Combined convective and infrared drying of a capillary porous body

Journal Article · Fri Jan 01 00:00:00 EST 1993 · Drying Technology; (United States)

DOI:https://doi.org/10.1080/07373939308916889· OSTI ID:6047887

Parrouffe, J ^[1]

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1. McGill Univ., Montreal, Quebec (Canada)

Conventional convective drying processes being energy intensive and relatively slow, other techniques are being more intensively studied to minimize of offset these limitations. Among these, the use of I.R. (infrared) heating has significant advantages for industrial drying applications: direct transfer of heat to the product; low thermal inertia of the I.R. heat source; high heat flux intensity (up to 60 kW/m[sup 2]); choice of the emitter wavelength to match the product absorption characteristics; accurate local application of the heat flux only where needed; heating homogeneity due to radiation penetration (small thickness); and ease of combination with other heating modes (convection, conduction). Despite such advantages, the design of the combined convective-I.R. drying oven still relies largely on experiments very often obtained with free convection-I.R. heating (no forced flow present) or with a full scale oven. Additionally, no drying models have been tested over the wide range of drying conditions encountered in the combined process. Thus, the objectives of this study were the following: to build a reliable experimental facility to study the high temperature combined convective-I.R. drying process; to evaluate the effect of I.R. heating on the convective heat and mass transfer coefficients; to determine the influence of combined convective and I.R. drying parameters on the critical moisture content of a model material (soda lime glass beads; 90-105 [mu]m diameter range); and to test the applicability of a drying front model for the case of convective as well as combined convective-I.R. drying of a capillary porous medium.

• OSTI ID: 6047887
• Journal Information: Drying Technology; (United States), Vol. 11:5; ISSN 0737-3937
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
DRYERS
DESIGN
POROUS MATERIALS
DRYING
CAPILLARY FLOW
CONVECTION
GLASS
HEAT FLUX
HEAT TRANSFER
HYBRID SYSTEMS
INFRARED RADIATION
MASS TRANSFER
MATHEMATICAL MODELS
MOISTURE
PARTICLE SIZE
SORPTIVE PROPERTIES
TECHNOLOGY ASSESSMENT
TEST FACILITIES
ELECTROMAGNETIC RADIATION
ENERGY TRANSFER
FLUID FLOW
MATERIALS
RADIATIONS
SIZE
SURFACE PROPERTIES
320303* - Energy Conservation
Consumption
& Utilization- Industrial & Agricultural Processes- Equipment & Processes