US3638833A

US3638833A - Means for chlorinating swimming pools

Info

Publication number: US3638833A
Application number: US9900A
Authority: US
Inventors: Robert S Lucas
Original assignee: Purex Corp Ltd
Current assignee: Hydrotech Chemical Corp
Priority date: 1970-02-09
Filing date: 1970-02-09
Publication date: 1972-02-01
Anticipated expiration: 1989-02-01
Also published as: DE2105499C3; ZA71434B; GB1332725A; DE2105499A1; DE2105499B2

Abstract

Apparatus for sanitizing swimming pools in which the sanitizing agent such as chlorine-containing powder or tablets is metered into circulating water to avoid undue concentrations of agent in water. The treated water is withdrawn to the pool and not permitted to stand in the lines between filtering cycles. separately valved inlet and outlet ports in the agent-water mixing chamber are opened or closed by independent floats which maintain a desired water level in the mixing chamber during water circulation and enables closing of the chamber outlet after gravity draining of water from the chamber.

Description

I United States Patent 1151 3,638,833 Lucas Feb. 1, 1972 [54] MEANS FOR CHLORINATING 3,171,449 3/1965 Ellms et a1. ..222/83.5 SWIMMING POOLS 2,761,562 9/1956 Moody ..23/267 E 1,216,051 21917 B l ..23 [72] Inventor: Robert S. Lucas, Harbor City, Calif. 3 094 '34 41963 32: 5 [73] Assignee: Purex Corporation, Ltd., Lakewood, Calif. 3,507,624 4/ 1970 Schneider et al. ..239/310 X [22] Filed. Primary ExaminerStanley H. Tollberg [21] Appl.No.: 9,900 Assistant Examiner-Larry Martin Attorney-White, Haefliger & Bachand [52] U.S. Cl ..222/57, 23/267 E, 210/123,

137/268, 222/67, 222/448 [57] ABSTRACT [51 lllt- Apparatus for anitizing swimming pools in [he anitiz. Fleld 0 Search 57, agent such as chlo ine.containing powder or tablets is me. 222/365, 83-5, 88; 37/268; 23/267 tered into circulating water to avoid undue concentrations of 272-8; 210/119 134; 251/9 agent in water. The treated water is withdrawn to the pool and not permitted to stand in the lines between filtering cycles. [56] References cued separately valved inlet and outlet ports in the agent-water mix- UNITED STATES PATENTS ing cha mber are opened or closed by independent floats which maintain a desired water level in the mixing chamber dunng 3,406,870 10/1968 Amesonm 222/67 X water circulation and enables closing of the chamber outlet 2,698,292 12/l954 21023 X after gravity draining ofwater from the chamber. 3,356,460 12/1967 King et al.. ..251/9 3,128,915 4/ 1964 Matter ..222/448 X 14 Claims, 6 Drawing Figlres MEANS FOR CHLORINATING SWIMMING POOLS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention has to do with swimming pool maintenance. To be healthful, swimming pools must be maintained free of bacteria which are introduced through use of the pool and by exposure of the pool to the environment. Thus, maintenance is a continuing effort. The periodic addition of sanitizing chemicals is the most popular way to maintain satisfactory bacteria levels in swimming pools. The action of the sun and other factors such as heat operate to destroy added chemicals and fresh quantities must be added. To do so the pool owner pours liquid hypochlorite solution into the pool or tosses one or more packets of powdered sanitizing agent e.g., sodium trichlorocyanurate, into the pool. In either case personal attention of the owner is required and care must be taken to get accurate dosage and to avoid harmful contact with skin or clothing of strong chemicals or even their vapors.

2. Prior Art More recently devices have been provided which automatically add sanitizing chemicals to swimming pool water. These devices are generally adapted to deliver chlorinating, brominating or other active product to the water circulation system normally associated with a swimming pool as a part of the filtering system. These filtering systems operate for a greater or lesser part of each day and accordingly, there is a rise and fall of water pressure downstream of the pump which circulates water for filtering.

In US. Pat. No. 3,406,870 to Arneson, a device is disclosed which has a common inlet and outlet to a mixing chamber for water and chlorinating or other powdered agent. Upon start up of the filter cycle circulation water enters the mixing chamber, rising up to a predetermined level which serves to meter chlorinating agent from a larger supply into the mixing chamber. Upon shutdown of the water circulation system, the highly concentrated chlorine bearing solution drains through the outlet into the circulation system where it lies until the pump is restarted, usually many hours later. The continuing presence of corrosive chemical solutions in piping is not desirable and is to be avoided, if possible.

Other workers in the art have developed automatic chlorinators which dump metered amounts of chlorine-bearing powders into a circulating stream, thus overcoming the undue solution concentration problem, if the chlorine-containing solution is not generated or retained in the mixing chamber between circulation periods. Thus far, however, circulating type automatic chlorinators have employed rocker arm valves to oppositely open and close the inlet and outlet ports. A float arm connected to the rocker arm closes the inlet when high and closes the outlet when low, all to maintain the water level in the chamber within a close range. At the desired level, both inlet and outlet are open, inflow and outflow are balanced and the water contacts a supply of controllably soluble chlorinating powder partly immersed in the water, thus to meter agent into the water. Upon shutdown of the pump, a slight drop in water in the chamber which may still leave the water in contact with the chlorinating powder, occurs and the outlet immediately closes. The water in the chamber with chlorine material dissolved therein is trapped until the next cycle whereupon it is initially discharged into the loop piping where it may be harmfully corrosive before being flushed with additional water back to the pool.

SUMMARY OF THE INVENTION It is a major objective of the invention to provide an automatic chlorinator in which the chlorine-bearing powdered material or other sanitizing chemical is dissolved in a circulating water stream and at the onset of the water circulation cycle and in which the mixed water is drained by gravity from the mixing chamber at the end of the circulation cycle substantially free of chlorine or other aggressive sanitizing chemical so that sporadic introduction of highly concentrated chemical solutions into the circulation loop piping is avoided.

The invention provides apparatus for sanitizing swimming pool water which includes a mixing chamber having an inlet port and a relatively lower outlet port all above the swimming pool to be sanitized, means periodically circulating pool water through the chamber including a pump and conduit leading to and from the pool, the circulating means introducing water from the conduit on the discharge side of the pump to the chamber through the inlet port and withdrawing water from the chamber through the outlet port to conduit on the suction side of the pump. The apparatus further includes means introducing a metered quantity of normally solid water soluble sanitizing agent in response to periodic water circulation through the chamber for mixing with water at the onset of the water circulation period.

Such means may include a supply chamber containing a supply of the sanitizing agent and having a bottom opening vertically spaced above the mixing chamber, a metering cup open to and below the mixing chamber opening, valve means movable between the openings to sequentially communicate the supply chamber with the metering cup and the metering cup with the mixing chamber to deliver metered amounts of agent from the supply to the mixing chamber, The valve means may comprise a pair of valve members vertically spaced a distance to be movable selectively into alternate blocking relation with one or the other of the bottom openings and float means in the mixing chamber connected to the valve members to raise or lower the valve members together in response to water level changes in the mixing chamber, to first charge the metering cup from the supply chamber at the onset of water circulation and to empty the metering cup into the mixing chamber following the water circulation period and after water has substantially completely drained therefrom.

Alternatively, the sanitizing agent introducing means may include a supply of the agent disposed in an elongated container which is mounted vertically on the top wall of the mixing chamber in a manner to have a lower container portion submerged in water periodically circulated through the chamber and out of contact with water when water circulation ceases and an upper container portion above the water as a continuation of the lower portion, the submerged container portion having a water passing aperture permitting dissolution and dispersal of agent from the lower container portion, the agent in the upper portion being arranged to descend by gravity to continually replace dissolved and dispersed agent in the lower portion.

Two independent valve means are provided in the chamber separately controlling water flow through the inlet and the outlet including a first float-controlled inlet valve operative to limit the level of water in the chamber during water circulation periods and a second float-controlled outlet valve operative to maintain the outlet open to permit substantially complete gravity draining of water from the chamber following termination of the water circulation period and thereafter to close the outlet valve.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be further described as to specific illustrative embodiments in connection with the attached drawings in which:

FIG. I is a vertical section view of an automatic sanitizing device according to the invention in its mode following completion of the water circulation period and draining of the device;

FIG. 2 is an enlarged view partly in elevation of the open inlet valve shown in FIG. 1;

FIG. 3 is a view like FIG. 1 and showing the automatic sanitizing device in the maximum fill condition during the water circulation period;

FIG. 4 is a view like FIG. 2 and showing enlarged the inlet valve of FIG. 3;

FIG. 5 is a view generally similar to FIG. 1 of an alternate form of the device particularly as to the powder-introductive means; and

FIG. 6 is a view in section taken along line 6-6 in FIG. and enlarged, of the outlet valve and associated float control.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to the attached drawings and particularly FIGS. 1-4, there is shown an automatic pool water sanitizing device D connected across water recirculation system pump P which comprises conduit 1 leading from the pool to the pump and conduit 2 which returns the water to the pool. Device D is connected to the recirculation system conduit 1 and 2 by tubing 3 connected into conduit 2 on the discharge or pressure side of pump P and tubing 4 connected into conduit 1 on the intake or suction side of the pump. Device D is thus connected in a side stream having countercurrent flow to the main recirculation stream in conduit 1 and 2.

The device D comprises a housing 5 having a lower portion 6 defining a mixing chamber 7 and an upper portion 8 housing sanitizing agent introducing means 9 to be later described. Lower housing portion 6 includes vertical sidewall 10 and horizontal bottom wall 11. A water inlet 12 is provided through sidewall 10 and a water outlet 13 is provided adjacent bottom wall 11. An overflow drain port 14 is provided above the normal water level 15 (FIG. 3). Fitting 16 comprising threaded annular stem 17 which connects to tubing 18 is fixed in the overflow drain port 14 by means of hexagonal nut 19 in the chamber 7 and wingnut 20 outside the chamber. Tubing 18 is secured to stem 16 with ribbed collar 21 threaded onto the stem.

The water inlet port 12 is provided with a fitting 22 comprising a threaded annular stem 23 having a nozzle 24 formed in tegrally therewith to project into chamber 7 when the stem is secured in the inlet port by wingnut 25 outside the wall 10 and U-bracket 26 inside the wall. As with the drain port fitting 16 the inlet port 22 has an internally threaded collar 27 which secures tubing 3 to the stem 23 whereby conduit 2 is communicated with chamber 7 through inlet port 12. U-bracket 26 comprises a base 28 mounted flat against the wall 10 within the chamber 7 and a pair of parallel ears 29 normal to the base. A shaft 30 extends between the ears 29 slightly below and beyond nozzle 24 and parallel to the base 28. A rocker arm 31 is mounted on the shaft 30 to pivot therearound. The arm 31 has a valve surface 32 in the form of resilient e.g., rubber disc 33 inset in the arm opposite nozzle 24 to engage the nozzle when the arm is rotated clockwise around the shaft 30. A compression spring 34 is provided between strap 35 and arm 31 behind disc 33 to urge the arm clockwise against the pressure of water entering the chamber through inlet nozzle 24. Rocker arm 31 movement is controlled by float 36 carried on rigid angle support 37 connected to the rocker arm at 38. Float 36 is of buoyant material to be lifted upwardly by water in the chamber 7 (see FIG. 3) thereby to cause rocker arm 31 to rotate clockwise toward the nozzle 24 ultimately to close off the nozzle when the water level is above that desired i.e., above the line 15 level. Accordingly, it will be seen that opening and closing of inlet port 12 is responsive to the water level in chamber 7.

The outlet port 13 comprises beveled opening 39 in the rib 40 extending from the middle point in chamber 7 to sidewall 10. Passage 41 formed in rib 40 leads from outlet port opening 39 to sidewall opening 42 and secured there by nut 44 provides connection with tubing 4 communicating with suction conduit 1 and fastened to threaded stem 45 of the fitting with not 46 and collar 47.

A second float 48 separate from and independently operative from the float 36 is provided in the chamber comprising buoyant material 49 and rigid cap 50. Vertical guides 51 positioned circumferentially about float 48 limit float movement to vertical travel. A resilient annular plug valve 52 suitably tapered endwise for smooth insertion into outlet port opening 39 is carried by the float 48 to be above and vertically aligned with the outlet port opening to enter and close the same when the float is in its downwardmost position. Rod 53 carrying valve body 54 at its upper extent extends through cap and buoyant material 49 to provide a projection 55 at its lower extent onto which the annular plug valve 52 is secured. The bouyancy of the float 48 is such that when the chamber 7 is water filled the plug valve 52 is lifted off the outlet port 13 to permit continuous water passage from the chamber (see FIG. 3). After cessation of a water circulation period the float 48 remains spaced above outlet port 13 as the water drains from chamber 7 until the substantially complete draining of water permits lowering of the plug valve into the opening 39 of the outlet port 13. It will be noted that no substantial amount of water is trapped within the chamber 7 and that which remains is well out of contact with the sanitizing agent, as will now be described.

With further reference to FIGS. 1 and 3 the valve system depicted may be used with a sanitizing agent introducing means 9 comprising a supply chamber 56 containing a supply of the sanitizing agent 57 e.g., normally solid, water-soluble chlorine containing chemical powder such as sodium or potassium dichloroisocyanurate, obtained from inverted container 58. Container 58 is a replaceable unit adapted for use with the presently disclosed chlorinators by threaded insertion of container neck 59 into receptacle 60 formed in generally conical cap 61. The container top may comprise a severable membrane 62 e.g., of thin plastic which is cut circularly by knife 63 mounted on support 64 within the receptacle 60 e.g., about 300 as the container neck 59 is screwed into the receptacle. The membrane 62 then depends into the supply chamber 56. Complete separation of the membrane 62 is not advisable since plugging of agent flow from the chamber may result.

The supply chamber 56 comprises a generally cylindrical upper wall 65 and a conical lower wall 66 terminating in a bottom opening 67 vertically spaced above the mixing chamber 7. An annular resilient sealing ring 68 is fitted in the bottom opening 67. Agent delivered from container 58 is stored in supply chamber 56 for passage through the opening 67.

Generally conical metering cup 69 is provided open to and below the supply chamber 56 with its bottom opening 70 having annular sealing ring 71 fitted therein, vertically below the supply chamber bottom opening 67 and above the mixing chamber 7. The volume of metering cup 69 is variable by vertical adjustment of the cup relative to the supply chamber lower wall 66. Adjustment may be made by loosening wingnuts 72 on bolts 73 projecting radially from the metering cup 69 through opposed vertical adjustment slots 74 in upper portion 8 of the housing 5 raising or lowering the cup and retightening the nuts. The metering cup 69 is mounted to slide vertically in annular channel 75 defined by circular projection 76 extending downwardly from the cap 61 and the exterior of upper wall 65 of the supply chamber 56 which is fitted onto smaller diameter circular projection 77 also extending downward from the cap.

Annular seals

78 and 79 are provided on the exteriors of the supply chamber 56 and metering cup 69 respectively to seal the supply chamber 56 contents from water vapor in mixing chamber 7.

When the metering cup 69 has been adjusted to the desired volume and the supply chamber 56 is filled with powdered sanitizing agent, vertical movement of valve body 54 will sequentially communicate the supply chamber 56 with metering cup 69 and then metering cup 69 with mixing chamber 7 by movement of valve member surfaces 80 and 81 through the planes of

bottom openings

67 and 70 respectively. Thus, as seen in FIG. 1, draining of water from mixing chamber 7 causes float 48 to settle to the bottom of the chamber. This causes valve body 54 carried by rod 53 on the float 48 to be lowered. The valve body 54 is sized to seal the bottom opening 67 in supply chamber 56 but it is provided at its uppermost end with valving surface 80 which passes through the plane of the chamber opening 67 to permit powdered material 57 to flow into metering cup 69 in measured amount determined by the adjusted volume of the cup.

In FIG. 3, the water is at the operating maximum level and the float 48 in the raised position. This causes valve body 54 to move upwardly until bottom opening 70 in metering cup 69 is cleared by valving surface 81 of the valve bodyenabling powdered material 57 previously charged to the metering cup to fall into the water at 82 circulating through the mixing chamber 7. This metered deposit of sanitizing agent occurs at the onset of water circulation by the pump P and not at its termination, so that the agent is thoroughly diluted and well delivered to the pool when the circulating system is shut down, hours later. Of course, on again shutting off pump P, the metering process is repeated and a fresh charge of sanitizing agent is admitted into the pool water on recommencement of the circulation cycle.

In FIG. 5 where like numerals indicate like parts in the preceding Figures, an alternate arrangement for sanitizing agent introduction is depicted including an elongated cylindrical container 83 having a screwcap 84 in which a supply of the agent 57 in tabletted form is disposed. The container 83 is mounted vertically in the housing cap 611 on housing 5 defining the mixing chamber 7 to have its lower portion 85 submerged in the water 83 circulating through the mixing chamber by virtue of the action of the pump P and the inlet and

outlet port valves

12 and 13 which operate as hereinbefore set forth. The container upper portion 86 extends above the water 82 as a continuation of the lower portion 85. Waterpassing apertures 87 are provided in container lower portion 85 to permit dissolution and dispersal of agent 57 disposed below the waterline 15. The smooth interior wall 88 of the container 83 permits continual replacement of agent 57 dissolved from the lower container portion 85 by gravity descent. The solubility of the tabletted agent is controlled to provide disintegration of the tablets over time and thus, to provide a metered agent introduction into the water 82.

The upper portion 86 of the container is externally threaded at 89 to facilitate vertical adjustment of the container lower portion 85 with respect to the mixing chamber water level to allow more or less incursion of water into the container lower portion, thus to limit or increase dissolution of agent and its dispersal into the pool by pump P through filter F.

The outlet port 13 best shown in FIG. 6 includes a boss 90 having a peripheral groove 91 and a central passage 92 communicating with passage 41 in rib 40 leading to the suction conduit 1. Boss 90 is provided with a beveled opening 391 into which resilient valve 521 tapped into rod 531 with screw 93 fits to close the opening 391 and the outlet port 13. Rod S31 is supported by cage structure 94 anchored to boss 90 by inwardly projecting rib 95 in groove 91. Cage structure 94 has a top opening 96 through which rod 531 projects. Float 481 comprises buoyant body 491 centrally mounted on rod 531 with rod head 97.

It will be apparent that the elevational difference between inlet port 12 and outlet port 13 ensures no water contact with agent when the pump P is shut down unlike those systems where differences in water level between the on and off conditions are minimal.

Iclaim:

1. Apparatus for sanitizing swimming pool water which includes a mixing chamber having an inlet port and a relatively lower outlet port all above the swimming pool to be sanitized, means periodically circulating pool water through the chamber including a pump and conduit leading to and from the pool, said means circulating water from conduit on the discharge side of the pump to the chamber through said inlet port through said chamber and through the outlet port to conduit on the suction side of the pump, means introducing a metered quantity of normally solid, water-soluble sanitizing agent into said chamber in response to periodic water circulation through the chamber for mixing with water at the onset of the water circulation period to dissolve said agent in water circulating through said chamber, two independent valve means in the chamber separately controlling waterflow through the inlet and outlet ports including a first float-controlled inlet valve operative to limit the level of water in the chamber during water circulation periods and a second float-controlled outlet valve operative to maintain the outlet open to permit substantially complete gravity draining of water from the chamber following termination of the water circulation period and thereafter to close the outlet valve.

2. Apparatus according to claim 1 in which said agent-introducing means includes a supply chamber containing a supply of the agent and having a bottom opening vertically spaced above the mixing chamber, a metering cup open to and below the supply chamber opening and having a bottom opening vertically below the supply chamber opening, valve means movable between said openings to sequentially communicate the supply chamber with the metering cup and the metering cup with the mixing chamber to deliver metered amounts of agent from the supply to the mixing chamber, said valve means comprising a pair of valve members vertically spaced a distance to be movable into alternate blocking relation with one or the other of said bottom openings, and float means in said mixing chamber connected to said valve members to raise or lower said valve member together in response to water level changes in said mixing chamber to first change the metering cup from the supply chamber at the onset of the water circulation period and to empty the metering cup into the mixing chamber following the water circulation period and after water has substantially completely drained therefrom.

3. Apparatus according to claim 2 including also a resilient annular seal in each of said bottom openings and in which said valve means includes a cylindrical valve body having oppositely tapered upper and lower ends defining said valve members, said body having a diameter to slidably engage said seals.

4. Apparatus according to claim 3 in which said float means is also operatively connected to said outlet valve.

5. Apparatus according to claim 4 including also an agent supply container and means carried on said supply chamber mounting said container to empty into said supply chamber, said mounting means including an upwardly opening receptacle on top of said chamber adapted to receive the neck of an inverted supply container.

6. Apparatus according to claim 5 in which said agent supply container has a top comprising a severable membrane and including also cutting means carried in the receptacle opposite said top to sever the membrane upon rotation of the container neck within the receptacle.

7. Apparatus according to claim 1 in which said agent-introducing means includes a supply of the agent disposed in an elongated container, said container being mounted vertically on the top wall of said chamber in a manner to have a lower container portion submerged in water periodically circulated through the chamber and out of contact with water when water circulation ceases and an upper container portion above the water as a continuation of the lower portion, said submerged container portion having a water-passing aperture permitting dissolution and dispersal of agent from said lower container portion, the agent in said upper portion being arranged to descend by gravity to continually replace dissolved and dispersed agent in the the lower portion.

8. Apparatus according to claim 7 in which said container extends through the chamber top wall and including also cooperating means on said container and wall securing said container to said wall in vertically adjustable relation.

9, Apparatus according to claim 8 in which said container has a vertically extended externally threaded portion to be thread adjustable relative to said chamber top wall.

10. In combination a swimming pool, a water recirculation system for the swimming pool including a pump, a filter and conduit forming a recirculation loop between the pool, the pump and the filter; and flow connected across said pump: apparatus for sanitizing the swimming pool water which includes a mixing chamber having an inlet port and a relatively lower outlet port all above said swimming pool, means periodically operating the pump to circulate pool water through the mixing chamber including tubing flow connecting the chamber inlet port with the discharge side of the pump to the chamber through said inlet port and tubing flow connecting the chamber outlet port to the suction side of the pump, a sanitizing agent supply above water in the mixing chamber and means controllably introducing said agent into water then circulating through the mixing chamber in response to periodic rise and fall of water in the chamber at the beginning and end of periodic pump circulation of the water to add sufficient agent to sanitize the pool between periodic pump circulations, and two independent valve means in the chamber separately controlling waterflow through the inlet and outlet ports including a first float-controlled inlet valve operative to limit the water level in the mixing chamber during water circulation through the chamber and a second float-controlled outlet valve operative to maintain the outlet open to permit complete gravity draining of water from the chamber prior to closing the outlet upon cessation of water pumping.

11. Apparatus for sanitizing swimming pool water which inciudes a mixing chamber having an inlet port and a relatively lower outlet port all above the swimming pool to be sanitized, means periodically circulating pool water through the chamber including a pump and conduit leading to and from the pool, said circulating means introducing water from the conduit on the discharge side of the pump to the chamber through said inlet port and withdrawing water from the chamber through the outlet port to conduit on the suction side of the pump, means introducing a metered quantity of normally solid water-soluble sanitizing agent into said Chamber in response to periodic water circulation through the chamber for mixing with circulating water at the onset of the water circulation period, valve means in the chamber separately controlling waterflow through the inlet and the outlet, said valve means including a float-controlled outlet valve operative to maintain the outlet open to permit substantially complete gravity draining of water from the chamber following termination of the water circulation period.

12. Apparatus for periodically sanitizing circulating swimming pool water including a mixing chamber adapted to contain a continuously circulating body of pool water at relatively higher levels during circulation periods and relatively lower levels between such periods, a sanitizing agent supply to the chamber and means supporting the sanitizing agent at a level within the chamber to be at least partly immersed in said pool water body during said water circulation periods and not so immersed between such periods.

13. Apparatus according to claim 12 in which said chamber is provided with an inlet port and an outlet port and including also valve means controlling waterflow through said ports to define said water levels.

14. Apparatus according to claim 13 in which said outlet valve is float controlled to permit substantially complete gravity draining of water from the chamber.

UNITED STATES PATENT OFFICE CERTIFICATE OF COEC'HQN Patent No. 3,638,833 Dated February 1, 1972 lnventor(s) Robert S. Lucas It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3, line 36; the inlet port 22 has an internally threaded collar 27 which" should read the inlet port fitting 22 has an internally threaded collar 27 which Column 7, line 15; closing the outlet upon cessation of water pumping." should read closing the outlet valve upon cessation of water pumping.-

Signed and sealed this 20th day of June 1972.

(SEAL) Attest:

EDWARD M.FLETCHER, JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents ORM PO-105O (10-69) USCOMM-DC 5O376-P69 U.S. GOVERNMENT PRINTING OFFICE I969 0-366-334

Claims

9. Apparatus according to claim 8 in which said container has a vertically extended externally threaded portion to be thread adjustable relative to said chamber top wall.

11. Apparatus for sanitizing swimming pool water which includes a mixing chamber having an inlet port and a relatively lower outlet port all above the swimming pool to be sanitized, means periodically circulating pool water through the chamber including a pump and conduit leading to and from the pool, said circulating means introducing water from the conduit on the discharge side of the pump to the chamber through said inlet port and withdrawing water from the chamber through the outlet port to conduit on the suction side of the pump, means introducing a metered quantity of normally solid water-soluble sanitizing agent into said chamber in response to periodic water circulation through the chamber for mixing with circulating water at the onset of tHe water circulation period, valve means in the chamber separately controlling waterflow through the inlet and the outlet, said valve means including a float-controlled outlet valve operative to maintain the outlet open to permit substantially complete gravity draining of water from the chamber following termination of the water circulation period.