Convection infrared drying

Dry heat is used to sterihze and depyrogenate components and drug products. The definition of dry heat sterilization is 170 °C for at least 2 hours and a depyrogenation cycle at 250 °C for more than 30 minutes. Typical equipment includes tunnel sterilizers (force convection, infrared, fiame) and microwave sterilizers. An important aspect is the need to ensure air supply is filtered through HEPA filters. Biological indicators such as Bacillus subtilis can be used to gauge the performance of sterilization. 

Following the application of paint, the item is passed through a drying or curing oven. The methods employed include convection, infrared or ultraviolet heating or combinations thereof. The particular methods depend on the types of paints being used, economics, and production requirements. Once dried, the items are sent for inspection and final packaging or assembly. 

It is clear that the MAPE, MAD, MSD values of this model were changed between 0.34-4.8, 0.22-1.63 and 0.08-33.22 respectively. As it can be seen for pine samples the convection method has a better fitness to the model and for spruce infrared drying model fitted the experimental data properly. 

Jaturonglumlert, S., Kiatsiriroat, T, 2010. Heat and mass transfer in combined convective and far-infrared drying of fruit leather. /. Food Eng. 100(2) 254-260. 

The two principal methods of dry-heat sterilization are infrared and convection hot air. Infrared rays will sterilize only surfaces. Sterilization of interior portions must rely on conduction. Convection hot-air sterilizers are normally heated electrically and are of two types gravity or mechanical. In gravity convection units, a fan is used to promote uniformity of heat distribution throughout the chamber. 

Drying may be carried out by direct gas heating, infrared, electric elements with forced air convection, hot air or live steam. 

Water on the plate surface is removed with the sponge rolls for removal of water, and the surface is dried with 90-100°C convectional air, and then further dried with 90-100°C far-infrared heater. 

The coated foil is then processed to the next step, the drying compartment. The drying compartment essentially consists of a convection heater with two small slits for the traversing of the foil. The surface temperature of the foil is measured by an infrared detector. Temperature control is crudal in this process step, as the aqueous slurry must not be allowed to boil, which would deteriorate the coat evenness. During drying, the coat thickness shrinks (depending on the water content of the... 

Another area of research that could be profitably explored is the use of remote sensing instruments to measure surface temperatures of textile assemblies. Infrared thermovision cameras have been used to visualize temperature distributions over clothed and nude persons in order to study the transport of microorganisms by convective heat flow (112). A variety of less expensive radiometers and radiation pyrometers that are used to measure and automatically control the temperature of textiles during drying and texturing (113, llU, 115) could also assess the thermal behavior of apparel and clothing assemblies and thus elucidate their contribution to thermal comfort indoors. 

All wet coated components must be dried before stoving. This is earned out with infrared radiation or in air convection driers. 

Recent sterilizer developments have led to the use of dry heat sterilizing tunnels where heat transfer is achieved by infrared irradiation or by forced convection in filtered laminar airflow tunnels. Items to be sterilized are placed on a conveyer belt and pass through a high temperature zone (250-300+ °C) over a period of several minutes. 

Stenters (Tenters) and Textile Dryers These are the basic type of dryer used for sheets or webs in the textile industry. The sheet is held by its edges by clips (clip stenter) or pins (pin stenter), which not only suspend the sheet but also keep it taut and regulate its width—a vit consideration in textile drying. Drying is by convection hot air is introduced from one or both sides, passes over the surface of the sheet, and permeates through it. Infrared panels may also be used to supply additional heat. A schematic diagram of the unit is shown in Fig. 12-88. A typical unit is 1.4 m wide and handles 2 to 4 t/h of material. 

The statistical collection and representation of the weather conditions for a specified area during a specified time interval, usually decades, together with a description of the state of the external system or boundary conditions. The properties that characterize the climate are thermal (temperatures of the surface air, water, land, and ice), kinetic (wind and ocean currents, together with associated vertical motions and the motions of air masses, aqueous humidity, cloudiness and cloud water content, groundwater, lake lands, and water content of snow on land and sea ice), nd static (pressure and density of the atmosphere and ocean, composition of the dry ir, salinity of the oceans, and the geometric boundaries and physical constants of the system). These properties are interconnected by the various physical processes such as precipitation, evaporation, infrared radiation, convection, advection, and turbulence, climate change... 

Allanic, N., P. Salagnac, and P. Glouannec, 2009a. Optimal constrained control of an infrared-convective drying of a polymer aqueous solution. Chemical Engineering Research and Design, 87(7), 908-914. 

Dostie, M., 1992. Optimization of a drying process using infrared radio frequency and convection heating. In Drying 92f A.S. Muiumdar (Ed.). Elsevier, Amsterdam, the Netherlands, 679pp. 

Dostie, M., J.-N. Seguin, D. Maure, Q.-A. Ton-That, and R. Chatigny, 1989. Preliminary measurements on the drying of thick porous materials hy comhination of intermittent infrared and continuous convection heating. In Drying 89, A.S. Mujumdar and M.A. Roques (Eds.), Hemisphere, New York. 

Fernando, W.J.N., H.-C. Low, and A.L. Ahmad, 2011. The effect of infrared on diffusion coefficients and activation energies in convective drying A case study for hanana, cassava and pumpkia Journal of Applied Sciences, 11(21), 3635-3639. 

Kowalski, S.J. and K. Rajewska, 2009. Convective drying enhanced with microwave and infrared radiation. Drying Technology, 27(7), 878-887. 

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