WO1992006790A1

WO1992006790A1 - Nozzle pipe for a hose

Info

Publication number: WO1992006790A1
Application number: PCT/DK1991/000311
Authority: WO
Inventors: Jarl Flemming Larsen; Flemming Larsen
Original assignee: Aqua Flow Aps
Priority date: 1990-10-22
Filing date: 1991-10-14
Publication date: 1992-04-30
Also published as: DK253890D0

Abstract

A nozzle pipe comprising a liquid pipe (1), an air pipe (2), and a casing (3). The air pipe (1) allows air under atmospheric pressure to be sucked into the liquid which is conveyed in the liquid pipe (2). The form and placing of the air pipe in the clear of the liquid pipe result in that a partial vacuum is established round the aperture in the air pipe in the liquid pipe thereby causing air to be sucked into the liquid. This results in an increase in pressure in the liquid which thus leaves the orifice (7) of the liquid pipe with a greater velocity than if air has not been supplied to the liquid. To avoid that foreign bodies block the outer aperture of the air pipe the nozzle pipe furthermore comprises a casing (3) which covers the aperture of the air pipe but which still allows air to be admitted to the air pipe.

Description

NOZZLE PIPE FOR A HOSE. Background of the Invention.

The present invention relates to a nozzle pipe for discharging a li¬ quid being under pressure, which nozzle comprises a liquid pipe and one or more air pipe/pipes.

The nozzle pipe according to the invention is a device which is mount¬ ed at the end of a hose in which a liquid is conveyed. This liquid, preferably water, is under pressure from the ordinary water supply, a compressor, or a pressure tank. Primarily, the nozzle pipe is used for flushing surfaces or materials which are to be cleaned and where a flushing and cleaning effect is desirable.

The inner diameter of the nozzle pipe has the same diameter or a some- what smaller diameter than the liquid pipe which leads to the nozzle pipe thereby allowing the fluid pressure prevailing in the hose to be maintained or increased a little in the nozzle pipe.

US patent No. 1,389,593 discloses nozzle pipes which generate an air intake for producing an encircling air cushion around the liquid flow when this leaves the pipe. In this nozzle pipe the liquid flow and the annular air cushion formed around it are distinctly separated.

US patent No. 4,801,090 discloses a nozzle for mounting on a hose. this nozzle has a reduction in the diameter which increases the pres¬ sure in the liquid, and simultaneously the nozzle is provided with orifices through which compressed air is blown into the liquid flowing through the nozzle. Due to the form of the nozzle it is necessary to admit compressed air. This is disadvantageous as it then becomes ne- cessary to have supplementary inlets in the form of secondary hoses to the primary liquid hose/nozzle.

It is the object of the present invention to provide a nozzle pipe which remedies the above-mentioned drawbacks and which only needs to be connected to a water supply pipe and which produces an improved flushing effect by admitting air to the nozzle pipe.

According to the present invention this is obtained with a nozzle pipe of the type mentioned above which is characterized in that the air pipe/pipes extends/extend from the outer periphery of the liquid pipe where the air pipe/pipes is/are in connection with the ambient air under atmospheric pressure through the wall of the liquid pipe and into the clear of the liquid pipe so that part of the clear is covered by the air pipe/pipes.

The nozzle pipe according to the invention is characterized by obtain- ing an increase in pressure by air supply and thus a higher flushing and cleaning effect without an increase in water consumption.

The increase in pressure which arises is caused by the partial vacuum formed by the location of the air pipe in the liquid pipe as the fluid at increased velocity is compelled to flow round that part of the air pipe which extends into the liquid pipe. This partial vacuum results in that air is sucked into the liquid which flows in the liquid pipe. This air has a certain volume which absorbs a part of the volume which before was entirely constituted by liquid. The volume which the liquid has at its disposal is thus reduced. As the liquid is substantially incompressible a greater amount of fluid consisting of liquid contain- ing air bubbles has to be discharged through the orifice of the liquid pipe per unit of time. This corresponds to increasing the pressure at the orifice of the liquid pipe.

According to an advantageous embodiment the nozzle pipe over a part or over its entire length is provided with an outer casing having a some¬ what larger inner diameter than the outer diameter of the liquid pipe for providing a certain distance between the casing and the liquid pipe, which casing covers the outer orifice of the air pipe. As a re¬ sult a handle-like nozzle pipe is obtained where the air intake is established freely through the annular slot between the casing and the liquid pipe.

Brief Description of the Drawing.

The invention will now be further explained with reference to the ac- companying drawing, which

shows a sectional view through a nozzle pipe according to the inven¬ tion. The drawing illustrates the nozzle pipe comprising a liquid pipe 1, and air pipe 2 and a casing 3. The air pipe extends from the outer side 4 of the liquid pipe through the latter and through the inside 5 of the liquid pipe and a distance into the clear of the liquid pipe having the diameter d,. In the embodiment shown the air pipe extends half into the clear of the liquid pipe, but it can extend arbitrarily into the clear.

At the end 6 intended for connection to the liquid hose the nozzle pipe is provided with connection means and fastening means which pro¬ vide a fastening of the nozzle pipe to the hose. The connection means can either be a simple connection piece which is inserted into the hose and is fastened with clamps or the like. It can also be quick- clutch devices which permit an easy and quick attachment and discon- nection of the nozzle pipe to the hose so that the pipe can be used alternately on several different hoses. Connection means and fastening means of the above-mentioned type are not shown as the form of these can be very individual depending on the requirements, desires and spe¬ cific use, and such devices are beyond the scope of the invention as stated in the claims.

Besides, the nozzle pipe can be provided with various forms of handles and grips so that the pipe becomes easier to guide at high fluid pres¬ sure and at high muzzle velocity for the liquid at the orifice 7 of the liquid pipe.

In the embodiment shown the air pipe 2 is a straight pipe which is fastened to the wall of the liquid pipe. The liquid pipe 1 will advan¬ tageously be made of plastic and the air pipe 2 of metal and the fas- tening can be made by an interference fit of the air pipe in the wall of the liquid pipe. The air pipe forms an acute angle with the longi- tudinaly axis of the nozzle pipe and at this position a partial vacuum is established which ensures that air is led into the liquid without the use of pressure increasing arrangements for precompressing the air.

Beyond the embodiment shown the air pipe may have many other forms: either straight, as shown, or curved, or a pipe with one or more bend/ bends, as long as a partial vacuum is established which results in that air being under atmospheric pressure is sucked into the liquid. In the embodiment shown the aperture of the clear of the air pipe is perpendicular to the longitudinal axis of the nozzle pipe, but other angle positions of the aperture will also be possible in order to ob- tain an optimum air intake into the liquid.

In an alternative embodiment the nozzle pipe is provided with several air pipes to obtain a more even distribution of the air in the liquid.

As previously mentioned the air pipe 2 is advantageously made of me¬ tal, but where particularly corrosive liquids are used in connection with the nozzle pipe it may be desirable that the air pipe is made of other materials which do not erode or corrode.

Apart from being a separate pipe which is fastened to the wall of the liquid pipe the air pipe can be made by preparing the wall of the li¬ quid pipe in such a way that a hole is formed in the wall. At the same time the wall material which is prepared when forming this hole will form a projecting part in the clear of the liquid pipe immediately before the hole formed. Said projecting part will then establish the partial vacuum which sucks air in through the hole.

3 A casing 3 is fastened on the greater outer diameter d of the liquid pipe. This casing extends a distance beyond the smaller of the outer 2 diameters d of the liquid pipe and at least so far that the aperture of the air pipe to the atmosphere is covered. This casing substantial¬ ly reduces the risk of foreign bodies becoming fixed in or round the air pipe and its aperture thereby blocking the air current through the pipe at the same time as the air supply to the outer aperture of the pipe is maintained.

The table below states specific values for the inner and the outer diameter of the liquid pipe for the air pipe used thereto. The values are used in connection with a nozzle pipe where the air pipe consists of a straight pipe which forms an acute angle in relation to the lon¬ gitudinal axis of the nozzle pipe, and where the air pipe extends less than half into the clear of the liquid pipe. Inner diameter d 16 14 12 10 10 of the liquid pipe

Outer diameter of the air pipe 6 5 5 4 2 2 2

All measures are in millimetres.

Primarily the nozzle pipe is used in industries which require cleaning of large surfaces, such as the shipping and fishing industries and the building industry. However, the nozzle pipe can very well be used for all other purposes where water jets or other liquid jets are used, such as fire extinguishing or watering or fertilization crops.

The nozzle pipe can also be used in connection with other equipments or in other structures where a flushing is necessary. Then the pipe is built into the structure in question as the flushing element.

Claims

C L A I S:

1. A nozzle pipe for discharging a liquid being under pressure, which nozzle comprises a liquid pipe and one or more air pipe/pipes, c h a r a c t e r i z e d in that the air pipe/pipes extends/extend from the outer periphery of the liquid pipe where the air pipe/pipes is/are in connection with the ambient air under atmospheric pressure through the wall of the liquid pipe and into the clear of the liquid pipe so that part of the clear is covered by the air pipe/pipes.

2. A nozzle pipe according to claim 1, c h a r a c t e r i z e d in that the air pipe extends half or less into the clear of the liquid pipe.

3. A nozzle pipe according to claims 1 and 2, c h a r a c t e r i ¬ z e d in that the orifice of the air pipe in the clear of the liquid pipe faces the orifice of the liquid pipe.

4. A nozzle pipe according to any of the preceding claims, c h a r - a c t e r i z e d in that the air pipe consists of a pipe having a smaller outer diameter than the inner diameter of the liquid pipe.

5. A nozzle pipe according to any of the preceding claims, c h a r - a c t e r i z e d in that the air pipe consists of a straight pipe, a curved pipe or a pipe having one or more bend/bends.

6. A nozzle pipe according to any of the preceding claims, c h a r ¬ a c t e r i z e d in that the air pipe is a straight pipe, and that the angle between the central axis of the air pipe and the central axis of the liquid pipe is from approximately 15° to approximately 75°, and preferably from approximately 30° to approximately 60".

7. A nozzle pipe according to any of the preceding claims, c h a - a c t e r i z e d in that the air pipe is made of metal, and that the liquid pipe is made of plastic.

8. A nozzle pipe according to any of the preceding claims, c h a r ¬ a c t e r ]^' z e d in that the ratio of the outer diameter of the air pipe and the inner diameter of the liquid pipe is from approximately 1:5 to approximately 1:2, preferably from approximately 1:4 to appro¬ ximately 1:3.

9. A nozzle pipe according to any of the preceding claims, c h a r - a c t e r i z e d in that the air pipe is located at a distance from the orifice of the liquid pipe, which distance is approximately 3-6 times the inner diameter (dp) of the liquid pipe, and preferably ap¬ proximately 4 times the inner diameter of the liquid pipe.

10. A nozzle pipe according to any of the preceding claims, c h a r - a c t e r i z e d in that the nozzle pipe over a part or over its en¬ tire length is provided with a casing having a somewhat larger inner diameter than the outer diameter of the liquid pipe for providing a certain distance between the casing and the liquid pipe, which casing covers the outer orifice of the air pipe.