The setup consists of a process tank fitted with scale in which water enters through a Pneumatic control valve. Water is pumped to process tank from the sump tank by means of a centrifugal pump. The level transmitter is fitted in the process tank. The level of water in process tank is sensed by the transmitter and communicated to the digital indicating controller. This measured variable is compared with the Set Point by controller and output is generated and given to I/P converter, which in turn supply the 3-15 Psig pressure to vary the opening of the Pneumatic control valve to eliminate the error observed. As the opening of pneumatic control valve varies, the level in the Process Tank gets effected. This process goes on until the Set Point target is achieved. A ball valve is also provided in the process tank to disturb the system and to observe the effect of disturbance. The drain and overflow of the process tanks returns in the sump tank, hence the system operates in close circuit. These units along with necessary piping are supported in a well-designed housing and are fixed on base plate. The process parameter is controlled through Computer by micro-processor Controller (SCADA Model) by manipulating water flow to the process tank.
EXPERIMENTATION :