Analytical Procedures - Moisture in Gas Exit Drying Tower
February 24, 2002

Introduction Equipment Reagents Procedure

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Introduction

Moisture determination is performed on the drying tower outlet gas in order to check the drying efficiency of the tower itself.   In fact the presence of high quantity of water in the inlet gas to the converter, can be dangerous for the catalyst.

Moisture determination is carried out, in a fast and appropriate manner, making use of commercial selective glass vial, containing a special substance that changes its colour in presence of water.

This is a fast and easy way to perform this determination because the glass phial is already pre calibrated, directly, in mg of water absorbed.

Equipment

• Gas sampling chain (Probe, pump, flow meter etc.)
• Special glass vial for moisture (e.g. supplied by Dräger Tube)
• Hoffman clamps

Supplier                                     Dräger Sicherheitstechnik GmbH
Part No.                                     6728531

Range of Measurement             Test Volume
    2 to 80 mg/m³                          100 L
    5 to 250 mg/m³                           50 L
    10 to 450 mg/m³                         25 L
    40 to 1600 mg/m³                       10 L

Reagents

 

• None Required

Procedure

Fit about 1 meter rubber hose in a sampling probe, close the end with an Hoffman clamp. Set the probe into the sampling point and slowly open the clamp to purge for about 30 minutes with a flow rate of approximately 60 l/m (avoiding overheating of the rubber tube). Now insert the sample tube into the end of the rubber hose and make a sampling operation, during a period of time long enough to colour the vial.

The range of measurement and accuracy can be varied depending on the size of sample taken.  Refer to the information supplied with the Dräger tube for details.