00:01
Hello students, in this question we have 37 cm diameter centrifugal pump which is running at 2140 rpm with water at the temperature of the water at 20 degrees celsius.
00:18
So we have the different rates of performance data that is given.
00:24
So two identical pumps of the above characteristics 37 cm in diameter 2140 rpm.
00:33
Two pumps are used to pump water vertically upward.
00:37
So this is the two pump setup.
00:39
This is the first pump and this is the second pump.
00:41
Vertically you have to pump the water upward at a height of 100 meters of commercial steel pipe.
00:52
So should the two pumps be set up in series or parallel? what is the proper pipe diameter for the most efficient operation? so the series and parallel the choosing of series and parallel.
01:08
So when pumps are put in series then the total head so the head will be added.
01:16
So h1 plus h2 will be the total head h.
01:22
When they are in parallel the flow rates is additive but the head remains the same.
01:26
So the flow rates remains the same in here.
01:31
So that is flow rate q will remains the same is equal to same but the head remains changing added.
01:42
So when they are in this is it for the case in series but in parallel q will be equal to q1 plus q2 but h will remain the same.
01:55
So this is the setup for pump here.
01:59
So this is the basic format in series and parallel.
02:03
Now our expectation is we need to have a head of 100 cubic meters.
02:11
So 100 cubic meters 100 meters head it has to have.
02:16
So we need a minimum head of 100 meters.
02:20
So we know that the pump has a head at 100 kilowatts.
02:25
It has a head of 105.
02:27
So as per the data you can see that the flow rate q is going to increase increase and the head value get to decrease.
02:39
So it's decreasing as you go further and the power consumption is going to increase.
02:46
So we want a 100 meters minimum head.
02:51
Right.
02:51
So we can take the value of 105 104 and 102 for safety reasons we don't go for 100.
02:59
So we have the first three first three in parallel connection is ok.
03:10
Right.
03:11
So if you want higher flow rate so that means the flow rate is going to increase.
03:18
If you increase the whole thing so for you to have a flow rate of more than required.
03:27
So we need a flow rate which is reasonable...