An automated process combining plate filter press efficiency and centrifugal productivity. Up to 30% reduction in sludge bulk compared to conventional dewatering is possible with Dehydris Twist

1. Dehydris™
Twist
BOOSTED SLUDGE DEWATERING BIOSOLIDS
USING PISTON PRESS TECHNOLOGY
BOOST YOUR PRODUCTIVITY
P-PPT-B-008-EN-1107
IN SLUDGE DEWATERING

2. BIOSOLIDS
BIOSOLIDES
CONTENTS
Dehydris™
Twist • Dehydris™ Twist on the dryness scale
• Dehydris™ Twist Workshop
• Uses and post treatments
• A Partnership with BUCHER UNIPEKTIN
• Operating Principle
• Dehydris™ Twist Advantages
• Case Study: Châteaubourg (35), FRANCE
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3. Dehydris Twist ON THE DRYNESS
BIOSOLIDS
BIOSOLIDES
SCALE
Dehydris™
Twist 60 – 90 %
20 – 45 %
4–6%
0,4 %
Dryness
Process Thickening Dehydration Drying
Sludge Volume /
Extracted Water
Volume
Range Name Drainis™ Dehydris™ Evaporis™
Dehydris™ Osmo
Evaporis™ LT
Process Name Drainis™ Turbo Dehydris™ Lime
Evaporis™ LE
Dehydris™ Twist
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4. BIOSOLIDS
BIOSOLIDES
Dehydris Twist WORKSHOP
Dehydris™
Twist
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5. USES AND POST TREATMENTS
Dehydris Twist
Uses Uses
Post treatments
Incineration
Landfill • Dryness close to self-sustaining Agricultural use
level with no addition of lime
• Reduction of cake volume • No recycling (low temperature • Reduction of cake volume
• Use of settled soil (drinking drying, belt-drying) • Improvement with lime-treated
water) as covering soil settled earth
in landfills
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6. IN PARTNERSHIP WITH BUCHER:
THE PISTON PRESS
The piston press is a patented technology that
was initially designed for solid-liquid separation
in the agro-food sector, with more than 2,000
references.
Its application to wastewater treatment sludge
(drinking water and wastewater) makes it
possible to reach a particularly high-level of
dryness.
In order to more widely deploy this sludge
Closed cylinder piston unit
dehydration innovation, Degrémont and Bucher
Unipektin signed an exclusive partnership
contract in June 2011.
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7. OPERATING PRINCIPLE (1/2)
The principle is based on the application of high pressure on the sludge in a
cylindrical chamber with a hydraulic piston.
The uptake of the interstitial water is through flexible cylindrical drains
(sleeve of filtering cloth on a polyurethane rod) mounted in a cluster between
the bottom of the chamber (cylinder) and the piston.
Filtration
Membrane
Filter Cake
Filtrate
Flexible drain
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8. OPERATING PRINCIPLE (2/2)
Duration of a cycle: 2h to 3h depending on the type of sludge
1 SUPPLY PHASE 2 PRESSING PHASE 3 DISCHARGE PHASE
The cylinder is closed and the The piston continues its back-and- The envelope of the cylinder slides
cylinder/piston unit is put in forth motion while the cylinder/ in the axis of the machine,
rotation. piston unit is still in rotation: the uncovering a part of the pressing
The piston moves back and forth; breaking of the sludge clods chamber. The cylinder/ piston
the sludge feeding occurs with during the return stroke renews rotation continues while the piston
each return stroke of the piston the contacts between the sludge moves forward. The dehydrated
until the nominal volume of dry and the filtering medium, which sludge cake fall by gravity aided
matter is reached. facilitates the release of the by the drains which tip over during
The sludge filling is automated interstitial water trapped during the rotation. The emptying occurs
with concentration and flow the pressing. over the course of a few minutes
measurements. The phase stops on a value of the with no outside intervention.
stroke of the piston calculated by
the automatic system with respect
to the input dryness and the
volume of water extracted.
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9. BIOSOLIDS
BIOSOLIDES
Dehydris Twist ADVANTAGES
Dehydris™
Twist
• 100% automatic operation with no staff present,
including emptying
• High productivity: 24 hours/day, 7 days/week
operation possible with a base of 8,000 hours/year
taking maintenance requirements into account
• High dryness with no addition of lime (wastewater
sludge close to autothermicity before incineration)
• Compactness greater than that of a press filter
• System easy to operate:
- Ergonomic process
- Covered piston press
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10. CASE STUDY (1/3):
CHATEAUBOURG, FRANCE
CONTEXT:
• 600 m3/h drinking water plant
• Client: Syndicat Mixte des Eaux de
la Valière (SYMEVAL)
• Commissioning of the plant: End of
2012
• Type of water: surface water
Stor
SITUATION: age
• As the raw water had a high level of
organic matter and pesticides, the
client sought an appropriate
treatment adapted for the final use
of the sludge. The soil-spreading
approach that was initially planned
involved large sludge treatment and
storage facilities. Degrémont
therefore proposed a multi-use
solution.
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11. CASE STUDY (2/3):
CHATEAUBOURG, FRANCE
DESIGN:
• WATER LINE:
- Remineralization, clarification, carbon contact reactor, filtration on sand, ultrafiltration
• SLUDGE LINE:
- Storage of sludge in a tank before pumping
- Thickening and storage in a static thickener,
- Pumping of sludge and then dewatering by Dehydris™ Twist,
- Storage in hoppers.
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12. CASE STUDY (3/3):
CHATEAUBOURG, FRANCE
Storage
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