GB2097687A - Fluid proportioning apparatus - Google Patents

Abstract

A fluid proportioning apparatus comprises first and second reservoirs (2,4) for fluids to be mixed and a third reservoir below the first and second reservoirs and in which the fluids are mixed. Equal pressure heads are maintained on the liquids in the first and second reservoirs by a conduit (48). The reservoirs discharge into the third reservoir through orifices of predetermined sizes. Means including a valve are provided for normally maintaining equal pressures on the fluids in all three reservoirs; however, if the fluid in the third reservoir rises above a predetermined level the valve may be closed to reduce the fluid flow to the third reservoir. <IMAGE>

Description

SPECIFICATION Fluid proportioning apparatus This invention relates generally to fluid proportioning apparatus, and more particularly to a fluid proportioning apparatus of the type that is particularly suitable for accurately blending heavy brew beer and brewing liquor or for blending soft drink syrup and water.

In fluid proportioning apparatus of the foregoing type it is desirable to provide a pair of reservoirs, one for each fluid, and to pass the fluids through proportioning orifices at like pressures in order to maintain the precise proportions of the fluid in the mix. Generally speaking, columns of fluids are maintained at equal and constant heights above the proportioning orifices in order to maintain a constant outlet pressure at the orifices and resultant precise proportioning. A previously proposed manner of accomplishing the foregoing is to provide a pair of fluid containers which include overflow columns, and wherein pumps are used to maintain the overflow columns in an overflow condition during the operation of the apparatus.The overflow columns are of equal height above the respective orifices so that by maintaining the overflow columns full, the pressures at the discharge orifices at the lower ends of the overflow columns are maintained equal. One such device is disclosed and claimed in U.S. Patent No. 3,237,808. However, the use of pumps and overflow columns increases the cost of the apparatus.

According to the present invention, there is provided a fluid proportioning apparatus for continuously proportioning diverse fluids, comprising a first reservoir for a first fluid, a second reservoir for a second fluid, a third reservoir below said first and second reservoirs, a conduit from each reservoir for conveying fluid by gravity flow from each of said first and second reservoirs to the third reservoir, means for maintaining equal pressures in all three reservoirs, and means interposed in each conduit and having orifices of predetermined sizes and operable in response to said equal pressures for supplying said first and second fluids in predetermined proportions to said third reservoir.

Embodiments of the invention, will now be described by way of example, with reference to the accompanying diagrammatic drawings, in which: Figure lisa diagrammatic layout of a proportioning apparatus in accordance with the present invention and wherein the in-line filter is upstream from one of the supply reservoirs for the constituent fluids; Figure 2 is a modified form of apparatus for use in systems wherein the filter is downstream from the third reservoir; Figure 3 is a further modified form of apparatus with downstream filtering; and Figure 4 is another modified form of apparatus with upstream filtering.

Referring more particularly to Figure 1 there is shown a fluid proportioning apparatus comprising a pair of reservoirs 2, 4 for a first fluid 6 and a seconf fluid 8. The first fluid 6 may be a high gravity beer, heavy brew or soft drink syrup whereas the second fluid 8 may be deoxygenated water. The liquid 6 is supplied from a storage tank 10 through piping 12 to the reservoir 2. In the piping 12 are a filter 14 and valves 16, 18. The valve 16 is controlled by a valve actuator 20 which is controlled, in turn, by a float 24.

This arrangement regulates the flow of liquid to the reservoir 2.

Water is supplied to the reservoir 4 through inlet piping 26 which includes valve 28 controlled by valve actuator 30. The valve actuator 30 is controlled by a float 32, the arrangement being such that the valves 28 closes when the float 32 is raised to a predetermined level. This valve actuator 30 may be of a known pneumatic type such as shown in United States Patent No.3,272,020. Other and conventional valve actuators may be used.

Depending from the first and second reservoirs 2, 4 are conduits 34,36. These conduits 34,36 discharge into a mixing header 38 at which the fluids 6, 8 are mixed in predetermined proportions. This mixing header forms part of a third or receiving reservoir 45. For this purpose the conduits 34,36 have lower sections 40, 42 which are formed with orifices. In the section 42 the orifice is fixed in size whereas in the section 40 the orifice may be adjusted to provide selected cross-sectional openings. In this way the size of the orifice in the section 40 may be changed relative to the size of the orifice 42 so as to correspondingly vary the proportions of the mixed fluids. The discharges through the respective orifices pass into the mixing header 38 for blending the two liquids priorto being discharged through conduit 44 into the lower portion of the reservoir 45.

The header 38 is maintained in a flooded condition. For this purpose a balance line 46 provides communication between the top of the header 38 and a balance pipe 48. This pipe 48 provides gas and pressure-equalizing communication between the reservoirs 2,4 above the liquids therein. The balance line 46 bleeds off the gasses from the header 38 to ensure a flooded condition therein. Here, a second balance line 50 provides pressure communication between the reservoirs 2, 4, 45 above the liquid levels therein. This balance line 50 contains a valve 52. When the valve 52 is closed, pressure builds up in the reservoir 45; this pressure soon becomes sufficient to halt the inflow of fluid from the mixing header 38. Consequently, all fluid flow in Lhe proportioner is soon stopped when the valve 52 is closed.

When the valve 52 is open, the proportioner will operate.

The blended mix from the reservoir 45 may be withdrawn through conduit 54 by a pump 56 for delivery through piping 58 to storage tank 60. A float-controlled valve 62 operates responsive tno a valve controller 64 which, in turn, responds to the position of a float 66 in the reservoir 45. Thus, when the level of the float 66 drops below a predetermined point the valve 62 closes to reduce the outflow from the reservoir 45.

In the conduit 44 is a control valve 68 which is preferably a slide valve actuated by a diaphragm that is moved by air pressure. The slide valve may be of the type disclosed in U.S. Patent Application Serial No. 151,393 filed May 19,1980. Othertypesofslide valves may be used, however, and the valve in the aforesaid application is by way of example and not of limitation. Suffice it to say that the valve slide 70 moves under control of a diaphragm within a diaphragm housing 72. A greater or lesser amount of cross-sectional area will be present to the flowing mixture in the conduit 44 as the diaphragm moves the valve slide 70.

In the reservoir 2 there is a float 74 that operates a valve actuator 76, preferably of the pneumatic type disclosed in United States Patent No.3,272,020, referred to previously. Floats 32 and 74 are set to keep the liquid levels the same in reservoirs 2 and 4.

The valve controller 76 provides an air supply over air line 78 in a known manner to apply air pressure to the diaphragm of the control valve 68. The arrangement is such that as the float 74 drops, upon reduction of the liquid level in the reservoir 2, an increase of air pressure will be supplied to the valve 68. This increase in air pressure causes the valve slide 70 to move and decrease the orifice size, thereby to decrease the flow of mixed fluid from the header 38 into the reservoir 45. Likewise, as the float 74 rises, a decreased air pressure will be applied to the diaphragm of the valve 68 to move the valve slide 70 such that the orifice size progressively increases, thereby increasing the flow of the mixed fluids.Because the valve 68 controlles the flow of the mixture, and the proportions between the two fluids remain constant for any particular setting of the valve 68, the fluid level in reservoirwill remain equalized with the level in reservoir 2, 4 thereby maintaining the same pressure head on the orifice at section 40 and at 42.

The filter 14 may be of a diatomaceous earth. In due time the filter 14 will become clogged and reduce the flow rate or supply of heavy brew to the reservoir 2. When this occurs the reservoir 2 will tend to be "starved" for liquid, thereby reducing the level of the float 74. However, the flow through the valve 68 is simply reduced while the proportions of the fluid remain unchanged. Normal operation of the apparatus results in a gradual clogging of the filter and similarly gradual reduction in the level of the float 74. Thus, the operation of the slide valve 68 is effective throughout the useful operating cycle of the filter 14.

Reference may now be had to Figure 2 in which like reference numerals appearing in Figure 1 refer to like parts in Figure 2. However, in the apparatus of Figure 2. However, in the apparatus of Figure 2 the filter 14a is downstream from the receiving reservoir 45 so as to filter the mixture. In such case the control valve 68 will operate responsive to the level of the liquid in the receiving reservoir 45. Thus, there is provided in the reservoir 45 an additional float 80 which controls a valve actuator or controller 76a which then controls the pneumatic pressure in the air line 78a that is connected to the valve 69 and controls the pressure on the diaphragm therein.

Howevever, the arrangement is such that as the filter 14a becomes progressively clogged the float 80 will begin to rise with the back up or rise of fluid level in the reservoir 45. The arrangement is such that increased air pressure in the line 78a causes the valve slide 70 to move and reduce the flow from the header 38 into the reservoir 45. Conversely, a lowering of the float 80 results in an increased flow through the valve 68. Of course, if the level in the reservoir 45 should drop too low, the float 66 will cause the controller 64 to close the valve 62.

It is desired that the normal operating range of the float 80 be above that level of fluid in the reservoir 45 which would cause the valve 62 to close. Thus, if the level of liquid in the reservoir 45 should drop to the minimum level of the float 80, the float 66 would still be slightly bouyed because the lowermost position of the float 80 is higher than lowermost position of the float 66, this difference being of the order of one inch.

In Figure 2 it will be noted that there is the absence of a filter upstream from the reservoirs 2,4. Accordingly, the float 74 serves as a simple level control operating the valve controller 82 to close the valve 84 when the fluid level and the reservoir 2 reach a predetermined height.

In the arrangements of Figures 1 and 2 the valve slide 70 operates on a continuously variable basis under progressive changes in air pressure from the associated valve controller 76 or 76a as the case may be. Thus, the valve orifice of the valve 68 varies progressively in size over the operating range of the level of the associated float 74 (Figure 1) or 80 (Figure 2) as the case may be. This arrangement assures smooth and consistent operation of the apparatus.

A further modified form of proportioning apparatus is shown in Figures 3 and 4wherein like reference numerals indicate like parts of the apparatus previously described with respect to Figures 1 and 2. However, in each of Figures 3 and 4the mixing header 38 is eliminated from the third or receiving reservoir 45 whereby fluid from the two conduits 34,36 is delivered directly to the portion of the reservoir 45 that contains the float valves 66, 80.

Furthermore, the slide valve 68 of Figures 1 and 2 is also eliminated from the apparatus of Figures 3 and 4.

It is desired to maintain a carbon-dioxide atmosphere above the level of the liquid in the reservoir 45.

For this purpose a float 80 controls an actuator 76a that provides an operative connection 78a with an intake valve 90 for controlling a supply c: carbondioxide to the interior of the reservoir 45.

In the apparatus of Figures 3 and 4 the manner of controlling the operation of the valve 52 differs from that shown in Figures 1 and 2. In Figures 3 and 4 there is a pair of fluid level sensors or probes 92a, 92b for detecting an upper and lower fluid level within the reservoir 45. The probes 92a, 92b provide an operative connection through leads 92 to a valve controller 94 which operates to open and close the valve 52. When the liquid level in the reservoir 45 reaches an upper limit and is detected by the probe 92b, the valve actuator 94 operates to close the valve 52 thereby causing a pressure build up in the reservoir 45, raising such pressure above that in the reservoirs 2 and 4.Consequently, the flow of fluids through the conduits 34, 36 becmome inhibited or shut offto restrict further accumulation of fluid in the reservoir 45. On the other hand, should the fluid level in the reservoir 45 drop below the probe 92a the valve actuator 94 will serve to open the valve 52, thereby equalizing the pressures within the three reservoirs 45, 2, 4, and permitting resumption of fluid flow.

In another aspect of the apparatus of Figures 3 and 4 an arrangement is provided for opening and closing the conduits 34, 36 responsive to the level of fluid within the storage tank 60. For this purpose a fluid powered cylinder 91 is provided on top of the reservoir 45 and comprises a piston-operated rod 95 the lower end of which has a cross rod 96. Each of these cross rods carries a closure member 93 for closing off the lower ends of the respective conduits 34,36.

Fluid power to the cylinder 91 is supplied through a valve 67 under control of a valve actuator 65 which, in turn, is controlled by an actuator 63. The actuator 63 is, in turn, responsive to the level of the float 61 within the storage tank 60. Accordingly, when the level within the storage tank 60 reaches a predetermined maximum, the valve 67 is opened to elevate the rod 95 and cause the members 93 to close off the lower ends of the conduit 34,36. When the float 61 drops, the valve 67 becomes opened, releasing the pressure within the cylinder 91 and allowing the rod 95 to drop downwardly, opening the lower ends of the conduits 34,36.

In the arrangement of Figure 3 there is thus provided an arrangement for automatically controlling fluid flow notwithstanding that the filter 1 4a may become progressively clogged and restrict the fluid flowtherethrough. Here, a rise in fluid level in the reservoir 45 operates the float 66 and valve 64 so as to open the valve 62, thus removing in effect, any obstruction between the filter 14a and the pump 56.

As the filter 14a further clogs and the fluid level in the reservoir 45 rises, the probe 92b operates to close the valve 94 and 52 as described above, so as to shut down the proportioner.

In Figure 4 the filter 14 is upstream from the supply reservoir 2 and a somewhat different arrangement is provided for controlling the discharge from the pump 56 to the storage tank 60. Thus, in Figure 4 a float 99 in the reservoir 2 operates actuator 100 which, in turn, controls the operation of the valve 62 independently of any control by the actuator 64.

Consequently, should the reservoir 2 become "starved" by reason of clogging of the filter 14, the lowered level of the float 99 will result in the valve 62 being closed even though the float 66 may be above that level which is necessary to cause valve 62 to close. In this way, the fluid is not exhausted from the mix reservoir 45, and cavitation in, and possible damage to, the pump 56 is avoided.

Claims (10)

1. Afluid proportioning apparatus for continuously proportioning diverse fluids, comprising a first reservoir for a first fluid, a second reservoir for a second fluid, a third reservoir below said first and second reservoirs, a conduit from each reservoir for conveying fluid by gravity flow from each of said first and second reservoirs to the third reservoir, means for maintaining equal pressures in all three reservoirs, and means interposed in each conduit and having orifices of predetermined sizes and operable in response to said equal pressures for supplying said first and second fluids in predetermined proportions to said third reservoir.

2. Afluid proportioning apparatus according to claim 1, in which said means for maintaining equal pressures includes a conduit connecting said first and second reservoirs above the liquid levels therein.

3. Afluid proportioning apparatus according to claims 1 or 2, in which said means for maintaining equal pressures comprises a conduit providing communication above the liquid levels in said second and third reservoirs, and a valve in said last-mentioned conduit and operable to close said communication and thereby allow the pressure in said third reservoir to increase relative to the pressure in said first and second reservoirs.

4. Afluid proportioning apparatus according to claim 3, including means responsive to upper and lower fluid levels in said third reservoir for actuating said valve to close the valve when the fluid level reaches the upper level and to open the valve when the fluid level reaches the lower level.

5. Afluid proportioning apparatus according to any one of claims 1 - 3, in which said third reservoir includes a mixing header and a receiving reservoir, the fluid-conveyor conduits extend from the first and second reservoirs to said mixing header, and a control valve is in the flow path between said mixing header and said receiving reservoir and is responsive to the level of fluid in one of said reservoirs for decreasing the flow of mixed fluid from said header to said receiving reservoir upon decrease of the fluid level in said one reservoir and for increasing the flow of mixed fluid from said header to said receiving reservoir upon increase of the fluid level in said one reservoir.

6. Afluid proportioning apparatus according to any of claims 1 - 4, including a storage tank for receiving the mixed first and second fluids, and means responsive to the fluid level in said storage tank for shutting off the flow of the mixed fluids from said conduits to said third reservoir when the fluid in the storage tank reaches predetermined upper level.

7. A fluid proportioning apparatus according to claim 6, including a filter in the flow path between said third reservoir and said storage tank, and a float controlled valve responsive to the fluid level in said third reservoir for reducing the supply of mixed fluid from said third reservoir when the liquid in said third reservoir drops below a predetermined level.

8. Afluid proportioning apparatus according to claim 6, including a filter upstream from one of said first and second reservoirs, and a float controlled valve responsive to the liquid level in said lastmentioned one reservoir for reducing the flow of mixed fluid from said third reservoir to said storage tank.

9. Afluid proportioning apparatus for con tinuously proportioning fluids, comprising a first reservoir for a first fluid, a second reservoir for a secondfluid, a third reservoir below said first and second reservoirs, a conduit from each reservoir for conveying fluid by gravity flow from each of said first and second reservoirs to the third reservoir, means for maintaining equal pressures in all three reservoirs, and orifice means for controlling flow of fluid from the two conduits in predetermined proportions to said third reservoir, flow of fluid to the third reservoir being terminated in response to unequal pressure conditions.

10. Afluid proportioning apparatus substantially as hereinbefore described with reference to the accompanying drawings.