Liming of sewage sludge from a big bag emptying

Processed powder: Lime

Sludge liming

Manufacturer of dairy products.

The project consists of adding lime at the outlet of the filter press for the treatment of water from the manufacturing processes with a flow rate of 15 to 35 kg/h.

Big bag emptying unit:

Palamatic Process suggests the installation of a big bag emptying station EasyFlow EF0 with a low structure. This equipment is designed for the manual opening of all types of big bags, limiting dust emissions as much as possible and facilitating the flow of the powder.

The big bag is placed on this emptying structure using a handling cross. The big bag is positioned by the operator above the emptying structure using a forklift truck.

Once the big bag is in position, the operator lowers the handling cross with the trolley. The emptying structure is provided with a spike to burst the bottom of the big bag.  The lime can then flow into the hopper which allows the storage of a buffer volume.

Once the emptying is complete, the big bag is removed using the forklift truck and the handling cross.

The storage hopper is provided with a flat-bottomed anti-bridging device that facilitates the downflow of powders and the feeding of the dosing screw with lime. Its function is to ensure a mechanical mixing of the lime to avoid the powder to clump during the storage phases.

Dosing screw:

At the outlet of the hopper, the lime then flows into the tubular conveying screw which takes the material from the big bag discharge station to the lime distribution point, in this case an industrial mixer. This industrial mixer is fed by a second screw.

The continuous mixer consists of a tank containing two parallel rotors equipped with blades that cross each other during operation, thus covering the entire trough surface. The double parallel shaft mixer with secant pallets is used in applications where there is a need to mix two or more products but also to convey them during mixing. This industrial mixer allows the sludge to be treated with quicklime or slaked lime, which is then discharged from the filter press.

In order to minimize dust emissions, the unit is connected to an independent dust collector unit to ensure a clean and dust-free installation.

An M238 PLC completes the installation.