The Heat robbers ! 100% fuel energy 80% steam 3% distribution losses 77% Process consumption 57% 20% Unburnt Stack Blowdown (Condensate & Flash)

How does one measure Specific Energy Consumption ? -kg of fuel per kg of Paper -kg of steam per kg of Paper or kg of Steam/kg of water evaporated -Kw-h / Tonne of Paper -Kcal/ kg of water evaporated? -Total equivalent Energy/ Tonne of Paper ? Gj/Tonne of Paper? Energy Management Seminar for Vietnam Paper Mills, Ho Chi Minh City, May 2008

How does one Reduce Specific Energy Consumption ? -Obviously minimise the Losses ( Boiler losses, Distribution losses) - Enhance Condensate Return & Recover Flash Steam - Improve the Process heat Utilisation ( Heat Transfer rate) EPIC Educational program – Saving Energy Cost by increasing Boiler and Steam system Efficiencies

Specific Steam Consumption on Indian Machines Which is more representative ? Kg of steam / kg of Finished production OR kg of steam /kg of water evaporated ? Typical good values Newsprint Wr/Pr (NS) Wr/Pr (SS) Kraft Paper Board Tissue Kg of steam/ water =

Basic Principles of reducing energy consumption Reduce Temperature of any exhausts in Boiler House Minimise Amount of water evaporated in drier section Minimise Steam condensed outside driers Maximise Condensate return and pressure Minimise Electrical consumption of drives/pumps Monitor and Manage Energy Consumption trends & costs.

The No.1 Rule for energy conservation You cannot control what you cannot measure

Factors affecting Specific Steam consumption..1 Furnish Type Stock Freeness Dryness off Press Stock Temperature Felt tensions Paper breaks/idling No. of Driers /Material Design of steam and condensate system Condensate evacuation efficiency Extent of Flash steam recovery Type of Siphon/clearances Presence of non condensibles/air

Factors affecting Specific Steam consumption….2 Type of Hood and Controls Hood doors open/closed Sizing of Thermocompressors Differential Pressures across Driers Number of driers connected to Condenser Finally the Degree of Automation

Need for Automation in Steam Systems Upgrade to Efficient Steam /Quality Control systems. The Need to Produce High Quality Paper The Need to run machines faster The Need to minimise Cost of Manufacturing The need to jump productivity and Energy efficiency All of these have forced mills to look at improving their systems and Automation is one of the strategies.

Specialist in process efficiency & energy conservation Steam Generation -- Minimum Cost of Steam generation 5 Monitoring real time Efficiency of the Boiler Tracking Losses in Boiler Both Direct and Indirect Efficiency Steam to Fuel Ratio for Different Loads Online Excess Air control Boiler House Management system with objective to minimise steam generation cost

Specialist in process efficiency & energy conservation Steam Distribution – Minimising Losses Delivering Steam at the Right Pressure and Temperature to Paper machine is essential Steam should be Dry Saturated at Drier Inlets This means that Steam conditioning is essential Minimising Pressure Drops in lines Correct Drain Trapping is essential to prevent steam wastage.

Specialist in process efficiency & energy conservation Steam Utilisation- Energy Efficiency of Paper Machine Drying Paper Uniformly at normal steam pressures Removing Condensate from Driers efficiently Returning Condensate to Boiler house Flash Steam Recovery Steam Response to Final Moisture Value

Heat Transfer in Cylinders SteamAir gapPaper Felt Cylinder CondensateAir layer MoisturePaper sheet Steam in Condensate out Condensate inSiphonDrier

Needs for Efficient Steam and Condensate system Steam at the Right Pressure, Saturated and Dry Correct syphon selection and clearance Adequate Differential Pressure Venting of Non- condensibles/Air 100 % Recovery of Flash Steam/ Blow thru Minimising leakages thru rotary joints Adequate Thermal insulation Adequate Steam Trapping on distribution lines

Roll Cylinder PV Ventilation Felt Hood & Pocket Ventilation- Automation for Efficient operation Hood & Pocket Ventilation- Automation for Efficient operation

Specialist in process efficiency & energy conservation Hood & Pocket Ventilation- Controls Controls Hood provides Consistent Drying environment Hood also provides Energy efficiency % saving in Steam is possible using Closed Hoods Pocket Ventilators can increase production by 5-8% Controls for : a) Pocket Ventilation Temperature Control b) Dew Point Control /Exhaust Humidity c) Zero Level Control for minimum leakage air.

The Link Between Steam and Quality Specialist in process efficiency & energy conservation Uniform Drying is possible only with a Stable steam and condensate system. Poor Moisture profiles can result due to Poor condensate evacuation or poor Hood /PV air circulation apart from others Popereel Moisture controlled by Steam Valves in Drier Section

Where do we begin ? The Small Things –Check for leaking traps and replace immediately –Check Syphon tips and clearances –Check for Rotary Joint seal failures /leakages –Check for excessve DP set points –Check for obvious leakages –Check Excessive Steam pressure –Install Airvents and sightglasses The Larger things Leading to Automation –Control Exit moisture from Presses –Installing Thermocompressors –Control Valve and DP automation –Changeover to correct syphons –Install Drier Diagnostic systems –Hood controls First Start with installing accurate meters for Steam /condensate/electricity

Mathematical Model & Simulation Software of Paper Drying process

Parameters Monitored & to be Controlled: Surface Temperature of dryer cylinders Temperature of paper sheet Moisture content of paper sheet Evaporation rate of water from the paper surface Comparison of Measured parameter value with Set- Point generated by DryMax Paper In Controller Paper Out Steam Condensate DryMax

Summary Specialist in process efficiency & energy conservation Automation pervades every aspect of Steam in a Paper Plant To operating Efficient Boilers To World Class Steam and Condensate systems of Paper machines To Energy Efficient Hoods and PV systems To Robust Quality Control systems integrated with Steam systems

Whatever be the Automation…….. Specialist in process efficiency & energy conservation The Ultimate Objective is to have the Lowest Specific Steam Consumption for your plant Is your Plant close to world class levels of Energy Efficiency ?