JPS603214B2 - automatic control valve system - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an automatically controlled valve system installed at the outlet of a weir, and in particular operates so that the flow rate represented by the water level in the downstream basin remains constant even if the water level in the upstream basin changes. Related to automatic control valve devices.

The rate of flow passing through a valve is proportional to its controlled cross-sectional area and proportional to the square root of the differential pressure between the upstream and downstream sides (proportional to head loss), so in order to obtain a constant flow rate, the controlled cross-sectional area of this flow must be It is necessary to make it inversely proportional to the square root of the differential pressure.

SUMMARY OF THE INVENTION It is an object of the invention to provide a valve arrangement whose control cross-section automatically adapts to the differential pressure, and which, in operation, derives its energy only from the pressure resulting from the load imposed by the upstream water level. I'm trying.

That is, the present invention provides an automatically controlled valve device installed at the outlet of a weir to adjust the flow coming from the upstream basin to a constant flow rate. a tube of fixed area containing a tubular jacket, the hollow lower part of which is partially immersed in the downstream basin and located opposite said upstream basin and a horizontal seat attached to a corresponding nozzle; , this lower part is connected to a hollow upper part having a larger cross-sectional area as a whole and increasing in cross-sectional area as it goes downward, so that the apparent weight of the shirt is determined by the water level in the upstream basin. The automatic control valve device is characterized in that the valve device changes as a function of changes in the flow rate to provide the valve valve with an open position corresponding to the constant flow rate.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to preferred embodiments illustrated in the accompanying drawings.

The drawing first shows the basin 1 on the upstream side of the water level 10.

It is required to discharge water at a constant flow rate from the upstream basin 1 to the downstream water stream 3. The upstream basin 1 is connected to the downstream water stream 3 via a duct terminating in a nozzle 2 . The nozzle 2 has at its end a horizontal seat 4 which acts as a valve seat, and beyond this a deflection plate 5.
is installed. A vertically symmetrical tubular valve member 6 with a vertical stud 6, which is a valve member cooperating with the seat 4, is arranged opposite to and above the seat 4.

This jacket 6, which is suspended from a support member 16 by means of a spring device 7, includes two opening parts. One end is the top end 8 and the other is the bottom end 18. The hollow lower part 9 of the jacket, partially immersed in the downstream basin, has a constant cross-sectional area and is located above the seat 4.

The upper part 12 exposed upwardly is closed at its bottom by a bottom surface 17. This bottom surface has a large cross-sectional area and contains a central orifice 14. - The bottom surface 17 and the top end 8 of the shirt sleeve are connected by a peripheral wall forming the upper part 12. The action of this shirt is as follows.

When the shirt cover 6 moves away from the seat 4, a flow of water is generated between the water in the upstream basin and the water in the downstream basin. The water level 15 in the water tank is equal to the water level 10 in the upstream basin minus the head loss of the joint duct. This water level therefore corresponds to the net loading day perpendicular to the deflection plate 5. The spring device 7 provides a variable vertical force that is a function of the position of the shirt sleeve.

When this is balanced, this force corresponds to the apparent weight of the shirt. That is, a pressure equal to the weight of the water existing between the original weight of the shirt and the hypothetical cylindrical body (indicated by a dotted line) formed by the upper extension of the lower part having a constant cross-sectional area and the peripheral wall of the shirt. It corresponds to the sum of . According to the invention, the upper part 12 of the shirt jacket has a variable cross-sectional area which is larger than the lower end which has a constant cross-sectional area.

This upper section automatically provides a stable position for the shirt's apparent weight as a function of upstream water level.
In this position, the entrance above the seat 4 corresponds to a constant discharge. The valve is hydraulically self-centering guided without friction or mechanical wear, which makes it very sensitive to changes in load. Additionally, the orifice 14 acts like a diaphragm to slow the exchange of water between the lower and upper portions of the jacket. The operation of the valve device of the present invention will be further explained as follows.

The upper part 12 of the shirt sleeve 6 has an inner flap D, which is larger over its entire length than an inner flap D2 of the cylindrical lower part 9.

Therefore, the weight of the water within the shirt sleeve 6 is greater than the upward force applied to the shirt sleeve due to the water pressure at the bottom of the shirt sleeve. This upward force is equal to the product of the cross-sectional area (side/4·D≧) of the lower portion 9 of the shirt cover 6 and the water pressure applied to the bottom surface 17.

This upward force is also equal to the weight of a cylinder of water with a cross-sectional area equal to the cross-sectional area of the lower part 9 (below is the bottom of the lower part 9 and above is the water level 15 of the top 6). As a result, the weight of the water in the jacket 6 becomes slightly larger than the upward hydrostatic pressure. This difference corresponds to the weight of water in the annular region between the upper part 12 (diameter D,) and the dotted line drawn upwards from the lower part 9 (diameter D2). In the equilibrium state, the spring device 7 balances the weight of this difference plus the weight of the shirt sleeve 6 itself. The shape of the downward extension of the upper part 12 and the stiffness of the spring device 7 are selected in such a way that the gap between the bottom end 18 of the lower part 9 and the seat 4 is formed in such a way that a desired value of the flow rate is obtained. .

This is achieved by having the cross-sectional area of the upper part 12 decreasing upwardly, but always being larger than the cross-sectional area of the lower part 9. If the water level 10 on the upstream side rises now, the water pressure applied to the bottom surface 17 of the shirt cover 6 will increase, and as a result, the flow rate of water will first increase.

However, at the same time, the water leaked from the center orifice 1 of shirt Yu 6.
4 and increases the water level 15 in the jacket 6, resulting in the weight of excess water in the jacket 6 [upper part 1
The difference between the inner diameter of 2 and the inner diameter of the lower part 9 (D, -D2
)] increases. As a result, the shirt sleeve 6 lowers to a position where the spring device 7 is stretched and balances the increased force. This position is the new equilibrium position, in which the gap between the lower part 9 and the seat 4 is reduced, so that the water flow rate is the same as before. This will be further explained as follows.

That is, if the upstream water level rises by Δ days from the lower water level day shown in the drawing, the weight of the excess water increases by the annular portion 11 shown by the dotted line hatch. This increase is relatively large since it increases the rate of diameter increase at this level of the upper portion 12. Therefore, the weight increase of the water is large, and the length of the spring device 7 changes greatly, so that the gap between the bottom end 18 of the lower part 9 and the seat 4 is greatly reduced, and the flow rate becomes constant. If the water level on the upstream side increases from the upper water level day 2 by the same amount of △ days as mentioned above, the increase in the weight of water in the shirt tank is relatively small as shown by 11', and therefore the space has already become narrower. The amount of change from the gap is also small, and the flow rate remains constant.

Although the present invention has been described above in detail with reference to the preferred embodiment thereof illustrated in the accompanying drawings, the present invention is not limited to this specific embodiment, and many changes and modifications may be made without departing from the spirit of the invention. Of course you can get it.

[Brief explanation of the drawing]

The drawing is a longitudinal sectional view of a preferred embodiment of the present invention. 1... Upstream basin, 2... Nozzle, 4... Seat, 5...
Deflection plate, 6... Shirt cover, 7...'', imitation bag counterfeit, 8... Top end, 9... Lower part, 12.
... Upper part, 14 ... Orifice, 1
6...Support village, 17...Bottom.

Claims (1)

[Claims] 1. In an automatically controlled valve device installed at the outlet of a weir to adjust the flow coming from the upstream basin to a constant flow rate, both ends 8,
18 opens and includes a vertical tubular shutter 6 suspended from a spring device 7 with a force relationship that is a function of the displacement, partially immersing its hollow lower part 9 into the downstream basin 3 and connecting it to said upstream basin 1. of a constant cross-sectional area, located opposite a horizontal seat 4 attached to a nozzle 2 that communicates with the nozzle 2; connected to a hollow upper part 12 of increasing cross-sectional area so that the apparent weight of the shutter changes as a function of changes in the water level 10 in the upstream basin to give the shutter an open position corresponding to the constant flow rate; An automatic control valve device characterized by: