av rkr » tis nov 10, 2015 6:39
Right now there are several top end packings, SPP, Propak, Propak's chinese copies, Helipak, Dixon ... Out of those I know based on empirical testing that SPP has HETP of around 28mm and Propak is advertised as having similar performance by the manufacturer which I consider a reliable source. The chinese copy of propak does not meet the original in appearance, holes not punched through - so I suspect that it can't match the original in performance. Helipak is similar in construction to SPP but it doesn't have those small loops where liquid film can cling, thus I suspect worse performance from that packing. Dixon I tested against SPP and it had a HETP slightly above 30mm and with reduced vaporspeed the HETP was going down as well, probably a good match for SPP at 12"/s as I was testing at 20"/s.
It would be very interesting to be able to test all those back-to-back but it seems that manufacturers do not want that (at least Cannon instruments didn't). I have SPP and equipment to do tests so if someone wants to donate me 2 liters of those high end packings I'll run a back to back test against SPP with it.
Slainte, Riku
Right now there are several top end packings, SPP, Propak, Propak's chinese copies, Helipak, Dixon ... Out of those I know based on empirical testing that SPP has HETP of around 28mm and Propak is advertised as having similar performance by the manufacturer which I consider a reliable source. The chinese copy of propak does not meet the original in appearance, holes not punched through - so I suspect that it can't match the original in performance. Helipak is similar in construction to SPP but it doesn't have those small loops where liquid film can cling, thus I suspect worse performance from that packing. Dixon I tested against SPP and it had a HETP slightly above 30mm and with reduced vaporspeed the HETP was going down as well, probably a good match for SPP at 12"/s as I was testing at 20"/s.
It would be very interesting to be able to test all those back-to-back but it seems that manufacturers do not want that (at least Cannon instruments didn't). I have SPP and equipment to do tests so if someone wants to donate me 2 liters of those high end packings I'll run a back to back test against SPP with it.
Slainte, Riku