Sugar Production

Massflow and Concentration measurement at a sugar plant

Sugar Production: Juice Cleaning

Milk of lime measurement

Thin juice naturally contains a lot of impurities and many non sugar substances which are eliminated in the juice cleaning process. The juice is cleaned by adding milk of lime to the thin juice. This has two effects: Coagulation of the fine dirt particles; binding of organic fruit acids through neutralization with milk of lime and thus conversion into salts.

Concentrate of milk of lime	Level switch at the lime kiln
To produce milk of lime, limestones (CaCO3) is burned with coke in the lime kiln. The burned lime is mixed with water and the result is called milk of lime. Measuring device on the pipeline for maintaining an optimum concentration of milk of lime.	The level switch located outside the lime kiln at high level position is used for automatically refilling the kiln with limestone.

Sugar Production: Evaporation

Concentration measurement

Radiometric density measuring systems are used to control and optimize the evaporation process. The best solution is installation of the measuring device on pipelines at the discharge of each evaporator.

Installation

Located at the discharge side of each evaporator, continuous on-line density measurement allows simple and precise control. By using the density gauge to increase or decrease the amount of material being withdrawn, the raw product is controlled within very narrow limits.

Sugar Production: Crystallization

Continuous Vacuum Pans

Radiometric density measuring systems are used to control the boiling process. The most important tasks are to determine the seeding time, monitor the crystallization process and determine the boiling point.

The proper selection of the seeding point is decisive for a successful crystallization process. The goal is to obtain crystals with a clear structure and even size. Too small crystals (fine grain crystal) cause:

Problems in later process clogging of sieves.
Have to be dissolves and crystallized again.
Higher energy consumption.

A certain quantity of sugar can be dissolved in water at constant temperature, at higher temperature, at higher temperature more, at lower less. The solution is saturated when reaching the maximum sugar concentration, that can be dissolved at a certain temperature. In the crystallizer (vacuum-pan) water is extracted from the juice through evaporator under vacuum.

Installation

The installation site should be offset by 180 degrees relative to the charge pipe for thick juice to ensure that the thick juice is well mixed with the masscuite. Measuring range: 75-95 Bx +/- 0.2 Bx. The shielding is usually installed:

Measuring point 1. In the cylindrical part of the vacuum pan below the heating chamber. Or, if there is no space:
Measuring point 2. In the cone-shaped part.

Instruments

The following combinations are usually used:

Detector: Sz 5 - D1 50/50 with lateral irradiation
Lead shielding with irradiation angle 45 degrees
Cs 137 radioactive source
Evaluation unit: Display ºBx. Output 4 - 20 mA. Measuring accuracy for super saturation: +/-0.01%
To make the installation as simple as possible the shielding has a bracket for the detector thus one must not weld the equipment to install it.

Charts of crystallization process

sugar charts.JPG (26701 bytes)

Density measurements on dissolved sugar

Radiometric density measuring systems are used for measurements on dissolved sugar to control the varying degrees of purity.

Massflow measurement on sugar

The radiometric weigher is a useful solution of measure on the sugar. Radiometric massflow measuring systems are used for measurement on sugar to control the massflow of production on a conveyor belt.