Applications for a wide range of dewatering and thickening applications for fibrous and biological paper industry sludges
Proven and effective technology for sludge dewatering applications
The ANDRITZ sludge dewatering system portfolio covers all types of dewatering machines for all fibrous and biological paper industry sludges. Different types of sludges have different dewatering potential. ANDRITZ assists in finding the suitable solution for each and every application.
To evaluate the dewatering characteristics of these sludges, ANDRITZ can test the sludge at its pilot plant in Graz, Austria. As an alternative, a test run at your mill can be arranged by utilizing the ANDRITZ mobile test unit.
Gravity table GT: effective pre-dewatering of sludge with low solids in filtrate
The ANDRITZ gravity table is used as a first dewatering stage for sludge prior to subsequent pressing operations (e.g. pressure filters of sludge screw presses). Gravity is utilized to thicken the sludge from a feed consistency of 0.6–5% to a discharge consistency of 12–22%. The gentle treatment of the gravity table keeps the flocculent consumption low and results in a lower filtrate load compared to other pre-dewatering systems.
Benefits of ANDRITZ gravity table GT
- High thickening capacity
- Low energy consumption
- Minimum flocculent consumption
- Low solids load in filtrate
- Optional floating roll to increase discharge consistencies
Sludge screw press SCS: highest capacity, highest dryness
The ANDRITZ sludge screw press is designed for high throughput and for high dryness requirements. It utilizes a conical shaft and a decreasing pitch of flights on the screw to dewater sludge through a reinforced screen basket. Backpressure is automatically controlled at the discharge end to prevent blockage and achieve the highest dryness content even with changing sludge characteristics. The addition of a shaft dewatering zone at the end and optional steam heating can bring the sludge dryness up to 70%.
Benefits of ANDRITZ sludge screw press SCS
- Single-line solution with a throughput up to 180 t/d
- Shaft dewatering for higher final dryness
- Patented wear shoes to minimize downtime and maintenance costs
- Optional steam feeding boosts dryness to maximum
- Self-adjusting backpressure unit
- Fully closed system
- Minimal flocculent consumption due to fully automatic control (see: Polyscan)
Continuous pressure filter CPF: flexible dewatering of a wide range of sludges
The ANDRITZ continuous pressure filters (CPF) are double-wire presses with a modular design. The continuous pressure filter allows optimized dewatering of even hard-to-dewater sludges.
Depending on the sludge characteristics different machine concepts are applied: The CPF Rhino is well suited for a wide range of mixed sludges with low fiber and significant biological content. The CPF Hippo is used for very press-stable fibrous sludges. All ANDRITZ continuous pressure filters can be delivered with an integrated pre-dewatering table or, ideally, are combined with the ANDRITZ gravity table.
Benefits of ANDRITZ continuous pressure filter CPF
- Modular design adapts to varying conditions
- High dryness content of thickened sludge
- Low specific energy consumption
- High throughput with excellent filtrate quality
- Flexible press forces
- Easy accessibility for maintenance