WO1999037392A1

WO1999037392A1 - Method and apparatus for treating liquids

Info

Publication number: WO1999037392A1
Application number: PCT/US1998/026511
Authority: WO
Inventors: Robert H. Mausgrover
Original assignee: Ozone Systems, Ltd.
Priority date: 1998-01-21
Filing date: 1998-12-14
Publication date: 1999-07-29
Also published as: AU1822999A

Abstract

A method and apparatus for treating water using ozone. The apparatus diverts a portion of the untreated water from the main flow, diverts a portion of the diverted stream into several smaller streams, infuses ozone into the smaller streams, recombines the smaller streams with the diverted stream at a mixing venturi (20, 22), passes the recombined streams through a mixing chamber (154) having a partial vacuum, and then recombines the mixing chamber liq uid with the main flow. The mixing venturi (20, 22) mixes the streams and ozone and creates small bubbles of ozone which have a relatively large surface area for efficiently contacting and breaking down contaminants in the water. The mixing chamber (154) further mixes the streams and further reduces the size of the bubbles to further enhance the effectiveness of the ozone.

Description

METHOD AND APPARATUS FOR TREATING LIQUIDS

BACKGROUND OF THE INVENTION

The present invention relates to water treatment systems and, more particularly, to a method and apparatus utilizing ozone for purifying large volumes of water.

Water purification systems typically use chlorine or ozone as the purification agent.

Chlorine-based systems infuse chlorine into water. The water and chlorine mixture is allowed to

rest for at least thirty minutes so that the contaminants may be broken down by the chlorine. However, the use of chlorine as a purifier releases pollutants and tox.ns into the atmosphere. Additionally, the minimum contact time of thirty minutes required by chlorine to purify water severely limits the volume of water that a facility may treat.

Ozone-based systems infuse ozone into water. The treatment of water by ozone has been found to provide the benefits of chlorine treatment without the associated pollution and toxicity. Therefore, treatment systems which utilize ozone have become popular. Often, a portion of the water flow is diverted; ozone is infused into the diverted water at a venturi; and the infused diverted water is returned to the main flow in a mixing chamber to treat the main flow. Examples of such systems are illustrated in U.S. Patents 2,970,821 issued February 7, 1961 to Axt

and 5,075,016 issued December 24, 1991 to Barnes. Alternatively, a flow within a main pipe may

be infused with ozone at a venturi; the ozone is broken up and mixed with the water by a pressure

chamber in the pipe. An example of this system is illustrated in U.S. Patent 5,427,693 issued

June 27, 1995 to Mausgrover et al. In either method, the ozone bubbles remove or neutralize the contaminants within the water.

However, these treatment systems are limited in the volume of water which they are capable of purifying. After the ozone meets the main flow, sufficient time must be allowed for the ozone to become dispersed throughout the water to contact and remove the contaminants.

The required contact time of these systems does not result in the desired flow of water through the

system. The flow volume is additionally limited due to the half-life of ozone of 22 minutes; for longer

contact times, the ozone may begin to disassociate into oxygen prior to completion of the treatment.

SUMMARY OF THE INVENTION

The aforementioned problem is overcome by the present in\ ention wherein the ozone infused into the water is broken up into extremely small bubbles to increase the contact area of the bubbles and therefore both improve the flow rate and improve the effectiveness of the ozone. More

specifically, water is diverted from the inflow; ozone is infused into the diverted stream; the diverted stream is rejoined to the undiverted flow in a mixing venturi to produce an outflow stream. Mixing within the venturi results in improved mixing of the streams and a further reduction in the size of the bubbles.

In a second aspect of the invention, the outflow stream is further processed through

a mixing chamber. The mixing chamber is wider than the other flow pipes, and includes a partial

vacuum drawn on the fluid. This additional mixing further distributes the o -.one throughout the water and further reduces the size of the ozone bubbles. In fact, the bubbles created withing the mixing

chamber are so reduced in size that I call the mixture "milkwater" because it has such a high concentration of minute ozone bubbles that it appears "milky." This milkwater is a particularly

effective purifier due to the high concentration of ozone and large ratio of surface area to volume of ozone. The large surface area of these "micro bubbles" allows the ozone to quickly contact and break iown the contaminants. Part of my invention is the recognition that a limiting factor in the prior systems is the size of the ozone bubbles. The bubbles produced by at the infusion venturi are relatively large; therefore, the resulting surface area of ozone is insufficient to quickly contact large amounts of

contaminants. My invention addresses this shortcoming by taking additional steps to reduce the

ozone bubble size.

These and other objects, advantages, and features of the invention will be more readily understood and appreciated by reference to the detailed description of the preferred embodiment and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a top plan view of the manifold;

Fig. 2 is a top plan view of the mixing chamber;

Fig. 3 is a cross sectional view of a venturi and ozone tube taken along line III-III in Fig. 1;

Fig. 4 is a cross-sectional view of the mixing venturi and the outflow ends of the treatment pipes taken along line IV-IV in Fig. 1; and

Fig. 5 is a cross-sectional view of the mixing venturi and the outflow ends of the

treatment pipes taken along line V-V in Fig. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A manifold device according to a preferred embodiment of this invention is illustrated

in Figs. 1 and 2 and generally designated 10. For purposes of this disclosure, the present invention

is described in connection with the ozone treatment of a contaminated stream of water. However, the present invention is equally well suited for infusing a high concentrati-. α of any gas or liquid into

a greater volume of a second liquid. I. The Manifold

The manifold 10 is a relatively small device for treating contaminated water; its dimensions are approximately 1 and A feet by 4 feet by 6 feet. The manifold 10 has three distinct regions, namely an inlet area 20, a treatment area 30, and an outlet area 40.

The inlet area 20 includes an inlet pipe 50; in the preferred embodiment, the pipe 50

has a diameter of approximately 2 inches. However, dimensions of the pipe 50 are variable based upon the application of the manifold. The inflow end 52 of the inlet pipe 50 extends from the main water pipe (not shown) and diverts untreated water into the manifold through the action of a pump

(not shown), which is located near the inflow end 52 of the inlet pipe 50

The treatment area 30 includes two treatment pipes 60 and 62 and one flow-through

pipe 64 in the preferred embodiment. These pipes 60, 62, and 64 are connected to the inlet pipe 50 at its outflow end 65 by a y-junction 66. Of course, the treatment area 30 may have any number of treatment pipes. The diameter of the flow-through pipe 64 is preferably approximately 2 inches, although the diameter may change based upon the application of the manifold. A pressure valve 70,

preferably a ball valve, is located near the inflow end 72 of the flow-through pipe 64. This valve 70 allows the volume of water flowing through the various pipes 60, 62, and 64 to be controlled. The

treatment pipes 60 and 62 preferably have diameters of approximately 1 and ^XA inches based upon the

preferred embodiment. A valve 71 or 73, preferably a ball valve, is located near the inflow end 74

or 76 of each treatment pipe 60 or 62. These valves 71 and 73 allow one-half of the manifold to be

disengaged when smaller volumes of water are treated; they additionally control the amount of water diverted from the flow-through pipe 64. Each treatment pipe 60 or 62 has two additional ball valves

77 and 79 or 81 and 83 to control the pressure throughout the pipe 60 or 62.

Extending away from the inflow end 74 or 76 of each treatment pipe 60 or 62 at y- junction 68 or 69 are at least two infusion pipes 78 and 80 or 82 and 84 . Each infusion pipe 78, 80,

82 or 84 is approximately 3/4 inch in diameter, the diameter again being dependent on the application of the manifold. Valves 77 and 81 control the volume of water flowing through the various pipes 60, 78, and 80 or 62, 82, and 84. Additionally, each infusion pipe 78, 80, 82 or 84 has a pressure valve

86, 88, 90, or 92, preferably a ball valve, located near its inflow end 94, 96, 98, or 100 and contains

a venturi 102, 104, 106, or 108 located downstream from the pressure vah c 86, 88, 90, or 92. Each

venturi 102, 104, 106 or 108 is connected to an ozone generating means 110 by tubing 112, 114, 116, or 118. The infusion pipes 78, 80, 82, and 84 rejoin the treatment pipes 60 and 62 at mixing venturies 120 and 122 by t-j unctions 123 and 125. The outflow ends 124, 126, and 128 of the treatment pipes 60 and 62 and of the flow-through pipe 64 rejoin at a y-junction 130 at the outflow end 132 of the

treatment area 30.

The outlet area 40 includes an outlet pipe 150, which extends from the y-junction 130

located at the outflow end 132 of the treatment area 30; this pipe 150 preferably has a 2 inch diameter, the diameter again being dependent on the application of the manifold, and, at its outflow end 152, rejoins the main pipe (not shown). A mixing chamber 154 is located preferably at least 2

inches from the inflow end 156 of the outlet pipe 150. The mixing chamber 154 has a diameter of

at least 4 inches or double that of the outflow pipe 150 and a length of at least 18 inches to allow for

the desired mixing of the water streams. The mixing chamber 154 contains a pressure vacuum with a head space to agitate the streams and break up the bubbles of ozone. Additionally, the mixing chamber 154 is preferably located at least 2 inches from the outflow end 152 of the outlet pipe 150.

In an alternative embodiment (not shown), pressure gauges and control systems may be included with the pressure valves. Such systems provide for remote control and monitoring of the

pressure differentials in the pipes.

II. Operation of the Manifold

The manifold 10 is installed by tapping a main water pipe (not shown) and diverting

a portion of the contaminated flow into the manifold 10. The volume of water to be diverted depends on the application and the level of contamination of the water. The pump (not shown) draws

untreated water from the main pipe (not shown) into the inlet pipe 50, and the water flows toward the treatment area 30.

In the treatment area 30, a portion of the contaminated water is diverted at a y- junction 66 into the treatment pipes 60 and 62; the volume of water to be diverted is controlled by valves 70, 71, and 73 and depends on the application and the level of contamination in the water. The

remainder of the water continues through the flow-through pipe 64. For small treatment systems, one

treatment pipe 60 or 62 may be disengaged by closing valve 71 or 73.

In the treatment pipe 60 or 62, an additional portion of the contaminated water is

diverted into the infusion pipes 78 and 80 or 82 and 84 at additional y-junctions 68 or 69. The pressure valves 86, 88, 90 or 92 may be used to raise or lower the pressure of the water and thus

control the pressure differentials across the venturies 102, 104, 106, or 108. Preferably, the pressure in the infusion pipes 78, 80, 82 or 84 is approximately 10-14 pounds per square inch (psi). In the

preferred embodiment, a pressure of 12 psi is used. Of course, the pressure differential required across the venturies 102, 104, 106, or 108 is dependent on the gas or liquid to be infused and the liquid flowing through the manifold.

As seen in Fig. 3 , as the contaminated water flows through the venturies 102, 104, 106

or 108, ozone is infused into the water through tubing 112, 114, 116, c 118 which connects the

manifold 10 to the ozone generating means 110. The volume of ozone to be introduced depends on the contaminants present in the water and the volume of water to be treated. Obviously, other means for introducing the ozone into the water may be used. The combination of heightened pressure from the valves 86, 88, 90 or 92 and the inherent mixing action of the venturies 102, 104, 106, or 108

cause the ozone to be broken into a multitude of bubbles. This high concentration of bubbles creates a large surface area of ozone which, as the ozone contacts the contaminants in the water, breaks the

contaminants down and purifies the water.

The valves 86, 88, 90, or 92 and venturies 102, 104, 106, or 108 work in conjunction with each other. Venturies inherently create pressure differentials as a function of their shape.

However, the pressure differential created solely by a venturi is insufficient to create small bubbles

of ozone as the ozone is introduced into the water. The pressure valves 86, 88, 90, and 92 allow the pressure to be controlled to create a larger differential which produces a multitude of smaller bubbles.

In addition, the pressure differential draws the ozone into the infusion pipes 78, 80, 82, or 84.

A check valve (not shown) may be installed in the tubing 112, 114, 116, and 118 to

ϋtop the flow of ozone if the manifold 10 malfunctions. The check valve (not shown) prevents the water and ozone from backing up through the tubing and into the ozone generator 110.

As seen in Figs. 4 and 5, the water and ozone mixture passes through the infusion

pipes 78, 80, 82, and 84 which reconnect into the treatment pipes 60 or 62 at mixing venturies 120

7 or 122 or other mixing means by the t-junctions 123 or 125. These venturies 120 and 122 further agitate and mix the water coming from the infusion pipes 78 and 80 or 82 and 84 with the water which has passed through the treatment pipes 60 or 62. Additionally, the mixing action of the venturies 120 and 122 further reduces the dimensions of the ozone bubbles

This treated water then continues through the treatment pipes 60 and 62 and, at a y- junction 130, combines with the contaminated water coming from the flow-through pipe 64. This

stream of contaminated water, purified water, and ozone bubbles flows into the outlet pipe 150. The

mixing chamber 154 allows these treated and untreated streams to mix thoroughly with the bubbles.

In addition, the pressure vacuum in the mixing chamber 154 causes the streams and ozone bubbles to become thoroughly agitated. This agitation greatly reduces the size of the bubbles and creates micro bubbles. The actual number of bubbles may be quadrupled by the action of the mixing chamber 154. At this point, the water has such a high concentration of micro bubbles that it appears milky. This milkwater is particularly effective at removing contaminants from the water due

to the high concentration and large surface area of the micro bubbles. The large surface area allows the ozone to quickly contact and break down any contaminants present.

As this purified water flows out of the outflow end 152 of the outlet pipe 150, it and

the accompanying micro bubbles mix with the contaminated water in the main pipe (not shown). This

mixture must have sufficient contact time for the micro bubbles to mix with and purify the

contaminated water in the main pipe. If there is an insufficient length of main pipe (not shown) through which the water flows remaining to provide the contact time, the water and ozone mixture may be placed in holding tanks (not shown) for the remainder of the time. The minimum contact time for purification depends on the contaminants present in the water. Raw sewage requires approximately 6-8 minutes of contact time due to its heavy turbidity. However, grey water, i.e. stream or river water which visually appears clean but does contain bacteria

and/or viruses, requires a minimum contact time of approximately 4 seconds at .5 parts per million (ppm) of ozone. The minimal contact time required to purify the water is a function of the micro

bubbles of ozone created by the mixing chamber 154. The milkwater produced by the mixing chamber 154 quickly removes contaminants due to the large surface area of ozone.

The above descriptions are those of a preferred embodiment of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalence.

Claims

The embodiments of the invention in which an exclusiv property or privilege is

claimed are defined as follows:

-1-

An apparatus for infusing a gas into a liquid comprising: a first pipe through which the liquid flows; a second pipe having an inflow end in fluid communication with said first pipe and an outflow end; infusion means for infusing the gas into the liquid flowing through said second pipe; and

a mixing venturi within said first pipe, said outflow end of said second pipe being in fluid communication with said venturi, whereby the liquid infused with the gas in said second pipe is

mixed with the liquid in said first pipe in said mixing venturi.

-2-

The apparatus of claim 1 further comprising:

an outlet pipe in fluid communication with a plurality of said first pipes, said outlet pipe including a mixing chamber having at least a partial vacuum whereby said flows from said first pipes are agitated and the gas is broken into a multitude of small bubbles.

-3-

The apparatus of claim 2 wherein said chamber is located at least two inches from an

outflow end of said first pipe.

10 -4-

The apparatus of claim 1 wherein said infusion means includes a venturi having a controlled pressure.

-5-

An apparatus for mixing a gas into a liquid comprising: a main pipe through which the liquid flows;

a treatment pipe in fluid communication with said main pipe, said treatment pipe diverting a portion of the liquid flowing within said main pipe, said treatment pipe including an outflow end;

an infusion pipe in fluid communication with said treatment pipe, said infusion pipe diverting a portion of the liquid flowing within said treatment pipe, said infusion pipe including introducing means for introducing the gas into the liquid, said infusion pipe further including an

outflow end; mixing means for mixing liquid exiting said outlet end of said infusion pipe with liquid

flowing within said treatment pipe; a mixing chamber connected to said outflow end of said treatment pipe and drawing

a partial vacuum on said outflow end of said treatment pipe wherein the gas is broken into smaller bubbles; and

junction means for recombining the liquid exiting said mixing chamber with the liquid within said main pipe.

-6-

The apparatus of claim 5 wherein said mixing means includes a mixing venturi.

11 -7-

The apparatus of claim 5 wherein said introducing means includes a venturi having a controlled pressure.

-8-

An apparatus for infusing a gas into a greater volume of a liquid comprising: at least one first pipe through which the liquid flows;

at least one second pipe having an inflow end in fluid coni'Tiunication with said first

pipe and having an outflow end in fluid communication with said first pipe and which diverts a portion

of the liquid from said first pipe, said second pipe including a venturi having a controlled pressure to introduce the gas; and a chamber having at least a partial vacuum and in fluid communication with an outflow end of said first pipe whereby the gas and the liquid are agitated and the gas is broken into a multitude of small bubbles.

-9-

The apparatus of claim 8 further comprising a mixing means for mixing the flows of the liquid within said first pipe, said outflow end of said second pipe in fluid communication with said mixing means.

-10-

The apparatus of claim 9 wherein said mixing means includes a venturi.

-11-

A method for combining a gas with a liquid comprising the steps of:

12 diverting a portion of a flow of the liquid to create a diverted flow and leaving an undiverted flow; introducing the gas into the diverted flow; rejoining the diverted and undiverted flows creating a rejoined stream; and

passing the rejoined stream through a chamber having at least a partial vacuum, whereby the rejoined stream is agitated and the gas is broken into smaller bubbles.

-12-

The method of claim 11 further comprising the steps of:

creating a first flow by diverting a portion of the liquid from a main flow prior to the diverting step;

creating a second flow by diverting a portion of the liquid from the first flow prior to the diverting step;

said diverting step includes diverting a portion of said second flow; and

said rejoining step includes rejoining a plurality of the diverted flows.

-13-

The method of claim 12 further comprising the step of:

rejoining the diverted flow and the second diverted flow in a mixing means for mixing the flows prior to said rejoining step.

-14-

The method of claim 13 wherein said mixing means includes a venturi.

13 -15-

The method of claim 11 wherein said introducing step includes introducing the gas at

a venturi having a controlled pressure whereby the gas is mixed with the iquid.

-16-

A method for combining a gas with a liquid comprising the steps of: diverting a portion of a flow of the liquid;

introducing the gas into the diverted flow; and rejoining the flows at a mixing venturi, whereby the gas is distributed within the rejoined flow.

-17-

The method of claim 16 further comprising the steps of:

creating a first flow by diverting a portion of the liquid fro 1 a main flow prior to the diverting step;

said diverting step includes diverting a portion of said second flow; and

said rejoining step includes re-combining the diverted flow and the second flow at said

mixing venturi to create a re-combined flow.

-18-

The method of claim 17 further comprising the step of:

14 returning the re-combined flows to the first flow to be mixed in a mixing chamber having at least a partial vacuum whereby the flows are agitated and the gas is broken into a multitude of small bubbles.

-19-

The method of claim 16 wherein said introducing step includes introducing the gas at a venturi with a controlled pressure whereby the gas is mixed with the liquid.

-20-

A method for combining a gas with a greater volume of a li uid comprising the steps of:

diverting a portion of a main flow of the liquid to create a first diverted flow; diverting a portion of the first diverted flow to create a second diverted flow; diverting a portion of the second diverted flow to create a third diverted flow; introducing the gas into the third diverted flow; rejoining at least the second and third diverted flows in a mixing means for mixing the

flows; and rejoining the flows in a chamber having at least a partial vacuum whereby the flows

are agitated and the gas is broken into a multitude of small bubbles.

-21-

The method of claim 20 wherein said introducing step includes introducing the gas in

a venturi having a controlled pressure whereby the gas is mixed with the liquid.

-22-

The method of claim 20 wherein said mixing means includes a venturi.

15