Anthony RossInfrared Imaging of Black Liquor Droplets

Team Members:Aaron Brandt

Will Carter

Brent Illingworth

Matt Travis

Academic Advisor:Dr. David Sailor

Industry Advisor:Dan Higgins, P.E.

Background

• Kraft paper pulping process schematic

White Liquor

Steam

Smelt

Weak Liquor

concentratedBlack Liquor

E-1

E-2

E-3

E-4 E-5E-6

P-1 P-2 P-3 P-4

P-5P-6

Pulp Digester

Evaporator Evaporator Evaporator

Recovery Boiler

Causticizer

P-7

Air

Combustion consumessolids

Sodium returned to NaOH and NaS

Schematic of Pulping Process

E-7

P-8

P-9

Turbine

Mission

• Design an optical assembly • Images are used to generate data• Data is used to improve boiler model

Project timeline

ID Task Name Start Finish DurationJan 2005 Feb 2005 Mar 2005 Apr 2005 May 2005

1/2 1/9 1/16 1/23 1/30 2/6 2/13 2/20 2/27 3/6 3/13 3/20 3/27 4/3 4/10 4/17 4/24 5/1 5/8 5/15 5/22 5/29 6/5

1 4w1/28/20051/3/2005PROJECT DESIGN SPECS.

2 3.2w2/18/20051/28/2005INTERNAL / EXTERNALSEARCH

3 5w3/11/20052/7/2005CONCEPT GENERATION

4 7.2w3/28/20052/7/2005OPTICS DESIGN

5 2.8w2/24/20052/7/2005ACTUATION DESIGN

6 5w3/28/20052/22/2005HOUSING DESIGN

7 6.8w4/8/20052/22/2005SELECTION & EVALUATIONOF FINAL DESIGN

8 1.2w3/1/20052/22/2005WINTER QUARTER REVIEW

9 4.4w5/9/20054/8/2005PROTOTYPING

10 2.2w5/23/20055/9/2005TESTING & VERIFICATION

11 2.2w6/6/20055/23/2005FINAL REVIEW &OPTIMIZATION

12 2w6/10/20055/30/2005FINAL PROJECTPRESENTATION

Existing sizing techniques

Laser – Detector Systems

• Laser passes through spray

• Photodetectors gather scattered light

Existing sizing techniques cont’

Imaging systems

• Light focused onto CCD to produce digital image

• Software analyzes images and outputs size

• Distance to droplets must be known

Sizing technique to be used

Infrared imaging system

• Other systems infeasible

• Camera currently used for maintenance

• High contrast due to temperature difference

• Additional marketability of IR camera

Major requirements

• Depth of focus must be short enough

• Focal length must be adjustable and known

• Viewing angle must be adjustable

• Adequate cooling and cleaning

Depth of focus must be short enough

• Software will only measure droplets that are in focus• Focal length can accurately be used as the distance to

droplets• Optics aperture affects depth of focus

Focal length must be adjustable and known

• Exact measurement region is unknown

• Needs to adapt to different boiler configurations

• Must be known to scale droplet image size to actual size

• Affects depth of focus & magnification

Focal length adjustment

• Dual lens system allows for focus adjustment

• Fine adjustment of rear lens necessary

Viewing angle must be adjustable

• Optics system will be inserted above spray

Viewing angle must be adjustable

• Mirror based system

• Fiber optics based system

Fiber optic imaging

Fiber bundles• Flexible• Coherent• Light entering and exiting must be parallel• Many components available

Viewing Angle Adjustment

• Bracket assembly

• Planetary gear assembly

Cooling/Cleaning

• Compressed air on sight

• Safe to use in boiler

• Air purge system for lens cleaning

• Air flow limited by compressed air pressure

• One or two air ports could be used

Decision Matrix

Future considerations

• Optics system– Dimensions– Calibration– Depth of focus– Utilize manufacturer expertise

• Cooling system– Detailed analysis

• Thermal expansion– Material selection

Conclusion

• Existing sizing methods analyzed

• Infrared imaging confirmed as most feasible

• Major requirements established

• Possible solutions compared

• Overall concept decided

Complete Concept

Questions?