TECHNICAL SESSION II 1 JUNE 2017

Transcription

1 TECHNICAL SESSION II 1 JUNE 2017 INNOVATIONS & IMPROVEMENTS: SUSTAINABLE, PERFORMANCE ENHANCING AND ENERGY SAVING SOLUTIONS Vacuum blower technology for Tissue plants - a case study for the most modern vacuum plant on Tissue machines in Brazil Wagner Canelhas Sales Engineer Turbomachinery & Reactors MAN, Brazil Wagner Canelhas is currently a sales engineer in the division of new equipment for turbomachinery and reactors at MAN Diesel & Turbo Brasil since He worked in advertising and marketing at Escola Estadual Adolpho Bloch between 2007 and Wagner worked as an art director in advertising at AB Comunicações in He graduated in Mechanical Engineering from Universidade Federal Fluminense in 2016, where he participated in the Formula SAE project for three years, in which he was responsible for the fairing of the vehicle and in parallel for the team s marketing management. He joined MAN as an intern in September 2014.

2 Vacuum blower technology for Tissue plants A case study for the most modern vacuum plant on Tissue machines in Brazil MAN Diesel & Turbo Wagner Canelhas Sales Engineer Rafael Martos Head of Sales MAN Diesel & Turbo [optional: Brand] Author Current topic < 1 >

3 Introduction Part 1 Introduction - Paper Machines - Tissue Machines - Hood - Felt Wires - Vacuum levels and flow rates for each product - Typical vacuum flowchart Vacuum Systems for Tissue - Liquid ring pump - Main Components - Operating characteristics - Use of "False Air" - Vacuum blowers - Main Components - Operating characteristics - Comparison between systems - Advantages and disadvantagess - Case study for a Tissue plant - Water separation system < 2 >

4 Introduction Part 2 Technological characteristics - Energy Efficiency - Constant Speed - Variable blades - Multiple levels of vacuum - Speed variation - Thermal Recovery Possibilitie - Hood inflation air - Shower water heating - Building heating / false ceiling - Combustion air preheating - Felt Conditioning - De Costa curves (constant drainage) - Break-in and drag-load phenomena - Measurement and control of dewatering Modernizations of existing plants - Typical vacuum flowchart - Modernizations list of references Conclusion < 3 >

5 Vacuum levels for other applications Usually Tissue is one of the processes that most demand vacuum in single points Type of produced paper Anual production (tons/year) Vacuum gauge pressure (meters of water column) Total vacuum flow (m³/min) Maximum vacuum flow (m³/min) Tissue ,5 até -5,0 920 Suction Roll Tissue ,5 550 Single Point Pulp ,5 até -6,5 900 Suction roll Paper ,2 até -7, Press Roll Paper ,5 até -7, Uhle Box < 4 >

6 Vacuum systems for Tissue Liquid ring pumps Components: A Rotor with blades B Liquid ring seal C Pump housing D Suction section E Discharche section F Interface blades / liquid ring Additional Details: Air and water inlets and outlets Bearing support Single or dual stage operation One motor for multiple pumps Pulleys configuration < 5 >

7 Vacuum systems for Tissue Characteristics of pumps at constant speed System features: Volumetric machine Pulsations and vibrations High pressure variantions High vacuum levels (>80 kpa) Small to medium lifetime Requires water sealing Low flow variation Works under Bleed Air Low maximum flow per housing High number of pumps per installation (>4) Lower compression efficiency Small change in consumption under partial loads Vacuum Power Bleed air V = Cte Air Flow Suction point < 6 >

8 Vacuum systems for Tissue Vacuum blower Components: Rotor and impeller(s) Stator Housing Hydrodynamic bearings (oil) Up to 4 suction points Rotor Housing Additional Details: Single or multiple stages One motor per machine One blower for multiple vacuum machines Dedicated lubrication system Diffuser blades Gearbox Stator Hydrodynamic bearings < 7 >

9 Vacuum systems for Tissue Characteristics of blowers at constant speed System features: Dynamics machine Low pressure variation Delivers until 4 pressure levels Throttle valves Pressure levels up to 80 kpa Long lifetime, exceeding 15 years Compresses air only High compression efficiency High flow variation 110 to 80% for RC technology 110 to 30% for RT technology Few machines per installation For Tissue, from 1 to 4 machines Economy in partial loads Possibility of complementary thermal recovery Vacuum Power P = Cte Air Flow Suction point < 8 >

10 Comparison between technologies Advantages and disadvantages Application / Feature Vacuum blower Liquid ring pump Operating flow rate per equipment Higher flow rates Lower flow rates Operating pressure range Up to 80kPa Up to around ~98 kpa Pressure variation Low: Throttle valve High Flow rate variation High Low: Bleed air Number of machines per Tissue plant 1 to 3 4 or more Compression efficiency High Low Possibility of thermal recovery High - Exhaust air Low - Warm Water Water consumption Very low High Vibrations and pulses Low High Dimensions and weight Low High Noise level Similar Availability Higher Lower Maintenance requirements Low Frequent < 9 >

11 Comparison between technologies Air / Water separation system Vacuum pumps: Separators with barometric legs Pre-separator packages One separator per vacuum point Open or closed water cycle for sealing system Cooling towers Vacuum blowers: At least one separation box per vacuum level (pressure) Concrete or steel boxes Positioning on the same level as the paper machine or lower Pumps for water extraction < 10 >

12 Case Study - Tissue Plant Comparison of new Tissue plant in Brazil Rated item Vacuum blower Liquid ring pump Rated power (electric motor) 57% (43% reduction) 100% Maximum power consumption 50% (30% reduction) 80% Average power consumption 40% (40% reduction) 80% Number of machines 1 x RT vacuum pumps Preliminary thermal recovery 14 % (86% reduction) 80% OPEX / LCC 55 % (45% reduction) 100% Water consumption in open circuit < 1% (99% reduction) 100% For this project the blowers consume, under average power, half the power of the pumps First reference of the single-stage machine in Brazil Forecast to have already started operation in 2019 Largest Yankee Cylinder ever made for Tissue machines in the world Taken as the most modern Brazilian vacuum plant in Tissue Effects of Break-in economy were not considered in this study < 11 >

13 Vacuum Blowers Energy efficiency - constant speed < 12 >

14 Vacuum Blowers Adjustable diffusor blades Functionality: Modify the flow resistance and alter the machine operating curve Provide modulation of flow and pressure of the machine Maximize operation during felt conditioning and llifetime Additional data: Diffusor blades can operate between 10 to 26º Operated by pneumatic valve and servo motor integrated into the casing Allows reduction of project flow by up to 30% Automatic system < 13 >

15 Vacuum Blowers Energy efficiency diffusor blades < 14 >

16 Vacuum Blowers Energy efficiency diffusor blades < 15 >

17 Vacuum Blowers Energy efficiency Speed variation < 16 >

18 Felt conditioning Constant drainage De Crosta curves De Crosta curves (1980) The drainage rate of the felt should be constant during the lifetime of the felt. Study on new, used and half-life felts Conclusion of the ideal vacuum curve for paper machines Lifetime (30 days) Transition to old felt (5~7 days) Known phenomena: Break-in Time spent on felt compaction Drag Load Higher load on machine rolls Risk of premature felt rupture < 17 >

19 Felt conditioning Comparison of vacuum technologies < 18 >

20 Felt conditioning Possible solutions Ideal solutions Measurement of the level drainage of felts and automation of the vacuum system Drive in the vacuum system making use of choke valves and diffusing blades reducing the effects of Break-in Variation of flow to lower values than design, reducing drag-load effect Usual solutions Chemical or mechanical compaction of felts at the beginning of their useful lifetime Low production operation to compensate for operation outside the design point of the vacuum system < 19 >

21 Thermal recovery Theoretical Principle - Preliminary Calculus Enthalpy of moist air Considerations for thermal exchange at constant pressure (specific heat c p ) Consider absolute humidity to calculate the enthalpy of water separately Consider enthalpy of dispersed water steam in air h = c air T + x (c water T + h steam ) Case Study for Tissue Machine Temperature that the air leaves the blower ºC Ideal thermal recovery temperature for air - 60 C Consideration of specific heat of water as 1.84 kj / kgºc Consideration of specific heat of air as kj / kgºc Consideration of steam enthalpy as 2501 kj / kg Absolute humidity of 0.15 kg H2O / kg air Mass flow rate of 25 t / h = 25,000 / 3600 kg / s Result obtained: 798 kw of energy to be recovered Added to energy efficiency, savings of 80% compared to the consumption of vacuum pumps < 20 >

22 Thermal recovery Hood air - Simplified < 21 >

23 Thermal recovery Hood air vent preheating < 22 >

24 Thermal recovery Hood air - burner < 23 >

25 Thermal recovery Hood air Steam heated < 24 >

26 Thermal recovery Pre-Heating of the shower water < 25 >

27 Thermal recovery Building heating / False ceiling Building heating Relevant in regions of southern Brazil, where winter is severe and heat energy can be saved by using blower air to heat the building. It can be applied in a complementary way to the previously proposed recoveries. No use of heat exchangers False ceiling heating In order to avoid precipitation of droplets in the ceiling where the paper machine is installed, it is common to construct a heated false ceiling. Application will largely vary according to present temperatures, size and production of the paper machine in question. It can also be applied as thermal recovery complementary to previous ones No use of heat exchangers < 26 >

28 Thermal recovery Preheating of combustion air < 27 >

29 Modernization of existing plants Proposed adaptations What is, or can be kept Vacuum pump system (temporary backup) Air / water pre-separators Vacuum pipeline between pumps and paper machine What shall be implemented: New vacuum system (blowers) New motors for blower drive Separation boxes made of concrete or steel Control valves at the point of greatest flow and pressure. Opcional Frequency inverter Transformers < 28 >

30 Modernization of existing plants Common operation - List of world references Plant Customer Product Country Year Archangelsk BM2 JSC Arkhangelsk Sack Kraft Paper Russia 2016 Shiwha Shindaeyang BM1 Shindaeyang Paper Linerboard Korea 2015 Shintanjin PM 1 Hansol Paper Co. Ltd Art Paper Korea 2015 Oberkirch PM 5 Koehler Paper Group Paper Germany 2015 Duffel TAD Tissue Sofidel Benelux NV. TAD Tissue Belgium 2015 Osan BM 1 Dong Won Paper C. Ltd Testliner Korea 2015 Daejeon BM 31 Hansol Paper Co. Ltd White Board Korea 2015 Daejeon BM 32 Hansol Paper Co. Ltd White Board Korea 2015 Ovaro BM 1 & 2 Reno di Medici Board Italy 2015 Ansan Korea BM 1 Korea Paper Linear Board Korea 2014 Dörpen PM 3 UPM Nordland Fine Paper Germany 2014 Lexington NW 1 Kimberly-Clark Non Woven USA 2014 Banpong PM 3 Thai Paper Printing/Writing Thailand 2014 Hyunpoong BM 1 Kyungsan Paper Corrugated Medium Korea 2014 Nortrup BM 1 Delkeskamp Fluting/Liner Germany 2014 Mislata PM 7 Miquel y Costas & Miquel Silk/Tipping paper Spain 2014 Olsany PM 5 OP Papirna Finepaper Czech Republic 2013 Beech Island TM 3 Kimberly-Clark Tissue USA 2013 Allo TM 1 Georgia-Pacific Company Tissue Spain 2011 < 29 >

31 Conclusion Vacuum blower technology It has several advantages for the papermaking process, especially in the sanitary paper sector (Tissue) Tendency to expand and spread in Brazil (as already happened in China) Modernization studies being done in several plants and obtaining good results with returns of the investment between 1 to 3 years. Vacuum pump technology Ideal for high vacuum levels and applications where fluid sealing is crucial. More competitively efficient in small plants when fewer pumps are applied (<400 cfm) Especially used in large scale in pulp mills (less concern with water consumption and thermal recovery, besides own electrical generation) Thermal recovery technologies Great application potential, however reduced when compared to countries with severe winters May be associated with generation solutions with gas and steam turbines < 30 >

32 Vacuum blower technology for Tissue plants A case study for the most modern vacuum plant on Tissue machines in Brazil MAN Diesel & Turbo Wagner Canelhas Sales Engineer Rafael Martos Head of Sales MAN Diesel & Turbo [optional: Brand] Author Current topic < 31 >