Team 607 Eastwood Schools Compact Water Filter

Contact Name: Isaac Gibbons

School: Eastwood Schools / Team 607

BEST Hub: Montgomery BEST

SUMMARY

This is designed for the BEST Robotics Low G competition. It is a compact water filter designed to process and filter water in all states of matter. The model contains arrows and text explaining the design.

DESCRIPTION

One end is for ice, with a metal grate heated by a thermopile to melt the ice as it is pressed up against it by the screw-in cap. There is a port on the side for liquid water, steam, and water vapor in the air. The port has a grate that is cooled by the thermopile, so that vapor pulled past it condenses. The method used to heat and cool the grates, a thermopile, is a device formed by a junction of two thermocouples. Thermocouples are formed from a connection of two dissimilar metals, such as copper and constantan, a copper-nickel alloy. The connection changes its resistance to electrical current when its temperature changes, so it is often used for thermometers. A thermopile does the opposite. When electrical current is run through it, one end becomes hot, and the other end becomes cold. The filter takes advantage of this by connecting the ice melting grate to the hot end of the thermocouple and the condensing grate to the cold end. The pump can be electrically powered by a motor, or hand powered by a handle, which serves the dual purpose of turning the motor into a generator to recharge the battery. After the water exits the pump, it is run through three filters: a course filter for large debris, a cloth filter for dirt and other particles, and a charcoal filter for toxins and minerals. 

DESIGN PROCESS

The design was started after reading the rules to determine the functions necessary for it to perform. How to purify the water was thought out. Solar evaporation was ruled out due to the moon's temperature extremes and unreliability. Electrical power wasn't efficiently renewable given how expensive sending enough solar panels and equipment to the moon would be. Then it was decided that it would be built to be able to work under electrical or manual power. It is the second iteration. The first was a 9x12x9 box. It was large, complicated, and extremely difficult to print, though, so the simpler and more compact current design was taken up. it was decided that it would be minimally electrically powered to increase the battery life and to prevent a dependence on the battery to run it. Then the pump was designed to incorporate this decision. The filters were added due to the fact that water of all forms can contain unknown substances that may be harmful. The grates were added after consideration on how the solid and gas forms of water could be captured, given that the shadowed side of the moon is freezing, and the sunny side is boiling.

PART EXPLANATION

The picture above is a picture of each part together.

These are photos of the main filter body from various angles.

These are pictures of each piece, the ones on wood being done by a different teammate. List of parts from top to text: Pump paddle, Pump arm by itself, Pump arm with handle side view, Pump arm with handle top view, liquid water/steam/water vapor port cap, cover for thermopile, ball valve ball.

In this image, the section of the main body pictured looks rough because it was cut open to show a cutaway of the filter section. The thin cloth filter is present but is hard to see because of its thinness. 

CAD images. Top to bottom: Angled full front view, Full top view, Left end view, Right end view, Full back view, Complete part focus, Cutaway focus.

PARAMETERS

Print height: 80.01 mm

Print length: 203.74 mm

Print width: 195.28 mm

Print nozzle temp: 220 degrees Celsius

Print bed temp: 55 degrees Celsius

Print time: 42.5 hours

Print speed: 100%

PRINTING

Printer: Ender 3 V2 Neo

Infill: 5%

Brim: no

Supports: yes

Filament: PLA

NOTES

Some parts are designed to be glued to the filter body, such as the thermopile cover and the pump handle. Some parts are also not present in the printed version for various reasons, such as the condensing grate. In the final picture, the part looks bad because it was cut open to show a cutaway of the filtration section. This model is licensed under the Creative Commons-Attribution license to help spread BEST and Eastwood School Robotics Team 607's name and possible participation.