A PRACTICAL METHOD FOR PREDICTING THE DEMISTING PERFORMANCE OF HOT AIR JETS

1974 ◽  
Author(s):  
P.W. Fitt ◽  
A.O. Adewusi
Keyword(s):  
Practical Method ◽  
Air Jets ◽  
Hot Air

Simulation of Heat Transfer From Hot-Air Jets Impinging a Three-Dimensional Concave Surface

2009 ◽  
Vol 46 (2) ◽  
pp. 721-726 ◽  
Author(s):  
Mathieu Fregeau ◽  
Mohammad Gabr ◽  
Ion Paraschivoiu ◽  
Farooq Saeed
Keyword(s):  
Heat Transfer ◽  
Three Dimensional ◽  
Concave Surface ◽  
Air Jets ◽  
Hot Air

Aerodynamic Characteristics of Pressure-Pad Air Bars

1999 ◽  
Vol 67 (1) ◽  
pp. 177-182 ◽  
Author(s):  
Y. B. Chang ◽  
P. M. Moretti
Keyword(s):  
Ground Effect ◽  
Aerodynamic Characteristics ◽  
Aerodynamic Forces ◽  
Plastic Films ◽  
Air Jets ◽  
Hot Air ◽  
Air Jet ◽  
Air Flotation ◽  
Main Components ◽  
The Web

Air-flotation ovens are widely used for noncontact support and drying of coated paper and plastic films (generically called webs). The main components in typical air-flotation ovens are air bars which have slot nozzles or holes through which hot air jets are ejected. Problems in air-flotation drying techniques include sideward motion of the web, web flutter, and contact between the web and air bars. The key to analyzing these problems is to determine the aerodynamic forces on the web. This paper discusses the aerodynamic forces generated by pressure-pad-type air bars, each of which has two slot nozzles. Ground-effect theories, which were originally developed for the design of hovercraft, are re-examined. The theories are compared with the measured values of the aerodynamic forces for typical air bars. It is shown that ground effect theories can be applied to pressure-pad-type air bars if we properly define the equivalent values of the ground effect variables, which include thickness of the air jet, flotation height, ejection angle of the air jet, and the effective total pressure of the air jet. [S0021-8936(00)02801-4]

ANALYSIS OF EVAPORATIVE DRYING OF THIN INK FILMS USING HIGH-VELOCITY HOT-AIR IMPINGING JETS: A COMPREHENSIVE REVIEW

2020 ◽  
Vol 27 (09) ◽  
pp. 1950210
Author(s):  
BURAK TURKAN ◽  
AKIN BURAK ETEMOGLU ◽  
MUHIDDIN CAN
Keyword(s):  
Mass Transfer ◽  
Operating Cost ◽  
Impinging Jets ◽  
Chemical Processes ◽  
Comprehensive Review ◽  
Food Industries ◽  
Air Jets ◽  
Hot Air ◽  
Comprehensive Literature Review ◽  
Supply Information

Hot impinging air jets are usually used to increase heat and mass transfer. The dehydration of materials is a procedure of common significance in the chemical processes, forensic science and food industries; in the fabrication of paper, plastics and textiles as well. Effective drying of thin ink films is becoming progressively significant in the quickly development printing, packaging and coating industries. In order to minimize capital and operating cost, variables need to be optimized. For both researchers and commercial dryers, an optimization of the nozzles under striking air jets is offered for ink drying. To supply information to industrial users, a comprehensive literature review was presented to the research. An outline of the previous work of impinging air jets is also given.

scholarly journals Numerical modelling of the interaction between water sprays and hot air jets - Part I: Gas phase Large Eddy Simulations

2018 ◽  
Vol 95 ◽  
pp. 77-86 ◽  
Author(s):  
Tarek Beji ◽  
Georgios Maragkos ◽  
Setareh Ebrahimzadeh ◽  
Bart Merci
Keyword(s):  
Numerical Modelling ◽  
Gas Phase ◽  
Large Eddy Simulations ◽  
Air Jets ◽  
Hot Air ◽  
Large Eddy ◽  
Water Sprays

Drying of Rubber Sheet Using Impingement of Multiple Hot Air Jets

2013 ◽  
Vol 844 ◽  
pp. 502-506 ◽  
Author(s):  
Chayut Nuntadusit ◽  
Makatar Waehahyee
Keyword(s):  
Heat Transfer ◽  
Moisture Content ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Drying Rate ◽  
Rubber Sheet ◽  
Air Jets ◽  
Hot Air ◽  
Rubber Surface ◽  
Jet Velocity

In the process for producing ribbed smoked rubber sheet, the rubber sheet drying is the most time and energy consumption process. This research study the possibility in develop new drying system using array of hot air jets impinging directly on rubber sheet in order to reduce time for drying rubber in smoked room and increase productivity of rubber sheets. In the study, the array of jets from jet plate with drilled jet holes in staggered arrangement impinged on the both side of rubber sheet. The effects of jet velocity (Vj=10, 16, 23 m/s), jet temperature (Tj=50, 60, 70°C) and the distance from jet outlet to rubber surface (L=4D, 6D, 8D which D is diameter of jet hole) on drying rate were investigated by measuring weight of rubber sheet change with time. The heat transfer rate on impinged surface was also measured by attaching a heat flux sensor on impinged wall. The results showed that the convective heat transfer coefficient increased when the jet velocity was increased and when the distance from jet was decreased particularly in jet directly impinged region. It was found that the enhancement in heat transfer rate from jets cannot increase the rubber drying rate for all cases because the drying rate depend on rubber property. The process of rubber sheet drying can be divided in 2 periods; in the first drying period, the drying rate decreases with decreased moisture content. The drying rate depended on the initial moisture content and the condition of external effect such as jet velocity, jet temperature and distance from jet outlet to rubber surface. In second drying period, the moisture content is below 20% dry basis. In this period, the drying rate is almost constant near zero. It was also found that the drying for case of L=6D was higher than case of L=4D and 8D. The optimum condition for rubber sheet drying without defects on rubber property after drying was L=6D and Tj=70°C.

Influence of Blanching Pretreatment on the Drying Characteristics of Cherry Tomato and Mathematical Modeling

2015 ◽  
Vol 11 (2) ◽  
pp. 265-274 ◽  
Author(s):  
Li-Shuang Cheng ◽  
Sheng Fang ◽  
Mao-Lin Ruan
Keyword(s):  
Color Change ◽  
Practical Method ◽  
Moisture Diffusivity ◽  
Effect Of Temperature ◽  
Diffusivity Coefficient ◽  
Chi Square ◽  
Hot Air ◽  
Mean Square Errors ◽  
Cherry Tomatoes

Abstract The hot air drying with blanching pretreatment may provide a practical method for the production of dried cherry tomatoes. The influences of drying temperature (50°C, 60°C, 70°C and 80°C) and blanching on the drying kinetics of cherry tomatoes were studied. Nine mathematical models were evaluated and the determination of coefficient (R2), chi-square (χ2) and root mean square errors (RMSE) were compared. The Logarithmic model gave best results with R2 of 0.9992 and 0.9995 for fresh and blanched cherry tomatoes, respectively. The values of effective moisture diffusivity coefficient Deff varied in the range of 1.7281 × 10−9 to 4.6306 × 10−9 m2 s−1 for the fresh cherry tomatoes, while 2.1034 × 10−9 to 6.6487 × 10−9 m2 s−1 for the blanched samples. The values of activation energy were 31.99 and 36.21 kJ mol−1 for the raw and blanched cherry tomatoes, respectively. Furthermore, the effect of temperature and blanching on color change of cherry tomatoes was measured.

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