Note: Descriptions are shown in the official language in which they were submitted.
212 2 9 5 0 G. 8jorkander -2-4
A METHOD FOR UNCLOGGING PUMPS
rN A PUMPING SYSTEMi, AND
V~LVING ARRANGEMENT THEREFOR
~ackground of the Invention
~his invention pertains to pumping systems having a plurality of pump~, which
pumps are susceptible to getting clogged, and in particular to a method for
unclogging such pumps, and also to a valving arrangement useful in the method.
The invention, by way of example, has especial application in municipal sewage
systems which employ pumping systems for evacuating waste wa~er from system
tanks or reservoirs~ Such sewage systems commonly have sewage or waste water
inlets which conduct the ~ewage and/or waste water to the tanks or reservoirs,
and the latter have submersible pumps therein which, when the level of sewage
or waste water becomes considerable, the pumps operate to evacuate the tank or
reservoir contents or simply to lower the level thereof.
Sewage and waste water always contain pollutants such as sludge, and elongated
objects, i.e., ragQ and the like, which all too easily clog the pumps and piping.
In order to diminish this problem, prior art arrangements design the hydraulic
parts of the pumps with very large inl2ts and outlets and having cutting means
for subdividing the troublesome, elongated objects into manageable pieces. An
example of this is shown in Swedish Patent No. 820 5774-6.
In order to diminish the likelihood of sludge banks building up in the sewage
system pumping stations, it is a known practice to employ special mixers or
valves which, during certain periods of time, effect an agitation of the waste
water. The Swedish Patent No. 8900597-9 discloses an example of this arrangement.
There is yet another method which is used to remove the troublesome, elongated
objects from pump inlets. This is to operate the pump or pumps in reverse, for
a short period of time, before commencing the customary, forward-pumping operation.
In thi~ way, rag~ and the like, which are at the pump inlet will be flushed away.
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The instant invention discloses a novel method for unclogging pumps in a
pumping system, as well as a valving arrang~ment therefor, of simple, e~ficient,and inexpe~sive character.
Summary of the Invention
It is an object of this invention, particularly, to set forth, or a pumping
system having (a) a plurality of pumps, and (b) an outlet conduit coupled to
each pump of said plurality, a valving arrangement operative for unclogging
pumps of said plurality, comprising shunt piping for connecting said conduits -
together for co~mon ~luid flow therebetween; and valving means, interposed
in Raid piping, operative in a first mode for prohibiting fluid flow between
said conduits, and operative in a second mode for accommodating fluid flow
between said conduits.
Too, it is an object of this invention to disclose a method for unclogging
pumps in a pumping system, the system having a plurality of pumps, and
each pump having an outlet conduit, comprising the steps of connecting the
outlet conduits together, for common ~luid flow therebetween, with shunt
piping; interposing Ln said piping a valving means which is operative in a
first mode for prohibiting fluid flow between said conduits, and operative in
a second mode for accommodating fluid flow between said conduits; operating
said valving means in said second mode; and operating one of the pumps of the
plurality.
Further objects of this invention, as well as the novel features and pro-
cedural steps thereof, will become apparent by reference to the following
description, taken in conjunction with the accompanying figures.
Brief Description of the Drawings
Figure 1 is a schematic diagram of the novel valving arrangement,
according to an embodiment thereof; and
Figure 2 is a flow or block diagram of the steps in the inventive
method, again according to an embodiment thereof.
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~etailed Description of the Preferred Embodiment
With reference to Figure 1, the valving arrangement 10, in an embodiment
thereof, comprises a shunt piping 12 which, at opposite ends thereof, is in
through connection with outlet conduits 14 and 16, the latter proceeding from
the outlets of pumps 18 a~d 20, respectively. Interposed in piping 12, in
confronting relationship, are two valves 22 and 24. Valve 22 acco~modates
fluid flow therethrough to the right (as viewed in Figure 1), i.e., from
conduit 14 to valve 24. However, it normally prohibit~ flow therethrough
to the left, but can be operated or manipulated (by means not shown) to
permit flow therethrough from valve 24 to conduit 14. Similarly, valve 24
accommodates fluid flow therethroughto the left, i.e., from conduit 16 to
valve 22. It normally prohibits flow therethrough to the right, but also can
~e operated or manipulated to permit flow therethrough from valve 22 to
conduit 16.
The pumps 18 and 20 draw fluid, for instance waste water, by way o~ example,
from tanks 26 and 28, resp~?ctively, via inlets 30 and 3?.. Remote ends of the
conduits 14 and 16 have check ~alves 34 and 36 interposed therein to prevent
a reverse flow of fluid therethrough. Ends of the conduits 14 and 16 commun-
icate, commonly, with a discharge line 38. -
The tanks 26 and 28 are shown as independent. However, they could just as
welL comprise a single tank, as indicated by the dash-dot line extending
therebetween. Tanks 14 and 16, for instance, could simply be a single tank
in a waste water pumping station. Too, the tanks could represent independent,
parallel systems and, instead of conduits 14 and 16 joining the discharge line
38, they could independently discharge their separate effluents. In either
arrangement, the invention serves just as well. ~
For illustrative purposes, it is assumed that the invention is employed in ~;
a waste water or sewage pumping station. Upon the liquid level of the
effluent, i.e., waste water, sewage, and such, reaching to some height in a
tank 26 or 2B, or a common tank, one of the pumps 18 or 20 is turned on to
discharge some or all of the tank-confined effluent. If tank 26 is the one
involved, and pump 18 is turned on, then valve 24 is also operated (by means
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not shown) to accommodate fluid flow therethrough from ualve 22 to conduit 16.
Consequently, a portion of the effluent which is pumped through conduit 14 is
tapped off by the shunt piping 12, conducted through the valves 22 and 24, and
down through conduit 16. This shunted effluent enters the pump 20 and courses
therethrough in a reverse mode to dislodge from the inlet 30 any troublesome,
elongated, pump clogging substances.
After a period of time, w~ich may be regulated by an adjustable control, the
shunting of the effluent is halted, and the pumping via pump 18 proceeds with
all of the effluent being conveyed to the line 38.
In systems which employ two pumps, such as pumps 18 and 20, or three or more,
to evacuate effluent from a tank, it can be arranged that, on start-up, the
act~vated pumps are rotated in turn, i.e, pump 18 one time, pump 20 the next
time, and 90 on.
A key to the inven~ion, of course is the connecting together, with shunt
piping 12 the parallel conduits 14 and 16, and interposing the valves 22 and
24 in the shunt piping. Clearly, then, only one of the valve3 22 and 24 has
to be operated to penmit fluid flow between the conduits 14 and 16, and ~he
complementary pump 18 or 20 turned on.
., .
While I have described my invention in connection with a speciflc embodiment
thereof, and by detailing given steps in the method of its practice, it is
to be clearly understood that this is done only by way of e~ample, and not
as a limitation to the scope of the invention as set forth in the objects
thereof and in the appended claims.
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