Heating / Cooling System

I am working on a project which needs to heat a small cylindrical mold (1/2" diameter x 3/4" length with 2" heating tail).

I have tested the mold successfully on a soldering iron, as shown in the picture. But, I need to build a proper set-up which can heat the mold tail quickly for temperature more than 200 deg. Cent., for 15 seconds and after that cool down the mold immediately.

For cooling down, I am considering to use an aquarium pump to circulate water through a sleeve around the mold. But for heating, I need suggestions. Can anybody help me in this regard with some diagram/circuit?

Hi Friend

for such task you required peltier, like temperature rise and fall required by you, good choice is peltier it will cool the object with in 30 second and rise temperature with in 30 second

regards
Fragrance

Fragrance said:

Hi Friend

for such task you required peltier, like temperature rise and fall required by you, good choice is peltier it will cool the object with in 30 second and rise temperature with in 30 second

regards
Fragrance

Click to expand...

Hi Fragrance

Thanks for your response.

I don'thave any idea about the peltier. Would you please guideme further, how can i use it. And what could be its cost?

abuhafss said:

Fragrance said:

Hi Friend

for such task you required peltier, like temperature rise and fall required by you, good choice is peltier it will cool the object with in 30 second and rise temperature with in 30 second

regards
Fragrance

Click to expand...

Hi Fragrance

Thanks for your response.

I don'thave any idea about the peltier. Would you please guideme further, how can i use it. And what could be its cost?

Click to expand...

hi

simply go here and for driver circuit used google you will find lot of driver circuit

https://uk.farnell.com/jsp/search/b...arch_001&Ntt=peltier&Ntx=mode+matchallpartial

regards
Fragrance

Only special high temperature peltier elements can work up to 200°C. Practically, the temperature difference across
a peltier stage is limited to about 50K, so a complex multi-stage design would be needed to achieve 200°C by peltier
heater. It also needs a secondary heat exchanger, e.g. a heatsink.

If you combine a resistive heater with peltier cooling, you have to isolate the peltier from the heated zone, or it
would be heated up to the high temperature.

There's no more effective cooling method than liquid or vapor phase. The problem is, that it won't be available
in many cases. If water cooling is an option, then it's the perfect solution.

Mounting a resistive heater to the design is an easy part of the project, I think. A thin capillary heater wound around
the heating zone is the most elegant way. An industry standard heating/cooling controller can be connected.

FvM

I assume you have gone through my earlier posts in this thread.

I am looking for a cheap but reliable solution for by project. Could you please comment on my design proposed in the 1st post. Will it be practicable? OR do you suggest some modifications.

I can't suggest modifications without a design. What you sketched above can basically work, I think. But it has
to be caculated in terms of thermal capacities, thermal resistances, heating/cooling rates, power requirement
and coolant flow.

How accurate do you need the temperature to be? With a small object and high power/rapid heating you are likely to get overshoot unless you use at least the derivative term of a PID controller. You can buy PID controllers I think. An alternative is to simply add a derivative term into an analogue temperature controller. I did one many years ago which heated 40cc of water to 100C in 7 seconds. The control worked pretty well with just ON/OFF control plus a simple derivative. Rather bizarrely, it also had an aquarium pump in it, but an air one to displace water and pump in cold from a reservoir.

Are you planning to heat the water as well? If not, you will also need an air pump to clear it after cooling ready for the next cycle. An aquarium air pump could probably do that job.

Keith.

Hi,
Of course, I dont no what means for you in that project "cheap", but I know these Soldering Station producer, what heats in 2 second to tin melting temperature(you can set it in wide range) & the arent so expensive as clearly slower Metcal or Ersa ...
https://www.jbctools.com/tech-area
https://www.howardelectronics.com/jbc/revolution.html
These soldering irons are originally Japan products, but for us they are produced in Spain...
Only one question is in my opinion the adaptability of tips for your heating system...
I think these is "value" to ask the firm JBC
K.

P.S.:
Of course, you can heat with a flex PCB as resistive element too_they are really not cheap systems, or even with a winding heater wire system (older soldering irons), but they arent long life products :-(...

I have mentioned the size of the mold in my 1st post. The size is very small. For testing I have used simple iron mold, if required I can use Copper, Brass or Aluminum mold.

My objective is to insert a PVC tube in the mold. The heater should heat the mold to an ideal temperature to melt the tip of the PVC tube inside the mold (for a few seconds) and then the heater must switch off and the mold must be cooled down immediately by circulating water through the outer sleeve of the mold. All this process should be achieved with a single press of a triggering button.

The ideal temperature and time, has to be found out after testing various combination of temperature and time settings.

Added after 14 minutes:

keith1200rs said:

How accurate do you need the temperature to be? With a small object and high power/rapid heating you are likely to get overshoot unless you use at least the derivative term of a PID controller. You can buy PID controllers I think. An alternative is to simply add a derivative term into an analogue temperature controller. I did one many years ago which heated 40cc of water to 100C in 7 seconds. The control worked pretty well with just ON/OFF control plus a simple derivative. Rather bizarrely, it also had an aquarium pump in it, but an air one to displace water and pump in cold from a reservoir.

Are you planning to heat the water as well? If not, you will also need an air pump to clear it after cooling ready for the next cycle. An aquarium air pump could probably do that job.

Keith.

Click to expand...

Yes, I can use a PID controller.
The water or some other coolant is only to be used to cool down the mold.

Can anybody guide me if the circuit mentioned in the following website can do my job?

www.scienceprog.com/diy-pulse-soldering-iron

Hi,
These is the workings principial of the JBC Soldering Station what I did proposed on 11 Aug. ...
You need only good "distributed heating tips" (I think on i.e. 3 exemplares) in the mold-metall piece.
Greetings!
K.