Succ

ess

Stor

yReliable and Cost Efficient Monitoring

of Process Off-Gases

The oxygen gas measurement system from METTLER TOLEDO is an effective tool in explosion prevention procedures as employed by WACKER at its produc-tion site in Burghausen, Germany. This inline measurement substantially redu-ces maintenance costs and offers real-time monitoring of process off-gases.

INGOLDLeading Process Analytics

whole, and the largest chemical comp-lex in Bavaria. At this over two squarekilometer site, some one thousand dif-ferent products are produced by roughly10,000 employees divided among 150different production plants. The spect-rum of products ranges from polysiliconand hyperpure silicon wafers over sili-cones, silanes and silicic acids throughto dispersions, redispersible powders,solid resins, paint resins, fine chemi-cals and biotechnological products.

Wacker Chemie AG, Burghausen, GermanyBurghausen lies in the district of UpperBavaria, 110 km east of Munich, closeto the border with Austria. The town ischaracterized by the longest reach ofcastle compounds in Europe, its me-dieval quarter, and above all by theWACKER chemical plant site. The works established there in 1914 aretoday the most important productionfacilities of the WACKER Group as a

Direct oxygen measurement in the waste-gas manifold.

2 METTLER TOLEDO Success Story

O2

Gas

Mea

sure

men

tBusiness Division SILICONESWACKER SILICONES ranks among thelargest silane and silicon producers in the world. Highly differentiated pro-perties make silicone ideal for a largenumber of applications. In the sector“Functional Silicones and Oils”, underthe management of Corinna Müller,about 75 employees are engaged chief-ly in the manufacture of preliminaryproducts for e.g. the automobile indus-try, building materials protection sector,and cosmetics industry.

Comprehensive safety design Safety is a top priority at all WACKERsites. Thanks to a comprehensive safetyprogram, the accident rate lies well be-low the average for this industry. Part of the safety program is an effectiveinertisation strategy for (process) off-gases, i.e. ensuring an oxygen-freewaste-gas discharge system. To ensurethat the waste-gas stream is totally oxy-gen-free in terms of active explosionprevention, the “Functional Siliconesand Oils” plant employs oxygen mea-surement technology from METTLERTOLEDO. The safety program stipulatesthat oxygen concentration in the waste-gas stream must be below 5 vol. % O2.If this limit is ever exceeded, proceduresare immediately triggered to ensure thatsafety is preserved at all times.

Normally, the concentration of O2 mea-sured in the waste-gas is below 0.3vol. % O2. The waste-gas stream ismade up mainly of nitrogen, silanesand hydrocarbons. Traces of other ga-ses may also be present, dependingupon the process in operation. Thewaste-gas has a temperature of appro-ximately 20 °C (68 °F) and 50 – 100mbar overpressure.

Direct installation in the waste-gas manifoldWACKER chose to use METTLERTOLEDO oxygen measurement tech-nology because sensor design alloweddirect insertion into the waste-gasmanifold without the need for a costlysample gas conditioning system withhigh-maintenance requirement. Easyhandling, robust design and low-maintenance components are the keyfactors best describing the oxygen sen-sor InPro 6800 Gas. Calibration of thesensor is carried out directly in air, andtakes only five minutes.

Oxygen measurement systemThe complete oxygen measurementsystem consists of an oxygen sensorInPro 6800 Gas, retractable housingInTrac 777e, and modular high-perfor-mance transmitter M 700 XC. All com-ponents are certified to ATEX standardsEX II 1/2GD EEx ia IIC T6/T5/T4/T3,and labeled accordingly. They aretherefore also suitable for use in aninflammable dust environment.

InTrac retractable housings allow sen-sor maintenance in-situ without havingto interrupt the ongoing process. Forinstance, the sensor can be calibratedor checked in air or other gas directly inthe flushing chamber of the housingwithout removal. The modular high-per-formance transmitter M 700 providesvery precise measurement readings.The unique “Plug & Play“ design andmodularity of the system offer flexiblesolutions that can be attuned exactly tothe individual measuring task.

www.mt.com/proVisit for more information

Replacement for paramagneticsystems reduced costsOxygen measurement technology fromMETTLER TOLEDO has now replacedthe paramagnetic systems formerlyused for monitoring the waste-gasstream. Maintenance effort had beenconsiderable, since very often traces ofoils and other substances caused da-mage to the sensitive measurement de-vices, calling for frequent cleaning and repair work. The METTLER TOLEDOmeasurement technology met WAC-KER's extensive needs due to easy

handling and the possibility of installingthe sensor directly into the waste-gasstream without having to condition thegas prior to measurement. “Thereforethe costs arising from the complexsample gas conditioning now no longerapply, and overall maintenance costshave been reduced quite substantially”,stated plant engineer Markus Krämer.

In 2006, a further three points will beconverted to take METTLER TOLEDOoxygen measurement equipment.

O2

Gas

Mea

sure

men

t

Mettler-Toledo AGProcess AnalyticsIm Hackacker 15CH-8902 UrdorfSwitzerland – 07 / 06