MXPA01006356A - Apparatus and method for controlling distribution of product in manufacturing process - Google Patents

Abstract

Apparatus and method for controlling the distribution of product items over a manufacturing line, in particular, for controlling the distribution of potato slices across the width of a fryer in a commercial potato chip manufacturing process, includes a number of sensors for measuring the moisture content of potato chips exiting the frying and a controller for determining whether a moisture content variation state exists that should be corrected. A number of rotatable flume distributors are provided which are controlled by the controller in accordance with position adjustment values in a look-up table corresponding to detected moisture content variations. The flume distributors are then adjusted to modify the distribution of potato slices across the fryer to reduce or eliminate the variation in moisture content of the chips leaving the fryer.

Description

APPARATUS AND METHOD FOR CONTROLLING THE DISTRIBUTION OF A PRODUCT IN A MANUFACTURING PROCEDURE BACKGROUND OF THE INVENTION FIELD OF THE INVENTION The present invention relates generally to an apparatus and method for controlling the distribution of a product and a manufacturing apparatus in a manufacturing process to improve the quality of the finished product. In particular, the invention relates to an apparatus and method for controlling the distribution of slices of food, such as slices of potato for potato chips, through a fryer in a form that compensates for the variation in the moisture content of the slices that come out of the fryer by correcting the distribution of slices that are delivered to the fryer across the fryer to minimize variations in the moisture content of the slices in the fryer.

DESCRIPTION OF THE RELATED TECHNIQUE Commercial production of potato chips typically involves a process in which the slices of potato are continuously fed to a hot oil vat, carried to hot oil by suitable means such as fins, conveyors and the like, and removed from the oil after an adequate time when the moisture content of potato chips has been reduced to approximately 1.3% to 1.4% by weight. The fryer in said process typically comprises an elongated tub or tank containing oil for frying at a temperature of about 365 ° C. Oil supply inlets and oil return outlets are adapted to the tank to provide a circulating supply of hot oil for frying potato slices. Potato slices are formed by supplying peeled raw potatoes to a number of centrifugal heads, which slice the potatoes into generally uniform slices of an appropriate thickness. The slices emerging from the slicing heads are then fed to a number of channels that carry the slices to a conveyor belt on which they are passed to the fryer. Channeling is typically done to achieve a generally uniform distribution of raw potato slices across the fryer. However, varying conditions of the fryer, such as changes in oil flow, oil temperature, movement of potato slices, may cause potato slices to be fried in a non-uniform manner, which may result in as a result finished fryings that have a relatively varied moisture content. This variation in moisture content can lead to consumer dissatisfaction with a perceptible freshness of the product. In addition, during the manufacturing process it is necessary to periodically shut off the individual slicers for the purpose of changing the slicing heads as a routine maintenance procedure. In the prior art process, this has resulted in an interruption in the production of chips due to the need to stop the entire line to remove the slicing head and change it. This procedure typically involves interrupting the supply of peeled potatoes to the slicers, waiting for the supplied slices to come off the line, stopping the line, removing and replacing the slicing heads or heads, starting supplying peeled potatoes to the slicers, and returning start the production line. The need to periodically change the slicing heads represents a drawback in the production process which decreases efficiency and restricts production. As a consequence, there is a need for improvements in technique to increase the regularity of a product quality, and to minimize production interruptions caused by the need to maintain the equipment.

BRIEF DESCRIPTION OF THE INVENTION The present invention provides an apparatus and method for improving the distribution of a product in a manufacturing process in order to increase the regularity of product quality. According to another aspect, the present invention provides an apparatus and method that eliminates the interruption of a production line to give routine maintenance to the equipment. In particular, the present invention provides the apparatus for controlling the distribution profile of product parts in a product manufacturing line, comprising the means for measuring a characteristic physical parameter of individual pieces of the product at a predetermined point on the line, means for comparing a characteristic measured parameter with a predetermined value and the means for changing the distribution profile of the product parts in the manufacturing line as a function of the result of the comparison. The present invention further provides, in accordance with another aspect, the apparatus for controlling the distribution of potato slices across a fryer in a commercial potato chip manufacturing line, comprising a plurality of slicing heads, each provided of a number of potatoes and forming from the potatoes a plurality of substantially uniform potato slices, and unloading the potato slices at their respective outlets, a plurality of channels operatively coupled to the outlets to transport the slices to a band conveyor, finishing each of the channels in a distributor to place the slices on the conveyor belt at a specific point, characterized in that at least one of the distributors is controllable rotating, a fryer to receive from the conveyor belt potato slices for frying and unload the potato chips produced from the slices in one of their outputs, a plura sensor close to the fryer outlet to detect the moisture content of potato chips coming out of the fryer as a function of fryer-wide placement and develop signals that represent moisture content, a controller which receives the signals and compares them with a set of predetermined values to determine if there are variations in the moisture content in potato chips as a function of placement across the width of the fryer and a look-up table containing the adjustment values of position for at least one controllable rotary distributor as a function of moisture content variation states, the control of the reference frame retrieving the position adjustment values by entering determined moisture content variation states and controlling the controllable rotary distributor to rotate to a position such that the distribution of the potato slices in the band The conveyor is changed so as to reduce the variation of moisture content.

BRIEF DESCRIPTION OF THE DRAWINGS Other features, benefits and advantages of the present invention will become apparent from the following description of the preferred embodiments taken in conjunction with the accompanying drawings in which: Figure 1 is a schematic diagram of the product manufacturing equipment in accordance with a preferred embodiment of the present invention; Figure 2 is an elevation view of a rotary channel in accordance with a preferred embodiment of the present invention; Figures 3A and 3B are diagrams illustrating the possible orientations of the variable angle rotating channels according to the present invention; Figure 4 is a flowchart of the operation of a controller in accordance with the present invention for adjusting the orientation of the slice channels; Figure 5 is a first example of a query box (LUT) containing the channel adjustment positions in accordance with the humidity variation; Figure 6 is a second example of a query box (LUT) that contains the channel adjustment positions in accordance with the humidity variation; and Figure 7 is a flowchart of the operation of a controller in accordance with the present invention for adjusting the orientation of the slice channels during shutdown for the maintenance of the slicing heads.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES The present invention will be described with respect to the apparatus for producing potato chips for explanatory purposes. However, it will be apparent to those skilled in the art that the invention can be applicable to any distributed product manufacturing process in which the uniform characteristics of the product depend on the parameters distributed during the manufacturing process. In a commercial process for making potato chips, a quantity of raw peeled potatoes is supplied to a plurality of centrifugal slicers 10a to 10d, which cut the potatoes into substantially uniform slices of a substantially uniform thickness. Such slicers are well known in the art, see for example, U.S. Patent No. 4,945,794, and therefore a description of their operation will not be provided herein. The raw potato slices 16 are taken from the slicers by means of a plurality of channels 12a to 12d to a washing band 18, where the raw slices are washed, before being delivered to the fryer 20, which contains a circulating amount of hot oil for frying. The slices are loaded in band 18 by means of a plurality of channel distribution ramps 14a to 14d. The slices are taken to the fryer by means of paddles or a similar mechanism (not shown) for a predetermined period, after which the resulting chips are removed from the fryer by means of a conveyor belt 22, such as a belt without end. The fritters are then passed through a plurality of humidity sensor heads 24a to 24c, which detect the moisture levels of the chips divided by the location in the left (24a), center (24b) and right (24c) bands. These heads are also well known in the art, and are available from Scientific Industrial Development Corporation under the name MM55. The sensor heads 24a to 24c convert the detected humidity levels into electrical signals and output the signals on the signal lines 26a to 26c to a programmable logic controller (PLC) 28. Based on the humidity readings received, the PLC 28 will adjust the orientation of the rotary channel ramps 14d and 14c to redistribute the raw slices 16 through the band 18 to compensate for and correct the variations in the moisture levels of the fryings coming out of the fryer in accordance with the left designations, center and right. These variations can be caused by variable conditions such as oil flow in the fryer, oil temperature gradients inside the fryer, migration of slices as well as other phenomena.

According to a preferred mode of operation as illustrated in Figure 4, the PLC 28 collects the moisture readings in step S40 and averages the left, center and right readings in a predetermined period in step S41. In step S42, the averaged readings are compared to the current variation limits, to determine if there are significant variations in the humidity level. For example, as shown in Figures 5 and 6, moisture levels within an acceptable range would be classified as "O" for "target level"; the levels on the scale would be classified as "H" for "high"; and levels below the scale would be classified as "L" for "low". In step S43, the results of the comparison are entered into the query tables (LUTs) as 50 in Figure 5 or 60 in Figure 6, to determine whether the adjustment of the rotary channel ramps 14b and / or 14c is necessary. The programmed settings in the LUTs are calculated by experimentation through the measurement and observation of a sufficient period of time. It is noted that in the preferred embodiment, the outer channel ramps 14a and 14d are stationary, and are oriented so that the slices will be placed just inside the outer edges of the band 18, while the inner channel ramps 14b and 14c They are rotating. Figure 2 is a side elevational view of the ramp 14b. As shown, an engine 141 operates a pulley or belt 142 that rotates a column 143 attached to the bottom of the ramp 14b. The channel ramps are rotated with the purpose of minimizing the variations in the moisture level of the frits that come out of the fryer. The possible arc of rotation of the inner ramps is established between a position that places the slices in the middle of the band 18 and a position that places the slices next to the corresponding outer channel ramp. Nearby sensors (not shown) detect when a ramp is at its outer limit, or in an area where collision with the other controlled channel ramp is possible. Limit switches (not shown) are provided inside the motor housing to determine when the motors have reached their limit of rotation. The scale of positions of each controllable ramp is calibrated on a scale of 0 to 100, with 50 denoting the central position, 0 denoting a complete position in the opposite direction to the clockwise (CCW) and 100 denoting a complete position clockwise (CW). Depending on the humidity readings, a ramp can give a large adjustment twist, a small adjustment twist or one without change. The degree of rotation that corresponds to "large" and "small" can be established adequately by means of the trial and error method. Figures 5 and 6 give examples of adjustments based on the calculated moisture level readings. For example, as shown in Figure 5, when the right side of the fryer has a "low" moisture reading, and the middle and left sides are within the target level, the ramp 14c will make a "large" movement in the direction opposite to the hands of the clock, while the ramp 14b will make a "small" movement in the opposite direction to the hands of the clock. This adjustment has the effect of redistributing the slices in the fryer so that more slices are supplied to the right side of the fryer. This is shown in Figure 3A. As shown in Figure 3B, when the readings indicate that the moisture level of the fryings on the left and right sides of the fryers are high, while the fryings in the center of the fryer are within the target range, the ramp 14c will make a "small" movement in the clockwise direction, while ramp 14b will make a "small" movement in a counterclockwise direction. This has the effect of reducing the amount of chips that are delivered to the left and right sides of the fryer to bring moisture levels to the target scale. The necessary settings are read in the LUTs by the PLC controller 28, and are converted into drive signals input to drive motors 141 through signal lines 30b and 30c. Figure 7 explains the operation of the PLC when a slicer needs to be turned off, for example for a change of slicing head. In step S70, the PLC continuously monitors whether a slicing head has been turned off. When a disconnection is detected, the current channel positions are stored in a memory in step S71. In step S72, the controllable channel ramps are rotated to the positions depending on the slicing head that has been turned off, so as to maintain a uniform distribution of slices in the fryer.

The PLC continuously monitors whether the slicing head has been returned in step S73. Once the PLC determines that the slicer has been placed back into service, the stored channel positions are retrieved from the memory, and the channels are restored to their previous positions in step S74. According to the invention, the system can also include a manual mode in which the channel positions can be manually adjusted. The system also provides "start" positions in which the controllable channels will be oriented at the beginning of the line. The "start" positions are predetermined positions that represent the optimal Start points to achieve a minimum variation of the moisture level in the fryer at the beginning. Additionally, gates are provided that are raised at the inlets of the slicing heads, so that the raw potato supply can be stopped at a specific slicer when it is necessary to turn it off to replace the slicing head. Although the present invention and embodiments described herein have been shown and described in detail in order to give a full explanation of the subject, the explanation given herein is not intended to limit in any way the scope of this invention which is also established in the appended claims.

Claims (18)

NOVELTY OF THE INVENTION CLAIMS

1. An apparatus for controlling the distribution profile of product parts in a product manufacturing line, comprising: means for measuring a characteristic physical parameter of individual product pieces at a predetermined point in said line; means for comparing a characteristic parameter measured with a predetermined value; and the means for changing the distribution profile of the product pieces in said production line as a function of the result of said comparison.

2. The apparatus according to claim 1, further characterized in that the product parts are distributed in the width of a conveyor belt, said apparatus further comprising a rotating distributor that places the product parts on the conveyor in an adjustable position of the conveyor belt.

3. The apparatus according to claim 2, further characterized in that the modifying means comprise a controller for sending a control signal to the rotary distributor to change the position when the result of the comparison indicates that the parameter measured is not equal to the value predetermined.

4. - The apparatus according to claim 3, further characterized in that the predetermined value is a scale and the measured parameter is determined as different from the predetermined value when the measured parameter is outside said range.

5. The apparatus according to claim 3, further characterized in that the controller comprises a programmable logic controller (PLC).

6. The apparatus according to claim 4, further characterized in that the piece of product is a slice of potato used to make potato chips, and the characteristic physical parameter is the moisture content of a potato fry formed in the line of manufacture.

7. The apparatus according to claim 6, further characterized in that the predetermined location is in an outlet of a fryer through which the slices of potato pass to become potato chips, the apparatus also including at least one sensor to detect the moisture content of the potato chips leaving the fryer, and transmission signals that represent the moisture content to the controller.

8. The apparatus according to claim 6, further characterized in that the slices of potato are formed from potatoes that are introduced to at least one slicing apparatus, the slices being transported to the distributor by a channel operatively coupled to an outlet of the slicing device.

9. The apparatus according to claim 8, further characterized in that a plurality of slicing devices and associated channels are provided, and characterized in that at least one of the plurality of channels includes a stationary, non-controllable distributor to place the slices of potato in a fixed position on the conveyor belt.

10. The apparatus for controlling the distribution of potato slices across a fryer in a commercial potato chip manufacturing line, comprising: a plurality of slicing heads, each provided with a quantity of potato and form from those potatoes a plurality of substantially uniform slices of potato, and that unloads those slices of potato in their respective outputs; a plurality of channels operatively coupled to the outlets for transporting the slices to a conveyor belt, each of said channels terminating in a distributor for placing the slices on the conveyor belt at a specific location, further characterized by at least one of the distributors it is rotatable in a controllable way; a fryer to receive the potato slices for frying from the conveyor belt and to unload the potato chips produced from the slices to an exit; a plurality of sensors near the fryer outlet to detect the moisture content of the potato chips leaving the fryer as a location function across the width of the fryer and emit signals that represent the moisture content; a controller that receives said signals and compares them to determine if there is variation in the moisture content between the potato chips as a location function across the width of the fryer; and a query box containing the position adjustment values for at least one controllable rotary distributor as a function of moisture content variation status; recovering the query box controller from position adjustment values by entering the determined moisture content variation states and controlling at least one controllable rotary distributor to rotate to a position such that the distribution of potato slices on the conveyor belt is changed in order to reduce the variation of moisture content.

11. A method for controlling the distribution profile of the product pieces in a production line of the product, comprising the steps of: measuring a physical characteristic parameter of the individual product pieces at a predetermined point in the line; compare a measured characteristic parameter with a predetermined value; and changing the distribution profile of the product parts in the manufacturing line as a function of the result of the comparison.

12. A method according to claim 11, further characterized in that the pieces of product are distributed across the width of the conveyor belt, including the manufacturing line a rotary distributor that places the pieces of product on the conveyor in a position adjustable on the conveyor belt.

13. A method according to claim 12, further characterized in that it comprises the step of sending a control signal to the rotary distributor to change the position when the result of the comparison indicates that the measured parameter is not equal to the predetermined value.

14. A method according to claim 13, further characterized in that the predetermined value is a scale and it is determined that the measured parameter is not equal to the predetermined value when the measured parameter is outside said scale.

15. A method according to claim 14, further characterized in that the piece of the product is a slice of potato used in the manufacture of potato chips, and the characteristic physical parameter is the moisture content of a potato fry formed in said manufacturing line.

16. A method according to claim 15, further characterized in that the predetermined location is in an outlet of a fryer through which the slices of potato pass to become potato chips, also including the manufacturing line by at least one sensor to detect the moisture content of the potato chips leaving the fryer, and transmit signals that represent the moisture content to a controller.

17. - A method according to claim 16, further characterized in that the potato slices are formed from potatoes that are introduced into at least one slicing device, the slices being transported to the distributor by means of a channel operatively coupled to an outlet of the slicing device.

18. A method according to claim 17, further characterized in that a plurality of slicing devices and associated channels are provided, and further characterized in that at least one of the plurality of channels includes a stationary, non-controllable distributor to place the slices of potato in a fixed position on the conveyor belt.