Town Water vs Bore Water

Hi guys,

I have a Baby Dragon. With town water I was lucky to get a drip, just flowed. I switched to bore water and now it's refluxing like crazy and I can control the flow. The water temps are similar, I figure it is the minerals in the water.

What are your thoughts?

Regards,
Richy

Comments

  • I highly doubt it.
    My guess is the different pressures gave way different flow rates.
    Did you actually measure the water flow rate for each? Stopwatch and bucket style?

  • It's temp or pressure or both.

  • The bore water is same temp +- 0.5c and flow rate is less then town water , I can see the flow rate. both washers where running at 150 volts.

  • or a condenser full of air

  • edited May 2016

    Less flow rate = higher temp = more take off.

    If you fit a Thermotee on the exit of the reflux condensor water you'll be bale to monitor and record the exit water temperature.
    That will let you have much more control over the takeoff rate.

    StillDragon Australia & New Zealand - Your StillDragon® Distributor for Australia & New Zealand

  • edited May 2016

    The other consideration with using well/bore pump - do you have a charged pressure tank after the well pump (usually the case)?

    It's typically to have a 20psi differential between the pump demand and pump shutoff pressure points, at least here in the states. This is to prevent short cycling of the pump. The tank afterwards is there so that small water usage doesn't cause the pump to trip, again preventing short cycling. But what it will cause is long-waver of pressure based on constant water flow.

    If this is the case, it may be that your flow rate is wavering, and might be making it tough to dial in.

    Starts off fine, as the tank is discharged the pressure falls, slowing the flow rate, you dial the flow higher to get reflux dialed in, and again - all the sudden you get down to the cut-in, flow rate is at the slowest, and the pump kicks on and re-pressurizes the system to the cut-off point - and now flow rate is at it's highest for the valve position - reflux goes crazy.

  • edited May 2016

    Just trying to float plausible ideas - the mineral content of the water is so small that it wouldn't really make any kind of appreciable difference in the heat transfer ability.

    In most cases, the high mineral content would - long term - cause solids build-up on the tubes of the condenser - making heat transfer less effective. For hobby use, this would probably take years of regular use.

  • edited May 2016

    Two things:

    I use rainwater pumped exactly as @grim described with a pressure tank and pressure switch - only instead of being pumped out of a well it's pumped out of a 20,000 gallon rainwater cistern. The pressure switch on the pump is set to turn the pump on at 40psi, and off at 60psi. To prevent the flow variation in my deflegmator due to this change in pressure (up and down) I have installed a pressure reducing valve set at 30psi on the cooling water feed line to my deflegmator. The deflegmator sees a constant 30psi and the flow is steady. Fixed value pressure reducing valves can be found on the cheap in the irrigation section of your local hardware or big box hardware store.

    Well water is prone to being hard. Hardness in water is almost all calcium and magnesium ions (technically, hardness is any dissolved divalent cation). Calcium and magnesium ions are inversely soluble. This means the saturation concentration value of hardness ions reduces as the water temperature increases. There is a boundary layer effect on the water immediately up against the metal of the vapor tubes. If your cooling water is hard there is a good chance you will scale up the shell (cooling water side) of your condenser. Hardness scale is a good insulator. Scale on the cooling side of your condenser will cause a significant drop in heat flux.

    If you recirculate your cooling water you can add an antiscalant to your cooling water to help prevent scaling up your condenser. Or, an overnight soak in a dilute citric acid solution, or a dilute EDTA solution will remove the scale.

    Rainwater has 0 hardness. Lucky me.

    I'm more like I am now than I was before.

  • Nothing to do with the water. It is the lower voltage input from the DIY control .

  • Had to be an external factor because as long as there is no scale up the difference in water would be unmeasurable.

  • Moral of the story is buy a DIY control unit , save water and power !

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