In need of a modification idea for the design of an ice making machine

[Scylla]

Hi all,
My Undergraduate thesis requires me to design an ice making machine by modifying existing machines. I will appreciate your ideas on how I should go about it.
Thanks in Advance!

 

[xxChrisxx]

Ok although this strictly isn't homework. It's pointless us just giving you the answer. Before we start I have a few comments to make, to stop you going wrong over the next year.

1. Pure design theses ususally get poorer marks than analysis or research theses.
You need to pick an espect of the design to analyse and then modify.

2. Broad titles and aims are bad. Limit the scope.
If you try to cover too much, you can't go deep enough. Which means you show only supperficial knowledge of the subject and hance get poor marks.

3. Research the living hell out of how something works and research methods before you start the project.
You need to know your subject basically.Before you do anything else, you are best getting the above sorted. What exactly is the aim of the project? What areas could you look at? Look for papers in these areas?

From an engineering point of view. (So I am talking about the phenomenon not the device)

How do you make ice?
Why do they work?
What system implement this?

 

[Scylla]

Hello Chris,
Thank you for your reply. Maybe my question was to broad so I will try my best and narrow it down as much as possible but first off I think let me lay the foundation of where I am coming from.
I school in a third world university and things are not as good as in the UK, or the US or in world standard universities. Over here the supervisor gives you a project topic and it is left for you to work your *** out, access to papers and journals are difficult and so on and so forth, the list goes on but I hope you get the general idea. Now this is not an excuse as I have done my homework at least to the best of my ability for now, and maybe I ought to modify the topic to include fabrication because I am fabricating it but I did not want to limit answers that was why I left it at design level.

This aim is to make available an compact machine that can produce ice at the shortest possible time in a tropical enviroment.

The principle I intend to employ is a simple vapor compression system and using brine as a secondary refrigerant. The high temperature and high- pressure refrigerant (primary refrigerant) leaving the compressor is condensed and collected in a receiver, it passes through an expansion device and through evaporator coils surrounding the brine tank. This low pressure refrigerant will absorb heat from the brine solution and when it gets to the vapour state it is once again fed into the compressor forming a simple vapour compression cycle. Water in modified ice cans is placed in tanks surrounded with cooled brine, the brine which acts as a secondary refrigerant will be kept at a constant temperature of -10oC by action of a thermostat connected to the compressor and it will also be moved in constant motion by an agitator to improve heat transfer between water in the ice cans and the brine solution. The brine then absorbs heat from the water in the cans.

This is the point I am at now, what else do you think I am lacking?

Thanks a lot for your help.
Cheers.

 

[xxChrisxx]

Usually in University projects, you get few marks for the design and for actually making it. You get the marks for explaining why you made the design decisions.

So what you have done is good, looking at the thermodynamic cycle can help you to make infomed design decisions. Such as selecting the correct compressor, or heat exchanges sizes. As you put in bold the key is that it's a trpical, so therefore likely to be a humid enviroment. You may want to look into the issues that this will cause to a refrigiraion cycle. Looking at the external factors of temperature and vapour saturation.

This will also have a practical effect on any compressor you will use. Generally trying to compress saturated and unsaturated vapour is bad. The humidity may have an effect on that. I know any fluid droplets destroys turbines quickly (whish isn't an issue as you won't be using one, but I don't know if it would do the same to a compressor.

So far what you have done looks good. I can't really remember enough about refrigiration to comment technically. I'd have to read up on it, but don't have the time to at the moment. Someone around here will be able to give good technical advice.One big thing to remember, every single step you take, everythig you do. You have to be able to explain why you did it, not just what you did.

But so far so good.

 

[Scylla]

Still waiting for replies, a thought comes to mind though. I could install an ice level sensing system in it, does anyone have an idea how I should go about that?