Pump Placement/orientation, Power & Flow-rates

[reVoxAHB]

Hi Gang,

I recently relocated my March 809 from the right side of my brew frame to the left lower area as shown:

The pump was mounted vertically, so to speak, so that in was down output/up, whereas now (again shown) the pump is horizontal, in on left/out at right. As a quick note, I have no priming issues; fine priming in either orientation.

With the pump mounted dead beneath my kettle and plate chiller close by, my longest run of silicone hose (to complete kettle --> pump --> chiller --> ferms) was 1 meter, with various little bits here and there to complete the setup. Now, the longest run (again, silicone throughout brewery) is 3m, and 2m back again, with various bits.

Having brewed on two occasions with the pump now at left, it would appear I've lost a tremendous amount of suck. My little ghetto hop filter screen (in kettle) that no-one could figure out how I was able to use without clogging (even all-pellet brews) clogged straight away:

I accepted this, and moved on to a 9" falsie (thanks Hutch!) thinking it would be less restrictive and compensate for new length of run.

No joy . Did a second brew using 230g pellet and 70g flower and again clogged, nearly straight away. I pulled the hose from the kettle valve at stuck run off and indeed confirmed nothing more than a trickle was coming thru the falsie (ruling out plate chiller clog, etc.). I started run-off very slowing afaik, massaging both the flow rate of kettle and output of pump so I don't think I pulled too much too fast creating a dense bed. Only thing I can think is my pump flow/suck rate has decreased significantly from new placement.

So the question is, have other brewers noticed a change in flow rates/overall performance with:

Pump position in relation to the rest of gear?
Pump orientation eg vertical/horizontal?

The pump was shifted left to be more integral with my HERMS.

Any tips on best placement? Centre or shifted (with some form of temporary mount) from left at HERMS to right at chill? I have already ruled out purchasing a second 809 :lol: , fwiw.

Cheers,
reVox

 

[Frank]

I would suggest that you actually have more suction now than before. If the screen is blocking quickly, it sounds like you have a large initial suction causing the blockage. At a slower suction hop material will not be drawn to the screen rapidly.
Have you tried pumping water to test your system in this configuration, with screen unblocked? Maybe try throttling your pump back next time you are brewing.

 

[porky]

Going from 1 meter of hose to 5 meters is a huge difference in resistance for the pump to have to overcome.
I don't use a pump, but surly closer is better as shown by how it used to work.
I wouldn't think vertical or horizontal would matter really.

Cheers,
Bud

 

[porky]

As Boston has pointed out, you might be getting more initial suction because there is a longer drop before the pump causing the blockage straight away. Do you have a valve you can open just a crack until wort is down to the pump?

 

[reVoxAHB]

I would suggest that you actually have more suction now than before. If the screen is blocking quickly, it sounds like you have a large initial suction causing the blockage. At a slower suction hop material will not be drawn to the screen rapidly.
Have you tried pumping water to test your system in this configuration, with screen unblocked? Maybe try throttling your pump back next time you are brewing.

Hmm. That's interesting. I would have thought the reverse, that more run would require greater suction, not provide greater suction :blink: . Anyone else have data or experience with this?

I haven't tried pumping water only to test my system in this configuration. Great suggestion. Will do so this week and relocate the pump back to it's starting position running the same. With pump on, I'll try an open palm to the top of falsie to see if I can feel any difference in pull between the two, and maybe run a volume analysis at full bore.

As Boston has pointed out, you might be getting more initial suction because there is a longer drop before the pump causing the blockage straight away. Do you have a valve you can open just a crack until wort is down to the pump?

The entire system (including every bit of the drop hose from kettle to pump) is primed with dilluted iodophor prior to opening the kettle valve, which is opened ever so slightly. The pump valve is next opened, and only a touch. I then play with the flow rates of either/or to achieve desired run thru chiller. So, it's not like wort is just dumping down an empty hose causing the impaction. Good thought, though.

When the system is working, I keep the kettle valve to where it's delivering wort with no air bubbles or break in wort flow to the pump, and regulate the speed thru chiller using the pump output valve.

reVox

 

[Frank]

I just looked at your photo again. It appears the old pump position was approx 40cm below the mash tun outlet, the new pump position is approx 80cm below the outlet, (just working on round figures here). I am working on the vertical height not length of pipe. Therefore you have gained 40cm of head pressure at the suction of the pump. I would assume the length of run to get to the pump would not have any consideration with 1/2 inch line as the flow rate is slow and friction would not be an issue.
This extra 40cm in head pressure would increase the efficiency of the pump and potentially give you additional flow rate. The height that you are pushing back up to the tun again is 40cm greater than before.
I would still be leaning towards increased pump efficency in the new position as the screens are getting blocked quicker, ie a greater suction through them. If you had lower flow before, hops and trub would stay sitting on the bottom of the kettle and not get drawn towards the screen.

 

[schooey]

Kay.... It seems the answer you seem to be all looking for is this;

When looking at a pump and efficiency, there are two key things; NPSHA (Net Positive Suction Head Available) and NPSHR (.....Required)

For a pump to shift liquid, the first has to be greater than the second, given the static suction head and the friction loss in the system.

Static suction head is the difference between the top level of where the liquid is being moved to minus the top level of where the liquid is being moved from

Sometimes this number is dynamic; Think liquid being pumped from a river into a water tower. The level in the river will remain relatively static whilst the level in the tower may increase by 20 odd metres. Hence the pump becomes less efficient the fuller the tower gets.

So if you haven't moved the height of the tank you are drawing from, or the height of the tank you are pumping to, the only change you have made is the change in friction loss by adding more length of hose or the amount of fittings to the system. Generally speaking with hose and fittings; More is more i.e. the more hose and fittings you have, the more friction loss (head loss) you have which equates to the less NPSHA you have and the less efficient your pump is.