NL2015323B1 - A crate washing device having lateral guiding means and a method. - Google Patents

Abstract

The invention relates to a Crate washing device comprising a conveyor member, a guiding device and a nozzle device, the conveyor member being arranged for transporting crates in a transport direction T along a conveying plane C, the guiding device being located at an adjacent position at a predetermined side distance from the conveying plane C, and the nozzle device being arranged for ejecting a jet of cleaning fluid onto the crate, wherein the guiding device comprises a first and a second lateral guiding means provided at opposite sides of the conveying plane C, wherein the first and the second lateral guiding means each comprise a guiding wheel that provides a rotating contact surface with the crate for exerting a predetermined positioning force against sidewalls of the crate.

Description

A crate washing device having lateral guiding means and a method Field of the invention

The present invention relates to a crate washing device comprising a conveyor member, a guiding device and a nozzle device, the conveyor member arranged for transporting crates in a transport direction along a conveying plane, the guiding device being located at an adjacent position at a predetermined side distance from the conveying plane, and the nozzle device being arranged for ejecting a jet of cleaning fluid onto the crate, wherein the guiding device comprises a first and a second lateral guiding means provided at opposite sides of the conveying plane. The present invention also relates to a method of washing a crate.

Background of the invention

Crate washing devices are known in the art for cleaning crates after their use in a manner that after cleaning the crates can be reused to store any kind of fresh products. During the washing process, a crate is normally transported over a conveyor while a fluid is sprayed on the moving crate. In this manner, dirt that adheres to the crate is removed. Crate washing devices are typically used for high volumes of crates and should with a minimum of downtime A continuous flow of crates should be washed while any possible jam inside the washing device should be prevented. A crate washing device of this type is disclosed in EP1803 507 which has a longitudinal sliding plane along which a crate can be transported. The crate washing device comprises a number of nozzles spraying fluid on the transported crate for washing the crate. The crate washing device comprises a pair of overhanging, lateral counter-guides in the form of elongated side bars, which are elastically arranged in a transversal direction, with respect to the direction of the longitudinal sliding plane. When the crates are being washed, they are located between the lateral counter-guides along the entire length of the longitudinal sliding plane.

One of the disadvantages of the known crate washing device is that when returnable crates are transported, and when the lateral counter-guides are not properly adjusted, e.g. the space in between the counter guides is too broad and the pressure on a crate applied by the sprayed fluid is too high, the pressurized fluid can move the crate from its trajectory, causing the crate to crash against another crate on the trajectory or against an interior surface or part of the crate washing machine. Moreover, when the space in between the lateral counter-guides is too small, transport of the crate may be adversely affected because friction between the sidewalls of the crate and the lateral counterguides may be too high.

This type of crate washing device has an additional disadvantage that for crates of different sizes the space between the lateral counter-guides must be adjusted. In addition, such adjustment of the lateral counter-guides requires relatively long downtime and relatively high costs.

The present invention aims to overcome or mitigate at least one of the disadvantages of the prior art. It is therefore an object of the present invention to provide an apparatus and method for washing crates that offers a more efficient internal guiding system for the crates.

Summary of the invention

The object is achieved by a crate washing device as defined in the preamble, wherein the first and the second lateral guiding means each comprise a guiding wheel that provides a rotating contact surface for contact with a crate on the sidewalls of the crate so as to exert a predetermined positioning force against said sidewalls.

Advantageously, the rotating elements of the first and second lateral guiding means contact the crate that moves along the conveyor plane with their respective rotating contact surfaces and exert a positioning force on the crate. This provides that the crate is kept at a predetermined lateral position on the conveyor plane during its movement along the transport direction, while the crate is being washed. Moreover, when the crates are being sprayed by a washing fluid at relatively high pressure for cleaning the crate, the force exerted by the pressure of the fluid on the crate’s surface is compensated by the rotating elements of the first and second lateral guiding means and prevent any dislocation of the crate from the conveyor plane. By exerting the positioning force against the sidewalls of the crate, the crate remains at substantially a correct position on the conveyor plane and can continue to move along the transport direction.

Thus, the present invention provides a crate washing device with an effective guiding system that is capable of holding the crates while they are transported and washed during the washing process.

In an embodiment of the invention the guiding wheel is rotatably arranged around a rotation axis perpendicular to the transport direction and parallel to each other.

In this manner, when the crates are washed, the guiding wheels will be in rotating contact with the sidewalls of the crates, allowing easy movement of the crates along the transport direction. Moreover, by having a guiding wheel at each side of the crate while being transported, friction against the sidewalls of the crate is low. Furthermore, this provides a washing device having a guiding system capable of holding the crates while they are transported and exposed to the washing process.

By adjusting the orientation of the rotating axis of the guiding wheel and/or the shape of its contact surface, the positioning force can be configured with respect of its direction: the positioning force can have as components one or more of a downward force, lateral force and a parallel force.

The downward force component provides a force on the crate that presses the crate against the conveyor plane. The lateral force component provides a force on the crate along the conveyor plane lateral to the transport direction. The parallel force component provides a force on the crate along the transport direction.

The positioning force provides a steady and stable contact of the crate with the guiding wheels, while the crate is cleaned and transported along the conveyor. Since the positioning force prevents dislocation of the crate, a continuous flow of crates can be transported without disruptions. Downtime due to crashes of crates on the conveyor plane can be prevented, i.e., minimized.

In an embodiment, the position of the guiding wheel along the transport direction T is adjustable in a lateral direction with respect to the transport direction.

This provides a flexible arrangement of the crate washing machine and more specifically of the rotating elements, to adapt to various crate sizes without the need of major changes to the crate washing machine.

In an embodiment of the present invention, the guiding wheels are rotatably mounted on a base element providing a connection member for the guiding wheels such that the guiding wheels can be adjustably positioned at opposite sides of the conveying plane. Moreover, the base element comprises a limiting element provided for delimiting lateral movement of the rotating element in the lateral direction.

By having each of the guiding wheels mounted on a respective base element and by providing each of the guiding wheels with a limiting element, the invention allows automatic adjustment of the guiding wheel before, during and after contact with the sidewalls of the crate. Moreover, by delimiting lateral movement of the guiding wheels the limiting element will set the positioning force that the rotating elements can exert on the sidewalls of the crate, in dependence of the width of the crate and the lateral distance in-between the guiding wheels.

In an embodiment, each of the first and second guiding means comprises an elastic element that is connected between the guiding wheel and the base element for allowing elastic adaptation of the distance between the first and second guiding means in the lateral direction.

In this manner, the lateral distance between the first and second guiding means can be elastically adapted depending on the width of the crate passing between the first and second guiding means. Thus adjustment of the lateral distance between the first and second guiding means dependent on the width of the crate is automatically done.

Moreover, by having the configuration of the elastic element that is connected to the guiding wheel and the base element, adjustment of the guiding means in respect of the dimensions of the crates is not required, because the elastic element will allow elastic displacement of the guiding wheels to accommodate a crate between the guiding wheels so as to move the guiding wheels relative to each other in a direction perpendicular to the transport direction.

Moreover, the elastic element comprises a first end connected to the guiding wheel and a second end connected to the base element such that the elastic element pivotably connects the guiding wheel to the base element.

By having the elastic element connecting the rotating element to the base element, the rotating element is provided with certain elasticity that allow some elastic displacement of the rotating element when engaging the sidewalls of the crate. The elastic element acts as a spring element that exerts a positioning force on the crate.

In an embodiment, the elastic element is a spring element comprising a predetermined spring constant of about 0.5-1.5 N/cm.

This provides sufficient positioning force of the rotating element on the crate while the nozzles are spraying washing fluid that could displace the crate. Moreover, by having a spring element with a spring constant of this range, the rotating elements retain the crates in their position along the transport direction without causing any damage to it.

In an embodiment, the contacting surface of the guiding means is provided with a thermoplastic material or a rubber-like material.

By providing the rotating contact surface with such a material, damage of the crates due to contact with the rotating contact surfaces during operation of the crate washing device can be prevented.

In an embodiment of the invention, the predetermined positioning force exerted by the guiding wheels is about a minimum of 10 N.

This value is considered to be sufficient to retain the crate in the conveying plane and to allow movement of the crate in the transport direction during operation. Additionally, this provides the possibility to spray the washing fluid at a high pressure, while the guiding wheels can compensate for the impact force of the pressurized washing fluid.

Another aspect of the present invention relates to a method for transporting a crate in a crate washing device, the method comprising the steps of: - introducing a crate in a crate washing device in a transport direction along a conveying plane with a bottom of the crate parallel to the conveying plane and sidewalls of the crate extending in an upward direction, - contacting the sidewalls of the crate in a lateral position by a first and a second lateral guiding means at the sidewalls, - wherein the first and the second lateral guiding means each comprise a rotating element providing a rotating contact surface for exerting a predetermined positioning force against the sidewalls of the crate.

The method provides a simple manner to retain a crate in a bottom-down position along the conveying plane while being washed.

Also the method can be time-efficient, because crashes between consecutive crates can be avoided. The distance between two consecutive crates along the conveyor plane inside the crate washing device can be set to a minimal distance of less than the total length of the crate. By having a rotating element at each side of the sidewalls of the crate to exert a positioning force on the crate, the crate can be washed without dislocation of the crate due to exposure to a pressurized washing fluid and can be kept in position throughout the washing process.

The rotating element comprises a guiding wheel being rotatably arranged around a wheel rotation axis perpendicular to the transport direction.

Advantageously, this provides assistance to the transport movement of the crate while being washed, without compromising the integrity of the crate.

Moreover, after contacting the sidewalls of the crate, the guiding wheels assist the transportation of the crate to a subsequent station along the transport direction in the conveying plane. Additionally, when contacting the sidewalls of the crate by the first and the second lateral guiding means, a washing fluid is sprayed against one or more surfaces of the crate at pressure larger than 60 bar, preferably larger than 10 bar, and most preferably larger than 110 bar in a direction that is transverse to the conveying plane.

In this manner, the washing method can be performed at an optimal transport speed, due to the fact that the pressure of the sprayed washing fluid will not affect to the position of the crate, while dirt particles can be effectively removed. Moreover, the surfaces of the crate can be cleaned in a relatively short period of time when compared with other methods.

Advantageous embodiments are further defined by the dependent claims.

Brief description of the drawings

Further characteristics and advantages of the invention will become apparent from the description of a preferred but not exclusive embodiment of a crate washing device, illustrated by way of a non-limiting example in the accompanying drawings, wherein:

Figure 1 illustrates a side view of the crate washing device according to an embodiment of the invention;

Figure 2 illustrates a front view of the crate washing device according to an embodiment of the invention;

Figure 3, illustrates a perspective exploded view of the guiding means according to an embodiment of the invention; and

Figure 4 illustrates a perspective view of the guiding means according to an embodiment of the invention.

Detailed description of the embodiments

Figure 1 shows a crate washing device 1 according to an embodiment of the present invention. The crate washing device 1, also referred to as crate washing machine, is designed for washing crates in a bottom-down position. The crate washing machine 1 comprises a conveyor member 2 for transporting crates 3, as can be best seen in figure 2, along a conveying plane C in a transport direction T. The crate 3 is moved in the transport direction T, below a first nozzle device 4 situated at a predetermined distance from the conveying plane C for ejecting a washing fluid against the crate 3 in a spraying direction S. The conveyor member 2 as shown is an endless belt or endless conveyor belt. The endless belt 2 provides movement of the crates 3 in one direction. The conveyor member 2 extends along the entire length of the crate washing machine 1, and extends between a first and a second end 14, 15 of the crate washing machine 1. The endless belt 2 allows the continuous washing operation of crates 3 by the crate washing machine 1. The skilled person will appreciate that the speed of the conveyor member 2, and consequently of the crates, can be adjusted. The speed will be determined by the efficiency of the washing process and will depend on many factors, inter alia, including the number of nozzle devices, the pressure at which each of the nozzle devices sprays the washing fluid, the composition of the washing fluid and its temperature.

It is not illustrated, but the skilled person will appreciate that the crate 3 enters in the bottom-down position at the first end 14 of the crate washing machine 1 and remains in this position during its entire washing process within the washing device 1.

The crate washing machine 1 as shown comprises a number of nozzle devices 4, 4’, 5, 5’, 6, 7 for spraying the washing fluid at different positions and at different angles inside the washing device 1. Upon entry into the crate washing machine 1, the crate 3 contains dirt adhered to its walls. When the crate 3 enters the crate washing machine 1, it is moved in the transport direction T. During the washing of the crate 3, it is firstly positioned under a first set of nozzle devices 4, 4’, 5, 5’, where the washing fluid is sprayed on the crate surfaces at a relatively high pressure. Then, the crate 3 will be moved forward in the transport direction T along the conveying plane C until it reaches a position below a second set of nozzles devices 6, 7 and the washing fluid is sprayed at a high pressure. The first set of nozzles devices 4, 4’, 5, 5’ will be hereafter referred to as pre-rinse nozzles, while the second set of nozzles devices 6, 7 are will be hereafter referred to as impact nozzles. The pre-rinse nozzles 4, 4’, 5, 5’ are configured to wet, moisten and clean up the dirt particles from the surfaces of the crate 3. The impact nozzles 6, 7 are configured to scoop out or to remove the dirt particles over the edges of the walls of the crate 3. In this manner, the crate has been cleaned when it reaches the second end 15 of the crate washing machine 1.

It should be noted that the pre-rinse nozzle devices 4, 4’, 5, 5’ are configured to spray washing fluid at a relatively high pressure, but not too high because this could make the crate 3 move from its initial position on the conveyor belt. The impact nozzles 6, 7 are configured to spray washing fluid at a relatively high pressure of at least about 100 bar or higher than 110 bar, typically higher than during pre-rinse When the crate 3 is sprayed with washing fluid at this high pressure, the stability of the crate in the conveying plane C is compromised. When the washing fluid is sprayed at the above-mentioned high pressure, the impact nozzle sprays the washing fluid in a form of the blade-shaped spray that hits the crate and is able to displace the crate 3 from the conveying plane C and from its intended trajectory. In order to avoid this displacement in the form of lateral movement of the crate, the crate washing machine 1 comprises a first and a second guiding area 8, 9 provided with a total number of three pairs of lateral guiding means 10, 11, 12, 13 as shown in the embodied example of figure 2. These pairs of lateral guiding means 10, 11, 12, 13 are in the form of a guiding wheels positioned in a specific configuration pairwise opposite to each other on opposite sides of the conveying plane, being at a distance from each other and in groups of three pairs per guiding area 8, 9. It is noted that the invention is not limited to embodiments having three pairs of lateral guiding means, but may have two or more pairs.

The first guiding area 8 comprises a first and a second guiding wheel 10, 11 provided between a nozzle device 4’ and a nozzle device 6. The first and the second guiding wheels 10, 11 form a first pair of guiding wheels. The guiding wheels 10, 11 are provided at a distance E from the nozzle device 4’ and also at a distance F from the prerinse nozzle device 6. The distances E and F can be the same or different. Moreover, the distance G between the pre-rinse devices 4, 4’, 5, 5’ and the impact nozzle devices 6, 7 are at least equal to one crate length. As shown, the first set of guiding wheels 10, 11, provided in the transport direction T, are situated at a predetermined distance from the pre-rinse nozzle devices 4, 4’, 5, 5’ and the impact nozzles 6, 7. In this manner, when the crate 3 is transported from the pre-rinse nozzle devices 4, 4’, 5, 5’ to the impact nozzles 6, 7, the crate 3 is engaged by the first pair of guiding wheels 10, 11 such that these wheels exert the positioning force on the sidewalls of the crate 3 before the crate is sprayed by washing fluid from the impact nozzle devices 6, 7. It should be noted that the first pair of guiding wheels 10, 11 are also provided at a position under the pre-rinse nozzle devices 4, 4’, 5, 5’.

As shown in figure 1, a divider element 18 is provided inside the crate washing machine 1 at a distance H from the second nozzle device 7. The divider element 18 is securely connected to an interior top part or side part of the crate washing machine 1 in such a way that when the dirt particles are scooped out or removed from the crates by the sprayed fluid, their trajectory does not extend beyond the limits of the second end 15 of the crate washing machine 1.

The skilled person will appreciate that the divider element 18 may be provided at different locations inside the crate washing machine 1 at for instance a location adjacent to any of the nozzles. Under such circumstances, when the nozzles spray washing fluid, the particles adhered to the surfaces of the crates 3 are released and by means of the divider element 18 are directed towards a bottom part of the crate washing machine 1. In this manner, the particles can be collected, in a collecting point (not illustrated) located at the bottom part of the crate washing machine 1, and then extracted, at an extraction point (not illustrated). The divider element 18 prevents particles, which have been scooped out or removed from the surfaces of the crate 3, from dropping or falling back to the crate 3 while moving in the transport direction T.

At each end 14, 15 of the crate washing machine 1 a first and a second transfer unit 16, 17 are provided. These transfer units 16, 17 are connected to the crate washing device 1 to provide a connecting transport surface to an adjacent crate handling station (not illustrated). Each of the transfer units 16, 17 comprises a conveyor element for transporting crates 3 from a preparation-station (not illustrated) to the crate washing machine 1, and from the crate washing machine 1 to a next station or device (not illustrated). It should be noted that the horizontal position of the first and second transfer units 16, 17 relative to the crate washing machine 1 could be adjusted along the transport direction T. This adjustment will be made depending on the crate size. The distance between the second end 14 of the crate washing machine 1 and the second transfer unit 17 can be adjusted in the same fashion. By adjusting the distance between the first and second transfer units 16, 17, and the first and second ends 14, 15 of the crate washing machine 1, different crates sizes can be easily introduced into the crate washing device 1. In this manner, long or short crates can be washed with the crate washing machine 1, and no further operations need to be performed in order to adapt the device itself. This provides a flexible crate washing machine that can be used to wash crates or other types of containers of various sizes.

In figure 2, a front view of the crate washing machine 1 is shown, wherein the crate 3 is transported and simultaneously engaged at each sidewall by the pair of guiding wheels 10, 11. The first and second guiding wheels 10, 11, 12, 13 are provided at each side of the conveying plane C at a distance D, which is about the width of the crate 3. As shown, the crate 3 is located at a vertical distance from the impact nozzle devices 6, 7.

In an embodiment, the crate 3 has a length of at least about 40-60 cm, and a width of about 30-50 cm. The crate 3 walls are about 20-45 cm in height.

Each of the guiding wheels 10, 11, 12, 13, is mounted on a side rail 20, 21. These side rails 20, 21 are located at a position adjacent to each side of the conveyor member 2. The guiding wheels 10, 11, 12, 13 are securely connected to the side rails 20, 21 by means of fastening means (not illustrated) that are fastened to a base element 33, which is shown in figures 3 and 4.

As shown in figure 2, the crate washing machine 1 is provided with a housing 22, which encloses the hardware parts of the crate washing machine. The housing 22 comprises a number of windows 23, 24, 25, 26 that are securely sealed against any possible leak of the washing fluid or dust particles, and that enable the user to inspect the washing process from the exterior of the crate washing machine 1. Optionally, a pair of side windows 23, 26 are provided with a handle 31, 32 to allow easy opening of these windows. The windows 23, 26 can be pivotably or slideably opened.

Moreover, the housing 22 comprises a top unit 27 enclosing the impact nozzle devices 6, 7. It should be noted that the impact nozzle devices 6, 7, as well as the pre-rinse nozzle devices 4, 4’, 5, 5’ are hung from the top part of the housing 22. This configuration provides the possibility to have a very compact crate washing machine 1.

As shown, the crate washing machine 1, including the housing 22, is supported by at least a pair of legs 29, which each are mounted on an adjustable wedge 30 allowing height adjustment of the crate washing machine 1.

Figures 3 and 4 illustrate the guiding means in the form of the guiding wheel 10, 11, 12, 13 in an exploded view and assembled view, respectively. As shown in figure 3, the guiding wheel 10, 11, 12, 13 is in the form of a hollow wheel, which houses in its interior a number of items that will now be described in detail. As already mentioned with reference to figure 2, the guiding wheel 10, 11, 12, 13 is mounted on the base element 33. The base element 33 is a rectangular base plate, which comprises a pair of openings 33’ that allow the fastening means (not illustrated) to securely connect the base element 33 to the side rails 20, 21 of the crate washing machine 1. The base element 33 comprises a top surface having a pivoting element 34 and a blocking element 35. As shown, the blocking element 35 is positioned with an orientation having an acute angle a with respect to the pivoting element 34. The acute angle a is about 30°-60°. It should be noted that the pivoting element 34 would allow the guiding wheel to rotatably pivot in a direction until it reaches the blocking element 35. This can be converted into the biasing movement of the guiding wheel 10, 11, 12, 13 with respect to the base element 33.

The guiding wheel 10, 11, 12, 13 further comprises a connecting element 36 having a base part 39 and a pair of connecting rods 37, 38 of different heights. Each of the connecting rods 37, 38 is connected to the base part 39 of the connecting element 36 and more specifically, at a position adjacent to the side edges of the base part 39. A first connecting rod 37 comprises a ring element 41 provided at a position adjacent to a lower part of the first connecting rod 37. The ring element 41 surrounds the outer periphery of the first connecting rod 37. A second connecting rod 38 comprises a torsion spring 40 sleeved in the outer periphery of the first connecting rod 37. The torsion spring 40 comprises a first and a second end leg 42, 43. The first end leg 42 of the torsion spring 40 is positioned against the middle part of the first connecting rod 37, and the second end leg 43 of the torsion spring is positioned against the lower end of the first connecting rod 37, and more specifically, under the ring element 41 of the first connecting rod 37.

In this manner, when the guiding wheel 10, 11, 12, 13 is in rotational operation, the torsion spring 40 is subjected to torsion or twisting, that is, the torsion spring is storing mechanical energy. When the torsion spring 40 is twisted, it exerts a biasing force (actually torque) in the opposite direction of the twist. This force is proportional to the amount it is twisted, i.e., the twisting angle, and will provide as a reaction force the positioning force of the guiding wheel 10, 11, 12, 13 against the sidewalls of the crate.

Moreover, the guiding wheel 10, 11, 12, 13 comprises a number of bearing sleeves 44 provided to fit onto the different parts to which these are directly connected. Moreover, each of the bearing sleeves 44 is provided to assist rotation of the different parts to which the bearing sleeves 44 are associated. The guiding wheel 10, 11, 12, 13 further comprises in its top part a through hole 45, wherein a screw 46 securely connects to the bearing sleeve 44. The screw 46 is connected to the first connecting rod 37 to provide a rotating point to the guiding wheel 10, 11, 12, 13.

In figure 4, the guiding wheel 10, 11, 12, 13 comprises around its outer periphery a contacting element 47. The contacting element 47 in provided with a contacting surface with which the guiding wheel 10, 11, 12, 13 contacts with the sidewalls of the crate 3. The contacting element 47 can be made of a polymeric material, a rubber-like material or any other suitable material.

As shown in figure 4, when the guiding wheel 10, 11, 12, 13 is assembled with the base element 33, the internal parts as shown in figure 3 are securely protected and not visible. In this manner, when the crate washing machine 1 is in operation, the internal parts of the guiding wheel 10, 11, 12, 13 will remain clean and dry. This provides a long lasting working period for such an assembly before any maintenance operation is required.

Thus, the invention has been described by reference to the embodiments discussed above. It will be recognized that these embodiments are susceptible to various modifications and alternative forms well known to those of skill in the art without departing from the spirit and scope of the invention. Accordingly, although specific embodiments have been described, these are examples only and are not limiting upon the scope of the invention.

Reference numerals: 1. Crate washing device/ crate washing machine 2. Conveyor member 3. Crate 4. First nozzle device 4’. Nozzle device 5. Nozzle device 5'. Nozzle device 6. Nozzle device 7. Nozzle device 8. First guiding area 9. Second guiding area 10. Lateral guiding means/Guiding wheel 11. Lateral guiding means/Guiding wheel 12. Lateral guiding means/Guiding wheel 13. Lateral guiding means/Guiding wheel 14. First end of the crate washing machine 15. Second end of the crate washing machine 16. First transfer unit 17. Second transfer unit 18. Divider element 19. - 20. Side rail 21. Side rail 22. Housing 23. Window of the housing 24. Window of the housing 25. Window of the housing 26. Window of the housing 27. Top unit of the housing 28. - 29. Legs of the housing 30. Adjustable wedge 31. Handled of the window 32. Handled of the window 33. Base element 33'. Openings of the base elements 34. Pivoting element 35. Blocking element/Limiting element 36. Connecting element 37. First connecting rod 38. Second connecting rod 39. Base part of the connecting element 40. Torsion spring/Elastic element 41. Ring element of the first connecting rod 42. First leg of the torsion spring 43. Second leg of the torsion spring 44. Bearing sleeve 45. Through hole of the guiding wheel 46. Screw 47. Contacting element

Claims (15)

A crate washing device (1) comprising a conveyor device (2), a guide device and a nozzle device (4, 4 ', 5, 5', 6, 7), wherein the conveyor device (2) is adapted for transporting crates (3) in a conveying direction T along a conveying surface C, the guiding device (10, 11, 12, 13) being situated at an adjacent position at a predetermined lateral distance from the conveying surface C, and the nozzle device (4, 4 ', 5, 5' 6, 7) is arranged for ejecting a jet of cleaning fluid onto the crate (3), wherein the guide device comprises a first and a second lateral guide means (10, 11, 12, 13) provided on opposite sides of the conveying surface C characterized in that the first and second lateral guide means (10, 11, 12, 13) each comprise a guide wheel that provides a rotating contact surface with the crate (3) for exerting a predetermined positioning force against the side walls of the crate ( 3). The crate washing device (1) according to claim 1, wherein the guide wheel (10, 11, 12, 13) is rotatably arranged about an axis of rotation perpendicular to the transport direction T and parallel to each other. Crate washing device (1) according to claim 1 or 2, wherein the positioning force is composed of and or more of a downward force, lateral force and a parallel force, relative to the direction of transport. Crate washing device (1) according to claim 2 or 3, wherein the position of the guide wheel (10, 11, 12, 13) along the conveying direction T is adjustable in a lateral direction relative to the conveying direction T. Crate washing device (1) according to one of the preceding claims, wherein the guide wheels (10, 11, 12, 13) are rotatably mounted on a base element (33) which provides a connecting member for the guide wheels (10, 11, 12, 13) , such that the guide wheels are adjustably positioned on opposite sides of the conveying surface. The crate washing device (1) according to claim 5, wherein the basic element (33) comprises a limiting element (35) provided for limiting lateral movement of the rotating element in the lateral direction. Crate washing device (1) according to one of the preceding claims, wherein each of the first and second guide means (10, 11, 12, 13) comprises an elastic element (40) which is connected between the guide wheel and the basic element (33) for allowing elastic adjustment of the distance D between the first and second guide means (10, 11, 12, 13) in the lateral direction. The crate washing device (1) according to claim 7, wherein the elastic element (40) has a first end (42) connected to the guide wheel (10, 11, 12, 13) and a second end (43) connected to the basic element (33) such that the elastic member (40) pivotally connects the guide wheel (10, 11, 12, 13) to the base member. The crate washing device (1) according to any of the preceding claims, wherein the elastic element (40) is a spring element with a predetermined spring constant of about 0.5 - 1.5 N / cm. Crate washing device (1) according to one of the preceding claims, wherein the contact surface of the guide means (10, 11, 12, 13) is provided with a thermoplastic material or a rubber-like material. The crate washing device (1) according to claim 9, wherein the predetermined positioning force is at least about 10 N. A method for transporting a crate (3) into a crate washing device (1), the method comprising the steps of: inserting a crate (3) into a crate washing device (1) in a conveying direction T along a conveying surface C with a bottom along a conveying surface C and side walls extending in an upward direction, touching the side walls of the crate (3) in a lateral position by a first and a second lateral guide means (10, 11, 12, 13) on the side walls, wherein the first and second lateral guide means (10, 11, 12, 13) each comprise a rotating element that provides a contact surface for exerting a predetermined positioning force against side walls of the crate (3). The method of claim 12, wherein the rotating element comprises a guide wheel (10, 11, 12, 13) rotatably mounted about a wheel rotation axis perpendicular to the transport direction T. A method according to claim 13, wherein after connecting the side walls of the crate (3), the guide wheels (10, 11, 12, 13) assist in transporting the crate (3) to a successive station in the transport direction T . A method according to any one of claims 12-14, wherein while touching the side walls of the crate (3) by the first and second lateral guide means (10, 11, 12, 13), a washing liquid is sprayed against the crate under a pressure higher than 60 bar, preferably higher than 10 bar, and most preferably higher than 110 bar in a direction that is transverse to the conveying surface C.