Because the use of slurry pump is very extensive, the nature of the liquid is transferred sometimes is also a great difference, different work situations has different requirements of the pump flow and pressure, in order to meet the requirements of the pump performance in various places, there are so many kinds of pump, usually can be classified according to the working principle of the pump, and its use can provide lift. According to the working principle of the pump can be divided into positive displacement pump, vane pump and other type pumps three categories
Positive displacement pumps rely on volume changes periodically generated working volume suction and discharge liquid, when the work volume increases, the pump suction liquid; when decreases, the pump discharge liquid. Kinematic characteristics according to the work of this type Li in turn are divided into:
1. Reciprocating pump working mechanism for reciprocating motion. This type of pump is a piston pump, piston, diaphragm chestnut and so on.
2.Rotary pumps work agencies for fixed axis rotation. This type of pump is a gear pump, screw pump, gravel pump industry sliding vane pumps.
Vane chestnut rely one or several high-speed rotation of the impeller to promote fluid flow, to achieve liquid transport. According to the liquid in the flow direction of the pump vane pump in turn divided into:
1.Pump fluid flowing radically through the pump, the force pushing the liquid flow when the centrifugal force generated by rotation of the impeller.
(2) Axial fluid flow axially through the pump, the force pushing the liquid flow impeller axial thrust generated when the rotation.
3. Flow pump fluid in the pump flow to the pump shaft into a certain angle, the force pushing the liquid flow when the centrifugal force generated by rotation of the impeller and the axial thrust force.
4 – Vortex pump liquid in the pump for vertical vortex flow, relying on the impeller rotates promote vortices generated by movement of liquid suction and discharge liquid.
Other types of pumps are mostly relying on another fluid (liquid, gas) energy or kinetic energy hydrostatic transmission fluid. Thus, also called the hydrodynamic pump, such as jet pumps, water chestnut, etc. hammer.
The basic parameters of the main properties of gravel pump has the following:
1, the flow of Q
Flow is the amount of liquid gravel pump in unit time delivery out (volume or quality).
Volume flow with Q said, the unit is: m3/s, m3/h, l/s etc..
Mass flow with Qm said, the unit is: t/h, kg/s.
The relationship between mass flow and volume flow for:
Qm= ρ Q
In the formula ρ — liquid density (kg/m3, t/m3), normal temperature water P =1000kg/m3.
2, the head of H
The head is the unit weight of the liquid gravel pump pumping imported from the gravel pump (inlet flange gravel pump) to the gravel at the outlet of the pump (pump outlet flange gravel) energy increment. Effective energy is a Newtonian liquid obtained by gravel pump. The unit is N ? m/N=m, the height of liquid column gravel pump pumping liquid, habits, referred to as M.
3, speed n
Speed is the speed of gravel pump shaft unit of time, denoted by the symbol n, a unit of r/min.
4, NPSH NPSH
NPSH is also called the net positive suction head, is expressed mainly parameters of cavitation performance. NPSH in domestic use Δ H.
kg/m3）；
5, power and efficiency Selection basis of slurry pump
Gravel pump power is usually refers to the input power, which is the original motivation came a gravel pump shaft power, so it is also called the shaft power, represent by P ;
Effective power gravel pump is also called the output power, represent by Pe . It is the effective energy unit of time from the gravel pump delivery out of the liquid in the gravel pump.
Because the lift is the effective energy gravel pump output unit weight liquid obtained from the gravel pump, so head and the mass flow rate and acceleration of gravity, is the unit of time from the gravel pump output liquid obtained effective energy — namely gravel pump efficiency power:
Pe= ρ gQH (W) = gamma QH (W) formula ρ density — gravel pump liquid (kg/m3);
Severe gamma — gravel pump liquid (N/m3);
Q — gravel pump flow (m3/s);
H — gravel pump head (m);
G — the acceleration of gravity (m/s2).
Shaft power P and power Pe of power loss of gravel pump, the size of gravel pump efficiency measure. Gravel pump efficiency as the effective power and shaft power ratio, using η.
Post time: Jul-13-2021