SMOKE AND FLUIDS
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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
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.
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
Water based smokes are dense and white, and the generators
that produce them, such as our Colt, can be simple to operate and
Typically two-thirds of the 'Smoke Chemical' is made
up of active ingredient, the remaining one-third being purified,
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
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.
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
Concept do not compromise on quality or safety.
They have been producing artificial
smoke systems since 1962, and have
a comprehensive technical library of health and safety reports, analyses,
independent laboratory tests and particle distribution data second
to none. The smoke
produced by their systems is amongst the safest available today.
Indeed, Concept are the only
generator specialist to currently hold BS EN ISO 9001 Quality Assurance
Approval for the "Design and manufacture of NON TOXIC smoke
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
be they water or oil based.
The general benefits of producing such a consistent
and clearly defined particle distribution are:
Concept's expertise in the field means that they
actually produce systems specifically designed to fulfil the requirements
of BS 5295, for the testing of HEPA filters in the nuclear, chemical
and pharmaceutical industries Concept also have personnel registered
with the National Radiological Protection Board (NRPB) for site work
at nuclear establishments.
- 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
- 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
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
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
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
Pea Soup Ltd. stock the full range of smoke machines,
fluids and accessories from Concept. We are the number one worldwide
distributor of Concept products.
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||A small robust smoke generator for portable high output smoke generation.
|Colt 4 Turbo
||A small robust smoke generator whose physcial size belies its power. Twice the power of the Colt 4.
||Continuous high output quality machine.
||Oil-based smoke machine for large applications whose smoke has a high temperature tolerance.
|Mini Colt 4
||A smaller compact version of the Colt 4 smoke generator.
|Concept Smoke Fluid
||All types of Concept smoke fluid for this smoke machine.