Hi,
In my plant, we use a few Lab mixers for stirring-up chemicals and mixing them. Some of the mixtures, nearing their mixing times, can get rather thick and viscous.
In the past, a few Universal AC/DC motors (with Gear boxes and Speed Controllers) have served us well barring frequent carbon brush changes and repairs to the rheostats.
I was planning to install a 3ph AC Motor and VFD to replace one of the mixers.
Current Motor specs are;
With no gear box, motor is 2.5Amps 1 phase 220/230 50 Hz, 1/2 hp, 0.37 KW, 6000 rpm and 3.00 Kg-CM torque
A 42:1 gearbox is used which brings max speed to 140 rpm and max torque to 12.35N.
Limitations/Requirements:
- Single phase AC 230V. Lack of 3 phase supply in the mixing area. This was one of the reasons my predecessor bought the Universal AC/DC motors.
Understand that some VFDs accept single phase inputs and can still drive 3 phase motors.
- RPM control must be by a rotary knob/pot know as frequent changes are required – push button may not be durable in the long term.
I was considering the 186rpm/16Nm/0.37Kw (Box040) here http://www.rotomotive.com/tabelle_prestazionali_02.pdf
Now comes the difficult part – I have never bought a VFD – ever and haven’t the faintest idea on spec-ing those!
After reading on the web, I was able to gather that a sensor less Vector drive will maintain torque along the spectrum of speed and not cause severe torque issues at low rpm (we tend to run the drives along all rpm bands depending on thickness and quantity of the fluid).
Any help in this area will be appreciated.
I will be sourcing locally from India but I may be guided using AutomationDirect as a benchmark.
Thanks in advance.
Amit SETH
Xsailor
In my plant, we use a few Lab mixers for stirring-up chemicals and mixing them. Some of the mixtures, nearing their mixing times, can get rather thick and viscous.
In the past, a few Universal AC/DC motors (with Gear boxes and Speed Controllers) have served us well barring frequent carbon brush changes and repairs to the rheostats.
I was planning to install a 3ph AC Motor and VFD to replace one of the mixers.
Current Motor specs are;
With no gear box, motor is 2.5Amps 1 phase 220/230 50 Hz, 1/2 hp, 0.37 KW, 6000 rpm and 3.00 Kg-CM torque
A 42:1 gearbox is used which brings max speed to 140 rpm and max torque to 12.35N.
Limitations/Requirements:
- Single phase AC 230V. Lack of 3 phase supply in the mixing area. This was one of the reasons my predecessor bought the Universal AC/DC motors.
Understand that some VFDs accept single phase inputs and can still drive 3 phase motors.
- RPM control must be by a rotary knob/pot know as frequent changes are required – push button may not be durable in the long term.
I was considering the 186rpm/16Nm/0.37Kw (Box040) here http://www.rotomotive.com/tabelle_prestazionali_02.pdf
Now comes the difficult part – I have never bought a VFD – ever and haven’t the faintest idea on spec-ing those!
After reading on the web, I was able to gather that a sensor less Vector drive will maintain torque along the spectrum of speed and not cause severe torque issues at low rpm (we tend to run the drives along all rpm bands depending on thickness and quantity of the fluid).
Any help in this area will be appreciated.
I will be sourcing locally from India but I may be guided using AutomationDirect as a benchmark.
Thanks in advance.
Amit SETH
Xsailor