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Comparison of VIM III with Ecovim II |
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The VIM III
The first Vacuum Ice Makers, which were installed for mine cooling, were called Eco-VIM (Ecological VIM) due to the fact that they where using a cooling tower for the supply of cooling water to the VIM condenser. The Eco-VIM units were equipped with a horizontal two stage compressors system and were capable of using cooling water at temperature of up to 22°C. This cooling water temperature could easily achieve at the climatic condition of South Africa.
Due to global warming IDE developed a new design for the VIM which receives the required cooling water from a conventional water chiller and by that increases the VIM's availability and actually gives the units the ability to produce ice at any ambient condition. In the new VIM design IDE had also implemented modification and improvements as result form the 15 years experience of operating the unit at Mponeng gold mine.
The main design improvements were the implementation of a vertical design unit - equipped with one stage compressor, the use of greased bearings and dry vacuum pumps. These modifications improves the units operation and maintenance and, as already mentioned, secure the unit availability through any ambient condition.
The VIM unit is designed to produce 3000 kWR, which allow the production of 40 ton/hr of transportable slush ice considering feed water supply at 4.5°C.
1.Lower number of components yields:
Lower investment cost
Lower operational costs
Simplified operation
Increased reliability and availability
2.Insusceptible to ambient conditions (Global Warming)
Supply of 6°C cooling water is insured by a conventional chiller, hence eliminating compressor surge due to high ambient temperatures
Single stage compression eliminates the need to synchronize and adjust the compressors’ RPM
3.Reduced droplet carry over due to vertical configuration – inherent simplifications:
Minimal compressor’s blade erosion
Reduced necessity for brine spray
4.Reduced droplet carry over due to vertical configuration – performance improvements:
Possible reduced salt consumption.
economical improvements
ecological improvement
Possible elimination of the Knitmesh droplet separator will improve performance COP and refrigeration capacity (To be verified by field tests)
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ECOVIM II |
VIM III |
Vapor compressors
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2 |
1 |
350 kW Motors
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2 |
1 |
| 350 kW frequency controllers |
2 |
1 |
| Compressor lubrication system |
Oil pump
(operating under vacuum) |
Grease
(Passive) |
| NCG Removal blower |
1 |
none |
| Condenser cooling water temperature |
Up to 22°C |
6°C |
| Condenser cooling water source |
Cooling tower |
Conventional chiller |
| COP (compressor only) |
4.3 |
9.5 |
| Configuration |
Horizontal |
Vertical |
Download brochure:  Differences between Ecovim II to VIM III
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