Chapter 9 : Pumps

Example 9.1 pg : 18

# Variables
D = 0.3;
L = 0.6;
N = 60.;
Hs = 5.;
Hd = 10.;
Ep = 0.8;
Qa = 0.075;

# Calculations and Results
A = (22./7)*(1./4)*D*D;
Rho = 1000;
g = 9.81;

F1 = Rho*g*Hs*A;
F2 = Rho*g*Hd*A;

TF = F1+F2;
print 'Total Force Required: %2.2f kN'%(TF/1000);


Q = (2*L*A*N)/60;
Qa = 0.075;
Slip = (Q-Qa)/Q;
print 'Percentage Slip: %2.2f Percent'%(Slip*100);


Cd = Qa/Q;

P = (Rho*g*Qa*(Hs+Hd))/Ep;
print 'Power input: %2.2f kW'%(P/1000);

Total Force Required: 10.41 kN
Percentage Slip: 11.62 Percent
Power input: 13.80 kW

Example 9.2 pg : 19

# Variables
Qa = 0.025;
Hm = 20;
L = 0.4;
D = 0.3;

# Calculations
A = (22./7)*(1./4)*D*D;
Slip = 0.02;
Q = 25/(1000*(1-Slip));

N = (Q*60)/(L*A);

# Results
print 'Speed of Pump: %2.2f RPM'%(N);

Speed of Pump: 54.11 RPM

Example 9.3 pg : 20

# Variables
Hs = 32.;
N = 1450.;
Eff = 0.85;
Q = 0.05;
Hfs = 1.;
Hfd = 6.;
Hm = Hs+Hfd+Hfs;
Rho = 1000.;
g = 9.81;

# Calculations
P = (Rho*g*Q*Hm)/Eff;

# Results
print 'Power Consumed: %2.2f kW'%(P/1000);

Power Consumed: 22.51 kW

Example 9.4 pg : 20

# Variables
Pm = 25.;
Em = 0.9;
Q = 0.063;
Hs = 4.;
Hd = 25.;
Rho = 1000.;
Hm = Hs+Hd;
g = 9.81;

# Calculations
Ph = Rho*g*Q*Hm/1000;
Ps = Em*Pm;
Ep = Ph/Ps;

# Results
print 'Efficiency of Pump: %2.2f Percent'%(Ep*100);

Efficiency of Pump: 79.66 Percent