How to Select a Valve

Thanks

What is the duty cycle? How often will you need to open/close the valve?

You may also consider augur feeders.

http://www.augerfeeders.com/

http://process-equipment.globalspec.com/Industrial-Directory/auger_feeder

bioramani

Not the most precise method certainly, but another option would be a simple butterfly valve (very common and economical in 8" size). You could then couple it up with an actuator of your choice, pneumatic, electric, etc.

The butterfly valve will wear with this material over time, but you can simply replace or rebuild the valve as needed depending upon the duty cycle.

Pl. use two position gate valve. This two position will be achieved by sesors mounted on valve. At initial position, valve is full open. so that there will be coarse feeding of the material. After feeding 20 Kg. or more the valve get half/partially closed, so that fine feeding start. After 25 Kf. the valve is fully closed. For this operation, get signal from load cell. This is called two set point of the load cell.

Sanjeev Unawane

"use two position gate valve" And what about all the other variations in between full open and full closed??? You did mention half/partially closed, is that not a position?

Gate valves are not really intended to throttle fluids or solids and this material might make it difficult for the valve to close.

Thats a very heavy and expensive valve as well

the sensor defines middle position of the valve i.e. betwen open and close postion. this is for fine feeding of the material.The material falls due to gravity. The gate valve genarally operated by pneumatic cylider. The gate valve is not costly as compared to other type of valve.

For an application such us this I would recommend soft seated butterfly valves, though I have never been involved with Zinc Oxide per se. One type that shows good results is this or similar inflatable seat type butterfly valve. (Usual disclaimers).