Field of the Invention

The present invention relates to the area of industrial washing machines, in particular washing machines where containers or crates are conveyed through a washing machine on a continuous basis.

Background of the Invention

Washing machines of this type are typically used for washing of items like containers or crates used for packaging goods, such as food items. Containers are reused and in order to maintain a high level of safety a proper cleaning of the containers is necessary.

A number of approaches are known in the art of industrial washing machines. A washing machine of this type typically comprises a top part and a bottom part and a conveyor system for conveying items to be washed, e.g. crates, through the washing machine at a certain speed determined by the conveyor. The washing is performed by washing equipment, normally spraying bars or the like. The conveyor and the washing equipment are normally supported on an intermediate support construction, also known as a drain deck. The drain deck may serve as a first separator of residue washed off the item conveyed through the machine or may serve as a waterway leading the washing water to drains and filter for preparing the reuse of the hot liquid.

Such machines are operated continuously and as a consequence of the use for remov- ing dirt and residue from the items fed into the machine, the machine itself will contain a significant amount of the material washed off the items. This will obviously require frequent cleaning of the machine

In particular in larger industrial washing machines of this type, which may have a length of 10 m or more, the access to the inner part, in particular to the bottom part, takes place through hatches provided in the side area of the bottom part. The access is limited and due to this the cleaning is difficult. This may lead to improper cleaning and subsequently to a decreased hygienic standard of the washed items. When the items washed do not satisfy the requirements to the hygienic standard, e.g. in the food industry a risk of contamination of the food products will be the result.

Object of the Invention

It is an object of the invention to provide a washing machine that is easier to clean and maintain.

Description of the Invention

The objective is achieved through a washing machine comprising a lower part and an upper part, creating a tunnel with open passageways at each end and a conveyor for continuous transfer of goods to be washed inside the tunnel, where between the lower part and the upper part a drain deck is provided, where the upper part may be lifted to create access to the space between the drain deck and the upper part and where further the drain deck may be lifted to create access to the lower part.

By providing a possibility for lifting the drain deck in such type washing machine, an improved access to the lower part of the washing machine is created and the cleaning and maintenance operations will be both easier to carry out and improved in quality, with the further result that operational cost is reduced and hygienic standards are in- creased.

In many instances a conveyor is provided on the drain deck, and advantageously the conveyor is adapted to be lifted together with the drain deck. In order to do this the conveyor will be adapted for the upward movement, e.g. by being separated from conveyor parts outside the washing machine or by being flexible in a manner allowing the upward movement

Normally washing equipment in the form of spraying nozzles and supply piping is provided, and advantageously the conveyor provided between the lower and the upper parts as well as the washing equipment is adapted to be lifted together with the drain deck. The conveyor will in this case have the same properties as described above and the piping leading the washing fluid to the nozzles may be a flexible hose or a pivot- able piping arrangement, e.g. comprising several links or being telescopic. In one embodiment the drain deck is adapted to be lifted together with the upper part. A further option is that the drain deck is adapted to be lifted separately after lifting the upper part.

This may be performed through connecting the drain deck to the upper part, using coupling elements and lifting this together with the upper part, or by connecting the drain deck directly to lifting means in order to be lifted. The lifting means are typically actuators provided for lifting the upper part and the drain deck, either together or individually. Other means for lifting are possible options without changing the scope of the invention.

In another aspect of the invention the washing machine comprises a lower part and an upper part, where between the lower part and the upper part a drain deck is provided, where the lower part is manufactured from stainless steel and where the upper part is manufactured from a synthetic material. The stainless steel parts are suitable for welding and connecting pumps, heat exchangers, filters, detergent dosing equipment and water supplies. The synthetic material of the upper part may include certain plastics, reinforced plastics, composites, resins or combinations thereof. The main criteria for this material is its ability to provide a sufficient strength and rigidity while at the same time maintaining a relatively low weight and the ability to resist wash temperatures and detergents while simultaneously having a noise and heat insulating effect in its wall structure. An example of a material compound is vinyl ester.

The invention will be described in more detail in the following description of preferred embodiments, with reference to the drawing, where:

Description of the Drawing

FIG. 1 A-C shows a first embodiment of the washing machine according to the inven- tion in different views;

FIG. 2A-D shows a second embodiment of the washing machine according to the invention in different views;

FIG. 3 A-D shows a third embodiment of the washing machine according to the invention in different views; and FIG. 4A-D shows a fourth embodiment of the washing machine according to the invention in different views.

Detailed Description of the Invention

In the drawing reference is made to the following numbering:

1. Top part

2. Tank/bottom part

3. Drain deck

4. Lifting devices

5. Joints

6. Conveyor

7. Spray bars

8. Crate

FIG. 1-4 each show a crate washing system comprising a top part 1, a bottom/tank part 2, a drain deck 3 and lifting devices 4. Resting on the drain deck a conveyor 6 is provided as well as spray bars 7 constituting the washing equipment for washing a crate 8 that has been returned after use. Joints 5 are provided for connecting the drain deck 3 and the top part 1.

FIG. 1 A shows with its wash water tank reservoir 2 below and top 1 above, those two parts being separated by a drain deck 3 carrying the conveyor 6 and the washing equipment in the form of spray bars 7. When the top 1 and the bottom tank part are closed they form a crate washing tunnel. FIG. IB shows the washing system with its top elevated for easy open access, inspection, cleaning and maintenance of the tunnel interior and FIG. 1C shows the system with both its top 1 and drain deck 3 elevated for easy open access, inspection, cleaning and maintenance of the tank 2 interior. Compared to systems having only multiple doors and cleaning hatches integrated in tunnel top and tank side walls, the present invention provides easier and better access for cleaning and inspection, mainly because such doors and hatches will only offer limited access and reduced visibility. Besides that the present invention will provide for smoother surface structures of the inside walls further facilitating easier and better cleaning and hence increasing hygiene level to obtain improved crate and food safety. FIG. 2 A-D shows a crate washing system with a steel top 1 and a steel tank 2, symbolized by the sharp edges of the construction. FIG. 1A shows the system when closed for operation. FIG. IB shows the system with its top elevated. Fig. 1C shows the system with its top 1 and drain deck 3 elevated and finally FIG. ID shows the sys- tern with its top 1 and drain deck 3 separately elevated.

FIG. 3 A-D show a crate wash system with a synthetic top and a steel tank, symbolized by the rounded shape and the sharp edges, respectively. FIG. 1A shows the system when closed for operation. FIG. IB shows the system with its top 1 elevated. FIG. 1C shows the system with its top 1 and drain deck 3 elevated and FIG. ID shows the system with its top 1 and drain deck 3 separately elevated. As shown in FIG. 3 A-D the crate wash system is differentiated from other washing system in having a new combination of a steel tank 2 and a synthetic top 1. The synthetic top will provide for reduced cost and further it is noise and heat insulating. A low weight will provide for particularly easy elevation and access, such top also having the possibility of achieving high degree of outside/room light penetration to support internal machine visibility, and such tubular top with rounded walls having smooth in- and outside surfaces without corners or bends, all together accommodating easier and better cleaning inside and around the wash system increasing hygiene level towards improved crate and food safety and will as such also be useful and advantageous without having a movable drain deck.

FIG. 4 A-D shows a crate washing system with a synthetic top 1 and a synthetic tank 2 again symbolized by the rounded shape of the respective elements. In FIG. 1 the washing system is shown as closed for operation. In FIG. IB the system is shown with its top 1 elevated. In FIG. 1C the system is shown with its top 1 and drain deck 3 elevated and in FIG. ID with its top 1 and drain deck 3 separately elevated.

In all embodiments the lifting devices 4 are preferably actuators capable of lifting both the top and the drain deck. It is however a possibility that separate lifting devices are provided for lifting the two elements separately. Other types of lifting devices may be provided without falling outside the scope of the invention. The conveyor 6 as well as the washing equipment 7 will be lifted together with the drain deck 3. In order to achieve this, the conveyor needs to be established as a separate conveyor part for the washing machine or at least be separable from further conveyor elements outside the washing machine.

The washing equipment comprises supply piping or hoses that need to provide for certain flexibility in order to allow the lifting together with the drain deck. Normally a flexible hose may be sufficient, but pivotable piping arrangements may be an option as well as telescopic piping.