Ammonia Detection in Cooling & Refrigeration
Refrigeration is used throughout industry wherever there is a need to maintain a product or process at a defined level. Compressing a refrigerant gas and then allowing it to evaporate carries out this cooling process. Several gases can be used to perform this action, natural gases such as Ammonia and Carbon Dioxide or a manufactured range of gases known as Freons. For many years Freons (CFC’s and HCFC’s) were seen as ideal clean, non-toxic, odourless etc., however it was discovered that CFC’s cause depletion of the ozone level and are therefore banned. Their replacements, whilst causing less harm to the ozone layer, have a high global warming potential. In some cases, 100 times that of CO2. These gases are controlled by legislation known as F Gas regulations thus placing strict limits on the use of these gases and the necessity to detect them. You can find more information on this legislation in our F Gas compliance application note.
Ammonia has been used for over a century as refrigeration gas and has no global warming potential or effect on the ozone level. The drawback of Ammonia is that it is very toxic with a pungent odour and, in high concentrations, can be flammable. While this gas is not controlled by F Gas regulations, it is certainly subject to DSEAR regulations. You can find more information on these regulations in our DSEAR regulations application note. The main thrust of the DSEAR regulations is to control the use of dangerous substances and gases in the work place. Therefore, an automatic Ammonia detection system must be in place.
Typical market segments are as follows:
There are at least four different applications resulting from cooling and refrigeration with ammonia:
The GMI have a wide range of products specifically designed to meet and exceed all the requirements of the refrigeration industry. These systems have been designed to meet the vast range of different applications that are presented by using Ammonia as a refrigerant gas. The Active-8 and Active-80 range of controllers can be fitted with various types of Ammonia sensors dependent on range of detection required. These systems can also accommodate other sensors if required (CO2, Freons, Flammable Gases etc). In addition to these discreet sensor systems, GMI have a range of sampling systems that have been designed to meet the unique challenges of refrigerant applications including Ammonia. However, similar to the Active-8 / 80 range, these can also be fitted with other sensors for other gases that may be of interest. The larger of these systems (Seafarer) is capable of handling up to four gas sensors (Flammable, PPM Ammonia, Freons, CO2 depending on application). This system is capable of drawing samples from up to 32 points and by using a fast flow manifold thus cycle times are kept to a minimum.
The Seafarer will alert the operator if any of the pre-set alarm points are exceeded. The alphanumeric display clearly defines the nature and location of the problem enabling corrective action to be taken as quickly as possible. The system auto senses if a sample line becomes blocked and will try to clear it by using the optional blow back system if fitted, otherwise it raises an alarm.
Please note that although Ammonia is lighter than air and should rise to the ceiling in any facility, this will only occur if the gas is at the same temperature as the surrounding atmosphere. With refrigeration gas this may not be true, so gas temperature at a leak point should be considered.
Other useful information
GMI are more than happy to discuss with anyone their particular need for detection and will be able to propose the best system for your needs. This service is provided free and without any obligation, so please call +44(0)141 812 3211 and ask for the Fixed Systems Applications Team.
As an ISO 9001 approved company, GMI Ltd’s quality assurance programmes demand the continuous assessment and improvement of all GMI products. Information in this article could thus change without notification and does not constitute a product specification.
Please contact GMI or their representative if you require more details.