【 Weak current College 】 self-priming centrifugal pump operating principle and fundamental building

Self-priming centrifugal pump operating principle and fundamental construct a, self-priming centrifugal pumps of the basic structure is composed of six parts of
Self-priming centrifugal pump of the basic structure is composed of six parts are the pump body, impeller, shaft, bearing, sealing rings, stuffing.
1. self-priming centrifugal pump impeller is the core part of its speed and high output, the impeller blades also play a major role in assembling the front impeller through static balance test. Impeller and external surface requirements on smooth, to reduce the flow of friction loss.
2, pump body also called casing, it is the body of the pump. Play a supporting role, and work with the fixed housings for carrier phase connection.
3. pump's role is to lend coupling and electric motor is connected, the motor's torque to the wheel, it is passed the main parts of mechanical energy.
4. bearings is set in the shaft of the widget on the support shaft, ball bearing and bearing two. Rolling bearings use butter as lubricant filling to appropriate General-2/3 to 3/4 size too much and too little will generate heat, and noise and heat! plain bearings are using transparent oil lubricants, come to the oil-water mark. Too much oil seeps along the axle and floating base, too little overheated bearing will burn out cause accidents! in the pump running bearing temperature up to 85 degrees usually runs at 60 degrees, if you will find the reasons for the high (whether there are sundries, oil is black, if water intake) and processed in a timely manner!
5, sealing rings, also known as reducing ring. Pump housing and impeller of the gap between the General Assembly had caused pump high pressure area of the Park's this gap flow to the area of low pressure, impact, efficiency of pumps water discharge reduces! clearance is too small will cause the impeller and the pump must wear of friction produces. In order to increase the return resistance of the internal leakage reduction, delaying the impeller and the pump housing, service life of the pump housing and impeller within margin of foreign aid in conjunction with the Department is equipped with sealing ring, sealing gaps remain between the 0.25 ~ 1.10mm.
6, primarily by filling the stuffing box, seal ring, packing, packing gland, dip pipe. The role of the stuffing box is mainly to closed casing and the gap between the shaft and does not let the water flow in pump does not flow out to won't allow outside air into the pump. Always maintain the pumps in the vacuum pump and packing when frictions thermal soon rely on dip pipe live water to water circles make packing cooling! keep the normal operation of the pump. So in the pump running circuit check on stuffing of check is especially! running 600 hours will be replaced on the packing.
2. self-priming centrifugal pump with flow components
Self-priming centrifugal pump of flow components are: inhalation room, impeller, press out the room in three parts. Impeller room is the heart of the pump, and flow part of core. Pump through the impeller on the liquid power, increase their energy. Impeller at the direction of the liquid flow out into three categories:
(1) runoff impeller (centrifugal impeller) liquid is along the axis perpendicular to the direction and flow out of the impeller.
(2) cross-flow impellers (mixed-flow impeller) liquid is the direction along the axis inclined flow out of the impeller.
(3) axial-flow impeller liquid flow direction and axis parallel.
Impeller by inhalation of divided into two categories:
(1) single-suction impeller (i.e. impeller from side inhalation liquids).
(2) double-suction impeller (that is, both sides of the impeller from the inhalation of liquid).
Impeller press cover form is divided into three categories:
(1) closed impeller.
(2) open type impeller.
(3) half-open impeller.
Which the application is very wide closed impeller, such single-suction impeller double-suction impeller are owned by this form.
III. self-priming centrifugal pump works
Self priming centrifugal pump is the working principle: self priming centrifugal pump can be sent out the water is due to the centrifugal force. Water pump in the work, the pump body and fles must tank filled with water line into the vacuum State, when the impeller rotation, rotate quickly leaves to water, turning water under the effect of the centrifugal impeller in, pump water was thrown out, the central part of the formation of the impeller vacuum area. The water in the water the atmospheric pressure (or pressure) under pressure through the network to the inlet pipe. This cycle, can achieve continuous pumping. Here it is worth mentioning: self priming centrifugal pump starts to pump shell before must be filled with water after the start, otherwise will result in the pump body heat, vibration, water discharge reduces damage to the pump (hereinafter referred to as "CAVITATION") creates the equipment accident!
Self-priming centrifugal pump of great variety, the classification of the common following ways 1 minute by inhalation: impeller sucks-self priming centrifugal pump-priming type sucks the centrifugal pump. 2 press the number of points: single-stage impeller sucks the multistage centrifugal pump self-priming centrifugal pumps. 3 press the impeller structure: open type impeller sucks the centrifugal pump semi-open impeller sucks the centrifugal pump closed impeller self-priming centrifugal pumps. 4 press working pressure: low-voltage in MV self-priming centrifugal pump self-priming centrifugal pumps and high-pressure self-priming centrifugal pump self-priming centrifugal pumps with vertical sides.
4, the following describes the self-priming centrifugal pump of some important performance curve.
Water pump performance parameters such as the flow q lift h shaft power N speed n efficiency η between certain relations. They measure between changes in relationships withcurves, this curve is called pump performance curve.
Water pump performance parameter change relations between each other and their conditionality: first of all to the pump for the top speed as a prerequisite.
The pump performance curve mainly has three curves: flow — lift curve, flow — the power curve, flow-efficiency curve.
A, flow-lift characteristics curve
It is self priming centrifugal pump performance curve of Basic. Specific speed is less than 80 self priming centrifugal pump with rising and falling characteristics (both sides of the Middle Hill, curved), called the hump performance curve. Specific speed at 80 to 150 between self priming centrifugal pump performance curve with flat. Specific speed in more than 150 self-priming centrifugal pump performance curve with a steep descending. In General, when traffic hours, head on, with the flow of the desk-to-increase liftGradually decline.
B, flow — power curve
Shaft power is increased with the flow, when the flow q = 0, the corresponding shaft power is not equal to zero, and for a certain value (about the normal operation of the 60 per cent). This power is mainly consumed in the mechanical loss. This pump is filled with water, if the long run, will cause the pump to temperature rising, casing, bearing be fever, severe may make the pump body thermal deformation, we called "stuffy head", when the lift is the maximum value, when the water valve is open, the traffic will gradually increase, shaft power is slowly increasing.
C, flow-efficiency curve
Its curved shape, Xiangshan head when traffic is zero, efficiency is equal to zero, as the traffic increases, the efficiency is also gradually increased, to a certain value fell after the efficiency, efficiency is the highest point in the most efficient, the efficiency is around is relatively high, the area known as high-efficiency district.
5. reasonable configuration, security, run, high quality water supply
These four aspects of understanding the self priming centrifugal pump structure, working principle and characteristic curve, how reasonable configuration motor pump power, it is necessary to ensure the safe operation of the pump, water quality, reduce production costs, reasonable configuration pump power, play pumps best work zone safety run, I plant to supply the actual situation of the foot is the rational allocation of the equipment's importance, reliability, and affordability.
1, machine pump equipment reasonable configuration. Water plant's main task is to ensure that the whole city to's production and domestic water, South factory original, the maximum quantity of 90 000 tons, into the water, the water discharge to meet regional pressure, but the last ten years, with the municipal eviction, the migration of water users, water supply is reduced, improving the quality of life with the people, the demand for water quality, the factory water reaches 0.3NTU.
How to ensure good quality water supply, the company has adopted a series of measures: (a) adjustment machine pump device allocation, the best combination of man and machine. (B) intensify scientific and technological innovation, a lot of capital renovation of the original backward water purification equipment. (C) invest, transforming the old equipment, old network, improve water conditions, the installation of static mixer, etc. (D) install 40 sets of instruments, the use of modern water quality monitoring system, the entire process of monitoring and control, ensuring high quality water. These measures fully illustrates the machine pumps and water purification equipment, the importance of proper configuration.
2, the safe operation of the pump equipment reliability. In order to ensure the safe operation of the pump equipment, business-to-machine pump device management more standardized, the annual big maintenance, monthly secondary maintenance, daily level maintenance system, the ISO9002 quality management, it is necessary to ensure the safe operation of the pump equipment of various measures in order to ensure the safe operation of reliability, operational skills of the workers, to improve the quality of training, safety rules for implementation should be strictly enforced, they secure operation system implementation is to ensure that the machine pump equipment running reliability guarantees.
3. safe operation of the pump equipment of economics. When it comes to economics is the enterprise water costs, including electricity, alum, chlorine, ammonia, in the most secure operation mode, the best scheduling mode, the minimum cost of water, to control the economic activities of enterprises, improve economic efficiency, enterprise has accumulated some experience. Such as: the most secure operation mode, Shanghai's urban water supply pipe network is interconnected, have the control room to control the company Centre districts of water pressure too high easily tubes, to the people, national cause property damage, water pressure too low, some users of water, causing the negative image of the enterprise. Therefore, to maintain the pressure in the daytime is around 30-35 kPa, the pressure in the night area 30 following kPa. According to the requirements of pipeline pressure, daytime open high-lift pump, night driving high-and low-lift combinations, effective control of the out-of-the-water pressure to ensure that the regional network and hotel high water, the use of the best machine pump combination, both saving power consumption, and reasonably control pressure, these methods ensure the safe operation of the pump equipment of economics.
With the continuous development of science and technology, modernization of water pump, also reduces the number of people-management operations. Now most of the computer monitor's automatic operation mode, the operator's own quality place high demands. Because a single pump exception conditions affect the whole network of various water systems, resulting in serious consequences. After several years of practical work and theory of learning and knowledge to practical work, reasonable arrangements for water allocation and scheduling, utilizing the characteristics of various pumps using minimal power reaches the maximum yield of pump, running at its best. And safety, quality, and low consumption of water!