Process equipment / Level controllers and limiters
The regulations on the opeation of steam boiler units require the use of level limiters on steam boilers.
IGEMA offers both mechanical and electronic controllers / limiters up to pressures of PS = 200 bar.
Also self-controlling devices for steam boilers without constant supervision are in the program.
The quality of the boiler water can then be monitored and controlled by conductivity measurements in combination with valves for interval-off and blowdown valves with electrical actuators.
Due to the combination of a float with magnet rod in a guide tube, the level can be transmitted with the correspondingcontactors.
This BA or RBA float devices can be used as water level controller or limiter for steam generators to PS = 200bar.
Depending on the length there may be set to 1, 2, or several switching points.
A magnetic level indicator can only serve as a regulator.
Both discontinuous scheme with different magneticswitches and continuous control with corresponding PID controller whichcan generate a output signal 4-20 mA are possible.
Electronic systems consist of electrodes in combination with transmitters.
They make use of the electrical conductivity of the boiler water, and detecting whether the tip of the electrode pin is in the wateror the steam space.
The measurement takes place between the tip of the electrode and the wall of the measuring vessel or protective tube.
A distinction is made between low water (LW) and high water (HW) limiters.
LW limiters are in line with the European regulations, required for the safe operation of a boiler, HW limitation (overfill protection) is only required in accordance with TRD 604 for a 72–hour operation.