SolVaCov's Prototype

The following steps will guide the user to build a Peltier cell based portable cooler for Covid-19 vaccines.

The construction begins with the manufacture of the casing for which the drawings of each piece and their corresponding CAD models are delivered. The material used for the prototype is PMMA, which has the ideal mechanical and thermal properties for the construction of a refrigerator.

Each piece has a clearance of .5mm. The sheet used was 5mm thick and laser cutting method was used.

There's two different elements for the inner compartment. The horizontal compartment which is the horizontal part of a compartment and the vertical compartment which is the vertical part of a compartment. In total there are two compartments so four pieces in total.

The material and method of cutting is the same as that of the casing.

The manufacture of these components was essential since here lies the vibration and damping system. In addition there is also the stacking system.

First, 4 pieces are manufactured via additive manufacturing using ABS. There are really only two different geometries so only two blueprints are needed.

3D printing:

Lower Supports

Lower Bracket (Type I)

Material: Printing Material Available Elastomer

Quantity: 2 Units

Files: support-inferior1.ipt, support-inferior1.igs

Lower Bracket (Type II)

Material: Printing Material Available Elastomer

Quantity: 2 Units

Files: support-inferior2.ipt, , support-inferior1.igs

In addition, for the construction of these supports, polyurethane foam is needed, which is placed between the flat surface of each support and the floor sheet in PPMMA. Taking into account that the shafts must be inside the holes of the floor.

Superior Supports

Superior Support (Type I):

Material: ABS

Quantity: 2 Units

Files: support-superioro.ipt, support-superioro.igs

Superior Support (Type II):

Material: ABS

Quantity: 2 Units

Files: support-superioro2.ipt, support-superiorio2.igs

With the help of an image of the prototype and its parts, the assembly is carried out. The gaskets are glued with cyanoacrylate (a.k.a. SuperBonder). Keep in mind that the inner compartments are the first to be glued, before assembling and gluing the parts of the casing.

The upper supports are attached with cyanoacrylate to the upper face. The lower supports are joined with epoxy resin as the cyanoacrylate reacts with the polyurethane foam.

List of Materials shown.

- Arduino Uno, 12V-3A adapter, DS18B20 temperature sensor, Peltier Cell, 12V medium fans, Small fans, Heatsink: small, medium and large, Relay module, 12C converter module, LCD, Jumpers, Protoboard

For the control system you must install the Arduino with the following scheme https://www.tinkercad.com/things/kwlOrfhxLhA for the basic configuration. In the process some modifications were made to simplify the construction and improve the operating system of the Arduino.

If desired, the final configuration should be installed as shown in the third picture.

MORE INFORMATION IN THE REPOSITORY :

video operating: Repository > Prototypes > PG 3 New Prototype > control module

https://uniandes.sharepoint.com/sites/202110-PROYE...

ARDUINO Program: Repository > Prototypes > PG 3 New Prototype > control module > arduino

Finally, a 2.5mm slot is machined into the side covers so the lid can be inserted and left with a sliding operation.

For the racks a blueprint was used as a reference and cut from a sheet of polycarbonate simulating its main dimensions. In order to improve the airflow, the gaps that allowed the passage of air in the racks must be maintained.

For the final assembly, the connected battery is placed in one of the compartments and in the other compartment the arduino and the LCD is inserted into the space dedicated for it. The batteries used are of the Tb-Plus No-Spillable Sealed Rechargeable Battery 6V-3.4AH/20HR model.

In the space of the back cover the cell and the module with heatsinks and fans attached are placed. The following images shows how it should look at the end.