DD Plate Chiller

[bern]

Hi guys
I'm having a few issues with my Duda Diesel plate chiller. I have the wort flowing very slowly from my kettle through my chiller which only results in a trickle into the fermenter. If I open my ball valve anymore I can't get the wort down to pitching temps. It usually come out around 40C. It's taking me around 1 hour to cool 23 litres to about 24C. I'm thinking about install a ball valve on my wort output to keep the wort in contact with the plate chiller a little longer. Will this help??? Any advice will be highly appreciated.

 

[Batz]

How fast do you have the water running, and is the water running in the opposite direction to your wort?

 

[bern]

I can fill a 20L bucket with water in around 10 minutes. Yep it's running in the opposite direction.

 

[pk.sax]

Questions:

1. Gravity or pumped wort flow?
2. Are all your hose clamps on really really tight?
3. If pumping, is the pump properly primed?

I've found my plate chiller (also a DD) is a significant reducer of flow, I'm guessing they all are. But what always causes issues is if the pump isn't fully primed or the hose isn't clamped down tight on the barbs at the pump and the chiller. If it is all leak free and primed it works a treat. Have had had to feed wort into the pump with a jug to prime it once... Kettle isn't too high off the ground.

 

[bern]

It's a gravity fed setup. I don't use hose clamps but I have never had a issue with leaks. The hoses seem to fit on snug. I do have a little brown pump but I haven't added it to my brewing setup. Not sure if having the plate chiller horizontal or vertical makes any difference?

 

[Dunkelbrau]

Orientation shouldn't matter, but water flow should be full if you want to cool quickly. Also if the line is pulling air in then you won't have full contact with water. Put some clamps on, its cheap and easy.

How do you slow the wort flow? At the kettle or at the FV? If you're slowing from the kettle, It doesn't allow complete contact with the cold side of the chiller. I'd restrict after the chiller with a cheap plastic valve to allow the wort greater contact with the water flow.

Also invert your water flow. Cold in at one end, wort in at the other. That way the colder water is contacting colder wort, rather than having the water increase parallel to the wort.. It will cool more effectively.

 

[pk.sax]

Reason to put clamps is that even as it 'looks' like a very snug fit it is pulling in a little air and the system as a whole is losing the suction needed to get it through. Chuck on some clamps on all barb connection, as said - cheap and easy to do.

Also make sure the hose end in the fermenter is fairly below the wort in of the chiller.

 

[bern]

I usually slow the wort flow with the kettle. I will run a few tests. Thanks for the feedback guys.

 

[pk.sax]

Oh poop. Just re-read your original post. Looks like flow wasn't your issue, just that it's not cooling down quickly enough. Same-ish. When I brewed with Canberra water (hellish cold) it'd knock it down to temp quite easily. Not so elsewhere. Look up pre-chilling the cooling water. Some guys suggest filling up a fermenter full of chilling water and use that for the heat exchange rather than tap water.

 

[TheWiggman]

20l bucket of water in 10 mins = 2l/min. That's not much water. Increase your water flow and I'm sure you'll get a big improvement.

 

[technobabble66]

Yeah, i run a plate chiller that would half fill a recycling bin in the time it takes to drain the kettle. No idea how much that is - 40L? Definitely a lot more than 20L though. And that's keeping the flow pretty low (i thought). Obviously depends on the "ambient" temp of the tap water, however 20L seems fairly small (i get mine down to 22°C. Increase the tap flow. Hadn't thought of restricting the wort flow after the chiller as being optimal - makes sense, thanks for that!

 

[djar007]

Got any pictures of how it is setup?

 

[JaseH]

Something is not right, mine DD plate chiller is gravity fed(not restricted) from the kettle and I can fill a fermenter with 20C wort in around 5min. My tap water flow is reasonably quick, I would easily send 2+ times as much water through the chiller than wort. Is the water coming out of the chiller hot? What size chiller do you have?

 

[technobabble66]

Sorry, I should've specified: mine is a 20 plate chiller and the wort is gravity fed through it. The wort volume is about 23-27L. Chills it to 24*C in 5-10mins. Ambient tap water temp is ~16*C (I think). At a guess, 40-50L of tap water is used to do the chilling.
Hope that helps.

 

[bern]

Yep the water is coming out of the chiller warm not hot. It's a 30 plate DD chiller B3-12A model. I may try increasing the water and wort flow a little and adding hose clamps to the barbs.

 

[technobabble66]

Ok. Just increase the flow of the water, not the wort.

 

[HBHB]

Your outdoor tap is probably capable of running 9lpm. Run it full on with clamps insitu and you should be able to increase your wort flow to near fully open and still get cooled wort in a reasonable time frame.

 

[TheWiggman]

With low flow the water coming out of the chiller should scalding. I'm talking burns if you touch it. If you aren't getting really hot water coming out at low flow AND the wort's only coming out at 23°C (assuming the tap water is much colder) then there must be a contact issue inside the chiller itself. Maybe a blockage or similar, so only a small portion is making proper contact with both fluids.
I don't know how they're constructed internally but something's up.
Start as suggested. Crank up the water flow with the wort at a trickle. Gradually bring up the wort flow until you see the temp start to rise and if it still takes you much longer than the times suggested from others' experience, you either can't read out/in or there's a blockage in your chiller. Can't really be anything else. Excluding witchcraft.

 

[klangers]

How long have you had the chiller for? It's possible that it's fouled - crap's built up on the plates inside and reduces the heat transfer rate. Try giving it a good soak in sanitizer/mild acid solution to dissolve this. Don't put it in anything too alkaline as this may cause a build up of copper oxides - this may have hurt the efficiency.

A blockage may be a problem - you should always backflush straight after using it to free any blockages and reduce fouling.

Industrially, plate HEXs are rather hardy though, so I personally doubt this is the issue.

The heat transfer rate inside plate HEXs is highly correlated to the flow rate. Higher flows = greater heat transfer rate. What I have done with my HEX is I put it in a pump recirculation loop so the overall volume out of the kettle is low, but the rate through the HEX is high. This gives a greater heat transfer rate and a faster wort drop overall. I'd advise against judging the effectiveness by measuring the cooling water outlet temp - if it's hot then great, but the heat transfer rate can be high without the water being really hot if the flow is high enough.