HX problems

[MaltAlchemist]

I purchased a stage 5 heat exchanger and upon recommendation of the "engineers", I needed only a stage 1. So...........instead of spening 4K for new horizontal bars, I machined mine down to a stage 2. SO I got 200F wort coming in at 10 gallons per minute and city water at 55F-65F at 20 per minute. I added a stage after every brewing week.
Stage 1 (40 plates) 3hrs knock out and 88F wort in FV!
Stage 2 (80 plates) 3hrs knockout and 88F wort in FV!!
Stage 3 (120 plates) 3hrs knockout and 88F wort in FV!!!

WTF???????!!!!!!!

I have to let my wort cool down overnite and add yeast the next day. I know what I am doing is "mavericky" but I have no other choice right now. Help?

[En' Garde]

I would try to use an empty jacketed ferm tank to use as a "cold liquor tank". Put at least a 1.5 x of kettle volume in your tank and chill the water down to 36 oF. Hook up your mobile pump to pump your chilled water through the HX, you'll get better HX and colder wort and probably use less water than you are using now. If / when it works look to buy a jacketed tanks that you can dedicate for a cold liquor tank.

Cheers

Eric

[SRB]

Brand new HX?

[kai]

Probe on the FV isn't buggered, is it?

[Coast]

I agree w/ En Garde on this. If you don't have the option of adding a glycol side to the h/x then use the tank method to cool your water. If your water is about 55 then you really can't get wort past ~ 80. The tank method is really a great way to cool wort quickly and it keeps you from over loading your glycol system. Now I wish I had a cold liquor tank! Feel free to contact us if this is not helpful.

[sbradt]

HX problems

I agree that a cold liquor tank of some sort is going to be beneficial but I disagree about not being able to get below 80 with 55 degree water. As long as you have a fair amount of time, you should be able to come pretty near to equilibrium.

Have you considered running the water at a slower flow rate to see if it is simply going through the HX too quickly to pull out the heat?

Based on your stated times and flow rates, it sounds like you should be cooling about 58 Bbls of wort with 116 Bbls of water. Is this correct?

What is the outgoing water temperature?

Do you have the correct flow directions for the design of the HX? Seems straightforward but it isn't always.

The company that manufactured the HX should be able to provide specifications as to the BTU/hr of heat exchange at given flowrate and temperature differential.

[lhall]

You should be able to get to within 5 deg F of the water temp. Are you sure about your temperatures? Is the water really 55 F? That's nice and cold for city water, although you are in the mountains. Is your wort really 88 F? Are the plates assembled correctly? What is the water temperature coming out? Are you really getting the stated flowrate of water? And you don't want to choke back the water flow, the more flow the cooler the wort.

[SRB]

...Do you have the correct flow directions for the design of the HX? Seems straightforward but it isn't always...

That's why I asked if it was brand new. If not maybe someone put it back together incorrectly after cleaning.

[MaltAlchemist]

Hx Revisited

To answer a few questions:

I do have a cold water tank, but it just holds the city water. I thought I could hook up my glycol to it but it wont work. I thought about soft copper and an imersion chiller, but the cost of all that copper is too much right now. I am working on getting one I can either chill with glycol or R-22. The water coming out the HX is luke warm. I thought my plates were screwy, because it was a used Hx and I had to take apart and clean and reassemble, but I believe (to the best of my knowledge because I took it apart last night after my brew to double check) it is correctly counterflowing. I will check with the manufacturer to be safe.

the brewhouse pump is as slow as it can go. I've tried adjusting the speed of cold water and speeding up just wastes water and slowing down heats up the wort.

My real question is after I tripled the number of plates I still get the same thing....why? I thought it would cool down more because of more plates. I thought that if I added more plates, my water would get hotter and my wort would get colder. Am I in the twilight zone?

[lhall]

Something is screwed up with the way the plates are arranged or the piping is hooked up. The water coming out should be hot, 150 F.

[ScottV]

It sounds like the wort and the cold water are flowing in the same direction and not counter flow or the stages that you have added are not installed properly and are being bypassed. Make sure everything is flowing in the proper direction.

Scott

[Coast]

Is the wort inlet and water inlet on opposite sides of each other on the end plates (counter flow)? If they are flowing in the same direction then that could explain the lack of heat being exchanged. You should be able to recover 160 - 170 degree water on the out put. It sounds like you have tried slowing down the water output. And with all those plates there is a lot of surface area. Can you get a layout of the plates from the manufacturer? At least you know it can only get better.

[liammckenna]

You mention the brewhouse pump is as slow as it will go.

Try speeding up the pump and restricting the flow at the outlet of the HX.

The pressure should not bother your HX. At steady state, you should see a significant pressure drop across the plate pack.

I find with our HX that it doesn't 'fill' (the plate chambers) properly without at least 1 bar of pressure.

Good luck,

Pax.

Liam

[Moonlight]

Common problem is restricting flow into the HX, instead of the outlet. If the restriction, (ditto for slowing the pump), happens before the HX, it can lead to the HX not being completely full and in so not pressing on every square inch of the HX internal surface. Without that efficient contact, you won't have good results.
I would expect no better than 10 F differential of city in to wort out, but you can reasonably expect to closely approach that.

[jimvgjr]

I agree with Linus and suspect this has something to do with the streaming of the plates. Likely the wort has a direct path between the inlet and outlet and is not being forced to flow against the city water plates- or has very little contact with the city water plates.

I'd try to contact the HX manufacturer and explain the application, provide the model and serial of your plate. They should be able to provide a solution (a suggested plate schematic). Was the HX used for Wort Cooling before? It could be as simple as one or two plates in the wrong position or some pass plates added.

I know it seems like simply adding surface/plates would be the answer, but without the turbulence and plate contact it is impossible to exchange heat.

Good Luck,

Jim