Use In Biogas Plants; Preparation For Commissioning; Leaks In The Gas Paths - Siemens ULTRAMAT 23 Series Equipment Manual

Commissioning

6.2 Preparation for commissioning

6.1.3

Use in biogas plants

Danger of poisoning
This device is designed to measure hydrogen sulfide and dihydrogen sulfide, H
Hydrogen sulfide is highly toxic even in small concentrations! The odor threshold for hydrogen
sulfide is very low at 0.02 vpm (20 vpb), but higher concentrations result in numbing of the
olfactory receptors in the nose so that the odor is no longer perceived. Persons exposed to this
gas in concentrations up to 100 vpm for several hours exhibit symptoms of poisoning such as
fatigue, headaches, lack of appetite, lack of concentration, irritation of the mucous
membranes of eyes and respiratory tract, and throat irritations.
Inhalation of H
Concentrations above 1 000 vpm cause death within a few minutes, concentrations above
5 000 vpm cause death within a few seconds!
When using this device in plant where there may be high concentrations of H
therefore need to take following continual precautions to prevent the effects of poisoning:
• Connect the gas outlet of the analyzer to a gas exhaust unit so that no gas can escape into
• Before you begin maintenance on the analyzer, make sure that the H
• Check for leaks in the analyzer at regular intervals!
Danger of explosion
This device is used in biogas plants, among other places. When it is used in biogas plants, you
should expect that the sample gas will contain methane, which forms explosive mixtures with
oxygen or air in certain concentrations. These conditions are possible with certain operating
states of the plant.
6.2 Preparation for commissioning
6.2.1

Leaks in the gas paths

Checking for leaks is most easily performed by connecting a U-tube manometer to the sample
gas inlet. You can check for leaks as follows:
1. Block the sample gas outlet
2. Create an overpressure of around 150 hPa (rel.) at the sample gas inlet.
3. Wait for about 60 seconds for the temperature of the incoming gas to be compensated.
80
DANGER
S concentrations of 500 vpm longer than 30 minutes can cause fatal poisoning.
2
the environment!
analyzer is close to 0 vpm. Before beginning work, always flush the gas path of the analyzer
and the gas sampler with ambient air or nitrogen for a duration of about 10 minutes .
DANGER
2
S concentration in the
2
Equipment Manual, 04/2022, A5E37100388-012
S)!
2
S and you
ULTRAMAT 23