Pumps are machines that transport liquids or pressurize liquids. It will be the prime mover mechanical energy or other external energy transfer to the liquid, so that the liquid energy increases, mainly used to transport liquids including water, oil, acid and alkali, emulsion, suspension and liquid metal, but also can be transported liquid, gas mixture As well as liquids containing suspended solids. Pump performance measurement of the technical parameters of flow, suction lift, lift, shaft power, water power, efficiency, etc .; according to different working principle can be divided into volume pumps, vane pumps and other types. Volumetric pumps utilize the variation of their working chamber volume to transfer energy. Vane pumps use the interaction of rotating blades and water to transfer energy, such as centrifugal pumps, axial flow pumps, and mixed flow pumps.

First, the pump vibration analysis

1, domestic vertical pump 28SLA-10 is a direct transformation from the horizontal pump. The vertical height between the motor base and the pump base is 4.3m and the drive shaft weighs 3t. Compared to the horizontal pump, it adds an intermediate drive shaft with a length of 3752mm and a diameter of 140mm. In the structure, in addition to the middle drive shaft with a bearing, without any modification. The long-term operating pressure of the four pumps is 0.7 ~ 0.85MPa. In the condition of high lift and large flow, such a high-gravity, high-quality system rotates at a high speed and the centrifugal force generated is very large, vibration. Coupled stent and pump out of the water connection stiffness is not enough, resulting in a large displacement of the pump and the connector. Displacement of the pump during operation results in a change in the bearing condition of the bearing. As the vibration increases, it is easy to generate heat. If the correction of displacement pump to improve bearing stress conditions, can reduce the vibration of the system.

2, rigid connection between pump and drive shaft. Due to manufacturing and installation reasons, the pump shaft is concentric with the drive shaft during operation, causing the pump to vibrate. The vibrations generated by motors, transmission shafts and other sources are also directly transmitted to the pump to form a superposition of vibrations to further increase the vibration of the pump. In addition, this rigid connection to increase the water pump bearing the external force, resulting in easy to heat the bearing, affecting the pump shaft.

Second, the transformation of the situation

For the above reasons, we have taken the following two steps to transform.

1, to strengthen the pipeline stiffness. Taking into account the more difficult for the pump to strengthen, take the outlet pipe in the pump welding "stiffener" approach. Along the direction of inlet and outlet water, flanges at both ends of the connection pipe between the outlet pipe and outlet valve at the outlet of the water pump are welded with 8 steel plates with a thickness of 32mm and a width of 100mm. Increase the stiffness of the steel pipe to reduce the amount of deformation, resistance to pump displacement. After measuring, stiffened, the displacement of pump A point dropped to 0.35mm.

2, the transformation of the transmission system. In order to reduce the motor, the vibration of the transmission shaft is transmitted to the water pump, and the rigid connection between the water pump and the transmission shaft is changed to a flexible connection. Use GB4323-84 elastic sleeve pin coupling, centrifugal pump maximum compensation displacement of 0.6mm, compensation angle of 1 ° 30? . In this way, the vibration of the motor and drive shaft can be compensated by the flexible coupling, and the vibration can not be directly transmitted to the pump.

Third, the transformation results

After the transformation, the vibration of the pump was reduced to 1.48cm / s from the vibration speed 4.3cm / s before the transformation According to the vibration intensity standard ISO2372-1974, it can be determined that the pump operates in the excellent zone. At the same time, the pump runs smoothly, the bearings only need normal maintenance, and the shaft of the pump is worn out, indicating that the reform is successful.

Brief description of hydraulic ejector

Structure and advantages:

Hydraulic ejector consists of body, cover, nozzle, nozzle plate, guide plate, diffuser and one-way valve and other components, the nozzle with multi-nozzle structure, in order to get a larger water vapor contact Area, is conducive to the heat exchange, get a better vacuum effect. Jet nozzle plate precision machining, high precision, so that the jet flow deflection, reduce pumping efficiency. The whole device has the advantages of compact structure and high intensity and is used in a vacuum evaporation system. Since the condensing function of the condenser can be combined with the pumping action of the vacuum pump in one device at the same time, the process flow is greatly simplified. Compared with the original With vacuum pump and the old condenser device, you can save to the vacuum pump, condenser, water separator and other equipment, and also has the following advantages:

(1) hydraulic ejector small size, light weight, compact structure. While the performance is relatively high, lower power consumption than the vacuum pump system, investment province.

(2) Simple operation Easy maintenance, without full-time personnel management, due to no mechanical transmission part, so the noise is low, without consumption of oil.

(3) It can be installed outdoor at the bottom, covering a small area, can save the plant floor area and installation costs.

The hydraulic ejector is a kind of mechanical device with three effective functions of evacuation, condensation and drainage. It is the use of a certain pressure of water flow symmetrically distributed into a certain angle of the nozzle spray, polymerization in a focus. As the jet flow velocity is high, so the formation of negative pressure around the chamber to produce a vacuum chamber, in addition to secondary steam and jet water directly contact, heat exchange, the vast majority of steam condensate into water, a small amount of uncondensed steam and not The condensed gas is also frictionized, mixed and squeezed by the jet of water at high speed and is removed through the diffuser to create a higher vacuum in the chamber. Water jet is widely used, mainly for vacuum and evaporation systems, vacuum pumping, vacuum evaporation, vacuum filtration, vacuum crystallization, drying, deodorization and other processes, sugar, pharmaceutical, chemical, food, salt, MSG, milk , Fermentation and some light industry, defense departments widely needed equipment. However, the current production of small hydraulic jet manufacturer, the variety is not complete, for which, after continuous improvement in recent years, the design, the use of multi-jet and steam ring (steering wheel) and other structures, and multi-stage pump water, low Installation, just install the height of 4.5 meters, improve and improve its performance, with a certain degree of advanced, is a vacuum condensing equipment innovation.

Belt Pulley