GB2099319A - Liquid metering and dispensing apparatus - Google Patents

Abstract

A liquid metering and dispensing apparatus comprises an automatically filling and discharging supply tank (1) for a liquid to be treated with a liquid reagent, a reservoir (5) for the reagent mounted above the supply tank, a cup (6) mounted in the reservoir responsive to movement of a float 9 in the supply tank for vertical reciprocal movement relative to the reservoir between a filling position below the level of liquid reagent contained therein and a discharge position above the level, and a solid plunger (7) mounted above said cup in a position to engage the cup in its discharge position thereby displacing a given quantity of reagent from the cup onto the supply tank. <IMAGE>

Description

SPECIFICATION Liquid metering and dispensing apparatus This invention relates to liquid metering apparatus of a type which dispenses a measured quantity of a first liquid, e.g. a hydrochloride solution, into a second liquid, e.g. a water supply.

In many parts of the world there is a need for a simple and robust apparatus for metering small, but controlled amounts of a water-purifying agent, e.g.

aqueous hydrochlorite solution, into a water supply, and more particularly an apparatus that can be installed in remote locations and left to operate for long periods of time without servicing and without requiring an external source of power, other than the water supply itself. Such apparatuses are required, for example, by small communities and individual homes or farms which are not connected to a mains water supply but are dependent upon a local water supply, e.g. a local well or spring.

According to the present invention such a liquid metering and dispensing apparatus is provided comprising: a) a supplytamkfor a liquid to be treated with a liquid reagent; b) means for automatically cyclically filling and discharging the supply tank with a controlled quantity of liquid to be treated; c) a reservoirforthe reagent mounted above said supply tank; d) a cup mounted in said reservoir for vertical reciprocal movement relative thereto between a filling position below the level of liquid reagent contained therein and a discharge position above said level; e) a float positioned in the supply tank, and operatively connected to said cup whereby the cyclically rising and falling liquid level therein reciprocates said cup between said filling and discharge positions;; f) a solid plunger mounted above said cup in a position to engage in said cup in its discharge position thereby displacing a given quantity of reagent from the cup; and g) means for collecting the reagent displaced from the cup and delivering it into the supply tank.

In the preferred arrangement, the reagent reservoir is in a fixed position above the supply tank, and the float is directly connected to the cup. In this arrangement the cup is raised to the discharge position and displacement of the reagent therefrom occurs during the filling cycle of the supply tank. To adjust the quantity of reagent displaced from the cup, either the position of the plunger may be vertically adjusted and/or adjustable stops may be provided to limit the upward vertical travel of the cup during the filling cycle of the supply tank.

The means for collecting the displaced reagent, in a preferred embodiment of the invention comprises a pivotally mounted channel which, as the cup is moved relative to the reservoir into its discharge position pivots under gravity into a position below the cup to catch the displaced reagent and deliver it to the supply tank. Preferably the cup has a lip or spout over which the reagent is displaced into the collecting channel.

The means for automatically filling and discharging liquid to be treated to the supply tank comprises, in the preferred embodiment, a connection for continuously feeding the liquid to the supply tank and a siphon mounted in the base of the tank, the siphon acting in known mannerto empty the tank when the liquid therein reaches a predetermined level.

Although the apparatus described herein is primarily intended for water treatment, i.e. for metering and dispersing measured quantities of a liquid reagent, e.g. an aqueous sodium hypochlorite solution, into a crude water supply, it is obvious that the apparatus may be used for a wise variety of other purposes where automatic and controlled metering of one liquid into another is required.

The invention is further described with reference to the accompanying drawings which illustrate in diagrammatic form the operating principles of a preferred embodiment. In the drawings: Fig. 1 is a diagrammatic vertical section through the apparatus of this invention at the beginning of the operating cycle; Fig. 2 is a similar section through the apparatus of this invention at the mid-point of the cycle.

Fig. 3 is a side elevation taken on arrow A of the reagent reservoir.

Referring to the drawings the apparatus comprises a supply tank 1 having an inlet 2, connected to a continuous supply of water to be treated, e.g. a natural spring, and a siphon outlet3 in the bottom which operates automatically in known manner to discharge water from the supply tank when the water reaches a predetermined level. The supply tank therefore fills and empties on the automatic cycle, with a predetermined quantity of water discharged each time. Suitably the outlet 3 will be connected to a stock or storage tank, not shown.

Mounted above the supply tank 1 in a fixed position relative thereto is a reagent reservoir4 having a vertically elongated sump 5 in which a cup 6 is mounted for vertical reciprocal movement therein.

The cup 6 is carried on the central leg 7 of a threelegged bridge member8 mounted for vertical reciprocal movement above the tank 1 and the reservoir 4. The bridge member will, of course, be mounted on suitable guides, not shown, and one or more stops may be provided to limit and/or adjust the vertical travel of the bridge member in either direction.

The bridge member8 is reciprocated in the vertical direction by a float 9 connected to the leg 10 and extending down into the supply tank 1. On the other leg 11 is a pivoted channel member 12 which normally rests under gravity in an inclined position against the external wall of the sump 5.

Mounted directly above the cup 6 and in axial alignment therewith is a downwardly extending fixed plunger 13.

The drawing(s) originally filed was/were informal and the print here reproduced is taken from a later filed formal copy. The reagent reservoir4 is open to atmospheric pressure and, in use, will be charged with a sufficient quantity of reagent, e.g. sodium hypochlorite solu tion, to permit the apparatus to function for a con siderable period of time, e.g. a week or more, with out attention or replenishment.

The function of the apparatus will, now be described. At the beginning of the operating cycle (Fig. 1 ) the water in the supply tank 1 will be at its lowest level, and consequently the bridge member8 will be at its lowest point of travel with the cup 6 immersed below the level of reagent in the reservoir 4. The cup is thus filled with a precise quantity of reagent determined by the dimensions of the cup. In this position also the channel member 12 rests in an inoperative position against the external wall of the sump 5.

As the water level rises in the tank 1, the float 9 rises and carries with it the bridge member until the position shown in Fig. 2 is reached. In this position, the outlet siphon 3 begins to operate to discharge the water from the supply tank. During filling of the supply tank 1 the cup6 full of reagent is lifted clear of the reagent reservoir 4 by the bridge member and is eventually entered by the fixed plunger 13 which operates as a displacement member to displace reagent from the cup 6 through the lip 14. Displaced reagent discharging from the lip 14 is caught by the channel member 12 which by this time has travelled up the external surface of the sump 5 and, once clear of the upper rim of the sump, has pivoted inwardly under gravity to rest against the outer surface of the cup 6 (see Fig. 2) with its upper end positioned immediately below the lip 14.Displaced reagent is thus caught by the channel and directed into the supply tank 1 clear of the reservoir 5. The quantity of reagent displaced from the cup can be varied by adjusting the vertical position of the plunger 13 and/or by adjustment of stops, not shown, to limit the upward travel of the bridge member 8. The depth of penetration of the plunger into the cup, and hence the quantity of liquid displaced, can thus be controlled.

During downward movement of the bridge member 8 following the falling liquid level in the supply tank 1 during the discharge cycle, the cup 6 re-enters the reagent reservoir sump 5 to be refilled with reagent whilst the inclined channel member 12 engages the rim of the sump 5 so as to be moved thereby in an anticlockwise direction back into its original inclined position resting against the outer wall of the sump. At the end of the discharge cycle, the position shown in Fig. 1 is reached and the cycle is ready to be repeated.

As will be apparent, the apparatus described requires no external power source, apart from the water supply, has a minimum of moving parts with bearings or bearing surfaces which are all above liquid levels, so that corrosion problems are minim- ized, and requires only minimal attention in the periodic topping up of the reagent reservoir. Also since the dimensions of the cup and the plunger are known and can be closely controlled, the quantity of reagent dispensed during each cycle is controlled with little or no risk of errors occurring as a result of reagent inadvertently splashing into the supply tank during filling of the cup.

Claims (6)

1. A liquid metering and dispensing apparatus comprising: a) a supplytankfora liquid to be treated with a liquid reagent; b) means for automatically cyclically filling and discharging the supply tank with a controlled quantity of liquid to be treated; c) a reservoirforthe reagent mounted above said supply tank; d) a cup mounted in said reservoir for vertical reciprocal movement relative thereto between a filling position belowthe level of liquid reagent contained therein and a discharge position above said level; e) a float positioned in the supply tank, and operatively connected to said cup whereby the cyclically rising and falling liquid level therein reciprocates said cup between said filling and discharge positions;; f) a solid plunger mounted above said cup in a position to engage in said cup in its discharge position thereby displacing a given quantity of reagent from the cup; and g) means for collecting the reagent displaced from the cup and delivering it into the supply tank.

2. Apparatus according to claim 1, wherein the reagent reservoir is in a fixed position above the supply tank, and the float is directly connected to the cup.

3. Apparatus according to claim 1 or 2, wherein the means for collecting the displaced reagent comprise a pivotally mounted channel which, as the cup is moved relative to the reservoir into its discharge position pivots under gravity into a position below the cup to catch the displaced reagent and deliver it to the supply tank.

4. Apparatus according to claim 3, wherein the cup has a lip or spout over which the reagent is displaced into the collecting channel.

5. Apparatus according to any one of the preceding claims, wherein the means for automatically filling and discharging liquid to be treated to the supply tank comprises a connection for continuously feeding the liquid to the supply tank and a siphon mounted in the base of the tank, the siphon acting to empty the tank when the liquid therein reaches a predetermined level.

6. Apparatus according to claim 1, substantially as hereinbefore described with reference to the accompanying drawings.