Would love some more information on this, I’ve never ran passive with much success. I’m trying to avoid get another cmep pump. vacuum system, and nitrogen to solvent tank, threw product vessels into collection tank. close product side, heat collection tank and chill solvent tanks?
any help you can provide is deeply appreciated, this sight rocks!
attach a big condenser(coil works, shell/tube is best) to your solvent vessel (or just before and chill solvent too)
the gas will know how to leave your collection pot/evaporation area and race to the condenser through the hose you provide. it’s smarter than the compression pump.
Hey @GreenMachine_Consult I saw this comment you made in another thread and wanted to reply to it here.
Is there anything else (pics??) you can say about the new pumps coming out from CMEP? We are long overdue for some updates to the small/medium pump offerings for this industry.
CPS (maker of the TRS21) has had a great opportunity to remake or scale up the TRS21 to a meaningful pumping capacity but they haven’t. I remember years ago when we tried to reach out to them to offer us a larger pump and they just shut us down pretty hard.
Also, has anyone had a chance to use one of the new Master Vapor 150 XL pumps yet?
To determine the appropriate pump, first you need to determine how much heat you can add to the system. The kW of heating power will give you a rate of butane heating and evaporation.
If you don’t supply enough cfm (by means of heat) your pump won’t be working to its full capacity. I can imagine that many people in the BHO world have purchase huge pumps only to find that they weren’t providing enough heat.
Yes I agree. And to go further, you need to make sure your collection pot/evaporator setup can effectively get that heat into the solution. For a standard jacketed vessel, there is a point at which adding a larger heater will not have any meaningful effect on the evaporation rate unless you really jack the temperature up high and even that effect is limited.
I think more commonly what happens is people buy a pump (TR21 or CMEPOL) that is in fact too small for the amount of vapor they’re producing and the pump acts as a bottleneck during the high point of the bell curve of recovery. This is why we have the silly ongoing argument about which is faster active or passive. A lot of people with small systems got rid of the bottleneck by dunking their tank in DI/IPA slurry and jumped to the conclusion that passive is across the board better/faster for all applications.
In the early days not many pump manufacturers wanted to embrace our industry and the options for small pumps has been very limited.
If you could elaborate more on the heating vessel geometry that’d be rad—I assume you mean that ambient heat loss increases as the collection becomes more bulky. In that case, it totally concur, but a quick solution is pipe insulation (R = 3). You can increase the efficiency of your recovery quite substantially this way.
I am mainly referring to the Square-Cube Law which is a mathematical principle applied in a variety of scientific fields which describes the relationship between the volume and the surface area as a shape’s size increases or decreases.
This principle states that, “When an object undergoes a proportional increase in size, its new surface area is proportional to the square of the multiplier and its new volume is proportional to the cube of the multiplier.”
What this means is if you take a shape like a standard jacketed collection pot and double its size proportionally, the new surface area of the vessel (i.e. available area to be jacketed and heated) will be 2^2 or 4 times the original but the volume will be 2^3 or 8 times the original shape.
Do you see how that presents an issue? As you scale up a jacketed collection pot your ratio of liquid volume to heated jacket surface area gets worse and worse. Even if you increase your heating capacity to infinite kw’s, you will not be able to actually get that heat effectively into the solution to generate vapor.
I think a lot of people start with an 8" or 10" jacketed collection pot (or water bath with sous vide’s) and it works great but once they try to step up to 12" or larger they’ll notice that the heaters, even if made larger, are holding stable temperature but recovery rate has stayed that same or even gotten worse. This is because of the square-cube relationship and leads some people to conclude that skinnier collection pots create more vapor.
This leads to a conundrum in the sense that a skinnier collection pot is easier the get heat into the liquid pool using a standard heating jacket but the smaller exposed liquid surface area acts as a limiting factor to vapor generation. Once you try and step up to a wider collection pot which should in theory have more vapor production due to the larger exposed surface area of the liquid pool you hit the square-cube law and can’t as effectively get the heat where it needs to go and vapor generation suffers.
This is where internal heat exchangers come into play.
Have you ever heard of an internal calandria? They are typically used in brewing applications where they have a large, wide vessel filled with wort they need to boil. It’s basically a tube-in-shell inside the vessel.
You can also set this up as an external calandria (heat exchanger) with pumps, which is a good drop in solution that I suggested to @Roguelab to speed up vapor generation in his large jacketed vessels.
Do you see how adding a pump and external heat exchanger like the picture below increases the surface area available for heating the solution but does not significantly increase the volume of liquid that needs to be heated like with the square-cube law?
I am currently having a 24" wide collection vessel made up that has just the lower dome part jacketed, not the sidewalls. Then I have two horizontal coils that drop in from the lid and extend down to just above the height where the jacket cuts off so they’re always in contact with liquid until the heated jacket starts.
I see a lot of people currently using vertical drop in coils but the problem with that is as the liquid volume drops off there is less and less surface area of the coil in contact with the liquid and vapor generation falls off. I’m hoping the horizontal coils solve that issue.
I appreciate the well-constructed response. Thank you for mentioning the square-cube rule. It’s true that the ratio of effective heat transfer surface area to vessel volume decreases as the tank gets larger. However, what is the mechanism by which this disallows the same rate of evaporation?
In my mind it would be reduced heat transfer efficiency—but not to the extent that supplying infinite kWs won’t fix it.
It’s a matter of calculating reduced heat transfer efficiency, and determining again what power is needed to evaporate at the desired rate. I think, especially at our scale, this is a non issue, because you can provide 25kW of power with a $500 water heater.
What remains is calculating the volumetric evaporation rate as a function of surface area and heat—can’t think of exactly how at this moment, but I’ll check back in when I figure it out
Only down side is heat is allowed to certain extent
I start seeing scourching spots when jacket is heated to over 70C
Not burned but sticky
I am having better results with
An pre collection pot that is pressurized by nitro to 6 bar
And sprays in a deplegmator that ends in the evaporation collection pot
So once the liquid comes in it gets heated by the deplegmator before entering the jacketed collection pot
I have the deplegmator set at 70C
But deu to short contact and evaporation cooling the water exits the deplegmator at 63C
But the 4"x 24" deplegmator produces a lot more vapor than the jacket
And I can almost tune it to the 12cfm of the corken 491
Making my collection pot stay almost empty
could you please let me know what type of water heater you use?
thanks
i am curious as to what water heater you are using that is 24kw for $500…thats a deal!
what about multiple collection pots that are smaller than those big purge lab ones? i have a t291 corken and i am curious as to if it would be better —- paired with a 48kw heatet
Here’s a 27kW tankless heater for $355 bucks…
why does it take 3 50amp breakers? is it 3 different heating elements at 9kw per?
Blockquote
The picture with the wort kettle is similar to what is called a pump around section in an atmospheric distillation tower. The purpose of this is to have better control of the process parameters for efficient production while wasting minimal thermo energy inside of the system.
Also horizontal coil wont be need you can use tubing. Such as a kettle re boiler or single pass shell & tube. dang just imagine if those tubes were nozzle sprayed. hmm one might say this is horizontal Falling Film 
I hit 1 -2 lbs per min depending on water bath temp with regular ice 50 feet of 3/8 " coil with 70/30 iso/ pro with 4 trs21 pumps . I think i could push it even more by reducing bottlenecks in my system or using dry ice . Cost me 5k best option for the price in my opinion . Or just cough up 8k for a old MVP . The TRS21 pumps rock you just need 4-8 of them lol but for 1000-1200 its really not that bad . Even 2 preform pretty well IMO for small systems . I rocked a singular pump for my first 2 years on a 5lb CLS and it was ok . I think 1 trs21 is basically close to a CMEP .
so many breakers due to low voltage.
all of these are divided internally into a bunch of heaters and a little shell+tube
Word on the street is you’ve never run a CLS in your life yet you giving endless advice on multiple threads on various aspects of hydrocarbon extraction and remediation. You obviously have a brain based on good advice given in other threads and other topics and you obviously good at distillation but CLS theory and reality very different mate and I’d dare say what you doing is careless and potentially extremely dangerous considering you’ve never actually done it. What gives? This isn’t cold ethanol… You trying to look cool or what? Anyone can regurgitate information gleaned off the internet… but why pretend 
Then again you think DME is better than hydrocarbons so yeah who knows what’s real…
Huh talking to me ??
Dme beter i Saïd that ?
Never ran a closed looop ??