1. Mass flow-based controls with solids measurements reduce sludge handling costs  
Heli Karaila Valmet
Suleyman Gemici Valmet
Lauri Valtiala Tampere Water

2. Valmet in brief Valmet’s unique offering : Process- technology
Valmet is the leading global developer and supplier of technologies, automation and services for the pulp, paper and energy industries.
Our professionals around the world work close to our customers and are committed to moving our customer’s performance forward – every day.
Valmet’s net sales in 2016 were approximately EUR 2,9 billion, Valmet’s head office is in Espoo, Finland and its shares are listed on the Nasdaq Helsinki Ltd.
Valmet’s unique offering :
Process technology, Automation & Services
Customer
Process-
technology
Luvut Prospectuksesta
ENE oli sisällä
Selkeytetty alaotsikko
Asiakkaiden lukumäärä sama kuin viime vuonna
Services
Automation
2017
© Valmet |

3. Valmet Automation business line overview
Extensive range of process automation and information management solutions to take our customers’ business performance forward
Global network of expertise close to our Customers
Strong R&D investments across the automation offering
The Valmet Automation business serves customers in pulp and paper, wastewater and other process industries, power generation and marine .
Global market leader with #1 market position in pulp and paper
Industry-leading product portfolio
Comprehensive services
Figures 2015
Net sales EUR 309 million
Orders received EUR 309 million
Employees ,600
Automation
1,600 automation professionals
> 500 services engineers
450 own operations people
Luvut Prospectuksesta
ENE oli sisällä
Selkeytetty alaotsikko
Asiakkaiden lukumäärä sama kuin viime vuonna
2016
© Valmet | Automation Business Line

4. Tampere Viinikanlahti wastewater plant Finland
Tampere Viinikanlahti wastewater plant treats municipal and industrial wastewater 70 – cubic meter daily
There is produced about cubic meter sludge yearly based . The dewatered sludge is used in agriculture, landscaping, road bank covering, and landfill sites.
The process has mechanical, biological and chemical treatment phases
Biogas of the 2 digesters is used as electricity in the plant
22 September, 2018
© Valmet | H.Karaila / Case Tampere Water Viinikanlahti Finland

5. Based end customer feedback laboratory measurement is not enough
Quality control of
centrate water
based on infrequently taken lab samples
is not adequate
mg/l
Valmet LS Laboratory
Lab sample represents centrate quality at that specific moment:
- After a half an hour the situation can be completely different!
mg/l
Valmet LS Laboratory
Valmet LS Laboratory
©Valmet

6. Tampere Water Viinikanlahti wastewater treatment plant with Valmet’s solids measurement (TS, LS and DS) locations and Valmet SDO
22 September, 2018
© Valmet | Author / Title

7. Valmet SDO project started autumn 2015
Valmet SDO with Valmet TS, Valmet LS and Valmet DS measurements
Viinikanlahti wastewater plant ordered Valmet SDO , sludge dewatering optimizer autumn 2015 for one of their centrifuge.
In the same time the plant wanted to optimize also primary sludge pumping as well the sludge feed to the digester based on solid measurements
At the centrifuge end customer wanted specially to minimize centrate solid amount and also the dry cake solid amount should be in the optimized level in order to minimize the transporting costs. Also polymer selection and optimizing of the polymer usage was one target value.
The project started September 2015 and
end customer accepted the delivery
January 2016
22 September, 2018
© Valmet | H.Karaila / Case Tampere Water Viinikanlahti Finland

8. Valmet SDO, Sludge Dewatering Optimizer
Centrifuge application
Centrifuge: Removes solids from water by way of centrifugal force.
The Dry Cake target value varies but usually cake solid is in the 12– 35% range. It is important that the Dry Cake solid amount as high as possible in order the transport costs and incineration costs are optimized
Reject water / Centrate solids amounts needs to be minimized in order the material is not circulating inside the plant and cause capacity as well polymer and dewatering costs .
The centrifuge controllable variables are
torque of centrifuge
polymer dosing
Centrifuge depended items are max
massflow, sludge consistency
and volumetric flow to the centrifuge
What kind of and how many dewatering units end customer has ? How end customer control the dewatering process ? How end customer control the polymer amount ? Torque control of the centrifuge ?
22 September, 2018
© Valmet | H.Karaila / Case Tampere Water Viinikanlahti Finland
©Valmet

9. Total solids measurements portfolio
Valmet TS
Total solids measurements portfolio
Valmet Total Solids Transmitter, Valmet TS, microwave based measurement for
Measuring Total solids 0…40 %TS (vs. opticals 0…4%TS)
sludge sedimentation, digestion, fermentation
sludge pumping and treatment applications
dewatering, preheating
chemical dosing (polymer)
dry cake transporting costs, incineration
Valmet Low Solids Measurement, Valmet LS, LED based measurement for
Measuring Total Suspended Solids 0…0,5 %TSS
Optimizing
selection of correct polymer type
polymer dosage
centrifuge capacity and runnability
internal solids cycle management of the plant
Valmet Dry Solids Measurement, Valmet DS, microwave based measurement for
Measuring Total Solids 15…35 %TS
Dry cake transporting costs, incineration
Valmet LS
Valmet DS

10. Modular Application structure
SLUDGE DEWATERING APPLICATION
Centrate value feedback + polymer optimization
Sludge dry mass feed to centrifuge
Dry Cake TS control
Torque
Polymer
Flow
Sludge feed flow
The application structure is modular. It is possible to go on steps by step. This is how the whole application scture looks like. The centrifuge process is controlled with the inlet mass flow to the centrifuge as well as centrate and dry cake values are optimized.
Inputs Values:
Valmet TS before the centrifuge
Flow measurement before the centrifuge
Valmet LS at the centrate,
Valmet TS at the dry cake
Output values:
Polymer setpoint
Torque setpoint
Sludge feed flow setpoint
©Valmet

11. Centrate TSS Dry Cake TS interactions
Manipulated variables
Polymer
Torque
Centrate TSS
Controlled variables
Dry Cake TS
Difficult to control with separate loops , easy with Valmet SDO MPC technology
©Valmet

12. Valmet SDO / Example of the operator display

13. In one year of operation, the measurements and control have proved to be very reliable
Valmet TS
Valmet LS
Valmet DS

14. More than 140,000 €/year savings
 Sludge pumping from clarifiers reduced from 76 m3 to 50 m3 an hour
Reduced excess water to thickening
Energy savings are approx. 37 %, 5,000 €/year
Digester solids increased from earlier 3.5% to 5%
32 % less sludge to treatment
Increased biogas production
Solid content of centrate water is now 50 % lower and more stable
Polymer consumption has decreased almost 40 % from level 8 kg/ton
Savings with less material circulated, 10,000 €/year
Polymer savings, 49,000 €/year 
Easy to dopolymer tests
Dried cake solids content has increased by about
1-2 % from 29,7 % to over 31%
Saving in transportation costs approx. 80,000 €/a