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Learn how to save energy with efficient vacuum pumps and system design. Explore topics such as measurement and monitoring of vacuum pump efficiency, paper machine vacuum system design, and case studies. Join Mukesh Kumar from Gardner Denver Nash at the IPPTA Zonal Seminar in Chandigarh on July 13-14, 2006.
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Save Energy with Efficient Vacuum Pumps & System Design Mukesh Kumar Gardner Denver Nash IPPTA Zonal Seminar: July 13-14, 2006 Chandigarh
Topics • Liquid Ring Vacuum Pump System • Measurement and Monitoring of Vacuum Pump Efficiency • Paper Machine Vacuum System Design • Case Studies
Liquid Ring Vacuum Pump System Liquid Ring Vacuum Pump Positive Displacement Technology Constant Volume, Variable Vacuum
Liquid Ring Vacuum Pump System • Common Characteristic of the Papermaking Process is Constant • Change: • Changes in Paper Grade and Basis Weight • Changes in Felt Permeability due to Felt Life • Changes in Freeness • and many other changes • Liquid Ring Vacuum Pump System is Best Suited to Cope with • above Changes
Liquid Ring Vacuum Pump System Changes in Paper Grade and Basis Weight Liquid Ring Vacuum Pump System is Best Suited to Deal with Changes Caused by Grade Variation
Liquid Ring Vacuum Pump System Changes in Felt Permeability Liquid Ring Vacuum Pump System Will Be Able to Achieve Good Results Despite the Changes in Felt Permeability
Liquid Ring Vacuum Pump System Typical Mill Installation
Liquid Ring Vacuum Pump System Reliable and Efficient Overall Efficiencies: 0.9 KW/CMM Most Common
Measurement & Monitoring of Vacuum Pump Efficiency Vacuum Pump Efficiency is Practically Expressed in Terms of KW/CMM Fading Vacuum Level is usually First Sign of Loss in Efficiency of Vacuum Pump
Measurement & Monitoring of Vacuum Pump Efficiency • Capacity Testing • Single or Dual Plate Orifice Method • Manufacturer Test Methods: HEI or Pneurop • Video Inspections
Measurement & Monitoring of Vacuum Pump Efficiency • Single or Dual Plate Orifice Method • Suitable for Mill Site • Accuracy Level: +/- 10% Dual Plate Single Plate
Measurement & Monitoring of Vacuum Pump Efficiency Manufacturers Test Methods: HEI (USA) or Pneurope (Europe)
Measurement & Monitoring of Vacuum Pump Efficiency • Video Inspections • Very Useful for Inspecting Internal Condition of the Pump • Generally Recommended for Large Pumps Old Pump Showing Badly Worn-out Rotor Blade
Paper Machine Vacuum System Design Vacuum Piping Many Problem Often Originate in the Piping System • Key Design Considerations • Recommended Velocities: • Wet Air : 3500 FPM • Dry Air : 5500 FPM • Use ACFM Values for Air Volume • In case of Border Line Selection Use • Next Higher Size Pipe • Vacuum Piping Containing Liquid • Must Run Slope Downward
Paper Machine Vacuum System Design Consequence of Incorrect Pipe Sizing: Practical Example Required Air Flow: 3000 ACFM @ 15” Hg Vacuum Loss due to undersized pipe: 5” Hg Vacuum Required at Vacuum Pump: 20” Hg P1V1= P2V2 (ignoring temperature) P1 = 30-15= 15” Hg A (at application point) P2 = 30-20 = 10” Hg A (at the pump) V2 = 3000 ACFM measured at Vacuum Pump 15 x V1 = 10 x 3000 V1 (available at application point) = 2000 ACFM !!!!
Paper Machine Vacuum System Design • Pre-Separators • Must Whenever Carryovers are Expected • Help Reduce Electrical Load on Pump • Prolong the Pump Life • Help Reduce Pipe Size after the Separation • Make Close Loop Re-Circulated Seal Water System Feasible • Types • Barometric Separator • Separator Tank with Extraction Pump
Paper Machine Vacuum System Design Barometric Separator Used for Elevated Applications L = 1.13 ft x (Vacuum in inch Hg) + 3 ft
Paper Machine Vacuum System Design Separator Tank with Extraction Pump Used for Low Level Applications Example: Bottom Felts Require Centrifugal Pump with Very Low NPSH Capabilities
Paper Machine Vacuum System Design Discharge System Discharge System is Often a Neglected Area Overloading is a Common Problem in Older Machines • Key Design Considerations • Recommended Velocities: • Wet Air: 3500 FPM • Separation: 500 FPM • Exhaust Air: 8000 FPM • Avoid Overloading as it • creates back pressure & • excessive noise • Back Pressure < 1 Psig
Case Study #1: Paper Mill in India Production Capacity: 60 TPD (Two Paper Machines) Paper Grade: Fine Paper Action Taken: Replacement of one Local Make Vacuum Pump by Original Nash CL2002 Pump in 1997 Duty Conditions: Air Capacity: 52 M3/min, Vacuum Level: 450 mmHg Old Pump Details: Absorbed Power-63 KW, Motor-75 KW Nash CL 2002 Pump Details: Absorbed Power- 47 KW, Motor- 55 KW Power Saving: 25% Payback Period: Less than One Year This mill eventually replaced 5 Nos. locally made pumps by Nash pumps gradually and ordered Nash Pumps for new project in 2005.
Case Study #2: Paper Mill in India Production Capacity: 150 TPD (Three Paper Machines) Paper Grade: Fine Paper Action Taken: Replacement of one Local Make Vacuum Pump by Original Nash CL2002 Pump in 2000 Duty Conditions: Air Capacity: 51 M3/min, Vacuum Level: 510 mmHg Old Pump Details: Absorbed Power-65 KW, Motor-75 KW Nash CL 2002 Pump Details: Absorbed Power- 48 KW Power Saving: 25% Payback Period: Less than One Year This mill eventually replaced 5 Nos. locally made pumps of various sizes by Nash pumps gradually and ordered Nash Pumps for new project in 2006.
Save Energy with Efficient Vacuum Pumps & System Design Mukesh Kumar Gardner Denver Nash IPPTA Zonal Seminar: July 13-14, 2006 Chandigarh