Closed loop water treating system and method

A system for treating water includes an aerator or degasifier that is fluidly connected to a blower that moves gases released from the water cascading down in the aerator over slat trays or plastic packing media. The released gases enter a gas scrubber and are treated with an iron salt solution that removes undesirable gases and that form a sludge that is removed from the scrubber. The residual gases, mostly nitrogen, argon, and other minor gases found in ambient air, flow into the aerator. In some instances, the gas scrubber also includes, in addition to the iron salt solution treating equipment, equipment for treating the released gases with caustic soda solution.

BACKGROUND OF THE INVENTION 
This invention pertains to water treating and purification systems and, 
more particularly, to a closed loop water treating system. 
During the past few years, clean, pure water for personal consumption, and 
for industrial purposes has become scarcer than ever before. Waste water 
and effluent from industrial plants are contaminating underground waters, 
and the polluted streams are flowing into reservoirs from which potable 
water is drawn. It is now mandatory that water treating systems be set up 
to clean up these impure and hazardous water situations. 
SUMMARY OF THE INVENTION 
A water treating system in accordance with the invention comprises a closed 
loop configuration of apparatus that includes: an aerator or degasifier 
that receives contaminated water; slat trays or plastic media within the 
degasifier that distribute the water over the packing media; and an air 
resistor at the bottom of the degasifier. 
The closed loop water treating system also includes a gas scrubber having 
sprays which emit a gas treating iron salt solution. The salt solution 
mixes and reacts with incoming gaseous fluid flowing from the aerator or 
degasifier 13 into the scrubber 15 and removes undesireable gases from the 
incoming gaseous fluid by forming a sludge which falls as a precipitate 
into a sludge collector. High and low sensors determine the need for more 
chemical solution in the system; and air relief ports conduct the treated 
gas to the bottom zone of the scrubber from which it flows into the 
aerator or degasifier. 
In some instances, the water treating system of the present invention 
includes an aerator or degasifier like that shown in FIGS. 1 and 2, and a 
gas scrubber wherein both iron salt solution and caustic are used to treat 
gases flowing from the aerator or degasifier. 
For a further understanding of the present invention, and for features and 
advantages thereof, reference may be made to the following description of 
the invention taken in conjunction with the drawings.

DETAILED DESCRIPTION 
Referring to FIG. 1, a closed loop water treating system 11, in accordance 
with the invention, includes an aerator or degasifier unit 13 and a 
scrubber unit 15. 
The aerator or degasifier unit 13 comprises a closed vertical structure 
including an envelope 17 having a top 18 and bottom 20. The envelope 17 is 
supported on the ground or other supporting surface 19. The aerator or 
degasifier unit 13 also includes a water inlet conduit 22 that carries 
water into an internal header 21 located near the top of the aerator or 
degasifier unit 13. A plurality of spray heads 23 are mounted into the 
header 21. Beneath the water inlet header 21 are a plurality of 
conventional slat trays or plastic packing media 25 mounted in 
conventional manner to a molded fiber glass frame supporting structure 27 
within the envelope 17. The slat trays or plastic packing media 25 are 
spaced apart vertically in conventional manner, and are so constructed and 
arranged that water is distributed over the surface of the trays or media 
25 as it cascades downward within the envelope 17, and gases entrained in 
the water are liberated from the solute water according to the respective 
partial pressure of the gases. 
Extending into the envelope 17, near the bottom 20, is a gas conduit 29 
that is so constructed and arranged that water cascading downward does not 
impede the flow of gas from the scrubber unit 15 into the envelope 17. The 
inner end portion of the gas conduit 29 is shaped, as at 31, to direct the 
water flow away from entering the conduit 29. 
The bottom of the aerator or degasifier unit 13 is provided with an air 
resistor 33 and a downcomer 35 for product water. The air resistor 33 and 
the downcomer 35 are shown in FIG. 2 and are more particularly described 
hereinafter. 
Disposed atop the aerator or degasifier unit 13 is a conventional demister 
37 that prevents excessive loss of moisture from the aerator or degasifier 
unit 13. 
Connected to the demister unit 37 is an exhaust gas conduit 39 that 
connects to the inlet end of a tube axial or other type of blower 41 that 
is suitably mounted to a support structure 43. The blower 41 is powered by 
a conventional electric motor (not shown) and is so arranged and 
constructed that gas is withdrawn from the aerator or degasifier unit 13, 
through the demister 37, and is urged in the direction of the arrows A 
through the blower 41 toward the gas scrubber unit 15. Conduit 44 connects 
the exhaust side of the blower 41 to the inlet conduit 45 of the gas 
scrubber unit 15. 
Associated with the gas conduit 39 is an air make-up conduit 40 located 
about where shown in FIG. 1. The flow of ambient air in conduit 40 is 
controlled by means of vacuum sensors (not shown) that determine when 
additional gaseous fluid is required to keep the system full at all times. 
The gas scrubber unit 15 comprises a closed vertical structure including an 
envelope 47 having a top 49 and bottom 51. The scrubber unit 15, like the 
aerator or degasifier unit 13, is supported on the ground or other 
suitable support base 53. 
Beneath the top 49, within the envelope 47, is a wash header 59 to which 
are mounted a plurality of spray heads 61. 
The scrubber unit 15 contains a plurality of vertically arranged 
spaced-apart slat trays or plastic packing media 55 of conventional type 
that are supported by side frame structure 57, and that are disposed 
beneath the spray heads 61. The slat trays or plastic packing media 55 and 
the frame structure 57 are made, preferably, of fiber glass or other 
suitable plastic material. 
Beneath the lowermost slat tray or plastic packing media 55, is a dome-like 
shroud 63 that is suspended in position by support arms 65 fixed to the 
envelope 47 and to the shroud 63. 
Beneath the shroud, about where shown in FIG. 1, is a conical sludge 
collector 67 that is fitted with a drain pipe 69 that extends through the 
envelope 47. 
A plurality of vertically arranged tubular gaseous relief conduits 71 are 
disposed about where shown, and they are so constructed and arranged that 
the tops terminate within the shroud 63 and the bottoms below the lower 
edge of the sludge collector 67. 
Beneath the sludge collector 67 and the drain pipe 69 is a hood 73 covering 
a conventional dewaterer unit 75. The hood is connected fluidly to the gas 
conduit 29 outside the envelope 47. 
The wash header 59 is connected to a conduit 79 outside the envelope 47, 
that carries an iron salt solution from a recirculating pump 77 to the 
wash header 59. 
In the bottom of the aerator or degasifier 13 is an air resistor 33, shown 
in FIG. 2, that comprises a hood 11 made, preferably, of fiber glass or 
other plastic material, that has a plurality of ports 83 in the bottom 
edge to permit water to flow into the hood. The hood 81 covers the product 
water drain pipe 35, and there is created a space between the top of the 
product water drain pipe and the top of the hood 81. 
When the water treating system comprising the apparatus shown in FIGS. 1 
and 2 is operational, water flows into the aerator or degasifier 13 in the 
direction of the arrow B through conduit 22 into the wash header 21. The 
water flows from the wash header 21 through the spray heads 23 onto the 
slat trays or plastic packing media 25 and downward in the envelope 17. 
The impingement action of the water falling from tray to tray, or onto the 
control film process with the packed media, causes the release of 
entrained gases, such as hydrogen sulfide, carbon dioxide, methane, if 
present in the water, and other ideal gases, if present, according to the 
partial pressure of the gases, in a conventional manner. 
The gases liberated in the aerator or degasifier 13 are drawn upwards by 
the action of the axial blower or other type of blower 41, but the product 
water, free of such gases, collects in the bottom of the aerator or 
degasifier 13 and enters the air resistor 33. The water flows through the 
ports 83 and creates therein a minimum water column measured by the 
dimension G in inches. The dimension G will be great enough to maintain a 
water column that is greater than the static pressure within the envelope 
17. Wherefore, gases liberated in the envelope 17 do not enter the air 
resistor 33. The liberated gases must, then, flow upward in the aerator or 
degasifier 13 through the demister 37 and into the conduit 39. 
In the air resistor 33 the dimensions indicated by the letters D,E,F are 
determined by the volume of water to be treated. The size and number of 
the ports 83 are determined by both the flow rate and the water column G 
in inches needed to prevent the liberated gases from entering the product 
water drain pipe 35. 
The liberated gases flow from the demister 37 into the tube axial or other 
type of blower 41, through conduit 44 and conduit 45 into the scrubber 
unit 15. 
The gases flow downward in the scrubber unit 15 and are first treated with 
an iron salt solution emitted by the spray heads 61. The gaseous fluid 
reacts with the iron salt solution flowing downward over the slat trays or 
plastic packing media, and a sludge is created that precipitates onto the 
shroud 63. Thence the sludge flows into the sludge collector 67 and from 
the sludge collector 67 through conduit 69 out of the scrubber 15 to 
another place for disposal in a conventional manner. 
The residual gaseous fluid in the bottom zone of the scrubber 15 flows into 
a hood 73, through a conventional dewaterer unit 75, and into conduit 29 
leading to the bottom zone of the aerator or degasifier 13. The residual 
gaseous fluid in the bottom of the scrubber is free of contaminant gases 
except nitrogen, argon and the other minor gases found in air that is 
entrained in water entering the aerator or degasifier 13. The gaseous 
fluid flows upward in the aerator or degasifier and mixes with the gases 
liberated from water entering the aerator or degasifier. 
Thus, the water treating system illustrated in FIGS. 1 and 2, constitute a 
closed loop system from which no obnoxious odors are released to the 
atmosphere. 
Referring to FIG. 3, another form of gas scrubber 115 includes a closed 
vertical structure or envelope 147 having a top 149 and a bottom 151. The 
scrubber 115, like the scrubber 15 of FIG. 1, is fluidly connected and 
operates with an aerator or degasifier 13 like that shown in FIG. 1 and 
described hereinbefore. 
The scrubber 115 is supported on the ground 153, or other suitable support 
medium. Beneath the top 149, within the envelope 147, is a wash header 159 
to which are mounted a plurality of spaced-apart spray heads 161. Beneath 
the spray heads 161 is a first arrangement of a plurality of vertically 
spaced-apart slat trays or plastic packing media 155 of conventional 
construction that are disposed in the upper portion of the envelope 147. 
These slat trays or plastic packing media 155 are supported by side frame 
structure 157 within the envelope 147. Preferably, the slat trays or 
plastic packing media 155 and the side frame structure 157 are molded 
fiber glass or other suitable plastic material. 
Beneath the lowermost slat tray 155 is a dome-like shroud 163 that is 
suspended in position by a plurality of support arms 165 fixed to the 
envelope 147 and to the shroud 163. 
Beneath the shroud 163, about where shown in FIG. 3, is a conical sludge 
collector 167 that is fitted with a drain pipe 169 that extends outwardly 
through the envelope. The sludge collector 167 is supported around its 
perimeter by making contact with the envelope 147. 
A plurality of vertically arranged tubular gaseous relief conduits 171 are 
disposed about where shown and they are so arranged and constructed that 
the tops thereof terminate within the shroud while the bottoms are located 
just below the sludge collector 167. 
Beneath the drain pipe 169 is another wash header 259 to which are mounted 
a plurality of spray heads 261. 
Beneath the spray heads 261 is a second arrangement of vertically 
spaced-apart slat trays or plastic packing media 255, of conventional 
type, that are disposed in the lower portion of the envelope 147. 
Preferably, the slat trays 255 and the side frame structure 157 are molded 
fiber glass, or other suitable plastic material. 
Beneath the lowermost slat tray 255 is another dome-like shroud 263 that is 
suspended in position by a plurality of support arms 265 fixed to the 
envelope 147 and to the shroud 263. 
Beneath the shroud 263, about where shown in FIG. 3, is another conical 
sludge collector 267 that is fitted with a drain pipe 269 that extends 
through the envelope 147. Like the shroud 163, the shroud 263 is also 
supported around its perimeter by being in contact with the envelope 147. 
A plurality of gaseous relief conduits 271 are disposed about where shown 
and they are so arranged and constructed that the tops thereof terminate 
within the shroud 263 while the bottom of each conduit 271 terminates just 
below the conical sludge collector 267. 
Outside the upper portion of the envelope 147 there is a conduit 171 which 
fluidly connects the wash header 159 to a pump 173 that recirculates a 
ferrous sulfate solution, originating from a storage tank (not shown) 
through a conduit 175 into the conduit 171. The pump 173 is also connected 
to a conduit 177 that extends through the envelope 147 into the space 
beneath the shroud 163. 
In like manner, outside the envelope 147, near the bottom thereof, another 
conduit 271 connects the wash header 259 to a pump 273 that recirculates 
caustic solution, as required, that flows from a caustic solution supply 
tank (not shown). The caustic solution flows in conduit 275 into conduit 
271. The pump 273 is also connected to conduit 277 that extends through 
the envelope 147 into the space beneath the shroud 263. 
As shown in FIG. 3, the residual gaseous fluid in the lower zone of the 
scrubber 115 flows through the gas collector conduit 279 and conduit 281 
extending outside the envelope 147. The conduit 279 carries the residual 
gaseous fluid to the bottom zone of the degasifier 13 under the influence 
of the axial blower 141 or other type of blower. Gaseous fluid flows 
through the blower 141 through conduit 144 into the top of the scrubber 
115 in the direction of the arrow Y. 
Now, then, when a water treating system that includes an aerator or 
degasifier 13, like that shown in FIGS. 1 and 2, and a gas scrubber 115, 
like that shown in FIG. 3, is operational, water flows into the aerator or 
degasifier 13 and product water flows therefrom through the product water 
conduit 35 as described herein previously. Liberated gases, under the 
influence of the blower 141 flow in conduit 283 through the blower 141 and 
conduit 143 into the scrubber 115. 
The gaseous fluid is treated in the upper half portion of the scrubber 115 
with an iron salt solution from the spray heads 161. The gases and the 
iron salt solution flow over the slat trays or plastic packing media 255 
and impinge on the upper shroud 163. A sludge precipitate that forms in 
the scrubber 115 collects in the sludge collector 167, and is withdrawn 
therefrom through conduit 169 for disposal elsewhere. 
Any carbon dioxide arising from the sludge, or being present in the 
scrubber 115, enters the gaseous relief conduits 171, and flows downward 
in the scrubber under the influence of the blower 141. In the lower 
portion of the scrubber 115, the carbon dioxide is treated with a solution 
of caustic soda from spray heads 261. The reaction of the carbon dioxide 
with the caustic soda solution produces a sludge that precipitates onto 
the shroud 263 and is collected in the sludge collector 267 from which it 
is withdrawn through conduit 269 for subsequent disposal elsewhere. 
Persons skilled in the art will recognize that the gaseous fluid in the 
bottom zone of the scrubber 115 is, by now, free of hydrogen sulfide, if 
present initially; oxygen, if present initially; carbon dioxide, if 
present initially. Wherefore, the residual gaseous fluid now comprises 
nitrogen, argon, and the other minor gases found in ambient air. Such 
residual gaseous fluid flows into the lower zone of the aerator or 
degasifier 13 and is recycled with the gases liberated from the incoming 
water entering and being treated in the aerator or degasifier 13. 
From the foregoing description of embodiments of the present invention, 
persons skilled in the art will recognize many features and advantages 
thereof, among which the following are significant: 
That there are no exhaust gases that pollute the atmosphere; 
That no obnoxious odors are released to the atmosphere; 
That there is no dissolved oxygen in the product water so that equipment 
required to use pure water or nearly pure water like steam boilers, pumps, 
potable water systems, and the like, has a much greater service life, 
since the water is free of corrosive gases; 
That a proper proportion of iron salts in the system is controlled by 
sensors; 
That the air resistor prevents released gases from being carried with the 
product water from the aerator or degasifier; 
That any required make-up water needed to keep the system full at all times 
enters through conduit 40 under control of automatic valving (not shown); 
and 
That the system of the invention pretreats water and eliminates oxygen from 
contacting the treated water and, therefore; does not cause dissolved 
materials to precipitate and foul other systems. 
Although the invention has been described in relation to the embodiments 
shown in the drawings, it is understood that other modifications may be 
made therein without departing from the spirit of the invention as defined 
by the scope of the appended claims.