Civil Engineering Reference
In-Depth Information
Fig. 24-13b.
Gravimetric feeder (Courtesy of Infilco Degremont, Inc.)
lumps and undissolved particles. Most feeders, regardless of type, discharge their ma-
terial to a small dissolving tank that is equipped with a nozzle system and / or me-
chanical agitator, depending on the solubility of the chemical being fed. It is important
that the surface of each particle become completely wetted before entering the feed
tank to ensure complete dispersal and to avoid clumping, settling, or floating.
A dissolver for a dry chemical feeder is unlike a chemical feeder, which by simple
adjustment and change of speed can vary its output tenfold. The dissolver must be
designed for the job to be done. A dissolver suitable for a rate of 10 lb / hour (4.54
kg / h) may not be suitable for dissolving at a rate of 100 lb / hour (45.4 kg / h).
The capacity of a dissolver is based on detention time, which is directly related to
the wettability or rate of solution of the chemical. Therefore, the dissolver must be
SCALE
BEAM
HOPPER
CONTROL WEDGE
SLIDE
GATE
VIBRATOR
VARISPEED
TRANSMISSION
ENDLESS
BELT
Fig. 24-14.
Rigid belt gravimetric feeder (
Source:
Reference 7)
