GB2256029A

GB2256029A - Dosing valve for foaming agent

Info

Publication number: GB2256029A
Application number: GB9209704A
Authority: GB
Inventors: Hermann Gohringer
Original assignee: Total Walther Feuerschutz GmbH; Total Feuerschutz GmbH
Current assignee: Total Walther Feuerschutz GmbH; Total Feuerschutz GmbH
Priority date: 1991-05-08
Filing date: 1992-05-06
Publication date: 1992-11-25
Also published as: SE9201344D0; SE9201344L; GB9209704D0; FR2676175A1; DE4115101A1

Description

2 2 5 6 lu -2 9 DOSING VALVE FOR FOAMING AGENT The invention relates to a

dosing valve for a foaming agent, wetting agent or the like for fire extinguishing devices in stationary or mobile units or 5 in fire extinguishing vehicles.

Such devices are used in fire extinguishing units for admixing a foaming agent and a quenching agent e.g. water. For this purpose the admixer is controlled such that even with a varying rate of flow, an equal percentage of admixture of foaming agent is constantly supplied to the quenching agent.

In stationary devices electronically controlled mixers have been used. In such a case the admixing function is carried out by a normal premixer, which functions according to the principle of a water jet pump. This admixing apparatus is built into a bypass of the water pump, between the pump output and pump input.

Specially manufactured dosing valves are also used for dosing the foaming agent. These valves are complicated in their manufacture.

The underlying object of the invention is to provide a dosing valve of the type having a ball valve with connection pieces on both the inlet and outlet side, which valve can be inserted into an extinguishing agent conduit and is provided with a manual adjusting device for the ball. In particular to provide such a valve having a nominal width adaptable for several ranges of flow and at the same time being an adequate facility for dosing.

According to the present invention there is provided a dosing valve capable of insertion into a fire extinguishing agent conduit, which dosing valve comprises a housing, an inlet and an outlet, a ball provided with a through passage disposed between the inlet and outlet, a first connection piece provided at t the inlet, a second connection piece provided at the outlet and means for adjusting the position of the through-passage of the ball relative to the inlet and outlet, wherein the valve further comprises a dosing plate provided with one or more openings, in which the or each opening is able to be placed in fluid communication with the through-passage of the ball.

With such a dosing valve the through-flow can be controlled by the position of the through-passage of the ball relative to the opening or openings of the dosing plate. Where the through-passage corresponds fully, i.e. is aligned fully, with the whole opening or all of the openings maximum flow is possible. As the degree of correspondence between the through-passage and opening or openings is reduced the amount of through-flow possible is also reduced. A commercial ball cock can be used, which is more economical than a specially manufactured valve. Quite apart from the fact that a single size of valve can be used for several ranges of flow, due to the dosing plate an accurate dosing of the required rate of flow of foaming agent can be achieved. In this connection a large angle of adjustment, when adjusting the ball, assists accurate dosing.

The dosing plate can be provided with any shaped opening, e.g. the cross-sectional shape of the opening can be varied to suit the dosing requirements. The cross-sectional shape of the opening or openings and its or their position on the dosing plate affect or affects the change of flow obtained as the position of the through- passage of the ball is altered with respect to that opening or openings. For a single opening, where the cross-sectional shape is regular or of constant dimensions, as the degree of correspondence between the through-passage and opening is increased the through-flow will be linearly increased. In this 4 Y' case the rate of flow, depending on the position of the through-passage of the ball, is progressively, i.e. linearly, adjustable from e.g. 0 to 100% of the admixture of foaming agent. Where the dosing plate is provided with a series of openings of identical crosssectional dimensions which are progressively one after the other brought into correspondence with the throughpassage, e.g. four such openings are progressively placed in fluid communication with the through-passage, then the rate of flow can be divided easily into four settings, namely 25, 50, 75 and 100%. If separate openings of varying cross-sectional dimensions or a single opening having an irregular cross-section, e.g. a triangular cross-sectioned opening, are provided, then the rates of flow can be varied non-linearly by the simplest means.

The dosing plate is preferably associated with, e.g. inserted into, one of the connection pieces. The dosing plate may be situated on the inlet or the outlet side of the ball. The dosing plate may be clamped into position by one of the connection pieces and it may be adapted to assist in its retention in position. The connection pieces may be provided with threads for the connection of the dosing valve to a fire extinguishing agent conduit in which it is inserted.

Further inventive features are described more closely in the following and represented in the drawings in which:

Figure 1 shows a section through a dosing valve according to the present invention having a dosing plate; Figure 2 shows a plan view of the valve of Figure 1; Figure 3 shows a section according to Line A-B in Figure 1; Figures 4 to 7 show different positions of the valve of Figure 1; and Figures 8 to 11 show different embodiments of dosing plates.

The dosing valve 1 comprises a valve housing 2 having a through-bore 3 and left and right connection pieces 4, 5 with internal threads 6 and 7. In the central region of the housing 2 the bore 3 is enlarged so much that a ball 8 can be fitted with corresponding ring bearings. The ball 8 which is provided with a through-passage 9 is connected to a ball-ended spindle 10, which is able to be adjusted by means of a hand lever 11. The position of the ball can thereby be adjusted. In the exemplary embodiment shown a dosing plate 12 is inserted into one of the threaded connection plates 5 and is clamped by way of a seal 28 of an extinguishing agent conduit 27. For this purpose the valve housing 2 is provided with a recess or shoulder 13, against which an outer projection 14 of the dosing plate 12 rests. The dosing plate 12 is provided with a series of separate openings 17 to 20.

The extinguishing agent conduit 27 is screwed with an external thread 27a into the internal thread of the threaded connection piece 5. Screwed into the thread 6 of the other threaded connection piece 4 there is an extinguishing agent conduit 26.

On the hand lever 11 there is attached an indicator 29, to which is allocated a scale plate 30 with a scale 31. The scale plate 30 is connected firmly to the valve housing 2. On the scale plate 30 there is located a stop 32, which cooperates with two stops 33 and 34 connected to the hand lever 29 so as to limit the travel possible of that lever.

Figure 3 shows a section A-B of Figure 1, wherein for simplification only the dosing plate 12 is represented. The inner face 16 of the dosing plate 12 is adapted in shape, i.e. correspondsto the outer face 1 of the ball 8. For technical manufacturing reasons the inner face 16 of the dosing plate 12 also has a shape approximating to that of the sphere, as is represented in Figure 7.

In use the fluid flows through the dosing device 1. The amount of flow allowed is governed by the position of the through-passage 9 of the ball 8 relative to the bore 3 of the valve housing 2. Where the through- passage 9 of the ball 8 is positioned so as to correspond with all of the openings of the dosing plate 12 (or with the entire cross-section of a single opening of the dosing plate 12) maximum flow is possible. Reduction in the maximum flow is obtained by varying the number of openings of the dosing plate 12 with which the throughpassage 9 of the ball 8 is in fluid communication (or by varying the amount of area of the cross-section of a single opening which so corresponds).

Figures 4 to 7 show different positions of the through-passage 9 of the ball 8 relative to the bore 3 of the valve housing 2 and the openings 17 to 20 of the dosing plate 12. In the position shown in Figure 4 all of the openings 17 to 20 are fully acted upon, i.e. all are in fluid communication with the through-passage 9 of the ball 8..so that a 100% mixing rate is produced. In the position shown in Figure 5 only three of the openings are acted upon and in the position shown in Figure 6 only two openings, so that a 75 or 50 mixing rate is produced. In the position shown in Figure 7 the valve is closed and accordingly a mixing rate which is-equal to nil is achieved.

In Figures 8 to 11 four dosing plates 12 are represented, which have in each case different shaped openings 15 and 17 to 25. In the embodiment shown in Figure 9 the opening has a cross-section in the form of a continuous slot 15 of substantially constant width, -6 with which a progressive, i.e. linear, adjustment of the mixing rate is possible. With the plurality of similar openings 17 to 20 of the embodiment of Figure 8, which each have circular cross-sections of substantially identical dimensions, accurately defined mixing rates can be regulated. With the plurality of differing openings 21 to 24 of the embodiment of Figure 11, which vary in the size of their cross-sectional areas, i.e. their cross-sections are circles of varying 10 diameter, or the opening 25 of the embodiment of Figure 10, whose cross-sectional width varies as its crosssectional shape tapers from one end to the other, the mixing rates can be varied correspondingly.

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Claims

1. A dosing valve capable of insertion into a fire extinguishing agent conduit, which dosing valve comprises a housing, an inlet and an outlet, a ball provided with a through-passage disposed between the inlet and outlet, a first connection piece provided at the inlet, a second connection piece provided at the outlet and means for adjusting the position of the through-passage of the ball relative to the inlet and outlet, wherein the valve further comprises a dosing plate provided with one or more openings in which the or each opening is able to be placed in fluid communication with the through-passage of the ball.

2. A dosing valve according to claim 1, wherein the dosing plate is provided with a single opening having a cross- sectional shape that is regular or of constant dimensions.

3. A dosing valve according to claim 1, wherein the dosing plate is provided with a single opening having an irregular cross-sectional shape.

4. A dosing valve according to claim 1, wherein the dosing plate is provided with a series of openings of identical cross-sectional shape and dimension.

5. A dosing valve according to claim 1, wherein the dosing plate is provided with a series of openings which vary in cross-sectional shape or dimension.

6. A dosing valve according to any preceding claim, wherein the dosing plate is situated on the inlet side of the ball. 30

7. A dosing valve according to any preceding claim, wherein at least one of the connection pieces is threaded.

8. A dosing valve according to any preceding claim, wherein the dosing plate is inserted into one of the connection pieces.

9. A dosing valve according to claim 8, wherein 1 a seal is provided between the dosing plate and the connection piece.

10. A device according to claim 8, wherein the extinguishing agent conduit is threaded for attachment 5 to the connection piece.

11. A dosing valve according to any preceding claim, wherein the dosing plate is provided with an outer projection which cooperates with a recess provided in the valve housing.

12. A dosing valve according to any preceding claim, wherein the surface of the face of the dosing plate which faces the ball is adapted, i.e. corresponds, to the outer surface of the ball.

13. A dosing valve according to any preceding claim, wherein for manual adjustment of the ball a hand lever is provided, which hand lever is capable of acting on the ball and has an indicator, to which is allocated a scale plate secured to the valve housing.

14. A dosing valve according to claim 13, wherein the scale plate has a stop and the hand lever has two corresponding stops.

15. A dosing device according to any preceding claim, wherein the dosing plate is formed from a plastics material. 25

16. A dosing valve substantially as hereinbefore described with reference to and as illustrated in Figures 1 to 8, Figure 9, Figure 10 or Figure 11 of the accompanying drawings.

17. A dosing plate for a dosing valve substantially as hereinbefore described with reference to and as illustrated in figures 8, 9, 10 or 11 of the accompanying drawings.

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