From Sugar Cane to Sugar Crystals

THERE ARE SIX BASIC PROCESSES INVOLVED IN SUGAR MANUFACTURING:

1. Preparation     2. Extraction     3. Clarification     4. Evaporation     5.Crystallization     6. Separation

CLARIFICATION OF CANE JUICE

Color of Squeezed Cane Juice (cloudy and highly acidic)

Color of Squeezed Cane Juice (cloudy and highly acidic)

Visitors at the sugar factory are generally surprised to see the color of cane juice after it has been squeezed from the cane: it is cloudy and highly acidic. This is the raw material that must be converted into sugar crystals in the Boiling House. But firstly this impure juice must be treated. The aim of this process is to produce a clear juice by removing the maximum amount of impurities (both dissolved and suspended) and to raise the pH enough to minimize inversion losses and prevent color formation during subsequent processing. Inversion is a common term in sugar manufacturing, which means color of squeezed cane juice (cloudy and highly acidic) that the sugar in the cane is being fermented by bacteria.

Pressurized Juice Heaters which raise temperature of cane juice to 280 degrees Fahrenheit

Pressurized Juice Heaters which raise temperature of cane juice to 280 degrees Fahrenheit

There are two important steps in clarifying cane juice; the first is to raise its temperature to 218 degrees Fahrenheit by passing it through pressurized juice heaters where steam or vapor is used as the heating medium to increase the juice temperature.

The second phase is to add white lime (calcium oxide) in solution to the hot juice to attain a pH of 7.5 -7.8. This hot, pressurized juice is then exposed to atmospheric pressure in an open vessel called a flash tank where it “flashes”, releasing all air bubbles adhering to the bagacillo (fine fibre from sugar cane) that comes with the juice. This vessel also assures a more uniform temperature in the clarifier.

Open Vessel called a Flash Tank which releases Trapped Air Bubbles

Open Vessel called a Flash Tank which releases Trapped Air Bubbles

As the juice enters this clarifier, it is treated with a flocculant (a substance that promotes the clumping of particles) which pulls the mud and bagacillo particles together to form large loosely clumped masses that settle at the bottom of the clarifier and the clear juice to overflow from the top. The clear juice is sent to an open vessel for processing, while the settled mud is sent to large filters to remove as much more sugar from it before being disposed of as filter press.

The next stage of the process is to begin the concentration of the clear juice through evaporation, which is the topic of our next segment.

You can find our Previous Articles in Previous Volumes: Preparation in Issue #1, Extraction in Issue #2 and Clarification in Issue #3

Meet Tower Hill Mill Employees at the Boiling House

                 Malco Cabrera                                   Amin Garcia

                 Malco Cabrera                                   Amin Garcia

Meet two of our Process Utility Assistants who assist as required to ensure the smooth operation of the Boiling House, Juice Heaters, Evaporators, Juice/Syrup Clarification and Mud Filtration section of the factory plant. They are also responsible for making up the Cooling Tower with zero hardness water as required and of regenerating the water Softener.


Posted on April 23, 2015 .