| Author | Zhao, Xin |
| Call Number | AIT Thesis no. AE-92-11 |
| Subject(s) | Corn as feed
|
| Note | A thesis submitted in partial fulfillment of the requirements
for the degree of Master of Engineering, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Abstract | A lab scale horizontal double ribbon mixer with capacity
of 15 kg was developed to investigate the effect of particle
size on mixing operation for animal feed. Corn powder with
five different fineness of 0.002 (corn starch), 0 .429, 0.588,
0.698 and 1.139 mm and salt with fineness of 0.273 mm were
selected as carrier and tracer respectively. The experiment
was performed under five different agitator rotating speed,
i.e., 19.5, 30, 45, 60 and 80 rpm; and the mixing degree
expressed by coefficient of variation was separate l y detected
at 0.5, 1, 2, 3 and 6 min each time. The coefficient of variation of salt concentration in ten samples which were taken
from mixer at random position was determined by measuring
conductivity of sample solution. Moreover, two material flow
parameters, i.e . , angle of repose a nd angle of wall friction
were measured and applied to study the relationship between
flowability a nd mixing operation.
It was observed that convective and s h ear movement play a
major role during mixing processing in double ribbon mixer.
The experiment shows that particle size of materials and
agitator rotating speed have no significant effect on final
mixing degree within the fineness range of animal feed. The
mixing rate is obviously affected with alternation of fineness
and rotating speed . The higher mixing rate is achieved when
s mall fineness is applied. The high rotating speed is always
favorable for obtaining higher mixing rate. Particle size
distribution is expected to have important effect on mixing
rate. Particle size has significant effect on operating parameters. The optimum rotating speed ascend s with increasing of
fineness. At low speed (about 30 rpm), mixing time for both
" satisfactory mix" and "best mix" ascends obviously with
increasing of fineness. At higher speed, there is not
significant difference among mixing time wit h alternation of
rotating speed .
Moreover, The particle size has significant effect on
angle of repose a nd angle of wall friction. It was found that
good flowability of materials is not always necessary for
achieving satisfactory mix. The ability carrying tracer
particle is more important. |
| Year | 1992 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Agricultural and Food Engineering (AE) |
| Chairperson(s) | Athapol Noomhorm ; |
| Examination Committee(s) | Jindal, Vinod Kumar ;Illangantileke, Sarath G.
|
| Scholarship Donor(s) | United Kingdom; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1992 |