Rituraman asked 1 year ago
A double acting reciprocating pump has a piston diameter of 260 mm and its stroke is 320 mm. The pump runs at a speed of 64 rpm and delivers 30 liters/s of water. Find
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Theoretical discharge in liters/s
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Coefficient of discharge
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Percentage slip.
R cotwell answered 1 year ago
GIVEN:
PISTON DIAMETER, d = 260 mm = 0.26 m
PISTON STROKE, L = 320 mm = 0.32 m
SPEED, N = 64 RPM
ACTUAL DISCHARGE, Qa = 30 liter / sec
SOLUTION:
1 ) CALCULATING THE THEORETICAL DISCHARGE ( Qt ) :
THE THEORETICAL DISCHARGE IS GIVEN BY;
Qt = A x L x ( 2 x N / 60 )
WHERE 2N REPRESENTS THE NUMBER OF STROKES PER MINUTE, THE COMPRESSOR BEING DOUBLE – ACTING.
A = CROSS-SECTIONAL AREA OF THE PISTON ( )
L = LENGTH OF STROKE ( m )
HENCE WE GET;
A = / 4 =
/ 4 = 0.0169
L = 0.32 m
N = 64 RPM
THE THEORETICAL DISCHARGE IS;
Qt = ( 0.0169 x 0.32 ) x ( 2 x 64 / 60 )
Qt = 0.036245 / sec
OR, Qt = 36.245 Liter / sec
ANSWER: THE THEORETICAL DISCHARGE IS, Qt = 36.245 Liter/sec
2 ) COEFFICIENT OF DISCHARGE ( Cd ) :
THE COEFFICIENT OF DISCHARGE ( Cd ) IS THE RATIO OF THE ACTUAL DISCHARGE ( Qa ) TO THE THEORETICAL DISCHARGE ( Qt )
Cd = Qa / Qt
Cd = 30 / 36.245
Cd = 0.8277
ANSWER: THE COEFFICIENT OF DISCHARGE IS, Cd = 0.8277
3 ) CALCULATING THE PERCENT SLIP :
THE PERCENTAGE SLIP IS GIVEN BY;
% SLIP =
% SLIP =
% SLIP = 17.23 %
ANSWER: THE PERCENT SLIP IS. % SLIP = 17.23 %
ANSWERS SUMMARY:
1 ) THE THEORETICAL DISCHARGE IS, Qt = 36.245 Liter/sec
2 ) THE COEFFICIENT OF DISCHARGE IS, Cd = 0.8277
3 ) THE PERCENT SLIP IS. % SLIP = 17.23 %