Views: 105 Author: Site Editor Publish Time: 2022-10-04 Origin: Site
(1) pressure: hydraulic engineering applications of the three screw pumps commonly used working pressure range is 2.5 ~ 20MPa, individual can be as high as 35 ~ 40MPa.
(2) displacement: screw in the meshing drive process, due to the formation of the cross-sectional area of the gear remains unchanged, so the sum of the area of each cavity to accommodate the working medium A is equal to a constant. When the active screw of the screw pump rotates a turn, the liquid filled in the spiral groove moves up a guide length £, so the displacement of the screw pump V available to accommodate the work of the media cavity area of the sum of A multiplied by the guide length for calculation. The displacement range of the screw pump is large, up to 25 ~ 1500mL/r.
(3) flow: screw pump flow range of 3 ~ 10000L/min, conveying materials with a screw pump whose flow can reach 200m/min.
(4) speed: due to the slender structure of the screw rotating inertia is small, no unbalanced eccentric mass in the rotating parts, and the suction channel is very smooth, so the permitted speed of the screw pump is high, the speed of small displacement pumps can be as high as 6000r/min, large specifications are also in the 1000 ~ 1500r/min above.
(5) power: a variety of screw pumps in the largest power of more than 600kW.
(6) volumetric efficiency: due to the difficulty of the screw top circle clearance and spiral surface on the engagement gap compensation, the volume efficiency of the high pressure screw pump is low, roughly the same as the fixed clearance structure of the gear pump, generally nv = 0.75 ~ 0.95. The volume efficiency curve of the screw pump is slightly concave with the rise in pressure, and also more closely related to the speed.
(7) flow pulsation and noise: theoretically, the working medium in the progressive cavity pump the masses only parallel to the axis of the screw in a straight line, of course, in practice due to the existence of internal and external friction they will also be dragged by the screw vice slightly tangential movement, but in any case this is a much calmer than other types of hydraulic pump continuous conveying process. This results in a screw pump with minimal flow pulsation and the resulting noise.
1. Screw pump in the design, there are many parameters to consider, including: 1, the installation of the inclination: the installation of the inclination refers to the angle of the spiral pump shaft to the horizontal plane. It directly affects the efficiency and flow of the pump. According to the relevant information, the inclination angle of each increase of one degree, the efficiency is reduced by about 3%. Generally think the inclination angle in 30 ° ~ 40 ° for the economy.
2, gap: gap refers to the gap between the spiral vane and the shell. The smaller the clearance, the smaller the water leakage loss, the higher the efficiency of the pump.
3, speed: spiral pump speed is slow, generally 20 ~ 80r / min. experimental evidence: spiral pump outer diameter is larger, the speed should be reduced.
4, lifting height: spiral pump only lifting height, and no pressure water height. Its lifting height is generally 3 ~ 8m.
5, spiral vane diameter: the larger the diameter of the pump vane, the higher its efficiency, spiral pump vane diameter and pump shaft diameter of the best ratio of 2:1.
6, the number of heads: the number of heads refers to the number of pieces of spiral vane, generally 1 to 4 pieces. They are separated by a certain distance around the pump shaft spiral up. The more the number of heads, the higher the pump efficiency. For a certain diameter of the spiral pump, each increase in the number of a vane head, lifting capacity increased by about 20%.
7, lead and pitch: spiral vane around the pump shaft spiral up 360 ° through the axis of the distance, that is, a lead into.
8, flow and shaft power: according to the actual demand for setting.