Design, Development and Performance Evaluation of Fish Descaling Machine

Abstract

In fish post-harvest processing, one of the unit
operations involved is removal of fish scales which
is traditionally carried out by knife. The process is
time consuming and cumbersome. This may also
lead to injury to the person descaling the fishes. In
this context, a hand held fish descaling machine has
been designed and developed to increase the speed
of descaling process, reduce the drudgery and
improve the safety of operation. The fish descaling
machine has important components such as descaling
head, flexible shaft, safety shield, 1 hp motor, AC
drive and a stand for fixing motor and A.C. drive.
Four different types of innovative designs of
descaling heads namely, diamond shaped, inverted
V shaped, 13 slots and 26 slots were tested at
different speeds for the capacity, efficiency, energy
consumption and injuries inflicted. Performance of
the machine was tested for two fish species using
four descaling heads at 1440, 2000 and 2800 rpm.
The diamond shaped descaling head with its unique
design showed maximum descaling rate at 2800
rpm. The fish descaling machine reduced drudgery
in descaling operation and also reduced the time
required in descaling from 120 to 40 s for average
500 g fish vis a vis traditional hand tool in practice.
There were no incidence of injuries reported to
person descaling the fishes and also no skin
damages to fishes while descaling. Average energy
requirement was 0.25 kwh for the machine and an
unskilled labour was required for operation. The
machine is suitable for descaling of catla and silver
carp fish species.