Lime Silo Dosing System | Lime Slurry Preparation and Dosing Unit

Working Principle

Lime powder sits in a sealed silo and is fed by a screw conveyor or rotary valve into the slaker or slurry tank. Water is added and mixed, bringing the lime to a 5%–10% slurry. A mixer keeps running so the lime doesn't settle out. The metering pump then pulls the prepared slurry from the storage tank and doses it into the reaction tank at a set flow rate. Level controls and anti-clogging features keep the lime slurry flowing steadily.

Application Fields

1.Municipal wastewater: adjusting pH or acting as a phosphorus removal agent alongside flocculants to improve settling.
2.Industrial wastewater: neutralizing acidic wastewater and treating wastewater containing heavy metals.
3.Flue gas desulfurization: continuously dosing lime slurry in wet FGD systems to absorb sulfur dioxide.
4.Water supply treatment: softening water by removing temporary hardness.

FAQ

Q1: Why does a lime silo need anti-caking features?
A: Lime powder soaks up moisture and cakes easily, especially in humid weather or during the rainy season. Silos usually have vibrators, arch breakers, or fluidizing pads to keep lime from bridging or caking at the bottom and to keep it flowing smoothly to the feeder. A good seal also matters—it keeps rain and moisture out.

Q2: What concentration is lime slurry usually kept at?
A: Typically 5%–10%. Too high speeds up pipe wear and settling; too low means you're moving and dosing a lot more water, which raises energy use. The exact number depends on the process and the lime quality. The mixing tank and storage tank are set up separately, and the storage tank needs continuous low-speed mixing.

Q3: Why do lime slurry dosing lines clog?
A: Mainly from settling and crystallization. Avoid long horizontal runs, cut down on elbows, and install flush connections. Flush the lines during shutdown so leftover lime doesn't harden. When choosing a metering pump, go with pump heads and valves built to resist wear and crystal clogging.