US 3788340 A
A cooling tower water control system operated by means of a ring float, a ring magnet fastened thereto, four magnetic reed switches enclosed by four individual tubes mounted in a parallel direction inside an enclosing tube, said ring magnet sliding freely along and around the enclosing tube in a vertical direction. The system is enclosed in a cylindrical case, closed at the top by a removable cap supporting electrical wires therethrough and having an orifice on the side wall and close to the bottom allowing sump water to enter and leave freely. The necessary support for mounting the system to the water sump is attached to the outer surface of the cylindrical case. Interlocking relays, A.C. valves, pumps, hydraulic valves, switches, solenoid valves, drivers and neon indicators are also basic parts of the control system.
Claims available in
Description (OCR text may contain errors)
United States Patent [191 OLeary et al.
[ Jan. 29, 1974 1 COOLING TOWER WATER CONTROL SYSTEM  Inventors: Richard P. OLeary, 15 Mariam Dr.,
Bellvale, NY. 10912; Charles F. Kapr, 212 Woodland Rd., New Milford, NJ. 07646  Filed: June 28, 1971  Appl. No.: 157,220
 US. Cl 137/93, l37/10l.25, 200/84 C, 335/206  Int. Cl G05d 11/08, HOlh 36/02  Field of Search. 200/84 C, 61.2; 335/205, 206; 137/93,101.25,101.27, 412, 416
Primary Examiner-Martin P. Schwadron Assistant Examiner-Richard Gerard Attorney, Agent, or Firm-Constantine A. Michalos  ABSTRACT A cooling tower water control system operated by means of a ring float, a ring magnet fastened thereto, four magnetic reed switches enclosed by four individual tubes mounted in a parallel direction inside an enclosing tube, said ring magnet sliding freely along and around the enclosing tube in a vertical direction. The system is enclosed in a cylindrical case, closed at the top by a removable cap supporting electrical wires therethrough and having an orifice on the side wall and close to the bottom allowing sump water to enter and leave freely. The necessary support for mounting the system to the water sump is attached to the outer surface of the cylindrical case. Interlocking relays, A.C. valves, pumps, hydraulic valves, switches, solenoid valves, drivers and neon indicators are also basic parts of the control system.
The invention automatically and accurately controls the water level in the sump and the concentration of treating chemicals added thereto through a three-phase operation cycle. Said cycle comprises evaporation of a predetermined amount of water through the cooling action of the tower, flushing or blow-down of another predetermined amount of water along with used treatment chemicals, and replenishing of the sump water and treating chemicals to their initial level and concentrations respectively.
10 Claims, 4 Drawing Figures PATENTEDJAN 29 m4 3, 7 8 8 340 sum 10F 3 FIG Tr-r'r-rw-n UVVENTORS RICHARD P O'LEARY CHARLES E KAPR ATTORNEY PATENTEDJAH 29 m4 SHEET 3 OF 3 Eu mw T mm WWW t ML. mw W mm I wfim E t ..||F vm mm mm Nw mm I 3 INVENTORS RICHARD R OLEARY CHARLES F KAPR ATTORNEY COOLING TOWER WATER CONTROL SYSTEM BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to water control systems and more particularly to control systems used in Water cooling towers. It also relates to systems controlling the concentration of naturally occurring salts in the water of cooling towers as well as the concentration of treating chemical added thereto for the purpose of preventing scale formation, corrosion of equipment, development of algae and/or fungi, etc.
2. Description of Prior Art In usual meter/counter water control systems where two are all three of the operational phases overlap in time, there will be a relatively large wastage of water and treating chemicals. Another problem which could not be solved by previous systems, even those employing a distinct three-phase operation cycle, is the great range within which the concentrations of salts and treating chemicals vary during the various phases of operation due to the relative insensitivity of those systems to small changes of the water level and said concentrations thereof The device described in the present invention solves these problems in a very satisfactory fashion by providing for a three-phase operational cycle, having three non-overlapping distinct phases, viz., evaporation of a predetermined amount of water, blow-down of another predetermined amount of water along with the used treating chemicals contained therein, and make-up of the water and treating chemicals to their initial level and concentrations respectively, occurring successively but separately thereby resulting in substantial savings of fresh water and treating chemicals.
Furthermore, by using magnetic reed switches the present invention is highly sensitive to small changes of the water level in the sump, thereby controlling the level with great accuracy, and accordingly keeping the concentration of treating chemicals within a preset, narrow range automatically and continuously. Due to the use of magnetic reed switches and high sensitivity, the present invention may be used with water sumps varying greatly in shape and volume since the relative position of said switches can be very easily adjusted at even very small distances from each other by sliding the housing tubes so as to activate or deactivate the valves of the system after very small changes of the water level.
Finally, the present invention, being simple in design and relatively small in size, can be inexpensively constructed, can be mounted at any point close to the water level inside or outside the sump, and requires very little maintenance and power for the operation thereof.
SUMMARY OF THE INVENTION The purpose of the present invention is to control the level of the water and the concentration of treating chemicals added thereto in a water cooling tower automatically and continuously. The invention operates by means of four magnetic reed switches, a ring float and ring magnet sliding freely in a vertical direction along and around said switches. Vertical travel of the float and magnet attached thereto, caused by changes of the water level in the sump thereof, activates the magnetic reed switches which in turn operates relays, valves, and pumps, thereby effecting the operation cycle. Said cycle comprises three distinct phases, viz., evaporation of a predetermined amount of water through the operation of the cooling tower, flushing or blow-down of another predetermined amount of water along with used treating chemicals contained therein, and replenishing or make-up of the sump water and treating chemicals to their original level and concentrations respectively. The blow-down phase serves the specific purpose of periodically unloading the sump water of naturally occurring salts and consumed treatment chemicals, thereby keeping their concentrations always below the saturation level and avoiding the formation of scale.
It is another object of the invention to save in the consumption of fresh water and treating chemicals by keeping the three phases of the operation thereof distinct and separate, thus allowing no fresh water or treating chemicals to enter the sump before the blowdown phase is over.
A further object of the invention is to provide means for the automatic addition of a predetermined amount of treating chemicals to the ssump water during the make-up phase and keeping the concentrations of said chemicals constant within a very narrow range throughout the operation cycle.
These and other objects and advantages of themesent invention will be apparent from the following description, the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing the arrangement of the device described in the present invention in relationship to the cooling tower and the water sump;
FIG. 2 shows a side view of the main control unit;
FIG. 3 shows a top view of the main control unit; and,
FIG. 4 shows a schematic diagram of the auxiliary control unit containing the electrical circuits and the hydraulic system.
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the Figures of the drawings which illustrate a preferred embodiment of the invention, FIG. 1 shows the main control unit 10, fastened on the wall of the water sump 12 of cooling tower 14 so that the water level 16 varies within the range of the magnetic reed switches housed in unit 10 during a full operational cycle of the invention. Also shown in FIG. 1 is sealed conduit 18 housing the electrical wiring to the magnetic reed switches, blow-down solenoid valve 20 leading from the water sump to the drain through the condenser return line 22, make-up solenoid valve 24 and fresh water line 26, feed pump 28, dispersion pan 30, and treating chemical feed pump 32.
FIG. 2 shows the four magnetic reed switches, viz., the high water level make-up switch 34, the blow-down switch 36, the normal low water level switch 38 and the alarm low water level switch 40. In addition, four plastic tubes 42, 44, 46 and 48 are provided to house said switches, and a ring float 50 made of foam plastic and a ring magnet 52 fastened thereto. The switch tubes are housed in a plastic tube 54 which is fastened to the bottom plate 56 of the outer plastic cylindrical housing 58. Housing 58 is enclosed at the top by a tightly fitting, re-
movable plastic cap 60 bearing a watertight conduit fitting 62 for supporting the switches wiring 64.
The inner plastic tube 54 is arranged and held in a coaxial position with the housing cylinder 58 by means of a plastic ring 66 fastened to the inner tube 54 and closed at the top by a tightly fitting rubber stopper 68. Said stopper 68 bears four holes through which the plastic tubes 42, 44, 46 and 48 housing the magnetic switches are inserted and tightly held in place. By sliding the housing tubes 42, 44, 46 and 48 up and down in a vertical direction the levels of the magnetic switches 34, 36, 38, and 40 can be individually adjusted with high precision and accordingly the various water levels at which said swtiches are activated can be preset as desired. An orifice 70 on the wall housing case 58 and close to the bottom thereof allows the sump water the enter or leave the device and cause the upeard or downward movement of float 50 and magnet 52 accordingly. The device is fastened on the inside wall of the water sump by means of a plastic mounting bracket 72 bearing mounting holes 74, and plastic spacers 76 fastened thereto.
A detailed description of the complete cycle of operation of the present invention follows by means of reference to the drawings. After evaporation of a predetermined amount of water through the action of the cooling tower 14 in what is generally referred to hereinafter as the evaporation phase, the initial water level 78 drops to 80 thus causing the float 50 and magnet 52 attached thereto to travel downward and close switch 36 which actuates the blow-down relay 82 and blow-down solenoid valve and causes make-up interlocking relays 84 to hold out the make-up relays 86 and make-up solenoid valve 24, thereby allowing a predetermined amount of sump water to be discharged to the sewer. The action described heretofore constitutes the second or blow-down phase of the operational cycle whereby the sump water is freed of a substantial amount of concentrated salts and consumed treating chemicals while, at the same time, no fresh water and treating chemicals are allowed to enter the sump; thus preventing wastage of said water and chemicals. In addition, the amount of salts concentration that is sensed by a conductivity sensor 81 will activate relay 83 for a normal condition thereby allowing the blow-down phase to take place. However, for a low salts concentration level the blowdown phase will be prevented until the proper salts concentration is reached.
The make-up relays 86 and solenoid valve 24 remain deactivated until the water level drops to 88 at the end of the blow-down phase, when the magnet 52 closes switch 38 which deactivates the blow-down relays 82 and blow-down solenoid valve 20, while at the same time, actuates the make-up relay 86 and make-up solenoid valve 24, thereby simultaneously stopping the dumping of sump water into the sewer and allowing fresh water to enter the sump. At the same time the closing of switch 38 activates electrical circuits: to the acid and treating chemicals feed pumps 28 and 32 respectively, effecting the feeding of a predetermined amount of said acid and chemicals; to recorder 90; to make-up counter 92; and to excess make-up time timer 94.
The water level starts rising during the third or makeup phase which lasts until the original water level 78 and original treating chemical concentration have been reached whereupon the ring magnet 52 activates switch 34 which, in turn, de-activates make-up relay 86 and make-up solenoid valve 24, and stops the operation of acid and treating chemicals feed pumps 28 and 32 respectively, recorder 90, make-up counter 92, and exesss-time timer 94. This completes the operation cycle of the invention after having restored the amount of sump water and concentrations of treating chemicals to the original values thereof.
The invention also comprises a fourth magnetic reed switch 40 connected to an electrical alarm bell 96 through an alarm relay 98. Whenever the water level drops to an abnormally low level for reasons independent of the normal operation of the cooling tower, such as a sudden leakage of the sump, magnet 52 will activate switch 40 and through relay 98 will sound bell 96 warning of the abnormal state of the water sump. This alarm circuit can be shut off manually by means of switch 100. The pilot lamps herein enumerited function as follows: lamp 122 stays on as long as the system is in operation; lamp 124 stays on during the blow-down phase; lamp 126 stays on during the evaporation phase; lamp 128 stays on during the make-up phase; glowing of lamp 130 indicates that the make-up phase has run in excess of its normal time; and, finally, lamp 132 lights in addition to the operation of the electrical bell 96 indicating an abnormally low water level in the sump.
As it can be seen from the hereinbefore description, the present invention provides an efficient manner for the automatic and continuous control of water cooling towers, with substantial savings in the consumption of water and treating chemicals.
While the form of the invention herein described constitutes a preferred embodiment thereof, it is to be understood that the invention is not limited to this precise form of device and that various modifications and changes may be rendered therein without departing from the functioning or scope of the invention as hereinafter defined in the appended claims.
What is claimed is;
1. An automatic control system for controlling the water level and concentrations of treating chemicals and naturally occuring salts in water cooling towers having a cycle of blow-down, make-up, and termination phases; said system comprising a main control unit, auxiliary control apparatus comprising relays and solenoids operable with saidd main control unit, and a sump having said main control unit immersed therein; wherein said main control unit includes: an outer housing vertically disposed within said sump; an inner housing mounted within said outer housing; plurality of switching means positioned within said inner housing and electrically connected to said auxilliary control apparatus for blow-down, make-up, and termination phases; vertical adjustment means mounted within said inner housing for positioning said switching means; and bouyant switch actuator means slidably constrained in said outer housing so that said switching means will sequentially activate or de-activate said switching means as the water level in the sump varies in height.
2. The structure of claim 1 wherein said switching means includes four switches, a first switch operable at the uppermost space within said inner housing, a second switch located lower than said first switch, a third switch located still lower than said first switch and said second switch, and a fourth switch operable at the lowermost space within said inner housing.
3. The structure of claim 1 further comprising a vertically extending closure means having a plurality of vertically extending apertures, wherein said closure means is structured to a corresponding configuration of upper end of said inner housing, said closure means further comprised of a substantially resilient material to provide water-tight sealing of the upper end of said inner housing.
4. The structure of claim 3 wherein said vertical adjustment means is comprised of: a first, second, third, and fourth hollow plastic tube each slidably mounted within said apertures of said closure means, each of said tubes containing one of said switching means and corresponding electrical conductors connected to said switching means.
5. The structure of claim 1 wherein said swtich means is comprised of first, second, third, and fourth switches; and wherein said buoyant switch actuator means includes a magnet and a float supporting said magnet; and wherein said switches are magnetic reed switches that are activated or deactivated by the close proximity of a magnetic field and as the water level in the sump varies in height.
6. A control system as defined in claim 5 having a blow-down phase structure, said blow-down phase structure comprised of: said second magnetic reed switch for initiating the blow-down phase; a first relay connected to said first magnetic reed switch; a first solenoid valve controlled by said first relay, said first solenoid valve mounted on the sump for controlling the discharge of unwanted water and chemicals; and a conductivity sensor immersed in the sump and electrically connected to said first relay for preventing the blowdown phase if a system malfunction occurs that reduces the salts concentration in the sump.
7. A control system as defined in claim 5 having a make-up phase structure, said make-up phase structure comprised of: said third magnetic reed switch for initiating the make-up phase; a second relay connected to said third magnetic reed switch; and a second solenoid valve controlled by said second relay, said second solenoid valve mounted on the sump for controlling the addition of make-up water and chemicals.
8. A control system as defined in calim 7 having a cycle termination phase structure, said cycle termination phase structure comprised of: said first magnetic reed switch for terminating the make-up phase of the cycle; and a third relay connected to said first magnetic reed switch for shutting off said secnd solenoid valve.
9. A control system as defined in claim 5 having a low water indicator, said low water indicator comprising: said fourth magnetic reed switch; audible alarm means connected to said fourth magnetic reed which is activated when an abnormally low water level occurs; and visual alarm means connected to said fourth magnetic reed switch.
10. The structure of claim 1 wherein said buoyant switch actuator means is comprised of: an annular magnet encircling said inner housing; and an annular float fastened to said magnet, said float comprised of a plastic foam material for supporting said magnet in a buoyant condition.