Note: Descriptions are shown in the official language in which they were submitted.
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IMPROVED CATCH BASIN
This invention relates generally to separator tanks or catch basins, so.,.rl;.n~s
called interceptors, adapted to receive primarily Minwater from a storm sewer ordrain, and additionally to perform the function of sepaldl~lg and ~llLldppillg any oil- or
gasoline-based materials and suspended solids that may enter, allowing the waterfraction to discharge into municipal receiving sewers.
PRIOR ART
Prior art devices of the kind described above are typically equipped with
various baffles and chambers operating in such away as to collect specific components
of the waste fluid and separate them from others. One representative prior patent is
~ U.S. 4,136,010, issued January 23, 1979 to Pilie et al.
An improved construction for a separator tank is the focus of U.S. patent No.
4,985,148, issued January 15, 1991 to Joseph G. Monteith. The purpose of the tank
interceptor set forth in the latter patent is to provide two distinct responses to two
dirre~ opel~Lillg conditions:
(1) When the materials entering the interceptor include discharge from a
service station, garage, m~ in~ shop, factory or the like, or oil that has
spilled accidentally, these non-aqueous materials are collected within the
interceptor. The aqueous fraction is allowed to leave the interceptor and
pass on to a storm sewer or the like, but the liquid fraction--made up of oil
or fat of animal, vegetable or mineral origin, gasoline and the like-remains
2 5 trapped within the illL~l~;epLor until the same is pumped out. Further, any
heavier-than-water materials sink to the bottom of the interceptor and are
confined to a particular location from where they can also be pumped out
at intervals.
(2) The interceptor of the prior invention is also adapted to deal with inflow
3 o res~ ing from heavy rain during a storm. Such inflow would typically be
a combination of storm drainage from an adjacent industrial plopelly,
garage or the like, as well as inflow from storm drains adapted to catch
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rainwater. When a large quantity of l~illw~tel arrives at the interceptor of
the prior invention, the interceptor ~ULo~ r~lly diverts most of this flow
directly to an outlet opening which passes it directly to a storm sewer.
Only a portion of the flow of the incoming l~illw~l~l is allowed through
the tre~tm~nt/storage chamber of the interceptor.
To accomplish the aforesaid goals, the prior art separator disclosed in U.S.
patent 4,985,148 provides, within the tank-like interceptor, a passageway extending
substantially directly between the inlet and the outlet. The passageway is essentially
0 sealed from collllllunication with the rem~in-l~r of the interior of the tank interceptor,
except for an opening adjacent the inlet and an opening adjacent the outlet. Each
opening co"""lll-ir~tes the passageway with the rem~in-ler of the tank interior, which
may be regarded as a treatment chamber. Finally, a weir means is provided within the
passageway, disposed with respect to the first opening such that, under relatively low
entry flow rates, all entering materials are contained by the weir and flow through the
first opening and into the treatment challlbel, whereas under relatively high entry flow
rates, part of the entering materials overflow the weir and are delivered by thepassageway to the outlet.
Recognizing that it was llnn~cess~ry for the entire volume inside the
2 o interceptor tank (except for the passageway means) to be used as a ll~al~ llL chamber,
and in view of the desirability that the structure providing the high-flow passageway
be more fully accessible to personnel wishing to inspect the installation for damage, or
the illl~r~el ~rcllnnll~tion of materials, I developed a design in which a separator
tank provided a treatment collll)al~lllent in the bottom portion thereof and a convenient
area above the treatment colll~alLul~lll where inspection personnel could stand. The
separation is accomplished by a partition integrally defining a weir encouraging all
fractions of a low liquid inflow to pass dowllw~ldly into the treatment colll~?alllllent
but which, under high flow rates, permits enlelillg liquid to pass directly across and
above the partition to an outlet, effectively ov~llulll~illg the built-in weir. The latter
development is now the focus of U.S. patent No. 5,498,331, issued March 12, 1996,
entitled "Tank Interceptor".
I have now developed a compact, inexpensive and effective design for a catch
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basin intended to separate inflowing liquid into an aqueous fraction, a floatable
fraction above the aqueous fraction, and pleci~iL~ g sediments, solids, etc., but
which under high flow rates of entering liquid (as may occur during a rainstorm)permits ellL~lillg liquid to pass directly to the outlet with only a very small fraction
entering the lower treatment chamber.
Due to the design, any portion of the high-velocity entering liquid which does
enter the lower treatment collll)al~lllenl will do so at a controlled rate of speed which
allows the separated fractions to remain separated.
GENERAL DESCRIPTION OF THIS INVENTION
More particularly, this invention provides an improved catch basin, comprising:
-- a hollow container having a bottom wall, a side wall and a top wall which together
define an internal volume,
-- an inlet in said top wall,
-- an outlet in said side wall,
-- partition means dividing the internal volume into a lower col~ al Llllent and an upper
COlll~alLlllent, the partition means including:
an intake region disposed so as to directly receive at least a portion of the
liquid entering through said inlet,
an outlet region disposed adjacent said outlet in the side wall, and positioned
so as to substantially prevent it from directly receiving any liquid entering
through said inlet,
an intake opening in said intake region,
an outlet opening in said outlet region,
2 5 directing means adjacent said intake region so disposed that the intake region
and the directing means, between them, receive substantially all of the liquid
entering through said inlet, the directing means being configured to direct
liquid il~ hlg thereon toward said intake opening, but so as to allow liquid
entering in large quantity to pass directly to the outlet region;
3 o -- an intake conduit conn~cted to said intake opening, and extending dowll~rd into
the lower colll~alllllent to an interm~ te location therein, where it co~ ir~t~swith the lower culll~lLlllellL,
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-- an outlet conduit conn~cte~l to said outlet opening, and extending dowllw~rd into the
lower culll~alllnent to an inte~ te location therein, where it co""".l,~ic~tes with
the lower collll~al Illlell~,
-- whcleby, under conditions of low liquid flow into the catch basin, substantially all
entering liquid will be directed to said intake region, will descend along the intake
conduit into the lower collll.alllllent, and will separate into floatables on top, an
aqueous phase under the floatables, and solids collecting on the bottom wall;
-- and whereby, under conditions of high liquid flow into the catch basin, a portion of
the liquid will overrun the directing means, gain direct access to the outlet region, and
exit from the catch basin through the outlet.
BRIEF DESCRIPTION OF THE DRAWINGS
Two embodiments of this invention are illustrated in the accolll~allyhlg
drawings, in which like numbers denote like parts throughout the several views, and
in which:
Figure 1 is a vertical, axial sectional view taken axially through a first
embodiment of a catch basin according to the present invention;
Figure 2 is a horizontal cross-sectional view taken at the line 2-2 in Figure l;and
2 o Figures 3 and 4 illustrate a second embodiment of a catch basin according to
the present invention, and correspond to Figures 1 and 2.
DETAILED DESCRIPTION OF THE DRAWINGS
Attention is first directed to Figure 1, which shows a first embodiment of a
catch basin generally at the numeral 10, the catch basin 10 having the shape of a
hollow container 12 with a substantially circular bottom wall 14, a cylindrical side
wall 16, and a circular top wall 18.
There is an inlet 20 in the top wall 18, and an outlet 22 in the side wall 16.
The inlet 20 is an open grate 23, typically of cast iron. It will be noted that the
3 0 inlet 20 is eccentrically located with respect to the circular top wall 18, and that its
direction of displacement is opposite that of the outlet 22.
A partition shown generally at the numeral 24 has a substantially circular outer
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perimeter 26 which is sized to fit snugly within the cylindrical side wall 16.
The partition 24 has its mid-region shaped to define an obliquely inclined
sloping ramp 28 extending leftwardly and dowllw~rdly from a substantially horizontal
upper edge 30 to a horizontal lower edge 32. A substantially vertical wall 34,
5 rectangular in configuration, extends dowllwal-lly from the upper edge 30 to a lower
edge 36 defining a rectilin~r internal limit of an outlet region 38 having the shape of a
circular segment. There is an outlet opening 40 located substantially centrally of the
outlet region 38, the outlet opening con~tihlting the upper end of an outlet conduit 42
which extends substantially vertically dowllw~Ld adjacent the cylindrical side wall 16,
1 o the outlet conduit 42 l~, ."i~ i ng at an open bottom end 44.
The partition 24 further defines an intake region 46 which is disposed
diametrically opposite the outlet platform 38, and which likewise has the form of a
circular segment including a rectilin~r inner edge defined by the lower, leftward limit
of the ramp 28. Provided in the intake region 46 is an intake opening 48
5 co~ ni~ting with the top of an intake conduit 50 which has a bottom end in
collllll.lnir~tion with a T-fitting 52 shaped so as to direct liquid which descends along
the int~ke conduit 50 in tangential directions around the inside of the circular side wall
16, thus promoting laminar flow rather than turbulence.
By suppressing turbulence, the floatable fraction of the incoming material can
2 o separate from the aqueous fraction and float upwardly to collect under the partition 24,
trapped in that location by the vertical extent of the conduits 42 and 50. At the same
time, solids will tend to precipitate and collect against the bottom wall 14.
In the embodiment illustrated, the catch basin provides a clean-out access
means in the form of an upst~n-ling pipe 54 with a closure 56 for the top the part 54,
25 the closure 56 allowing air to escape from the lower COllll)alLIllell~ as the latter fills
with liquid, but substantially preventing the entry, into the lower colll~alllllent, of
liquid that directly arrives from the inlet 20 in the top wall 18.
It will also be noted that the inlet region 46 and the adjacent part of the ramp28 support two vertical guide plates 58 which extend leftwardly from the pipe 54 and
3 o enclose the intake ope~ g 48 on two sides thereof. The purpose of the two vertical
guide plates 58 is to create a vortex which draws floatables into the intake opening 48.
It will be noted that the outlet region 38 has a slightly lower vertical position
CA 02206338 1997-0~-28
than does said intake region 46. This dirrelel1ce in height (of approximately one inch)
will tend to promote outflow through the outlet conduit 42 and the outlet 22.
It will thus be appreciated that, under conditions of low liquid flow into the
catch basin 10 (the liquid descending directly from the grate 23 in the top wall 18),
substantially all of the entering liquid will be directed to the intake region 46, will
descend along the intake conduit 50 into the lower cu~ alllllent, and will tend to
separate into floatables on top, an aqueous phase under the floatables, and solids
collecting on the bottom wall 14. Entering liquid which impinges directly on theclosure 56 will run off the closure 56 and down along the outside of the pipe 54,
0 eventually finding its way to the intake opening 48. The rem~ining water entering
through the grate 23 will end up going through the intake opening 48, due to theaction of the ramp 28 and the guide plates 58.
However, under conditions of a high liquid flow into the catch basin 10, a
portion of the entering liquid will build up (due to the restriction represented by the
opening 48) and eventually overrun the ramp 28, thereby gaining direct access to the
outlet region 38 from which it can leave the catch basin through the outlet 22.
Attention is now directed to Figures 3 and 4, showing the second embodiment
of this invention. The plilllaly dirr~lellce between the first and second embodiments
illustrated in the Figures relates to the configuration of the ramp, identified by the
2 o number 28 in Figure 1, and by the number 28a in Figure 3. It will be noted that the
ramp 28a in Figure 3 defines a smaller angle with respect to the horizontal than does
the ramp 28 in Figure 1. This places the leftward edge 32a of the ramp 28a at a
higher vertical position than the edge 32. Leftwardly from the edge 32a, the partition
24a incoll~ol~t~s a dowllw~ldly converging throat portion 61 which colll~ icates2 5 with the top of the intake conduit 50a. The dowllw~ldly collv~lgillg throat portion 61
promotes the creation of a vortex which allows floatables such as oil to enter the lower
tre~tmPnt chamber through the intake conduit 50a.
The rem~ining components of the second embodiment of this invention
correspond in configuration and function to the equivalent components discussed
3 o above with reference to Figures 1 and 2.
While two embo~lim~nt~ of this invention have been illustrated in the
accolll~allying drawings and described hereinabove, it will be evident to those skilled
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in the art that changes and modifications may be made therein, without departing from
the invention as set forth in the appended claims.
