Method to operate a grinder during production

Abstract

The present invention relates to a method to grind mass in a grinder (1) wherein the mass is provided to the grinder (1) via a hopper (5) and transported by a feeder worm (2) to a rotating processing worm (3) which conveys the mass towards a cutting set (4) which grinds the mass and wherein the feeder worm (2) initially rotates in a first direction. During production the feeder worm (2) is periodically reversed and/or the speed of rotation of the feeder worm (2) is reduced in case the volume between the feeder worm (2) and the processing worm (3) tends to get blocked with the mass.

Claims

1. A method of operating a grinder, the method comprising: providing mass to the grinder via a hopper, the mass comprises frozen meat; transporting the mass by a feeder worm to a rotating processing worm, which conveys the mass towards a cutting set, the feeder worm is driven by a motor; reducing a speed of rotation of the motor of the feeder worm when a volume defined between the feeder worm and the processing worm is blocked with the mass, which occurs when a density of the mass is compressed to a predetermined level, which is sensed by a sensor or by a power consumption of the feeder worm or the processing worm.

2. The method according to claim 1, wherein the density of the mass is decompressed after the step of reducing the speed of rotation of the motor of the feeder worm, which is detected by the sensor or by the power consumption of the feeder worm and/or the processing worm.

3. The method according to claim 2, wherein after the density of the mass is decompressed, which is detected by the sensor or by the power consumption of the feeder worm or the processing worm, then the method comprises increasing the speed of rotation of the motor of the feeder worm.

4. The method according to claim 3, wherein the speed of rotation of the motor of the feeder worm is reduced to zero.

5. The method according to claim 4, wherein the grinder comprises a control unit, and the feeder worm rotates according to a preset pattern, wherein the control unit comprises a data-storage on which the present recipe is stored.

6. The method according to claim 4, wherein the grinder comprises a control unit, and the feeder worm rotates according to a preset pattern, wherein the method comprises inputting an identification into the control unit, and based on the identification the method comprises downloading the preset recipe to the control unit.

7. The method according to claim 6, wherein the feeder worm has a center axis and the processing worm has a center axis, and both of the center axis of the feeder worm and the center axis of the processing worm are in one vertical plane.

8. The method according to claim 1, wherein the speed of rotation of the motor of the feeder worm is reduced to zero.

Description

(1) The invention is now explained according to the only FIG. 1.

(2) FIG. 1 shows a grinder on which the inventive method can be executed. This grinder comprises a hopper 5, which accommodates the mass to be processed, e.g. blocks of frozen meat. At the bottom of the hopper 5 a feeder worm 2 is provided, which is driven by a motor and rotates during processing in a first direction around its longitudinal axis. Additionally, here below the feeder worm 2, a processing worm 3 is provided, which conveys the mass towards a cutting set 4, but which also comprises means to compress the mass. The cutting set comprises at least a perforated plate and a knife, which is driven by the processing worm and rotates relative to the perforated plate. Due to the cooperation of the perforated plate and the knife, for example minced meat is produced. During normal process conditions the feeder worm and the processing worm transport the mass in the same direction, the rotation direction depends on the design (winding direction) of the worm and/or the feeder worm and the processing worm rotate in the same direction of rotation.

(3) In a first embodiment of the invention the direction of rotation of the feeder worm 2 is reversed for a certain period of time and/or for a certain number of revolutions. Then the feeder worm is stopped again and reversed back to its initial direction of rotation. During this change of direction of rotation of the feeder worm the processing worm preferably maintains its direction of rotation and/or its speed of rotation. After the reversed rotation of the feeder worm, the feeder worm preferably rotates in the same direction and at the same speed as prior to the reversed rotation.

(4) In a second embodiment of the invention the rotational speed of the feeder worm will be reduced, preferably to zero for a certain period of time.

(5) In a third embodiment of the invention both the direction of rotation of the feeder worm and the processing worm remains the same and in order to prevent that volume 6 tends to get blocked with mass, the initial rotational speed of the feeder worm will be reduced relative to the initial rotational speed of the processing worm 3 such that the capacity delivered by the feeder worm will be lower than the capacity delivered by the processing worm. The reduction of rotational speed can start relatively early after a change in one or more relevant parameter(s) is sensed and depending on the sensed value an initial minor reduction of speed can be applied.

(6) Hence, the speed of rotation of the feeder worm is reduced proactively, before an undesired processing situation occurs.

(7) Reverse direction of rotation and/or the control of the rotational speed of the feeder worm can be initiated manually or automatically, for example by means of a sensor prior or after grinding, and/or by a recipe, which determines the treatment of the mass in the grinder. The sensor can sense one parameter of the mass, such as pressure, density, etc. and/or one or more parameters related to the drive of the feeder worm and/or the processing worm such as torque, current, voltage, power, and/or the design of the feeder worm and/or the processing worm. In a more preferred embodiment the entire process of reversing the direction of rotation and/or the control of speed of the feeder worm is controlled automatically based on the measured parameters and preferably related to the course of the measured relevant parameter(s). By relating the control to the course or the measured parameter will result in a gentle control wherein a reverse drive or control of speed only takes place for a short period of time.

REFERENCE SIGNS

(8) 1 Grinder 2 feeder worm 3 processing worm 4 cutting set 5 hopper 6 volume between feeder worm and processing worm