US 3456678 A
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R. J. WRIGHT July 22, 1969 DEVICE FOR DISSOLVING SOLID MATERIAL IN A LIQUID SHUNT STREAM Filed May 2, 1967 2 SheetsSheet 1 INVENTOR. Ralph J. Wri
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DEVICE FOR DISSOLVING SOLID MATERIAL .[N A LIQUID SHUNT STREAM Filed May 2, 1967 2 Sheets-Sheet 2 l L x \(I/IZ 4M l 15 f: 29 5+ INVENTOR Ralph J. Wright BY Wm, 777%,
W fi 'w I 5% Attorneys United States Patent 3,456,678 DEVICE FOR DISSOLVING SOLID MATERIAL IN A LIQUID SHUNT STREAM Ralph J. Wright, Berkeley, Calif., assignor of twenty-four percent to Michael A. Grappo, and five percent to Elizabeth Reeb Filed May 2, 1967, Ser. No. 635,575 Int. Cl. E03c 1/046 U.S. Cl. 137268 17 Claims ABSTRACT OF THE DISCLOSURE Solid material, e.g., chlorine and/or acid-containing material, is dissolved in a shunt stream which is diverted from and returned to a main stream by flow through a container holding said material, return of concentrated solution to the inlet being prevented by providing a chamber of fresh liquid upstream from the container; the chamber communicates with the top of the container for partially diluting the resulting solution, which is flowed to a discharge chamber through an adjustable restriction and there further diluted with a slip stream of the shunt stream to prevent entry of highly concentrated solution into the main flow.
The invention relates to a device for dosing a liquid by diverting a shunt stream from a main flow, dissolving the material in the shunt stream by flow through a receptacle containing the solid material and returning the resulting solution to the main flow. The invention is particularly, although not exclusively, applicable to treating water which is flowed into swimming pools with a chlorine-containing material which is initially in solid form, such as pellets, in controlled amounts.
Such granular material is readily dissolved in water and its use obviates the need for complex equipment which dissolves chlorine gas in the water.
In prior equipment for dissolving granular material, a shunt stream is abstracted from a main stream being pumped into a pool, e.g., fresh water or water drawn from the pool through a tap situated upstream from a flow restriction, which may be simply a length of pipe giving flow resistance, flowed through a container holding the granules, and the resulting solution is returned to the main flow downstream from the restriction. In some devices, the fiow rate of the shunt stream is controlled by a valve.
However, certain problems have arisen with the simple dosing equipment in which the granular material is dissolved in a shunt stream that is flowed through a receptacle containing the material. The rate of dissolution of the granular material depends on the rate of relative movement of the water, so that positive means for causing agitation have been used. However, the material continues to dissolve, although more slowly, when flow ceases and there is no agitation, and after some time the solution within the container becomes so concentrated that it is highly corrosive. Moreover, the solution is often acidic. It is important to prevent contact of such chemically aggressive solution with any part of the main ice when under pressure. Pressures of 15-40 psi. and more are commonly produced by the circulating pump. When the circulating pump is shut down, the container contracts, forcing some of the concentrated liquid into the now stagnant liquid in the main flow channel. The return of some solution through the inlet of the dosing device causes a corrosive liquid to be present in the main flow channel, often coming into contact with the filter, heater and/ or other parts of the upstream and injuring the same. This contraction can also cause concentrated solution to be forced into the main flow channel through the outlet side of the dosing device.
(2) The granules are often small, being reduced from larger pellets by dissolution or supplied initially as a powder, and some of these are at times entrained by the effluent shunt stream and carried into the main flow channel. This causes an undesirably high concentration in the main flow channel and, at times, in the swimming pool or other utilizing facility. This causes corrosion of main flow channel and accessories, which are usually made of metal, and is obnoxious to occupants of the pool.
Also, it is useful to prevent escape of the concentrated solution from the container in the event that the container fails. These containers have on occasion failed, and the provision of a pit or the like for receiving the solution from a burst container is insufficient to prevent spreading of the corrosive solution if water under the pressure of the circulating pump is lost over an extended period.
Now according to the present invention, one or more of the foregoing drawbacks are obviated or minimized, the features for overcoming the several drawbacks being preferably combined.
According to one feature of the invention, the dosing device is provided with a surge chamber ahead of the container holding the granules, arranged to receive fresh liquid, whereby contraction of the container will displace fresh water or water which contains only a very low concentration of dissolved matter through the inlet into the main flow channel.
In a preferred construction, the shunt stream is fed into the container through a passageway having a nonreturn valve, and the container is in communication with the surge chamber, which is in flow communication with the outlet part of the container to dilute the solution'in that part, and which upon contraction of the container receives dilute solution directly from the container, which then displaces substantially pure liquid to the inlet. Advantageously, the chamber communicates with the said passageway through a small passage and is in communication with an upstream part of the passageway through a non-return valve which permits only flow from the chamher to the inlet.
Further, to further promote the presence of fresh water in the part of the chamber from which liquid passes to the inlet, the chamber can be partitioned by one or more walls having small ports.
According to another feature of the invention, which is useful even when the container has rigid walls, the entrainment of particles of the solid material in the effluent stream is avoided or minimized by providing a second surge chamber through which the effluent from the container is passed by a second passageway and into which chamber a small part of the inflowing, fresh liquid is diverted through a diverting passageway, being in a preferred embodiment admitted into the second surge chamber at high velocity so as to create turbulence. This will dilute the solution within the second chamber and afford an opportunity for any entrained solid material to be dissolved in the liquid. By thus diluting the eflluent solution, there is. moreover, less tendency for a high concentrated and injurious solution to enter the main flow channel when the pump is shut down.
In a preferred embodiment, the size of the diverted stream is adjusted in relation to the size of the stream which flows through the container by an adjustable proportioning valve.
There may optionally be provided a check valve for insuring that the dilute solution from the second chamber cannot pass through the diverting passageway to the inlet and thereby enter the main water system when the con tainer contracts.
Also according to another feature of the preferred embodiment, the solution flowing from the container into the second chamber flows through a narrow channel which prevents passage of any but the smallest solid particles. Further, the second passageway may be provided with an adjustable restriction, such as a needle valve, for controlling the rate of flow through the container and into the second chamber. This restricts further the entrainment of solid particles and, when the container has flexible walls and contracts, reduces the flow of the solution through the outlet into the main flow channel; hence most of the resurgence liquid flows out through the first-mentioned surge chamber.
There is also preferably provided check valve means in the main flow channel to prevent escape of water into the dosing device at an excessive rate in the event that the container fails.
The invention will be further described with reference to the accompanying drawings showing two preferred embodiments by way of illustration, wherein:
FIGURE 1 is a diagrammatic view of the dosing device and its relation to the main flow channel;
FIGURE 2 is an enlarged sectional view taken on the line 2-2 of FIGURE 1;
FIGURE 3 is a diagrammatic view of the closing device showing the flow paths of the liquid and solution therethrough, the structure being shown in detail in FIGURE FIGURE 4 is a sectional view taken on the line 44 of FIGURE 5;
FIGURE 5 is a sectional view through the dosing device, enlarged over FIGURE 3 to show the details of the parts; and
FIGURE 6 is a view similar to FIGURE 2 showing an alternative construction of the shunting connection,
Referring ot FIGURES 1 and 2, the main flow channel comprising pipes 10, 11, carries a liquid stream moved by a pump, not shown, and discharges the flow into a utilizing device, such as a swimming pool. The source may be fresh water or water withdrawn from such a swimming pool. A suitable flow-restrictive device, such as an orifice place, or merely a length of pipe or the heater, is interposed between the sections 10 and 11. Each, of these sections is fitted with a connection for taking off a shunt stream, as appears more particularly in FIGURE 2. Thus, the main flow pipe has a lateral opening to which is attached a nipple 12 and a bore and secured by a band 13 and screw 14. The shunt stream of liquid flows thence lby tubing 15 to a dosing device D, and the solution of the solid material in the shunt stream is returned to the pipe 11 through tubing 15a.
Referring to FIGURE 3, the dosing device includes a housing 16 having at the bottom thereof a coupling means from which such as a threaded sleeve 17 for attachment of the neck of the container 18 which contains granules 19 of the material to be dissolved. This container may be the shipping container in which the granules are supplied by the manufacturer, and the granules may be of any desired shape or size, e.g., they may have the appearance and size of rice grains, although particles of larger or small size may be used. Such a container is often made of plastic material, and in such case the container wall is not rigid but can be flexed outwardly so that the volume of the container increases when its contents are under pressure. The housing contains a first passageway including:
an inlet 20, a valve chamber 21, a narrow passage 22 leading downwardly from the valve chamber, a tube 23, and a discharge tube 24, which extends through the coupling means 17 and beyond the housing, so as to discharge liquid into the interior of the container 18 at a level well below its top. This passageway preferably has a non-return valve 25.
Details of these parts are shown in greater detail in FIGURE 5, from which it appears that the valve 25 normally rests by gravity on a stop 25a, but can be entrained by upward flow of liquid to close off the entrance to the tube 23. The tube 23 has lateral ports 26 of small size which establish communication with a fresh-liquid surge chamber 27 which is formed within the housing 16. This chamber advantageously has one or more transverse partitions 28, provided with one or more small holes 29, and dividing the chamber into upper and lower sections, the upper section being in direct communication with the port 26. Optionally, the top of the chamber 27 is in direct communication with the inlet part 20 of the first passageway through a non-return valve 30 which permits only the upward flow of liquid. The bottom of the chamber 27 is in communication with the top of the container 18 through an ample passageway 31, which also extends through the coupling means 17. It may be noted that various parts of the housing are assembled by any suitable method, usually involving press-fitting, although adhesives or other means may be employed.
The dosing device further includes a housing 32 defining the second surge chamber 33 which is in communication with the container through a second passageway including: a narrow, annular flow space 34, and axial bore 35 formed in a plug 36 which further carries an externally threaded and adjustable needle valve 37 which 00- operates with the entrance to the bore 35, and a connecting tube 38 which unites the housings 16 and 32 structurally. The annular flow space 34 is formed between a cylindrical bore in the coupling part 17 of the housing 16 and the plug 36 and is preferably so narrow that the passage therethrough of entrained solid particles is prevented. The housing 32 is provided with lower and upper closures 39 and 40, and the upper closure carries an upwardly extending fitting '41 which is shaped for the attachment of flexible tubing T and a downwardly extending discharge tube 42. This housing has an outlet tube 43 to which is connected a discharge tube 15a leading to the main flow channel section 11. The upper portions of the housings 16 and 32 are structurally united by a pin 44.
As appears in FIGURES 4 and 5, the inlet 20 is for-med of a separate tube which extends through the wall of the housing 16 and into a vertically elongated plug 45 which is contained within the housing 16. Several of the parts previously mentioned are contained within this pin g; among these are the aforesaid valve chamber 21 and a diverting passageway which communicates with the valve chamber through the bore of a tube 46 having at its outer end a fitting, similar to the fitting 41, for attaching the flexible tubing T, whereby the diverted stream from the valve chamber 33. The valve chamber further contains a valve plug 47, mounted for rotation therein, and connected by a screw 48 to the knob 49, which may have suitable graduations 50. The valve plug is retained within the plug 45 by a ring 50 secured by screws 51. The lower part of the valve plug 47 has a cylindrical wall which extends only partly about its circumference and which, in the position shown, fully obstructs communication of the valve chamber with the inlet 20. It also carries a foot 47a, which may extend over a sector slightly greater than that of the aforementioned wall, and which fully covers the upper end of the bore 22 when the plug is positioned as shown. Rotation of the knob 49 causes the plug 47 first to uncover the inlet 20 and, thereafter, to uncover the bore 22 gradually. This segmental diverting valve permits an accurate and sensitive adjustment of the ratio in which the shunt stream admitted through the inlet 20 is divided for flow into the bore 22 and the bore of the tube 46.
Optionally, a check valve 50 may be provided in the fitting 41 to permit flow only from the diverting passageway and tube 46 into the second chamber 33.
In operation, a portion of the liquid flowing through the main flow channel 10, 11 is diverted as a shunt stream through the tubing 15 to the inlet 20 and thence vents through the first passageway, via the valve chamber 21, bore 22 and tubes 23 and 24, into the interior of the container 18. A part of this liquid enters the chamber 27 through the ports 26. The solution of dissolved material fiows out from the top of the container through the second passageway which includes the annular space 34 and the tube 38, at a rate regulated by the needle valve 37. This effluent solution is diluted by fresh liquid admitted from the chamber 27 through the passageway 31. Upon entering the second chamber 33, this solution is further diluted by fresh liquid diverted from the incoming shunt stream by the valve within the chamber 21 to the tube T. Thereby the concentration of the dissolved material in the liquid within the chamber 33 is low enough to insure complete solution of any fine particles carried out of the container with the eflluent stream; this dissolution is further aided by turbulence within the chamber 33 caused by the downward impingement of the fresh liquid from the tube 42. The size of the diverted stream admitted by the tubing T can be adjusted by positioning the valve 47 by means of a knob 49. It may be noted that it is possible to uncover the bore of the inlet 20 before uncovering the bore 22, whereby all of the shunt stream is diverted through the tube T; this may be desirable just prior to shut-down of the system, so that only fresh liquid or liquid which contains the dissolved material in a highly diluted state flows through the tubing 15a into the main flow channel 11.
In the above operation, the pressure within the container 18 will be above atmospheric, due to communication with the circulating pump for the tubing 15. This causes a small dilation of the container 18 when it is made of plastic or other thin, non-rigid material. When the pump is stopped, the pressure is reduced and the container 18 contracts. Thereupon, liquid from the chamber 27 flows back into the inlet 20 and tubing 15, in part through the port 26 and in part through the non-return valve 30. It may be noted that the non-return valve 30 provides a return path offering a. smaller flow resistance than the port 26; also, it provides a return channel which is always available regardless of the position of the valve plug 27. This small amount of liquid which flows upwardly out of the chamber 27 displaces liquid in a tubing '15 which thereupon flows downstream from the main channel through the flow restriction and into the channel 11. Contraction of the container 18 also causes some liquid to be displaced through the outlet 43 and tubing a. It is desirable that the latter flow be made small, and this is achieved in part by the flow resistance presented by the narrow annular flow space 34 and the needle valve 37. However, some flow of liquid in the outlet direction will unavoidably occur and this will consist largely of highly diluted solution. Moreover, if the valve plug 47 is positioned to uncover the inlet While still covering the bore 22, fresh water can be circulated through the tubing T into the chamber 33 without corresponding flow of solution into the latter chamber from the container 18. When the pump is thereafter shut off, only fresh water will enter the main flow channel.
The check valve 50, when provided, prevents the somewhat corrosive solution from the second chamber from flowing through the tubing T and thence into the main fiow system.
Referring to FIGURE 6, there is shown an alternative construction of the tap connecting the tubing 15 to the pipe 10. In this modified form, the nipple 120 contains a valve chamber containing a valve member 51 which normally rests on a bar, and permits water to flow upwards into the tubing 15 at a low rate. A ball valve can be used for the valve 51. When, however, the container 18 fails, the water initially flows so rapidly that it carries the valve 50 upwards to close the outlet from the nipple. This shuts off further flow. A by-pass conduit 52 is provided in a T-fitting 53 having a normally closed cock valve 54, is connected about the valve 51. When the system is first placed into operation, the valve 54 is opened to equalize the pressure below and above the flow-responsive valve 51 to permit it to drop; the valve 54 is then closed.
The tap connecting the tubing 15a to the pipe 11 is similarly constructed, save that the by-pass conduit 52 and its fitting 53 and cock valve 54 can be omitted, since in this instance the valve 51 cannot block the return of liquid into the main flow pipe '11.
1. A dosing device for dissolving solid material in a shunt stream of liquid which is diverted from a main fiow and is returned to the main flow, comprising:
(a) a housing having coupling means for attaching thereto a container holding said solid material, a first passageway including an inlet for said shunt stream and an outlet extending through said coupling means for directing said shunt stream into such a container, and a storage chamber for fresh liquid in flow communication with said first passageway; and
(b) a second passageway in said housing also extending through said coupling means having an inlet for flowing a solution of said material in the shunt stream from such a container,
(c) said outlet of the first passageway and the inlet of the second passageway being situated different disiances from the.coupling means so that one extends beyond the coupling means, for the isolated flows of the shunt stream into and out of such a container.
2. A dosing device as defined in claim 1 which includes a non-return valve interconnecting said chamber and said first passageway for the direct flow of fresh liquid only from the chamber to the inlet, said first passageway having a flow restriction between the junction thereof with said non-return valve and the point of communication of the first passageway with the chamber.
3. A dosing device as defined in claim 1 wherein said housing has a third passageway extending through said coupling means and interconnecting said chamber and a point beyond said coupling means in the vicinity of the inlet to the second passageway for the supply of fresh liquid into such a container near the point of efllux therefrom of said solution.
4. In combination with the dosing device as defined in claim 3, a non-return valve in said first passageway for the flow of said shunt stream only into the container, whereby return fiow of liquid from such a container to the inlet of the first passageway is via said chamber.
5. A dosing device as defined in claim 1 wherein said chamber includes a partition wall subdividing the chamber into sections and having a passageway extending over only a small fraction of the wall area, one of said sections being in direct communication with said first passageway and the other section being in direct communication with said third passageway.
6. A dosing device as defined in claim 1 wherein said second passageway has an adjustable flow restriction.
7. In combination with the dosing device defined in claim 1, means defining a second chamber, said second passageway leading into said second chamber, and a diverting passageway interconnecting the first passageway to the second chamber for introducing fresh liquid from the first passageway into the second chamber, said second chamber having an outlet for the discharge of diluted solution therefrom.
8. A dosing device as defined in claim 7 wherein said housing includes adjustable means for varying the ratio of liquid flow from the inlet of the first passageway to the outlet thereof to the liquid flow through the diverting passageway.
9. In combination with the dosing device as defined in claim 7, a non-return valve in said diverting passageway connected to permit flow of liquid only into the second chamber.
10. A dosing device as defined in claim 1 which is connected to said main flow channel by:
(a) a fitting connected to said main flow channel providing a passageway, and conduit means connecting said passageway to the said first passageway,
(b) said passageway including a flow-responsive valve for closing the passageway when the flow of liquid out of said main flow channel rises to a high rate but permits flow of liquid at a low rate.
11. A dosing device as defined in claim 10 which includes a by-pass conduit connected about said flow-responsive valve, and a shut-off valve in said by-pass conduit.
12. A dosing device as defined in claim 10 wherein the outlet of said dosing device is connected to said main flow channel by a fitting connected to a downstream portion of the flow channel providing a passageway, conduit means connecting said passageway to the dosing device for the return of the dosed shunt stream, and a non-return valve in said fitting for preventing flow of liquid from the main channel through said passageway.
13. A dosing device for lissolving solid material in a shunt stream of liquid which is diverted from a main flow and is returned to the main flow, comprising:
(a) a housing having coupling means for attaching thereto a container holding said solid material, a first passageway including an inlet for said shunt stream and an outlet extending through said coupling means for directing said shunt stream into such a container, a diverting passageway, and adjustable valve means in said first passageway for diverting a variable fraction of said shunt stream from said first passageway into the diverting passageway;
(b) means defining a second chamber having an outlet said diverting passageway being in communication with the second chamber for flow said fraction of the said shunt stream into the second chamber; and
(c) a second passageway also extending through said coupling means having an inlet for receiving a solution of said material from such a container in the non-diverted part of said shunt stream and discharging into said second chamber.
14. A dosing device as defined in claim 13 wherein said adjustable valve means includes: a wall structure defining valve chamber formed in said housing communicating with an upstream part and with a downstream part of said first passageway through separate openings in said wall structure, said diverting passageway also opening into said chamber, and a plug mounted for rotation within said chamber having separate walls controlling the degrees of opening of said parts of the first passageway with the chamber.
15. A dosing device as defined in claim 13 wherein said diverting passageway is in communication with said second chamber through a tube extending into the chamber.
16. A dosing device for dissolving solid material in a shunt stream liquid which is diverted from a main flow and is returned to the main flow, comprising:
(a) a housing having coupling means at the bottom for attaching a container holding said solid material, a first passageway including an inlet for said shunt stream and an outlet tube extending through said coupling and beyond the bottom of the housing for directing said stream into a lower part of such a container;
(b) a second pasageway also extending through said coupling means having an inlet situated above the outlet of the first passageway for discharging a solu tion of said material in the shunt stream form an uppe part of such container, said second passageway including a downwardly directed bore in said housing and a plug situated within said bore with radial clearance to define a narrow annular flow space.
17. The dosing device defined in claim 16 wherein said plug has, at its upper end, a discharge bore which communicates with said annular flow space through a connecting bore, and contains an adjustable needle valve cooperating with the part of the plug defining said discharge bore.
References Cited UNITED STATES PATENTS 2,711,928 6/ 1955 Randa l37268 XR 3,195,558 7/1965 Klueber et al. 137-268 3,386,808 6/1968 Handeland 137268 XR M. CARY NELSON, Primary Examiner ROBERT J. MILLER, Assistant Examiner