is moved along said auger without substantial return of the material. 28. A method of mixing and transporting material as claimed in clr-im 27 and substantially as herein described with reference to the accompanying drawings. 29. A method of making cheese including mixing at least curd and salt in the auger of apparatus as claimed in any one of claims 5 to 11 or by a method as c . Cheese when made by a method as claimed in claim 29. 8811QCS2.598/CW/jq END OF CLAIMS in either one of claims 27 and 28.

James W Piper & Co Attorneys For: in cm co CNl r»» CM • • • •