An Ergonomic and Efficient Chula

By: Pulkit, Rahul, Mahak, Rittick, Gautam and Kuldip Siyani

May 2018

Introduction

The project was previously defined as Multi-Source Chula which was basically to for the people in remote areas where wood is not easily available and the people have to go to great lengths to deal with this literally and figuratively. But the field visits gave us very little exposure to this problem because of the abundant availability of wood.

 

People who prefer gas over chullah give the following reasons:

1. TEMPERATURE CONTROL: It cooks some food (that require less heat) faster because the heat can be controlled easily

2. DIFFICULT TO USE: Gas is less messy

3. HEALTH ISSUE: A number of people were suffering from the problem of smoke but did nothing to mitigate the same

4. INEFFICIENCY: The chulas they are using are very inefficient and lose a lot of heat in convection from the natural draft

5. FUEL PROBLEM: They suffer greatly during the rainy season because of wet wood. So they sometimes turn to gas stoves or start collecting the wood in the house.

 

In these field visits we observed that the designs of there traditional chulas lack a proper structure and are very inefficient. Also the designs have many major faults that make it very difficult and problematic for the user to operate.

 

Problem Statement

The problem statement is to make changes to the traditional model of the chula making it more efficient, add the feature to use multiple sources and solve other problems (listed below) and to improve the general feel, usability/ergonomics of the chula.

We have tried to make an impact on the following:

1. Time of Cooking and Preparation Time of the Chula

2. Giving it a clean feel to improve the user experience by adding some extra features while ensuring minimal cost.

3. Efficiency: fuel consumption of the Chula

4. Safety: The Heat and Smoke outside the Chula

5. Exploiting the heat wasted in smoke and ash

 

The Model Developed

The model was developed keeping in mind the mistakes and developments in the past and the practices followed by stoves all over the world (Some pictures of those are given above). The main designs that inspired the final model were

  • Rocket Stove (that makes use of long TWISTED TAPES (SVIWLER)

  • Fireplaces in cold countries (that uses the advantage of multiple flow inlets and a packed structure to maintain the heat of the device)

  • Twisted Tapes (a part that is put under base of the utensil to modify the flow of the hot air and flames to increase efficiency)

Twisted Tapes (Sviwler)

The chula is made of clay and the supporting parts from scrap metal. This maintains the very attractive feature of no cost to the users of the chula. All woods, coal, dow dung and other solid biomasses can be easily burned in this stove.

The model has the following different parts:

1. The main body of the chula

2. The control disk to regulate the air flow to control the flame/heat/temperature of cooking

3. Ash tray

4. A conical cover to support different sized utensils

 

A number of apertures ensure that the air flow is sufficient.

1. Primary Air from the bottom through the ash tray (to be used only in Coal Fires)

2. Secondary Air (From the Feeding Pipe and the hole on the top front)

3. Tertiary Air (from the hole on the back)

4. Observation and Blow Hole for kindling the fire and to pour the fuel.

5. Chimney (to release and route the smoke)

 

Prototype

The prototype was made according to the model developed. It should be noted that the model is only to show the different essential parts and is not to made to scale.

The big idea is to take this small 3D-Printed model and show it to people and aid them in making the chula, which will cost them nothing as the soil and the binding material (dung or husk) is readily available.

 

REFERENCES

https://www.fireplaceproducts.co.uk/blog/11-stove-parts-you-need-to-know/

https://www.wikipedia.com/en/Rocket_stove

https://www.researchgate.net/publication/275483734_Development_of_a_fuel_efficient_cookstove_through_a_participatory_bottom-up_approach

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