QJ deep well pump selection and deep well pump head calculation

QJ deep well pump selection notes: (1) to determine the actual depth of the well H, hydrostatic Hi, water depth H and borehole diameter. (2) According to the pumping test, find the maximum possible water discharge Qmax and the corresponding maximum water level drop Smax, find the water level drop Sq when the unit flow rate, that is Sq = SmaxQmax. In the absence of accurate pumping test data, Qmax can be estimated as: Qmax = (2H-Smax) SmaxQ (2H-S) S where H- depth in the well, m; Q- pumping experiment When the water level is stable, The amount of water, msh; S - the water level drop in the well corresponding to Q, ie the distance from the clear water level to the stable water level, m; the maximum water level drop in the Smax-well, m, generally H2; Qmax - maximal for Smax The amount of water, m3h. QJ deep well pump selection steps: (1) to determine the type of deep well pump QJ Deep hole pump according to the diameter and well depth of the pre-selected well pump model. If the borehole diameter is 200mm, only 8JD or SD8 deep well pump should be selected to maintain enough clearance between well and pump. (2) Seeking water level drop According to the selected model, with reference to product samples, find its rated flow rate Qe, according to the following equation to find the water level drop when the flow. SM = SqQe (6-40) Where SM-water level drop, m, SM ≤ H2. (4) Calculate the total length of the water pipe in QJ deep well pump L = Ha + (1 ~ 2) () 6-42) where L-the total length of the water pipe, m. The calculated L value should not be greater than the maximum length of the wellhead given by the model pump in the product sample. (5) Calculate the total loss lift According to the diameter and flow of the water pipe, find out the frictional loss value h per 10m long water pipe, then the total loss of the water pipe is: △ Hz = 0.1hL (6-43) Where L- Water pipe total loss lift, m. (6) lift required head lift Hx = Hd + △ Hz (6-44) where Hx - QJ deep well pump lift to the head of the wellhead required lift. If the water is pumped to a certain height from the ground, then the above formula Hx plus pipeline above the ground water friction loss. (7) Determine the impeller series and the pump head Hx according to the obtained, check the product samples to determine the pump impeller series, so that the rated pump lift is not less than Hx, that He = KHx. Where K is the reserve factor, about 1.1 ~ 1.2.