Once my vacuum died while I was doing some filtering. As it would take few days to obtain replacement and I wanted to finish the process ASAP I built very simple replacement.
Legend to (crude) diagram below:
- bottle - I used bottle, so the cylinder could rest on it, could be anything really if cylinder is properly secured
- hole - 2mm hole below the buchner
- shelf - perplex circle with a hole in the centre for buchner filter, hole has small rubber seal
- filter - buchner originally, could be any filter really
- cylinder, 150mm diameter perspex cylinder
- air pump connector, thats where hose from air pump is attached
This little quick fix diy forced filter worked much better than vacuum. I didn't need to clean vaccum bottle every time I needed to filter something, instead I could use any container. Originally it was a bottle, but later when I built a stand for the cylinder I could filter to any beaker. The cylinder itself was a leftover from construction of a anti-nitrate aquarium filter, 150mm diameter, bigger diameter would be easier to handle. I didn't put that on a drawing, but the cylinder has 2 sections with rubber seal and 3 clip-on locks - the type you get on tool cases. On top glued in small connector for hose from aquarium pump. Below the filter little hole which lets the pressure out.
Pressure in a cylinder above the shelf is higher than below. That's why is important that the shelf itself is glued on the outer rim and has good seal where the filter goes in.
As the air is pushed in no corrosive gases are going through the pump. To prevent diffusion of gases the hose was only 4mm and around 2m long - popular silicone air hose for aquarium.
It is easy to control the pressure by fitting standard aquarium hose T-connector - one from air pump, one to the filter, one to the room :mrgreen: The branch going to the room has a valve.
I never got replacement for the vacuum - wasn't needed anymore :mrgreen:
