Hello Mike,

You have the make and the type of the blower.

Is that all there is on the nameplate?

Is there any information on the nameplate of the electric motor?

By measuring:

- diameter of the inlet

- diameter of the outlet

- the length of the blower cylinder housing

- the heart distance between the 2 shafts

together with the rpm, it must be possible to recalculate the blower performance.

You measure and I will try to calculate.

all for now

Teus ■

Hello Mike, hello Teus,

let me look in our old product data base. I think I have the performance data sheets for this blower. On top of Teus' data please provide the pulley OD's and the motor rpm. That would be all we need to get you the performance data you have infront of you right now.

Do you know what kind of air flow and pressure you will need for the new application?

Safe travels.

Ralf ■

Hello Mike,

This is a blower with a maximum pressure service of 700mBar and with a 17 break KW you are looking at roughly 10m3/min, which is roughly 2500 blower RPM. Please let me know when you have the other information and I can help you with the flow rates and RPM.

Have a good weekend,

Ralf ■

Good morning Mike,

Good to hear you enjoyed your stay in Scotland.

The length of the blower cylinder housing of 42" (1066 mm) seems too long.

The length I need is actually the length of the rotor lobes, which can be measured outside between the faces of the end shields. (Not including the gearbox and oil casings at the end )

10" to 12" seems more likely.

The 5" heart distance (127 mm ) was expected.

What I am trying to calculate goes as follows:

Heart diameter is related to the lobe diameter

Displacing area is related to the lobe diameter (assuming a standard lobe design) and therefore related to the heart distance

The cylinder (lobe) length times the heart distance is then related to the displaced volume per revolution.

Multiplication with the rpm gives the internal displaced volume.

The motor power combined with the internal displaced volume gives the maximum pressure drop.

Asuming a normal volumetric efficiency for the blowersize gives the external volume flow at different pressures.

I now need your input to find out whether I did it right.

Have a nice day

Teus ■

Good evening Mike,

Ok, it worked.

The calculation spreadsheet is attached. In principle should this calculation cover all blowers.

The 4” inlet and the 4" outlet match nicely with the 5" H to H distance (see the attached drawing (pdf-file)

The calculated performance of 10.7 m3/min at 700 mbar corresponds nicely with the data from Ralf’s data sheet.

However, the rpm given by Ralf are likely incorrect.

If you want the blower table as well let me know. Easy to calculate now.

This is fun

Teus

Attachments

blowercalc (PDF)

calcblowerfromdimensions (PDF)

■

Good afternoon Mike,

Attached the "calculated table" for the blower

Have a nice time in Spain

Take care

Teus

Attachments

datablowerholmeshr12 (PDF)

■

Hello Mike,

did you get a chance to work this issue out? Would be cool to know how you faired with the performance of the blower. ■