283
edits
Project:Flow Hood: Difference between revisions
From London Hackspace Wiki
no edit summary
No edit summary |
No edit summary |
||
| Line 12: | Line 12: | ||
== Construction and Materials == | == Construction and Materials == | ||
== Frame == | === Frame === | ||
We need to construct a frame: perhaps weld together some steel box section; or chop up and repurpose an old shelving unit; or construct it out of [http://www.makerbeam.eu/ makerbeam], [http://www.technobotsonline.com/construction-kits/openbeam.html openbeam] or [http://www.aluminiumwarehouse.co.uk/EasyFix_Tube_Connectors/c180/index.html easy fix]. | We need to construct a frame: perhaps weld together some steel box section; or chop up and repurpose an old shelving unit; or construct it out of [http://www.makerbeam.eu/ makerbeam], [http://www.technobotsonline.com/construction-kits/openbeam.html openbeam] or [http://www.aluminiumwarehouse.co.uk/EasyFix_Tube_Connectors/c180/index.html easy fix]. | ||
== Work surface and side panels == | === Work surface and side panels === | ||
Because we will be using 70% ethanol for sterilisation, the materials used for the sides and work surface must be resistant to this. Unfortunately 70% ethanol kills perspex over time so it looks like we will need to use glass for the sides and perhaps a sheet of stainless steel for the work surface. | Because we will be using 70% ethanol for sterilisation, the materials used for the sides and work surface must be resistant to this. Unfortunately 70% ethanol kills perspex over time so it looks like we will need to use glass for the sides and perhaps a sheet of stainless steel for the work surface. | ||
== Sealant == | === Sealant === | ||
The inside edges of the flow hood need to be sealed and air tight. As with the side panels, the sealant must be resistant to 70% ethanol, so ordinary bathroom sealant is out. So far the only ethanol resistant sealant I have found is [http://www.ppg.com/coatings/aerospace/sealants/indsealadh/Pages/default.aspx PRC Rapid Seal] which is rather expensive. A cheaper alternative that may work is simply sticking plumbers teflon tape along the edges. However the ethanol may work its way under the tape and cause the adhesive to loosen. | The inside edges of the flow hood need to be sealed and air tight. As with the side panels, the sealant must be resistant to 70% ethanol, so ordinary bathroom sealant is out. So far the only ethanol resistant sealant I have found is [http://www.ppg.com/coatings/aerospace/sealants/indsealadh/Pages/default.aspx PRC Rapid Seal] which is rather expensive. A cheaper alternative that may work is simply sticking plumbers teflon tape along the edges. However the ethanol may work its way under the tape and cause the adhesive to loosen. | ||
== Filters == | === Filters === | ||
HEPA rated filters will remove any bacteria and other contaminants from a flow of air. They are often used in air conditioners and air purifiers. The entire 'ceiling' of the flow hood must consist of filters, so the dimensions of worksurface of the hood are constrained by what size filters we can find for a reasonable price. So far [http://www.amazon.co.uk/Fellowes-Filter-Large-Purifier-9370101/dp/B0067D7D1S these filters on Amazon] appear to be our best option - we can put two next to each other to achieve a 64x42cm work surface. | HEPA rated filters will remove any bacteria and other contaminants from a flow of air. They are often used in air conditioners and air purifiers. The entire 'ceiling' of the flow hood must consist of filters, so the dimensions of worksurface of the hood are constrained by what size filters we can find for a reasonable price. So far [http://www.amazon.co.uk/Fellowes-Filter-Large-Purifier-9370101/dp/B0067D7D1S these filters on Amazon] appear to be our best option - we can put two next to each other to achieve a 64x42cm work surface. | ||
== Blower/Fan == | === Blower/Fan === | ||
We need to find a blower that will blow the right amount of air through the filters to create laminar flow. Instructions on how to figure out the maths of achieving laminar flow through a HEPA filter can be found in [http://fradnai.free.fr/docs/doc23.pdf this helpful PDF]. | We need to find a blower that will blow the right amount of air through the filters to create laminar flow. Instructions on how to figure out the maths of achieving laminar flow through a HEPA filter can be found in [http://fradnai.free.fr/docs/doc23.pdf this helpful PDF]. | ||
