All about connecting your Cooling Water Supply to your Condensers!

Kapea

@rossco said: BTW I don't believe this, I just don't see it as important. Logic says flow should be laminar in both water and vapor, especially if the setup is not counter-current. Differential heat transfer between the inlet and outlet could cause disruptions. However they can see inside their condensers so I'll have to defer...

No laminar flow - if there was you would have a very inefficient heat exchanger, only vapor in the boundary layer would condense.

Also vapor collapsing to liquid phase creates a vacuum, creating turbulence. That's what huffing is caused by in the product condenser.

@grim said: …with the addition of vapor enrichment/mass transfer as condensate and vapor move countercurrent through the tubes.

AHA! So I really DO have a fifth plate! I like the way you think @grim !

Kapea

Running my SD four plater I draw water from a standard hose bib. I screw a brass splitter onto the hose bib that splits into two hose bibs. Each of those two hose bibs has a ball valve, allowing proportioning of flow going to the two cooling lines. At the cooling water inlet to the deflegmator I have an inline SD needle valve. On the cooling water outlet to the deflegmator I have a SD inline thermoport and thermometer. I regulate cooling water to the deflegmater based on cooling water outlet temp (and level of liquid on the plates). The cooling water flow through the deflegmater is minimal, except for when I want 100% reflux.

The other side of the hose bib splitter goes to the shotgun product condenser which I run counter-flow. I set the cooling water flow rate so that the distillate comes out within 5 degrees F of the cooling water inlet temp or so. But that number is not that important, it is just a preference so that I know the temp correction for my alcometer when I take grab samples. ("...some day my prince parrot will come...)

grim

When I first started experimenting with controllers and proportional valves, I ran off a single pump. What I found was that with a single pump, and a Y, I found that adjusting one of the condensers impacts the flow in the other. You might not notice it at all with a valve and hose, but try it with a pid controlled valve setup and you'll find that when you adjust one condenser, the other controller needs to adjust to compensate, which throws the first off, which adjusts again, and you'll see a wobble between the two, until they re-stabilize. Granted, this was before I could set a pid.

Did not happen with my municipal water, since I have serious flow and pressure. I would assume if I used a large enough pump with the same amount of head pressure and flow restriction, it would work the same.

I use two pumps now, much easier to dial in the controllers when they aren't fighting each other.

punkin

By all accounts moving the needle valve to the outlet of the reflux condensor will give you better control.

Anavrin

Heres a quick diagram of what i was rambling on about earlier, it should allow adjustments to the dephlagmator flow without affecting the flow in the product condensor flow.

The idea with the two extra valves alows the cooling water flow through the RC to be reduced by creating a bypass or short circuit.

You still set the cooling up as usual with the two standard valves, the ypass valve should be closed and the additional valve is full open.

once you have 100% reflux and are at the point where you want to start collecting, you start to open the bypass valve, this creates another path for the water so the flow through the RC reduces, however the total flow through the RC and bypass valve is equal to what you had originally at 100% reflux, so adjustments dont affect the pressure/flow to the product condensor.

If you find that once the bypass valve is fully open, you still need to reduce the RC flow, start to close the additional valve, as the bypass is open, it should only have a minimal effect if any on the product condensor flow.

punkin

@Moonshine there's an existing thread here somewhere with cooling chat in it. Could we split all this stuff off into it so it doesn't get lost?

YouDeManInAdvancePunkin

Kapea

@punkin said: By all accounts moving the needle valve to the outlet of the reflux condensor will give you better control.

It would be a bit crowded looking over there on the outlet side with the thermoport and all.

Which leads me to ask; should I be able to shut the water flow off completely with a StillDragon Push Connect Valve? Even with the set nut all the way backed off, I cannot get the valve to close all of the way. Water continues to flow. Do I have a faulty one?

When I run full-on gin runs with my Carter head I want to use the deflegmator in 100% reflux so I can change out gin baskets on the fly (engage the clutch, so to speak). I would like to use that push connect needle valve to stop water flow when in infusion mode.

brewsmith

A bit behind on the posts here, but going back to the air bleed valves @Kapea was talking about, I know that Swede on AD used a maid-o-mist 67 valve such as the one here

punkin

@Kapea said: When I run full-on gin runs with my Carter head I want to use the deflegmator in 100% reflux so I can change out gin baskets on the fly (engage the clutch, so to speak). I would like to use that push connect needle valve to stop water flow when in infusion mode.

It would be embarrassing for someone who works with water to have the directional valve on backwards no? @-)

There is a diagram printed on the side showing which way they have to go.

vooharmy

@grim said: When I first started experimenting with controllers and proportional valves, I ran off a single pump. What I found was that with a single pump, and a Y, I found that adjusting one of the condensers impacts the flow in the other. You might not notice it at all with a valve and hose, but try it with a pid controlled valve setup and you'll find that when you adjust one condenser, the other controller needs to adjust to compensate, which throws the first off, which adjusts again, and you'll see a wobble between the two, until they re-stabilize.

My experiments have lead me to a very similar conclusion, ultimately though I stuck with 1 pump with the product condenser feeding the reflux condenser. Solved the problem whilst reducing the complexity, and now my temps are even more stable.

Kapea

You mean the little white smug that vaguely resembles an arrow? Damn! How did I miss that? :\">

(Thanks Punkin!)

Myles

I very rapidly changed from pond pumps in my recirculation tank to an irrigation pump. This pressurises my supply lines to 1 barr and I run independent flow control on the inputs to all the condensers in the system.

It works for me. I used to have 2 stills fitted to the same coolant supply and just switched off the condensers that were not in use. If you feed the condensers from the bottom and use 3 way valves on the coolant supply lines you can even use the 3rd port to drain down the condensers that are not being used.

EDIT: may be obvious but both valves are in either red position or blue position at the same time.

punkin

@Kapea said: You mean the little white smug that vaguely resembles an arrow? Damn! How did I miss that? :\">

(Thanks Punkin!)

Nah, i meant the diagram that's imprinted on the valve body below the smudge, but yeah.

You're welcome.

Kapea

That's a diagram? I thought it was a maker's mark hanzi. Where are my glasses when I need 'em? :))

Moonshine

@punkin said: Moonshine there's an existing thread here somewhere with cooling chat in it. Could we split all this stuff off into it so it doesn't get lost?

There was no recent discussion that would fit that exact topic, so a new one it is. :)

rossco

Hey Kapea, I recon I got a headache working out your description of your cooling rig. Fairly sure we are rigged the same but I have put the splitter on the pump.

I was thinking that it does not matter whether the valve is on the inlet or outlet side of the RC, but that it needs to be on the lower of the two.

Kapea

Here is what the brass Y splitter looks like. It screws onto the hose bib. The two SD plastic hoses (blue) have barbed/garden hose adapters attached so that they can connect to the Y splitter. Everything downstream from that is push-connect. (Including the now properly oriented needle valve)

If you soak the plastic hose in boiling water for a minute or two, the plastic softens up enough to slide over the barb and make a waterproof seal when cooled - no hose clamp required ( @Smaug taught me that).

Sorry about the headache @rossco.

Myles

mine was done like this :))

Next time it will be done a bit better. Still it was functional. :D

rossco

Yeah @Kapea its the same idea.
How I keep track of flow is a couple of pieces of copper pipe in the outlet ends of the return lines.
Then I clamp them to the rim of the water reservoir above the waterline. The copper stops the clamps collapsing the coolant line. That way you can see exactly how much water is exiting the condenser and put your hand in to judge the heat. Also I use 2 cooling towers so I can shift from one to the other in 5sec so do not need to interrupt the run. No temps, flow gauges or anything like that. BTW my setup needs to be packed up and stored.

CothermanDistilling

FYI - regarding using a single pump... I have a single pump, a pump that is roughly equivalent to a march 809 that handles a 380L/8" CD for both the RC and PC, using an IBC tote for cooling water... I have a PID proportional valve on the RC and a danfoss mechanical thermostatic valve on the PC.

Mickiboi

Multi stage pressure pump, VFD and a pressure sensor. Maintain a constant pressure to both condensers regardless of the flow rate of either condenser.

grim

Grundfos makes a circulator named Alpha that is permanent magnet and computer controlled. It can run in constant flow and pressure modes. It's about $175 in the states. Also has a neat feature that will tell you the flow rate.

I have more VFDs than I can shake a stick at now. How big is that 3 phase pump?

Kapea

Of all the parameters you can control in cooling water, how is pressure relevant, especially regardless of flow?

Myles

+1 I like the simple option.

Pressurise the supply line and just add flow control to each condenser in the system. Irrigation pumps like mine can run sprinklers and drip feed systems. Mine will pump to 2200 lph, or to 11m in height. Works like a dream.

Mickiboi

@Kapea said: Of all the parameters you can control in cooling water, how is pressure relevant, especially regardless of flow?

Keeping pressure constant keeps flow consistent. You can't maintain a consistent predictable flow without a stable pressure on your supply. All chill water and cooling condenser water systems all use pressure control. If you have a system with 2 valves, as one valve opens pressure will drop. As pressure drops the flow through the second valve will drop. If you maintain 70kpa or something then the pressure at the set valve will always be 70kpa. If the pressure doesn't change then the flow can't either.

@grim said: Grundfos makes a circulator named Alpha that is permanent magnet and computer controlled. It can run in constant flow and pressure modes. It's about $175 in the states. Also has a neat feature that will tell you the flow rate.

I have more VFDs than I can shake a stick at now. How big is that 3 phase pump?

It's 700 watts at 60lpm. I have had it down to 2lpm at 100Kpa no problems. I haven't seen those grundfos pumps. Waiting on a call from my mate who works there and see what he has. Just like everyone else here I'm trying to use what I have in my shed to keep my costs down. I think those pumps here will be a lot more expensive than $175.

Kapea

If you change a valve position and maintain constant pressure flow changes. On the heat exchangers I operate, flow, temperature, pump motor amps, and runtime are all that are monitored. Cooling water pressure is irrelevant.

Head loss across screens and filters is monitored to know when to initiate backwash cycles. I guess that could be considered pressure in relative way: filter inlet = 0 filter outlet = a negative value.

Mickiboi

@Kapea said: If you change a valve position and maintain constant pressure flow changes.

I thought that's what I said? But ok

Kapea

@Mickiboi said: Multi stage pressure pump, VFD and a pressure sensor. Maintain a constant pressure to both condensers regardless of the flow rate of either condenser.

The heat capacity of water changes 1% from 1kPa to 200kPa. Pressure is irrelevant. Flow is the variable parameter that controls heat exchange.

Set a temperature to be maintained at point A (deflegmator CW outlet). Your controller will vary the frequency of the current to your motor to speed the pump up or slow it down, to increase or decrease the flow past point A, to maintain that temperature set point. As long as the pressure does not exceed the pressure rating for your system, it is not relevant.

Why spend all that money on a VFD if you're not going take advantage of what it can do?

Mickiboi

Yes

Mickiboi

You can change the flow through either condenser and by maintaining a constant pressure the change in position of one valve will not affect the flow through the other valves, no matter how many valves are in the system. Or have i been engineering and installing process control systems totally wrong for the last 25 years. I am thinking we are talking something different between us here. I have installed systems with hundreds of valves all requiring different flows for different systems. It would never be possible for the myriad of control loops to keep those flows required by the processes without keeping a constant pressure at the inlet of every single valve. The system would never stop hunting when a couple of valves open up and the system pressure drops.

Pump pressure control diagram (PDF)