Oxygen monitoring in silo's and bins to prevent dust explosion

Oxygen Monitoring used in inert systems for f.i. chemical powder storage and transport 

The atmosphere in the silo or bin is inertisized with N₂ with the result that due to the low oxygen concentration no explosion can occur. To ensure that the oxygen concentration is maintained within the specified limits it is necessary to monitor and control the N₂-dosing process.

Since the environment is mostly very dusty it is not advisable to use a sampling system with a pump. The dust will frequently block the tubing and filters of the sampling system causing a high level of maintenance. The Steuma Monox1000 operates with the diffusion principle. The monitor is mounted on a flange which is located at the top of the silo or bin. The gas in the atmosphere of the silo diffuses into the oxygen sensor. Since there is no positive movement of chemical powder to the sensor the sampling gas will not block filters and tubing. The right design and choice of components ensures a long term maintenance free operation. 

Monox1000 instrument features:

• There is no necessity of gas sampling.
• Low maintenance, no blocked filters, no tubing, long sensor life.
• 4...20 mA, 2 wire Oxygen Transmitter with digital display.
• proven to be reliable in this application for over 15 years!
  

The Monox 1000 is intrinsically safe and is a 4..20 mA transmitter type instrument with digital display for the measured concentration. The sensor is built in an pressure proof stainless steel housing provided with a teflon filter. The transmitter housing is made out of aluminium, is waterproof and RF-shielded.

Intrinsic safety is tested according to EEx II C T4 with certificate number ISSeP 99E.101.246. 

Customers: 

Steuma delivered hundreds of units to Sabic Innovative Plastics plants through over the world. Other customers are Momentive Performance Materials Silicones (Bayer) and INEOS Nova Breda.

Recently Hexion Pernis Rotterdam NL installed a couple of units in an inertisized truck loading system for chemical powder.

See for more detailed information on the Monox1000 Oxygen Monitor in chapter "products" » "gas analysers"

download: Application Note: monox-inert-01