One purpose of the experiment
1, to understand the basic structure of the mechanical seal;
2, grasp the principle of mechanical seals;
3, the mechanical seal test equipment, to master the mechanical seal installation, commissioning, commissioning and demolition of the method;
4, the rotational speed control method of measurement;
5, measure the liquid leakage.
Second, the experimental principle
1, mechanical sealing principle
Mechanical seal is at least one rotation axis perpendicular to the face in the liquid pressure and stretch compensation mechanism (or magnetic) and sealed with the role and supporting the merger to maintain the relative sliding paste consisting of a device to prevent fluid leakage (Figure 1) . Along with the development of industrial technology, sealed fluid pressure to increase and improve the speed of transfer axis, making the soft packing seal can not meet requirements; and as mechanical seal can be changed by selection or structure is easy to achieve the requirements, are widely used in chemical, petrochemical, paper, pharmaceutical, food and other process industries, mechanical devices (such as pumps, compressors, reactors, etc.).
1 - screws, 2 - spring seat, 3 - spring, 4 - ring supporting ring, 5 - ring, 6 - static ring, 7 - static ring supporting ring, 8 - Anti-resale
Sealing performance of the most important parameters may be sealed fluid leakage. Leakage Q is mainly affected by the impact of seal gap h, h is proportional to the cube. So a little change in seal gap h can lead to significant changes in Q leakage. For the this, set the gap between the seal faces to maintain the capacity of both a current and a key factor in seal design is a key factor in the future seal design. because the seal system, the existence of flexible support, making mechanical seal in the face clearance depends on the system dynamics. This includes flexible installation of kinematic components, system pressure and momentum, and seals of various dynamic characteristics. acting on the flexible support components of the pressure and momentum from several possibilities, including system sealing pressure, lubrication film between the seal faces pressure , flexible support and the state seal in contact with the mechanical contact, etc.. affect sealing of various origins and dynamics methods should be sealed in the future development to be considered.
In this study, the simply supported beam structure platform, installed in the shaft bearings on both sides of symmetrical motor side of the axis of rotation formed by two ball bearing box for support, bearing fixed in the welding of rigid shelves, use the other side Rolling to do support, to ensure that all parts of the concentricity and axial thrust balance. bearing box on the opening hole injection to be fully lubricated bearings inside the bearing. experimental system pump to boost water storage chamber in the medium after After pump, water piping and valves into the regulator chamber, the water regulator chamber design is intended to make the medium entering the sealed chamber when the pressure stabilized, and then into the sealed test chamber, through import and export of the two side of the cut-off valve regulated sealed test chamber of the media pressure. medium import and export in the chamber pressure gauge can be read. set the temperature control devices. regulator valve installed on the water chamber to ensure the safety of experimental system operation.
1 - three-phase motor, 2 - electromagnetic governor, 3 - coupling
4 - Block the pump, 5 - sealed chamber, 6 - mechanical seal system, 7 - gland
2 Principle of photoelectric tachometer
In this study DT2234A Digital Photoelectric speed sensor to complete the measurement of the speed, shaft speed to low speed (shaft speed to v ≤ 1800r/min range). In shaft glue reflector (aluminum foil), Photoelectric tachometer from DT2234A issued infrared, incident to the reflector in the reflection back DT2234A photoelectric tachometer. using reflection to measure the number of speed. It can be non-contact measurement, easy to use, and do not cause additional load of the system under test.
Third, laboratory equipment and materials for tools
Seal test rig, mechanical seal components, various screwdrivers, DT2234A photoelectric tachometer, aluminum foil, YB150 type pointer precision pressure gauge, measuring cup, etc.
4, experimental procedures
1, observe the basic structure of mechanical seals, mechanical seal on the demolition, clear assembly relation;
2, the mechanical seal re-assembled, and mastered the principle;
3, use test platform, installation of mechanical seal, the installation process should pay attention to installation requirements;
4, open test bed to observe the functioning of the mechanical seal;
5, during operation of the motor speed measurement;
6, observe how much pressure mechanical seal started to leak in and under the total amount of leakage;
7, power, mechanical seal will be removed from the test audience.
