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Impinging air jets can be used to dewater, heat, and dry the web of tissue paper. High velocities of the air jets degrade the paper, and appropriate adjustments to the jet velocity and the distance of the nozzle from the surface of the wet web are crucial to obtain the highest quality product. This work investigated the correlation between the velocity of the air jet and the strength of paper subjected to the impingement method. Papers with an initial moisture content of 20% and various pulp mixes were tested, and the physical properties of papers were explored. After impinging an air jet, different tensile strength limits were obtained in the machine and cross directions. The paper had lower apparent density and higher roughness compared to classical pressing. The dependence of tensile strength and roughness on the fibers composition also was determined. Increasing the amount of eucalyptus fibers in impingement dewatered paper resulted in a decrease in its tensile strength and roughness. The value of elongation before breaking was the highest for softwood papers after the impingement method. The maximum velocity of an air jet that can be used to dewater or dry paper without the risk of damage to the papers was determined.

Impinging air jets can be used to dewater, heat, and dry the web of tissue paper. High velocities of the air jets degrade the paper, and appropriate adjustments to the jet velocity and the distance of the nozzle from the surface of the wet web are crucial to obtain the highest quality product. This work investigated the correlation between the velocity of the air jet and the strength of paper subjected to the impingement method. Papers with an initial moisture content of 20% and various pulp mixes were tested, and the physical properties of papers were explored. After impinging an air jet, different tensile strength limits were obtained in the machine and cross directions. The paper had lower apparent density and higher roughness compared to classical pressing. The dependence of tensile strength and roughness on the fibers composition also was determined. Increasing the amount of eucalyptus fibers in impingement dewatered paper resulted in a decrease in its tensile strength and roughness. The value of elongation before breaking was the highest for softwood papers after the impingement method. The maximum velocity of an air jet that can be used to dewater or dry paper without the risk of damage to the papers was determined. [ABSTRACT FROM AUTHOR]

The most important parameters to affecting tempering quality of glass are heating and suddenly cooling times. Heating time is affected by as parameters chemical composition, mass of the glass, average surface temperature, oven power. Suddenly cooling time affected by surface temperature in front of the cooling unit, surface temperature of the end of the cooling, the cooling unit configuration (nozzle-to-plate distance the nozzle diameter ratio H/D, the distance the nozzle-to-nozzle diameter ratio S/D, nozzle arrangement) and Reynolds number. In this study, for flat glass of 4 mm thick, it is studied suddenly cooling using the square and triangle staggering nozzle systems (S/D=2) in the glass tempering process, exchange of particle numbers depend on average Nusselt number at the end of tempering process. This study is done on the Re= Re=15000, 17500, 20000, 22500 and 25000 values and H/D=2, 4, 6, 8 and 10 rations. End of this study, average Nusselt number are exchange to particles numbers as direct proportion. Optimum cooling configurations of S/D=2 rations are obtained at the triangular array, Re=15000 value and 2≤H/D≤4 rations. [ABSTRACT FROM AUTHOR]

Impinging air jets due to their high heat and mass transfer capacity are widely used for heating, cooling and drying applications in nowadays industry. This study aims to investigate auto glass tempering project. Heat transfer characteristics of heated glass plates during their cooling with mutually placed circular air jets have been experimentally investigated. 4 mm thick glass samples were used in the experiments. Cooling process has been performed with 16 mutually placed nozzles of 8 mm in diameter and 80 mm in length in staggered arrangement. Nozzles were made of seamless aluminum pipes. Experiments have been conducted for dimensionless jet to plate distances (H/D) between 1 and 10, and S/D ratios which represents dimensionless distance between nozzle axis, for 2≤S/D≤10. Reynolds number has been fixed at 30000 for all experiments. According to the results the highest average Nusselt number (Num) has been achieved for S/D=2 and H/D=4 with a value 123.3 and the lowest average Nusselt number was obtained for S/D= 10 and H/D= 10 with a value 58.6. [ABSTRACT FROM AUTHOR]