scholarly journals Study of Master Controller Structure for Multiple Air Compressor System

2021 ◽  
Vol 7 (1) ◽  
pp. 68-72
Author(s):  
Roman Kokoshko ◽  
◽  
Oleksandr Kril ◽  
Bohdan Kril
Keyword(s):  
Flow Rate ◽  
Frequency Converter ◽  
Air Flow ◽  
Compressed Air ◽  
Rate Variation ◽  
Air Flow Rate ◽  
Informative Signal ◽  
Air Compressor ◽  
Operation Speed ◽  
Master Controller

Compressed air is an important medium for energy transfer in industrial processes. It drives various actuators, which create a large force for significant movements and a high operation speed. Thereat, these mechanisms are quite small, and the design is simple and reliable. They are applicable in food and pharmaceutical technologies. Compressed air systems belong to the largest energy consumers at such enterprises. They consist of several compressors, and the drive of one of them is powered by a frequency converter in order to save electrical energy. This is called a multiple air compressor system, and its operation is controlled by a separate controller – master controller. The paper discusses the results of developing the master controller design and its operation algorithm. As an additional informative signal in the developed design of the master controller, air flow rate measurements are used; additionally, the speed of the air flow rate variation is analysed.

scholarly journals The influence of mixing solid particles on the kinetic of benzoic acid dissociation during the pneumatic mixing of solution

2018 ◽  
Vol 28 (7) ◽  
pp. 92-96
Author(s):  
O. M. Danyliuk ◽  
V. M. Atamaniuk ◽  
Z. Ya. Hnativ
Keyword(s):  
Benzoic Acid ◽  
Flow Rate ◽  
Air Flow ◽  
Solid Particles ◽  
Compressed Air ◽  
Acid Dissociation ◽  
Dissolution Process ◽  
Experimental Investigations ◽  
Air Flow Rate ◽  
Acid Dissolution

The current research characterizes the regularities of the process of polydisperse mixture of benzoic acid dissociation during the pneumatic mixing of solution. The advantages of using compressed air for dissolution are presented. The authors also describe the method of conducting experimental investigations. The research is focused on the using of solid and chemically inert mixing additives, which supply into the process at the beginning. The authors have estimated the influence of these solid particles of different forms, which were produced by chemically inert to benzoic acid materials (glass, plastic, rubber, polyacetal), and in the process pneumatic mixing, and, correspondingly, on the kinetic of benzoic acid dissolution in water. We have also discovered that optimal for mixing of benzoic acid solution particles have spherical shape, which are made of plastic, and have diameter 7 mm and specific density 1280 kg/m3. Experimental investigations enabled the determination of the fact that introduction of mixing additives in the quantity of 2 % from the volume of solution is critical and sufficient for avoiding of passing out of the solid phase in the foam layer and reduce the dissolution time to the necessary concentration. We have also investigated the influence of mixing additives on the dissolution duration and energy expenses. The maximum permissible compressed air flow rate for prevention of solution transition into foam state was determined. Furthermore, the impact of compressed air flow rate variation on the kinetic of dissolution process was investigated. The analysis of graphic dependency reveals that adding of mixing additives and increasing of compressed air consumption reduces the average duration of dissolution process. From the other side, such consumption of compressed air is critical in conditions of current research, as its further increasing over 5.6 m3/hour leads to transformation of 80 % of solution into foam. Finally the kinetic of benzoic acid dissolution to the concentration 1.2 kg/m3 with using of mixing additives in the conditions of incomplete solution saturation was experimentally determined and analysed.

Effect of process conditions and carrier concentration for improving drying yield and other quality attributes of spray dried black mulberry (Morus nigra) juice

2012 ◽  
Vol 8 (1) ◽  
Author(s):  
Mahboubeh Fazaeli ◽  
Zahra Emam-Djomeh ◽  
Ahmad Kalbasi-Ashtari ◽  
Mahmoud Omid
Keyword(s):  
Spray Drying ◽  
Flow Rate ◽  
Air Flow ◽  
Compressed Air ◽  
Anthocyanin Content ◽  
Air Flow Rate ◽  
Total Anthocyanin ◽  
Independent Variables ◽  
Morus Nigra ◽  
Total Anthocyanin Content

The objective of this work was to study the influence of spray drying conditions on the physicochemical properties of black mulberry (Morus nigra) powder. A lab-scale spray dryer was employed for the spray drying process and maltodextrin DE=9was used as carrier agent.Response surface methodology (RSM) was performed to examine the effects of independent variables on the drying yield, color change, and total anthocyanin content and to determine the optimum processing conditions. Independent variables were: inlet air temperature (110 ºC, 130 ºC, and 150 ºC), compressed air flow rate (400, 600, and 800 l/h), and maltodextrin concentration (8%, 12%, and 16%). For each response, second order polynomial models were developed using multiple linear regression analysis. Analysis of variance was performed to check the adequacy and accuracy of the fitted models. The optimal conditions for drying yield and total anthocyanin content correspond to: temperature= 130 ºC, maltodextrin concentration= 8%, and compressed air flow rate= 800 L/h; these parameters led to the total anthocyanin content, process yield and browning index values of 5.85 (mg/100mL), 75%, 58.57% respectively.

Influence of Operating Parameters on Physicochemical Properties of Fruit Juice Powders Produced by Spray Drying

2014 ◽  
Vol 941-944 ◽  
pp. 1196-1200
Author(s):  
Li Li Zhang ◽  
Chuan Chuan Ma
Keyword(s):  
Moisture Content ◽  
Physicochemical Properties ◽  
Bulk Density ◽  
Air Temperature ◽  
Flow Rate ◽  
Fruit Juice ◽  
Air Flow ◽  
Compressed Air ◽  
Operating Parameters ◽  
Air Flow Rate

This paper investigated the influence of operating parameters such as inlet air temperature, compressed air flow rate, concentration of carrier agent and type of carrier on the physicochemical properties of fruit juice powders produced by spray drying.The results indicated that increasing inlet air temperature resulted in the larger size particles with smoothly spherical appearance, and to lower bulk density and moisture content. The bulk density of powders also decreased with increasing carrier agent concentration, decreasing compressed air flow rate. The higher feed flow rate negatively affected process yield and positively influenced moisture content, and occurring the wall deposition easily. Additionally, the anthocyanin retention mainly depends on the inlet air temperature and type of carrier. Moreover, the novel methods and ideas to this problem in the next studies were presented.

Experimental Study of a Water Desalination System Based on Humidification-Dehumidification Process Using a Heat Pump

2015 ◽  
Author(s):  
Anwar H. Hegazy ◽  
Mohamed A. Teamah ◽  
Ahmed A. Hanafy ◽  
Wael M. El-Maghlany
Keyword(s):  
Production Rate ◽  
Heat Pump ◽  
Flow Rate ◽  
Air Flow ◽  
Operating Conditions ◽  
Water Desalination ◽  
Coefficient Of Performance ◽  
Electric Heater ◽  
Rate Variation ◽  
Air Flow Rate

In this paper an experimental investigation on a lab scale HDH water desalination unit using a Heat pump was presented. From the thermodynamic view, it was found that the electric heater has a coefficient of performance equal unity, while the heat pump has a coefficient of performance greater than one; in other words the dissipated heat has a high scale. In addition, the refrigeration effect could be used as a secondary benefit. The proposed system utilizes the heat rejected and the cooling effect of the mechanically driven vapor compression heat pump for fresh water production. A test rig consisting of a fan, condenser duct, water spray humidifier and evaporator duct was constructed to study the performance under different operating conditions. The effect of air flow rate variation and water spraying direction (cross, counter or parallel) in the humidification process were studied. Experiments were carried out under variable inlet air conditions. Air flow rate was varied from 0.076 m3/s to 0.4054 m3/s. Results showed that cross water spraying humidification tests yielded the highest production rate. The unit’s maximum production rate was found to be 2.8 Liters/hour at a power 1.4091 kW.

scholarly journals Model of thermal buoyancy in cavity-ventilated roof constructions

2021 ◽  
pp. 174425912098418
Author(s):  
Toivo Säwén ◽  
Martina Stockhaus ◽  
Carl-Eric Hagentoft ◽  
Nora Schjøth Bunkholt ◽  
Paula Wahlgren
Keyword(s):  
Analytical Model ◽  
Flow Rate ◽  
Numerical Study ◽  
Air Flow ◽  
Wind Pressure ◽  
Air Flow Rate ◽  
Test Set ◽  
Air Cavity ◽  
Thermal Buoyancy ◽  
The Impact

Timber roof constructions are commonly ventilated through an air cavity beneath the roof sheathing in order to remove heat and moisture from the construction. The driving forces for this ventilation are wind pressure and thermal buoyancy. The wind driven ventilation has been studied extensively, while models for predicting buoyant flow are less developed. In the present study, a novel analytical model is presented to predict the air flow caused by thermal buoyancy in a ventilated roof construction. The model provides means to calculate the cavity Rayleigh number for the roof construction, which is then correlated with the air flow rate. The model predictions are compared to the results of an experimental and a numerical study examining the effect of different cavity designs and inclinations on the air flow rate in a ventilated roof subjected to varying heat loads. Over 80 different test set-ups, the analytical model was found to replicate both experimental and numerical results within an acceptable margin. The effect of an increased total roof height, air cavity height and solar heat load for a given construction is an increased air flow rate through the air cavity. On average, the analytical model predicts a 3% higher air flow rate than found in the numerical study, and a 20% lower air flow rate than found in the experimental study, for comparable test set-ups. The model provided can be used to predict the air flow rate in cavities of varying design, and to quantify the impact of suggested roof design changes. The result can be used as a basis for estimating the moisture safety of a roof construction.

scholarly journals Modeling and optimization of radish root extract drying as peroxidase source using spouted bed dryer

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shahrbanoo Hamedi ◽  
M. Mehdi Afsahi ◽  
Ali Riahi-Madvar ◽  
Ali Mohebbi
Keyword(s):  
Kinetic Parameters ◽  
Flow Rate ◽  
Air Flow ◽  
Cost Effective ◽  
Industrial Applications ◽  
Interactive Effects ◽  
Root Extract ◽  
Air Flow Rate ◽  
Spouted Bed ◽  
Radish Root

AbstractThe main advantages of the dried enzymes are the lower cost of storage and longer time of preservation for industrial applications. In this study, the spouted bed dryer was utilized for drying the garden radish (Raphanus sativus L.) root extract as a cost-effective source of the peroxidase enzyme. The response surface methodology (RSM) was used to evaluate the individual and interactive effects of main parameters (the inlet air temperature (T) and the ratio of air flow rate to the minimum spouting air flow rate (Q)) on the residual enzyme activity (REA). The maximum REA of 38.7% was obtained at T = 50 °C and Q = 1.4. To investigate the drying effect on the catalytic activity, the optimum reaction conditions (pH and temperature), as well as kinetic parameters, were investigated for the fresh and dried enzyme extracts (FEE and DEE). The obtained results showed that the optimum pH of DEE was decreased by 12.3% compared to FEE, while the optimum temperature of DEE compared to FEE increased by a factor of 85.7%. Moreover, kinetic parameters, thermal-stability, and shelf life of the enzyme were considerably improved after drying by the spouted bed. Overall, the results confirmed that a spouted bed reactor can be used as a promising method for drying heat-sensitive materials such as peroxidase enzyme.

Sign in / Sign up

Export Citation Format

Share Document