License to Kiln

Project undertaken in course year 2022-23 with the Stanford Woods Institute for the Environment

Project Goal

Reduce harmful carbon emissions from brick kilns in Bangladesh through implementation of an automatic coal feeder.

Our year's challenge was to improve on the automatic coal feeder designs of previous ME170 teams to account for coal clogging in the device when the coal is damp.

Top of kiln, showing coal feeding locations

Project Motivation


Previous teams designed a device that is successfully able to feed dry coal into a kiln autonomously at a specified feed rate.

However, in situations on kilns, coal is often damp from rain or to reduce particulates in the air. In these instances, the device clogs immediately

High Priority Requirements

Ethical Considerations

Maintaining firemen's ownership over their product.

Working with the kiln owners to lower harmful emissions.


We designed an internal fan that rotates with the previous teams' feed wheel, which is able to disturb the coal and remove both columned and domed clogs.

System assembly

Entire system with funnel where coal is placed, and feeder mechanism suspended on bricks

Fan geometry

The fan is attached to the feeder rotor inside the funnel, spinning through the coal to keep it agitated and mixing.  The coal falls through the single hole just above the fan and into the feeder.  

Fan moving coal

Coal being agitated so it continues to fall through the feed hole without clogging

Coal output over rotations

We ran the device over 20 rotations, and found that the output was consistent over that period of time.  We did this test with two different starting masses of coal in the funnel (900g and 3600g) and achieved similar results

Coal output over time

We ran the device over 1.5 hours, and similarly found that the coal output was consistent over that time

Student team

TRip to Bangladesh

Over winter break, two of the teammembers traveled to Bangladesh to meet the people involved and see the kilns in operation

Entering the kiln

Team picture

Up close with feeder

Discussing the feeder

Looking into the kiln

Current means of inserting coal into kilns

Future Work