Lime milk production

During sugar production, raw juice is extracted from sugar beet or sugar cane, which contains various organic and inorganic components that can interfere with the subsequent production process. These non-sugar substances must be removed from the raw juice and for this, lime milk is used to precipitate these impurities. Depending on the sugar factory’s requirements, a suitable portion of the burnt lime scale from the lime kiln is fed into the rotary drum where the production of lime milk, takes place. Required parameters for clarified milk: density 20 ÷ 24 Be (Baume), temperature up to 80°C.

Separation plant

The lime preparation system is a unit of equipment, i.e.: lime slaking drum, grit separator and oval agitator for storage of dirty lime milk and a set of pumps feeding the lime milk to a battery of hydrocyclones, which are the final stage of its purification. The cleaned lime milk is directed to the clean lime milk oval agitator where it is intensively mixed. Slaking drum is a cylindrical tank with a horizontal rotation axis. Lime is fed through the hopper. The slaking fluid enters the drum via the inlet manifold. Inside the drum there are blades responsible for movement of the lime towards the outlet. The fines are discharged with the milk continuously through:

  • perforated sheet sieve (holes Ø15 mm),
  • slotted sieve (slots 3 – 5 mm),
  • an ejector for unburned lime with actuator and hydraulic unit,
  • grit separator trough, which connects to the lower part of the outlet housing (separates grit particles less than 3 mm).

The lime milk sludge is moved by scrapers towards the grit separator. To facilitate the segregation processes, water is fed into the grit separator with a sprayer. The washings are returned to the lime process. The purified lime milk flows into the oval mixer of the purified milk (the mixers are driven by geared motors). From the oval mixer, the milk is pumped for further processing to the de-saturating station.

The vapours from the slaking drum are removed via a gravity chimney. The screens are flushed with water, fed through a water system.

ŚFUP is the manufacturer of a complete installation for the production of lime milk in sugar factories.