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USER SECTION
CHAPTER 1 – BASIC PRODUCT INFORMATION
CHAPTER 1
BASIC PRODUCT INFORMATION
Ductless fume cabinets provide operator protection by removing chemical fume contaminants within the
work area. They are suitable for most common chemical work (Note that ductless fume cabinets are
NOT suitable for all chemical application. Please consult Esco for advice concerning your individual
application). The Esco Ascent Opti Basic/Ascent Opti Ductless Fume Cabinets are our new-improved
products which offer the best combination of performance, quality and cost-effective in the market today.
1.1 BACKGROUND
Conventional ducted fume hoods provide safety to laboratory personnel by drawing air across a front
opening in the hood at a controlled rate, thus preventing any toxic vapours generated during the
experimental procedure from escaping into the general laboratory environment.
Air is then exhausted via a fan system to the outside of the laboratory, usually via an outlet mounted on
the roof of the building. When released to the external atmosphere in this manner, chemical fumes and
vapours, which would have otherwise been toxic in the enclosed environment of the laboratory, are
diluted many times over and have an insignificant effect on the environment.
Ductless fume cabinets are quickly becoming a viable alternative to conventional fume hoods. Unlike
conventional fume hoods, these cabinets filter out chemical fumes and recycle air directly back to the
laboratory. Personnel protection is provided in a manner similar to conventional fume hoods by drawing
air at a controlled rate across a front opening into the hood. Ductless fume cabinet has many advantages
over conventional fume hoods:
•
They protect the environment since toxic fumes are not released to the environment unlike in the
conventional fume hoods.
•
Fully installed systems ready to operate are available at a lower cost than bulky conventional
fume hoods.
•
An expensive ducting and external blower system that is often difficult to maintain is not
required.
•
They are mobile and can be relocated easily to meet your changing needs; perfect for schools
and education institutes.
•
They allow energy saving since air which is costly to air condition or heat is not removed from
the laboratory.
In order to gain a better understanding of their benefits, let us examine how these hoods filter out
chemical fumes generated during experimental procedures conducted in the laboratory. Esco’s ductless
fume cabinet incorporate a state-of-the-art vapour phase activated carbon filter system, which is the
primary filtration component in removing all chemical fumes from within the hood before air is re-
circulated back to the laboratory.
Activated carbon is a porous material manufactured from carbon-based raw materials. These include
coal, peat, coconut and wood. The activated process develops pores of molecular dimension within the
carbon particles. These give the carbon an extremely high internal porosity and surface areas. Typically,
activated carbons contain surface area in the range of 500-2000 m
2
/g.
The basic mechanism through which activated carbon removes impurities from contaminated air
saturated with chemical fumes is referred to as physical adsorption. Physical adsorption is a
phenomenon resulting from electrostatic forces of attraction (van der Waal forces) between the impurities
and the internal surfaces of the activated carbon. Activated carbon has the strongest physical adsorption
forces or the highest volume of adsorbing porosity of any material known to mankind.
The safety of personnel in the laboratory has always been of significant importance. Similarly it is
important to consider the factors affecting the efficiency of activated carbon filtration in order to ascertain
the ability of the technology to provide a safe solution in the laboratory.
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Summary of Contents for ASCENT OPTI BASIC
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