What is Flake ice?
Flake ice is a general purpose term used to describe types of ice which consist of irregular shaped pieces. These pieces can vary in size from very small, almost snow like particles up to fairly large pieces of ice 50mm across and in thickness from 1.5mm up to 10mm.
These different ice types, while superficially similar in apperance are often produced using very different processes and can have totally different physical properties, so it is important to identify which is the right type of flake ice for you.
Usually, when people say 'flake ice' they are talking about one of two main types. Ziegra refer to these two types as:
The confusion is not helped by the fact that ice machine manufacturers call their flake ice types by different and inconsistent names.
Luckily, regardless of what the manufacturer is calling their particular ice, there are certain key differences that will help you to identify what type you are actually looking at so you can be sure you are comparing apples with apples.
Chip Type Flake ice |
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Chip Type flake ice is made in a tall, narrow cylinder with an auger running through the centre. Water is introduced into the cylinder at the bottom, the auger then transports this water up through the cylinder, freezing it and forming it as it goes into 'chips' or 'flakes' of ice. These frozen pieces are then ejected from the top of the cylinder into the ice delivery pipe where it is then fed by gravity to the point of use or storage. As the ice is moved through the process by the auger, with no need to crack the ice from the freezing surface, the ice only needs to be taken down to -0.5°C which has a number of important benefits. This ice is not cold enough to re-freeze its own meltwater, so it has very good storage characteristics. The only thing that will happen during prolonged storage is that the ice will melt slowly, the remaining ice will always be loose, friable, in good condition ready for use. These good storage characteristics make this type of ice very popular, particularly for customers who are storing and using the ice in ambient conditions. Chip type flake ice is available in three different 'flake' sizes, micro, midi and macro (small, medium, large) to suit different applications. |
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chip ice evaporator |
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Scale Type Flake Ice |
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Scale type flake ice is made in a large, wide diameter cylinder which has an orbital reamer inside. Water is introduced into the cylinder at the top and flows by gravity down the inside walls, frezing as it goes and forming an ice scale on the inside wall 1.5 to 2.5mm thick. This ice is then 'cracked' from the wall by the orbital reamer as it passes and the ice falls through the bottom of the cylinder to the point of use or storage below. As the ice needs to be brittle enough to crack from the cylinder wall, we must sub-cool the ice to -7°C, which requires some thought as to storage. The first factor of this type of ice to consider is that in order to sub-cool the ice, we must add more electrical energy and unfortunately you do not get all this energy back as stored cooling energy, so this process is, in theory at least, is slightly less efficient. The second and far more important factor however is that this ice is cold enough to re-freeze its own meltwater. If it is allowed to melt, it will start to glue itself together into large unwieldy chunks, which defeats the object of choosing 'flake ice' in the first place. If the ice is to be stored for any length of time before use, then really it needs to be kept in refrigerated storage below zero. This refrigerated storage unfortunately only adds to the increase in electrical energy consumption for this type of installation. This disadvantage is sometimes an advantage though for customers who have plenty of refrigerated storage and want to utilise existing spare freezer space. |
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Scale ice evaporator |
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Summary As a general guide: if you are storing or using ice in fairly warm environments, Chip type flake ice would be the best to use. If you are storing or using the ice in sub-zero conditions, Scale type flake ice would be the best choice. If you are storing or using the ice in ambient conditions from 2°C to 5°C then either would perform well and in that case the ice should be chosen from personal preference or the particular demands of the application. Some suggestions to typical applications for each type are available on each individual ice page If you are still not sure which one is the best for you after reading the information on this site, then our applications engineers are always on hand for help and advice. |
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Ziegra Ice Machines (UK) Ltd Unit 2, Phoenix Court, Hammond Avenue, Stockport, Cheshire, SK4 1PQ Tel:0844 8808055 Fax: 0161 480 7927 Email: ice@ziegra.co.uk |