RU214994U1 - Impeller for testing protective coatings for cavitation resistance - Google Patents

Abstract

The utility model relates to the field of coating testing, namely to cavitation testing of special coatings designed to protect the flow parts of hydraulic machines from cavitation, and can be used to test protective coatings of hydraulic turbines. The technical result of the claimed utility model is to reduce the complexity of testing protective coatings for cavitation resistance, by reducing the time of testing in conditions close to real, without the use of specialized equipment. 1 fig.

Description

Technical field

The utility model relates to the field of coating testing, namely to cavitation testing of special coatings designed to protect the flow parts of hydraulic machines from cavitation, and can be used to test protective coatings of hydraulic turbines.

State of the art

A cavitation generator is known (SU 237817 dated 20.02.1967, IPC V06V 1/16, B01F 3/08), containing a cone-shaped rotor and stator, characterized in that, in order to increase its efficiency, the working surfaces of the rotor and stator are made rough, for example micro-toothed.

An ultrasonic device for studying the cavitation resistance of materials is known (SU 301187 dated 10/23/1967, IPC B06V 3/04), containing a magnetostrictive vibrator with an ultrasound concentrator, in the nodal plane of which a sample holder and a hermetically sealed chamber are fixed, characterized in that, in order to carry out tests in liquefied gases, the working chamber, made in the form of a bellows, is placed in a Dewar vessel with liquefied gas, the boiling point of which is lower than the boiling point of the gas in the chamber.

A known installation for testing materials for resistance to cavitation erosion in cryogenic environments (SU 351149 dated 09/13/1979, IPC G01N 0029/00), containing a cryostat filled with a refrigerant, placed in it a chamber with a working medium, a sample holder, a waveguide-emitting device and an elastic suspension for attaching its concentrator to the chamber, in which the waveguide-emitting device is placed in a cryostat, and the elastic suspension is installed in the concentrator oscillation unit.

A cavitation generator is known (SU 1136845 dated 01/30/1985, IPC V06V 1/16), containing a housing, a stator and a rotor coaxially installed in it, facing one another, the surfaces of which are made rough and between which there is a working chamber, inlet and outlet pipes , characterized in that, in order to reduce its dimensions and reduce energy losses, the housing and stator are made cylindrical, in the diametrical plane of which the axis of the cylinder is located, the rotor is in the form of a disk, cavities are made in the housing in the radial direction, communicating with the working chamber through holes .

A cavitation generator is known (SU 1168300 dated 23.07.1985, IPC B06V 1/16), containing a housing with nozzles for supplying and discharging liquid, a drive shaft placed in it, mounted on the last cavitator, made in the form of an impeller, characterized in that, with in order to reduce specific energy costs, the body is made cylindrical, and at least one of its inner walls is rough.

A device for cavitation wear of materials is known (RU 2309401 dated October 27, 2007, IPC G01N 29/00), containing a magnetostrictive transducer, an oscillation concentrator installed with the possibility of changing the gap between it and the test sample, a container with liquid and a mounting mandrel for the sample, characterized in that which additionally contains brackets of cylindrical shape with an impeller, fixing the position of the wear surface, made with the possibility of rotation around its axis and rolling over the wear surface of the tested sample, the base for fixing the brackets is rigidly connected to the body of the magnetostrictive transducer, the mounting mandrel contains a cavity with a spring and a valve, made with the possibility ensuring constant contact of the test specimen with the brackets.

A device is known for creating a pulsed loading mode of the executive bodies of technological machines (RU 2435992 dated 10.12.2011, IPC F15B 21/12, B06V 1/18), containing a housing, a piston with a rod and an oscillation generator associated with a cover, characterized in that the generator vibrations is placed in a glass coaxially located with the piston and rod, while the oscillation generator is connected to a membrane rigidly installed between the glass and the cover.

A cavitation generator is known (RU 2635142 dated 09.11.2017, IPC B01F 7/10, B01F 11/00), including a housing with an internal working chamber and with nozzles for supplying liquid to and from the chamber, a drive shaft placed in the chamber and fixed on shaft an activator in the form of a disk with cavitators of a certain shape installed along the radii of the disk along the normal to its surfaces, and similar fixed cavitators are installed on the end walls of the working chamber, characterized in that the cavitators are made in the form of truncated cones, their bases are rigidly fixed on movable disks and on the fixed walls of the chamber, and on the movable disks the truncated cones-cavitators are installed on at least one side of the disk along the radii of the disk along the normal to its surface.

A known installation for testing materials for strength at cryogenic temperatures (RU 142238 dated 20.07.2014, IPC G01N 3/18), containing a loading and measuring device, a sealed working chamber with a removable cover, a cold source connected by flexible cold pipes fixed on its surface with a zone cooling, the surface of which, together with the cold pipes, is located in the working chamber, as well as grippers for fixing the sample and a bellows, characterized in that the end surface of the cold source is located in the working chamber, and the rest of its surface is made heat-insulated, the working chamber has a double wall forming a closed cavity , part of this cavity covers the cold source, while the flexible cold pipes are fixed on the end part of the cold source.

A known installation for testing for cavitation erosion (RU 2710480 dated 12/26/2019, IPC G01N 29/00, G01N 3/56), containing an ultrasonic generator for generating vibrations, an ultrasonic transducer and a probe for amplifying vibrations, fixed vertically, the test sample and the container, in which a test is carried out, characterized in that a liquid supply nozzle is additionally installed in the installation, while the test sample is located above the exit of the liquid supply nozzle with the possibility of adjusting the distance to the exit of the nozzle, providing a cavitation effect; wherein the installation further comprises a pressure tank that provides liquid pressure in the nozzle, for which said pressure tank is located above the nozzle at a distance that provides the necessary pressure flowing from the nozzle liquid; while the installation is made with the possibility of continuous circulation of liquid through the nozzle.

All the above technical solutions are used to study cavitation processes, including testing of protective coatings.

The disadvantages of cavitation generators (SU 237817, SU 1136845, SU 1168300, RU 2635142) are the complexity of mounting and monitoring the samples under study, as well as the need to manufacture and use specialized equipment.

The disadvantages of devices and installations (SU 301187, SU 351149, RU 2309401, RU 2435992, RU 142238, RU 2710480), identified from the prior art, is the need to manufacture and use specialized equipment, and the process of material destruction is significantly different from the natural process of hydrodynamic cavitation on a real object.

The essence of the utility model

The technical result of the claimed utility model is to reduce the complexity of testing protective coatings for cavitation resistance by reducing the time of testing in conditions close to real, without the use of specialized equipment.

The technical result is achieved through the use of protective coatings for cavitation resistance testing of the impeller for testing protective coatings for cavitation resistance, which is a collapsible structure, containing a drive disk and a driven disk, which are tightened with screws and covered with protective spacers with grooves in which the blades are installed and blades with ledges coated with tested protective coatings, while the protective spacers are replaceable.

The claimed utility model ensures the achievement of a technical result. Without the use of specialized equipment, testing of protective coatings for cavitation resistance is performed by replacing the standard impeller of a centrifugal pump with the claimed utility model, which reduces the complexity of testing protective coatings for cavitation resistance by reducing the time for testing coatings in conditions close to real, with the possibility of prompt monitoring the condition of coatings.

Brief description of the drawings

In FIG. 1 shows an impeller for testing protective coatings for cavitation resistance.

In FIG. 1 adopted the following designations:

1. Driven disk.

2. Protective spacers with grooves.

3. Shoulder.

4. Screw.

5. Blade with ledges.

6. Leading disk.

Implementation of the utility model

The claimed utility model is installed in a centrifugal pump instead of a standard impeller. The tested protective coatings are applied to the blades 3 (Fig. 1). The blades 3 and 5 (Fig. 1) are installed in the grooves of the protective spacers 2 (Fig. 1), which, in turn, cover the drive disk 6 (Fig. 1) and the driven disk 1 (Fig. 1). The driving disk 6 (Fig. 1) and the driven disk 1 (Fig. 1) are centered between each other by blades with projections 5 (Fig. 1) and are pulled together by screws 4 (Fig. 1) after which the assembled impeller (Fig. 1) is installed instead of a standard impeller in a centrifugal pump. During operation of the centrifugal pump, due to flow separation on the blades 3 and 5 (Fig. 1), developed cavitation occurs, which destroys the protective coating deposited on the blades 3 and 5 (Fig. 1). To analyze the wear of materials, the centrifugal pump and impeller are periodically disassembled (Fig. 1). Analysis of the state of coatings can be performed visually, by weighing, etc. After a long test cycle, protective spacers 2 (Fig. 1) are replaced with new ones.

Claims (1)

Impeller for testing protective coatings for cavitation resistance, which is a collapsible design, containing a drive disk and a driven disk, which are tightened with screws and covered with protective spacers with grooves in which blades and blades with projections with test protective coatings applied to them are installed, at In this case, the protective spacers are replaceable.

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