Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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MODULAR AERATOR AND SEPARATOR ASSEMBLY
FOR SEWAGE TREATMENT FACILITY ~''
This invention relates to modular drop-in type aeration . -
and separation units for use in relatively small sewage treatment '~
plants of the type commonly found proximal to mobile home parks
or the like. More particularly, it is concerned with such modular ~'
assemblies employing aeration diffusers situated adjacent the
sewage inlets thereof in order to produce an upwardly directed, ""
hydraulic suction for more efficiently treating sludge and other `~
solid materials entering and collected within the assembly.
Unique means are also provided for trapping grease and the like
prior to particulate separation, with the grease collector also '''~'
serving as an air diffuser to facilitate intermittent cleaning of ';
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the interior of thé assembly.
In the past, it has been a common practice for mu- ''
nicipalities or others to simply dump raw sewage into adjacent ';
streams and waterways, rather than pretreating the sewage to `~ `
remove'organic and other pollutants therein. This practice was
of course'objectionable'to those living downstream from the '~
dumping site, and moreover presented serious health and ecological ~'
hazard. In extreme'cases, the'water could be rend~red unfit for
use without extensive purification thereof, thus necessitating
the'employment of relatively sophisticated water treatment facili~
ties.
In recent years however, increasingly stringent govern- '~
mental regulations have prohibited or drastically reduced the '`
possibilities of lawfully disposing of raw sewage in a variety '~
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of ways to remove essentially aLl of the pollutants prior to
return thereof to the waterways.
The problems alluded to above are especially significant
in the case of developing housing communities or mobile home ''~
parks. These are generally built at unimproved sites not having ;
sewage systems, near the outskirts of existing towns or cities. ';'
This difficulty has led to the refusal of building permits for ~'-'
such new housing communites solely on the basis of the cost of " ''
either expanding the existing metropolitan sewage system or of ~ ''
building a separate sewage treatment plant. Thus, otherwise
desirable housing plans have been stalled because'of the lack of ~"
adequate sewage treatment. '
In response to the'foregoing, it has been suggested to `'''
construct and install relatively small sewage'treatment plants ''''
adjacent new housing communities or mobile home paxks. As can be i~'
appreciated, such plants are generally much'smaller than those ~'
constructed to serve'a large city, and in order to be feasible ~ '~
the construction and operation costs thereof must be'held to a
minimum. In this connection, there has been a notable lack of "~
modular drop-in type'aeration and separation assemblies for
use in such small treatment facilities, and accordingly such
units have generally been constructed on-site, which is of course `''';
a costly and time-consuming proposition. Ideally, such a modular
unit should be relatively light in weight, low in cost, and of a ~' '
size to permit easy transportation and installation thereof in '`
the field. In addition, the operational characteristics of such ~'
an assembly should be such that only a minimum amount of continuing -~
service is required. ~'
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It is therefore the most important object of the present ''~'~
invention to provide a substantially self-cleaning, drop-in ''
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modular aeration and separation assembly especially adapted for
use in relatively small sewage treatment plants and which is of a
size and weight to facilitate'easy transportation and instal-
lation thereof in the field and requires little or no continuing :~.
maintainence for the operation thereof.
Another object of the in~ention is to provide a modular
drop-in type aeration and separation assembly employing aeration :
diffusers or conduits situated adjacent the'lower sewage inlet ~ ''
openings thereof for inducing an upwardly directed hydraulic
suction or "pumping action" on the sludge'and particulate '
material entering and within the assembly so that the turbulence . .:
and conseq~ent aeration thereof is maximized; and diffusers are
preferably positioned behind generally upright baffles so that ~.
solids carried by the liquid sewage do not clog the dif~user air ~ .
outlets. '.
Another obj'ect of the invention is to pr~vide a modular :;
assembly of the type described including a multi.-channel par~
ticulate removal section situated within the assembly and operable
to remove particulate matter from the .sewage'passi.~g upwardly .. ':
therethrough; in~this connection, it is especially pre~erred .'~
to provide a separation unit including a plurality of elongated,
obliquely disposed, side-by-side sewage-conveying tubes with the ~' '
longitudinal axes of the tubes being disposed in opposite dir-
ections~in alternating rows: thereof, so that the impingement of
entrained solids against the defining sidewalls of the separation
unit is maximized. ..
Another object of the invention is to provide uni~ue
grease collector means situated beneath the particulate removal .
section in order to remove'grease and the like prior to entrance ':'
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thereo~ into the removal section so that the latter does not ... :
become clogged; in preferred forms, the grease collector is
of inverted V-shaped configuration, and combination
aeration and grease suction pipe assemblies are provided :
therewith for continuously withdrawing collected grease .~
therefrom, and for selectively delivering volumes of compressed ~ ; ..
air into the confines of the collector so that the air is .
diffused by virtue of the configuration of the collector ~: :
and is allowed to pass upwardly through the partlculate ;.. :.:
removal section thereabove in order to clean the same. ;;~
In general terms, the present invention provides, .
in one.aspect thereof, a sewage treatment apparatus,
comprising: a bottom wall adapted to hold sludge and particu~
late matter derived from said sewage; particulate separation ~ ~.
means situated above said bottom wall and operable to remove ;.
particulate matter from sewage passing therethxough and ~
permit gravitation of said matter towards the bottom wall; ~ . .
generally upright chamber-defining means presenting a chamber ~ .:
for directing the flow of sewage through said separation means
after entrance thereof into the apparatus, there being a :.
sewage inlet located adjacent the bottom of said apparatus .
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whereby sewage enters the latter and flows upwardly through
said chamber and separation means; aeration means locatecl .
adjacent said sewage inlet and operable to induce a generally
upwardly directed hydraulic suction for increasing the tur- . .
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bulence and aeration of said sludge and particulate matter;
and means located above said particulate removal means for .. :.
permitting withdrawal of clarif.ied liquid emerging therefrom. ;~
~ In another aspect, the invention provides .:
sewage treatment apparatus, comprising: a bottom wall adapted ..
to hold sludge and particulate matter derived from said sewage; ~:
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particulate separation means situated above said bottom
wall and operable to remove particulate matter from sewage
passing therethrough and permit gravitation of said matter
towards said bottom wall; generally upright chamber-defining ~-
means presenting a chamber for directing the flow of sewage
through said separation means after entrance thereof into
the apparatus, there being a sewage inlet located adjacent
the bottom of said apparatus whereby sewage enters the
latter and flows upwardly through said chamber and separation
means; means located above said particulate removal means
for permitting withdrawal of clarified liquid emerging there-
from; air diffusion structure situated below said particulate ;~
separation means and above said sewage inlet; and means for
selectively directing volumes of air for release within the
confines of said air diffusion structure, whereby the air is
diffused during upward travel thereof to clean said particulate
separation means thereabove. ~;
Preferably, said air diffusion structure is also
~; operable to collect grease or the like floating on said
sewage, said diffusion structure comprising an elongated, $~
closed top, downwardly opening channel-like member, there
being means for withdrawing the grease and the like from
within the confines of said member. `
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In the drawings:
Figure 1 is a perspective view of the drop-in
modular aeration and separate assembly of the present
invention, shown operatively installed in the receiving
basin of the sewage treatment facility; i -
Fig. 2 is a f~agmentary plan view of a typical
sewage treatment facility employing the aeration and
separation assembly hereof;
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Fig. 3 is a vertical sectional view of the aeration ~
and separation assembly illustrated in Fig. 1, and showing `~ ;
the internal construction thereof; and
Fig. 4 is a vertical sectional view taken along
lines 4-4 of Fig. 3 and further illustrating the internal
construction of the overall assembly.
- Sewage treatment apparatus 10 in accordance with `
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the invention is shown in Fig. 1 and broadly includes a
bottom wall 12b adapted to hold sludge and particulate matter ~;
derived from sewage to be treated. A particulate removal
section 14 is situated above bottom wall 12 and is enclosed "
by defining walls which present a generally upright, open-top
chamber 16 for directing '
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liquid sewage upwardly through apparatus 10. The'latter also '
includes a pair of elongated, opposed sewage inlet openings 18 ' '
situated adjacent the lowermost end thereof, with separate aera- ' '
tion means in the form of elongated, perforated air conduits or :.
diffusers 20 positioned within the respective sewag~ inlet open-
ings. Finally, the unit also includes a closed top, open bottom
grease collector 22 of inverted, substantially V-shaped con~
figuration for trapping grease and the like floating on top of
the liquid sewage passing through apparatus 10. A pair of opposed
pipe sections 24 extend beneath collector 22 on the respective "~
ends thereof for purposes which will be made clear hereinafter. ~.
Although forming no part of the present invention, it':
is to be understood that apparatus 10 is adapted to be utilized
to good advantage in a conventional waste'treatment facility such .
as that shown fragmentarily in plan in Figure'2.. In particular, "'
the facility includes an elongated receiving basin 26 adapted to '':
receive raw sewage from an inlet conduit 28. Sewage passes ~'
through the inlet openings 18 of apparatus 10 and is transferred
after treatment thereof to a large finishing basin 30 in order to
complete the aeration and purification thereof... The pruified '~
water can then be returned to an adjacent river or stream in the `'.
well-known manner. The facility also includes a control house 32
for housing laboratory and chlorination equipment~ as is con- ~'
ventional in these types of installations. ;~
In more'detail, bottom wall 12 of apparatus 10 includes .
a generally planar, horizontal section along with a pair of `~
generally upright marginal baffle sections 33 exten~.ling upwardly
therefrom. Chamber 16 thereabove is defined in part by a pair of
spaced, opposed sidewalls 34 each having an angularly inwardly''
extending lowermost extension 36 which extends beneath the
level of the adjacent upright baffle 33'and is spaced inwardly~.
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therefrom. In addition, chamber 16 is also defined by opposed, ~ ;
generally planar end walls 38. Thus, the opposed sewage inlet
openings 18 of apparatus 10 are cooperatively defined by the
respective upright baffles 33 and adjacent extensions 36 and the ~
lowermost portions of end walls 38. ~'
Particulate removal section 14 preferably comprises a
multi-tube unit presenting a plurality of obliquely disposed, ;
open-ended settling tubes 40. The'tubes are advantageously
arranged in rows' with the longitudinal axes of the tu~es being in
opposite directions in alternating rows. The separation section
14 is of a size to extend between the side and end walls of
chamber 16 so that sewage passing upwardly through apparatus 10 - '
must pass through'the separation unit for treatment therein. As '' '''
best shown in Fig. 4, the multi-tube separation section 14 is
supported within chamber 16 by means of a series of spaced, ','
transversely extending support channels 42. It will also be seen '
that the'defining walls of chamber 16 extend above the parti-
culate`removal section 14 and define a hollow, open-top space 44
for the reception of clarified water emerging from se~tion 14
prior to transfer thereof to finishing basin 30 of the treatment ~ `~
facility.
An elongated support rail 46 is attached to the'
uppermost end of each'chamber-defining sidewall 3~ and extends '~''
beyond the respective end walls 38 thereof for the purpose Of !.
supporting apparatus 10 within receiving basin 26 of the sewage '
treatment facility. In addition, a cross brace member 48 is '
attached to the uppermost end of each end wall 38 for the purpose
of rigidifying the overall apparatus. Rails 46 support upright ~''
railings 50 as well as a plurality of hingedly mounted grating ~"
sections 52 which present a continuous walkway over apparatus 10. `~
Sections 52 can be'selectiveLy opened as shown to allow '
access to apparatus 10. `; '
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As explained, grease collector 22 is of inverted, ~' '
substantially V-shaped configuration with the diverging sidewalls ~
thereof opening downwardly towards bottom wall 12. In this '
connection, the lowermost marginal edges of the sidewalls are
provided with a plurality of spaced air diffusion slots 54 along
the length thereof which are'important for purposes to be made
clear hereinafter. Moreover, pipe sections 24 extend a short '
distance beneath the confines of collector 22 and are of a size
to permit continuous suction withdrawal of grease or the like ''`'
trapped within collector 22, or to selectively permit volumes of ~'
air to be deIivered beneath the collector for cleaning of appa-
ratus 10.
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Separate, eIongated, upright pipe'assemblies 56 are '~'
connected to each section 24 and extend upwardly therefrom ex- ~;
ternally of apparatus 10 to a level above the'top of particulate
removal section 14 and terminate in an openended eIbow 57.' Each ~'
of the assemblies 56 includes a gate'valve'58 therein which can
ke selectively operated by means of handles 60 (~see Fig. 1) in
order to control the operation thereof. In addition, separate
skimmer conduits 50 extend through the'respective'e.nd walls 38 of
apparatus 10 and~are interconnected outside the latter to the
corresponding pipe'assemblies 56 above the'level of ~he valves 58
therein. Each'conduit 59 includes an open-top skimmer attachment
61 at the end thereof within space'44. Separate'compressed air
conduits 66 are also interconnected between the respective assem- `
blies 56 below the`level of valves 58 therein and one of the com~
pressed air conduits 62 situated within the confines of the
support rails 46. A manually operable valve'68 is interposed
within each conduit 66 to control air flow theret'hrough.
Each elongated compressed air conduit 62 also includes "
a number of spaced, depending, communicating conduits 64 which '"
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are connected at the lowermost ends thereof to the generally
horizontal, perforated aeration pipes or diffusers 20 situated ''
within the inlet openings 18 of apparatus 10. The diffusers 20
are preferably positioned below the'uppermost marginal edges of ~-~
the adjacent baffles 32 so that rags or other solid wastes carried
by the liquid sewage do not clog the diffusers. The respective -
conduits 62 are connected by means (not shown) to an air pump for ''
deIivering volumes of compressed air to the m~lti-orifice diffusers
20. Finally, a relatively large, elongated collection pipe 70 is ''' ~'positioned within space'44 above particulate'removal section 14.
Pipe 70 has a number of orifices 72 along the'length thereof for ~'
the collection of clarified water emerging ~rom-the particulate
removal section 14. In this respect,- an imperforate'conduit 73
is in operative'communication with pipe 70 for withdrawing the'
clarified water under the influence of gravity and delivering the
same to finishing basin 30 of the treatment facility. ~'
In operation, sewage'to be'treated is directed to '-
finishing basin 26 whereupon the'sewage'enters apparatus 10 '
through'the'opposed, lower inlets 18 thereof. At the same'time, ' ''~'
volumee o~ compressed air delivered through conduits 62, 64, and ~
dif~users 20 create an upwàrdly directed stream of air bubbles' ~'
which ensures that particulate'matter and other solids entering
apparatus 10 are freshly aerated. In addition, an~ sludge'or
particulate matter collected within ~he'con~ines of bottom wall
12 is subjected to a hydraulic suction or "pumping action" which ~;
serves to agitate'such matter to further aerate c~nd more com~
pletely purify the'sewage. This bubble flow and the consequent''
suction and aeration action of the compressed air is depicted by '`~
way of bubbles 74 leaving the'separate'diffusers 20 and traveling
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to the top of the'liquid sewage. In addition, valves 68 and 58
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within conduits 66 and assemblies 56 respectively are open during
normal operation of apparatus 10 in order to create'a suction ~ '
action within pipes 24 and skimmer conduits 59, which is important
for purposes to be'made clear hereinafter. Such suction action '
arises by virtue of the flow of compressed air through conduits
66, the upper por~ions of assemblies 56, and ultimately out the
external open-ended elbows 57. ~ ",
The rising sewage next encounters grease collector 22
which is operable to skim grease and other materials floating on
top of the liquid sewage prior to upward passage'of the latter
through particulate removal section 14. Specifically, grease
floating on the'sewage rising through'apparatus 10 collects ~ '
against the undersides of the diverging sidewalls of the V-shaped
collector 22 and is trapped within the conines thereof. In this
connection, the induced suction action within pipe sections 24
serves to continuously withdraw the collected grease'from collec-
tor 22 for ejection thereb through'elbows' 57 externally of
apparatus 10. In this fashion, essentially all of the objectionable
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grease or the~like is removed from the sewage so that such material ~"
cannot clog the sewage'conveying tubes of section 14.
The sewage next traveIs upwardly through'chamber 16 ,`~
for travel through the multi-tube particulate'removal section 14.
In this respect, the'alternating, oblique'orientation of the
sewage-conveying settling tubes of section 14 ensures that any ,
particulate matter entrained within the sewage-impinges against ,
the defining sidewalls of the section so that such particulate `
matter is separated rom the liquid and is allowed to gravitate
towards bottom wall 12 for collection and urther agitation and ,
aeration as described. A further explanation of the construction
and operation of the preferred multi-tube particulate removal
section 14 hereof is contained in U.S. Patents Nos. 3,491,892 and
3,615,025.
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After emerging from section 14, the substantially '.'
clarified and skimmed water within space'44 can be'transferred by
means of pipe 40 to finishing basin 30 for final purification.
In this regard the fact that pipe'70 is submerged beneath the
level of water within space 44 eliminates problems of ice for- :.
mation and weir cleaning common to previous units of this type. ~'.
Moreover, any remaining grease floating on top of the water in
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space 44 is skimmed off and delivered e~ternally of apparatus 10 :~
by means of the internal open-top skimmer attachments 61 and the
negative pressure within conduits 59 attached thereto.
The present in~ention is also extremely advantageous by '~ ~:
virtue of the self-cleaning features thereof. For example, . .
collector 22 serves as an efficient air diffuser for facilitating . :
the cleaning of apparatus 10 and especially section 14 thereo~ as
desired. When it is desired to clean the sewage-conveying tubes '
of section 14, it is~only necessary to manipulate handles 60 ~ :
associated with gate valves 58 to temporarily close'the latter
and interrupt suction removal of grease from collector 22, whereupon ~ .
compressed air from the conduits 66 flows downwardly in the `~
separate upright pipe sections-56 for delivery beneath'the col~
lector 22. This action is depicted in Fig. 4 and illustrates ;
that when volumes of air are thus directed within the'confines of ~` .
collector 22, the air is spread out and diffused by the'con- '.;'.~'
figuration of the collector so that the rising bubbles of air can ' ~
efficiently and effectively clean the multi-tube'particulate' ~ ~ '
removal section. In this respect, it will be seen that the
spaced diffusion slots 54.along the marginal edges of the diverg-
ing sidewalls of collector 22 serve to even more'evenly spread .. '
out and diffuse the~air for cleaning of apparatus 10. In practice, '
it has been found that during normal usage of apparatus 10 it is .''~
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only necessary to clean section 14 on a bi weekly basis, and that
the combination air delivery and grease removal assembly associat~
ed with collector 22 is especially advantageous for this cleaning.
It will thus be seen that the present invention provides
a modular aeration and separation assembly which is characterized
by its simple construction and efficient, essentially trouble- !
free operation. Moreover, means are also provided for easily and
quickly cleaning the assembly withbut the necessity of shutting
~own tbe treatment fae li~y for extended period~.
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