The shell ice maker is one of the products manufactured by Berg which finds extensive application in the commercial fishing, food processing, produce, meat and poultry industries. These industrial ice machines are available in modules from 5 to 15 tons of cracked ice per day. Based on an old and proven principal of making ice on a tubular evaporator surface and harvesting it by gravity, the Berg Shell Ice Maker has become the industrial ice maker of choice in many areas and ice making plants.
Industrial Ice Making Process
The Freeze Cycle
Water is automatically introduced into the oversized sump, via the water make-up valve. The water is then pumped through the flow control valve to the distribution headers from where it is sprayed onto double-walled stainless steel evaporator tubes. As the water cascades down the inner and outer surfaces of the evaporator tubes it gets chilled down to its freeze temperature. The free water that does not freeze onto the tubes falls through a perforated trough and back to the sump. The chilled water is then pumped back to the water distribution header to cascade down the tubes again.
The Harvest Cycle
After the ice has formed to the desired thickness (as selected by the operator/user), hot compressor discharge gas is redirected into the tubes using solenoid valves; displacing the low temperature liquid refrigerant. As the evaporator tubes warm up a thin film of water is formed between the ice and the evaporator tube wall allowing the ice to fall freely into a trough below. Any free water produced in the harvest cycle falls through the perforated trough and is returned to the sump preventing “wet” ice from being discharged from the machine. The discharge auger in the trough reduces the ice shells into finely divided, irregular shaped fragments and also delivers the ice shells from the machine to the storage room below or for immediate use. The free water falls through the perforated deck and back into the sump. The cycle then automatically repeats itself.
Refrigerant condensing is achieved using either an air cooled, water cooled or evaporative cooled condenser. Remote air cooled condensers should be installed on a higher level than the machine whereas water cooled condensers are factory located on the lower front of the machine and pre-piped as a complete package. Where desirable, water cooled condensers can be cooled with sea water on shipboard and shore based operations. Evaporative cooling would be considered if the air ambient temperature was too high for efficient and economical use of either air or water cooled condensers.
Product Freezing – Blood Plasma and Juice Units
Sanitary requirements for these applications are paramount. Equipment must be stripped down and cleaned after each day’s production run. The construction of these 5-15-tons-per-day remote air-cooled ice making machines require major design modifications from our standard ice machines. All metal surfaces coming into direct food/plasma contact are constructed of stainless steel and all surfaces are given a glass bead finish.