︎

Tomer Bromberg


Work


CRK Service Design
e4 Chess Set
Rice Cooker Redesign
Electric Wheelchair Trainer 
Design Inquiry and Repair

Bits and Bobs


Coffee Table
Glass Mobile
Film Photography

Rice Cooker Redesign


Year: Fall 2021
Location: Georgia Tech - Atlanta, GA
Purpose: Interactive CAD and CAE-ME 4042
Processes: Needfinding, CAD and FEA (Siemens NX), DFMA
Individual contributions:
  • Design of the storage components.
  • Structural and thermal FEA of the storage and housing.
  • All hand calculations to verify FEA models. 


Redesigned a rice cooker to store, wash, and cook rice for a more streamlined and intuitive user experience.  

This was a final group project for the advanced interactive CAD and CAE class at The Georgia Institute of Technology. The goal of the project was to demonstrate the modeling and FEA skills learned throughout the semester by redesigning a product.





Rice is the world’s most consumed grain. Those who eat rice consistently know that rice needs to be prepped, specifically rinsed, before consumption. In perhaps the most iconic love letter to rice in the film, Jiro Dreams of Sushi, Jiro’s apprentice spends an hour preparing rice — starting with a solid rinse — for a plate of nigiri. That being said, many people lack the patience to rinse rise for 3 minutes let alone an hour, or have issues with measuring out the proper ratio of water to rice and so the idea for a rice cooker that stores, preps, and cooks rice was born.




How the user operates the rice cooker:

  1. The user first fills the two storage bins with dry rice and water

  2. Once the user selects their desired settings, the rice and water funnel through the valves into the cooking bowl in the main compartment.

  3. The agitator then mixes and washes the rice with its blades. Once the rice is washed, the agitator pumps out the dirty water into the drainage bin and more water is released through the water valve.

  4. The rice cooker starts to heat up via the heating element and cooks the rice.

  5. Once cooked, the user opens the door of the rice cooker which is connected to the bowl, making it easier to get to the cooked rice.



Rice cooker with lid removed Ingredient storage Hand calculation to verify if the housing can support the weight of a storage section full of ingredients. The expected force was calculated to be 1.7 MPa. FEA to verify if the housing can support the full weight of the ingredients. The housing would only undergo 1.741 MPa which matches the hand calculation. This number was within the acceptable bounds of the design.


The storage section is designed to have removable and easily refillable bins. The bins are very shallow funnels with a quick connect that attaches to a valve that dispenses the rice and water into the cooking bowl. All valves and materials were selected to meet user food safety and convenience needs. 



Section view of the rice cooker Main compartment view 1 Rice agitator and drainage Main compartment view 2



The main compartment contains an agitator blade that also sucks up the water used to wash the rice into the waste water bin, a bowl that cooks the rice via a heating element, a vent to regulate pressure, and drawer slides that eject the bowl when the front handle is pulled. Structural analyses were performed of the agitator blades and door handle as well as a thermal calculation for the housing which can be seen below.



Thermal hand calculation to verify if the thickness of the insulation in between the walls of the external housing result in a safe wall temperature for a user to touch. The external temperature of the wall was determined to be 32.7 deg Celcius which is not hot enough to cause pain to the user. Agitator blade FEA determined that the stresses of washing rice are no more than 0.0688 MPa which is within the acceptable bounds of the design. The stress the agitator blade undergoes was calculated by hand to be 0.079 MPa. This value is 0.02 MPa higher than the FEA, but this is due to the assumptions used for the moment and moment of inertia calculations. Furthermore, 0.02 is an insignificant amount of additional stress and does not pose a risk of failure for the design. Handle FEA determined that the stress of a sudden forceful pull by the user, while the door is locked, would exhibit a maximum stress of 37.23 MPa. Although high when compared to other stresses, this is not high enough for the material to yield and is within the acceptable bounds of the design. Handle hand calculation to verify the stresses determined by the FEA. The calculated value is 37.27 MPa which matches the FEA.


Some potential future work for this project is: creating a prototype and fleshing out the electrical components and their wiring, developing software with an intuitive visual interface, and optimizing manufacturability with respect to materials, geometry, and cost.