Here is a table of the theoretical HP consumption to
raise water x amount of distance y gallons per minute.
The height of the water column is indistinguishable from psi so
the two are plotted together at the top of the table.
This is theory only. The actual HP required depends on the
efficiency of the pump. A check on page 198 McMaster
Carr tells us a 3450 RPM 1/3 HP 110V 2.5 amp motor with a
nice looking centrifugal pump will pump 10 gpm at a 37 foot
head. From our chart that is .11 HP so centrifugal pumps are
about 33% efficient so triple these HP numbers
in the table. That is not to say the centrifugal
pump is this inefficient throughout out the RPM range of a
pump mounted on an engine. This is just a spot efficiency check.
The HP to drive the pump ultimately must come from the engine.
An alternator is about 80% efficient and an electric motor is also about
80% efficient and a centrifugal pump is about 50% efficient
so we are looking at .8 x .8 x .33 for an overall efficiency for
the electric pump of 21% while that of the direct drive
pump is about 33% efficient. Sounds like an electric car.
I uploaded my program on here so all you engineers can check
my calculations.
It will be interesting if Bill hooks up an ammeter to that
one HP table saw motor of his.
Paul Lamar
The AirCraft Rotary Engine NewsLetter. Powered by Linux.
ACRE NL web site. http://home.earthlink.net/~rotaryeng/
Copyright 1998-2002 All world wide rights reserved.
Head '_ __ 6.8__ 9.0__11.3__13.5__15.8__18.0__20.3__22.5__24.8__27.0__29.3__31.5__33.8__36.0
PSI 10____15____20____25____30____35____40____45____50____55____60____65____70____75____80
2 0.003 0.004 0.005 0.007 0.008 0.009 0.010 0.011 0.012 0.013 0.014 0.015 0.016 0.017
4 0.007 0.009 0.011 0.013 0.015 0.017 0.020 0.022 0.024 0.026 0.028 0.031 0.033 0.035
6 0.010 0.013 0.016 0.020 0.023 0.026 0.029 0.033 0.036 0.039 0.043 0.046 0.049 0.052
8 0.013 0.017 0.022 0.026 0.031 0.035 0.039 0.044 0.048 0.052 0.057 0.061 0.065 0.070
10 0.016 0.022 0.027 0.033 0.038 0.044 0.049 0.055 0.060 0.065 0.071 0.076 0.082 0.087
12 0.020 0.026 0.033 0.039 0.046 0.052 0.059 0.065 0.072 0.079 0.085 0.092 0.098 0.105
14 0.023 0.031 0.038 0.046 0.053 0.061 0.069 0.076 0.084 0.092 0.099 0.107 0.115 0.122
16 0.026 0.035 0.044 0.052 0.061 0.070 0.079 0.087 0.096 0.105 0.113 0.122 0.131 0.140
18 0.029 0.039 0.049 0.059 0.069 0.079 0.088 0.098 0.108 0.118 0.128 0.137 0.147 0.157
20 0.033 0.044 0.055 0.065 0.076 0.087 0.098 0.109 0.120 0.131 0.142 0.153 0.164 0.175
22 0.036 0.048 0.060 0.072 0.084 0.096 0.108 0.120 0.132 0.144 0.156 0.168 0.180 0.192
24 0.039 0.052 0.065 0.079 0.092 0.105 0.118 0.131 0.144 0.157 0.170 0.183 0.196 0.209
26 0.043 0.057 0.071 0.085 0.099 0.113 0.128 0.142 0.156 0.170 0.184 0.199 0.213 0.227
28 0.046 0.061 0.076 0.092 0.107 0.122 0.137 0.153 0.168 0.183 0.199 0.214 0.229 0.244
30 0.049 0.065 0.082 0.098 0.115 0.131 0.147 0.164 0.180 0.196 0.213 0.229 0.245 0.262
32 0.052 0.070 0.087 0.105 0.122 0.140 0.157 0.175 0.192 0.209 0.227 0.244 0.262 0.279
34 0.056 0.074 0.093 0.111 0.130 0.148 0.167 0.185 0.204 0.223 0.241 0.260 0.278 0.297
36 0.059 0.079 0.098 0.118 0.137 0.157 0.177 0.196 0.216 0.236 0.255 0.275 0.295 0.314
38 0.062 0.083 0.104 0.124 0.145 0.166 0.187 0.207 0.228 0.249 0.269 0.290 0.311 0.332
40 0.065 0.087 0.109 0.131 0.153 0.175 0.196 0.218 0.240 0.262 0.284 0.305 0.327 0.349
CLS
'water weighs 65 pounds per cubic foot
'one foot of water is 65/144 or .45 psi per foot
'to get feet
OPEN "pumphp.dat" FOR OUTPUT AS #2
PRINT #2, "Head '_ ";
FOR psi = 15 TO 80 STEP 5
feet = .45 * psi
PRINT #2, "__"; USING "##.#"; feet;
NEXT psi
PRINT #2,
PRINT #2, "PSI 10";
FOR x = 15 TO 80 STEP 5
PRINT #2, "____"; USING "##"; x;
NEXT x
PRINT #2,
FOR gpm = 2 TO 40 STEP 2
PRINT #2, USING "##"; gpm;
FOR psi = 15 TO 80 STEP 5
feet = .45 * psi
galpsec = gpm / 60
lbpsec = galpsec * 8
HP = (lbpsec * feet) / 550
PRINT #2, USING "##.###"; HP;
NEXT psi
PRINT #2,
NEXT gpm
CLOSE
SHELL "more < pumphp.dat "
END
