Failure (Error # AL.03) in a EJA-110 DP tansmitter (Yokogawa) used as a boiler¦s drum level sensor

[lcms]

Dear Sirs,

The company where I work (rubber production industry) as a Process Engineer has two Alfa Laval Boilers MP-6.5 (6.500 kg/h)for saturated steam 170# generation fully automated with Yokogawa instrumentation, including FF communication platform. This steam generation area has been working for more than six months and since then three boiler drum DP level sensors (Yokogawa model EJA-110 have already broken down (permanent failure code ERR AL.02 and AL.03, CPU burned) in both boilers (two in Boiler tag A and one in boiler tag B). Each boiler has two different approaches for level control, and the DP sensor is used on the most advanced one (3 points level control, including flow and pressure trim). Now we are using the old fashioned level control based upon three electrode switches (ON-OFF control), and this is impairing our boilers performance (efficiency and pressure variation).

I would really appreciate if one of you guys has any clue, or even better, a previous experience in what might be happening that could cause so many failures. Another important information: - the technology of this kind of sensor are the resonance silicon and the sensor that was first installed in the same column of blown down valves were relocated to a different location to avoid vibration that were causing another alarm (ERR AL.02) that changed his status to MANUAL OVERRIDE and obliged us to disconnect and reconnect it to return it to AUTOMATIC MODE.

Thanks in advance,

LCMS.

 

[GHartmann]

Unless these level transmitters have some type of water leg or seal I believe you will overtemperature them with the steam in the boiler drum. A good boiler designer/supplier should know that. If you have relocated the transmitter you could have compromised the water leg installation. You should also contact your local Yokogowa rep regarding the error message.

Google the web for "boiler drum level transmitters". The pictures that show up will illustrate the water leg concept.

Good luck.