SU55478A1 - A device for measuring the flow of fluid in weirs - Google Patents

Description

The present invention aims to satisfy the need for irrigation water metering devices in areas that irrigate agricultural and industrial crops.

This need can generally be met with a water meter, which measures the costs of branching off a part of the flow with, for example, a paddle wheel rotating under the action of a fluid stream and provided with a tray for receiving a liquid.

But usually, irrigation water is counted as follows. The Chipoletti or Thomson weir or the metering gauging station for spinner measurements is installed on the channel at the desired point, and the flow of water passing through this point of the channel is measured three times a day.

Such a method, however, is clearly unsatisfactory.

The proposed water meter operates continuously and gives direct indications of the water flow on the meter of any known device. To do this, it uses a disk rotating by the force of a jet of fluid.

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and provided with a tray for receiving a liquid, in the same way as is done in devices for sampling liquids.

However, in such devices, a change in the amount of flowing fluid causes a change in the speed of rotation of the disk, and this speed can be changed by changing the slope of the blades.

In the device according to the invention, the rotational speed of the disk is kept constant, for which the water jet driving it is supplied from a separate tank, in which a constant water level is maintained. The stream of water supplied to the device for the purpose of measuring the flow through the hole in the weir, depending on the pressure, falls on a radially located tray the closer to the center of the disk, the greater the water pressure. Therefore, at a constant number of revolutions of the disk, the amount of fluid collected depends on the distance of the jet and the speed at which it expires.

On the other hand, it is known that if we construct the curves of water consumption versus head for an open weir and for a hole in its wall, we lay the head along the ordinate axis, and the water flow along the abscissa, then the flow curve for the weir will be convex upward (solid line Fig. 1 of the drawing), the curve for the hole is a bulge downward (dotted line in Fig. 1 of the drawing). Thus, in order to obtain a linear relationship between the flow of water through the weir and through the round hole, it is necessary to take into account not all the water passing through the hole, but only a part of it, the greater the greater the water pressure above the weir threshold and hole.

All these points should be taken into account in the device so that, despite the water supply to it through the hole in the shield, it gives a real flow rate of liquid in the weir with any change in pressure.

For this, a device for measuring fluid flow in weirs using a disc rotated by a fluid jet and provided, as mentioned above, with a fluid receiving tray according to the invention, the tray is shaped in such a way that the amount of fluid it collects at the time of jet intersection is pre-selected dependence on the jet departure distance determined by the pressure in the overflow that is taking place at the moment.

In FIG. 1 shows a diagram of the dependence of water flow from the naf-fa for the Chipoletti weir and for the round hole in the shield of the water drain, which is described above; FIG. 2- is a section of the device, according to the invention, along the line AB of FIG. 2; FIG. 3 - - view of the device in the plan.

From the weir pacifier, water through a removable piece of tube 1, the inlet opening of which is protected by a set; oh, is fed into the device through two Oi worsts. Through one of them, through CTei.jINNAY tube 2, water flows directly onto the tray 6 device; and through the second into the open CR. i: xy flat reservoir 5, B CAT. YM water level remains all vr-- I am constant and. from which

on a horizontal tube 4, directed at an angle to the radius of the disk 5, the water flows out, causing the disk 5 to rotate at a constant speed, since the pressure above the tube 4 is limited by the upper open edge of the tank 3, which discharges excess water into it. When the disk 5 rotates on its axis, the tray b mounted on the disk 5 gets that part of the water coming through the tube 2, which part of the circumference is the width of the tray at the intersection of the falling stream of water with it. Since the flow of water from the mouth of the tube 2 depends on the flow rate and will be the greater, the greater the water pressure above the tube, at low water pressures, the stream from tube 2 will fall to the edge of tray 6 closer to the tube, and as the nanorine increases it will increasingly approach the axis of the disk 5. From tray b, through the opening 7, water flows into the vessel 5, in which a flat siphon 9 is fastened, the lower end of which goes out and is constantly filled with water falling from the disk 5. As soon as vessel 8 napolits, siphon 9 discharges water into the open top Vuchik W attached to an inclined axis. Under the water, the tank turns in the direction indicated by the arrow and the spring attached to the same axis turns the gear wheel 12 by one tooth. When water from the tank 10 flows out through the hole 13 in its bottom, the lead weight 14 causes it to return to the former place.

Thus, the device takes into account only the water that falls on the tray 6.

At a constant size of the area of the hole 2, the change in water flow through the latter depends on the change in the rate of its flow, and depending on the flow rate the water flows to the tray at different distances from the hole 2. But since only the water falling into the tray is taken into account 6, the width of the latter in the place where the jet falls should be such a part of the circumference described by this part of the tray around the axis, which part of the water flow from the hole 2 must be taken into account, which can be completely freely achieved by giving tray 6 of the appropriate configuration.

FIG. Figure 1 shows two curves of flow rate Q versus head pressure N. Of these, the upper curve shows this relationship for the Cipoletti weir, and the bottom is the length of the round hole 2 in the 0.4-mm shield.

If you set, for example, the goal is to take into account the water entering through the hole 2, so that each 1 liter passing through the weir corresponds to 0.4 cm of the recorded water and that this ratio is maintained at any H of water above the weir threshold, then with a vessel capacity of 8 about 400 cm each siphoning of its siphon will correspond to 1 m of water that has passed through the weir. But in order for the above ratio to be maintained at any H, it is necessary to regulate the flow of water into vessel 8 so that the volume of water taken into account depends on H on the upper curve, and not on the lower one. For this purpose, for each given H only the relevant part of the water entering through the opening 2 into the device should be taken into account. For example, with H 1 cm, instead of the incoming 5.3, one should take into account 1.07 or 4.95 times less; with H 8 cm

instead of 11.94., - 8.43 or 1.42 less. For this purpose, tray 6 is shaped as shown in FIG. 2

The subject matter of the invention.

Claims (4)

1. A device for measuring fluid flow in weirs using a disk rotated by the force of a jet of fluid and provided with a tray for receiving a fluid, characterized in that the tray 6 is shaped so that the amount of fluid it collects when it crosses the stream flowing out of the hole 2, was in a pre-selected dependence on the jet's flight distance, determined by the pressure in the weir that is taking place at the moment. 2. In the device according to claim 1, use the measuring vessel 8 for collecting the liquid flowing out of the tray 6 through the opening 7. 3. In the device according to claims. 1, 2, use siphon 9 to empty the measuring vessel 8. 4. In the device according to claims. 1, 2, 3 use of a JO vessel with holes 13 fixed on an inclined axis, equipped with a counterweight 14, and designed to pass water pumped out by siphon 9 from the measuring vessel 8, in order to take into account its quantity by the counter 12, which is activated during each turn vessel 10, carried out under the influence of water falling into it from vessel 8. to the author's testimony of P. P. Utkin No. 55478 . f) -Q ..fig.