How to cool raw and amorphous sugar
Case study examines use of vertical plate heat exchanger technology
Author: Jean-Marc Reichling
Vertical plate heat exchangers have long proven to be successful in cooling crystalline sugar. For more than 20 years, Solex Thermal Science has successfully integrated the solids cooling technology in sugar plants around the world – including France, Germany, Portugal, Mexico, Poland, Russia and the United States.
Until 2015, the plants using this type of sugar cooler typically processed refined sugar – sugar beet plants, cane sugar plants, refineries and producers of starch or derivative sugar (maltose, sorbitol). More recently, sugar plants have approached Solex seeking a method to efficiently and reliably cool amorphous and raw sugar.
To evaluate the unique challenges associated with these types of sugars, Solex conducted a series of pilot tests under actual process conditions at the San Carlos plant in Colombia (raw sugar) and another plant in Brazil (amorphous sugar). Highlights and conclusions are below.
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Amorphous sugar
Test conditions
- Product type: Amorphous sugar with a moisture content of 0.2%.
- Cooling water: Water module used (at 2,300 L/h) with temperature controller.
- Dry air purge: Testing with and without air injection.
- Product flow rate: 400 to 800 kg/h.
Summary of results
Conclusion
The data and observations collected during the series of tests show that the use of a Solex heat exchanger is a suitable method for cooling amorphous sugar at 0.2% moisture content, offering promising cooling capabilities, convenient operating conditions and utility savings. It is crucial to inject some dehumidified air to avoid caking from occurring.
Raw sugar
Test conditions
- Product type: Sugar VVHP with a moisture content of 0.1%.
- Cooling water: Water module used (at 2300 L/h) with temperature controller.
- Dry air purge: Testing with and without air injection.
- Product flow rate: 200-400 kg/h.
Summary of results
Conclusion
The data and observations collected during the tests shows the use of a vertical plate heat exchanger technology is a suitable method for cooling raw sugar (type VVHP tested), offering promising cooling capabilities and convenient operating conditions.
The optimal plate spacing was determined during the test for this application. A vibrating discharge feeder provided target production feed rates and turn down. A dry air injection system was integrated as part of the proposed design for optimal use of the cooler without the need for frequent cleaning.
Raw sugar cooler at Ingenio San Carlos, Colombia.
Installation at Ingenio San Carlos, Colombia
Ingenio Mayagüez is one of the leading producers of sugar in the Valle del Cauca region of Colombia. As part of a recent modernization at the plant, the engineers were in search of the most cost-effective and efficient way to solve the problems associated with high sugar temperature and decided to implement the vertical plate indirect heat exchanger technology offered by Solex. The goal for the investment was to lower the final sugar temperature to the storage level (<35°C) to avoid caking during storage.
Process data for the sugar cooler at San Carlos:
- Product flow: 15 t/h
- Sugar crystal size: 0.9- 1.1 mm
- Moisture content: < 0.15%
- Product inlet temperature: 55°C
- Product outlet temperature: <35°C
- Cooling water temperature: 25°C
- Cooling water flow: 20 m³/h
- Dew point of injected air: 20°C
Due to the high relative humidity in this part of South America, the decision was made to inject a small amount of air from a blower into the equipment to help remove the moisture that migrates during the cooling process and ensures proper flow of sugar between the plates. This blower only demanded a fraction of the energy that would be necessary for a rotating drum or fluidized bed cooling system.
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Want to learn more about how Solex can solve your sugar cooling needs? Contact a Solex team member today.
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This entry was last updated on 2023-7-13