Raw sugar manufacture

The precipitated mud is removed in a settling device known as a clarifier. The better known clarifiers in the market are Rapi Dorr 444, the Graver clarifier, and Prima sap, Bach clarifier. Poly-cell, and BMA clarifier. Basically, a clarifier consists of a vertical cylindrical vessel composed of a number of trays with conical bottoms stacked one over the other. The limed raw juice enters near the center of each tray and flows toward a circumference. A sweep arm in each tray turns quite slowly and sweeps the settled mud toward a central mud outlet. The clear juice from the top circumference overflows into a collection compartment. With more uniform juice takeoff, the potential stagnant pockets are eliminated. 

The clarification process divides the whole juice into two portions (1) the clarified juice and (2) the precipitated settlings, which are the 

The use of sulfur dioxide in addition to lime makes a better clarification. In this method (sulfitation process), lime is added as usual, but then sulfur dioxide from a sulfur burner is bubbled through the juice. The precipitate is settled as in the ordinary clarification process. The bleaching effect of sulfur makes a lighter-colored sugar. The extra cost of sulfitation, increased sealing in heaters and evaporators, and higher ash in raw sugars are reasons for the discontinuance of this process. 

There are other white sugar processes such as (1) treatment with vegetable carbons, (2) treatment with ion exchange resins, and (3) Talodura process. These processes are in fact supplemental clarification methods, adopted by some manufacturers with specific objectives. 

The usual single-effect evaporator, in its simple form, is a closed, vertical-body pressure vessel divided into two sections by a pressure-tight 

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Basic scheme of the raw sugar manufacturing process in a sugarcane factory... 

The process of raw sugar manufacture is essentially that of separating by chemical and mechanical means sucrose from the sugar cane. The process can be broadly divided into the following steps see Figure 17.1 for a flow diagram of the process ... 

Continuous vacuum pans have been successhiUy developed for raw sugar crystallization, and are widely appHed in South Africa, AustraHa, South America, and the United States. Continuous crystallizers, developed for beet sugar manufacture, are being adapted for use in cane sugar factories. 

Traditionally, raw sugar is produced at the cane mill and refined sugar is produced at a refinery, usually far removed from the source of the raw sugar, and close to areas of consumption. Figure 35.1 is a generalized flow diagram for the manufacture of raw cane sugar. In summary, the juice is extracted from the harvested cane stalks, the juice is purified (clarified), concentrated by vacuum evaporation, and crystallized. The several steps are described in the sections that follow. 

Fig. 35.1. Generalized flow diagram of steps in raw cane sugar manufacture. (Adapted from Clarke.59)...

Figure 6.2 Typical flow diagram for the manufacture of raw sugar from sugarcane.

Basic scheme of the white, refined sugar manufacturing process in a raw sugar refinery. Clarification can be phosphatation or carbonation, and decolorization can be with granular carbon, bone char, or ion-exchange resins. Filtration is not required if phosphatation clarification is utilized... 

Use Feed, food, raw material for various alcohols, acetone, citric acid, and yeast propagation. Sodium glutamate is made from Steffens molasses, a waste liquor from beet sugar manufacture. 

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