Electrical Components for Water Heating Experiment

[Ciaci]

Dear all,

This post is connected to a previous one, but since the questions are different and independent, I preferred to separate them into two posts. I need to replicate a very simple experiment, but I have some doubts about the necessary electrical components to execute it. Specifically, I need to heat water to reach the desired temperature at a specific °C/min rate.

I was considering purchasing this component:
https://www.tcdirect.co.uk/product-2-100-10/1/16-DIN-High-Performance-PID-Temperature-and-Process-Controller-with-up-to-4-Set-Points-and-Timer-Function
and a PT100 .

However, I still have a few questions:

1. Obviously, I need to purchase an electric heater capable of bringing the water from 0°C to the desired temperature, and sizing this is not a problem for me. However, I am unsure which type of immersion heater would be suitable for my purpose. What characteristics should it have?
2. Will I be able to directly connect the heater to that PID controller, or will I need an additional component?
3. Do you know where I could purchase an immersion heater like the one in the attached image?
4. If I want to generate a data plot on my computer, will I need to purchase an additional component? If so, which one?

Looking forward to your advice, and thank you in advance!

Best regards,

 

[danw2]

>Will I be able to directly connect the heater to that PID controller, or will I need an additional component?

Depends on the "sizing" of the electric heater. The output has to be able to carry the current load of the heater. There are no specs for that controller, so the rating of the output relay or SSR (solid state relay) is an unknown. I suspect you'll probably need an interposing relay or SSR.

>If I want to generate a data plot on my computer, will I need to purchase an additional component? If so, which one?

Consider buying a controller with Modbus RTU (uses the RS-485 bus). A USB/RS-485 converter (FTDI chipset) will let a Modbus Master Window app on your PC talk to the controller and get the temperature values and log the values to a file as .csv values, which a spreadsheet can produce as a Y-t graph. Make sure that the controller talks Modbus RTU because the spec "RS-485" is a hardware spec and it could mean that the controller talks a proprietary protocol for which you have to write the driver to talk to the controller, which is a 2nd project in and of itself.

A Pt100 is an RTD, not a thermocouple. Two very different temperature sensors.

 

[Ciaci]

Thank you danw2. I am concerned about the heater, I cannot find any of that shape online. By "sizing", I mean "determinate the power required to let the liquid to reach a specific temperature", but I am not able to design it in detail. If I know the power of the resistance can I choose the SSR? (for example between these https://cascade.net/en/rkc-thyristor-units-solid-state-relays/=
Once I have the SSR, does the resistance consist simply in a bended pipe? Do you know company where I can order it?

 

[danw2]

The temperature sensor manufacturers have reps or distributors and have catalogs of 300 pages. And somewhere in the catalog most of them will offer an RTD with a 90 Deg bend. I took the graphic from a Pyromation catalog. Other vendors have similar stuff. Availability is largely geography dependent. I'm in the US. You're in ?.

In the US most companies that sell PID controllers (stocking distributors, not on-line only) sell temp sensors and SSRs. I assume that happens elsewhere.

Otherwise you might want to find an integrator to help you design and get it together. Configuring a PID controller without understanding conventional 'terminology' can be a hair puller (I'm retired and no longer do projects).

 

[IRstuff]

The immersion heaters like immersion heater on Amazon have the heater element inside the stainless tube. It would be crazy and dangerous to have a 120V-connected heater element directly immersed in water.

Frankly, you seem to be hung up on a specific implementation that doesn't have to be that way. Seems to me that heater I linked could be inserted into a hole in the side of a container which would then be sealed back up and no 90 deg bend would be needed.

 

[Ciaci]

The immersion heaters like immersion heater on Amazon have the heater element inside the stainless tube. It would be crazy and dangerous to have a 120V-connected heater element directly immersed in water.

Frankly, you seem to be hung up on a specific implementation that doesn't have to be that way. Seems to me that heater I linked could be inserted into a hole in the side of a container which would then be sealed back up and no 90 deg bend would be needed.

Yes, indeed, it doesn't necessarily have to be that way, but making a hole in a €400 glass container is certainly not a simple solution. The fact that it’s made of glass is important for the experiment to be able to see what’s happening inside.

 

[MintJulep]

That little controller looks like it would do the job, but I'd want the manual to understand how it drives the SSR in PID mode.

Or, you could buy a heater with a controller already included. https://www.mrclab.com/digital-immersion-heaters-up-to-100300c

 

[Compositepro]

Omega Engineering, Wattlow, and Chromalox are all major suppliers of heating systems and components. They have lengthy online catalogs with the educational material that you are looking for.

There are also numerous suppliers of laboratory circulator baths that can maintain bath temperature to within 0.01 degrees. These cost several thousand dollars, brand new, but you can find them on eBay or auction sites for a few hundred.

Chromalox Parts Catalog - Big Chief Inc.

Chromalox Parts Catalog Components

www.gobigchief.com