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Separate cooling on Dash ?

In a while I will replumb my cooling on my Dash 1.
I 'll split the output of the dephlegmator. between a 1/2" needle valve(full reflux) and a 1/4 metering valve(during take off).
So I hope to fine tune even better my cooling temp off the dephlegmator.
Now I read somewhere that it is good to control also the temp. of the product condenser. If i remember well it was about higher temp of condensed product is beneficial for escaping the higher alcohols.
If so, i would separate my cooling lines.
What are your thoughts ?

Thanks,

M-

Comments

  • I run my product condensor (PC) flat out through the entire run. Why? - 1 less thing to fiddle with - I'm from the KISS school. - i feel that a fast flow means that the water exiting the PC is cooler than if I reduce the flow. That is beneficial to me as I run a recirculated coolant tank and the fast flow keeps the reservoir cooler longer

    Again using the KISS principle, i always air my new make spirit for a few days to allow any higher order alcohols to evaporate off.

  • CD, what do you mean by KISS school ?

  • Keep It Stupid Simple KISS

    It is what you make it!

  • @crozdog said: I run my product condensor (PC) flat out through the entire run. Why? - 1 less thing to fiddle with - I'm from the KISS school. - i feel that a fast flow means that the water exiting the PC is cooler than if I reduce the flow. That is beneficial to me as I run a recirculated coolant tank and the fast flow keeps the reservoir cooler longer

    Again using the KISS principle, i always air my new make spirit for a few days to allow any higher order alcohols to evaporate off.

    Hey Croz, how many L/G in the holding tank? I'm thinking of going that route.

  • 160-170l. I also run the return line into a radiator with a fan on it before the water returns to the reservoir

  • Do you add anything to the water to keep algae and stuff from growing?

  • nah, just change it every few weeks....thats the theory anyway haha ;-)

  • edited October 2013

    @nvnovrts said: Hey Croz, how many L/G in the holding tank? I'm thinking of going that route.

    I run with a 1000lt "shuttle" tank on a pallet with submersable pump rated at 900w or 14000 lt/hr and have the outlet setup with a pressure bypass loop, then the stills inlet water side is split in two, product condenser flat out- no valves etc, the reflux with the only control valve, on the outlet side. My water can creep up in temp a bit when doing 2 runs in succession, but I've yet to really test this in a summer temp, only mild /winter temps so far. My next runs will be this weekend, expecting 30-35 degree days so I will take some notes, once summer hits my shed reaches 40-45 degrees so the starting temp will be a lot higher. I do have a bypass/refill system in place if required, (simple tap/splitter) that is I can direct the stills outlet flow to the the lawn area and run a garden hose (coolish water) into the tank

    @Lloyd said: Do you add anything to the water to keep algae and stuff from growing?

    My mate tests my water every now and again and uses spa treatment and I don't have issues with smell/mould etc.

    Fadge

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  • Fadge really nice shed from what i could see... lotsa room...

  • edited October 2013

    @FullySilenced said: Fadge really nice shed from what i could see... lotsa room...

    +1 on that. 45 is a bit warm for my likes. Are you using any type of radiator/mister on the return loop?

  • 45C or 113F kills people.

    Like @punkin's Thai Terror :\">

  • @crozdog said in 2 different posts: I run my product condensor (PC) flat out through the entire run. Why? - 1 less thing to fiddle with - I'm from the KISS school. - i feel that a fast flow means that the water exiting the PC is cooler than if I reduce the flow. That is beneficial to me as I run a recirculated coolant tank and the fast flow keeps the reservoir cooler longer.

    160-170l. I also run the return line into a radiator with a fan on it before the water returns to the reservoir

    Hi all. First post and I hope you don't mind me jumping in. I am just getting into the distilling hobby, but have a Systems Engineering background and have a few comments.

    The power removed from the Product Condenser will be the same regardless of the flow rate, assuming the product temperature is the same. For example, if you are running at 4 liters per hour of 180 proof product, the vapor temperature should be 78.5 degrees C and you need condense 3.6 liters of Ethyl Alcohol and 0.4 liters of water from vapor. You also need to reduce the temperature of the resulting liquid from 78.5 C to, for example, 30 C.

    Liquefying the Ethyl Alcohol requires removing 660 Watts and 251 Watts for the water. Reducing the temperature to 30 degrees takes another 93 and 23 Watts for Ethyl Alcohol and Water respectively. This is a total power of 1027 Watts.

    Water needs 4189 Joules per liter to increase temperature 1 degree C. Each minute will produce 1027 watts times 60 seconds / 4189 equals 14.7 Degree Liters / Minute

    Therefore, (Assuming in all cases the condenser design supports this configuration.):

    0.5 Liter per minute will increase in temperature 14.7 / 0.5 = 29.4 Degrees C

    1.0 Liter per minute will increase in temperature 14.7 / 1.0 = 14.7 Degrees C

    2.0 Liter per minute will increase in temperature 14.7 / 1.0 = 7.35 Degrees C

    Fast flow and use of a radiator are somewhat inconsistent since the effectiveness of a radiator is directly dependent on the temperature difference between the environment and the liquid being cooled. The larger the difference, the more energy is transferred to the air.

    If you reduce the flow until the product temperature just begins to rise, you will maximize the outlet temperature of the coolant, therefore improving the efficiency of the radiator, without impacting your product.

    Without the use of a radiator, the temperature of your 160 Liter coolant reservoir (for the 4 liter per hour product rate being examined) will be 14.7 (Degree Liters / Minute) times 160 Liters = 0.092 Degrees / Minute

    Free flow tying. Sorry no time to refine...

    Flyer

  • edited October 2013

    @nvnovrts said: +1 on that. 45 is a bit warm for my likes. Are you using any type of radiator/mister on the return loop?

    @Lloyd said: 45C or 113F kills people.

    We get 45+ degrees every summer, and add a bit for the tin shed and its bloody hot on some days. I have a temp strip on the tank but it only goes to 38 !

    @Flyer_Tuck perhaps you are right with those calcs, it may make sense to actually slow the water flow when required?

    Q. Using a non radiator return water tank system, is it better to run the water flow faster or slower in relation to the tank heating up time frame?

    I've read your post twice, but my head is struggling to work out the "better" way to run.

    Fadge

  • 30C (86F) is a bit warm for product temp. The alcoholmeters are calibrated for 20C (68F) and surely it would evaporate less at the lower temperature.
    Would that be a bad thing? I don't know. A collection jar sitting at 20C vs 30C might not be so bad if it tended to drive out the higher volatiles - the very reason we air out the product.

    Using a non radiator return water tank system, I'd think a slow flow would be better than a fast flow since you're putting hot water on top in the tank but pulling from the bottom. You'd want as little mixing as possible to make the cooler bottom water last longer.

  • @fadge said: Q. Using a non radiator return water tank system, is it better to run the water flow faster or slower in relation to the tank heating up time frame?

    It does not matter, from a pure energy standpoint. The 160 liter tank in the above example will rise in average temperature at any flow rate with a 1027 watt load.

    Lloyds observation is important. With lower fluid speeds, mixing when re-entering the tank is minimized and allows the hot water to 'float" on top of the cold.

    In non distillation systems, I have always run temperature control systems with the lowest flow rate that meets the control objectives. In industrial systems this allows lower pump size with lower power use, smaller pipes, etc.

    For this type of system I would also run at the lowest rate that knocked down the vapor and cooled the product to my desired temperature.

    I am designing my system and plan to over build the product condenser specifically so I can run the water slowly and heat the water to a higher temperature. I'm also planning to experiment with continuous distillation as a stripper and this requires more water vapor to be condensed.

  • @Flyer_tuck said: It does not matter, from a pure energy standpoint. The 160 liter tank in the above example will rise in average temperature at any flow rate with a 1027 watt load.

    Should be:

    It does not matter, from a pure energy standpoint. The 160 liter tank in the above example will rise in average temperature by 0.092 Degrees per minute at any flow rate with a 1027 watt load.

  • Flyer, thank you for the information. I wanted to make sure I was using it correctly. If a person were attempting to condense and cool 10 L/h @ 180 proof, they would require 2567.5 Watts resulting in a temp change of the cooling water in a 1000 L tank by .037 degrees (C)/minute correct?

  • Yes. You have 1000 / 160 = 6.25 times the water and 10 / 4 = 2.5 times the load so the temperature will increase by 2.5 / 6.25 = 0.4 times as much. 0.092 * 0.4 = 0.0368 degrees C / Minute

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