If you are wanting to recycle the fluid ( it would be good at the price) You will need to ensure that the top cold zone is as cold as possible, preferably higher than the deep fryer, and with a good source of cooling. A water jacket with a pump to circulate the water and a chiller to make it cold will work best, using an old draught chiller as the cold water source. You need to keep the board in this zone for a while after reflow, to ensure that all the liquid condenses on it and then drips down into the bottom, and keep it running after you turn the heat off till it is at room temperature and you want to dispense it back into a sealable pressure vessel to store it.
Had that where I used to work, though there it was an ultrasonic cleaner using TCE, and it used the vapour phase to clean the fluid, as you could collect the drip off condensed liquid into a bucket and concentrate the dirty fluid down to a sludge for dirt removal. That would take the dirtiest castings you could find and leave them as bare clean white castings. Would strip a PCB of the resin ( except for the one conformal coat that survived no matter what) and all printed and painted parts except the copper and solder in around 3 minutes.