Extracting Sugar from Beets
By Lois Kerr

centrifugals
White sugar centrifugals are for recovering sugar
crystals from "boiled" syrup and moss.

The fundamentals of extracting sugar from beets has not changed in 100 years. What has changed is the technology enabling sugar beet factories to operate more efficiently, more safely, and to end up with a purer product.

The Sidney Holly Sugar factory has kept up with technology ever since it opened its doors in 1925. Over the 75 years of plant operation, the factory has continually improved the extraction process, and today, this factory uses some of the most modern technology and equipment available to produce top quality sugar. This sugar extraction process consists of taking raw juice through successive steps of diffusion, purification, filtration and evaporation, using up-to-date techniques and equipment. These processes result in the crystallization of sugar.

The entire sugar extraction process begins when trucks, hauling the beets from the various receiving stations, dump their loads of beets into a wet hopper at the factory. This hopper begins the process of removing dirt, clumps of mud and other external debris from the beets while it moves the beets along a conveyor towards the factory. As beets move towards the factory, the rocks, mud, and other debris which is washed off in the wet hopper get carried in the opposite direction, back outside the conveyor walls. This sludge is deposited outside, where loader operators haul it away.

The beets themselves proceed through two separate rock catchers. Any rock that reached one of the slicers would ruin the slicer knives, so Holly Sugar has two rock catchers designed to separate and remove rocks from the beets.

A beet pump moves the beets from the hopper into a washer, where beets receive another cleaning. Factory personnel ensure beets are as clean as possible before the beets enter the slicers, the next step on the journey through the factory.

The Sidney factory has four slicers. With all four slicers working, factory crews slice approximately 6,000 tons of beets on a daily basis. Sliced beets, called cossettes, look like skinny strings as they leave the slicers. These cossettes move by conveyor to the Cossette mixer. The Cossette mixer adds hot water to the sliced beets, continuously turning and mixing the water/beet blend. This water/beet mixture then moves from the Cossette mixer to the tower diffuser.

The tower diffuser begins the process of separating sugar from beets. The diffuser separates the raw juice, which contains the bulk of the sugar, from the solid matter, or beet pulp. Raw juice leaves the diffuser to undergo a series of purification and evaporation processes. The wet pulp leaves the diffuser and moves to pulp presses, which extract as much water as possible from the pulp. Equipment returns this liquid, since it contains sugar, to the diffuser for reclamation as juice.

The raw juice, which leaves the diffuser, enters the carbonation process. Holly burns lime rock to produce carbon dioxide gas (CO2) and milk of lime, both necessary for the carbonation process. Crews first add a small amount of milk of lime and underflow to the raw juice to begin the purification process and at the same time set the proper pH levels. Crews then blend the remaining milk of lime with the raw juice, then add the CO2 gas during the first carbonation. The carbonation filters remove the non-sugar particles in the raw juice. Raw juice goes through one additional carbonation for purification before moving into the vacuum filters.

Vacuum filters and the Enviro-filter continue the purification process, removing solids and foreign particles from the juice. The filtration process changes raw juice into a thin juice, ready for the evaporation process.

The remainder of the extraction process involves repeated evaporation of the thin juice. The purified juice thickens in the evaporation process, going through repeated filtration and evaporation machines. Eventually, crystals form in the thick juice by a heating process done in huge vacuum pans. When heated to a critical temperature, sugar reaches a saturation point, and "seeding the pan" begins.

Huge centrifuge machines spin at high speeds, separating the white sugar from the excess liquid, now recognizable as molasses. The centrifuge sprays the sugar crystals as it spins to remove all trace of molasses from the crystallized sugar. The damp sugar then moves through air drums for drying. Equipment continues to dry and condition sugar so it enters the storage silos at the correct temperature and consistency.

Warehouse crews store, package and ship the sugar to customers throughout the United States. Much of the factory sugar goes by bulk rail cars to large buyers such as Kelloggs and Hersheys. The Sidney factory also sells sugar in 4, 5, 10, 25, 50, and 100-pound bags, as well as a 2,500-pound flex tote size. The warehouse ships much of the pre-packaged sugar by semi trucks.

Computers monitor the entire extraction process, from slicing beets to storage in the silos. Computer operators check each step of the operation, from monitoring tank levels, checking equipment performance and monitoring temperatures, to catch any problem quickly. The entire process is gauged and automated, allowing for a pure, uniform product.

Factory personnel also rely on the quality control data they receive from the Technical Services division. Lab personnel from the technical services division, or factory lab, monitor the entire extraction process, 24 hours a day, and make approximately 450 analyses every day on the various stages of the extraction process, including testing water samples, pH levels, conducting purity tests and analyzing the final product. This provides a consistent, top quality sugar.

The Sidney Holly Sugar factory does not produce brown sugar or confectioner's sugar. These specialty sugars are made at a Holly plant in Wyoming.

In a good year, it takes approximately one ton of beets to produce 300 pounds of sugar. In an average year, that same ton of beets produces about 250 pounds of sugar.

The Sidney plant produced a record three million hundredweight of sugar in its 75th year.

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