This application relates generally to wrapping machines used for wrapping food items and, more specifically, to a wrapping machine and associated pneumatic system that is suited for operation in cool environments.
Pneumatic systems, such as those used to control components in a trayed item (e.g., trayed meat items) wrapping machine, require consistent response times from all of the actuation cylinders and valves in the system and therefore must maintain dry air throughout the system. Water in such a pneumatic system will cause lubricants in cylinders and valves to break down and rust to build up on surfaces not tolerant to water. The result, assuming the cylinder or valve still functions, is typically slower or less consistent response times for the cylinder or valve to move from its home point to end of travel. This scenario may jeopardize any hard deadlines of an automated system to meet specific timing requirements.
It would be desirable to provide an automated wrapping system with a pneumatic arrangement that facilitates operation in a typical 90%+relative humidity and 40 degree Fahrenheit meat processing environment, yet can maintain a dry air actuation system to achieve consistent actuation response times.
In one aspect, a wrapping machine for wrapping trayed food products includes a plurality of pneumatic components that are actuatable by delivery of pressurized air to the pneumatic components. A pneumatic arrangement produces pressurized air for actuating the pneumatic components. The pneumatic arrangement is configured to reduce moisture in the pressurized air.
In another aspect, a wrapping machine for wrapping trayed food products includes a plurality of pneumatic components that are actuatable by delivery of pressurized air to the pneumatic components. A pneumatic arrangement produces pressurized air for actuating the pneumatic components. The pneumatic arrangement includes first and second receiver tanks connected in series along a flow path from the compressor to the pneumatic components.
In a further aspect, a wrapping machine for wrapping food products includes a wrap station at which food products are wrapped and a film dispensing system for drawing out film over food products at the wrap station. A conveying system moves food products along a path to the wrap station. A plurality of pneumatic components are provided, each pneumatic component actuatable by delivery of pressurized air, and a pneumatic arrangement produces pressurized air for actuating the pneumatic components. The pneumatic arrangement includes a compressor, first receiver tank and second receiver tank. The compressor tank includes an air inlet and an air outlet. The first receiver tank includes an air inlet fluidly connected to the air outlet of the compressor to receive pressurized air, the first receiver tank is sized to enable water in the pressurized air to condense, the first receiver tank includes a drain outlet for draining condensed water, and the first receiver tank has an air outlet. An air inlet of the second receiver tank is fluidly connected to the air outlet of the first receiver tank to receive pressurized air. The second receiver tank is sized to enable water in the pressurized air that enters the second receiver tank to condense, the second receiver tank includes a drain outlet for draining condensed water, and the second receiver tank having an air outlet that is fluidly connected to a path for delivery of pressurized air to the pneumatic components.
In yet another aspect, a wrapping machine for wrapping food products includes a wrap station at which food products are wrapped and a film dispensing system for drawing out film over food products at the wrap station. A conveying system moves food products along a path to the wrap station. A plurality of pneumatic components are provided, each pneumatic component actuatable by delivery of pressurized air, and a pneumatic arrangement produces pressurized air for actuating the pneumatic components. The pneumatic arrangement includes a compressor and a receiver tank. The receiver tank includes an air inlet fluidly connected to the air outlet of the compressor to receive pressurized air, and the receiver tank is sized to enable water in the pressurized air to condense, the receiver tank includes a drain outlet for draining condensed water, and the receiver tank has an air outlet. The receiver tank also has an air outlet fluidly connected to a path for delivery of pressurized air to the pneumatic components. A drain valve is associated with the drain outlet (e.g., downsteam along a drain path that is connected to the drain outlet). A controller is configured for controlling wrap operations of the wrapping machine, including controlling the conveying system, the pneumatic components and the compressor. The controller is also configured to selectively open the drain valve (i) upon completion of a wrap sequence and/or (ii) upon start-up of a wrap sequence.
In still another aspect, a wrapping machine includes wrap station at which food products are wrapped and a film dispensing system for drawing out film over food products at the wrap station. A conveying system moves food products along a path to the wrap station. A plurality of pneumatic components are provided, each pneumatic component actuatable by delivery of pressurized air. A pneumatic arrangement produces pressurized air for actuating the pneumatic components. The pneumatic arrangement includes a compressor with an air inlet and an air outlet, the outlet fluidly connected to a path for delivery of pressurized air to the pneumatic components. A pressurized air wand is connected to an outlet of the path such that pressurized air produced on-board of the wrapping machine can be selectively output by the pressurized air wand under manual control.
The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims.
Referring to
A weighing mechanism 34 is located at the inlet area for weighing the food product as it is placed into the machine. Once a stable weight is determined, the food product 16 is moved laterally into the machine through a light curtain imaging system 38 and past a height sensor array 40 for determining size of the food product and location of the food product on the conveyor. Part of the horizontal conveying system 18A may shift be shifted (e.g., into or out of the page in
Various motors M are shown and are used primarily for movement of the conveyor components, gripper components and underfolders. However, a plurality of pneumatic components are also provided for control of components, where each pneumatic component is actuatable by delivery of pressurized air.
In this regard,
The exemplary automated wrapping system includes a pair of pneumatic cylinders 62A, 62B to actuate the side clamps 32A, 32B, a set of pneumatic gripper cylinders 64A, 64B, 64C to actuate the gripping operation of the film gripper 24 (which has a center grip and two side grips), a pneumatic cylinder 66 to actuate the film knife assembly 30 to cut the film, a pair of film selector pneumatic cylinders 68A, 68B to select from the two film rolls, and a pneumatic cylinder 70 to actuate a label applier. All of these actuation points should be free from any material amount of water in the pressurized air system to operate at specific response rates required to wrap product in trays at desired speeds (e.g., 30 Packages Per Minute (PPM) or more). The system components described below help to develop pressure in the system and maintain a dew point in the system that is below the ambient temperature, even in low temperature environments.
The air flow of the system starts at the compressor 100 with arrows indicating the flow through all key components. The compressor 100 includes an air inlet and an air outlet and generates a high pressure (e.g., at least 120 PSI, such at least 130 PSI (e.g., a 135 PSI target)) as it moves air from the walk-in cooler environment into a closed pressure system. To reduce overall noise, the compressor 100 may be sized that is only needs to be operated at no more than a 50% duty cycle, such as at most a 40% duty cycle or at most a 35% duty cycle to provide adequate air pressure even when the wrapping machine is wrapping at a rated high speed of 25 or more PPM. However, even at a 30% duty cycle the negative by product of the compression is heat that will affect the dew point and should be removed, and a fan may be provided for this purpose. The compressor 100 is also pulling in high humidity air in the walk-in cooler environment, making it more difficult to create a dry pressurized air flow to the components.
The illustrated fluid connections between components may be formed of suitable tubing (e.g., copper and/or flexible). Tubing in the system between the compressor and a receiver tank 102 may be of a specified length and diameter (e.g., ½″ OD) to provide an adequate amount of flow of the 135 PSI system as well as a suitable surface area for the compressed air to cool as it travels to the air inlet of a receiver tank 102. An unloader valve 104 with associated pressure sensor is provided between the compressor 100 and receiver tank 102 to remove pressure in the supply line between the compressor 100 and the receiver tank 102 to allow the compressor to start without back pressure. The air outlet of receiver tank 102 feeds to an air inlet of a receiver tank 108. Receiver tank 102 includes a drain outlet 110 and receiver tank 108 includes a drain outlet 112. Drain outlet 110 feeds to a controllable drain valve 114. Here, the drain outlet 112 feeds along a path 116 into receiver tank 102 for eventual draining through drain outlet 110. However, alternatively drain outlet 112 could feed along a separate external path 118 to the input side of the drain valve 114.
The air outlet of receiver tank 108 feeds to path that leads to an air inlet of an auto drain trap 120, which in turn has an air outlet that feeds to an air inlet of another auto drain trap 122. A pressure regulator 124 is positioned between the two auto drain traps and reduces the pressure to a desired set level for component operation. The air outlet of auto drain trap 122 feeds to a low pressure dump valve 126, which in turn feeds to a valve manifold 128 with a plurality of controllable valves that enable controlled and selective delivery of pressurized air to the various pneumatic components.
Another valve manifold 130 selectively connects the high pressure air flow to the label applier cylinder, at either side according actuation desired. A vacuum pump 132 creates a vacuum pull along path 134 that also feeds through the valve manifold 130 for selectively controlling application of the vacuum to an label application wand 136 to hold a label at the end of the wand.
Notably, the receiver tanks 102 and 108 are positioned, sized and configured such that the hot, humid, high pressure air (e.g., at least 100 PSI) expands and cools since the surface of the tanks are cooled by the meat processing environment. In one example, each receiver tank may be cylindrical in configuration having a capacity of between about one and about three gallons. The expansion and cooling process forces moisture out of the compressed air through condensation, thereby lowering the moisture level in the pressurized air. The cool surface area of the first tank 102 causes condensation of the water as it passes thru the tank inlet, which condensation falls to the bottom of the tank 102. The air is subsequently cooled further within the tank during this first stage of condensation and cooling. Water can collect on the bottom of the tank 102. The water is expelled on a selective basis under control of the drain valve 114. Alternatively, the water in tank 108 drains along path 118. By using two receiver tanks instead of one, the likelihood of blow through of condensed water is reduced, and the overall tank surface area is increased and/or more effectively utilized. A pressure relief valve 115 may be provided on one or both of the receiver tanks to limit pressure within the tanks, and a pressure gauge 117 may also be provided for visual inspection by operators.
The high pressure air then enters the second receiver tank 108 for subsequent further cooling of the pressurized air and further condensation of remaining water in the pressurized air. Tank 108 is located above tank 102, and this condensed water is freely drained by gravity into the bottom receiver tank 102 for subsequent removal under control of the drain valve. The combined cooled surface area of the two receiver tanks 102 and 108, the volume of the tanks to handle water condensation and drain the water, and the high pressure force water droplets to separate from the pressurized air. The two downstream auto drain traps 120 and 122 provide a final filtering of the air in the system and expel any remaining condensed water particulates outside of the closed air system. The pressure reduction between traps 120 and 122 and resulting expansion of the air results in a lower dew point of the pressurized air at the downstream side of regulator 124. The result is a pressurized air flow from drain trap 122 having a dew point below the temperature of the ambient working environment of the machine (e.g., below 50° F.), which pressurized air is made available to the downstream components through the valve manifold 128. Because the dew point of the pressurized air is lower than the relatively cool temperature of the ambient environment, moisture condensation on the downstream side of the regulator 124 is significantly reduced and/or substantially eliminated from the system. The controller 50 is connected for selective control of each valve.
The drain valve 114 may be opened on a predefined basis for draining of condensed water. By way of example, in one implementation the drain valve 114 may be momentarily opened (e.g., for less than one second) to permit draining each time the wrapping machine is started to initiate a wrap sequence or operation (e.g., when a start button 160 (
The compressor 100 and receiver tank volume can be collectively sized such that adequate air pressure is made available for all pneumatic components to operate properly as necessary for sequential wrapping operations at a rated high speed of at least 25 PPM (such as at least 30 PPM), while at the same time requiring the compressor to be operated at no more than a 50% duty cycle (e.g., at most a 40% duty cycle or at most a 35% duty cycle). This reduces overall heat production by the compressor and also enables overall quieter operation of the machine. A pressure sensor may be used to control when the compressor is turned ON/OFF.
As seen in the rear perspectives of
The heat by product of the compressor 100 and/or vacuum pump 132 may also be put to use to warm film and the sealer belt by heat capture and flow along paths 140, 142 (
Notably, and referring again to
As shown, a pressurized air cleaning/drying wand 150 may be connected to a high pressure outlet 152 of the higher pressure zone. The high pressure outlet 152 may include a quick disconnect coupler to which a flexible feed tube 154 of the pressurized air cleaning/drying wand is connected for this purpose. The operator may selectively use the wand 150 for cleaning of the wrapping machine and/or the area around the wrapping machine. An openable/closeable valve 106 (e.g., manual lever valve or electrically/electronically controllable valve) may be provided along the flow path to the high pressure outlet 152 for controlling whether high pressure air is present at the outlet 152. The operator opens the valve when there is desire to use the wand 150.
It is to be clearly understood that the above description is intended by way of illustration and example only, is not intended to be taken by way of limitation, and that other changes and modifications are possible.
Number | Date | Country | |
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62408117 | Oct 2016 | US |