SU1760A1 - Instrument for measuring the difference in water levels, flow rates and slopes - Google Patents

Description

The proposed device for measuring the difference in horizons, flow rates and slopes of water is designed to increase the accuracy of measuring differences in water levels to practically acceptable limits, use the Pitot tube: measure average and low flow rates, which cannot be measured even with a spinner, and eliminate the insufficient accuracy of the Amsler instrument for water slope measurements.

In addition to the laboratory use of the instrument for these measurements, it also provides an opportunity to measure with sufficient accuracy the flow of water in small streams and channels with a slow flow, where the spinner is inapplicable, makes it possible to study the distribution of velocities and pressures in pipes, etc.

FIG. Fig. 1, 2 shows schematically the measuring part of the device in two positions: in the working (Fig. 1) and in the preparatory (Fig. 2), in conjunction with the supply part of the device; in fig. 3 shows the setup diagram of the device during measurements; in fig. 4, 5 shows the measuring part of the device on an enlarged scale; in fig. 6 is a longitudinal section along the CD of FIG. five; in fig. 7, 8 — detail of the supply unit; in fig. 9-detail device crane 3; in fig. 10 is a detail of the hoist winch device and in FIG. 11 is a component of a device for connecting a measuring device with an inlet part.

The proposed device (Fig. 1) consists of the measuring part 3–13 and W3 of the supply part 38–48, connected with rubber tubes 7, 2, 14, 19; this device is depicted as applied to the measurement of flow rates.

The measuring part of the device (Fig. 1. 2, 4 and 5) consists of two parts: J, 4, 5 and 8-13, connected by water metering tubes 6, 7, of which the first (bottom, fig. 1) part 3-5 consists of two chambers 4, 5, and the upper part is 8-13 V13 four chambers 8, 9, 10 and 11.

Water from tubes 1 and 2 goes sequentially through valve 3 and chambers 4 and 5 to water meter tubes 6 and 7, which at the end are branched and pass: tube b into chambers S and 9, and tube 7 into chambers 10 vi 11 (see .Cut .4B). Chambers 8.9, 10 v (11 ъ cross section is exactly the same and are located exactly symmetrically around a common vertical axis of symmetry 00.

At the top of the BCg, the chambers with a common valve 12 can be connected or disconnected. The tap 3 is arranged so that the water from the tubes 1 and 2, from each, individually, can be communicated with a measuring instrument either through a large opening, or through a small, or completely separated. To protect against unequal heating, the device is enclosed in a common casing filled with water and consisting of two parts 73 and 20 connected by a tube 2 /. The inner space of the housing with the supply part is connected with a rubber tube 14, and with the inner space of the chamber tube 15 with a valve 16. This connection is made for filling the devices with water. For this purpose, there are also three tubes 17, which connect the chambers 4, 5 to the inner space of the casing through a tap / 5 to the tube 79, which is connected to the air space of the inlet part where there is a vacuum.

The filling of the measuring instrument with water is already done after the supply part is filled with water (as the supply part is filled with water, as set out below). For this, the device is inverted as shown in FIG. 2. Crane 3 is closed and taps 72, 16 and 18 are open. With this position of the device, the water will begin to fill the casing and the chambers. When it reaches a certain height in the water glasses, the taps 76 and 18 are closed, the device is put in the straight position (Fig. 1). this is the end of the preparation of the device.

After the appliance is ready for operation, the valve 3 opens to a large opening and is left in that position for some time so that the water horizon in the chambers is approximately aligned. Since the internal space of the device is hermetically sealed, water cannot flow out from there, and only a definite quantity according to the Boyle-Mariott law will leave the device depending on the pressure ratio in the device at its direct position and inverted. For the same reason, if in one tube the horizon of water rises somewhat, in the other it decreases as much. When the water horizons in the chambers are approximately equal, the valve 3 is placed on a small hole and left in this position for some time. This is done to eliminate the effects of pulsation, waves, jolts, etc. Since only a small amount of water can penetrate through a small hole in a short period of time, a horizon that does not correspond to this area and a medium for some period of time will be established in the chambers. After a certain time, the taps 3 and 72 are closed and the device is reversed to FIG. 2. If there was air in the upper chambers equal to the volume of chambers 4 and 5, then, after inversion, the air from the upper chambers will go to chambers 4 and 5, and the water horizon will set at a certain height in the water glasses. Pressure was applied on these glasses and it was predetermined in advance exactly what height in the upper chambers the divisions on these tubes correspond to. For each tube there is a label in which heights of horizons are written out in the upper chambers, corresponding to each division of the tube.

In the device, every two communicating below, the chambers of 8 liters 9, 10 and 11 represent one common camera. And since both such double cameras have a common axis of symmetry, they can be considered as coinciding with each other. Therefore, with such a device, the error from the non-vertical position of the device will not depend on the distance between the cameras, as in the Pitot tube. When measuring small differences in the horizons of water, it can be considered, therefore, that the non-vertical position of the device does not entail any error.

Since the device aims to measure not the height of the horizon, but the difference in height, the same error in the measurements of each horizon will not entail any error in determining the difference. But since both pairs of cameras are almost identical, this. The effect of the reasons listed here will diminish. The device is protected from uneven heating by washing it in the casing.

The measuring device is presented separately in FIG. 4 and 5. Instead of one tube 21, as shown in the diagram, there are two arranged here for more convenient filling of the instrument. These tubes are metal and at the same time serve to fasten parts of the device. Rubber tubes 1, 2, 14, VI 19 are conveniently connected to a common tip and connected to the supply part as one piece. Separately, this tip is shown in FIG. /. Rubber tubes are put on metal tubes attached to plate 23. Another plate 25 is attracted to this plate with screws 24, in which holes are made corresponding to tubes 2, 14 and 19. In the recess between these plates is placed a piece of rubber 26, having also corresponding holes. With these holes, the tip is freely attached to the processes of the tubes of the measuring instrument; then the plate 25 is attracted by the screw 24, the rubber flattens from this and fits tightly against the connecting portions.

Crane 2 is shown separately in FIG. 6. The tap rod is pressed against the sleeve by means of a spring washer 27, the action of which is adjusted by means of a screw cap 28. The tap 3 is shown separately in a longitudinal and transverse section in FIG. 9. A small hole 29 is arranged in the rod. that it does not touch the walls of the sleeve so that the particles of the lubricant do not block it. There is an index of 35 on the casing for mounting the crane to various positions, and a dash with corresponding designations on the valve. The flow tubes b and 7 (Figs. 4 and 5) for cleaning are taken away from the instrument and the connection is of the same type as described for the connection with the supply part. The lower connection is shown in section in FIG. 7-8. The tubes fit snugly around the chambers. If the task can be allowed when measuring large

values and a large error, the water tubes are not cylindrical, and the area of the holes in them has a flattened cross-section in shape for better air flow during the transfusion. Chambers 4 and 5 are arranged in such a size that when the device is turned upside down, when the horizon in the tube b is at the top, it should be in the tube 7 below and vice versa. With such a device, the entire length of the flow tubes and the scale length are equal to the length of the two flow tubes for disposal. Metal parts 36 are attached to the body of the casing and the crane 3 (Fig. 4 and 5), which are pivotally connected to the plug 37. With the help of a nut 35, the device can be fixed in a straight position or upside down. The plug 37 is inserted into the corresponding receptacle slots 59 (Fig. 10) and secured thereto by a screw 64.

The device for the supply part is shown in schematic drawing 1. If the device is intended to measure the flow velocity, the supply part is a device similar to a Pitot tube.

Water from the test point to the device is supplied through two tubes 38 and 39 (Fig. 1), the purpose of which is the same as in the Pitot device. But since here the measuring device remains constant at the same height above the surface of the river, so that you can measure the speed at different points of the vertical, the tube 39 moves inside the tube 40, which remains stationary. At the surface of the water, the tubes 39 and 40 are tightly interconnected after the tube 39 is installed at the desired depth. The 3S tube remains stationary, since the level in it does not depend on the depth to which it is lowered. To protect against uneven heating, both tubes are surrounded by a common housing 47 filled with water. At the top, the casing passes into the reservoir 42, having a volume somewhat larger than the volume of the casing of the inlet part and the measuring device. In the casing is arranged

valve 43 for filling the supply part.

Tubes 38 and 40 of the income t almost to the top of the vessel 42 and at the top open. A narrow tube 44 is separated from the top of the vessel 42, which is connected (via a common tip) with a rubber tube 79 of the measuring device. From the tubes 40 and 4J, the metal spikes 45 and 46, which go to the measuring device, are separated to the side. A metal spike 47 is separated from the casing, which is connected to the rubber tube 14 of the measuring device.

Before filling with water, a measuring device is attached to the inlet part. Then the valve 43 is opened, the supply part is turned over and the tank 42 is lowered into the water. When the water through the valve 43 fills the tank 42, the valve 43 is closed and the supply part is turned and set straight (Fig. 1). the ends of the tubes and the housing should be in water. Then the air from the tubes and casing rushes up and fills part of the tank 42, and its test is filled with water, which partly pours out. Since the entire device is sealed, a vacuum is formed at the top of the tank 42 and the water in the tank is set at a certain height. After filling the measuring device (described above), part of the air from the measuring device through the tube 44 will go into the tank 42, the water in it will decrease to set at such a height that the ends of the tubes 38 and 40 will be above the surface of the water in the tank 42. To observe the horizon water in this tank tube 44 is connected to a mercury gauge of the simplest design 48. If all the connections are tight enough and after filling the device cannot penetrate the air, the pressure gauge is not necessary, since the water horizon in the vessel 42 will remain on estimated height. After filling the inlet part, the device is ready for operation. In this form, it can be transferred to another place at the end of one measurement and it will not be necessary to fill it again if the ends of the tubes were all the time in the water during the carrying.

With this arrangement, all the parts of the supply tubes are all the time straight and vertical. If they are thin enough, the air bubble in them cannot be held to fill everything in any place. section. And such a bubble, which does not violate the continuity of the water column of the tube, cannot have any effect on the height of the horizon in the tubes. Since the processes to the measuring device go to the side, an air bubble that has accidentally entered the downstream part cannot penetrate into the measuring device, but will pass into vessel 42 and cause only more or less but the same decrease in the horizon in vessel 42 and in the tubes 38 and 40, and this will not reflect on the measuring instrument, since it is separated from the reservoir 42 by means of a crane 75.

A general view of an instrument installed to measure water flow rates is shown in FIG. 3. The supply part together with a measuring device attached to it with clamps 50 is mounted on rod 49. A gear rail 63 is arranged on the rod, along which the device can be moved with the help of a winch 57 attached to the body of the inlet part. The winch is separately shown in FIG. 10. In the same figure, sockets 59 are visible, into which a plug is inserted to hold the measuring device and branches 44, 45, 46 and 47 from the tubes to the measuring device.

The tube 38 is shaped for convenience flattened form. The connection of tube 39 and 40 is shown in section in FIG. 8. A calyx 54 is attached to the rod 53, into which a rubber ring 56 is inserted. A rod 53 can be pulled upwards with a screw 54 (Fig. 3) and thus squeeze the rubber ring between the cup 54 and the plate 55 (Fig. 10), soldered to the tube 40. When the screw 54 is unscrewed, the tube 39 completely freely moves in the tube 40. After screwing the screw in, the rubber flattens and tightly connects the tubes 39 and 40. In FIG. 7 is shown

This connection is seen from the side and the connection of the tube 39 with the rod is also visible. To the end of the tube 39 is attached to the clamp 55, which wraps the bar. With the help of the string 57 and the crank 5. (fig. 3) the tube can be lifted up, and down it is lowered with lead load 60 (fig. 7).

To measure inclines, you can use the same instrument if you remove the tube 39 and insert the tube 67 instead (in Fig. 1 is shown in dotted lines). Tube 67 is about 4 meters in length and held in a horizontal position by a float 62. Its diameter is about 15-20 mm, therefore, if it is slightly tilted together with the device, the air will come out of the vessel 42. The principle of measuring the slope the same as in the Amsler device, but only the device itself is modified in accordance with the specific accuracy of the measuring device.

For reliable measurement, it is necessary that the continuity of the liquid column from the vertical point to the surface of the water in the measuring device is not violated anywhere by the air bubble. To achieve this, it is necessary that the tubes be wide enough, but if in any place the cross-sectional area of the tube cannot be made large, then its cross-section in this place should be made in the form of a narrow slit. Where the tubes do not run vertically, it is necessary that they are not too inclined. Tubes 74, 75, 77, 79 and 27 may be narrow, as they serve only to fill the instrument and do not affect the accuracy of the measurement.

After the measurement is made on the water meter tubes, the horizons corresponding to the tube reports are written out from the tables, and the horizon difference is calculated. If the slope is measured, this difference must be divided by the length of tube 67. If the flow velocity is determined, then this difference in height is inserted into the formula: v k} 2gh.

Tpo-lvografy «Red Pechatnik, Leningrad, Goach-Duichrodny, V5.

The coefficient (k) depends only on the shape of the tip of the tube 39 and is determined by the calibration of this tip.

In order to accurately determine the difference in height, it is necessary to accurately pre-compile the tables for translating the readings of gauge glasses to the height of the horizons in the chambers of the instrument. If there is another, already calibrated device, then the calibration is performed by comparing the readings of the instruments when the water level in the vessel changes.

SUBJECT OF THE PATENT.

1. An instrument for measuring the difference in water levels, flow rates and slopes, characterized by the use of chambers 8. 9, 10 and 77 enclosed in housings 20 and 13 connected by tubes 27 symmetrically arranged around a common axis, equipped with a common connecting tap 72 and connected in pairs with water tubes

6 and 7, in turn, connected to chambers 4 and 5, which are equipped with a distribution valve 3, whose processes are through flexible tubes

7 and 2 are connected to Pitot tubes 38 and 40, of which tube 40 is integral with an internal extension tube 39, which pitot tubes are enclosed in a tank 42 closed from the top with an upper part connected with tube 44, carrying a mercury gauge 48 on the side process, and a flexible tube 79, with a crane 18 connecting with each other through channel 31 - chambers 4 and 5, using channel 30 - casing 20 with tube 79 and, finally, through channel 32 - both ends 30 vi 31 between each other, and besides, the middle part of the tank 42 is connected by means of a process 47 and the flexible tube 14 reservoir 20.

2. With the device specified in clause 1, if it is used as a device for measuring inclines, instead of using a tube 39, use a long tube 67 held in a horizontal position with the help of a float 62.

t-.-f

j-ii

4u

: M iiViiR

 iiHim | and 17L) .1

 H - lit -i

1 I; Of). AI

5 D,

H.: - And

P lifi

50 r1- n:

 / 7

.J, N Y

/ W r i

 / h it

FIG.

50

4P 5Q