Steam Drum Level Measurement

Any of these are workable:

Gamma-ray (say Cobalt) narrow beam from outside drum:

• Series of detectors fixed outside the other wall thru water level desired.Use YES-NO logic to determine
• One detector -ditto- kind of linear reception +SETPOINT
• One detector like above two- but near the transmitter-same wall-depend on gamma reflection from bubbles/impurites

Any of these are workable:

Gamma-ray (say Cobalt) narrow beam from outside drum:

• Series of detectors fixed outside the other wall thru water level desired.Use YES-NO logic to determine
• One detector -ditto- kind of linear reception +SETPOINT
• One detector like above two- but near the transmitter-same

I am pretty sure such arrangements are already commercialized

Magnetrol manufactures a guided wave radar level transmitter for steam that is rated to 165 bar. www.magnetrol.com

http://www.uk.endress.com/

Enderess offers Level switches for fixed points

for process temperatures of -50 °C to 150 °C

- for pressures up to 100 bar

Certainly no good for Supercritical steam Drum level.

And will need ONE fixed weldolet at each sensor. Cannot remove in sevice.

And you will need many sensors to get to know nearness to setpoints.

Does not serve the need.

Thanks for input.

Problem is temperature rating of suggested units - not suitable for 500C

Check out this guided radar liquid level sensor:

http://www.mohr-engineering.com/efp-guided-radar-liquid-level.php

It was originally designed for nuclear reactor heat exchangers, so it is probably fine for your boiler. The probes are good for long term exposure above 550 F in corrosive environments and the system measures the void-fraction / swell-height in boiling environments.