Pressure washer and a method of providing a super-heated jet of water

Abstract

Some pressure washers include units for introduction of detergents and other chemicals into the water stream; however, it is desirable to obtain sterilized cleaning water without them, such that use in, for instance, food preparation processes can be implemented. With a sufficiently high temperature super-heated water stream, all process equipment, including pipework, that comes into contact with sterile process materials, can be cleaned, de-greased and sterilized both with the spray jet using water alone whilst not contributing endotoxins, microbial contamination or particles. Merely raising the temperature of water in a conventional pressure washer could cause components to fail, if they were not designed to operate at such high temperatures. In the present invention, the pump (25) supplies a relatively low volume of water at a relatively high pressure to the boiler (13), allowing the boiler (13) to heat that volume of water to a relatively high temperature. In contrast, if a higher volume of water were desired over a given time period, the pump would have to supply it at a comparatively lower pressure (which is undesirable) and/or the boiler would only be able to heat it to a comparatively lower temperature over that same time period (which is also undesirable). Increased working temperatures on a hose (3) will reduce its maximum working pressure; however, by using a PTFE hose as in the present invention, the maximum working pressure at 170 degrees may be up to 17 MPa.

Claims

1. A pressure washer, for providing a super-heated jet of water, the pressure washer comprising: a water pump configured to provide at most 20 litres of water per minute at greater than 15 MPa to an output thereof; a boiler arranged to receive pressurised water from the output of the water pump, the boiler configured to heat the pressurised water with a power of at least 75 kW to a temperature of at least 155 degrees centigrade; a hose for conveying the super-heated pressurised water from the boiler, wherein the hose comprises a PTFE lining; and a nozzle connected to the hose and configured to produce a shaped liquid spray jet of super-heated water.

2. The pressure washer of claim 1, wherein the pump is configured to provide at most 9.5 litres of water per minute.

3. The pressure washer of claim 1, wherein the pump is configured to provide water at a pressure of at least 17 MPa.

4. The pressure washer of claim 1, wherein the boiler is configured to heat the pressurised water with a power of at least 90 kW.

5. The pressure washer of claim 1, wherein the boiler is configured to heat the pressurised water to a temperature of at least 170 degrees centigrade.

6. The pressure washer of claim 1, further comprising an electrical generator, and an engine configured to drive the pump and the electrical generator.

7. The pressure washer of claim 6, wherein the electrical generator is configured to generate 24 V DC electricity.

8. The pressure washer of claim 7, wherein the boiler is configured to operate with the 24 V DC electricity supplied by the electrical generator.

9. A method of providing a super-heated jet of water, the method comprising the steps of: providing a pressure washer according to claim 1; providing at most 20 litres of water per minute at greater than 15 MPa; heating the pressurised water with a power of at least 75 kW to a temperature of at least 155 degrees centigrade; conveying the super-heated pressurised water to a nozzle; and producing a shaped liquid spray jet of super-heated water.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The above and other characteristics, features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. This description is given for the sake of example only, without limiting the scope of the invention. The reference FIGURES quoted below refer to the attached drawings.

(2) FIG. 1 is schematic representation of the present invention.

DETAILED DESCRIPTION

(3) The present invention will be described with respect to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. Each drawing may not include all of the features of the invention and therefore should not necessarily be considered to be an embodiment of the invention. In the drawings, the size of some of the elements may be exaggerated and not drawn to scale for illustrative purposes. The dimensions and the relative dimensions do not correspond to actual reductions to practice of the invention.

(4) Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequence, either temporally, spatially, in ranking or in any other manner. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that operation is capable in other sequences than described or illustrated herein.

(5) Moreover, the terms top, bottom, over, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that operation is capable in other orientations than described or illustrated herein.

(6) It is to be noticed that the term comprising, used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It is thus to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression a device comprising means A and B should not be limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B.

(7) Similarly, it is to be noticed that the term connected, used in the description, should not be interpreted as being restricted to direct connections only. Thus, the scope of the expression a device A connected to a device B should not be limited to devices or systems wherein an output of device A is directly connected to an input of device B. It means that there exists a path between an output of A and an input of B which may be a path including other devices or means. Connected may mean that two or more elements are either in direct physical or electrical contact, or that two or more elements are not in direct contact with each other but yet still co-operate or interact with each other. For instance, wireless connectivity is contemplated.

(8) Reference throughout this specification to an embodiment or an aspect means that a particular feature, structure or characteristic described in connection with the embodiment or aspect is included in at least one embodiment or aspect of the present invention. Thus, appearances of the phrases in one embodiment, in an embodiment, or in an aspect in various places throughout this specification are not necessarily all referring to the same embodiment or aspect, but may refer to different embodiments or aspects. Furthermore, the particular features, structures or characteristics of any embodiment or aspect of the invention may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments or aspects.

(9) Similarly, it should be appreciated that in the description various features of the invention are sometimes grouped together in a single embodiment, FIGURE, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Moreover, the description of any individual drawing or aspect should not necessarily be considered to be an embodiment of the invention. Rather, as the following claims reflect, inventive aspects lie in fewer than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.

(10) Furthermore, while some embodiments described herein include some features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form yet further embodiments, as will be understood by those skilled in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

(11) In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practised without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

(12) In the discussion of the invention, unless stated to the contrary, the disclosure of alternative values for the upper or lower limit of the permitted range of a parameter, coupled with an indication that one of said values is more highly preferred than the other, is to be construed as an implied statement that each intermediate value of said parameter, lying between the more preferred and the less preferred of said alternatives, is itself preferred to said less preferred value and also to each value lying between said less preferred value and said intermediate value.

(13) The use of the term at least one may mean only one in certain circumstances.

(14) The principles of the invention will now be described by a detailed description of at least one drawing relating to exemplary features of the invention. It is clear that other arrangements can be configured according to the knowledge of persons skilled in the art without departing from the underlying concept or technical teaching of the invention, the invention being limited only by the terms of the appended claims.

(15) FIG. 1 is schematic representation of a pressure washer for providing a super-heated jet of water from a nozzle 1, supplied by a hose 3. The pressure washer comprises a main unit composed of a frame 5 mounted on wheels 7. The frame 5 is provided with a handle 9 for effecting manual movement of the frame 5 and caster wheels 11 on an upper portion of the frame 5 to assist users in moving the pressure washer up slopes and/or steps. The frame 5 includes a boiler 13 therein, controlled via temperature controller 15 and supplied with fuel 17 from jerry can 19 via pickup 21. The boiler 13 heats water within a heat exchanger 23 before it is past to the hose 3 and thence to nozzle 1. The jerry can is supplied with a handle 24, and may optionally be attached to the frame 5.

(16) Water 25 from reservoir 26 is supplied to the heat exchanger 23 via pump 27, operated by a pump controller 28. The pump 27 is housed within a further frame 29, which also includes a generator 31; specifically, an engine 33, gearbox 35 and electrical generator 37. The generator 31 drives the pump 27 via gearbox 35, and additionally drives the electrical generator 37, which supplies direct current electricity to the temperature controller 15, and optionally the pump controller 28. In alternative embodiments, the pump controller 28 is merely a set of manual controls. The frame is supplied with a carry handle 39, and may optionally be attached to the frame 5.