GB2289505A - Siphon device - Google Patents

Abstract

A siphon device for removing liquid from a container comprises a siphon tube 2 having a first downwardly extending limb 3 for inserting into the liquid, and a second downwardly extending limb 5 which in use is disposed externally of the container and to which a tap or valve 6 is secured. The tap or valve has an outlet to which a siphon initiating means 7 is connected, the siphon initiating means comprising a chamber having a restriction therein defining a venturi, a liquid inlet communicating with the tap or valve, and an air inlet 15 for connection to a source of compressed gas. The arrangement is such that passing a jet of compressed air through the air inlet and thence through the venturi draws the liquid through the siphon tube and tap to initiate a siphoning action. <IMAGE>

Description

SIPHON DEVICE The invention relates to a siphon device for removing liquid from a container such as a drum. More particularly, the invention relates to a siphon device for removing solvents such as paint thinning solvents from a drum in a controlled manner.

Organic solvents, such as those used as paint thinners, are typically supplied in metal drums having a threaded cap closure on their upper surface. Because of the positioning of the opening, dispensing liquid from the drum can present a problem and existing methods for dispensing liquid from solvent drums tend to be somewhat wasteful of solvent, or clumsy to operate, or both. For example, pump action devices are known which are inserted into the liquid and enable the solvent to be pumped out of the drum. However, as the liquid level falls, and the weight of the drum is thus reduced, there is a tendency for the drum and pump arrangement to become destabilised and pumping is made more difficult.

Another known device consists of a siphon tube inserted into the drum, the siphon tube having an external downwardly extending limb with a tap attached to the lower end thereof. On the downstream side of the tap is provided a removable bellows arrangement, the purpose of which is to create a partial vacuum within the siphon tube in order to draw liquid along the tube and initiate the siphoning mechanism. However, this arrangement is somewhat clumsy and the bellows mechanism needs to be removed once the siphon action has started.

Thus, there remains a need for a simple and effective means of dispensing liquid such as solvent from a drum and which can be used in the workshop with a minimum of fuss and waste.

It has now been found that by providing a venturi device, which can be driven by a compressed air source found in any workshop, it is possible to provide a siphonic mechanism for dispensing liquid from a drum in which the siphonic action can be initiated in a very rapid, and easy manner.

In a first aspect therefore, the invention provides a siphon device for removing liquid from a container, the siphon device comprising a siphon tube having a first downwardly extending limb for inserting into the liquid, and a second downwardly extending limb which in use is disposed externally of the container and to which a tap or valve is secured, the tap or valve having an outlet to which a siphon initiating means is connected, the siphon initiating means comprising a chamber having a restriction therein defining a venturi, a liquid inlet communicating with the tap or valve, and an air inlet for connection to a source of compressed gas, the arrangement being such that passing a jet of compressed air through the air inlet and thence through the venturi draws the liquid through the siphon tube and tap to initiate a siphoning action.

In another aspect, the invention provides a combination of a siphon device as herein before defined, and a container containing a liquid such as an organic solvent. The container is typically a solvent drum having an opening in an upper surface thereof.

The chamber preferably has an enlarged bore portion and, downstream thereof, a reduced bore portion, the air inlet opening into the enlarged bore portion, and the liquid inlet opening into the reduced bore portion.

Preferably the liquid inlet takes the form of a pipe extending through the enlarged bore region and into the reduced bore region, the radially outer wall of the pipe and the radially inner wall of the reduced bore region together defining the venturi.

The siphon device is preferably provided with means for securing it to the container, or to a holder for the container. For example, the holder may take the form of a tray into which the container is placed, the securing means being defined by a clip for clipping over a wall of the tray.

Alternatively, the securing means may take the form of means for directly connecting the siphon device to the surface of the container.

The tap or valve connected to the second downwardly extending limb of the siphon tube is preferably a ball valve.

In a further aspect, the invention provides a method of dispensing liquid from a container, the method comprising providing a siphon tube having a first downwardly extending limb and, connected thereto, a second downwardly extending limb fitted with a tap and, connected to a downstream outlet of the tap, a siphon initiating means as hereinbefore defined, inserting the first downwardly extending limb into the container such that it extends into and below the surface cf the iiquid, passing a jet of compressed air through the air inlet of the said siphon initiating means, to create a region of reduced pressure within said means, thereby to draw liquid through the siphon tube to initiate the siphoning action.

The invention also contemplates the siphon initiating means per se.

The invention will now be illustrated, but not limited, by reference to the accompanying drawings, of which: Figure 1 is a side sectional elevation of a solvent drum fitted with a siphon mechanism according to one embodiment of the inventIon; and Figure 2 is a sectional elevation through the siphon initiating means illustrated in Figure 1.

Referring now to the drawings, Figure 1 illustrates a drum D containing a liquid solvent L, which typically is an organic solvent, and in particular is a solvent used for thinning paint. The drum D is provided with a screw threaded neck N in conventional fashion, to which is normally secured a threaded tap (not shown). The drum D is mounted on a support surface S, which may be for example a shelf.

The drum D is fitted with a siphon device according to one embodiment of the present invention. The siphon device 1 comprises a siphon tube 2 having a first downwardly extending portion 3 which in use is inserted into the container such that the lower end of the limb 3 opens out below the level of the liquid L in the container. Downwardly extending portion 3 is connected via horizontally extending portion 4 to second downwardly extending limb 5, to the lower end of which is attached a ball valve and tap assembly 6. Ball valve and tap assembly 6 is of conventional type, and the construction of the ball valve and tap arrangement 6 need not be described in further detail here. Valve 6 has an internal thread which engages an external thread on the lower end of limb 5.Secured to the downstream end of tap 6 is the siphon initiating means 7, the construction of which will be described in more detail below.

The siphon tube 2 is provided with an annular flange 8 located near the upper end of downwardly extending limb 3. Flange 8 serves as a stop for threaded cap 9 which sits about the limb 3. In use, threaded cap 9 is secured to the threaded neck N of the container, in order to minimise evaporation of solvent through the opening in the container.

Towards the lower end of downwardly extending limb 5 is located a joggled clip 10 which serves to engage an upstanding side wall of tray 11 in which the container D is mounted. Clip 10 secures the siphon device in place, anchoring the siphon tube against undesirable movement.

The construction of the siphon initiating means is illustrated in more detail in Figure 2 which is a side sectional elevation of the said initiating means. The siphon initiating means comprises a barrel portion 12 which is internally threaded and is provided with a side opening 13 extending into a side arm 14, which is secured to the barrel portion by means of a soldered joint. Side arm 14 is encircled by rubber sleeve 15 to which an end of a compressed air source may be connected.

A spigot fitting 16 having an external thread 18 is secured within the upstream end of barrel portion 12. Spigot 16 has extending therefrom a pipe 19, which in this embodiment is first "sweated" into the bore of spigot 16 and is then secured in place by means of a soldered union 20. However, the pipe 19 could alternatively be formed integrally with the spigot fitting 16. Spigot 16 is also provided at its upstream end with an external thread 17 which engages a corresponding internal thread on the ball valve and tap arrangement 6.

At the downstream end of the barrel, a spigot fitting 21 is secured therein by means of a thread 22 on the radial outer surface of the spigot.

Spigot 21 is also provided with an external thread 2 on a downstream end thereof in order to allow its connection to, e.g, a supply line.

Downstream spigot portion 21 has a through bore 23 into which the pipe 19 of the upstream spigot portion 16 extends. The radially outer wall 26 of pipe 19, and the radially inner wall of the spigot portion 21 together define a constriction 25 in the form of an annular passage, which functions as a venturi.

Merely by way of example, the barrel 12 may be formed by machining hexagonal brass rod, and the upstream and downstream spigot portions may also be formed by machining brass rod. It will be appreciated however that alternative materials, such as stainless steel, could equally be used, and the barrel and spigot could be formed by casting rather than machining.

In use, tap 6 is moved to the open position, and a compressed airline of the type commonly found in workshops, particularly paint spray shops, is connected to the rubber sleeve 15. A jet of compressed air, typically at a pressure in excess of 80 p.s.i., and more usually about 140 p.s.i. or more, is then directed through the opening 13. The compressed air passes from the enlarged diameter portion 27 of the chamber through the constriction 25 and then past the end of pipe 19. The resulting venturi effect leads to reduced pressure within the siphon tube which has the effect of drawing solvent along the siphon tube 2, through the tap 6 and out through pipe 19 into a suitable receptacle (not shown). Once the continuous column of liquid has been established in the siphon tube, the tap may then be closed.Thereafter, the tap may be turned on and off at will, liquid being dispensed from the siphon tube by means of a siphonic action.

The advantages of the siphon initiating mechanism of the present invention are several. Thus, in paint spray shops, it is usual for a paint spray operative to carry a compressed air gun as a means of clearing out the nozzle of a paint spray head following use. Given the ubiquitous nature of such compressed air nozzles, it is an easy matter for the operative to initiate the siphon mechanism by means of a quick blast of compressed air from his compressed air gun. Initiating the siphonic mechanism takes only a matter of seconds, and there is no need to remove the siphoning means from the tap once the siphon action has started, although of course it can readily be removed should this be so desired.

Once the continuous column of liquid has been established in the siphon, the liquid can then be dispensed as and when required until the container is virtually empty, without the need for further activation of the siphon.

A further advantage of the siphon mechanism of the present invention is its simplicity of construction, in that it is formed from a minimal number of parts which can readily be manufactured using simple engineering tools.

Although the invention has been illustrated by reference to the dispensing of solvent from solvent drums, the siphon device of the invention may equally be used in combination with other types of liquid container.

It will readily be appreciated that numerous alterations and modifications could be made to the embodiments illustrated, without departing from the principles underlying this invention, and all such modifications and alterations are within the scope of this Application.

Claims (8)

1. A siphon device for removing liquid from a container, the siphon device comprising a siphon tube having a first downwardly extending limb for inserting into the liquid, and a second downwardly extending limb which in use is disposed externally of the container and to which a tap or valve is secured, the tap or valve having an outlet to which a siphon initiating means is connected, the siphon initiating means comprising a chamber having a restriction therein defining a venturi, a liquid inlet communicating with the tap or valve, and an air inlet for connection to a source of compressed gas, the arrangement being such that passing a jet of compressed air through the air inlet and thence through the venturi draws the liquid through the siphon tube and tap to initiate a siphoning action.

2. A device as claimed in claim 1 wherein the chamber has an enlarged bore portion and, downstream thereof, a reduced bore portion, the air inlet opening into the enlarged bore portion, and the liquid inlet opening into the reduced bore portion.

3. A device as claimed in claim 1 or claim 2 wherein the liquid inlet takes the form of a pipe extending through the enlarged bore region and into the reduced bore region, the radially outer wall of the pipe and the radially inner wall of the reduced bore region together defining the venturi.

4. A device as claimed in any one of claims 1 to 3 further comprising a container for holding an organic solvent, means being provided to secure the device to the container or to a holder for the container.

5. A device as claimed in claim 4 wherein the holder takes the form of a tray into which the container is placed, the securing means being defined by a clip for clipping over a wall of the tray.

6. A device as claimed in any one of the preceding claims wherein the tap or valve connected to the second downwardly extending limb of the siphon tube is a ball valve.

7. A method of dispensing liquid from a container, the method comprising providing a siphon tube having a first downwardly extending limb and, connected thereto, a second downwardly extending limb fitted with a tap and, connected to a downstream outlet of the tap, a siphon initiating means as hereinbefore defined, inserting the first downwardly extending limb into the container such that it extends into and below the surface of the liquid, passing a jet of compressed air through the air inlet of the said siphon initiating means, to create a region of reduced pressure within said means, thereby to draw liquid through the siphon tube to initiate the siphoning action.

8. A siphon device substantially as herein described and as described with reference to Figures 1 and 2 of the accompanying drawings.