New Version Of Drum Roaster

Introduction :

Principle :
  An eccentric, flexible parabolic reflector which rotates around an axis parallel to earth-axis, synchronous with the sun. Additionally, the reflector is adjusted to the seasons by flexing it in a simple way.

what is scheffler :

Heat form sun rays can be harnessed to provide heat to a variety of Application ,but in general , sun’s rays are too diffuse to be of direct use in Those applications.

common application of scheffler :

  1. Boiler feed water preheating
  2. Washing in laundries
  3. Oil heating for cooking purpose
  4. Milk pasteurization
  5. Steam cooking
  6. Oil heating for industrial application

        working of scheffler :    

  • The parabolic reflective dish turns north – south axis parallel to earths Axis ,tracking the the suns movement from moving east to evening est Maintaining gravitational equilibrium to the dish.
  • The parabolic reflector also performance change in inclination angle While staying directed to sun in order obtain sharp focal point.
  • focal lies at the axis of rotation. it remains at a fixed position ,where Concentrated heat is captured and transferred to roaster drum Surface through reservoir to generated heat.
  • The surface roaster is heated and its continuously rotate that time Internal subject will heat or in water heating system water form Heater pipe passes to reservoir thermosyphon principle.                                                                                                                  


Roasting is a cooking method that uses dry heat where hot surface envelops The food, cooking it evenly on all sides with temperatures of at least 150 °C From surface heating using solar heating or other heat sources.

Roasting Can enhance through solar heating on the surface of the food. Roasting uses Indirect, diffused heat (as in an oven), and is suitable for slower cooking of Meat in a larger, whole piece.

Problem Statement :

In the previous version of drum roster are two major problem identify

1 . Epoxy food paint those painting inside the drum was melted and mix with food.

2. The temperature lag between inside (110^ C ) and outside temperature (210 ^C ) of drum roaster was more 100^ C .

3. Uneven roasting of food

DISCUSSION : Discussion topics

1.Design and fabrication : In the design discussion there was two things Cum out . first one is made angular section part in middle portion of the the Drum roaster, second one replace the external M.S sheet surface.

2. Material selection and thermal properties materials : we selects the ” General aluminium type” materials .

Aluminium thermal properties

A. Soft ,highly ductile wrapping foil, malting point of aluminium is 500 C (1200 F) and MS metal melting point 1510 C (2570 f).

B .Density of aluminium 2.7 gm per cm sq , appro. one third as much as steel 7.83 gm per cm sq.

c. Permit design and construction of strong light weight structure.

3. Baffles for proper mixing :

Another problem occurs in drum roaster was Uneven heating. the problem made due to heating surface area of drum roaster was more than the frontal projected area of scheffler solar heating area . due to we deside use baffles for proper mixing and concentrated towards heated surface of drum roaster.

fig . scheffler adjustment….with Amol and Prasad

fig . experiment of aluminium thermal expansion…
fig . Previous version

previous version specification :

dia. of drum = 600 mm

length of drum =700 mm

drum material =mild steel

Cutting central 550 mm portion of the drum roaster ,and remaining 150mm part are include basic structure.

fig . After cutting central portion.

fig. remove epoxy paints
  • After completing work this work , start the fabrication of drum roster joining drum with aluminium sheet by using of reveted joint.
fig. solid work design

fig . fabrication of drum roster

Baffles Fabrication :

  • First baffle make by MS sheet metals thickness 1 mm.sheet metal bend by using sheet Metals bending machine.
  • Then sheet bending angular way by using hammer and one side of Metal sheet cut triangular shape .
  • But the external surface of baffles was not alignment with the Aluminium sheet surface, due to its not joint properly with Aluminium.
fig. MS sheet baffles..
  • Second baffle make by MS sheet metals ( 3mm*50mm) plate . corners was cut by 45 degree , but problem are those are very small.
fig. ms sheet metal
  • Fig. MS Plate sheet (3mm*50mm)
fig . final baffles…

Third baffle make 1mm sheet metal .

Finally thermal absorbent paint are painted on external sheet of aluminium.

fig.Thermal absorbent Painting of drum roster.
  • fig . installation of drum roster
fig .solid work design