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Thread: ProVap110 video

  1. #41
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    Default Re: ProVap110 video

    OA decomposes to form formic and carbon monoxide at 372f (about 190c) . In 2 grams, there is not enough formic formed to kill mites and there is not enough carbon monoxide to hurt the bees. When we were using the Varrox (and the Sussex study did the same) we just kept the Varrox hot the entire time (not cooling down between hives, just adding OA and moving the wand into the hive (of course wearing a respirator the entire time). We found (as the Sussex study did) that the mite kill was just as effective using the Varrox hot as letting it cool down in between hives, adding OA inserting the wand and letting it heat and vaporize.

    The ProVap temp is set to 230c which is 446f. Leaving the Varrox "hot" the entire time well exceeded 230c! When developing the PV110, we just kept increasing the temperature till we got to point where the OA completely vaporized, the stem dig not clog and mites were killed. Need to know also that the temp of PV drops to about 210-215c when the OA drops into the bowl and slightly cools as it makes it way thru the stem, into the hive. So, I'm GUESSING it's not too much above what Medhat's temp of 170 when entering the hive.

    Now, I can't explain the "why" when the temps are so high that it "works," (as it flies in the face of all we know about sublimating OA to kill mites) but it does (just as in the Sussex Study).......
    Last edited by snl; 02-26-2017 at 08:43 AM. Reason: Add'l info
    http://OxaVap.com Your source for the ProVap 110
    OA Vaporizer. The fastest vaporizer on the market!

  2. #42
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    Rader, Greene County, Tennessee, USA
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    Default Re: ProVap110 video

    *My opinion* is that its likely that the temperature displayed is not necessarily the temperature of the oxalic acid itself as it sublimates. The displayed temperature is read from a thermocouple, and -presuming the thermocouple is reasonably accurate- is the temperature of the material the thermocouple is in contact with.

    Consider a pan of 'boiling' water on a stove. We *know* the steam boiling off is at 212 degrees F, but some of the water in the pan is less than 212 degrees, otherwise it would also be steam. And the bottom of the pan is hotter than 212 degrees, otherwise it would not be adding heat to the water. And the stove element is hotter still. So how would you build a thermocouple into the stove to measure the exact temperature of the steam boiling off?

    I'd say that would be a very difficult task unless perhaps one were to suspend a thermocouple directly above the water, but always fully surrounded by the steam.

    The thermocouple in theProVap faces a similar challenge.
    Graham
    USDA Zone 7A Elevation 1400 ft

  3. #43
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    Feb 2012
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    St Thomas, Ontario, CA
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    Default Re: ProVap110 video

    Hi Ben
    I am lucky to have Anchem in London. One of my guys lives very close so he swings by and picks it up. After looking at their site it seems they would ship to you.
    Albert

  4. #44
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    Default Re: ProVap110 video

    I have two more yards to do and that will finish my third round. I am going to turn up the temperature and see what drops. I am not expecting much. Most of the mites are already dead.
    Thank for the advise. I find it hard to go against beliefs that I have held for so long but I think it is called learning.
    Albert

  5. #45
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    Default Re: ProVap110 video

    Ya but science is science. Which means are we actually sublimating the Oxalic Acid or are we simply cooking it off into another decomposed form
    Convenience is not a beekeepers asset

  6. #46
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    Algoma dr. Ontario, Canada
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    Default Re: ProVap110 video

    Quote Originally Posted by Smoke'm View Post
    Hi Ben
    I am lucky to have Anchem in London. One of my guys lives very close so he swings by and picks it up. After looking at their site it seems they would ship to you.
    Albert
    Look at Alphachem in Toronto. I was not happy with the shipping rates but their price is good if you pick up.
    Frank

  7. #47
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    Default Re: ProVap110 video

    Quote Originally Posted by Ian View Post
    Ya but science is science. Which means are we actually sublimating the Oxalic Acid or are we simply cooking it off into another decomposed form. Convenience is not a beekeepers asset
    True, but mite drops are........
    http://OxaVap.com Your source for the ProVap 110
    OA Vaporizer. The fastest vaporizer on the market!

  8. #48
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    Default Re: ProVap110 video

    Quote Originally Posted by snl View Post
    True, but mite drops are........
    Too many ???

  9. #49
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    Default Re: ProVap110 video

    Quote Originally Posted by snl View Post
    When developing the PV110, we just kept increasing the temperature till we got to point where the OA completely vaporized, the stem dig not clog and mites were killed.
    snl - Interesting info on the development and use of the Varrox and Provap. It sounds like the working temperature of 230C for the Provap was determined by trail and error based on finding a temp that prevented the vaporized OA from re-condensing before it could exit the nozzle.

    I find that I do get a small amount of OA re-condensing in the Provap nozzle, and I get some OA re-condensing on frames within an inch or two of the nozzle. The unit is easy to use and I get great mite kills, but, if possible, I would like to reduce the amount of OA that re-condenses before it is distributed throughout the hive. I know the set temperature of the Provap is adjustable. Would you suggest I go up in temp, or has your experience shown that 230C a relatively firm upper limit that shouldn't be exceeded?

    TIA
    --shinbone
    (7th year, 10 hives, Zone 5b, 5500')

  10. #50
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    Default Re: ProVap110 video

    Quote Originally Posted by shinbone View Post
    I know the set temperature of the Provap is adjustable. Would you suggest I go up in temp, or has your experience shown that 230C a relatively firm upper limit that shouldn't be exceeded? TIA
    Me, I'd leave it set at 230 as we have found that to be optimum.
    http://OxaVap.com Your source for the ProVap 110
    OA Vaporizer. The fastest vaporizer on the market!

  11. #51
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    Default Re: ProVap110 video

    Roger that. Thanks.
    --shinbone
    (7th year, 10 hives, Zone 5b, 5500')

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