ABOUT CONCEPT SMOKE AND FLUIDS

Click to see the list

Pea Soup is the World's Leading Distributor
of Concept Smoke Generating Systems

Artificial smoke is produced by heating a chemical above its boiling point within a heat exchanger. The chemical is then vaporised, and it is when the vapour exits the heat exchanger and mixes with the relatively colder atmosphere that rapid condensation of the vapour takes place, resulting in a visible smoke (or technically fog).

It is important that the vaporisation of the chemical within the heat exchanger is complete, otherwise the production of a 'wet' smoke, or a smoke with a very large particle size will result.

Conversely, it is important that the heat exchanger through which the chemical is passed is not operating at too high a temperature, otherwise unpleasant and potentially hazardous pyrolysis products will be formed.

Water Based

The majority of smoke chemicals in use today are generally referred to as 'water based'. This rather vague term describes chemicals which are water miscible, and are in the main based on glycols and glycerol.

Water based smokes are dense and white, and the generators that produce them, such as our Colt, can be simple to operate and very compact.

Typically two-thirds of the 'Smoke Chemical' is made up of active ingredient, the remaining one-third being purified, de-ionised water.

Different Glycols produce smokes of differing persistencies, Propylene Glycol generally being the least persistent. Glycerol is by far and away the most persistent 'water based' smoke.

We would normally recommend that, where dense concentrations of water-based smoke are required (e.g. Fire Brigade Training, Leak Testing), that the most persistent smoke possible is produced (like our Colt 4 or Spirit 900A). The use of chemicals with high percentages of glycols, whilst producing dense white smoke, is not cost effective, as the smoke disperses so quickly that one is having to produce smoke almost all the time in order to keep up with the rate of breakdown of the smoke.

Glycol smokes begin to layer noticeably at 35-45°C, Glycerine smokes at about 50-60°C.

Oil Based

Concept also have over 30 years experience in the production of food quality oil based smoke systems. These systems produce a smoke that is far more persistent than the very best of the water based smokes, and so are capable of smoke logging huge volumes with relatively low consumption of smoke chemical. The smoke produced by the ViCount is also extremely resistant to very high temperatures, starting to layer at 135 - 180°C dependent on the viscosity of the oil chosen, making it highly suitable for hot fire training, as well as unheated applications.

How safe is artificial smoke?

Indeed, Concept are the only smoke generator specialist to currently hold BS EN ISO 9001 Quality Assurance Approval for the "Design and manufacture of NON TOXIC smoke systems".

Ducting

Smoke from all Concept systems can be ducted if required, using the inherent velocity of smoke produced by the systems, or incorporating fan assistance if rapid distribution of smoke is required.

Generally a small amount of deposition should be expected in ducting systems as the smoke particles are being artificially restricted, and cannot separate and spread out as they would in free air. For best results the ducting should be as short and straight as possible, with as smooth a bore as practical, so that frictional losses within the duct are kept to a minimum.

Fan assistance can greatly improve the effectiveness of ducted systems and Concept have a comprehensive range of centrifugal blowers to suit almost every application. If you have an application which calls for the ducting of smoke then please contact us. We would be pleased to assist you in specifying the correct ducting and fan combination, which we can also supply.

Particle Size - Why Small is Beautiful

Common to all Concept standard smoke generators is the incorporation of precision, machined, specially treated steel heat exchanger blocks, in which the smoke chemical is vaporised.

Conventional smoke generators normally use either cast or platen type aluminium heat exchangers, which, whilst very cost effective to make, generally produce a smoke particle with a mass median diameter (mmd) of 1 - 2 microns.

This compares with a typical particle size of just 0.2- 0.3 micron mmd for the vast majority of our Concept smoke systems, be they water or oil based.

The general benefits of producing such a consistent and clearly defined particle distribution are:

• the smaller the particle size of the smoke, (or more accurately fog) the smaller the amount of chemical is required within the atmosphere to achieve any given visibility. This can have a significant effect on running costs for heavy users of artificial smoke (fire brigades etc.)
• the less the amount of chemical in the atmosphere, the safer the smoke if measured in terms of relative Occupational Exposure Levels.
• the smaller the particle size of the smoke, the lower its settling velocity (the rate at which a particle will fall, due to gravity). A smoke particle of unit density, 0.2 micron in diameter, will fall at 9mm /hr, compared to a 2 micron particle, which falls at 468mm/hr. In essence this means that the smaller the particle of smoke you produce, the less chance there is that deposition of smoke particles will occur.
  
  

Temperature Resistance of Artificial Smoke

The artificial smoke produced by thermal smoke generators such as ours will break down as the ambient temperature increases.

Water based smoke s generally begin to layer at temperatures as low as 35°C, rising to around 60°C for Glycerine systems (such as our Colt 4 and Spirit 900A).

However, if smoke testing is required at higher temperatures, the ViCount range from Pea Soup Ltd. offers a practical and very cost effective solution. Resistant to temperatures up to 180°C before layering commences, the ViCount is rapidly proving to be a preferred choice for all applications, such as Hot Fire Training where the use of artificial smoke in elevated temperatures - previously limited to pyrotechnic smoke bombs - is required. Indeed, for some applications, customers have reported the smoke persisting to almost 200°C.

Concept have such expertise in the field of high temperature smoke systems that they were commissioned by the UK Ministry of Defence to project manage a range of comparative tests, held in controlled conditions, with the co-operation and assistance of the Department of the Environment, Fire Research Station, FRS Cardington, Atomic Energy Authority Harwell, and an eminent independent analytical laboratory.

Pea Soup work in partnership with Concept and are officially the number one distributor of Concept smoke systems worldwide, selling the entire range of Concept Smoke machines, including the Spirit 900, Colt 4 models and ViCount Compact systems. When high quality smoke and reliability are a neccessity, Concept from Pea Soup is the number one choice.

Click to see the list