RU2375681C1 - Flowmetre for fluids in open basins - Google Patents

Abstract

FIELD: instrumentation.

SUBSTANCE: invention is intended for measuring volume-flow rate of fluid in channels, nonpressurised pipelines of large diametre and outflow channels. Level measuring unit 1 and fluid average flow velocity unit 4 are mounted on carriage 9 of remote control gear controlling flowmeter position along basin width. The control gear is mounted being able to travel along rod 10. Unit 1 is executed in the form of three-dimensional four-link parallelogram mechanism, float 2 and sensitive element 3 in the form of linear rheochord. Unit 4 contains vertical and horizontal blades 5 in the cross-point of which sensitive elements 6 are placed. The sensitive elements are membranes associated with resistive strain-gauges. Blade 5 is mounted in hollow bushing 51 of parallelogram mechanism in the lower part of which float 2 is placed. Sensitive elements are connected with electronic unit for receive and processing electric signals.

EFFECT: invention improves accuracy of measurements and reduces their labor content.

9 cl, 7 dwg

Description

The invention relates to measuring equipment for flow meters, and in particular to devices for measuring the volumetric flow rate of liquid media in open reservoirs - channels, non-pressure pipelines of large cross-section and waste trays.

Known ultrasonic flowmeter RVU - 1, including ultrasonic sensors, stepper motors, communication cable, cables for the mechanism of movement of stepper motors, fastening the cables on the berm of the reservoir, the secondary unit (see article M.A. Varichev. Technical justification and research results of the ultrasonic flow meter RVU - 1. - Ways to improve the efficiency of irrigated agriculture: collection of articles of the Federal State Institution of Science and Technology "RosNIIPM" / Edited by V.N.Shedrin. - Novocherkassk: LLC "Helikon", 2007. - Issue 38. - 198. - P.131- 134. A copy of the article is attached).

The disadvantages of the described RVU-1 flowmeter, despite the declared measurement error of 5%, include low measurement accuracy and high labor and time costs.

The closest analogue to the claimed object includes a liquid flow meter in open water, comprising a liquid level measuring unit and an average liquid flow velocity measuring unit, as well as an electronic signal receiving and processing unit, in which the liquid measuring unit is made in the form of a rotary lever with a spherical float immersed in the liquid to a depth less than the radius of the sphere, and the sensitive element for measuring the angle of vertical movement of the float is made on the basis of the ADXL chip and fixed it is mounted on the lever, while the unit for measuring the flow rate of the liquid is made in the form of a rotary blade, the end of which is paired with the axis of vertical rotation, and the other end is freely immersed in the liquid, in turn, the sensitive element for measuring the angle of rotation of the blade is made on the basis of a second similar type microcircuit ADXL series and fixed to the blade (RU, patent No. 2251080. C1. IPC ⁷ G01F 1/00. Flowmeter of liquid media in open reservoirs. / S.N. Zimin, V.N. Kozhin, A.F. Pisarev, N. V.Tingaev, V.V. Trofimov (RU). - Application No. 2003123875/28; Claimed July 30, 2003; Publ. 04/27/2005, Bull. No. 12).

The disadvantages of the described liquid flow meter in open reservoirs include the low accuracy of measuring the flow rate of water in the channels, associated with both a large error in measuring the depth of the reservoir and the rate of fluid outflow.

The essence of the claimed invention is as follows.

The problem to which the claimed invention is directed is to obtain reliable information about the performance of reservoir channels, non-pressure pipelines of large cross-section and waste trays.

EFFECT: increased accuracy of measurements and reduction of labor costs and time for setting up and performing experiments.

The specified technical result is achieved by the fact that in the known flowmeter of liquid media in open reservoirs containing a unit for measuring the liquid level in the form of a rotary lever, a float and a sensing element for recording the position of the float, a unit for measuring the average fluid velocity in the form of a blade immersed in a liquid with a sensing element and an electronic unit for receiving and processing signals of sensing elements, according to the invention, it is equipped with a mechanism for remote control of the flow meter position a water body made in the form of a carriage mounted to move by means of an appropriate mechanism along the rod, the ends of which are fixed in racks installed on the berm of an open water body, the liquid level measuring unit and the average flow rate measuring unit are mounted on the carriage, while the liquid level measuring unit made in the form of a volumetric four-link parallelogram mechanism with a base link formed by parallel stiffeners on the carriage plate, the front ends of which are mounted ovans on the axes located in the holes of the indicated stiffeners, as well as two pairs of rods, a hollow sleeve with trunnions at the rear ends of the rods, a float located at the bottom of the hollow sleeve, and a sensing element in the form of a linear rechord mounted diagonally on the parallelogram mechanism, block measuring the average fluid flow rate contains vertical and horizontal blades, at the point of intersection of which and with equal distance from it along the blades are sensitive elements made in the form of a membrane with ü membranes of at least 100 mm ² , coupled with strain gauge sensors, the blade of the unit for measuring the average fluid flow rate is mounted in the hollow sleeve of the parallelogram mechanism; the rod of the welded structure is made in the form of a pair of profiles of either round, or square, or rectangular sections and jumpers in the form of plates between them; each rack is equipped with a pair of bushings with collet grips for fixing the end of the rod and an axle with a threaded shank in the upper part of the rack; the carriage moving mechanism along the rod is made in the form of two pulleys placed with the possibility of free rotation on the trunnion pins of the racks, and a rope, the ends of which are placed on the carriage by means of tension, and the pulley branches are repeatedly covered by the rope; at least one pulley has a handle for rotating the pulley on the rack axle; each rope tension means is made in the form of a threaded sleeve, a hollow bolt installed in it with a conical cavity in the head and a truncated cone at the end of the rope, while the threaded sleeve is mounted on the stiffener of the carriage; the carriage is formed by a plate with stiffening ribs on one side and support rollers on the other side, mounted with coverage of the surface of the rods; the float, either in the form of a hollow torus or in the form of a hollow washer, is mounted coaxially to the hollow sleeve of the four-link parallelogram mechanism by means of a threaded sleeve and a lock nut on the threaded section of the said sleeve; the blade of the unit for measuring the average fluid flow rate is mounted in the hollow sleeve of the parallelogram mechanism by means of a rod and is fixed with a quick-release finger.

The invention is illustrated by drawings.

Figure 1 shows a flow meter of liquid media in open reservoirs, a plan view.

In Fig.2 is a section aa in Fig.1, a longitudinally vertical section of a flowmeter of liquid media in open reservoirs.

Figure 3 is a section bB in figure 1, a transverse vertical section of a unit for measuring the average fluid flow rate.

Figure 4 is a section bb in figure 1, a transverse vertical section of the left rack of the remote control mechanism for the position of the flow meter across the width of the reservoir.

In Fig.5 is a section GG in Fig.1, a longitudinally vertical section of the carriage and the rod of the remote control mechanism.

In Fig.6 is a section DD in Fig.3, a longitudinally-vertical section of a sensing element for recording the average fluid flow rate.

In Fig.7 is a cross-section EE in Fig.1, a transverse vertical section of the means of tensioning the ends of the branches of the rope of the mechanism for remote control of the position of the flow meter.

Information confirming the possibility of implementing the claimed invention are as follows.

The liquid flow meter in open reservoirs (see FIGS. 1 and 2) contains a liquid level measuring unit 1 in the form of a rotary lever, a float 2, a sensing element 3 for recording the position of the float 2 relative to the bottom of the reservoir, and a unit 4 for measuring the average liquid flow rate in in the form of a blade 5 immersed in a liquid with a sensing element 6 and an electronic unit for receiving and processing electrical signals of the sensing elements.

The liquid flow meter in open reservoirs (see FIGS. 1, 2, 4, 5 and 7) is equipped with a mechanism 7 for remote control of the flow meter position along the width of the reservoir 8. The mechanism 7 for remote control of the flow meter position in the form of blocks 1 and 4 is made in the form of a carriage 9 (figure 1, 2 and 5), the rod 10, the racks 11 and 12, the mechanism 13 for moving the carriage 9 along the rod 10.

The carriage 9 is mounted for movement by means of a suitable mechanism along the rod 10. The rod 10 of the welded structure is placed on the posts 11 and 12 with the possibility of dismantling and fixing in the working position. Racks 11 and 12 are installed vertically on the berm 14 and 15 of the open reservoir 8 (see figures 1 and 2).

A block 1 for measuring the liquid level and a block 4 for measuring the velocity of the fluid flow are mounted on the carriage 9 with the possibility of dismantling. The carriage 9 is formed by a plate 16 with stiffening ribs 17 on one side and on the other side by support rollers 18. The support rollers 18 are arranged in pairs with coverage of the upper and lower surfaces of the rod 10.

The rod 10 (see figure 1, 2 and 5) is made in the form of a pair of profiles or round, or square, or rectangular sections and jumpers 19 in the form of plates between them. The rod 10 is a basic element, and its design has high requirements for material consumption, flatness, parallelism of the position of the profiles and the geometric shape of the section.

Each rack 11 (12) (FIGS. 2 and 4) in the form of a hollow pipe is equipped with a pair of bushings 20 and 21 for fixing the free ends 24 and 25 of the rod 10. At the upper end of the rack 11 (12), a pin 26 with a threaded shank 27 is mounted in the upper parts. Axle and radial channels are made in pin 26 for supplying grease through a grease nipple 28.

The mechanism 13 for moving the carriage 9 along the rod 10 (see FIGS. 1, 2, 4, 5 and 7) is made in the form of two pulleys 29 and 30 connected by a rope 31 to the carriage 9. The pulleys 29 and 30 are placed with the possibility of free rotation on the pins 26 racks 11 and 12. In the hub of each pulley 29 (30), a sliding bearing 32 is pressed in (Fig. 4). The branches of the rope 31 repeatedly cover the pulleys 29 and 30. The ends 33 and 34 of the rope 31 by means of tension are placed on the carriage 9 (Fig.7).

To control the position of the carriage 9 on the rod 10, at least one pulley 29 has a handle 35 for rotating the pulley 29, and through the rope 31 and the pulley 30 placed on the trunnions 26 of the racks 11 and 12.

Each means of tensioning the rope 31 (see Fig.7) is made in the form of a threaded sleeve 36. The sleeve 36 is welded to the inclined rib 37 stiffness (see Fig.5, 7 and 2). In the threaded sleeve 36, a hollow bolt 38 is installed with a conical cavity 39 in the head 40. In the conical cavity 39 of the bolt 38, the end 34 of the rope 31 with a truncated cone 41 is installed. The truncated cone 41 is mounted on the end 31 of the rope and is fixed either by soldering or crimping or by gluing to form an integral connection. The axial displacement of the pulleys 29, 30 on the trunnions 26 of the uprights 11 and 12 are limited by washers 42 and fastening means 43 (Fig. 4).

Each support roller 18 is given a surface shape of the rod profiles 10. The support roller 18 is mounted on an axis 45 through a rolling bearing 44 and a bearing 44 is mounted on the plate 16 of the carriage 9 of the mechanism 7 using the fastening means 46 and the distance sleeve 47. The described carriage design 9 provides its movement along the rod 10. Placed on the mechanism 7 for remote control of the position of the flowmeter along the width of the reservoir 8, the unit 1 for measuring the liquid level is made in the form of a three-dimensional parallelogram Wow mechanism (see figure 1, 2, 3 and 5). The base link of the specified mechanism is formed by parallel stiffening ribs 17 on the plate 16 of the carriage 9. Axles 48 are placed in the holes of the stiffening ribs 17. On the axles 48, the front ends of two pairs of rods 49 are placed through the spacer sleeve and the hinge of the sensing element 3. The rear ends of the rods 49 by means of pins 50 mounted on the hollow sleeve 51. The float 2 is located in the lower part of the hollow sleeve 51.

The float 2 (see FIGS. 2 and 3), either in the form of a hollow torus or in the form of a hollow flat washer, is mounted coaxially with the hollow sleeve 51 of the four-link parallelogram mechanism by means of a threaded sleeve 52 and a lock nut 53 on the threaded portion of the said sleeve 51.

The sensitive element 3 (see figures 1 and 2) in the form of a linear rechord is installed along the diagonal of the four-link parallelogram mechanism. One of the hinges of the element 3 is mounted on the axis 48 of the carriage 9, and the other hinge is mounted on the lower pin 50 of the hollow sleeve 51 (see figure 3).

Block 4 measuring the average fluid flow rate contains vertical and horizontal blades 5 (figure 3). Sensitive elements 6 are placed at the point of intersection of the blades 5 and with equal distance from it along the vertical and horizontal blades 5.

The frontal part of each blade 5 is given a pointed shape with a cutting edge 54 for separating fluid flows (Fig.6). The vertical blade 5 of the unit 4 for measuring the average liquid flow rate by means of the rod 55 is mounted in the hollow sleeve 51 (Fig. 3) of the parallelogram mechanism and is fixed with a quick-release finger 56. On the rod 56, a group of holes are made for the diameter of the finger 56 to change the position of the block 4 relative to the float 2.

Between the parts of the blades 5, welds are fixed to the sleeve 57 with conical inner surfaces (Fig.6). In the sleeve 57, a housing 58 of the sensing element 6 of the unit 4 for measuring the fluid flow rate is installed. Case 58 is shaped like a hollow truncated cone. The large base of the cone housing 58 is facing against the movement of the fluid flow. On the thickened part of the large base of the cone, an annular groove 59 is made on the front part to accommodate the sealing ring 60. On the cylindrical part of the thickening of the housing 58, a small thread 61 is made to accommodate the cover 62 in the form of a ring. A groove 63 is made in the cover 62 for installing the sealing ring 64. The diameters of the sealing rings 60 and 64 are made identical. A membrane 65 is installed between the rings 60 and 64. The membrane 65 can be made of either a thin carbon metal sheet, high-pressure polyethylene or plastics. The working surface of the membrane 65 is made with an area of 100 mm ² to simplify all calculations and calibration of the sensing element 6. A threaded cap 62 membrane 65 is fixed between the rings 60 and 64 on the front of the housing 58.

On the small base of the cone in the cavity of the housing 58, an o-ring 67 is placed in the annular groove 66 to prevent liquid from entering the cavity of the housing 58. On the cylindrical part 68 of the housing 58, a thread is made for screwing a shaped nut 69. With a shaped nut 69, the housing 58 is fixed in the sleeve 57 between the blades 5.

In the cylindrical part 68 of the housing 58, stepped coaxial cylindrical openings are made for receiving the sensing element 6 and the nut 70 for fixing it on the threaded shank 71.

The sensitive element 6 is made in the form of a rod of hardened carbon steel. The rounded portion 72 of the rod of the element 6 is coupled to the membrane 65. On the thinned portion 73 of the rod are glued strain gauge resistance sensors 74. The conductive ends of the sensors 74 are passed through radial and axial channels 75 in the rod of the sensing element 6.

The electronic unit for receiving and processing electrical signals includes a unit for amplifying electrical signals with nine sensitive sensors 6, a unit for recording ten electrical signals from sensitive sensors 6 and 3, and a timer every 0.01 s and 0.1 s, a power supply voltage of 6 and 9 B, a processor for processing digital data to obtain average values, measurement errors, accuracy, confidence interval, culling random values.

The flow meter of liquid media in open reservoirs operates as follows.

With a slight distance from the berms 14 and 15 of the reservoir 8, racks 11 and 12 are installed. The rod 10 is set in level. The ends 24 and 25 of the rod profiles 10 with collet grips 22 are fixed in the bushings 20 and 21 on the posts 11 and 12. The branches of the rope 31 are wound on the pulleys 29 and 30. The ends 33 and 34 of the rope 31 are installed together with the bolts 38 into the threaded sleeves 36. Unscrewing the bolts 38 from the threaded bushings 36, the branches of the rope 31 are tensioned. By rotating the pulley 30 by means of the handle 35 of the mechanism 15, the movement of the carriage 9 of the mechanism 7 along the rod 10 is checked.

Next, the float 2 is lowered to the surface of the reservoir 8. Due to the longitudinal rods 49 of the three-dimensional four-link parallelogram mechanism, the unit 1 for measuring the liquid level comes into operation. The sensing element 3 in the form of a linear rechord, mounted diagonally in a parallelogram, directly proportionally changes the magnitude of the vertical movement of the float 2 with respect to the bottom of the reservoir 8.

The capacity of the reservoir 8 is determined by the calculation according to the formula

where F _K is the cross section of the channel, m ² ;

V is the average fluid flow rate, m / s.

The cross-sectional area of the channel is determined as follows:

where b _cp is the average width of the reservoir, m;

H _b - water level in the channel, m.

The water level in the channel is determined by the calculation according to the formula:

where H is the height of the upper axis 48 from the bottom of the reservoir, m;

H ₁ - mark placement of the float 2 from the upper axis 48 of the four-link parallelogram mechanism, m

Thus, the sensitive element 3 determines the value of the mark H ₁ :

where k ₁ is the coefficient of proportionality;

h is the deviation mark of the oscilloscope beam on the oscillogram, fixing the position of the float 2 on the surface of the reservoir 8.

The average flow rate of a fluid in a pond is determined by the formula:

where k ₂ is the coefficient of proportionality;

P _cf - the average pressure force of the membrane 65 on the sensing element 6.

Before starting the research, the sensitive elements 6 are subjected to static and dynamic calibration. Electrical signals from the sensitive elements 3 and 6 were processed on a computer according to the corresponding program.

Thus, the claimed flowmeter ensures the achievement of the above technical result.

Claims (9)

1. A liquid flow meter in open water containing a unit for measuring the liquid level in the form of a rotary lever, a sensing element for recording the position of the float, a unit for measuring the average velocity of the liquid flow in the form of a blade immersed in the liquid with a sensing element, and an electronic unit for receiving and processing signals of the sensing elements , characterized in that it is equipped with a mechanism for remote control of the position of the flowmeter across the width of the reservoir, made in the form of a carriage mounted with the ability to change by means of the corresponding mechanism along the rod, the ends of which are fixed in the racks installed on the berms of the open reservoir, the liquid level measuring unit and the average flow rate measuring unit are mounted on the carriage, while the liquid level measuring unit is made in the form of a three-section parallelogram mechanism with parallel ribs formed stiffness on the carriage plate with a base link, two pairs of rods, the front ends of which are mounted on the axes located in the holes of the indicated ribs depth, as well as a hollow sleeve with trunnions at the rear ends of the rods, a float located at the bottom of the hollow sleeve, and a sensing element in the form of a linear rechord mounted diagonally on the parallelogram mechanism, the unit for measuring the average fluid flow rate contains vertical and horizontal blades, at intersections and the distance from it along the blades, are arranged sensing elements made in the form of membranes with a membrane area of at least 100 mm ^2, strain sensors associated with, the blade unit measuring the average flow rate of fluid is mounted in a parallelogram mechanism a hollow sleeve. 2. The flow meter according to claim 1, characterized in that the rod of the welded structure is made in the form of a pair of profiles, either round, or square, or rectangular section and jumpers in the form of plates between them. 3. The flow meter according to claim 1, characterized in that each rack is equipped with a pair of bushings with collet grips for fixing the end of the rod and an axle with a threaded shank in the upper part of the rack. 4. The flow meter according to claim 1, characterized in that the mechanism for moving the carriage along the rod is made in the form of two pulleys placed with the possibility of free rotation on the trunnion of the racks, and a rope, the ends of which are placed on the carriage by means of tension, and the pulley branches repeatedly cover the pulleys . 5. The flow meter according to claim 4, characterized in that at least one pulley has a handle for rotating the pulley on the rack pin. 6. The flow meter according to claim 4, characterized in that each rope tensioning device is made in the form of a threaded sleeve, a hollow bolt installed in it with a conical cavity in the head and a truncated cone at the end of the rope, while the threaded sleeve is mounted on the stiffener of the carriage. 7. The flow meter according to claim 1, characterized in that the carriage is formed by a plate with stiffeners on one side and support rollers on the other side, installed with coverage of the surface of the rod. 8. The flow meter according to claim 1, characterized in that the float either in the form of a hollow torus or in the form of a hollow washer is mounted coaxially with the hollow sleeve of the four-link parallelogram mechanism by means of a threaded sleeve and a lock nut on the threaded section of the said sleeve. 9. The flow meter according to claim 1, characterized in that the blade of the measuring unit of the average fluid flow rate is mounted in the hollow sleeve of the parallelogram mechanism by means of a rod and is fixed with a quick-release finger.

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