Washing system, washing unit and method for use on a slaughter line
The present invention relates to a washing system for a slaughter line for the cleaning of the slaughter line's surfaces and machines comprising a washing trolley with one or more transport elements by means of which the trolley rests on a rod or rail and can be conveyed along the rod/rail by a transport mechanism and a washing arrangement with application devices for the application of cleaning fluid to the surfaces and machines.
In slaughterhouses operators regularly clean the walls and floor of the slaughter line and the machines for processing of the carcasses conveyed on the line. The machines often have a built-in cleaning function that can automatically carry out thorough washing and cleaning of the machines. Many machines also have a sterilisation function that sterilises the tools of the machines between each carcass.
In connection with the cleaning process, aerosols of cleaning fluids are formed, which can be a great nuisance for the operators in the room.
DE 202 02 477 Ul (NeuRo Metallbau) describes a device for the cleaning of the so-called "Hordenbδden" in malt factories. The device comprises a washing unit with rollers supporting a trolley on two parallel rods. The unit is moved along the rods by means of a transport mechanism comprising two pneumatic cylinders mounted on the unit. The cylinders have a hook that engages transverse pins on the rails and pulls the washing unit forward step by step along the rods. The unit has an oscillating bar with high-pressure nozzles that are supplied with water via a hose fixed at one end and following the washing unit at the other. When the unit moves from one end of the rods to the other, the high- pressure nozzles clean the surface of the "Hordenbδden".
This device is unsuited for the cleaning of the slaughter line's surfaces and machines as the surfaces to be cleaned are irregular in shape and require different washing programs. Furthermore, the transport mechanism necessary to move the trolley will be in the way of the semi and fully automatic machines of the slaughter line.
The object of the present invention is to provide an automatic washing system that can be used on a slaughter line and does not have the above-mentioned problems so that cleaning operations can be performed without the presence of operators and mounting of transport mechanisms are avoided, which mechanisms could affect the normal function of semi or fully automatic machines placed along the line.
The object is achieved with the washing system according to the invention, which system is characterised in that the rod/rail is made up of the slaughter line's sliding rod or transport rail in which the trolley is hung by means of transport elements, that the transport mechanism for the conveyance of the trolley along the rod/rail is made up of the slaughter line's transport mechanism which comprises carriers to actuate the transport elements and move the trolley along the rod/rail in the transport direction of then slaughter line, that the trolley has one or more tanks for cleaning fluid and that the washing system comprises a control system to register the position of the trolley on the slaughter line and controls the trolley's washing arrangement in dependency of the position.
The washing system according to the invention is capable of performing an automatic washing of the walls and floor of a slaughter line section having a sliding rod or transport rail of an already existing transport system with carriers to convey carcasses in the line's transport direction by actuation of the transport elements for the carcasses (chains, gambrels, hooks or the like). In addition, the system is capable of performing an automatic washing of machines placed in the same slaughter line section. This can take place without the assistance of operators so that they are not exposed to the mists of cleaning fluid resulting from washing and cleaning. If desired, it will thus be possible to use strong cleaning fluids that cannot be used when operators are present. Furthermore, the washing system is capable of cleaning operating machines without any danger to the operators, which will improve the cleaning result. The washing system of the invention makes use of the slaughter line's sliding rod/transport rail and transport mechanism and thus requires no mounting of special devices for transport purposes. The washing system according to the invention provides for labour savings, better hygiene and an improved working environment without affecting the normal functions of the slaughter line (except when cleaning is carried out).
The control system registering the position of the trolley on the slaughter line may have many different designs. The simplest design comprises a sensor registering when the washing trolley is moved onto the conveyor of the slaughter line. The sensor sends a signal to the control unit of the conveyor to keep track of the position of the trolley from this moment and to emit a signal when the trolley reaches certain positions. Another design has photo switches or similar selected places along the line so that a light ray is broken when the trolley passes to indicate that this position has been reached. A third possibility is to use the existing identification system of the slaughter line comprising reading stations and gambrels provided with a barcode for identification of the carcass on the gambrel. In this system the washing trolley can be equipped with special identification so that its position can be monitored via the reading stations. Other possibilities are the mounting of distance sensors in the walls or on the trolley, maybe combined with the emission of coded signals that are unique to an area of the slaughter line, or use of systems corresponding to those known in satellite navigation.
The system controlling the trolley's washing arrangement in dependency of the position of the trolley activates the relevant washing and cleaning devices of the washing arrangement when the trolley is positioned opposite the surfaces to be cleaned. The system can start a special washing program that is set according to the slaughter line area/machine to be cleaned. After a certain period or conveyance distance, the system stops the cleaning by actuating the washing arrangement, for instance by closing valves for cleaning fluid.
The control system registering the position and controlling the washing arrangement need not be a physical comprehensive unit, but can consist of separate elements communicating via wires or wireless signals such as radio signals. Part of the system may thus be mounted on the trolley and receive signals/data from a stationary unit. The control system preferably comprises a computer unit to perform calculations on the basis of registered data, for instance regarding operating times, speed etc. The control system operates the various functions of the washing arrangement, for instance the opening/closing of valves for cleaning fluid, adjustment of the mixing ratio, the movement of nozzles or mechanical cleaning devices, etc.
The trolley can comprise a tank for water, at least one tank for cleaning agent and a mixing aggregate mixing water and cleaning agent in the desired proportion. In this way it will be possible to use different mixtures of cleaning fluid and to use clean water for rinsing.
The application devices comprise preferably pumps with nozzles directing a jet of cleaning fluid towards the surfaces and machines to be cleaned. The nozzles may be mounted in a certain pattern in accordance with the surfaces to be cleaned, and/or they may be placed on moveable aggregates on the trolley to perform a movement directing the jet towards various surface parts. The nozzles can for instance be pivotally mounted on the trolley or be fitted on moveable arms.
The trolley can comprise devices for mechanical cleaning of surfaces and machines, preferably rotating brushes for brushing of the surfaces, which devices can be moved between a retracted, inactive position and an advanced, active position. The devices can be moveably mounted on the trolley to perform for instance an up-and-down movement or side-to-side movement. Cleaning fluid is preferably applied during the mechanical cleaning.
The trolley can be provided with means for drying the cleaned surfaces, for instance air blowers or brushes for dry brushing.
The trolley preferably carries an identification code such as a radio tag that can be read by the control system via reading stations to identify the trolley and its position so as to inform the control system about the washing program relevant to the particular slaughter line section and/or the machine in this section. The information can be transferred to the trolley via a wireless transmitter at the slaughter line and a corresponding receiver on the trolley. A calculation and control unit on the trolley can convert the information into signals controlling the trolley's pumps, motors etc. in accordance with a washing program.
The trolley can perform the cleaning while being conveyed along the sliding rod or the transport rail at the normal transport speed of the slaughter line conveyor, or means can be provided for temporarily disconnecting the conveyor's transport mechanism for instance
by lifting the carrier (drop finger) so that the cleaning is performed while the trolley is stationary opposite the surfaces or machines to be cleaned or allowing cleaning fluids etc. to be supplied from a stationary supply source.
Operation of the trolley requires at least cleaning fluid and electric power. The trolley can thus be provided with coupling means to engage with similar coupling means in one or more places along the slaughter line and thus receive the necessary supplies such as cleaning fluid for a fluid tank and electric power to charge a battery. If desired, the electric power can be supplied continually by means of a rail running parallel with the sliding rod/transport rail. Another possibility is to supply one or more cleaning fluids (for instance water) and electric power through hoses and wires following the trolley.
The washing system according to the invention can be used on slaughter lines with an overhead conveyor, i.e. preferably on lines for cattle or pig carcasses. On slaughter lines for pigs the system can be used on the section from where the stunned animals are shackled and through the sticking floor as well as through a scalding cabin, if any. Furthermore, it can be used on the section from the point where the dehaired carcasses are hung on gambrels or hooks through the singeing or flaming-off device up to and including the surface cleaning of the carcasses by brushing, scarping, whipping or the like. It can also be used on the clean section of the slaughter line for rectum removal, opening, evisceration, cleaning, free-cutting, splitting, automatic classification, etc. and further on in refrigeration rooms and equalisation rooms until the position where the carcasses are removed from the gambrels or hooks.
The washing system can be used on transport lines and machines where carcass parts on Christmas trees are conveyed and processed, including any intermediate storage. Thus, a "slaughter line" shall also comprise such processing lines and machines.
The trolley can be provided with a video camera to register a picture of the slaughter line's surfaces and/or machines and an image processing unit that analyses the picture with a view to selecting a cleaning program or controlling the efficiency of the cleaning, and a control unit to initiate, skip or stop a cleaning program or adjust it on the basis of the analysis.
It should be mentioned that the washing system according to the invention may be adapted to perform only some of the necessary cleaning processes of the slaughter line section, for instance if the machines already has a built-in cleaning function. The washing system may be adapted to perform only the essential cleaning so that when the mist of cleaning fluid has disappeared operators only have to carry out after-cleaning where this is appropriate. The washing system is used for instance between work shifts on the slaughter line at least once a day. In case of higher hygiene requirements it is possible to insert the trolley in the line of carcasses conveyed on the line so that more frequent washing is performed.
When the cleaning process has been completed for a slaughter line section, the trolley is returned to the starting position for instance via a return track and can from there carry out new treatment of surfaces and machines of the slaughter line section.
The transport element can for instance be one or more upper hooks sliding on a sliding rod of a slaughter line conveyor, or overlying track wheels running on a transport rail or rod.
The invention also relates to a washing unit for use in the washing system according to the invention comprising a washing trolley with one or more transport elements by means of which the trolley can rest on a rod or rail and can be conveyed along the rod/rail by a transport mechanism and a washing arrangement with application devices for the application of cleaning fluid to the surfaces and machines, and the washing unit is characterised in that the transport elements are designed to hang the trolley on the sliding rod or the transport rail of the slaughter line, that the transport elements have actuating surfaces for carriers in the slaughter line's transport mechanism by means of which the trolley can be moved along the rod/rail in the transport direction of the slaughter line, that the trolley has one or more tanks for cleaning fluid and that the trolley comprises positioning means by means of which a control system can register the position of the trolley on the slaughter line and control the trolley's washing arrangement in dependency of the position.
Furthermore, the invention relates to a method for use on a slaughter line for the cleaning the slaughter line's surfaces and machines, which method is characterised in that a washing system according to claim 1 is used.
The invention is explained in greater detail below with reference to the drawing showing a section of a slaughter line with a washing system according to the invention having means for communicating with the system's washing trolley and supplying it with consumables.
Through the section of the slaughter line runs a traditional overhead conveyor comprising a sliding rod 1 and a transport mechanism 2 with drop fingers 3. These convey carcasses suspended in gambrels in the fransport direction of the slaughter line by actuating the upper hook of the gambrel.
A washing trolley 4 is suspended in one or more upper hooks 5 similar to the upper hooks of the gambrels. The drop fingers actuate the hooks 5 in the transport direction of the slaughter line, and thus move the trolley at the speed of the slaughter line. When the trolley is to be stationary, a motor on the trolley operates an arm 6, which moves behind the upper hook and lifts the incoming drop fingers, thus preventing them from moving the trolley forward. When the trolley is to be moved forward, the arm moves away from the upper hook allowing a drop finger to grip the upper hook and push the trolley in the fransport direction of the line.
The trolley comprises a tank for water, a tank for cleaning agent and a battery capable of supplying the trolley motors with the necessary energy. The trolley is stationary when it is being supplied with water, cleaning agent and electric power via three outlets of an upright with couplings 7 corresponding to three couplings 8 on the trolley. When the trolley has been filled up, the couplings are released and the trolley is conveyed on the slaughter line by means of a drop finger engaging with the upper hook 5. "
A reading station is situated at a given place on the line to register the identity of the trolley by means of a radio tag 9, which is built into the upper hook. The control system of the washing system is now aware that the trolley is in a given position ready to perform a washing process. By means of a wireless transmitter symbolised by the aerial 10 the control system tells the trolley to perform a specific washing program selected depending on the information received by the control system, for instance that the walls 11 and a machine 12 must be cleaned thoroughly. Via a similar wireless transmitter symbolised by
the aerial 13 the trolley can inform the control system about position, condition, error messages, etc.
The trolley has forward-pointing nozzles 14, which are supplied with a mixture of water and cleaning agent, and direct water jets or atomised water particles towards the parts of the wall and floor surfaces to be washed. It also comprises three rotating brushes 15 fitted on arms 16 allowing them to be swung out to an active position in contact with the walls and the floor. By means of these devices the walls and the floor are washed while the trolley is conveyed on the slaughter line at the normal slaughter speed. When the trolley reaches the machine 12, the washing function is stopped by an internal or external signal and the brushes are pulled into the trolley again. The machine 12 receives a signal from the control system telling it to get ready to be cleaned and to retract the tools from the path of the trolley. The cleaning is performed by the trolley's application devices when the trolley has reached a position opposite the machine parts to be cleaned and perhaps been brought to a standstill. For simplification purposes these application devices are symbolised by a nozzle 17 placed on a moveable arm 18 allowing hard-to-reach places to be cleaned. The number of application devices and their functions and movements depend on the machine to be cleaned and on whether that machine has a built-in washing function.
After cleaning, the trolley moves again and may go to a new section of the slaughter line to clean the surfaces and machines of this section. Alternatively, it is moved to a return track and is returned to an up-stream position where it can be ready for a new washing process when this is needed. The trolley may have a motor allowing it to run at its own steam along a sliding rod so that it can move itself on sections of sliding rod with no transport mechanism, or can itself return to the starting position on the same sliding rod by moving opposite the line's direction of transport.
When the washing mist has cleared, operators can manually check the result of the washing process and perform any necessary after-treatments.
The trolley may have a video camera 20 to register a picture of the surfaces to be cleaned. By means of an image processing program it can be determined which washing program is the most suitable in the actual situation and a control system can then initiates this
washing program. The recordings of the video camera can also be used to check whether the effect of the treatment has been sufficient thorough so that the confrol system can extend the freatment time to obtain the desired result.