I am doing a project to automate our continuous blowdowns on our
115,000 lb/hr power boilers. Presently they have a variable orifice Hancock valve that the operator manually adjusts. I am wondering peoples opinions, on if I should put in a variable orifice automated valve (normal control valve) with PID control, or an open close valve (ball valve) with a restricting orifice and time proportional control.The control valve would be sized to give me 2% of feedwater flow at
50%, and the flow restrictor for the ball valve would be sized to give me 4% of feedwater flow.The ball valve with actuator is a cheaper solution, but is it better? The piping is 3/4".
Thanks.
Curtis