When developing convertible PPE, the key parameter is the size of the room into which the protective suit is converted. An important value here is that the mechanism would work in such a way that the room would move apart not only in length but also in width. So, being behind the back in a folded state, the tent should not have a width of somewhere no more than 40 centimeters. In the extended state, the pallet room should already be more than 60 centimeters. This operation of the mechanism should be facilitated primarily by the fact that the ventilation system of the protective suit should be divided into two parallel blocks.
Here in the figure you can see the right ventilation unit. In turn, it consists of a filter box (1). For the time being, it is planned to use HEPA filters. Also here I decided to use, as I already wrote, an axial fan (2) and a brushless electric motor (3) of the type used in quadrocopters. In this case, the direction of the air flow can be reversed, which is provided by the technology. It also provides for the ability to adjust the strength of the air flow. The maximum power of the electric motor should not greatly exceed 30 watts. One-tenth of this power for two motors is enough to supply air under the helmet and provide a comfortable environment. Cooling will require approximately three times more air, as shown by preliminary calculations. This was an interesting enough result. And this is only part of the heat, the rest of the heat should go away in the usual way with convection. The highest air consumption when inflating the tent room. In this case, you will need the full power of the two motors and a time of approximately one minute. The highest air consumption when inflating the tent room. In this case, we need the full power of the two motors, so that the time spent is approximately equal to one minute.
Fans cannot obviously generate pressures well above 500–800 Pascals. Of course, it is possible to fill a transformable room at this pressure, but not very productive. It seems almost impossible to fold the tent by pumping out the air. At least it’s hard, if you keep the acceptable forms assembled. For this there is a frame. This framework must also be active. This force is created by pneumatics. The micropumps that are to be used here must have a larger size and performance than those planned to be used in bracelets. I have seen similar micropump offerings on the market, and their characteristics are quite sufficient for this job. This is a common telescopic support system and everything has to work in parallel. I have already managed to increase the space by moving the supports away from the ventilation. But this is still not enough. The length of the tent is about a meter, but I would like to have one and a half. I need to look for another “invisible corridor”.
https://medium.com/@SeregeSokolov/spanish-flu-in-literature-3496ba61b2
