GB2280700A

GB2280700A - Liquid storage container for dispensing system

Info

Publication number: GB2280700A
Application number: GB9316338A
Authority: GB
Inventors: Alan Marshall; Chris Dennis Davies
Original assignee: WR Grace and Co Conn; WR Grace and Co
Current assignee: WR Grace and Co Conn; WR Grace and Co
Priority date: 1993-08-06
Filing date: 1993-08-06
Publication date: 1995-02-08
Anticipated expiration: 2013-08-06
Also published as: GB9316338D0; GB2280700B

Abstract

A storage vessel for liquids which can be filled from its top end, without the risk of foaming of the incoming liquid, has the inlet aperture (16) arranged so that liquid entering through the inlet aperture will impinge on a wall of the vessel along which it will flow as it descends to meet the rest of a body of liquid within the vessel. The wall may for example be the internal wall of a cylindrical body of the vessel (Figure 3), or a shelf (104) on which the liquid is guided circumferentially round the vessel from a high point just below a panel (108) where the inlet aperture is formed. <IMAGE>

Description

LIOUID STORAGE CONTAINER FOR DISPENSING SYSTEN The present invention relates to a liquid storage container for a liquid dispensing system, and in particular to a container which is designed to prevent foaming of a liquid being fed into the container.

In a liquid storage system it has been proposed that the consumer have a static storage vessel for liquids such as aggressive chemicals, and that the storage vessel be re-stocked by a distributor, using a vehicle with a transport container conveying the chemical in question.

In order to allow such a storage vessel to be recharged using the minimum of effort, the vessel should have the following properties: (i) it should be filled from the top to allow the entering liquid to be discharged freely from a constant height thereby ensuring that the back pressure will be substantially constant (which would not be the case if the liquid were to be driven into the container from below and to have to overcome a varying hydraulic static pressure head as the liquid level builds up in the storage vessel); (ii) the vessel should be equipped with a vent for allowing displacement of air as the volume of liquid in the container increases during the filling operation (thereby avoiding back pressure of trapped air in the vessel); and (iii) there should be an overflow to allow the liquid to escape in the event of inadvertent overfilling.

The overflow will of course be relatively small in dimensions so as to avoid dangerous splashes of corrosive chemicals, but the cross-sectional area of the air vent should be substantial. There is then a risk of the liquid escaping through the air vent in the event of foaming as it is poured into the container.

It is an object of the present invention to avoid such foaming in a container which is equipped with a sub stantial air vent.

Accordingly, the present invention provides a storage vessel for a liquid dispensing system, comprising a container body of generally cylindrical form, a vent opening in said container body, an inlet opening for entering liquid at a first end of said storage vessel, and means for ensuring entering liquid flows down a wall of the storage vessel towards the second end substantially without free-fall on to the surface of liquid already in the vessel, thereby avoiding foaming.

More specifically, in one embodiment of the present invention the inlet to said vessel is arranged for connection to an end of an inlet hose which extends generally tangentially of the cylindrical body of the vessel, and the means for ensuring the liquid runs down a wall surface of the storage vessel comprises a support for the hose end so as to be projected parallel to and close to the internal surface of said cylindrical body whereby, during filling of the container with liquid entering the container with its own momentum, the liquid contacts the internal wall surface of the cylindrical body generally tangentially and runs down the wall surface of said cylindrical body. In practice the liquid flow may be deliberately angled downwardly slightly so that the divergent jet of incoming liquid cannot spray on to the ceiling of the tank.

Such an embodiment offers the advantage that freefall of the entering liquid stream onto the interface of the liquid already in the storage vessel is prevented, but at the same time adequate flow of liquid to augment the supply already in the storage vessel is made possible by the action of the liquid flowing down and along the wall of the storage vessel, rather than splashing down in freefall.

This considerably reduces the foaming action in the vessel.

Directing the liquid with a horizontal component of movement, and directing it substantially tangentially, ensures that there will be an absolute minimum of splash back into the free gas space within the container. In other words, the liquid will be partly descending at the point of impact with the walls, and partly moving peripherally and the curvature of the wall against which it impacts substantially tangentially is such that the liquid will be carried progressively around an arcuate path with smooth adhesion between the liquid and the cylindrical wall. Even in the event of diminution of flow rate of the incoming liquid, there will still be a tendency for the liquid to adhere to the adjacent wall as a result of the tangential inlet flow direction.

In a second embodiment of the present invention the storage vessel includes a liquid inlet in a horizontal panel of the storage reservoir for gravity feed from a transfer container thereabove, and said means for ensuring liquid flow passes downwardly of the storage vessel along a wall surface thereof comprises a shelf inclined with respect to a transverse plane through said cylindrical body and arranged to extend from a part located directly below said inlet aperture sloping downwardly away from the inlet aperture in a direction around the circumference of the cylindrical body.

With such an arrangement, the limited freefall of the liquid from the lower end of an inlet fitment of the transfer container superposed above the storage vessel, onto the inclined shelf, is so limited in vertical extent that there will be no substantial splashing but from there on the liquid will flow down the shelf, or spill over the edge of the shelf and then run down the cylindrical wall of the storage vessel below the shelf, in either event ensuring that there will be no substantial freefall of liquid onto the air/liquid interface in the container at which foaming could possibly have occurred.

With both the above embodiments of storage vessel, the vessel may include a generally transversely extending beak portion which is positioned near the top of the vessel and which has in its underside an overflow opening in the event of overfilling.

Such a beak has the advantage that it is possible to suspend a fume scrubber under the beak, in communication with the overflow opening, and hence allowing any gaseous phase of the composition within the storage vessel to pass out through the abovementioned overflow opening in the underside of the beak and to be treated by contact with the cleansing medium in the fume scrubber. Having the fume scrubber suspended under the beak provides a particularly convenient and compact way of locating the fume scrubber within the confines of a bund by which the storage vessel may be surrounded.

The vessel may also be provided with a substantial air vent in its top wall, but this may be blocked off when the abovementioned fume scrubber is being used.

In order that the present invention may more readily be understood the following description is given, merely by way of example, with reference to the accompanying drawings, in which: FIGURE 1 is a side elevational view of a first embodiment of storage vessel in accordance with the present invention; FIGURE 2 is a front elevational view (i.e. seen from the right hand side of Figure 1) of the same storage container, but shown partially in section; FIGURE 3 is a top plan view of the storage vessel of Figures 1 and 2 with the frontal direction illustrated by arrow 1; FIGURE 4 is an underneath plan view of the storage vessel of Figures 1 to 3; FIGURE 5 is a front elevational view of a second embodiment of storage vessel in accordance with the present invention; FIGURE 6 is a side elevational view of the vessel of Figure 5 seen from the right;; FIGURE 7 is a rear elevational view of the storage vessel of Figures 5 and 6; FIGURE 8 is a top plan view of the storage vessel of Figures 5, 6 and 7; and FIGURE 9 is an underneath plan view of the storage vessel shown in Figures 5 to 8.

Figure 1 shows a storage vessel generally referenced 1, having at its top an inlet aperture 2 for a chemical to be stored therein. The chemical for which the container is designed may be one which is corrosive or otherwise aggressive and which should not be allowed to come into contact freely with either the environment or an operator; it is envisaged that, in the event of a mishap, the surrounding area outside the storage vessel 1 will be contained within a bund such as is described and claimed in our copending Patent Applications Nos. 9316343.4 (Folio N.66575) and 9316339.2 (Folio No.66693).

At its left hand side, at the top, the vessel 1 has a beak 4 in which an overflow aperture 5 is formed in the underside (see Figure 4).

In the top wall of the vessel 1 is an upstanding rim 3 which may define an air vent to be covered by a cap which nevertheless allows substantial escape of air from within the vessel 1 as it is being filled. However, it is envisaged that for some chemicals there will be a fume scrubber suspended from the beak 4, above the floor of the bund, fed with gases from the overflow 5. In that event there will be a closure cap fitted on the rim 3 to seal off the vent aperture. Such a fume scrubber may be filled with a substance able to absorb the gas, or may use running water to convert the gas to a liquid phase for carrying away from the bunded area.

At the bottom of the vessel 1 there can be seen in Figure 1 a concavity 6 which is one of three (visible as 6, 7 and 8 in Figure 4) which serve to stand the vessel 1 securely on three ledges of a support base such as the base of a bund referred to above.

The side view of Figure 2 illustrates the concavity 7, but also shows the concavity 8 in a sectional detail which illustrates the thin wall structure of the vessel comprising a substantially cylindrical sidewall 9, a flat central base 10, and a top panel 11, and a radially inner sloping panel 12 of the concavity 8. Although not shown in Figure 2, the top panel 11 of the concavity 8 includes a mounting lug in the form of a downwardly projecting pin 15 which is visible in Figure 4 along with the corresponding pins 13 and 14 of the concavities 6 and 7, respectively.

As shown in Figure 3, the inlet aperture 2 of Figure 1 is formed on a tangentially extending projection 16 of the storage vessel so that the entering liquid follows the direction of the arrows which illustrate that the substantially horizontally projected liquid soon strikes the inside surface of the cylindrical sidewall 9 of the vessel 1 and then circulates around the axis of the vessel 1 in contact with the wall so that the liquid does not splash down on to the air/liquid interface on the surface level of liquid already in the vessel 1 but simply runs down the sidewall to merge with the existing liquid without splashing, but more importantly without foaming.

The foaming-preventing action of the vessel of Figures 1 to 4 is particularly advantageous where there is some momentum of the entering fluid (other than simply filling the container under gravity), which will convey the fluid far enough in the horizontal direction to strike the inner wall.

Given that the storage reservoir 1 of Figures 1 to 4 is intended to receive an inlet in which the incoming liquid has its own momentum (for example by being positively pumped or by virtue of having been entrained by an air pressure differential), the means for ensuring that the liquid passes down the storage vessel in contact with a vertical wall of the reservoir is defined by the tangential ly extending projection 16 which has at one end the inlet opening 2 shown in Figure 1 and which is arranged such that the axis of a hose connected to the inlet opening 2 will project chordally into the vessel in a direction which extends perpendicular to a diametral plane represented by the diameter D in Figure 3. This projects the liquid in a direction where its own momentum carries it into contact with the internal sidewall 9 of the cylindrical body of the storage vessel.

The same storage vessel has its overflow aperture 5 arranged in that diametral plane, but in the underside of the beak 4 defining a radially outward projection at the top of the storage vessel.

The discharge of liquid from the vessel 1 is by way of the centrally positioned drain hole 17 in the floor panel 10 shown in the underneath plan view of Figure 4. The storage vessel 1 is constructed by injection moulding of a plastic material such as polypropylene or medium density polyethylene or high density polyethylene and the inlet hole 2 will be formed during the moulding operation and will allow fastening of a hose end fitting to the tangentially extending projection 16 (Figure 3) to connect the storage vessel 1 to a transfer pump for transferring the liquid from a transport container which has been brought on a delivery vehicle.

An alternative embodiment of the storage vessel is shown in Figures 5 to 9, and is particularly suitable for filling by a gravity feed action. For example, with a smaller storage vessel of the design shown in Figures 5 to 9 it may be contemplated to deliver fresh supplies of the liquid such as a corrosive chemical to the storage vessel using a sealed box of the liquid (having a plastic or other liquid-tight and corrosion-resistant inner lining) so that inversion of the box on the top surface of the storage vessel and connection of a male fitment 110 (Fig. 7) of the box with a female inlet fitment 111 of the storage vessel (secured on transfer aperture 109 in the recess 108) allows the contained liquid to fall under gravity into the storage vessel.Again it is desired that this free-fall action of the liquid from the lower end of the storage vessel female fitment 111 should not result in foaming of the incoming liquid.

The male fitment 110 of the box has a bayonet coupling head and a shut-off valve to provide for a dry break connection between the box and the storage vessel whose female fitment 111 also has a shut-off valve for dry break connection. The dry break connection facility also allows rinsing of the male fitment of the box.

The reservoir 101 shown in Figure 5 comprises a generally cylindrical body 102 having around its upper portion an outwardly extending part 103 which defines a ledge internally of the container, shown in dotted lines at 104 in Figure 6. The underneath of the same ledge 104 is visible at external surface 105 in Figure 7. The ledge 104 is just below the lower end of a female fitment 111 when located in the aperture 109.

As with the storage vessel of Figures 1 to 4, the vessel shown in Figures 5 to 9 has an air vent defined by an upstanding rim 106 visible in Figures 5, 6 and 8. As with the embodiment of Figures 1 to 4, this vent rim will be covered by a cap which clips in place and therefore prevents any direct access to the liquid within the storage vessel but nevertheless provides substantial air venting capacity to allow air within the storage vessel to be vented as the falling of liquid in the vessel increases during filling.

The storage vessel of Figures 5 to 9 has in its top wall a recess 107 to receive the bayonet projections of the male fitment 110 of the transport container when the transport container (box) is not in use and is standing on the storage vessel.

Equally, as with the embodiment of Figures 1 to 4, the vent may be sealed for use with a fume scrubber (not shown).

When the male delivery fitment of the box is attached to female fitment 111 in the transfer aperture 109 in the recess 108 transfer begins and the liquid from the transport box falls a short distance (from the lower end of the female fitment 111 adjacent the highest point of the shelf 104) on to the shelf 104 at its highest point (Figure 6) and is then allowed to run down the inclined shelf 104 on the right hand side of the vessel as viewed in Figure 6 to the left hand side.The shelf extends helically during this progression from right to left in Figure 6 but it also decreases in radial extent so that at the lowest point of the shelf corresponding to the point marked at 110 in Figure 6 the shelf is virtually non-existent and by then the liquid will have run over the edge of the shelf and down the sidewall of the cylindrical body 102 to join the liquid already in the storage vessel without splashing or foaming.

The upper part of the female fitment 111 and the lower end of the bayonet coupling male fitment 110 are accommodated in the recess 108, and the open side of the recess (at the right hand side in Figures 6 and 8) allows manipulation of a control lever 112 of the female fitment.

The underneath plan view of Figure 9 shows clearly a beak 111 corresponding to the beak 4 in Figure 1 and shows also the overflow hole 112 formed in the underside of that beak. Furthermore, the underneath plan view of Figure 9 illustrates concavities 113, 114 and 115 corresponding to the concavities 6, 7 and 8 of Figure 4 and also the mounting lugs 116, 117 and 118 corresponding to the lugs 13, 14 and 15 of Figure 4. Finally, the storage vessel of Figure 9 also includes a central drain hole 119 to receive a delivery hose which may be connected to a delivery pump such as a dosing pump for chemical plant using the chemical from within the storage vessel 101.

In the embodiment of Figures 5 to 9 it is the inclined shelf 104 that ensures that the incoming liquid flows gently down the wall of the vessel, after only a very short freefall, in order to avoid foaming.

The storage vessel 101 of Figures 5 to 9 is suitable for smaller volumes such as from 50 to 100 litres, and the vessel 1 of Figures 1 to 4 is more suitable for vessels of over 100 litres in capacity, for example a 250 litre size.

Claims

1. A storage vessel for a liquid dispensing system, comprising a container body of generally cylindrical form, a vent opening in said container body, an inlet opening for entering liquid at a first end of said storage vessel, and means for ensuring entering liquid flows down a wall of the storage vessel towards the second end substantially without free-fall on to the surface of liquid already in the vessel, thereby avoiding foaming.

2. A storage vessel according to claim 1, wherein the inlet to said vessel is arranged for connection to an end of an inlet conduit which extends generally tangentially of the cylindrical body of the vessel, and wherein the means for ensuring the liquid runs down a wall surface of the storage vessel comprises a support for the conduit end so as to be projected parallel to and close to the internal surface of said cylindrical body whereby during filling of the container with liquid entering the container with its own momentum, the liquid contacts the internal wall surface of the cylindrical body tangentially and runs down the wall surface of said cylindrical body.

3. A storage vessel according to claim 2, wherein said support for the conduit end comprises an external tangentially extending projection of the cylindrical body having an axis which will coincide with the axis of said conduit end and which extends chordally close to the internal surface of said cylindrical body.

4. A storage vessel according to claim 3, and including an overflow aperture formed in the underside of a radially outward projection from said first end of said cylindrical body, and wherein the diametral plane of the cylindrical body which intersects said overflow aperture extends perpendicular to said chordally extending axis of the tangentially extending projection defining a support for the conduit end.

5. A storage vessel according to any one of claims 2 to 4, wherein said vent opening is formed centrally of a flat roof of the cylindrical body.

6. A storage vessel according to claim 1, and including a liquid inlet in a horizontal panel of the storage reservoir for gravity feed from a transfer container thereabove, wherein said means for ensuring liquid flow passes downwardly of the storage vessel along a wall surface thereof comprises a shelf inclined with respect to a transverse plane through said cylindrical body and arranged to extend sloping downwardly from a part located directly below said inlet aperture, away from the inlet aperture in a direction around the circumference of the cylindrical body.

7. A storage vessel according to claim 6, wherein said shelf extends round substantially the full circumference of said cylindrical body from one end of a diameter of symmetry of the body adjacent to which the shelf is closer to said first end of said storage vessel, to the other end of said diameter where the shelf is closest to the second end of said storage vessel, whereby liquid entering the storage vessel in a direction parallel to the axis of said cylindrical body lands on said shelf and runs along the shelf while passing towards said second end of the storage vessel.

8. A storage vessel according to claim 7, wherein said shelf diminishes in radial extent between the part located directly beneath said inlet aperture and a part closest to the said opposite end of a cylindrical body.

9. A storage vessel according to any one of claims 6 to 8, and including an inlet fitment secured in said inlet aperture and having its lower end adjacent said part of the shelf.

10. A storage vessel according to any one of claims 1 to 9, wherein said vent aperture is at least partially formed in a transversely extending projection at the top of said cylindrical body and wherein there is an overflow aperture formed in the underside of said projection, disposed outside the continuation of the cylinder defining said cylindrical body.

11. A storage vessel according to any one of claims 6 to 10, wherein said inlet aperture is formed in a recessed portion of the storage vessel, on a panel below the first end of the storage vessel but substantially level with a roof of the cylindrical body.

12. A storage vessel according to any one of the preceding claims, and including a central drainhole in the second end of said storage vessel, and including a plurality of concavities formed equiangularly around said drain hole to locate the storage vessel on an array of equiangularly arranged suitably formed ledges therefor.

13. A storage vessel substantially as hereinbefore described with reference to, and as illustrated in, Figures 1 to 4 of the accompanying drawings.

14. A storage vessel substantially as hereinbefore described with reference to, and as illustrated in, Figures 5 to 9 of the accompanying drawings.

Amendments to the claims have been filed as follows

1. A storage vessel for a liquid dispensing system, comprising a container body having a side wall of generally cylindrical form; a vent opening in said container body; an inlet opening for entering liquid at a first end of said storage vessel; and means for ensuring entering liquid flows down the side wall of the storage vessel towards the second end with a component of motion orbiting round the axis of symmetry of said generally cylindrical side wall substantially without free-fall on to the surface of liquid already in the vessel, thereby avoiding foaming.

2. A storage vessel according to claim 1, wherein the inlet to said vessel is arranged for connection to an end of an inlet conduit which extends generally tangentially of the cylindrical side wall of the vessel, and wherein the means for ensuring the liquid runs down the side wall of the storage vessel comprises a support for the conduit end so as to be projected parallel to and close to the internal surface of said generally cylindrical side wall whereby, during filling of the container with liquid entering the container with its own momentum, the liquid contacts the internal wall surface of the container body tangentially and runs down the surface of said generally cylindrical side wall.

3. A storage vessel according to claim 2, wherein said support for the conduit end comprises an external tangentially extending projection of the container body having an axis which will coincide with the axis of said conduit end and which extends chordally close to the internal surface of said generally cylindrical side wall.

4. A storage vessel according to claim 3, and including an overflow aperture formed in the underside of a radially outward projection from said first end of said container body, and wherein the diametral plane of the container body which intersects said overflow aperture extends perpendicular to said chordally extending axis of the tangentially extending projection defining a support for the conduit end.

5. A storage vessel according to any one of claims 2 to 4, wherein said vent opening is formed centrally of a flat roof of the container body.

6. A storage vessel according to claim 1, and including a liquid inlet in a horizontal panel of the storage reservoir for gravity feed from a transfer container thereabove, wherein said means for ensuring liquid flow passes downwardly of the storage vessel along the side wall thereof comprises a shelf integral with said side wall and inclined with respect to a transverse plane through said generally cylindrical side wall and arranged to extend sloping downwardly from a part located directly below said inlet aperture, away from the inlet aperture in a direction around the generally cylindrical side wall.

7. A storage vessel according to claim 6, wherein said shelf extends round substantially the full circumference of said cylindrical side wall from one end of a diameter of symmetry of the generally cylindrical side wall adjacent to which the shelf is closer to said first end of said storage vessel, to the other end of said diameter where the shelf is closest to the second end of said storage vessel, whereby liquid entering the storage vessel in a direction parallel to the axis of symmetry of said generally cylindrical side wall lands on said shelf and runs along the shelf while passing towards said second end of the storage vessel.

8. A storage vessel according to claim 7, wherein said shelf diminishes in radial extent between the part located directly beneath said inlet aperture and a part closest to the said opposite end of the container body.

10. A storage vessel according to any one of claims 1 formed in a transversely extending projection at the top of said container body and wherein there is an overflow aperture formed in the underside of said projection, disposed outside the continuation of the cylinder defining said container body.

11. A storage vessel according to any one of claims 6 to 10, wherein said inlet aperture is formed in a recessed portion of the storage vessel, on a panel below the first end of the storage vessel but substantially level with a roof of the container body.