Beesource Beekeeping Forums banner
1 - 20 of 38 Posts

·
Registered
Joined
·
18 Posts
Discussion Starter · #1 ·
I need to know which vap machine is best for mites ? Who has them , cost ? Please ! Thank You for your help. Sarah
 

·
Registered
Joined
·
18 Posts
Discussion Starter · #3 ·
We are just getting started but would like to go ahead and get vap machine . Not to interested in a wand. Thank you so much for your time and information. It is greatly appreciated.
Thank You , Sarah
 

·
Moderator - In Memorium
Aylett, VA 10-frame double deep Langstroth
Joined
·
6,882 Posts
JoergK is Biermann
Rick is RAST
Another whose name I can't remember is Jbee6000
Start a private conversation with them right here on Beesource.

You are right to get a band heater style vaporizer as, in my opinion, they do a much better job at dispersing the OAV within the hive.
 
  • Like
Reactions: Sarah71618

·
Registered
Joined
·
7,046 Posts
The band heater type completes a treatment in a fraction of the time taken by a wand or tray type unit. Like only a tenth the time and will work on all types of hives.
 

·
Moderator - In Memorium
Aylett, VA 10-frame double deep Langstroth
Joined
·
6,882 Posts
band heater ? don't laugh at me , I am new to this.
It is the style of heating element used to sublimate the OA.

If you have a few hours...

 

·
Registered
Joined
·
46 Posts
I saw somewhere that if you heat OA up to much it will transform the OA into Formic acid which won't do much.
I am thinking from my experience that the OA would have to be contained in an escape proof container to be able to heat it to that point. It sublimates into a gaseous state that escapes through the nozzle before it can reach formic acid temperature. Much like trying to heat water past the boiling point without a pressure cooker. With that opinion stated, I also feel it is highly likely that trace amounts of formic may come out at the end of the treatment.
 

·
Registered
Joined
·
7,046 Posts
I am thinking from my experience that the OA would have to be contained in an escape proof container to be able to heat it to that point. It sublimates into a gaseous state that escapes through the nozzle before it can reach formic acid temperature. Much like trying to heat water past the boiling point without a pressure cooker. With that opinion stated, I also feel it is highly likely that trace amounts of formic may come out at the end of the treatment.
Yes;
It would require either pressurization or discharging past a very large and very high temperature radiant heat surface to accomplish such breakdown conditions. Not going to happen in either these band heater or tray type OA evaporators.
 

·
Registered
Joined
·
2,134 Posts
There is a lot of confusion on this, and I stay pretty confused with it. My understanding is that oxalic acid dihydrate sublimates at a temp of 157 C, but if it reaches 189.5 C, it actually degrades to formic acid and carbon monoxide. So there is a "goldilocks" range where you can get too cold and you can get too hot.

The confusion primarily starts for me in the default temp settings of many of these commercially produced applicators. The Provap 110, for instance, comes preset to maintain a temperature of 230 C. In my simple mind, when I drop my OA into the bowl that is heated to 230C, I have overshot the goldilocks range and am gassing off my OA as formic and carbon dioxide.

What I am told through message boards and internet wisdom, but through no scientific paper that I have seen, is that even though the bowl is heated to 230C, once the OA hits the bowl, it either (1) absorbs the energy, thus effectively dropping the OA into the goldilocks zone, or (2) will not heat the OA to 230C upon hitting the bowl because it will gas off before the OA can reach the degradation point, or (3) a combination of (1) and (2).

I would like to see something other than a message board post or YouTube video that seems to scientifically demonstrate this principle, but I have not found anything. So I continue to operate my ProVap 110 a little on faith and faith is not something I have a lot of.
 

·
Registered
Joined
·
7,046 Posts
PSM, it is not an easy concept to explain. I got tired of the discussions about it here years ago. Heat transfer into a solid or liquid is very efficient. Heat transfer in absolute terms (like Btu.s per unit of weight) from a heated surface into a gas is not efficient. As the contact liquid or solid is gassified it is propelled rapidly and continuously away from the heating surface due to the immense increase in volume. As soon as it leaves contact with the hot surface, it then is subject to being heated only by radiation. Radiation through a gas leaves it virtually unheated. Think sunshine on a cold day. The air is still cold despite the suns Temp. in hundreds of thousands deg. F.

As long as the vapor is free to move away from the heat source it will rapidly do so. If you pressurize it you can hold it in contact with the heat source and its temperature can increase above its atmospheric pressure change of state temperature. When the last of liquid (or solid in OA case) is vaporized and gone off, only then will the temperature in the vessel rise to meet that of the heating surface. Only the last few cubic inches of the charge will be there at that time compared to the 3 or more cubic feet of charge that has been driven off at the conversion point temperature. It just does not get hotter than that in there till it is all gone, then at that point the internal temperature in the vessel can rise to the temperature of the vessel wall.

I have sat in classrooms of wannabe steamfitters and plumbers who were attempting to understand it. I got the certificate but seldom really have had to go back and try to explain it. Some things just are easier to accept on faith!

Edited for clarity
 

·
Registered
Joined
·
137 Posts
Bla, bla, bla ........as a hobby beekeeper with 4 hives, it works for me!!!!!
If you think you have an overheating problem, reduce the flame of the blow torch, or move the flame further away, simple, priceless!
 

·
Registered
Joined
·
2,134 Posts
Thank you Frank. That is as good of a description as I have ever heard. And I give you a lot of credibility here, so my faith is improving.
 

·
Registered
Joined
·
427 Posts
I agree with Frank and I have read it somewhere...Maybe Randy Oliver at scientificbeekeeping,com. Faith I have.
 
1 - 20 of 38 Posts
Top