So, what happens to the cossettes that have had the sugar removed from them in the extraction process? The exhausted cossettes, called wet
pulp, leaves the diffuser at approximately 95 percent moisture. It would be uneconomical to dry it at this moisture content. Therefore, the
pulp is mechanically squeezed in four specially designed pulp presses (two for each diffuser) to remove excess moisture. This excess, called
“pressed pulp water” is returned to the diffusers.
The pulp after the presses is called “pressed pulp”. Molasses is sometimes added to the pressed pulp before being conveyed to the dehydrators,
which reduce the moisture content of the final product, “dry beet pulp”, to 10-12 percent.
The amount of dried beet pulp produced by a factory varies with the amount of insoluble material originally present in the beet as processed,
called “marc”, and with the amount of molasses added. It generally runs between 4.5 and 5.5 percent on beet.
The dry beet pulp may be sold either as produced or as pellets. SMBSC has pellet mills which, when equipped with the proper dies, can make
several different diameter beet pulp pellets. Beet pulp pellets are the standard for the foreign markets of Europe and Japan. Export quality
pellets have a sucrose content maximum and, therefore, molasses addition is often eliminated when making pellets for export.
SMBSC’s pulp dryers/dehydrators are unique. Originally designed in Norway, they utilize steam to dry the pulp. They work by keeping a floating
bed of pulp in motion (using a huge internal fan) located below a set of screens. Then, we recapture the vapor produced while drying the pressed
pulp (while producing the dried pulp), and using it as a source of steam for the multiple effect evaporators concentrating the beet thin juice.
In this way there is no direct exhaust of dryer gasses and less pollution results from the process than with normal dehydrators.
« Prev - Molasses
Next - Lime Production »