I am trying to spec a project, general theory of operation:
have 4 fluids: air(sterile), and 3 aqueous solutions
use the air to flush a (semi) ufluidics card between reagents
the first two reagents are ~mL washes through the entire card (Q=1200uL/min <or less is ok> ), spec grav~ 1.1 , 0.9 - respectively
the final reagent is 100uL and has spec grav=1, it has to flow at about 1/2 the rate of the first two reagents
between each reagent, the card is flushed with the air line.
I am trying to figure out what kind of pumping and valving system is best for this application.
my search so far has turned up: pump
= peristaltic (we use this in the lab, works well) http://www.ismatec.com/int_e/pumps/t_mcp_bvp/mcp_proc.htm
this pump has a max pressure drop of ~15-22psig (depending on tubing)valves
= micro isolation rocker valves (avsco series 067) http://www.ascovalve.com/Applications/Products/MicroIsolationData.aspxtubing
something like Tygon MHLL, Norprene
I'd like to run reagents into a block manifold controlled by four of these (or similar valves) then a single line to the pump (with some check valve and/or sterile filter to prevent upstream contamination)
I am new to valving applications and am a bit confounded by figuring out what orifice size I'd need and can only find information about control valves operating at much higher flow rates.
1. how to keep the air sterile, is a .2u filter on the inlet ok?
2. how to compute the valve size needed for each reagent
3. filters, check valves, misc small parts I may not be thinking of?
thanks for looking