CA1333200C - Aeration header module - Google Patents

Abstract

An aeration and mixing jet header for use in the construction of water and wastewater treatment system is disclosed.
The header has a body provided with a cylindrical waste water passage, a cylindrical air passage and a wastewater outlet conduit extending laterally of the wastewater passage. An airfeed device connects the air passage and the wastewater passage. This device is intended to allow air to flow from the air passage and be injected into the waste water flowing through the outlet conduit. More specifically, this invention describes an optimum construction method for such jet headers based on modularity principe allowing for full inspection and compliance to fiber glass official con-struction codes.

Description

1333~00 BACKGROUND OF THE INVENTION

Field of the invention:

The present invention relates generally to the construction of systems for the treatment of wastewater in an aeration basin or lagoon. More particularly, the invention concerns a header module for use in the operation of such systems as part of a component.
Description of the prior art:

In a system of this type, such as the one described in Applicant's application in Canada No. 561.448 of March 15, 1988, a header spreads across the basin; the header being a piping installation provided with means creating aerated water jets discharging into the basin and causing circulation of the wastewater in an endless path and simultaneously aerating it. A dam is formed across the path to allow sludge to settle at the bottom of the basin. A
pumping station, built into a well, allows operation of the system to feed the header with water drawn from the top of the body of wastewater in the basin; aerates the water as it is discharged into the basin; draws out sludge that has accumulated upstream of the dam and generally circulates water to clean the piping installation.
By the term "wastewater", as used herein, should be understood mainly waste matter from domestic, commercial and industrial establishments carried off in sewers and having a high water content. Other types of liquid mixtures may also be treated by the system.
The construction of a header in such a system is a time-consuming and therefore expensive operation and it is 1333~00 an object of this invention to propose a standardizable aeration header module suitable to be factory made at low cost and to which water and air pipes can easily be connected, in situ, to thus reduce the installation costs.
The header modules can also of course be "shop connected"
prior to shipment.

SUMMARY OF THE INVENTION

The invention as broadly disclosed hereinafter is concerned with an aeration header module of the type comprising:
a cylindrical wastewater passage;
a cylindrical air passage adjacent to the wastewater S passage;
a wastewater outlet conduit extending laterally from the wastewater passage; and air feed means which connect the air passage and the wastewater outlet conduit, these means including an air conduit joining the air passage and the wastewater outlet conduit and a venturi cone located in the wastewater outlet conduit, and being constructed to allow air to flow by gravity entrainment, slight negative pressure or under pressure, from the air passage and be injected into, and mixed with the wastewater flowing in the wastewater conduit.
According to a first embodiment of the invention which is disclosed hereinafter but not claimed and is called "split modular jet assembly", the module includes a body which is essentially flat and through which the air and wastewater passages extend perpendicularly. The air conduit extend within the body parallel to the body outer faces, as does the wastewater outlet conduit which opens out of the body.
For ease in manufacturing, the body is preferably A

1333~.00 made up of two mirror-image but otherwise identical planar portions flatly lying one against the other with the passages and the conduits being in half sections in the two body portions and respectively overlapping.
According to a second embodiment of the invention which is disclosed and claimed hereinafter and is called "monoblock modular jet assembly", the wastewater passage is defined by a first cylinder; the air passage is defined by a second cylinder; the wastewater outlet conduit is defined by a third cylinder which is connected to the first cylinder to extend laterally therefrom; and the air conduit is defined by a fourth cylinder joining the second and third cylinders laterally thereof. Once again, a venturi cone is located.
This cone has a wide base solid with the third cylinder upstream of the fourth cylinder and extending beneath the fourth cylinder.
Thus, the invention as it is claimed hereinaifter is directed to a jet aeration and mixing header for use in a water or wastewater treatment system, said header comprising:
- a first cylinder defining a water passage, - a second cylinder extending parallel to the first cylinder and defining an air passage;
- at least one water outlet conduit connected to said first cylinder and laterally extending therefrom the allow water to be expelled out of said water passage;
- at least one air-feed cylinder, each air-feed cylinder connecting the second cylinder to one of said at least one outlet conduit at a given point of connection along said one outlet conduit to allow air to be delivered from said air passage into said water flowing through said one outlet conduit; and - a venturi cone mounted in each outlet conduit, said cone having a wide inlet extending across the outlet conduit - ,~
, , 13~37JO~

upstream said point of connection of the air-feed cylinder, and a narrow outlet extending centrally in said outlet conduit downstream said point of connection to allow, in use, air to be drawn from the air passage and mixed with the water expelled through the narrow outlet of said cone;
characterized in that:
- each water outlet conduit is made up of a nipple solid with an projecting from said first cylinder and of a T-shaped coupling having a stem section and a transverse bar section, said transverse bar section being connected at one end to said nipple to form therewith said outlet conduit with said stem section acting as said point of connection for the air-feed cylinder connected to said outlet conduit.
According to a preferred embodiment, the header further comprises a nozzle connected to each transverse bar section forming part of one of said at least one outlet conduit, opposite to the one end of said transve~se bar section connected to said nipple, said nozzle having an inlet having an internal diameter substantially identical to the diameter of said transverse bar, and an outlet of smaller diameter.
According to another preferred embodiment, the header comprises sockets integral to some of its structural elements to interconnect all of said elements by mere fitting.

General comments regarding the invention:

There are, at the present time, three types of jet aeration systems to be found on the market.
A first system may be said to be of the self-suction type where the jets are designed to draw the air or another gas at atmospheric pressure without any means of pressurization other than the dynamic pressure of the 3a -1333?,00 flowing wastewater. The specific geometry consists in discharging a water jet into a venturi tube (ejector principle) entraining and shearing air bubbles at its discharge.
In a second system, the jets are fed by air or another gas under pressure and by water under pressure. The specific geometry consists in discharging a water jet into a short venturi tube shearing air bubbles at its discharge.

/
!
/

- 3b -1333~,00 There is also a self-suction and/or single jet mixing system wherein the jets are designed to mix a liquid tank content using the tank liquid as pressure source to feed the jet. The entrained or secondary fluid can be in gas or liquid form depending on the kind of mixing desired or whether or nor a chemical reaction is also to take place (ex. neutralization system/equalization tank, floculation tank etc.).
These types of jet systems utilize a common source of pressurized wastewater flowing in a plenum piping system.
The above first two types of systems can also utilize a common air piping source if the individual air pipe cannot be connected directly from the water surface for such reasons as ice protection, esthetics, the life expectancy of the e~li~nt or design reasons. If there are nosuch reasons, then the air intake piping can be simplified especially for the self-suction type of jet aeration system.
In fact, the air piping can than be reduced to an individual short intake pipe having quite a small diameter instead of a main air header running parallel to the main wastewater header. In such cases, the only pipe header necessary is the water pipe which can be installed parallel to the water surface in the basin and very close to the water level. The elevation of this water header can vary indefinitely from deeper submergence up to an above elevation over the water surface.
The third type can consist of a single or double nozzle mounted on the pipe header with or without any parallel piping.
The present invention is meant to apply to all these different applications.
The construction of a jet-type aeration header resides basically in attaching a primary reducer cone to a pressurized water header to produce a water jet flowing concentrically through a secondary long or short venturi 1333~00 cone to provide a gas bubble shearing effect at its final discharge into the water basin. A special concern is to ensure efficient hydraulic conditions and to provide very smooth internal surfaces to obtain a trouble-free operation.
These two major constructional requirements can be achieved by using piping made of fiberglass-reinforced plastic material (F.R.P.) because of its recognized properties of smoothness, corrosion resistance but also because an aeration jet header involves many molded pieces to be fitted together and attached to a round pipe. Because of necessary intensive manual work, the quality of the jet header construction can vary a lot like standard F.R.P.
construction as well.
Gouvernment construction agencies have recognized these difficulties with F.R.P. material of which the structure consists in fibers glued together by resin.
Specific F.R.P. constructional codes are now available to ensure a minimum quality level. These codes are as follows:
- Canadian standard for F.R.P. corrosion resistant equipment CGSB 41GP22 rev./84.
- National Bureau of Standards PS15-69 for United States.
For different reasons (mainly construction costs, difficulties in adapting the jet construction to these codes etc...) no aeration jet header construction on the market today really meets those well established constructional requirements.
The present invention is a new header construction capable of complying with all those quality constructional codes.
The essence of the present invention is to provide a modular construction suitable to attach any F.R.P. type conical jets to a F.R.P. pipe without requiring to take exceptions of the 41GP22 or PS15-69 codes such as:

1333~.00 - drilling large orifices on an existing F.R.P. pipe to allow for jet positioning. This pipe structure is then seriously altered as teh fibers are cut.
The pipe can no longer meet the construction requirements even if some reinforcement fiber layers are locally added around the nozzles;
- using the filament wound pipe construction method and altering the angle of orientation of the fibers when joing around the nozzles while the jet header is being manufactured directly on the pipe mandrel with prefabricated jets already positioned on this mandrel. For best pipe structure, this angle must be uniform all along the pipe, oriented at 55 + 2 degrees maximum. The orientation degree may varies for some construction but it must always remain constant within +2 degrees maximum.
The above represent two major construction deficiencies currently not solved by North American manufacturers.
Furthermore, recognizing the importance of quality control for this type of construction, no manufacturer can duly internally inspect the F.R.P. jet header. Such an inspection is impossible because the size of the pipe is normally too small for anyone to crawl into. Yet, such an inspection is very important to ensure that all manual work was performed properly with no sharp edges or pretrusions on all internal surface and particularly at the jet connections. The pos-sibility of a complete inspection is of the utmost importance ,o be in a position to control clogging problems associated with poor jet connection construction. In fact, any sharp edges will favor fibrous material to attach, accumulate and clog the jets.
Advantages that can be derived from the present invention are as follows:

1333i.~.00 It permits a proper internal and external quality control inspection of each jet aerator header module before its assembly to top quality F.R.P. pipes.
It allows the use of standard F.R.P. pipes meeting 5all constructional requirements dictated by 41GP22 and PS15-69. No alteration of these pipes is necessary. Pipes can be fabricated from one of the two methods allowed, e.g.
filament-wound type or manual hand lay-up construction.
It allows the primary jets to be centered very concentrically with the diffuser pipe (venturi) by mean of a molded recess forming a cavity precisely designed to receive the primary jet.
It allows to proceed with piping size reduction for the water and air pipes. Reducer fittings can readily be built up within the molded jet module along with the socket connections provided in on each side of the module.
It allows to provide all necessary attachment pieces readily molded within the jet module assemblies to unable the anchoring of an aeration header from the bottom of a basin/lagoon.
It provides truly concentric alignment for all piping connection with each jet module by means of molded end sockets.
It allows a better quality of construction of the jet header with all components complying with the 41GP22 and PS15-69 construction codes.
More important is that the jet header completely comply to the same standards of construction as a finished product.
30It allows the jet aeration header to be assembled near thejob site and/or on the job site itself if desirable.
In fact, the aerator modules can be shipped on the job site to be assembled locally with standard F.R.P. pipes.
To be able to provide a state of the art jet header construction that complies with the 4lGP22 and PS15-69 standards as a finished product, this invention is based on the prefabrication of each of the jet aerator in the form of complete individual jet module.
The fabrication of most of these components is basically done by contact molding using manual lay-up construction method. All critical transitions can be molded carefully and each of the pieces are finally assembled together to form a complete jet module truly complying with 4lGP22 and PS15-69 construction codes. These jet aerators so formed are then ready to be connected with non-altered, standard approved F.R.P. pipes. When all joints are performed to the same quality standard, the whole jet aerator header also truly complies with 41GP22 and PS15-69 codes as a finished product.
As was already explained hereinabove, the modularity of construction can be offered in tWo!majors versions, namely 1. a split modular jet assembly, that is disclosed herein-after but not claimed; and 2. a monoblock modular jet assembly, that is the invention specifically claimed hereinafter.

In the split modular jet assembly, each jet module is constructed in two identical halves boxes to be sealed and linked together with hardware or other mean. The primary jet, secondary jet and the air transfer pipe are to be attached between these two halves during the assembly.
In the monoblock modular jet assembly, prefabricated jet modules are constructed so as to be ready to be mounted on regular non altered fiberglass pipe. This monoblock version that is claimed hereinafter has the A

1333~00 advantage of avoiding any sealing requirement within the jet assembly as each component piece of the modular assembly is fabricated in one piec- instead of ~
!

/

- 8a -1333~0 construction.
Both constructions are of the modular type and allow for a better quality of construction e.g. permit to meet the established Canadian 41GP2Z and corresponding American PS15-69 fabrication standards.
A description now follows of preferred embodiment of this invention having reference to the appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a perspective and exploded view of a header module made according to the first embodiment of the invention called "split modular jet assembly";
Figure 2 is a perspective and exploded view of a header module section of a jet aeration system incorporating a header module according to Figure l;
Figure 3 is an exploded view in perspective of a header module made according to the second embodiment of the invention called "monoblock modular jet assembly";
Figure 4 is an exploded view in perspective similar to that of Figure 2 but with the module of Figure 3.

Description of the preferred embodiments:

The header module 1, in Figure 1, has an essentially flat body made up of two plate-like parts 3, 5 identical in configuration but where one is a mirror-image of the other, like two symmetrical half shells of a mold.
The parts 3, 5 have large cylindrical through bores 7, 9 normal to the parts outer faces 15, 17 and small cylindrical through bores 11, 13 also normal to the outer faces 15, 17 so that when the faces 15, 17 are flatly applied one against the other, as in Figure 2, and sealed or otherwise secured together, the bores 7, 9 are coaxial and form a wastewater passage 23. Likewise, the bores 11, 13 register to define an air passage 25. Two half cylindrical straight cavities 27, 29 are provided which, in assembly of the plates 3, 5 join together to define a wastewater outlet conduit 31 (Figure 2) extending laterally from the wastewater passage 23 and out of the header body through a port 33.
As said before, the module 1 further comprises air feed means connecting the air passage 25 and the wastewater outlet conduit 31 and so constructed as to draw air or receive air under pressure from the air passage 25 and deliver it into the outlet conduit 31 for mixing with the wastewater flowing from the wastewater passage.
In the embodiment of Figures 1 and 2, the airfeed means comprise a further pair of straight half-cylindrical cavities 35, 37 which, when registering as in Figure 2, define an air conduit 39 joining the air passage 25 and the watewater outlet conduit 31. The air feed means further comprise a venturi cone 41 located within the outlet conduit 31 as shown in dotted lines in Figure 1. The large base of the cone is made solid with the inner wall of the outlet conduit 31 upstream of the air conduit 39. The venturi cone 41 extends fully beneath the outlet opening of the air conduit 35. In this manner and according to the Venturi principle, wastewater under pump pressure in the passage 23 flows through the cone 41 and is subjected to a drop in static pressure at the outlet of the cone which creates a suction effect suitable to draw atmospheric air from the passage 25 via the air conduit 39, which air mixes with the wastewater in the conduit 31. Air can also be fed under pressure.
As mentioned previously and for best performance, the header module 1 is made entirely of fiberglass reinforced polyester (F.R.P.) material.
In use of a jet aeration system for aerating ~, wastewater in an aeration basin or lagoon, a plurality of header modules 1 are disposed across the basin in spaced apart relation and with their passages 23 and 25 coaxial.
As gathered from Figure 2, wastewater pipes 43 have their ends slid and secured into the sockets defined by the passages 23 of successive modules so that the assembly of the modules 1 and pipes 43 define a pressurized wastewater plenum pipe-line feeding into the wastewater outlet passages 31. Air pipes 45 are connected to the air passages 25 of the spaced modules in the same manner.
Secondary jet nozzle (not shown in Figure 2) may be provided in the parts 33 of the outlet conduit 31 to best suit the actual applications.
As illustrated in Figure 1, the ends of the wastewater pipes may be secured in sockets formed in each body part 3, 5 by a counterbore 47 separated from the bore 49 of the passage 9 by a radial shoulder 51 against to which the pipe end may abut. A similar construction may be applied to the air passage 11. On the other hand and as shown in Figure 2, the shoulder feature may be avoided and the ends of adjoining pipes made to abut one another.
In the embodiment of Figures 3 and 4, the body of the header module 53 comprises a first cylinder 55 which defines the wastewater passage 23'; this first cylinder having end sockets 57, 59 for the connection of wastewater pipes 61, 63. A second cylinder 65, also having end sockets 67, 69 for air pipes 71, 73 defines the air passage 25'.
The wastewater outlet conduit here is a third cylinder made up of a nipple 71 solid with and extending laterally of the first cylinder 55; the transverse section of a T-pipe coupling 73 of which one socketed end 74 is connected to the nipple 71, and a nozzle 75 connected to the other socketed end 76 of the T-coupling 73. A fourth arcuate cylinder 77, part of the air feed means, joins a socketed end 78 of the stem section of teh T-coupling 73 and a nipple 80 on the second cylinder 65. Finally, the air feed means venturi cone 81 is provided in the nipple 71 and connected in the same manner as the venturi cone 41 in the module of Figures 5 1 and 2. The cylinders and venturi cone are solid with one another and form an integrated modular unit.
It will be noted that the first and second cylinders 55, 65 are parallel while the third cylinder (nipple 71, branch 74, 76 of T-coupling 73 and nozzle 75) 10 and the fourth cylinder 77 extend normal to the first and second cylinders 55 and 65.
As in the first embodiment also, all components of the header module 53 are molded in F.R.P. material.
The operation of the module 53 is obviously the 15 same as that in Figure 1.

Claims (7)

1. In a jet aeration and mixing header for use in a water or wastewater treatment system, said header comprising:
- a first cylinder defining a water passage, - a second cylinder extending parallel to the first cylinder and defining an air passage;
- at least one water outlet conduit connected to said first cylinder and laterally extending therefrom to allow water to be expelled out of said water passage;
- at least one air-feed cylinder, each air-feed cylinder connecting the second cylinder to one of said at least one outlet conduit at a given point of connection along said one outlet conduit to allow air to be delivered from said air passage into said water flowing through said one outlet conduit; and - a venturi cone mounted in each outlet conduit, said cone having a wide inlet extending across the outlet conduit upstream said point of connection of the air-feed cylinder, and a narrow outlet extending centrally in said outlet conduit downstream said point of connection to allow, in use, air to be drawn from the air passage and mixed with the water expelled through the narrow outlet of said cone;
the improvement wherein:
- each water outlet conduit is made up of a nipple solid with and projecting from said first cylinder and of a T-shaped coupling having a stem section and a transverse bar section, said transverse bar section being connected at one end to said nipple to form therewith said outlet conduit with said stem section acting as said point of connection for the air-feed cylinder connected to said outlet conduit.

2. The improved header of claim 1, further comprising a nozzle connected to each transverse bar section forming part of one of said at least one outlet conduit, opposite to the one end of said transverse bar section connected to said nipple, said nozzle having an inlet having an internal diameter substantially identical to the diameter of said transverse bar, and an outlet of smaller diameter.

3. The improved header of claim 2, further comprising sockets integral to some of its structural elements to interconnect all of said elements by mere fitting.

4. The improved header of claim 1, 2 or 3, wherein the wide inlet of each venturi cone has an internal diameter substantially identical to the diameter of the outlet of the nipple adjacent thereto.

5. The improved header of claim 5, wherein each venturi cone extends into the transverse bar section of the T-shaped coupling forming part of said outlet conduit so that the wide inlet of said venturi cone is close to the outlet of the nipple to which said outlet conduit is connected.

6. The improved header of claim 1, 2, 3 or 5, wherein said first pipe has a plurality of nipples solid thereto and a plurality of water outlet conduits and air-feed pipes connected to said nipples.

7. The improved header of claim 1, 2, 3 or 5, wherein said first pipe, said nipples solid to said first pipe and said second pipe are all made of fiber reinforced plastic material.