final report on the multiport dryer - Argonne National Laboratory

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2010080Heat Loss (W)60402000 20 40 60 80 100Temperature Difference (Fig. 7. Heat loss, based on single-phase heat transfer tests,as a function of temperature difference betweenwall and ambiento C)8 EXPERIMENTAL RESULTS AND DISCUSSIONTo investigate the heat transfer characteristics of a multiport cylinder dryer channel undertypical condensing conditions and to demonstrate the advantages of multiport cylinder dryersover conventional cylinder dryers, we performed a series of condensing heat transferexperiments in a specially designed multiport cylinder dryer heat transfer test apparatus. Theexperimental parameters are listed in Table 1.Condensation was experimentally investigated for steam flowing in a horizontalrectangular channel, 18.90 mm (0.75 in.) wide, 3.14 mm (0.125 in.) high, and 3 m (10 ft.) cooledlength. A series of condensing tests was performed over a range of mass flux of 20-49 kg/m 2 s(4.1 lb/ft 2 s-10.1 lb/ft 2 s), pressure of 170-620 kPa (25-90 psia), and quality of 0.1-0.8. We havefocused condensing heat transfer tests on the effects of mass flux, pressure, and quality on thecharacteristics of condensing heat transfer. Also we have measured the two-phase pressuregradient as a function of mass flux, and wall temperature as a function of axial location. In eachtest, local values of the condensing heat transfer coefficient and quality were determined atmeasurement points along the test section.
21Table 1. Value/range of experimental parametersParameterTested rangeFlow channelRectangular channelFlow directionHorizontalHydraulic diameter, mm 10.8Maximum condensing length, m 2.87Steam temperature, °C 115-160Quality, % 10-80Heat flux, kW m 2 11.6-201Mass flux, kg m 2 s 20-50Pressure, kPa 170-620Reynolds number of liquid 910-2970Prandtl number of liquid 1.09-1.52Uncertainties for experimental results were determined by using the method of sequentialperturbation, as outlined by Moffat [17] for single-sample data. Uncertainties in each of theindependent variables used to calculate the heat transfer coefficient were estimated on the basisof calibration and examination of system/sensor interaction errors. The uncertainties are
Page 1: ARGONNE NATIONAL LABORATORY9700 Sou
Page 4 and 5: Figures1 Resistances to heat transf
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 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

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