| Author | Pandey, Ram Krishna |
| Call Number | AIT Thesis no.AE-80-03 |
| Subject(s) | Grain--Milling
|
| Note | A thesis submitted in partial fulfilment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Abstract | In this study, the breakage of soybean and wheat was analyzed in a simple laboratory type hammer mill in terms of the specific rate of breakage and breakage distribution parameters. A rectangular steel bar was used as a hammer. The mill was operated with an A.G., one hp motor with suitable. belt and pulley arrangement to vary the speed of rotation. The short duration batch grinding tests were performed using a blind screen 16.2 cm in diameter and 5.1 cm long to determine the $pecific rate of breakage and breakage distribution parameters. The effects of
grain size, moisture content, and the mill speed on specific rate of
breakage and breakage distribution parameters were evaluated for wheat and the soybean. In addition, the effect of mill loading on the specific
rate of breakage was determined. The experimental results showed that the breakage of whole soybean
and wheat and their broken fragments ยท in a laboratory hammer mill followed a first order law. The specific rate of breakage of soybean and wheat
was determined to be a power function of the particle size in each case. A good correlation was observed between the specific rate of breakage and
mill operation variables and the condition of the grains. Wheat and soybean exhibited non-normalized breakage distribution parameters which
were not apparently influenced by any change either in the grain moisture content or the mill speed. The non-normalized B-values were expressed in an equation form in order to extend their range of applicability
required in the subsequent computer simulation scheme.
The continuous grinding tests were performed for wheat grains (6.0% d.b.) of 3.35 x 2.36 mm size. For these tests, a steady feed rate into the grinding chamber was maintained by a vibratory feeder. The whole area around the periphery of the grinding chamber was covered by a screen having perforation of 3 mm diameter. The mill was run with a single hammer at 4450 rpm. The computed and experimental size distributions of final. product and the material in the mill were in close agreement. Some improvements
in the computed values of size distributions were observed by introducing the concept of a screen retention parameter. It was observed that the feed rates used in this study did not influence the size distributions of
the final product and the material-hold-up in the grinding chamber under identical operating conditions. The power required to operate the mill
increased with an increase in the amount of material present in the mill. Since the mill hold-up depends on the feed rate under any given operating conditions, it was possible to estimate the optimum capacity of the mill. |
| Year | 1980 |
| Type | Thesis |
| School | School of Environment, Resources, and Development |
| 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) | Jindal, Vinod Kumar |
| Examination Committee(s) | Singh, Gajendra ; Konaka, Toshio
|
| Scholarship Donor(s) | The Government of Australia |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1980 |