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WorksheetsDay 39-Oct 29-worksheet-Diploma-Hydraulic pumps part 2
Total questions: 15
Worksheet time: 11mins
Fluid separation in a reciprocating pump occurs primarily when
Delivery valve closes slowly
Pump speed becomes excessively high
Air vessel is installed
Priming is not done
The function of an air vessel fitted on a reciprocating pump is to
Increase theoretical discharge
Reduce velocity fluctuations & save work
Reduce viscosity
Close delivery valve
Power required by a reciprocating pump is proportional to
(A·L·N)
ρgQ(hs + hd)
Length of suction pipe
Friction loss only
Purpose of air vessel on suction side is to
Reduce vane efficiency
Smoothen acceleration head
Increase slip
none
Slip is defined as
Qactual – Qtheoretical
Qtheoretical – Qactual
Cd × 100
none
Air vessel increases uniformity of discharge in a reciprocating pump.
True
False
When slip is zero, the theoretical and actual discharges are equal.
True
False
Assertion (A): Negative slip is possible in reciprocating pumps. Reason (R): The liquid continues to flow due to inertia even during part of the suction stroke.
Both A and R true; R correct explanation
Both true; R not explanation
A true, R false
A false, R true
Equation for % slip in terms of coefficient of discharge Cd= ……………..
(a)
Area of indicator diagram = L × (a) .
Fluid separation occurs at the beginning of __________ stroke and at the end of __________ stroke.
(a)
An air vessel contains ………at top and …………. at bottom.
(a)
Work saved in SARP by air vessel ≈ __________ %.
84.8%
65.2%
72.5%
91.3%
A pump has A = 0.01 m², L = 0.20 m, N = 60 rpm, hs = 3 m, hd = 7 m. Find the power (ρ=1000, g=9.81).The pump is double acting.
(a)
For a pump with Qth = 5.0 L/s and Qact = 4.6 L/s, what are the values of slip, % slip, and Cd?
(a)
