I think i've figured out my herms problem

[Bionicmunky]

When using my HERMS I always have problems with air being sucked in at the Tun end/low output flow - tis fine with water, but with a mash it's really struggles.

I think I've figured out why......

My H/E coil is 10m of 8mm copper, now that's gonna cause some pressure differentials :wha:

I'm gonna reform out of 10mm and perhaps cut the length down a bit :whistle:

Anyone got any views?

J

 

[prolix]

10 m of 8mm tube :shock: I was thinking of 0.75m which would give about 6.3kw per degree difference water bath to liquor temp or it would take 13mins 20secs to increase the liquor by 1 degree for 20 litres of liquor @1.5 litres/min, ignoring losses form pipe work after H/E with an average differential of 1c. thats why I have a PID and am going to autotune, those sums hurt also I only loose about 1-2c in 90 mins at the minute anyway so system is ok. Yours is about a 51.5kw system btw at 1 degree differential and would take exactly the same amout of time as mine at that flow rate because once the water it at temp no more heat transference can take place. but you could pump it faster at 12 L/min and get a lovely compacted mash but it would heat 20L in 1 min 40 seconds assuming water bath to be heated at same rate as heat loss.

I need a beer :drink:

 

[prolix]

oh by the way, the 8mm pipe is better than the 10mm for this situation as opposed to an I/C. and because of the low flow rates there should not be a worry about pressure losses, obviously 10m does make a difference