Servomex Marino Müller AG Multiplex CO2 O2 Gas Analysis System
Gas Analysis System for the Measurement of O2 and CO2 of a group of biotechnology fermenters / bioreactors:
We offer an industrial mature analysis cabinet initially commissioned January 2017, housing a Servomex Servotough 1910 Oxy Analyser and one Servomex 2500 Infrared Analyser, for CO2 with suitable sample preparation as discussed below.
In view of the accuracy and stability requirements, a “wet” system is proposed which would measure the fermenter headspace conditions without first removing one sample constituent - water. Since the water content is not precisely known, removal of water changes the gas composition considerably and not always in a predictable manner. Therefore a wet system is used: the sample gas is ducted to the analyser cabinet by a heat traced line, and kept at a temperature well above the dew point (assumed to be 40°C) until after the gas has passed through the analysers. The oxygen analyser is heated to 60°C, the infrared analysers have a heated sample cell which can be heated to any temperature between 30 and 130°C.
Fermenters and Analysis Equipment will be installed inside a building, and therefore be protected from extremes of temperature, rain and sunshine. The installation site is classified as a non-hazardous area.
Electric energy need is at 230/400V 50 Hz. Calibration Gases will be available from cylinders.
The sample gas coming from the fermenters is mainly composed of air / oxygen and Carbon dioxide. Oxygen and CO2 shall be measured. Other gases are not present in concentrations likely to interfere with the O2 and CO2 measurement.
The sample gas is available at the end of a heated line from the fermenter, after a sterile filter. The gas is available at a pressure of approx 200 hPa, so a pump will not be required. The gas will be saturated with water vapour at the operating temperature of
the fermenters, which is about 40°C. Dust loading of the gas is expected to be minimal.
Output signals are provided for the O2 and CO2 levels as 4 ... 20 mA analogue signals. These shall generally be scaled as follows:
0...25 % O2 4 ... 20 mA, 0...10 % CO2 4 ... 20 mA.
In the case of the oxygen measurement, the measurement range is user selectable and a suppressed zero may be desirable, i.e 16 ... 21% O2.
The analysis equipment can be controlled by common automation equipment, such as digital switches, provided by the operator. This will govern which fermenters are measured when, what dwell times shall be applied, sequence of measurements etc. The analysis equipment shall provide the necessary control interfaces. The analysis equipment shall provide
measurements of high accuracy and long- term stability.
A manual override is provided to control reactor assignment, for test purposes or backup of an automatic system. LED’s, on the terminal strip will indicate the activated solenoid valves.