GAYLORD RSPC-ESP-OW Series, Техническое руководство

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___________________________________________________________Chapter 1 – Introduction, Page 1-3
Introduction (Cont.)
Other more technical methods of determining opacity or particulate density are achieved through the
use of opacity meters and cascade impactors. This level of analysis is usually referred to as source
testing. Control agencies occasionally require this type of analysis and if so, the testing is conducted by
state certified contractors which can be quite costly and time-consuming. The efficiency of a pollution
control unit is based on how well it reduces the opacity level of a given airstream. The Gaylord ClearAir
unit will reduce the opacity level below 20%, thereby meeting the requirements of environmental control
agencies.
Basic Facts About Odor
Cooking odors (molecules) generated by the combustion of animal and vegetable matter result in an
extremely complex mixture of reactive organic gases (ROG’s). A small percentage of these odors may be
absorbed by the grease particles but the vast majority exists separately in the airstream. The ROG molecules
are much too small to be removed by any type of filter and therefore, other methods must be used. There
are several methods with which to manage the odor. One method is to use a media bed. The three most popular
types of media bed are activated charcoal, which absorbs and retains the odor molecules, the use of an odor-
oxidant media (potassium permanganate) which oxidizes the molecules to solids and then retains them, and
a blend of the two. Another method involves the use of a liquid delivered with a finely atomized spray. This
spray performs a similar function to potassium permanganate in that it adsorbs or chemically neutralizes
odors. This process has the benefit of the end user being able to adjust the amount of spray and thus the
effectiveness and cost of the odor control.
The life of the media bed type of odor control is dependent upon several factors such as how much media is
used, type of odor, amount of odor molecules, grease loading and air temperature. Typically, any of the
above mentioned types of media can remove 85% - 90% of the molecules. Determining the efficiency of odor
control can be very subjective, as testing is usually conducted by the human nose. More scientific testing is
available through ROG analysis, but this involves considerable costs.
Grease Removal - The Important First Step
Grease particles are also measured in terms of microns and grease generated by commercial cooking
equipment has a particulate size of 0.1 microns and up. Pollution control equipment is not limited to removing
smoke particles, but will also remove a majority of the grease particles remaining in the airstream.
Therefore, the grease extraction efficiency of the exhaust hood plays an important role in the operation and
performance of pollution control equipment.
Removal of grease particles before they reach smoke and odor control equipment will significantly
increase the smoke abatement efficiency and the life of the odor abatement media.