The installation height of the centrifugal pump depends on whether cavitation occurs in the centrifugal pump, and the cavitation of the centrifugal pump is closely related to the vaporization of the liquid being transported. Therefore, a special case of the vaporization of the liquid should be studied—boiling. And the pressure on the liquid surface when the liquid boils - the saturated vapor pressure. How does centrifugal pump cavitation happen: It can be found in daily life that when water is heated to 100'C, the water boils and turns into water vapor and emits into the atmosphere. As the altitude increases, the temperature at which the water boils decreases. This is because as the altitude increases, the air gradually becomes thinner, the concentration of air molecules on the water surface decreases, and the atmospheric pressure also decreases, and the pressure formed by the water molecules escaping from the water is closer to the atmospheric pressure. When the pressure of water vapor is equal to atmospheric pressure, water boils, so when a liquid boils at a certain temperature, the pressure above the liquid surface is called the saturated vapor pressure of the liquid at that temperature. It should be clear that various liquids have different vaporization rates, boiling temperatures and pressures due to their different properties, and therefore their saturated vapor pressures are also different. 2BE1 Series Liquid Ring Vacuum Pump

The air-cooled high-temperature heat transfer oil pump is also called heat transfer oil pump, high-temperature heat transfer oil pump and heat transfer oil circulating pump. Its structure and performance make it widely used and popularized in different industries. It can withstand high temperature and has good sealing performance at high temperature. It is a major leap in technology in the oil pump industry. It is applicable to petroleum and chemical industry, oil industry, synthetic fiber industry, textile printing and dyeing industry, plastic and rubber industry, paper industry, wood industry, construction industry and other industries. In addition, ry high-temperature heat transfer oil pump is also widely used in machinery industry, food industry, pharmaceutical production, oil supply circulation system of hot oil furnace and hot oil heating circulation system. But how to use the heat transfer oil pump correctly to improve its efficiency? Here are some points we can analyze and refer to: Accurate use method of hot oil pump: First, after the heat transfer oil pump and pipeline are installed, whether using water pressure or air pressure, the inlet and outlet valves of the heat transfer oil pump must be closed before pressure test, so as to prevent damage to the seals and oil leakage. Boot preparation (1) Clean up the site, unscrew the bearing seat screws and add heat transfer oil as lubricating oil (2) Before start-up, fill the heat transfer oil pump with the heat transfer oil delivered to drive out the air in the heat transfer oil pump. At this time, the gate valve on the pipe at the outlet of Shanghai Zhengao Pump Manufacturing Co., Ltd. shall be closed (3) The delivered heat transfer oil shall be heated evenly before start-up, and the preheating is carried out by using the delivered heat transfer oil continuously through the pump body Preheating scale: the temperature of the pump shell of the heat transfer oil pump shall not be lower than the inlet oil temperature by 40 ℃, and the preheating speed shall be 50 ℃ / h. during startup preheating, loosen the side nut on the pump foot by 0.3-0.5mm, and tighten it after preheating (4) When moving the coupling pump by hand, it should roll flexibly 2BE liquid ring pump in mining vacuum filter of application

Centrifugal pump is a general fluid machinery widely used in chemical industry system. It has the advantages of wide performance adaptability (including flow, pressure head and adaptability to the properties of conveying medium), small volume, simple structure, easy operation and low operation cost. Generally, the flow and pressure head of the selected centrifugal pump may be inconsistent with the requirements in the pipeline, or due to changes in production tasks and process requirements, it is required to adjust the flow of the pump, which is essentially to change the working point of the centrifugal pump. The working point of centrifugal pump is determined by the characteristic curve of pump and pipeline system. Therefore, changing any characteristic curve can achieve the purpose of flow regulation. At present, the flow regulation methods of centrifugal pump mainly include regulating valve control, variable speed control, parallel and series regulation of pump, etc. Due to the different principles of various regulation methods, in addition to their own advantages and disadvantages, the energy loss is also different. In order to find a flow regulation method with low energy consumption and energy saving, * * * better understand the relationship between the flow regulation mode of centrifugal pump and energy consumption. 1. Main modes of pump flow regulation 1.1 change pipeline characteristic curve The simple way to change the flow of centrifugal pump is to use the opening of pump outlet valve to control. Its essence is to change the position of pipeline characteristic curve to change the working point of pump. 1.2 change the characteristic curve of centrifugal pump According to the law of proportion and the law of cutting, changing the speed of the pump and changing the pump structure (such as cutting the outer diameter of the impeller) can change the characteristic curve of the centrifugal pump, so as to adjust the flow (and change the pressure head at the same time). However, for the working pump, the method of changing the pump structure is not convenient, and due to changing the pump structure, the universality of the pump is reduced. Although it is economical and convenient to adjust the flow at some times, it is rarely used in production. Here, only the method of changing the speed of centrifugal pump and regulating flow is analyzed. When the pump speed is changed to adjust the flow from Q1 to Q2, the pump speed (or motor speed) decreases from N1 to N2. When the speed is N2, the pump characteristic curve Q-H and pipeline characteristic curve he = H0 + g1qe2 (pipeline characteristic curve does not change) intersect at point A3 (Q2, H3). Point A3 is the new working point after adjusting the flow through speed regulation. This regulation method has obvious, fast and reliable regulation effect, which can prolong the service life of the pump and save electric energy. In addition, reducing the speed can effectively reduce the NPSHr of the centrifugal pump, keep the pump away from the cavitation area and reduce the possibility of cavitation of the centrifugal pump. The disadvantage is that changing the speed of the pump requires changing the speed of the prime mover (usually the motor) through frequency conversion technology. The principle is complex, the investment is large, and the flow regulation range is small. 1.3 series and parallel adjustment mode of pump When a single centrifugal pump cannot meet the conveying task, the parallel or series operation of centrifugal pumps can be adopted. Using two centrifugal pumps of the same model in parallel, although the pressure head changes little, the total conveying flow is increased, and the total efficiency of the parallel pump is the same as that of a single pump; When the centrifugal pump is connected in series, the total head increases and the flow changes little. The total efficiency of the series pump is the same as that of a single pump. 2. Energy consumption analysis of pump under different regulation modes When analyzing the energy consumption under different regulation modes, this paper only analyzes the two widely used regulation modes: valve regulation and pump variable speed regulation. Because the purpose of parallel and series operation of centrifugal pump is to improve the pressure head or flow, it is not widely used in the field of chemical industry. 3. Conclusion For the two main flow regulation modes of outlet valve regulation and pump variable speed regulation commonly used in centrifugal pumps, the energy consumption saved by pump variable speed regulation is much greater than that of outlet valve regulation, which can be seen from the power consumption analysis and comparative analysis of the two. The relationship between flow and head of centrifugal pump can more intuitively reflect the energy consumption relationship under the two regulation modes. Reducing the flow through variable speed regulation of the pump is also conducive to reducing the possibility of cavitation of the centrifugal pump. When the flow decreases, the greater the energy-saving efficiency of variable speed regulation, that is, the greater the power loss of valve regulation. However, when the pump speed changes too much, it will reduce the pump efficiency and exceed the range of pump proportional law. Therefore, in practical application, we should consider many aspects and synthesize a good flow regulation method between the two. Vacuum Pump Heat Treatment Guide,Heat Treatment Equipment Liquid Ring Vacuum Pump