The Sugar Engineers

Sugar Factory Definitions

The definitions below are taken from Cane Sugar Engineering by Dr P W Rein and are used with permission

Treatment of raw sugar crystals to remove the film of adhering molasses. This is achieved by mixing sugar with a concentrated syrup and then centrifuging the magma with or without water washing.
Affinated sugar
Sugar purified by affination.
Sticking together of two or more crystals during the centrifuging and drying operations.
Ash content
Solid residue determined gravimetrically after incineration in the presence of oxygen. In analysis of sugar products, sulfuric acid is added to the sample, and this residue as sulfated ash heated to 525 °C is taken to be a measure of the inorganic constituents. Sometimes determined indirectly by measurement of electrical conductivity of the product in solution (see Conductivity ash).
Fine fraction of bagasse obtained by screening or pneumatic separation, generally used as a filter aid in filtration.
Cane residue leaving mills after extraction of juice.
Boiling house
That part of the sugar mill in which the processes of production of sugar from raw juice are carried out. It is also referred to as the back-end or raw house.
Boiling point elevation
Difference between the temperature of a boiling sugar solution and the temperature of boiling pure water, both measured at the same pressure.
Measure of dissolved solids in sugar juice, liquor or syrup using a refractometer, otherwise referred to as refractometric dry solids. For solutions containing only sugar and water, Brix = % sugar by mass. Spindle Brix is determined using a hydrometer, but is now seldom used.
Brix-free water
Water forming part of the cellulosic structure of the cane, and hence not part of the juice expressed in milling. It cannot be separated from natural fiber by mechanical means but is driven off at elevated temperatures.
Tubular or plate heating element in a vacuum pan or evaporator vessel.
Process involving introduction of carbon dioxide gas into limed juice or syrup to remove color and nonsugar solids.
Carbonatation gas
Gas rich in carbon dioxide for use in carbonatation.
Centrifuge used to separate sugar from mother liquor.
Apparatus for the separation by sedimentation of suspended solids from a turbid sugar solution.
Clarified juice
Juice from clarifiers, also referred to as clear juice.
Attenuation index, determined by absorption of light under defined conditions. Generally measured using the ICUMSA method at 420 nm, and referred to as ICUMSA units or IU.
Conductivity ash
Estimate of ash content by measurement of the conductivity of the solution.
Two or more crystals grown together during pan boiling.
Cooling crystallization
Crystallization by cooling of the massecuite.
Crystal content
Proportion by mass of crystals in massecuite, often expressed as a percentage, and referred to total massecuite mass or to massecuite dry substance (Brix).
Nucleation and growth of crystals.
Crystallization scheme
Defines the number and arrangement of crystallization stages involved in producing sugar.
Cush cush
The stream of wet bagasse or bagacillo separated from raw juice by the juice screens.
Cut a pan
Discharge a portion of the massecuite from a pan, retaining a footing upon which to feed more syrup or molasses for crystallization.
Dissolved solids
All solute material which is in solution, including sucrose, monosaccharides, ash and other organic impurities.
Drop a pan
Discharge all of the massecuite from a pan. Also referred to as striking a pan.
Dry substance
A measure of total solids obtained from evaporating a solution or massecuite under vacuum to dryness. Also referred to as total solids by drying or dry solids.
Entrainment separator
Apparatus for removing juice, syrup or massecuite entrained in the vapor.
Evaporator effect
One of a system of evaporators operating in series as a multiple effect system (e.g., first effect, second effect). Condensates and vapors are labeled correspondingly (e.g., first condensate and vapor one
condensate and vapor from the first effect respectively).
Applied to a massecuite, it represents the g of sucrose present in crystalline form per 100g of sucrose.
Proportion of sugar extracted from cane in the extraction plant; equals mass of sugar in raw juice as a percentage of mass of sugar in cane.
Extraneous matter
All cane leaves and tops, mud, soil, roots, rocks, stones and tramp iron delivered with the cane.
False grain
Undesirable small crystals, formed spontaneously by secondary nucleation when the supersaturation during crystallization is too high.
The dry fibrous insoluble structure of the cane plant. Generally taken to mean all insoluble material in the cane delivered to a mill, and therefore includes soil or other extraneous insoluble matter in cane.
Filter cake
Material retained on the filter screens and discharged from the filters after filtering clarifier muds.
Liquid passed through the screens of the filters.
Polyelectrolyte in solution added to juice to assist clarification.
A charge of massecuite retained in or transferred to a pan as the start of a massecuite boiling.
The process of adding imbibition water to the extraction plant to increase extraction. Sometimes incorrectly referred to as maceration (steeping cane in juice). Water added is called imbibition water.
Invert sugar
Mixture of approximately equal parts of glucose and fructose (monosaccharides) resulting from the hydrolysis of sucrose (inversion). Liming
Process step in juice purification in which lime is introduced into the sugar juice in the form of milk of lime or lime saccharate solution.
Liquid sugar
Refined sugar products in liquid form (e.g. liquid sucrose, liquid invert).
A sugar syrup, a term generally used in sugar refining.
Mixture of crystals and liquid (water, clarified juice, syrup or molasses) produced by mingling.
Magma mixer
Mingler, where crystal sugar and liquid are mixed together.
The mixture of crystals and mother liquor resulting from the crystallization process. Massecuites are classified according to purity as A, B, or C massecuites.
Massecuite mixer
Apparatus from which massecuite is distributed to the centrifugals.
Equipment in which dissolving of sugar takes place.
Another term for dissolving of sugar crystals.
The mother liquor separated from the crystals by centrifuging. A, B or C molasses is derived from the corresponding massecuites. C molasses is also referred to as final molasses.
Mother liquor
Liquid phase in the massecuite during crystallization; refers to syrup or liquor in which the crystals are growing.
Dissolved solids contained in any process stream other than sucrose.
Common overall term for dissolved solids other than sugar contained in any process stream.
Generation and development of small crystals capable of growth.
Pan or vacuum pan
Vacuum evaporative crystallizer used in the sugar industry to crystallize sugar from liquor, syrup or molasses.
Clarification using phosphoric acid and lime, in which certain nonsugar components are removed by flotation.
Polarization (or pol)
The apparent sucrose content expressed as a mass percent measured by the optical rotation of polarized light passing through a sugar solution. This is accurate only for pure sucrose solutions.
Press water
Juice expressed from dewatering mills after a diffuser.
The true purity is the sucrose content as a percent of the dry substance or dissolved solids content. The solids consist of sugar plus nonsucrose components such as invert, ash, and colorants. Apparent purity is expressed as polarization divided by refractometer Brix, multiplied by 100.
Raw juice
Juice obtained from the cane extraction process. Also referred to as mixed juice (from mills) or draft juice (from diffusers).
Raw sugar
Brown sugar produced in a raw sugar mill generally destined for further processing to white sugar in a refinery.
Reducing sugars
Generally referred to and/or interpreted as invert sugar, determined by measuring reducing substance content by laboratory analysis.
Purification of sugar through chemical and physical methods, generally including some or all of clarification, filtration, decolorization and recrystallization.
Refractometric dry solids (RDS)
Measurement of total dissolved solids in a sugar liquor or syrup using a refractometer. For solutions containing only sugar and water, % RDS = Brix = % sugar by mass.
A syrup made from centrifuged low-grade sugar which is dissolved or remelted and returned to the high grade boilings.
General term for syrups or molasses produced on centrifuging a massecuite.
Safety factor
Number to indicate keeping quality of raw sugar, calculated from pol and moisture content (= moisture (g/100 g sugar) / (100 pol)).
A sugar solution at saturation will not dissolve any more crystals at the temperature of the solution.
(a) Introducing crystal fragments to induce nucleation, as a means of initiating the crystallization process; (b) introduction of fine crystals in the form of a slurry (similar to full seeding) to start crystallization. Sometimes referred to as graining.
Suspension of fine crystals in saturated solution of alcohol, or the initial grain resulting from seeding in a vacuum pan.
Solubility coefficient
Ratio of concentration of sucrose in impure saturated solution to the concentration in a pure sucrose solution saturated at the same temperature (with concentration expressed as sucrose/water ratio). Referred to as saturation coefficient in the beet sugar industry.
Massecuite as a completed boiling, all of which is discharged from the pan.
Pure chemical compound C12H22O11 known as white sugar, generally measured by polarization in pure solution or by GC or HPLC in impure solution. The chemical term is β-D-fructofuranosyl @alpha;-D-glucopyranoside.
Term for the disaccharide sucrose and products of the sugar industry, essentially composed of sucrose.
Introduction of sulfur dioxide into juice or liquor.
The degree to which the sucrose content in solution is greater than the sucrose content in a saturated solution.
Supersaturation coefficient
Calculated as the quotient formed by dividing the sugar/water ratio of the supersaturated solution by the sugar/water ratio of a saturated solution under the same conditions (temperature and purity or nonsucrose/water ratio). It shows whether the solution is unsaturated (<1), saturated (=1) or supersaturated (>1).
Supersaturation, critical
Supersaturation at which nucleation begins spontaneously.
Suspended solids
Insoluble solids in juice or other liquid, removable by mechanical means.
Sweet water
Wash water or water containing a small amount of sugar.
The concentrated juice from the evaporators.
Target purity
Equilibrium purity of final molasses, derived from a formula taking into account the effect of nonsucrose on its exhaustibility. Sometimes referred to as expected molasses purity.
Cane tops, leaves, dead stalks of cane and any other vegetable matter delivered with the cane.