H2—淹没深度。 即进水管口至水面的距高,h≥(1.5.20)，最小不得小于0. 5m,水面应以旱季最低动水位的水面来确定:
C--水面至池 面的距离，注意此时水面应以雨季最高动水位确定，一般取 0.3~0.5m。
进水池的宽度要考虑进水管与壁面的距离，最小应取(1.25 ~ 1.5)D，所以进水池的宽度B≥3D,泵应布置在中间。若是多台泵布置，为防止相互干扰、夺水，两台泵之间要有一定的距离，最小应取(2.5 ~ 3.0)D,有时,因考虑泵检修的需要,还可能要大一些。
Installation position of slurry pump geometric installation height of pump
I. geometric installation height of pump
The geometric installation height of the pump refers to the vertical height from the center line of the pump shaft to the liquid level. The geometric installation height of the pump is mainly determined from the following two aspects: one is limited by the cavitation performance of the pump, that is, it cannot be too high; the other is the risk of being submerged, that is, it cannot be too low. In addition, construction requirements and investment cost shall be considered.
(1) cavitation performance limit: it can be calculated and determined according to formula (3-11) or formula (3-14) in Section IV of Chapter III, namely:
(2) inundation hazard: when the water level rises in rainy season, the danger of pump and motor being inundated shall be prevented.
II。 Distance between pump and water source
The pump shall be close to the water source as far as possible, which can reduce the length and resistance loss of the water inlet pipeline. However, in order to make the liquid smoothly inhaled into the pump, there shall be more than 3D straight pipe section in front of the pump suction port. In order to reduce the length and elbow of the water inlet pipe, the water inlet of the pump shall face the water source direction.
III. requirements for water inlet tank
Pumps do not always have to enter the pool, such as small pumps, well pumps. But for large pumps, in order to make the water flow stable and convenient for maintenance, there is always a water inlet tank. The design principle of the water inlet tank is: the water flow shall be stable and uniform, the flow velocity shall not be too large, and vortex shall be avoided as far as possible.
安徽快3开奖结果1。 Size of water inlet tank
Figure 6-1 shows the minimum size requirements for the intake basin.
(1) minimum depth of water inlet tank H
In the formula, H1 is the distance between the inlet pipe and the oil bottom, H1 ≥ (07-08) d. but the smaller one shall not be less than 0.3m
H2 - submergence depth。 That is, the distance from the water inlet to the water surface, H ≥ (1。5。20), shall not be less than 0。5m, and the water surface shall be determined by the water surface with the lowest dynamic water level in dry season:
C -- distance from water surface to pool surface. Note that the water surface shall be determined by the highest dynamic water level in rainy season, generally 0.3-0.5m.
(2) width of water inlet B
The width of the water inlet tank should consider the distance between the water inlet pipe and the wall, and the minimum should be (1.25 ~ 1.5) d. therefore, the width of the water inlet tank B ≥ 3D, and the pump should be arranged in the middle. If multiple pumps are arranged, in order to prevent mutual interference and water grabbing, there should be a certain distance between the two pumps, with a minimum of (2.5 ~ 3.0) d. sometimes, due to the need of pump maintenance, it may be larger.
If there is no water inlet, the pump can be arranged according to the above requirements。
If the water inlet tank is not designed properly。 In addition, since the vortex occurs after the opening of the system increases, the remedy can be improved according to several methods to prevent the vortex in Fig。 6-2。
Fig. 6-2 (a) is the inlet of other water inlet, 1D from the water inlet pipe, insert a vortex prevention plate.
安徽快3开奖结果Fig. 6-2 (b) is a vortex prevention plate added horizontally in the back wall water of the water inlet pipe.
Fig。 6-2 (c) is to add a cover around the water surface of the water inlet pipe, and the flow on the water surface can be reduced and floated with the rise of the water surface。
Fig. 6-2 (d) is to add vortex prevention plate on both sides of the water inlet pipe.
The above methods can be used as some remedial methods when vortex occurs, which can play a certain role.
2。 Arrangement of water inlet tank
Although the inlet tank meets the size requirements, due to improper arrangement, there will also be vortex or interference, water grabbing between the two pumps and other phenomena, which will affect the normal operation of the pump, especially for large-diameter pumps, the correct arrangement is more important。
Figure 6-3 shows good and bad examples of several layout forms for reference.
3。 Trash screen
If the liquid level of the oil delivery is very dirty, it is not enough to rely on the protection net of the water inlet pipe alone. There is often a risk of blocking or partially blocking the inlet protection net, resulting in the reduction of pump flow and even more serious cavitation of the pump. At this time, it needs to be at the inlet of the water inlet pool or at the water inlet
The pipe shall be provided with trash screen around which the inclination shall be 45 ° ~ 60 °. When there is a lot of sediment in the water, a sedimentation tank should be set up to reduce the wear of the pump.
Generally, the pump room is required to prevent the erosion of rainwater and sand. For horizontal pump, the water inlet can be arranged outside the pump room, and for vertical pump, it can be arranged above the water inlet or well.
The pump room shall have a large enough area, and there shall be a certain distance between the pump and the wall, between the pump and the pump, so as to facilitate the operation during maintenance.
The pump room shall be of sufficient height to facilitate lifting during installation. If the height of pump room is not enough. It can be solved by opening a skylight on the top of the pump house, and lifting equipment shall be set for the pump house of large pump.
The pump room should not be too far away from the transformer to prevent too much line voltage drop。 Slurry pump