Regenerative Blower Questions

[Jim Beachler]

I have purchased a used CNC and I need a larger vacuum for it than what came with it. I have a 10hp regenerative blower for my original one. After looking around I have found that is not hp that determines the amount of vacuum. I found a 20 hp and a 10 hp that both have the same amount of max vacuum.

What I am wondering is what is the benefit of having a 20 hp over a 10 hp if they both pull the same vaccum?

[Dan Hintz]

Cripes, 10hp?! That's a beast any way you look at it. 20hp would likely suck the universe away

You care about two things Cubic Feet per Minute(CFM) and Static Pressure (SP)... think of CFM as "airflow rate" and SP as "suction power" (meh, unlucky coincidence on the acronym). If you're creating a lot of chips, you want a lot of CFM. If the chips are heavy and/or they have to travel a great distance (particularly upwards), more SP is in order.

If both of the motors pull the same SP, the 20 is likely to pull a lot more CFM (depends upon rotor design), and vice versa. I think you'll be plenty fine with your original unit, unless you have a shop that's a mile long.

[Jerome Stanek]

Cripes, 10hp?! That's a beast any way you look at it. 20hp would likely suck the universe away

You care about two things Cubic Feet per Minute(CFM) and Static Pressure (SP)... think of CFM as "airflow rate" and SP as "suction power" (meh, unlucky coincidence on the acronym). If you're creating a lot of chips, you want a lot of CFM. If the chips are heavy and/or they have to travel a great distance (particularly upwards), more SP is in order.

If both of the motors pull the same SP, the 20 is likely to pull a lot more CFM (depends upon rotor design), and vice versa. I think you'll be plenty fine with your original unit, unless you have a shop that's a mile long.

I think he is talking vacuum hold down not dust collection

[Dan Hintz]

Oh... well, then ignore what I said

[Jim Beachler]

Yes, I am talking about suction to the table. I hear people talking about how many hp they have in their vacuum. They will some times throw around large numbers such as 20 - 25 hp, one person said that they have 2 25hp pumps. But does hp really matter? What I am wondering is what is the benefit of having a 20 hp versus a 10 hp vacuum if they both pull the same amount of vacuum.

[Dan Hintz]

Well, to step back in (as my info wasn't incorrect, just aimed at the wrong target)...

You'll have a low CFM as the table itself will severely restrict the airflow, so don't pay as much attention to that. You want a high static pressure. But again, it's not just about hp... look at the motor specs beyond hp, look at CFM and SP.

[Jerome Stanek]

You will need more cfm when you start to cut through. A good dust collector can be a blessing or a curse the more chaff that is asucked up the more cfm you will need to over come the open areas

[Mike Heidrick]

Jim, what size inlet on each machine?

[Jim Beachler]

The 20 hp has a 3" inlet and the 10 hp has a 2 1/2" inlet. Both sizes will work as the table has 3 inch pipe. It can be reduced to the smaller if I need to.