final report on the multiport dryer - Argonne National Laboratory

More documents

Recommendations

Info

Figures1 Resistances to heat transfer on cylinder dryer.............................................................. 42 Percentage contribution rates of heat transfer resistances............................................ 53 Schematic representation of multiport cylinder dryer concept..................................... 74 Digital picture of multiport dryer heat transfer test apparatus ..................................... 95 Schematic representation of multiport cylinder dryer heat transfer test apparatus ...... 106 Detailed schematic representation of test section......................................................... 117 Heat loss, based on single-phase heat transfer tests, as a function of temperaturedifference between wall and ambient ........................................................................... 208 Average condensing heat transfer coefficients as function of mass flux ..................... 229 Average condensing heat transfer coefficients as function of pressure ....................... 2310 Local condensing heat transfer coefficients as function of quality .............................. 2311 Temperature distribution .............................................................................................. 2412 Two-phase pressure gradient as function of mass flux ................................................ 2413 Average condensing heat transfer coefficients of multiport and conventionalcylinder dryers .............................................................................................................. 2614 Increased drying rate as a result of multiport technology ............................................ 27Tables1 Value/range of experimental parameters...................................................................... 21A1 Energy savings and decreased CO 2 emissions by Multiport Dryer technology .......... 38iv
DESIGN AND DEMONSTRATION OF MULTIPORT CYLINDER DRYER:FINAL REPORT ON THE MULTIPORT DRYER PROJECT IN PHASE 1byS. U. S. Choi, W. Yu, M. W. Wambsganss, T.-H. Chien, J. Harkness,D. M. France, D. K. Barde, W. D. Vallance, C. W. Stewart, and J. L. TimmABSTRACTThe rate of paper drying is one of the critical technical barriers in the production of pulpand paper. The concept of multiport cylinder dryers developed by Argonne National Laboratoryis an innovative idea that could create breakthroughs in the drying of pulp and paper. In amultiport dryer, steam flows through “ports,” or longitudinally oriented passages, close to thedryer surface. This design, which minimizes the “rim of condensate” and offers a larger surfacearea for drying, thereby increasing the drying rates, also uses forced heat convection, which ismore effective as a heat-transfer mechanism than heat conduction in the conventional dryerdesign. The feasibility of this novel concept was demonstrated in a proof-of-concept test.Experiments were performed in a specially designed apparatus to investigate the condensing heattransfer characteristics of a single channel that is representative of a multiport dryer (MD) undertypical operating conditions. The experimental results showed that multiport-cylinder-dryertechnology provides very high heat-transfer coefficients of 15,000 W/m 2·K (2,600 Btu/h·ft 2·°F)and a highly uniform distribution of cylinder-wall temperature. Laboratory-scale tests andassessments suggest that a multiport cylinder dryer can potentially increase paper drying orproduction rates by as much as 20% when compared with spoiler bar technology, and by asmuch as 90% when compared with existing technology without spoiler bars. The increaseddryer efficiency translates into either a reduction in the number of dryers at the same level ofproduction or an increase in the rate of production with the same number of dryers. Multiportdryer technology is important to the pulp and paper industry because it will have a major impacton improved productivity and capital effectiveness. This innovative approach can be used toretrofit existing dryers or to reshape next-generation new dryers.Phase 1 of the MD Project has successfully demonstrated the feasibility of the concept.However, the practical effects of a full-scale model MD are still unknown, and so MDperformance tests in a full-scale, rotating test dryer will be conducted in Phase 2 of the MDProject.
Page 1: ARGONNE NATIONAL LABORATORY9700 Sou
Page 6 and 7: 21 INTRODUCTIONThe pulp and paper i
Page 8 and 9: 4A B C D EF G HA - Steam convection
Page 10 and 11: 6In some cases, spoiler bars have b
Page 12 and 13: 8The structure of the multiport cyl
Page 14 and 15: 10TpSICAFMITemperaturePressureSight
Page 16 and 17: 12Nine Type-K thermocouples (T a,T
Page 18 and 19: 14D. After-condenser heat dump.The
Page 20 and 21: 165.2 ShutdownA. Turn off all Multi
Page 22 and 23: 18∆qh(z) =s(z)∆A s [ T s(z) −
Page 24 and 25: 2010080Heat Loss (W)60402000 20 40
Page 26 and 27: 22Average Condensing Heat Transfer
Page 28 and 29: 24x = 0.77160140∆ T = 5.6o Cx = 0
Page 30 and 31: 26to produce paper at a higher rate
Page 32 and 33: 28a steady-state market penetration
Page 34 and 35: 30• The condensing heat transfer
Page 36 and 37: 32[9] J. C. Y. Wang, L. J. Qiu, and
Page 38 and 39: 34more of the available energy from
Page 40 and 41: 36Market Penetration, Energy Saving
Page 42 and 43: 38Market Penetration, Energy Saving

final report on the multiport dryer - Argonne National Laboratory

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?