Figure 350.3
Figure 350.4 - Clamp Bars Open
SECTION 360-PRECOATING OF FILTERS
In applications where the dust concentration is high and/or the dust particles are large (more than 0.5
microns), pre-coating of the filters is not required. In applications where the dust concentration is low
and/or the dust particles are small (less than 0.5 microns), pre-coating will result in a higher initial
efficiency and extended filter life. Maximum efficiency of the filter is not achieved until a dust cake is
formed on the media, which may take weeks without pre-coating. By applying a suitable pre-coat dust,
maximum efficiency can be attained in a few hours. This is desirable if the air is to be re-circulated
through Safety Monitoring Filters (SMF), or if the dust is toxic. Also, if the collected dust contains a
considerable content of hydrocarbons or similar substances, the life of the filters can be greatly increased
by pre-coating.
Pre-coating Procedure
1. Ensure the filter cartridges are correctly installed.
2. Install a clean, empty discharge container under the unit.
3. If a Safety Monitoring Filter (SMF) is installed, it must first be removed from the system.
4. Disable the dust collector so that it does not pulse while the pre-coat is being applied. This can be
done by shutting off the compressed air and bleeding the compressed air reservoir or turning off the
power to the timer control.
5. Weigh out the appropriate amount of pre-coat dust according to Table 360.1.1.
6. Start the collector and feed the pre-coat dust into the collector. The dust can be fed into any suction
hood in the duct system or through the hopper discharge.
7. Dust will be observed from the fan outlet. This is normal and should stop when all the pre-coat dust
is applied.
8. When all the dust has been applied, collect the dust from the discharge container and repeat the
above procedure.
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