scholarly journals AIR VELOCITY PROFILES IN AIR BLAST FREEZERS FILLED WITH BOXES OF FRUIT PULP MODELS

2004 ◽  
Vol 3 (2) ◽  
Author(s):  
J.V. Resende ◽  
V. Silveira Jr.
Keyword(s):  
Flow Rate ◽  
Air Flow ◽  
Relative Difference ◽  
Freezing Process ◽  
Fruit Pulp ◽  
Air Flow Rate ◽  
Air Velocity ◽  
Operation Conditions ◽  
Air Stream ◽  
Pass Through

The changes in the air velocities caused by the resistance for the air flow due to fruit pulp model packaged (100 grams) and conditioned in multi layers boxes during freezing process were evaluated and air flow rate were estimated using a method of treatment of the experimental data. The air velocities were measured before the air pass through the pillage of multi layer boxes in the air stream. For the measurements processing was used a non linear regression routine. Air flow rate measured by the present method resulted of the numerical integration of air velocities adjusted profile. Results presented a relative difference 10 % higher than the standard average procedure, which consists in averaging the air velocity measurements performed at each point of the section. In the same fan operation conditions, the results shown for the 7 layers arrays of product in the boxes which the air velocity was 62% lower than the 3 layers arrays and 50.9 % lower than the 5 layers arrays of product. These results were proportional to the bulk area for the air flow.

scholarly journals AIR VELOCITY PROFILES IN AIR BLAST FREEZERS FILLED WITH BOXES OF FRUIT PULP MODELS

2004 ◽  
Vol 3 (2) ◽  
pp. 127
Author(s):  
J.V. Resende ◽  
V. Silveira Jr.
Keyword(s):  
Flow Rate ◽  
Air Flow ◽  
Freezing Process ◽  
Fruit Pulp ◽  
Air Flow Rate ◽  
Velocity Measurements ◽  
Air Velocity ◽  
Operation Conditions ◽  
Air Stream ◽  
Pass Through

The changes in the air velocities caused by the resistance for the air flow due to fruit pulp model packaged (100 grams) and conditioned in multi layers boxes during freezing process were evaluated and air flow rate were estimated using a method of treatment of the experimental data. The air velocities were measured before the air pass through the pillage of multi layer boxes in the air stream. For the measurements processing was used a non linear regression routine. Air flow rate measured by the present method resulted of the numerical integration of air velocities adjusted profile. Results presented a relative difference 10 % higher than the standard average procedure, which consists in averaging the air velocity measurements performed at each point of the section. In the same fan operation conditions, the results shown for the 7 layers arrays of product in the boxes which the air velocity was 62% lower than the 3 layers arrays and 50.9 % lower than the 5 layers arrays of product. These results were proportional to the bulk area for the air flow.

scholarly journals Automobile Radiator’s Engineering and Analysation

2020 ◽  
Vol 9 (5) ◽  
pp. 554-558
Keyword(s):  
Flow Rate ◽  
Heat Dissipation ◽  
Cooling System ◽  
Volume Flow Rate ◽  
Air Flow ◽  
Temperature Drop ◽  
Inlet Temperature ◽  
Air Flow Rate ◽  
Air Velocity ◽  
Cooling Fan

The shape of a radiator cover is crucial either in determining the pattern of air flow or in increasing the same through the radiator core thereby increasing the thermal efficiency, thus making it a necessity to understand it. Moreover the parts circumjacent to the core namely the upper tank, lower tank, cooling fan, fins, tubes, etc promote the air flow rate. Also it is to note that the air flow rate of discharge gases from radiator core is one of the prime factors in determining the automobile cooling system. Initially factors such as temperature, pressure, air flow rate that affect the performance are obtained in order to derive out the entities of operation. One of the observations that can be made through this paper is that as the volume of the coolant increases, the rate of heat dissipation increases, also parameters like inlet temperature and volume flow rate of coolant, air velocity, temperature drop and drop in pressure of coolant are factors that contribute in radiator performance evidently.

Particles Capturing and Correlation with Head Loss in a Pilot-Scale Biological Aerated Filter

2013 ◽  
Vol 409-410 ◽  
pp. 279-286
Author(s):  
Ting Li ◽  
Wen Yi Dong ◽  
Hong Jie Wang ◽  
Jin Nan Lin ◽  
Feng Ouyang ◽  
...  
Keyword(s):  
Flow Rate ◽  
Air Flow ◽  
Pilot Scale ◽  
Head Loss ◽  
Biological Aerated Filter ◽  
Air Flow Rate ◽  
Air Velocity ◽  
Lower Velocity ◽  
Aerated Filter ◽  
Filter Bed

Experimental observations of particle capturing through the biological aerated filter bed indicated that air flow rate plays an important role in head loss development by influencing the suspended solids distribution along the depth of the bed as well as the morphology of the deposits. The active height for the SS removal prolonged with the increasing of the air velocity based on the mechanism of first-order kinetics. With the increasing of the superficial air velocity, the effluent SS concentration and the time need to reach the stead-states after backwash both increased. The value of the SS spike in the effluent after backwash at superficial air velocity of 27 m/hr was nearly twice as much as that of 5.4m/hr. Distribution of the deposits at higher air velocity was more uniform. Deposits at lower velocity with air flow rate produced higher head loss gradient. The headloss increased with the increasing of deposits and the increase rate was faster when the deposits exceeded higher value.

scholarly journals Adsorbability Enhancement of Macroporous Resin by Dielectric Barrier Discharge Plasma Treatment to Phenol in Water

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Shoufeng Tang ◽  
Deling Yuan ◽  
Jun He
Keyword(s):  
Dielectric Barrier Discharge ◽  
Flow Rate ◽  
Barrier Discharge ◽  
Air Flow ◽  
Air Flow Rate ◽  
Macroporous Resin ◽  
Dbd Plasma ◽  
Dielectric Barrier ◽  
Operation Conditions ◽  
Kinetics And Isotherms

In order to enhance the adsorption efficiency and economize the use of macroporous resin, we have treated it with the dielectric barrier discharge (DBD) plasma to improve its adsorbing capacity for phenol. The effects of operation conditions, for instance, applied voltage, treated time, and air flow rate on resin, were investigated by adsorption kinetics and isotherms. Results showed that the adsorption data were in good agreement with the pseudo-second-order and Freundlich equation. Experimental results showed that the modified resin was 156.5 mg/g and 39.2% higher than the untreated sample, when the modified conditions were conducted for discharge voltage 20 kV, treatment time 45 min, and air flow rate 1.2 L/min. The resin was characterized by FTIR and nitrogen adsorption isotherms before and after the DBD processes. It was found that the reason for the enhancement of resin adsorbability was attributed to the DBD plasma changing the surface physical and chemical structure.

Generator of Fine Polydisperse Aerosol

2004 ◽  
Vol 69 (7) ◽  
pp. 1453-1463 ◽  
Author(s):  
Pavel Mikuška
Keyword(s):  
Flow Rate ◽  
Geometric Mean ◽  
Air Flow ◽  
Solute Concentration ◽  
Number Concentration ◽  
Solid Particles ◽  
Geometric Standard Deviation ◽  
Air Flow Rate ◽  
Term Operation ◽  
Air Stream

A simple and inexpensive laboratory generator of test aerosol is described. The generator is based on the principle of pneumatic atomization of a solution of a soluble compound by high-velocity air stream. After evaporation of solvent from produced droplets, solid particles are formed. The generator provides continuous unattended long-term operation with constant aerosol output. The performance characteristics of the generator were evaluated by spraying solutions of NaNO3 and (NH4)2SO4. The generator produced polydisperse aerosol in a fine region of particle sizes with a geometric mean diameter of 52.1 nm and a geometric standard deviation of 1.90 for the NaNO3 concentration in the sprayed solution 30 g/l. The total number concentration of the produced aerosol was 3.14 × 107 cm-3 at a nominal air flow rate 78 l/min. The number concentration of particles increased with increasing flow rate of solution, solute concentration and pressure of compressed air through the atomizer or with decreasing total air flow rate through the generator. The change in any of these variables can be used to adjust the particle number concentration. NaNO3 aerosol generation rate was 0.172 mg/min for the NaNO3 concentration in the sprayed solution 30 g/l.

An Intelligent Reference Governor for Primary Air Control System in a Circulating Fluidized Bed

2015 ◽  
Vol 719-720 ◽  
pp. 376-380
Author(s):  
Xu Sheng Zhuo ◽  
Tong Li ◽  
Fan Yang ◽  
Dan Dan Wang
Keyword(s):  
Fluidized Bed ◽  
Flow Rate ◽  
Circulating Fluidized Bed ◽  
Control Method ◽  
Air Flow ◽  
Feed Flow Rate ◽  
Air Flow Rate ◽  
Operation Conditions ◽  
Bed Temperature ◽  
Reference Governor

In combustion of a circulating fluidized bed, primary air plays a key role in keeping materials fluidized and regulating bed temperature. This report provides a design of reference governor for primary air fans to amend their control commands. That will improve the combustion efficiency via regulating primary air flow rate timely according to the changes of coal feed flow rate and bed temperature. To deal with the large inertia and slow response feature of primary air fans, a rule-based control method was used to design the reference governor. Based on the experiences of technical experts and operation data analysis, an expert rules system with wide coverage range was developed, which composed of the logical relationships between the coal feed flow rate, bed temperature and the primary air flow rate in various operation conditions. Test results show that designed reference governor can improve the control performance of primary air flow rate obviously.

Numerical Simulation of Air Flow in BiPV-Trombe Wall

2013 ◽  
Vol 860-863 ◽  
pp. 141-145 ◽  
Author(s):  
Xiao Wei Xu ◽  
Ya Xin Su
Keyword(s):  
Numerical Simulation ◽  
Reynolds Number ◽  
Flow Rate ◽  
Air Flow ◽  
Channel Height ◽  
Air Flow Rate ◽  
Air Velocity ◽  
Trombe Wall ◽  
Multivariable Regression ◽  
Cfd Method

A novel built-in photovoltaic Trombe wall (BiPV-TW) was proposed in this paper and the air flow in a BiPV-Trombe wall was numerically simulated by CFD method. The effect of channel height on flow patterns and air velocity was analyzed. The mass flow rate of air was calculated and a dimensionless expression to calculate the air flow rate in term of a Reynolds number was correlated according to a modified Rayleigh number and the aspect ratio, H/b, which took into account both of the channel sizes and solar radiation based on a multivariable regression analysis.

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