Device for the regulation of a constant outflow from a liquid container

The invention concerns a device for the regulation of a constant outflow from a liquid container, in particular from a rain reservoir, with an outflow opening for the liquid, wherein to the outflow opening is assigned a movable throttle element, which in dependence on the liquid level regulates the outflow of the liquid from the container. According to the invention, it is proposed that a component part (2) that is form-changeable in dependence on the fluid pressure control the throttle element, wherein takes place the stopping-down movement of the throttle element against a restoring force (spring 5). A device of this sort makes possible a regulation of a constant outflow from a fluid container, without requiring for this the use of a float.

BACKGROUND OF THE INVENTION 
The invention concerns a device for the regulation of a constant outflow 
from a liquid container, in particular from a rain reservoir, with an 
outflow opening for the liquid, wherein to the outflow opening is assigned 
a movable throttle element, which in dependence on the liquid level 
regulates the outflow of the liquid from the container. 
Devices of this sort for the regulation of a constant outflow from a liquid 
container are known from the state of the technology in manifold types and 
styles. For the most part they make use of a float that follows the liquid 
level and operates the throttle element by way of a rod or the like. 
In order to achieve a constant outflow from a liquid container, the outflow 
opening must be varied in dependence on the liquid level in the liquid 
container. In this the hydraulic relation governs according to the 
following formula: 
EQU Q=.mu.+A+.sqroot.(2+g+H) 
in which the symbols represent: 
Q outflow 
.mu. flow coefficient 
A passage area of the outflow opening 
g acceleration of the Earth 
H dammed-in height in front of the regulating element 
p pressure. 
It is apparent from the formula that the area A, in dependence on the 
dammed-in height H, must be varied in order to maintain a constant 
outflow. 
From DE 34 18 348 A1 a device is known of the type mentioned at the 
beginning that exhibits a regulator chamber with an inlet opening, with a 
first throttle element assigned to this, and also with an outflow opening, 
with a second throttle element assigned to this; in which device the two 
throttle elements are linked to each other so as to be fixed as regards 
rotation and are driven by a common float arranged in the regulator 
chamber. This sort of design of the device permits blockages in the region 
of the inlet opening of the regulator chamber to clear automatically. 
Known from DE 39 14 702 A1 is a float-actuated device for the regulation of 
a constant outflow from a liquid container, in which device there is 
likewise present a regulator chamber with inlet- and outflow openings, 
with throttle elements assigned to these. A float arranged in the 
regulator chamber controls the course of the two throttle elements via 
control curves. This device is also suited for clearing blockages in the 
region of the inlet opening to the regulator chamber automatically. In 
addition, the regulator chamber is formed there as a bell. The airtight 
closing leads, in the event of a damming-in of liquid in the regulator 
chamber, to a compressing of the air found there and thus to a reduction 
in the maximum achievable liquid level in the outflow amount regulator, 
which can thereby build relatively little. 
The disadvantage of the float construction for the regulation of a constant 
outflow from a liquid container is to be seen in the tall construction and 
consequent high cost, and further in the circumstance that with float 
constructions no high damming levels can be controlled, because the 
regulation of the constant outflow is limited by the maximal float 
position. 
SUMMARY OF THE INVENTION 
It is the task of the present invention to produce a device for the 
regulation of a constant outflow from a liquid container that, in a 
compact design without floats, permits a regulation even in the case of 
high damming levels. 
The task is fulfilled in a device of the type mentioned at the beginning by 
having a component part, whose form is changeable in dependence on the 
liquid pressure, determine a course for the throttle element, whereupon 
the stopping-down movement of the throttle element ensues. 
In this, according to the invention, the change in pressure, in consequence 
of a changed liquid level, at a defined point in the system taking up the 
liquid or through which it is flowing, is used to effect a change in the 
form of a component part located in the liquid, whereupon this change in 
form, by virtue of the controlling of the throttle element via the 
form-changeable component part, effects a stopping down of the outflow 
opening. In this the form-changeable component part is positioned 
advantageously in the container, i.e. in the region of the upper water and 
thus regulates the outflow by virtue, in particular, of the liquid level 
present there. 
The form-changeable component part can be fashioned in the most various 
ways. For example, an elastic component part is suitable, which is 
compressed in consequence of the acting liquid pressure and thereby 
actuates the throttle element, the elastic restoring forces producing the 
effect that the form-changeable component part, upon a reduced pressure, 
i.e. upon a lowered liquid level, again extends itself and that the 
throttle element stops down the outflow opening less. The form-changeable 
component part can also be formed as a hollow body, in particular with air 
located in the interior of the component part. The restoring forces can be 
produced from the elasticity of the component part or through an 
additional spring or air, which, in particular, are effective in the 
inside of the component part. In principle the form-changeable component 
part can be designed in the most various ways, for example as an elastic 
sphere, a balloon-like component part, a cylinder with two cylinder halves 
movable relative to each other and sealed off from each other, a bellows 
with a restoring spring, and so on. 
The invention is not restricted to having the form-changeable component 
part be controlled only in dependence on the liquid pressure in the 
container. It is quite possible to use the pressure prevailing subsequent 
to the container for the control of the form-changeable component part. 
This pressure prevailing subsequent to the container can be, for example, 
the ambient pressure or the pressure of the lower water, i.e. the water 
pressure that prevails behind the outflow opening (backwater). 
A special design of the invention under consideration plans a 
form-changeable hollow component part whose interior is linked to a 
pressure level different from the outer pressure level of the component 
part. With respect to construction, this can result, for example, from 
designing a line that links the interior of the form-changeable component 
part to the ambient pressure or to the pressure of the lower water. 
A further exertion of influence on the regulation of the outflow from the 
liquid container can be achieved if the form-changeable component part and 
the throttle element, which is formed, for example, as a gate, are 
surrounded by a bell with an inlet opening. Between the inlet opening of 
the bell and the outflow opening, an axis offset can also be planned, 
whereby a turning around of the liquid in the bell takes place, having as 
a consequence a, destruction of energy. Through this, the pressure in the 
bell increases, and thus arises a greater force for the moving of the 
form-changeable component part. In order to be able to remove blockages of 
the inlet opening of the bell, the inlet opening should also be assigned a 
throttle element movable by means of the form-changeable component part. 
In order to be able to bring about an exact regulation of the constant 
outflow, the form-changeable component part should control the throttle 
element or elements via a control curve/control disc. A bell, by the way, 
makes possible the installation of the regulation device also outside of 
the liquid container, for example in a after shaft or as an intermediate 
component part in pressure lines ("dry installation" and "underwater 
arrangement" respectively). 
With very small outflows, the throttle elements must already in the 
starting position, without a damming-in of the inlet- or outflow openings, 
stop down both of these somewhat, in order not to get an excessive outflow 
at an incipient damming-in. As an additional installation for small 
outflows, a drive should be designed that makes possible the shifting of 
the base of the form-changeable component part in a direction 
perpendicular to the liquid surface. Finally, a mechanism can be planned 
for the adjustment of the restoring force of the form-changeable component 
part. 
Further features of the invention are represented in the dependent claims, 
in the description of the figures, and in the figures themselves, it being 
remarked, that all of the individual features and combinations of 
individual features are essential to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIGS. 1 and 2 show the outflow region of the rain reservoir. Illustrated 
are the basin bottom 20 with the basin floor 21 and the outflow-side wall 
22 with the outflow opening 1. Slightly above the outflow opening, a 
bracket 23 is attached to the end wall 22 inside of the reservoir. The 
bracket 23 displays an approximately horizontally-aligned support plate 
24. Between a section of the support plate 24 and the outflow wall 22, a 
throttle element in the manner of a gate is led through, the plate-shaped 
gate body being positioned immediately next to and parallel to the end 
wall 22 and being vertically movable. The gate 3 shows, in the 
cross-sectional view of the rain reservoir, a rectangular surface. The 
upper region of the gate 3 is provided with a plate-shaped support 
extension 25, which extends above and parallel to the support plate 24 of 
the bracket 23. Between the support plate 24 and the support extension 25, 
a bellows 2 is arranged that in the regions of its two end surfaces is 
joined to the support plate 24 and to the support extension 25 
respectively, in a manner not further illustrated. The bellows 2 encloses 
an interior 26, in which a spiral-shaped pressure spring is arranged, 
which rests against the support plate 24 and the support extension 25 and 
thus strives to press these apart. In the interior 25 of the bellows 2, 
the ambient pressure P.sub.u prevails. This is achieved by means of a 
ventilation line 4, which is connected at one end to the interior 26 of 
the bellows 2 and whose other end runs above the maximum liquid level of 
the upper water, i.e. of the water to be found in the rain reservoir 27. 
Also shown clearly in FIG. 1 are the dammed-in height H in front of the 
gate 3, the upper water pressure p.sub.1, the free opening height Z.sub.1 
of the outflow opening 1, and the water pressure p.sub.3 of the lower 
water, as well as the fluid levels of the upper water and the lower water 
at some point in time. The flow direction of the water is illustrated by 
means of the arrow 28. 
A regulation of the outflow, in accordance with the equation mentioned at 
the beginning, comes about in a simple manner when the bellows 2, by which 
is also meant in the broadest sense a compensator, a spiral tube, or the 
like, is compressed upon a rise in the upper water level and therewith of 
the upper water pressure p.sub.1, and the gate 3 is moved downward. The 
air in the bellows 2 is in the course of this emitted via the ventilation 
line 4 into the surrounding air. Upon a falling upper water pressure 
p.sub.1, the gate is again moved upward, either through the inherent 
spring force of is the bellows 2 or, referring to the present design 
example, through the pressure spring 5, whereby the gate 3 is raised again 
and the passage area A of the outflow opening 1 is enlarged. 
The component parts shown in the variants according to FIGS. 3 through 12, 
corresponding to the component parts of the variant according to FIGS. 1 
and 2, are marked, for the sake of simplicity, with the same reference 
numerals. 
FIGS. 3 and 4 show a variant that makes it possible to remove a blockage of 
the outflow opening of the regulation device. This is achieved by mounting 
the structure illustrated in FIGS. 1 and 2 under a bell 6, and by 
positioning an additional throttle element in the manner of a gate 8 at 
the inlet opening 7 with the free opening height Z.sub.7 of the bell 6. 
This gate 8 is rigidly connected to the outflow gate 3. When the upper 
water level rises, there appears inside the bell 6 a pressure p.sub.2 that 
is equal to approximately one-half of the upper water pressure p.sub.1. 
The bellows 2 is compressed by the pressure p.sub.2 and the gates 3 and 8 
are moved downward. 
Now if a blockage takes place, it will appear at the gate 8, since this 
gate represents the first cross-sectional narrowing on the regulation 
device. Through the diminished inlet the bell 6 depletes itself via the 
outflow opening 1. The pressure p.sub.2 becomes approximately equal to the 
pressure p.sub.3, whereby the bellows 2 expands to its original length. 
The gates 3 and 8 are lifted and the blockage is flushed out. After that, 
there again appears in the bell 6 a pressure of about half of that of the 
upper water p.sub.1, thus p.sub.2. The regulator again goes into the 
regulation position. In the design form according to FIGS. 3 and 4 with 
the bell 6, in addition to the ventilation line 4 of the bellows 2 there 
is designed a ventilation line 34 connected to the bell 6. In consequence 
of the venting of the bell 6, the flow through the regulator is diminished 
by means of eddy processes. Through this means it is possible to open up a 
large aperture with equal flow-through, thereby reducing the danger of 
blockages. 
It is clear from the equation given at the beginning that, for example, 
upon a doubling of the water level, the outflow area in each case should 
be reduced only by a factor of 0.71, not 0.5, if the outflow Q is to 
remain constant. This root function is only poorly realizable in a 
technical application with the constructions described in FIGS. 1 through 
4, because the spring rates of a bellows or else of an supplementary 
spring are as a rule approximately linear. A design of the device 
according to the invention that takes into consideration the root function 
in regulating outflow is illustrated in FIGS. 5 and 6. There the bellows 2 
is arranged horizontally and provided with the pressure spring 5 inside. 
The ventilation line 4 of the bellows interior 26 comes out in the 
discharging channel 29. The bellows 2 is located under the bell 6. Upon 
compression of the bellows 2, two control discs 9 and 10 are shifted 
horizontally. Milled into these control discs is in each case a guide 
groove 30, which carries over the linear movement of the bellows 2 to a 
root-function movement of the vertically-movable supported gates 3 and 8. 
The transferring of the movement to the gates comes about, for example, 
through rollers 11 that are attached to the gates 3 and 8. 
Essential to the variant illustrated in FIGS. 5 and 6 is that in the event 
of a backing up into the ventilation line 4 of the bellows 2, i.e. with a 
pressure relation p.sub.3 &gt;p.sub.u, the bellows, corresponding to the 
backing up, is pressed apart. Regulation thus ensues according to the 
pressure difference between the upper water p.sub.1 and the lower water 
p.sub.3 with a constant outflow. This means that a regulator conceived in 
this way reacts even to backups and automatically regulates in 
correspondence to the pressure difference. 
The regulation device illustrated in FIGS. 5 and 6 ensures a constant 
outflow no matter how high the water climbs. In this, the outflow is 
changeable through the insertion of various control discs 9 and 10. A 
self-actuated opening takes place upon blockages, as well as automatic 
recognition of backups and appropriate proportional regulation. The 
regulation device is constructed in a very compact manner and can be 
installed alternatively either in front of or behind the wall opening. 
FIG. 7 shows a mechanism 12 for the adjustment of the pre-tension of the 
pressure spring 5 of the bellows 2. Through this adjustment of the spring 
pre-tension, the outflow of the regulator can be fine-adjusted. 
FIG. 8 shows an axis offset between the inlet opening 7 of the bell 6 and 
the outflow opening 1, with the dimension X. By means of this there takes 
place in the bell 6 a circulation of the water, which has as a consequence 
an energy destruction. Through this the pressure p.sub.2 in the bell 6 
increases to above half of the upper water pressure p.sub.1. Thus there is 
produced a pressure p.sub.2 for the moving of the bellows 2 that is 
greater than the pressure p.sub.2 that would appear there without the axis 
offset. The area of the inlet opening 7 should always be greater than that 
of the outflow opening 1. By this means, the pressure in the bell 6 is 
increased further with reference to the pressure that would appear with 
equally large inlet- and outflow openings. FIG. 9 illustrates that the 
maximum opening height Z.sub.7 of the inlet opening 7 should always be 
smaller than that of the outflow opening 1, so that any possible blockage 
will occur at the inlet opening 7, whereupon an automatic opening will 
take place. 
With very small outflows, the gates in the starting position already stop 
down somewhat the inlet- and outflow openings without a damming-in, in 
order not to get an excessive outflow at an incipient damming in. Upon a 
possible blockage, the structure illustrated in FIGS. 5 through 9 then 
opens likewise only to this gate starting position. As an additional 
device for small outflows, according to FIG. 10 a further bellows 13 or 
some other movement system can be incorporated into the structure 
described above, in order to effect a shifting of the bellows 2. This 
comes about, for example, by means of arranging the additional bellows 13 
between a movable bracket 31, to which the bellows 2 is attached, and a 
stationary bracket 32, in particular a bracket attached to the end wall 
22. The bellows 13 expands only when the difference in pressure between 
the upper water p.sub.1 and the bell 6-p.sub.2 --exceeds a determined 
value. This is the case when on the upper water side a high pressure 
p.sub.1 is present, but the bell 6 has run dry owing to a blockage 
(p.sub.3 =ca. p.sub.u). In this case the bellows 13 would move and raise, 
additionally to the automatic opening of the bellows 2 described above, 
the gates 3 and 8 up to the fully open point of the openings 1 and 7. 
As is to be gathered from FIG. 11, in place of the additional bellows 13, 
an electric, hydraulic, or pneumatic drive 14 or the like can be attached, 
which if desired is also controllable by a remote-control system. With 
this, the regulator is also to operate via a remote-control system, i.e. 
to adjust the outflow or flush the subsequent channels. Going further, a 
drive unit 15, as is made clear in FIG. 12, can be attached to the 
adjustment mechanism 12, permitting the outflow of the regulator to be 
adjusted via a remote-control system. In principle the drive units 14, 15 
can also be operated manually. 
The regulation device with bell 6, designed fundamentally according to the 
representation in FIG. 3, is illustrated in FIG. 13, in which, however, 
this regulation device is attached to a further wall 33 outside the 
container 27. A pipe 32 connected to the outflow opening of the container 
27 leads the outflowing water, under the pressure p.sub.1, to the inlet 
opening of the regulator. In the regulator, the pressure p.sub.2 appears 
in precisely the same manner as in the design form according to FIG. 3. 
LEGENDS ON DRAWINGS 
FIG. 1: Upper water 
Lower water 
FIG. 2: Upper water 
FIG. 3: Upper water 
Lower water 
FIG. 4: Upper water 
FIG. 5: Upper water 
Lower water 
FIG. 6: Upper water 
FIG. 10: Upper water 
FIG. 11: Upper water 
FIG. 13: Upper water