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Krimelte received lot of interesting and innovative ideas from our last challenge, which is the reason why they have decided to do it again. This time they need you to design a foam heater that matches their standard aerosol gun. Good luck everybody!
The content of OCF (One Component Foam) aerosol can consists of a mixture of polyurethane prepolymer and liquefied gases. As it escapes the aerosol can, the prepolymer reacts with air moisture and instantly appears as a foam.
The foaming process can be problematic at the cold temperatures as gases lack the power to expand and the chemical reaction become slower. This is the reason why aerosol cans work better in warmer environments, but this is not always possible.
Thus, Krimelte needs your help in developing an innovative heater that can be mounted on their OCF gun nozzle that helps to heat up the foam that already is out from aerosol can.
Thank you to Alan Baird and Zack Haubach for uploading the CAD files of Aerosol Can and Foam Gun.
Heater could be either on the gun or between the aerosol can and gun
Uses 220V AC as energy source
Material heat capacity approx 1700 J/(kg•K)
Heater needs to be constructed from standard electrical parts available on the market with a reference to the supplier or manufacturer on the model description
Must heat up the mixture from 0°C to 20°C and should not overheat
Normal foaming speeds 200-400 g/min
Must be safe for the user
Easy access to cleaning with chemicals (e.g. acetone)
Winning design will be chosen based on the design and functionality
The competition is open to everyone
Team entries are welcome
You can submit several designs
Only models uploaded to GrabCAD library will participate in the competition
Tag your model with “foamheater”
Privately uploaded models need to share access to jaan.puusaag@krimelte.ee, meelis.klimov@krimelte.ee and kaspar@grabcad.com
Privately uploaded models need to be made public after the competition deadline
Models can be done in any CAD software as long as STEP or IGES files are uploaded
Competition winner will be announced during 4 weeks after the end of competition but still asap
Cash prizes of $2100
$1000
$500
$300
$200
$100
GrabCAD T-Shirt
GrabCAD T-Shirt
GrabCAD T-Shirt
GrabCAD T-Shirt
GrabCAD T-Shirt
The winner will be selected by a joint jury of Krimelte and GrabCAD and announced on the GrabCAD blog.
Krimelte OÜ is a production company, based on Estonian capital, that is specialized in joint sealants and insulating foams. The company was founded in 1994 and the production in Estonia started in 1998.
Krimelte OÜ had made a quick progress from a retailer to one of the leading European producers. By today, our market involves over 40 countries from the EU up to Japan.
Jaan Puusaag
Meelis KlimovHave an awesome idea for this competition? Want to win cool prizes? Sign-up now to upload your entries.
If you don't receive the email within an hour (and you've checked your Spam folder), email us as confirmation@grabcad.com
61 comments
Mohomed Nusry about 13 years ago
Nice challenge!
Hope to take a part in this challenge. But, I think some more information required in order to start designing the heater.
* Dimensions of gun and aerosol can (or a CAD model of them), to determine the size of the heater unit it can hold.
* The material properties (conductivity) of the gun walls, to calculate the heat transfer rate (if someone is going to design the heater on the gun).
* Is the mixture needs to be exactly 20°C when passing the heater, or can it be any temperature between 0°C to 20°C?
(I'm asking this because I can't understand the term in requirements.)
PAX about 13 years ago
I too agree to Mohomed Nusry. The info given is too vague to even start the work. Although some ideas can be sketched, it is not possible to do a cad without some specific infos.
Dragan Beljan about 13 years ago
Very Interesting competition!
Romano Gaspari about 13 years ago
we really need a lot of additional info. the dimensions of the aerosol can attachment and gun cad file. another question I need to submit is about the power: 220V AC... it means to wire the gun to electrical wall outlet. this is very a serious problem for handiwork
Stephen Nyberg about 13 years ago
Could a battery be used if the heater is on the gun and could the canisters be heated separately and used that way before they cool back down?
Stephen Nyberg about 13 years ago
If the can is too cold, the solution will not leave the can to be heated in or before the gun.
Vadim Doman about 13 years ago
It could be nice to have a CAD file of a gun, which attaches to the can and can itself as well would be useful.
Manoooze about 13 years ago
Hi,
The competition design is very interesting but , like said the other persons, it's impossible to do a good job without the link of a CAD design of a Krimelte's can and a Krimelte's gun. .. Sorry for my English : I'm French ;-)
DaSilva about 13 years ago
yes, I agree
Indrek Virro about 13 years ago
An option is to buy the canister and gun from the store, because their our market involves over 40 countries from the EU up to Japan.
teigan about 13 years ago
oh, so in reality, the contest is just a front to sell a few cans of insulation and applicator gun. interesting marketing ploy.
James Allen about 13 years ago
Interesting project, but again, we need CAD models of the gun and can, and materials they are made of, otherwise this won't work. I live in New Zealand (Australasian Continent) we cannot by this brand anywhere, so how do you propose we design anything accuratley.
paul about 13 years ago
The problem lies in the latent heat of evaporation of the propellant in the can. The can itself need heat input through the walls during operation (usually through ambient heat on a warm day - 20 deg C). On cold days this is not available. Heated jacket would be required to operate properly on cold days. I don't believe their idea will work anyhow.
Could be wrong..I don't know everything.
Michele Gorra about 13 years ago
PENOSIL GoldGun 65 is rated to use from +5°C (http://www.wolfgroupweb.com/uudiskiri/2011/1/PENOSIL-Gold-Gun-65-Plus-All-Season-TDS_eng.pdf), so we will assume that is no problem with gases in aerosol can until air temperatore does not fall below that limit; i think that the problem with the latent heat of the gases it occurs when the gases themselves trying to expand at the end of the nozzle's gun.
Michele Gorra about 13 years ago
..and, please, a solid CAD model of the gun (even not the same gun depicted) would be very appreciated :)
Romano Gaspari about 13 years ago
may I suggest to change to a portable heater station for few cans? I think 2 or 3 cans at once will be sufficient
teigan about 13 years ago
a basic rule of urethane foam use is to wait for a day when the ambient temperature is right. even if you were to heat the constituents prior to leaving the mix tube, it would not cure properly and the results will be lumpy, with unevenly dispersed air bubbles.
Saige about 13 years ago
Penosil make winter foams that are rated for -18°C to +30°C. So that would lead me to believe the foams will cure correctly at those temperatures.
And we definitely need models of the cans and the applicator gun.
Michele Gorra about 13 years ago
1000USD extra prize for the best foam gun model?
Zack Haubach about 13 years ago
Okay I just uploaded a 3D drawing of the gun shown above, I didnt include the can or the part that allows the can to be attached because I ran out of time this morning though Im sure I'll be able to upload it later. It should be to scale as I spent a good hour going over measurements and scaling as best I could based on a photo. I hope this helps, Krimelte Foam Gun
teigan about 13 years ago
if pensoil makes foam rated for -18°C as Saige claims, then why do we need a heating attachment at all? the foam spends negligible time in the gun tube. urethane cures to working strength over a period of days during which time it must fight gravity.
Vishal G Chipkar about 13 years ago
any one can let me know that exactly what we have to model ?
i think a Gun right or a aerosol can humm ?
Zack Haubach about 13 years ago
I just updated my model to include the piece which allows the can to attach to the gun. Here's the link Krimelte Foam Gun
Michele Gorra about 13 years ago
Thank you Zack! I have just uploaded a one liter aerosol can (Penosil 1000ml aerosol can), the threaded adapter is roughly approximated, and needs some fillet. And definetely not threaded :)
Meelis Klimov about 13 years ago
I think this additional information could help:
Sometimes preheating aerosol cans is not possible, or is too time consuming, and it would be better to heat the foam prepolymer „online“. For this we need a heat exchanger, which can be mounted on normal OCF gun, for preheating of the prepolymer mixture, prior to foaming
Normal foaming speeds are 200-400 g/min
seghier khaled about 13 years ago
i have question ? we recreate the same model in photos or we create new design ?
Kaspar Kiis about 13 years ago
Please use the models by Alan Baird and Zack Haubach to design your concept. Click on "Download Specification" button to get both of them.
Zack Haubach about 13 years ago
Okay, based on everything here it seems like the best option is to heat the spray foam will its traveling through the gun. However to ensure that any design will actually work we need to ensure the foam will be heated in the approximately 14 centimeters of the barrel during which time its moving (I'm assuming at the 200-400 g/min stated above, please correct me if that's wrong). To that end we need the right equation which I think I've found but I'd like to have some input about whether or not it's correct.
This is what I found online
The mean heat transfer can be expressed as
q = cp dT m / t (3)
where
q = mean heat transfer rate (kW (kJ/s))
m / t = mass flow rate of the product (kg/s)
cp = specific heat capacity of the product (kJ/kg.oC) - Material Properties and Heat Capacities for several materials
dT = change in temperature of the fluid (oC)
Please let me know how wrong this is and help steer me in the right direction.
Tufan Unal about 13 years ago
Aerosol cap and gun is not suitable for each other and is not same as photo.. Is there any exact model for this case..
Alan Baird about 13 years ago
Hi Zack and All
You are almost there with the formula the only thing I can see wrong is Q = Energy not mean heat transfer rate, but energy in Joules per sec and as 1J/sec = 1 watt by using this formula you will get the heater capacity required to achieve the results required by Krimelte. I have posted a PDF file explaining the procedure to calculate the heater capacity to achieve the temperature change required.
Kind Regards
Alan Baird
Alan Baird about 13 years ago
Hi Tufan
There are no exact models of either, the aerosol container or the foam gun, you can change the dimensions of at least the aerosol model to suit Zachs model or vice versa or draw your own
The dimensions of these items are immaterial to the challenge and the important criteria are in the challenge brief,...... for example the specific heat, the mass of material delivered/ minute and the temperature change , and of course your design concept of the best way to achieve Krimelte,s requirements.
I understand that a good designer will always ask questions but sometimes we need to make assumptions !!!! and use what we have to achieve a solution.
Kind Regards
Alan Baird
Kaspar Kiis about 13 years ago
Alan and Zack are on the right direction- Krimelte is looking for a solutions to heat the foam when it is actually out from the can not heating the can itself. Heater could be either on the gun or between the aerosol can and gun as said in the requirements.
Zack Haubach about 13 years ago
Hi Alan
You said you posted a PDF though I have been unable to find it, would you mind telling me where it is. Thank you for the help it's very appreciated.
Alan Baird about 13 years ago
Hi Zack
if you click on view all or click on model feed last entry name: Other thats the PDF
Alan
Zack Haubach about 13 years ago
Hi Alan
Thank you, I hadn't thought to check that.
Jason Weber about 13 years ago
does anyone know if there is a reason the can cant be heated first?
Alan Baird about 13 years ago
Hi Jason
As stated in a previous comment from Meelis Klimov from Krimelte
" I think this additional information could help:
Sometimes preheating aerosol cans is not possible, or is too time consuming, and it would be better to heat the foam prepolymer „online“. For this we need a heat exchanger, which can be mounted on normal OCF gun, for preheating of the prepolymer mixture, prior to foaming. "
There is some interesting information in some of the comments which may be of use designing your concept. Well worth a look .
Hope this is of some help.
Kind Regards
Alan Baird
D. Daum about 13 years ago
How about using butane heating a coil unit
Meelis Klimov about 13 years ago
As the foam can contains flammable gases, there is a fire hazard in the working space. So, the butane burner safety can be an issue.
Kaspar Kiis about 13 years ago
Due to few request we have extended the deadline until the end of Sunday. There is still plenty of time to submit your design. Good luck!
teigan about 13 years ago
i love that so many of you have submitted designs that ignore the doomed to failure requirements given, and are heating the can instead. because your way could actually work.
Meelis Klimov about 13 years ago
If our goal was to heat the can, we would not have set up this challenge at all, because heating the can is not a challenge.
teigan about 13 years ago
i am all for challenges, but most of us here are engineers or engineering students. and after doing the math, based on amount of time the foam spends in the gun, and the heat transfer rate with ideal materials, we decide to exercise professional integrity and advise you to consider alternatives. maybe i will enter something, but i would also have to exercise professional courtesy and fully disclose that the foam heating would be negligible even if you made the gun tip out of silver or diamond.
Michele Gorra about 13 years ago
we are talking about a 20°C heating target... human breath... not a critical application, even for engineers :)
Jaan Puusaag about 13 years ago
We are talking about heating the can in a split second. The can that contains flammable gas and expolodes at 60 degrees celsius. The normal resistance of 15 bar can. An engineer would say this is impossible in a safe way. We need to heat foam, not a can!
teigan about 13 years ago
no ergosysmed. 0-20 degrees is the target which makes it even easier. what makes it difficult/impossible is doing so in a very short time without overheating. some people are lengthening that time with an additional barrel length, but not significantly. worry about the can exploding is ludicrous. the heat of the human hand would be sufficient to keep the contents between 0- 20 C. in fact you should make a new inverted gun design where the can is the handle and the mix tube is on the bottom. that would eliminate the need for electrical heaters.
Michele Gorra about 13 years ago
Even with gloves on?
Jaan Puusaag about 13 years ago
The temperature of the foam at application has to be at least 20. Not between 0-20. Please read the requierments carefully.
teigan about 13 years ago
we do read the requirements carefully. please word your requirements unambiguously. you're welcome.
Jaan Puusaag about 13 years ago
Go ahead and heat the can as much you like.
teigan about 13 years ago
ok. so are you implying there is no upper limit to the heating? because then you could superheat the gun tip and achieve the desired heat transfer in seconds. your stated requirements led me to believe too much heat was as bad as not enough heat.
Jaan Puusaag about 13 years ago
There was a link above to the technial datasheet. The ideal temperature of foam for application is 20 - 25. When it is less there will be less yield and when it exeeds 30C the viscosity drops an it would not stay in joint. Thats why it important to keep the aplication temp within these frames. I hope this explains.
QAPGAN™ about 13 years ago
I have uploaded my design but it does not seen on competition page.
Krimelte Foam Heater-tXs
magedelmohands about 13 years ago
i have uploaded my design too but it dosent seen on the compition page whats the problem?
magedelmohands about 13 years ago
foam heater
my design dosent appear
it is not fair
Kaspar Kiis about 13 years ago
We will make sure that all the missing entries are listed latest by the end of today. If you still can't see your model, please send me an e-mail to kaspar@grabcad.com
Kaspar Kiis about 13 years ago
Thank you to everybody participating in the challenge. We will start selecting the winners and will announce the results during one month but still asap.
Alan Baird about 13 years ago
Congratulations Mohomed, and to all the other placed winners
Mohomed Nusry about 13 years ago
Woah… I’m really excited with this win! :) :) :)
Thank you Alan, and congratulations to all other winners.
Vincenzo Ricci about 13 years ago
hey guys, the shirt has arrived, is fantastic! Thanks to GrabCad and congraturazioni at all! ^ ___ ^
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