Liquid apportioning device

A mechanism for selectively distributing liquid flow to at least two separate outlet conduits includes a tank for receiving liquid and at least two tubular members having bellows-like sections mounted in the tank in flow communication with the associated outlet conduits. Actuator devices are connected for selectively compressing or extending the bellows-like sections to determine the elevations of the mouths of the tubular members within, or above, the liquid in the tank to thereby control the flow through the outlet conduits.

BACKGROUND OF THE INVENTION 
Field of the Invention 
The present invention relates to a mechanism for distributing liquid flow 
and, more particularly, to a mechanism for selectively and concurrently 
distributing liquid flow to two or more separate outlet conduits. 
State of the Art 
In handling flowing liquids, including slurries, the need can arise for 
selectively and concurrently apportioning or "splitting" the flow among a 
plurality of separate conduits. One instance where such a need may arise 
is in filtration operations in a municipal wastewater treatment plant 
where filter machines are operated in parallel in order to dewater the 
total sludge produced by the plant. Although the rate of flow to each of 
the filter machines should be constant for best results, that is often 
difficult to achieve because the inflow to the plant may vary 
substantially, say by as much as fifty percent. 
In such applications, it is well known to distribute liquid flow to various 
streams by using so-called underwater valves. It is also known to utilize 
so-called "division boxes" whose sides comprise overflow weirs which are 
each associated with an individual discharge conduit. One drawback of 
division boxes, for instance, is that it is difficult to apportion or 
balance the flow over the various weirs. 
OBJECTS OF THE INVENTION 
A primary object of the present invention is to provide a mechanism for 
selectively and concurrently distributing liquid flow to at least two 
separate conduits. 
Another object of the present invention is to provide an improved 
apportioning mechanism for distributing selected volumetric rates of 
liquid flow to two or more separate conduits.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Generally speaking, the illustrated mechanism includes the following 
elements: a tank 11 for receiving liquid emitted from an inlet pipe 12; a 
plurality of separate outlet conduits 14, 15 and 16 connected to the tank 
in flow communication with the liquid therein; and means such as 
designated by the bracket 18 to selectively distribute liquid from the 
tank to the individual outlet conduits. 
Speaking more particularly of the illustrated embodiment, the tank 11 is a 
box-like structure having a bottom wall 21 and upstanding sidewalls 22-25. 
(The forward sidewall 25 is partially cut away in the drawing to show the 
structure internal to the tank). Preferably, the tank is open to the 
atmosphere. It should be noted that the aforementioned inlet pipe 12 is 
mounted to extend through the sidewall 24 of the tank, but various other 
means could be provided to supply liquid to the tank. 
In the illustrated embodiment, the aforementioned outlet conduits 14-16 are 
positioned to extend upward into the liquid in the tank 11 with their 
upper ends terminating a substantial distance below the surface of the 
liquid. Although those outlet conduits are shown as being sealingly 
mounted through apertures 28-30, respectively, formed in the bottom wall 
21 of the tank 11, it should be recognized that the apertures for the 
outlet conduits could just as well be formed through one of the lower 
sidewalls of the tank. 
Mounted within the tank 11 in generally upright positions are open-ended 
tubular members, generally designated 33-35, respectively, whose lower 
ends are sealingly connected in flow communication with the upper ends of 
the respective outlet conduits 14-16. According to the present invention, 
each of the tubular members includes a compressible bellows-like section 
39 which allows the effective length of the tubular member to be 
selectively varied. In practice, the bellows-like sections 39 are flexible 
rubber boots or the like. Preferably, frusto-conical funnel-like members 
43 are sealingly connected to the upper ends or mouths of each of the 
tubular members to admit liquid from the tank 11 into the tubular members 
without undue turbulence. 
Across the top of the tank is mounted a beam 46 or similar structural means 
to stationarily support actuator devices 51, 52 and 53, which are 
associated with the tubular members 33-35, respectively. The actuator 
devices 51-53 are connected to the tubular members 33-35, respectively, to 
selectively compress or extend the bellows-like sections 39 to thereby 
determine the elevation of the upper ends of the tubular members within 
the body of liquid held in the tank 11. Each of the actuator devices can 
be understood to include a selectively positionable solenoid or, as 
illustrated schematically, a double-acting piston and cylinder mechanism 
operated by compressed air, hydraulic fluid or the like. It should be 
observed that the pistons of the actuator devices in the illustrated 
embodiment are fixedly connected, via rods 45, to the funnel members 43. 
In operation, the rods 45 are reciprocated in a vertical direction by the 
actuator devices 51-53 so that the vertical elevations of the mouths of 
the funnel-like members 43 can be independently and selectively 
determined. The elevation of the mouths of the funnel-like members 43 
within the liquid contained in the tank 11 in turn determines the flow 
into the respective outlet conduits 14-16. When any one of the funnel-like 
members is elevated above the liquid level in the tank 11, as is the 
funnel member to the far right in the drawing, there is of course no 
liquid flow into the associated outlet conduit. 
One particularly advantageous application of the aforedescribed 
apportioning mechanism is in conjunction with gravity filters in water or 
wastewater treatment plants. Generally speaking, gravity filters comprise 
confined layers of sand, gravel or other granular matter through which 
liquid flows by gravity for purification. When the aforedescribed 
apportioning mechanism is utilized in combination with two or more such 
filters, each of the actuator devices is connected to a conventional 
sensor element via a conventional positioning device; this is illustrated 
in the drawing by the sensor element 59 connected to a positioning device 
which, in turn, is coupled to the actuator device 55 via pneumatic lines 
51 and 53. Each sensor element is employed to sense the liquid level in an 
associated gravity filter. In operation, the positioning device to which a 
sensing element is connected acts upon signals from the sensing element to 
control the associated actuator to thereby determine the elevation of the 
mouth of the associated tubular member in the tank 11 and, hence, to 
control the liquid flow to the gravity filter wherein the sensing element 
is located.