Andritz

Drying of Municipal Sludge

FOCUS: Belt Drying

Thermal systems

Paddle Dryer

Fluid Bed Dryer

Belt Dryer

Drum Dryer

Andritz Sludge Drying Systems

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Content

Introduction / Presentation Andritz Separation

Andritz Drying Technologies for Municipal Sludge

Focus on Andritz Belt Drying Systems

Worldwide References

LVIV, Sludge Conference; 11 2015; ANDRITZ Separation

3 Torrefaction of Biomass; CIBC; Price George; June 2012

The ANDRITZ Group

Overview

Company

ANDRITZ AG, Graz, Austria (Group Headquarters)

More than 180 production and service sites worldwide

Employees: approximately 24,800 worldwide (2014)

Key figures 2014

Order intake: 6,100 MEUR

Sales: 5,860 MEUR

Products and services

Plants and services for hydropower stations, the pulp and paper industry, solid-

liquid separation in the municipal and industrial sectors, the steel industry, and

the production of animal feed and biomass pellets

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ANDRITZ SEPARATION

ANDRITZ SEPARATION is a leading global supplier for state-of-the-art separation technologies,

offering a wide range of high quality equipment, systems and services for specific industries.

With more than 150 years of experience in the separation business, we serve our customers

every year with:

Products

Thickeners

Flocculant Plants

Drum and Belt Dryers,

Paddle Dryers

Fluid Bed Dryers

Filter Presses

Disc Filter

Drum Filter

Filter Centrifuges

Decanters

Separators

ThickenersCentrifuges and Separators

Filters and Filter Presses Thermal Systems

Screens, Drains, Screw and Belt Presses

Belt Filters, Belt Presses

Screens

Screw Presses

Conveying Systems

Belt Conveyors

Chain Conveyors

Screw Conveyors

ANDRITZ SEPARATION

We have offices in 24 countries serving your local requirements.

5 ANDRITZ SEPARATION | August 2014

Global presence

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Sludge Drying

Dewatered Sludge Dried Granules

• 18 - 35% DS

• Sticky

• Caloric heating value

< 1 MJ/kg

• biologically active

( digestion processes )

• > 90% DS

• free flowing

• Caloric heating value

- 8 - 11 MJ/kg (digested)

- > 12 MJ/kg ( non-digested )

• pathogen free

• biologically stable

by

from Waste to Product

Transfer of the dewatered sludge


Why Drying??


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4 Different Technologies

Fluid Bed Dryer ( FDS )

Drum Dryer ( DDS )

Belt Dryer ( BDS )

Gouda Paddle Dryer ( GPD )

Contact dryer Convective dryer


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1. Drying in a triple pass drum containing

three concentric cylinders revolving

around a joint axis.

2. The pre-granulated (backmixed) sludge is

fed into the inner cylinder of the drum

and is conveyed pneumatically by the

stream of hot gases ensuring evenly

dried pasteurised granules.

3. The drum itself has internal flights that lift

the sludge and allow it to fall through the

gas stream resulting in homogeneous

dried granules.

DDS – The principle



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Capacity up to 14.000 kg/h Water Evaporation (~ 20 t Sludge / h) per Line

Round shaped granulate with defined particle size due to backmixing process!

Convective drying; closed air loop for high thermal efficiency

Directly heated with primary heatsources (biogas, natural gas, diesel, LPG,..)

Andritz References: > 150 dryer worldwide

DDS – The Features



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• characterised by movement of the granules achieved by passing of the gas

stream through the product layer

• The granules become “floating” ( free floating ) and mixed thoroughly.

FDS - The Principle

Particle in floating motion



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Direct sludge feeding into highly turbulent fluidized bed

Small footprint of Dryer, Minimum Offgas Quantity

Indirectly heated with heating medium such as thermal oil or steam used in heat-exchanger

Heat recovery from condenser possible

Capacity up to 10.000 kg/h Water Evaporation

FDS – The Features



PICTURES

Contact Dryer (indirect) with heated

trough, shafts and paddles

Closed process chamber (no air)

Two counter rotating shafts

Wedges shaped paddles ensure

perfect local mixing and mechanical fluidization

No sweep gas / air intake

Low mechanical speeds – low wear

Overflow weir to keep filling degree inside machine

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GPD - The Principle



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GPD – The Features



Simple drying concept; Minimum Offgas Quantity

Partial Drying possible (65-90% DS)

Indirectly heated with heating medium such as thermal oil or steam used in paddles and shaft

Heat recovery from condenser possible

Capacity up to 6000 kg/h Water Evaporation per line

PICTURES

BDS - The Principle

1. Designed as belt conveyor in a casing. The drying gases are flowing through the

product layer distributed evenly on top of the belt.

2. By means of a slow moving belt the drying gases are enabled to

heat up the wet granulate and evaporate the water.

3. The granulate bed acts as a filter media to prevent dust generation

inside the dryer.


LVIV, Sludge Conference; 11 2015; ANDRITZ Separation14

Belt dryer for biomass.wmv

Belt dryer for biomass.wmv

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BDS – The Features



Low temperature heat-source possible (if cheap waste energy is available)

Stable and easy operation: low speed, low temperatures

Direct or indirect heated (primary energy sources or heating medium thermal oil, hot water,..)

Good product quality due to back-mixing process

Capacity up to 6000 kg/h Water Evaporation per line with standard sizes

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Natural gas/

Biogas

Sludge Cake

Waste heat

Thermal oil

Steam, etc.

Belt dryer

CondenserCirculation

Air fan

Mixing screw /

Mixer

To exhaust air treatment

Exhaust air fan

Wet sludge silo Belt cooler (Option)

Fresh air fan

Potable water

Final effluent

Waste water

Principle flowsheet of an Andritz BDS

Heat-

exchan

ger

Duct-

Burner

Heat-

exchan

ger

OPTION: Hot Water =

low Temp. heat recovery

Heat-

exchan

ger

Andritz Belt Drying System BDS


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Backmixing technology

• Formation of granules which result in a high quality and easy to handle product

• Homogenously dry product: drying process starts with a particle which already has a dry

core so DS is homogenouse and e.g. hygenisation can easily be guaranteed

• Excellent circumstances for drying: the mixture fed to the belt consists of numerous

granules therefore huge specific surface which enables an optimum saturation of drying

air, which results in an efficient drying process. Wet sludge is applied in a thin layer on

each particle which makes water vapor “transport” easy and not limiting.

• Flexibility in feed DS-content: fluctuations in cake DS are levelled out by the mixing

process.

• Even distribution of feed on belt: free flowing mixture ensures a even distribution and

best possible use of belt area

• No problem with sticky phase: dewatered sludge cake has problematic properties in the

range of approx. 40-60% DS. This can be overcome with backmixing.

Advantages:

90% DS Partially dry (backmixed)

Andritz Belt Drying System BDS


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Reference: Psyttalia, Greece

• Water evaporation: 4 x 8.625 kg/h

• Heat source: thermal oil

• Operation per week : 24 h / day, 7 days

• Final product: granulates > 90% DS

• Commissioning: 2007

Andritz Drum Drying System (DDS)

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Reference: Changi ( Singapore )

Andritz Drum Drying System (DDS )

Technical Data:

• Water evaporation capacity: 5x 11.000 kg/h

• Sludge input: 25 – 28%DS

• Heat source: diesel / bio gas

• Operation: 24 h / day, 7 days per week

• Final product: dried granulate > 90% DS


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Andritz Fluid Bed Drying Plant

• Water evaporation: 3 x 2.830 kg/hr

• Heat source: bio gas

• Operation per week: 24 h / day, 7 days

• Final product: granules 70 - 90% DS


Dryer workshop

Dryer building

Reference - Shanghai Bailonggang / China

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Andritz Fluid Bed Drying Plant

Reference: Bern2 / Switzerland

• Water evaporation: 3,430 kg/h

• Heat source: heating steam

• Operation per week: 24 h/day, 7 days/week

• Final product: granules >90% DS


During erection ( sludge silos )

Dryer building

References: Ambarli, Istanbul / Turkey

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ANDRITZ Paddle Drying System – GPD

Technical Data:

• Water evaporation capacity: 6x 3000 kg/h

• Sludge input: digested 25 %DS

• Heat source: flue gas


• Final product: dried product > 90% DS


Reference SMAT, Torino / Italy

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Technical Data:

• Water evaporation capacity: 2x 3500 kg/h

• Heat source: flue gas


• Final product: dried product > 90% DS

• Commissioning: 2007/2012

ANDRITZ Paddle Drying System – GPD

Reference - Hereke, Turkey

Technical Data:

• Water evaporation capacity: 8.150 kg/h

• Sludge input: 250 t/d ( 20%DS )

• Heat source: Waste heat from the cement kiln




Andritz Belt Drying Systems

Reference – Koszalin, Poland

Andritz Belt Drying Systems

Technical Data:

• Water evaporation capacity: 1500 kg/h

• Input dewatered sludge

• Heat source: natural gas




Thank you

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for your attention!

Klaus Trattner, MScSEPARATION

ANDRITZ AG

Stattegger Strasse 18

8045 Graz, Austria

Phone: +43 (316) 6902 2990, Fax: +43 (316) 6902 453

www.andritz.com

LEGAL DISCLAIMER

All data, information, statements, photographs, and graphic illustrations contained in this presentation are without any obligation to the publisher

and raise no liabilities to ANDRITZ AG or any affiliated companies, nor shall the contents in this presentation form part of any sales contracts,

which may be concluded between ANDRITZ GROUP companies and purchasers of equipment and/or systems referred to herein.

© ANDRITZ AG 2014. All rights reserved. No part of this copyrighted work may be reproduced, modified or distributed in any form or by any

means, or stored in any database or retrieval system, without the prior written permission of ANDRITZ AG or its affiliates. Any such unauthorized

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