Complete sludge dewatering line
Maker: Hiller
Year: 2020 (never used)

Technical data decanter:
Throughput capacity decanter: up to 20 m³/h
Preparation capacity polymer unit: 1000 l/h from 0,1% to 0,5% solution
Capacity polyer preparation pump: 60 – 1200 l/h
Capacity sludge pump: 2 – 25 m³/h

Sludge parameter:
Medium: wastewater from paper production
DS-content: % 2 – 6 % solids
Feed temperature: + 0 bis 50 °C

Functional description
The dewatering plant is used for dewatering the wastewater of the paperproduction process.
The complete dewatering plant is controlled via a supplied and suitably equipped electrical switch cabinet. The operation is controlled automatically by a programmable logic controller (PLC). The particular centrifuge controller SEE-Control is installed next to the decanter in the upper container deck, for visualisation of the current parameter. The operation and monitoring of the entire system via a separate control panel is also installed
in the local control room on the plant.

The suspension (sludge) passes through the sludge feed pump through an inlet pipe into the rotating object chamber of the centrifuge. The solid content in the sludge is monitored by a solid measurement device. A additional sub dilution pump is also installed to thin the sludge in the moment of a high amount of solids, by adding process water. In the feed chamber, the suspension is accelerated in the direction of rotation and passes through openings in the likewise rotating drum. In the first section of the drum, the cylindrical part, the solid moves under the influence of centrifugal force to the drum wall. This process is called “clarify” and the section of the centrifuge is called “the clarification zone”. The centrifuged solid is transported by the scroll through the cone to the discharge of the bowl. The scroll rotates at a different speed than the drum. The speed difference between screw and bowl is called a differential speed. The liquid (centrate) is guided via an adjustable overflow edge (weir plates) of the drum. The distanve between two opposite overflow edges is called a weir diameter. The weir diameter is adjusted so that, depending on the task, pure centrate is produced by well dewatered solids.

To enable an optimum sludge dewatering, polymer is mixed with the polymer- pump (into the sludge. The polymer is set in its own self-contained preparation station, located in the lower deck container. Polymer product in liquid and in powder supply can be processed with this unit. For this process the polymer station provides automatically polymer by adding water.

The dewatered solid is discharged from the centrifuge via a spiral conveyor to a second conveyor outside. The conveyor outside is a swivel conveyor to load 2 dump containers.
The movement of the conveyor is either automatically controlled by switch positions, or manual by the operator by pushing buttons on the conveyor site.

When starting and stopping the centrifuge the liquid phase (“residual water”) is passed into the pump sump (supplied by client).

The resulting centrate is fed by gravity into an on-site drain. The operation of the plant requires (starting and stopping) the presence of monitoring staff.

The operation of the system requires the presence of supervision personnel.