sizing of an external serpent of a tank

[Teo-77]

Good morning to all,
Sometimes I happen to draw tanks with heating snake. the sizing data is given directly by the customer. I therefore had a curiosity to undergo. I wanted to know at a purely didactic level, how to dimension an external serpent of a tank.
- we hypothesize a vertical reservoir of 2000 litres. in 4 mm thick 304 aisi
- I put it back with water at 20°c and I want to take it to 50°c
- the heating I do it with a half pipe snake always in aisi 304, welded directly on the outer wall of the virola. we imagine that in its interior we spend hot water or steam

I therefore wanted to know how to calculate the snake, diameter of the half tube, thickness and number of coils to be applied.

I'll get you a picture I found on the internet.

Thank you very much in advance

 

[TETRASTORE]

good morning teo-77, the tanks you refer to are commonly called reactors with heating coil and are used in the chemical and pharmaceutical industry to activate processes that need a controlled temperature.
those in your image also have a reducer that through a system of blades keeps the internal product in motion in order to ensure as much as possible thermal uniformity, generally heating occurs by steam overheated.

the calculation is not as simple as you have assumed it because it has to take into account many more variables such as the thickness of the tank, the condensation of the steam, etc., however since your curiosity is at the didactic level, you can be useful to know also the various types of reactors that are used by the industry by viewing this document:3 general plantations (from page 3.1 - materials and types of reactors)If you want to have an idea of the calculations that are made to size these devices, I recommend you consult this doctoral thesis where in chapter 2 you will find the verification calculations of a reactor similar to yours con serpentina.energy characterization and optimization of plants for the pharmaceutical industryI believe that for you it may be a thesis of your interest because it also examines the processes of a company both in terms of production and energy saving and shows you where and how these reactors are applied for which you are only involved (for now) in the design.

 

[Teo-77]

Good morning, thank you very much for your kind answer. as soon as possible I will take a look at everything. I imagined that the thing was very complicated because in the occasional works where I happened to draw such tanks, the project data, always arrive and only directly from the customer . thanks again and good work.

 

[Cadinpiedi]

good morning, an example of calculation of the thicknesses of the semi-tube and the fasciame according to the old norms vsr, now a little decoction, but indicative of the methodology.

 

[mm1978]

good morning, an example of calculation of the thicknesses of the semi-tube and the fasciame according to the old norms vsr, now a little decoction, but indicative of the methodology.

good morning cadimpiedi and thanks for the example provided. do you have a spreadsheet to achieve this dimensioning? would be interesting.

 

[Cadinpiedi]

good morning mm 1978, sorry, but the press does not come from a common excel sheet but was generated by my program written with the relational database filemaker pro that contained almost all the rules of the norm vsr 95. However for several reasons I abandoned the development in far 2006, several releases orsono of the same v5 filemaker against v19, is therefore no longer operationally employable.

 

[mm1978]

Thank you very much.

 

[Teo-77]

"cad standing" thanks for the contribution