Customer A has seven separate fermentation rooms using open top vats for fermentation of their traditional beer.
Six of the rooms are within a close proximity to each other and therefore can be covered by one gas sampling system, whereas the other fermentation room is in a different location requiring its own sampling system.
After carrying out a site survey it was recommended that each room would require six sampling points to give adequate coverage.
The systems used for this application are the GDS305 sampling system covering six rooms with a total of 36 sampling points, whereas the remaining room is covered by a GDS306 sampling system with 6 sampling points.
Due to the use of a dual head sample pump, the GDS305 draws a sample from all points constantly thus giving a very quick sample time of between 15 – 30 seconds per sample. Each room is sampled sequentially meaning that it is tested once every 1.5 – 3 minutes. Due to the size of the rooms covered this was deemed to be adequate coverage due to the relatively slow build up of gas spilling over the vats and the level of alarm which operates the ventilation – (if a quicker response was required then the alternative would have been to locate detectors in place of the sample points – this is considerably more costly).
Each system is connected to the specific area ventilation system that is activated when the level of Carbon Dioxide (CO2) rises above 0.5%. Once the gas level reduces to below the 0.5% threshold the ventilation fans are on an overrun timer of 15 minutes to ensure that the gas has fully cleared.
Each system is also connected to an audible visual device that operates should the level of Carbon Dioxide (CO2) rise above 1.5%.
Brewery Gas Detection - Case Study
Sensors for Safety Ltd gas detection equipment used in construction management procurement.
The brewing of beer is a century's old tradition steeped in malted barley, hops, water, fermentation and special ingredients.
Gas hazards in a modern brewery consist of Carbon Dioxide from fermentation, CO2 recovery and carbonation processes, Disinfectants for cleaning, water purification or waste stream treatment and sterilisation, Ammonia leaks from refrigeration, and gases which are by-products of waste treatment such as Hydrogen Sulphide and Methane, plus the potential for Oxygen deficiency in certain areas.
Carbon dioxide (CO2) gives the fizz to soft drinks and the head on beer. In breweries CO2 is recovered from fermentation and used for carbonation. High concentrations of CO2 are toxic and can cause Asphyxiation. Above 1,000 PPM (0.1%) CO2 causes drowsiness. Caution: CO2 is heavier than air and cellar or low lying and enclosed areas may be hazardous.
|Name (Formula)||Alarm 1||Alarm 2||TWA (8 Hr)||STEL (15 Min)|
|Carbon Dioxide (CO2)||0.50%||1.50%||0.5%||1.5%|
|Chlorine Dioxide (CLO2)||0.10ppm||0.30ppm||0.10ppm||0.30ppm|
|Methane (CH4)||20% lel||40% lel|
|Hydrogen Sulphide (H2S)||5ppm||10ppm||5ppm||10ppm|
Pure water suitable for brewery use can have a combination of settling, aeration, coagulation, filtration, and sterilisation treatments. Ozone or Chlorine may be used in treatment and these must be monitored at the storage or generation and injection points.
Process Equipment Cleaning often utilises sterilisation chemicals or gases which are stored in tanks or cylinders with metering or injection pumps. Such an equipment area needs to be treated like confined space with permanent gas monitoring equipment and annunciation.
Brewery wastewater has a high organic content. To minimise the potential impact that it can have on a municipal wastewater treatment system, anaerobic digestion is increasingly being used. This process generates Biogas and allows recovering solids for land application. The Gas may also be recovered and used for steam generation. Water is often re-processed for irrigation and other uses, reducing effluent.
Biogas consists mainly of Methane, CO2 and H2S. The presence of Methane means that the area may be classified as a hazardous area.