Horse power needed to turn a 22" dia X 31" tall cylinder weighing about 250lbs @  500 to 1500 Rpm

Per request:  load is essentially inertia of the mass of the cylinder, and drag from the air around it, and friction of the  bearings, there is fluid running thru it but it's volume will remain constant.so I don't believe it matters. Not quite sure regarding your question of "load" (not my area of expertise)  Think of it being similar to a washing machine in the spin cycle..

Hi Robert,

As Bill pointed out there is very little horsepower needed for the spinning of the cylinder, friction with the air, or bearing friction if the bearings are good quality. The fluid that runs through it could present considerable load if it is being spun up to the 1500 RPM as it passes through the cylinder. This will be able to be calculated by determining the mass and volume of the fluid that enters the cylinder each second. This mass and volume will act as a cylinder of fluid that has to be accelerated from 0 to 1500 RPM each second. This will take a certain amount of energy and this will be supplied by the Horse Power of the motor. What we need to give you more information is an answer to these questions

1. What is the volume and specific gravity of the maximum amount of fluid that enters the cylinder each second of operation?

2. Are there vanes or other mechanisms, in the cylinder, that cause the fluid to spin up to full RPM. If not what is the assumed percent of full spin RPM that is expected for the fluid.

3. What is the Max RPM that is ever used.

4. To be very accurate the moment of inertia for the cylinder should also be calculated as this will dictate a baseline horse power needed to spin the cylinder alone from 0 to full RPM in a specified period of time.

If this is critical you should have an engineer or physicist look at the system. If it isn't critical you could go empirical and try a motor and see how well it handles the job and adjust the size of the motor up or down from there.

John

Hi Robert,

As Bill pointed out there is very little horsepower needed for the spinning of the cylinder, friction with the air, or bearing friction if the bearings are good quality. The fluid that runs through it could present considerable load if it is being spun up to the 1500 RPM as it passes through the cylinder. This will be able to be calculated by determining the mass and volume of the fluid that enters the cylinder each second. This mass and volume will act as a cylinder of fluid that has to be accelerated from 0 to 1500 RPM each second. This will take a certain amount of energy and this will be supplied by the Horse Power of the motor. What we need to give you more information is an answer to these questions

1. What is the volume and specific gravity of the maximum amount of fluid that enters the cylinder each second of operation?

2. Are there vanes or other mechanisms, in the cylinder, that cause the fluid to spin up to full RPM. If not what is the assumed percent of full spin RPM that is expected for the fluid.

3. What is the Max RPM that is ever used.

4. To be very accurate the moment of inertia for the cylinder should also be calculated as this will dictate a baseline horse power needed to spin the cylinder alone from 0 to full RPM in a specified period of time.

If this is critical you should have an engineer or physicist look at the system. If it isn't critical you could go empirical and try a motor and see how well it handles the job and adjust the size of the motor up or down from there.

John