Control of level and pressure in the same tank
The pressure control loop consists of; smart pressure transmitter, microprocessor based controller (only UV 400), I/P-converter and control valve, connected to the air supply. The pressurized tank is equipped with a safety valve, pressure indicator and a load valve with silencer. The level control loop consists of an smart differential pressure transmitter, microprocessor based controller (only UV 400), I/P-converter, control valve and pump. Pressure and level values are recorded on a electronic two pen recorder.
The two microprocessor based controllers have PID functions and may be configured for different types of alarm, limits control equations, set point ramp, linear or square root extraction of input signals and Auto tune, see separate pamphlet UDC 3200
Pressure and differential pressure transmitters have adjustable range and zero, giving a linear output of 4 – 20mA. The level has a three valve manifold for easy equalisation, calibration and dismounting during operation. Also the con- necting tubing between transmitter and tank can be filled during operation.
The control valves are equipped with single acting pneumatic actuators with air to close function.
The paperless recorder has 6 channels input 4 – 20mA.
All components are mounted on a industrial carriage with lockable wheels to give stability when in use.
The control models UV 200/201 or UV 210/211 can be connected in cascade with UV 400/401 and will then form a flow circuit connected to the level of UV 400/401. For this purpose the level controller is equipped with necessary connections and a switch.
– Configuration of controllers
– Calibration of electronic pressure transmitter
– Automatic control of pressure
– Optimization of control canstants with Pl-control of pressure
– Calibration of differential pressure transmitter mounted on a closed tank
– Control of level in a closed tank
– Optimization of control constants for control of level in a closed tank
– Control of pressure and level considering interactions between these media.
– Optimization of control variables
– Auto tuning during different operating conditions