RU130734U1 - HYDRAULIC UNIVERSAL LABORATORY STAND - Google Patents

Abstract

1. A hydraulic universal laboratory bench made in the form of tanks, pumps, measuring instruments and test elements placed on a common frame, connected by a single system by pipelines, characterized in that pressure and and pressure gauges are mounted on a spatial frame providing visual and technical accessibility of the functional elements of the stand receiving tanks, pumps, as well as pressure and drain pipelines located vertically and common to eight sections of the stand, placed between them in a horizontal plane and designed to study the Bernoulli equation, modes of fluid motion, pressure losses along the length of the pipe, local pressure losses, the process of fluid outflow from holes and nozzles, methods and instruments for measuring fluid flow, water hammer in a pressure pipe, research of centrifugal pump operating modes, sequential and parallel operation of centrifugal pumps and cavitation in a centrifugal pump. 2. The stand according to claim 1, characterized in that it includes a section for studying the Bernoulli equation, which is a rectangular pipe located at an angle to the horizon, made of a transparent material, in the center of which there is a smooth narrowing and expansion, five sections are highlighted in the pipeline, one in the center of gravity of the pipe in a narrow section and two in the wide parts of the pipe before and after the narrowing is symmetrical to the center of gravity, in each section two devices are connected - the piezometer is connected by a flexible tube to the side wall of the pipeline at equal to the center of gravity of the living section of the flow, and the full pressure tube is inserted in the upper part of the pipe to the center of

Description

The invention relates to educational and laboratory equipment in the disciplines: hydraulics (fluid and gas mechanics); technical hydromechanics; hydrodynamics; hydroaeromechanics; hydraulics and aerodynamics; technical fluid mechanics; hydraulics and hydraulic machines; hydraulics and hydropneumatic automation; hydraulics, hydrology and hydrometry; hydraulics, water supply and sewerage; hydraulics, hydraulic machines and hydropneumatic drive; hydraulics and hydropneumatic systems; hydrodynamics and fundamentals of heat and mass transfer; basics of heat and mass transfer; processes and apparatuses, etc.

This device is intended for visual educational demonstration and identification of patterns in laboratory research:

- Bernoulli equations;

- modes of fluid movement;

- pressure losses along the length of the pipe;

- local pressure losses;

- fluid outflow through openings and nozzles;

- methods and instruments for measuring fluid flow;

- water hammer in the pressure pipe;

- operating modes of the centrifugal pump;

- sequential and parallel operation of centrifugal pumps;

- cavitation in a centrifugal pump.

The universal hydraulic bench ТМЖ-2 is known from the existing level of technology for studying hydrodynamic processes, which is made of one table having a horizontal mounting surface on which one of several interchangeable module devices is placed, for example, for determining hydraulic resistance, made of metal pipes, and on a vertical surface attached to the rear edge of the horizontal mounting surface there are several piezometers for visual observation pressure in various sections of round metal pipes interconnected in series. In addition, several float rotameters are attached to the vertical surface, which make it possible to measure the flow rate of the fluid flowing in the pipes supplied by a centrifugal pump placed above the horizontal surface [1].

Known educational equipment for universities - stand "Hydraulics - State Duma", adopted as a prototype. The stand is made of one table on a horizontal surface of which there is a device made of glass pipes of different diameters, which allows fluid to study their hydraulic resistance at different Reynolds numbers when moving along them, and several piezometers are located on a vertical surface attached to the edge of the horizontal surface for visual observation of pressure drops in various sections of round glass pipes interconnected in series [2].

The disadvantages of the above stands is that they are not equipped with elements that allow to study the phenomena of fluid flow from holes and nozzles, water hammer; methods and instruments for measuring fluid flow, operation parameters of one and two pumps connected in various ways, as well as the fact that some of the functional elements of the stands are hidden under their surfaces, which does not allow us to fully represent the entire technological process of the stand during the research process.

The objective of the invention is the unification in one universal laboratory stand of the main laboratory work on the course hydraulics (fluid and gas mechanics) and courses with the equivalent name, in order to reduce the number of basic elements that make up the stands for each laboratory work, to ensure multifunctionality and the multiplicity of their use and as a result, a decrease in the area occupied by laboratory equipment, the cost of equipment, increased visibility, ongoing laboratory work and visual and technical high availability of functional elements of the stand.

The problem is solved by the fact that on the spatial frame mounted pressure and intake tanks, pumps, as well as pressure and drain pipelines common to all sections of the stand. Between vertically located, pressure and drain pipelines are placed sections of the stand, which are, horizontally, at different levels, located pipelines on which the studied elements are mounted and connected to measuring instruments. Sections are separated from the pressure and drain pipelines by taps. In the pressure tank, during the operation of the stand, a constant level is maintained due to the continuous circulation of liquid, constantly pumped from the receiving tank to the pressure tank and overfilling it in the opposite direction. The movement of fluid from the pressure tank through the sections into the receiving tank occurs under the action of gravity at a constant pressure. Instruments for measuring the flow rate of liquids of various types are installed on a common drain pipe, providing flow measurement during all laboratory work.

Section I is a rectangular pipe located at an angle to the horizon, made of a transparent material, a smooth narrowing and expansion is made in the center of the pipe. Five sections are distinguished in the pipeline, one in the center of gravity of the pipe in a narrow section, and two in wide parts of the pipe before and after the narrowing is symmetrical to the center of gravity. Two devices are connected in each section - the piezometer is connected by a flexible tube to the side wall of the pipeline at the level of the center of gravity of the living section of the flow and the tube of full pressure is inserted in the upper part of the pipe to the center of gravity of the living section of the stream, bent and turned against the direction of flow. All instruments are displayed on a common piezometric shield. Section I is designed to study the Bernoulli equation.

Section II is a horizontally located, transparent tube, at the beginning of which, in the direction of the liquid, a thin tube is connected to the center of gravity of the living section connected by a flexible hose to the tank containing ink, the ink supply is regulated by a crane. At the end of the transparent pipe, a valve is installed that allows you to smoothly change the flow rate of the fluid flow and a rotameter that measures flow. Water temperature is controlled by a digital thermometer. Section II is designed to study the modes of fluid movement.

Section III is a horizontal pipeline to which two piezometers are connected at a certain distance from each other. At the end of the pipe, in the direction of the fluid, a tap is installed that allows you to change the fluid flow. Water temperature is controlled by a digital thermometer. Section III is designed to study the pressure loss along the length of the pipe.

Section IV is a pipeline on which various local resistances are made - a sharp turn of 90 °, a smooth turn of 90 °, a sharp expansion, a sharp narrowing, a smooth expansion, a smooth narrowing, ball valve, valve, gate valve. Before each local resistance and after, piezometers are connected to the pipeline, which are displayed on a common piezometric shield. Section IV is designed to study local pressure losses.

Section V includes a separate pressure tank, in which, during the operation of the stand, a constant level is maintained due to the continuous circulation of liquid constantly pumped from the receiving tank to the pressure tank and overfilling it in the opposite direction and three individual receiving measuring tanks, with a drain into the common receiving tank and the possibility of overlapping drain. In a pressure tank, at a certain distance from its bottom and walls, a hole is made in a thin wall and a cylindrical and conical converging nozzle is mounted. The nozzles and the hole are positioned so that the axis of their outlet openings coincides with the longitudinal axial line of the receiving measuring tanks. Section V is designed to study the flow of fluid from holes and nozzles.

Section VI is a common drain pipe on which, at a certain distance from each other, various types of flow measuring instruments are mounted that correspond to different flow measurement methods. Section VI is designed to study methods and instruments for measuring fluid flow.

Section VII is a long pipeline into which liquid is supplied from a receiving tank by a centrifugal pump and drained through a common drain pipe and flow meters installed on it. At the end of a long pipeline, in the place where it joins the drain, a normally open solenoid valve is installed on the pipeline, which closes when the button closes the power contacts of the valve winding. A pressure sensor is installed in front of the valve with a memory of the maximum and minimum pressure in the pipeline. Section VII is designed to study water hammer in a pressure pipe.

Section VIII is a piping system in which two centrifugal pumps and a crane system are installed, allowing pumps to be connected in series, in parallel or to examine one pump. The suction pipe of each pump is connected to the receiving tank and is equipped with an overpressure and vacuum sensor, pressure pipes are connected to a common drain pipe and a flow meter installed on it. An overpressure sensor is connected to a common pressure pipe and a valve is installed to control the pump flow. The pumps are connected to the mains via a digital wattmeter. Section VIII is designed to study the operation of a centrifugal pump, the sequential and parallel operation of centrifugal pumps and cavitation in a centrifugal pump.

The novelty of the proposed technical solution is that, in order to reduce the number of basic elements that make up the stands for each laboratory work, to ensure multifunctionality and their repeated use, and as a result, reduce the area occupied by laboratory equipment, the cost of equipment, and increase the visibility, ongoing laboratory work and visual and technical accessibility of the functional elements of the stand in one universal laboratory stand combined the main laboratory ive works on the course hydraulics (fluid and gas mechanics) and courses with an equivalent name. This is achieved by the fact that pressure and intake tanks, pumps, as well as pressure and drain pipelines common to all sections of the stand are mounted on the spatial frame. Between vertically located, pressure and drain pipelines are placed sections of the stand, which are, horizontally, at different levels, located pipelines on which the studied elements are mounted and connected to measuring instruments. Sections are separated from the pressure and drain pipelines by taps. In the pressure tank, during the operation of the stand, a constant level is maintained due to the continuous circulation of liquid, constantly pumped from the receiving tank to the pressure tank and overfilling it in the opposite direction. The movement of fluid from the pressure tank through the sections into the receiving tank occurs under the action of gravity at a constant pressure. Instruments for measuring the flow rate of liquids of various types are installed on a common drain pipe, providing flow measurement during all laboratory work.

The invention is illustrated by drawings, where figure 1 shows a training laboratory stand, front view; figure 2 - educational laboratory stand, rear view; figure 3 - training laboratory stand, top view.

The universal hydraulic laboratory bench consists of a spatial frame 1, on which pressure head 2, 3 and receiving tanks 4, pumps 5, 6, as well as pressure head 7 and drain 8 are mounted pipelines common to all sections of the stand. Between vertically located, pressure 7 and drain 8 pipelines are placed sections of the stand, which are horizontally located at different levels pipelines on which the elements under study are mounted and measuring instruments are connected. Sections are separated from the pressure 7 and drain 8 pipelines by taps. In the pressure tank 2, during the operation of the stand, a constant level is maintained due to the continuous circulation of the liquid constantly pumped by the pump 5 from the receiving tank 4 to the pressure tank 2 and overflowing it in the opposite direction. The movement of fluid from the pressure tank 2 through the sections into the receiving tank 4 occurs under the action of gravity at a constant pressure. On a common drain pipe 9, instruments for measuring the flow rate of liquids of various types are installed, providing flow measurement during all laboratory work.

Section I is a rectangular pipe 10 located at an angle to the horizon, made of a transparent material, a smooth narrowing and expansion is made in the center of the pipe. Five sections are distinguished in the pipeline, one in the center of gravity of the pipe in a narrow section, and two in wide parts of the pipe before and after the narrowing is symmetrical to the center of gravity. Two devices are connected in each section - the piezometer is connected by a flexible tube to the side wall of the pipeline at the level of the center of gravity of the living section of the flow and the tube of full pressure is inserted in the upper part of the pipe to the center of gravity of the living section of the stream, bent and turned against the direction of flow. All instruments are displayed on a common piezometric shield 11.

Section II is a horizontally located, transparent tube 12, at the beginning of which, in the direction of the liquid, a thin tube 13 is connected to the center of gravity of the living section, connected by a flexible hose 14 to the ink tank 15, the ink supply is regulated by a tap 16, at the end of the transparent tube a valve 17 is installed that allows you to smoothly change the flow rate of the fluid flow and a flow meter 18, which measures the flow rate, the water temperature is controlled by a digital thermometer 19.

Section III is a horizontal pipeline 20 to which two piezometers are connected at a certain distance from each other. At the end of the pipe, in the direction of the fluid, a valve 21 is installed, which allows you to change the fluid flow. Water temperature is controlled by a digital thermometer 19.

Section IV is a pipeline 22, on which various local resistances are made - a sharp turn of 90 °, a smooth turn of 90 °, a sharp expansion, a sharp narrowing, a smooth expansion, a smooth narrowing, ball valve, valve, gate valve. Before each local resistance and after, piezometers are connected to the pipeline, which are displayed on a common piezometric shield 23.

Section V includes a separate pressure tank 3, in which, during the operation of the stand, a constant level is maintained due to the continuous circulation of the liquid constantly pumped by the pump 5 from the receiving tank 4 to the pressure 3 and overflowing it in the opposite direction and three individual receiving measuring tanks 24, with drain into a common receiving tank 4 and the possibility of overlapping drain. In the pressure tank 3, at a certain distance from its bottom and walls, a hole is made in a thin wall and a cylindrical and conical converging nozzle is mounted. The nozzles and the hole are arranged so that the axis of their outlet openings coincides with the longitudinal axial line of the receiving measuring tanks 24.

Section VI is a common drain pipe 9 on which, at a certain distance from each other, various types of flow measuring instruments are mounted, corresponding to different flow measurement methods.

Section VII is a long pipeline 25, into which liquid is supplied from a receiving tank 4 by a centrifugal pump 5 and drained through a common drain pipe 9 and flowmeters mounted on it. At the end of a long pipeline, in the place where it joins the drain, a normally open solenoid valve 26 is installed on the pipeline, which closes when the button 27 is closed, which closes the power contacts of the valve winding. A pressure sensor 28 is installed in front of the valve with a memory of the maximum and minimum pressure in the pipeline.

Section VIII is a piping system in which two centrifugal pumps 5, 6 and a crane system are installed, which allows you to connect the pumps in series, in parallel or to examine the operation of one pump. The suction pipe 29 of each pump is connected to a receiving tank 4 and is equipped with an overpressure and vacuum sensor 30, the pressure pipes 31 are connected to a common drain pipe 9 and a flow meter 32 mounted thereon, an overpressure sensor 33 is connected to a common pressure pipe and a valve 34 is installed. Pumps 5, 6 are connected to the electric network through a digital power meter 35.

Before operation, the receiving tank 4 is filled with liquid, the pump 5 pumps the working fluid from the receiving tank 4 through the piping system to the pressure tank 2, when filling, the liquid is drained through the overflow piping 36 to the receiving tank 4, thus, a constant pressure is maintained in the pressure tank 2 . When using section I to perform laboratory work, the taps separating section I from the pressure 7 and drain 8 pipelines are opened, the liquid from the pressure tank 2 under the influence of gravity passes through pipe 10, the drain pipe 8 and drains through a common drain pipe 9, passing through flowmeters into the receiving tank 4. When the liquid passes through the selected sections of the pipeline 10, the devices installed in the sections record the piezometric and total pressure head of the liquid flow. When using section II, open the taps separating section II from the pressure 7 and drain 8 pipelines, the liquid from the pressure tank 2 under the action of gravity passes through a transparent pipe 12, valve 17, a flow meter 18, drain pipe 8 and through a common drain pipe 9 into the receiving tank 4. Ink is supplied through the tube 14 from the ink tank 15 and the faucet 16 to the transparent pipe 12, the presence of which in the stream allows to determine the liquid flow mode, while adjusting the flow rate of the liquid by the valve 17 in the transparent pipe 12, you can set ny modes of fluid motion. When using section III, open the taps separating section III from the pressure 7 and drain 8 pipelines, the liquid from the pressure tank 2 under the action of gravity passes through the pipe 20, drain pipe 8 and the common drain pipe 9 into the receiving tank 4. When the fluid moves through the pipe 20 piezometers installed at the beginning and at the end of the pipeline fix the piezometric heads, flowmeters installed on a common drain pipe 9, the flow rate and temperature of the liquid is determined using a temperature sensor 19 s, which allows to determine the pressure loss along the length empirically and theoretically calculated. When using section IV, open the taps separating section IV from the pressure 7 and drain 8 pipelines, the liquid from the pressure tank 2 under the action of gravity passes through the pipe 22 and, accordingly, through various local resistances, the drain pipe 8 and the common drain pipe 9 into the receiving tank 4. When the fluid moves, the piezometers installed before and after each local resistance fix the piezometric head, flow meters installed on a common drain pipe 9 fix the flow rate of the liquid, which poses olyaet estimate the local loss in each local resistor and compared with the calculated values. When using section V, the pump 5 pumps the working fluid from the receiving tank 4 through the piping system into the pressure tank 3, when filling it, the liquid is drained through the overflow piping 36 back to the receiving tank 4, thus, a constant pressure is maintained in the pressure tank 3. At the same time, through a hole in the thin wall and a cylindrical and conical converging nozzle attached to the tank, the liquid flows into the receiving measuring tanks 24, from which the liquid is drained back to the receiving tank 4. When the liquid flows out, the parameters of the flow process are fixed, which allows to determine the compression rate and velocity empirically and compare them with tabular. When using section VI, the pump 5 pumps the working fluid from the receiving tank 4 through the piping system into a common drain pipe 9 and through the various types of flow meters installed on it back into the receiving tank 4. Determining the flow rate by various types of flow meters allows us to study their operating principle and evaluate the degree of accuracy of different flow measurement methods. When using section VII, the pump 5 pumps the working fluid from the receiving tank 4 through a long pipe 25, a pressure sensor 28, a normally open solenoid valve 26 into the common drain pipe 9 and through the various types of flow meters installed on it back into the receiving tank 4. When the liquid moves by pressing buttons 27, voltage is applied to the coil of the electromagnetic valve 26, as a result, the valve closes and a hydraulic shock occurs in the pipe 25, the pressure increase during a hydraulic shock is detected by the pressure sensor 28 with the memory of the maximum and minimum pressure in the pipeline, the liquid flow rate is determined by flow meters installed on a common drain pipe 9. The fixation of pressure in the pressure pipe allows one to determine the experimental increase in pressure during water hammer and compare it with the calculated value. When using section VIII, the liquid from the receiving tank 4, through the suction pipe 29, with an overpressure and vacuum sensor 30 installed on it, is pumped into the pressure pipe 31 with the overpressure sensor 33 installed on it, then into a common drain pipe 9, through the flow meter 32 and the crane 34 back to the receiving tank 4. Changing the flow rate using the valve 34 and fixing the pump operation parameters in various modes, allows to obtain the characteristic of a centrifugal pump and its cavitation characteristic. To test two centrifugal pumps 5 and 6, connected in parallel and sequentially using a network of pipelines and a crane system, the pumps are first connected in series with the subsequent fixing of the pump parameters in different operating modes, then in parallel with the subsequent fixing of the pump parameters in different operating modes. Information sources:

1.http: //www.rosuchpribor.ru/russian/prof/mehzhidk/tmg2.html

2.http: //www.rosuchpribor.ru/russian/prof/mehzhidk/gidrodin.html

Claims (9)

1. A hydraulic universal laboratory bench made in the form of tanks, pumps, measuring instruments and test elements placed on a common frame, connected by a single system by pipelines, characterized in that pressure and and pressure gauges are mounted on a spatial frame providing visual and technical accessibility of the functional elements of the stand receiving tanks, pumps, as well as pressure and drain pipelines located vertically and common to eight sections of the stand, placed between them in a horizontal plane and designed to study the Bernoulli equation, modes of fluid motion, pressure losses along the length of the pipe, local pressure losses, the process of fluid outflow from holes and nozzles, methods and instruments for measuring fluid flow, water hammer in a pressure pipe, a study of the operation modes of a centrifugal pump, sequential and parallel operation of centrifugal pumps and cavitation in a centrifugal pump. 2. The stand according to claim 1, characterized in that it includes a section for studying the Bernoulli equation, which is a rectangular pipe located at an angle to the horizon, made of a transparent material, in the center of which there is a smooth narrowing and expansion, five sections are highlighted in the pipeline, one in the center of gravity of the pipe in a narrow section and two in the wide parts of the pipe before and after narrowing symmetrically to the center of gravity, in each section two devices are connected - the piezometer is connected by a flexible tube to the side wall of the pipeline on level of the center of gravity of the living section of the flow, and the tube of full pressure is introduced in the upper part of the pipe to the center of gravity of the living section of the stream, bent and turned against the direction of flow, with all instruments displayed on a common piezometric shield. 3. The stand according to claim 1, characterized in that it includes a section for studying the modes of fluid movement, which is a horizontally located, transparent pipe, at the beginning of which, in the direction of gravity of the live section, a tube connected to the tank with a flexible hose is inserted containing ink, the ink supply is regulated by a tap, at the end of the transparent pipe there is a valve that allows you to smoothly change the flow rate of the liquid, and a flow meter that measures the flow, and at the beginning of the pipe there is a digital thermometer to control the water temperature. 4. The stand according to claim 1, characterized in that it includes a section for studying pressure losses along the length of the pipe, including a horizontal pipeline, to which two piezometers are connected at the beginning and at the end, and a valve is installed at the end of the pipe, allowing change fluid flow. 5. The stand according to claim 1, characterized in that it includes a section for studying local pressure losses, which includes the pipeline, with various local resistances made on it - a sharp turn of 90 °, a smooth turn of 90 °, a sharp expansion, a sharp narrowing , smooth expansion, smooth narrowing, ball valve, valve, gate valve, piezometers connected to a common piezometric shield are connected to the pipeline before each local resistance and after. 6. The stand according to claim 1, characterized in that it includes a section for studying the process of fluid outflow from the openings and nozzles, including a separate pressure tank, in which, during operation of the stand, a constant level is maintained due to the continuous circulation of liquid constantly pumped from the receiving tank by the pump into the pressure head, and overflowing it in the opposite direction, and three individual receiving measuring tanks with a drain into a common receiving tank and the possibility of blocking the drain, a hole is made in the wall of the pressure tank and cylindrical mounted Single and tapered converging nozzle arranged such that the axes of their outlet openings coincide with the longitudinal centerline of receiving dimensional tanks. 7. The stand according to claim 1, characterized in that it includes a section for the study of methods and devices for measuring fluid flow, which is a common drain pipe, on which various types of flow measuring instruments are mounted, corresponding to different flow measurement methods. 8. The stand according to claim 1, characterized in that it includes a section for studying hydraulic shock in a pressure pipe, including a pipe into which liquid is supplied from a receiving tank by a centrifugal pump and drained through a common drain pipe and flow meters installed on it, at the end of the pipe normally open solenoid valve that closes when a button is pressed that closes the power supply contacts of the valve winding; a pressure sensor with a maximum and minimum pressure memory is installed in front of the valve Gadfly. 9. The stand according to claim 1, characterized in that it includes a section for studying the operating modes of a centrifugal pump, sequential and parallel operation of centrifugal pumps and cavitation in a centrifugal pump, which is a piping system in which two centrifugal pumps and a crane system are installed, allowing to connect pumps in series, in parallel or examine one pump, the suction pipe of each pump is connected to a receiving tank and is equipped with an overpressure and vacuum sensor, pressure pipes connected to a common drain pipe and a flow meter installed on it, an overpressure sensor and a valve are connected to the common pressure pipe, the pumps are connected to the electrical network through a digital wattmeter.

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