EFFECTS OF MOISTURE AND FINE MATERIAL ON STATIC PRESSURE DROPS IN A BED OF GRAIN SORGHUM AND ROUGH RICE

2001 ◽  
Vol 44 (2) ◽  
Author(s):  
D. S. Chung ◽  
R. G. Maghirang ◽  
Y. S. Kim ◽  
M. S. Kim
Keyword(s):  
Static Pressure ◽  
Grain Sorghum ◽  
Pressure Drops ◽  
Fine Material ◽  
Rough Rice

EVALUATION OF STATIC PRESSURE DROPS AND PM10 AND TSP EMISSIONS FOR MODIFIED 1D-3D CYCLONES

1999 ◽  
Vol 42 (6) ◽  
pp. 1541-1548 ◽  
Author(s):  
G. A. Holt ◽  
R. V. Baker ◽  
S. E. Hughs
Keyword(s):  
Static Pressure ◽  
Pressure Drops

Experimental and Computational Analyses of Pressure Differentials in Flexible Ducts With Different Bent Angles

2007 ◽  
Author(s):  
Ray R. Taghavi ◽  
Wonjin Jin ◽  
Mario A. Medina
Keyword(s):  
Pressure Drop ◽  
Static Pressure ◽  
Complex Geometry ◽  
Analysis Data ◽  
Secondary Flows ◽  
Low Flow ◽  
Pressure Drops ◽  
Pressure Distributions ◽  
Geometrical Effects ◽  
Cfd Analyses

A set of experimental analyses was conducted to determine static pressure drops inside non-metallic flexible, spiral wire helix core ducts, with different bent angles. In addition, Computational Fluid Dynamics (CFD) solutions were performed and verified by comparing them to the experimental data. The CFD computations were carried out to produce more systematic pressure drop information through these complex-geometry ducts. The experimental setup was constructed according to ASHRAE Standard 120-1999. Five different bent angles (0, 30, 45, 60, and 90 degrees) were tested at relatively low flow rates (11 to 89 CFM). Also, two different bent radii and duct lengths were tested to study flexible duct geometrical effects on static pressure drops. FLUENT 6.2, using RANS based two equations - RNG k-ε model, was used for the CFD analyses. The experimental and CFD results showed that larger bent angles produced larger static pressure drops in the flexible ducts. CFD analysis data were found to be in relatively good agreement with the experimental results for all bent angle cases. However, the deviations became slightly larger at higher velocity regimes and at the longer test sections. Overall, static pressure drop for longer length cases were approximately 0.01in.H2O higher when compared to shorter cases because of the increase in resistance to the flow. Also, the CFD simulations captured more pronounced static pressure drops that were produced along the sharper turns. The stronger secondary flows, which resulted from higher and lower static pressure distributions in the outer and inner surfaces, respectively, contributed to these higher pressure drops.

Aerodynamic Torque Acting on a Butterfly Valve. Comparison and Choice of a Torque Coefficient

1999 ◽  
Vol 121 (4) ◽  
pp. 914-917 ◽  
Author(s):  
C. Solliec ◽  
F. Danbon
Keyword(s):  
Pressure Drop ◽  
Static Pressure ◽  
Fluid Dynamic ◽  
Dynamic Pressure ◽  
Low Cost ◽  
Normalization Method ◽  
Pressure Drops ◽  
Torque Coefficient ◽  
Aerodynamic Torque ◽  
Valve Pressure

Most technological devices use butterfly valves to check the flow rate and speed, through piping. Their main advantages are their low cost, their mechanical suitability for fast operation, and their small pressure drops when they are fully open. The fluid dynamic torque about the axis of large valves has to be considered as the actuator could be overstrained. This torque is generally defined using a nondimensional coefficient KT, in which the static pressure drop created by the valve is used for normalization. When the valve is closed downstream of an elbow, the valve pressure drop is not well defined. Thus, the classic normalization method gives many ambiguities. To avoid the use of the pressure drop, we define another torque coefficient CT in which the dynamic pressure of the flow is the normalization factor instead of the pressure drop. Advantages and drawbacks of each normalization method are described in the following.

Numerical Investigation for Inner Flow Fields and Structure Improvements of Medium Speed Mill

2013 ◽  
Vol 732-733 ◽  
pp. 481-486
Author(s):  
Xian Ran Zhu ◽  
Cheng Yong Liu ◽  
Liang Cheng
Keyword(s):  
Numerical Model ◽  
Pressure Drop ◽  
Numerical Investigation ◽  
Flow Rate ◽  
Static Pressure ◽  
Flow Fields ◽  
Field Conditions ◽  
Pressure Drops ◽  
Medium Speed ◽  
Commercial Code

The numerical model for ZGM95 medium speed mill is built and the inner flow fields are simulated by employing the commercial code of FLUENT. The results show that the distributions of the static pressure and the flow rate are not uniform for 36 nozzle rings due to the primary air entering the mill only from one side. Two modified structures are assumed to improve the mills performances and the corresponding models are simulated further. The flow fields are still not good enough and the pressure drop increases sharply in the mill when blocking several nozzle rings, and this structure is not recommended if the amount of pulverizer rejects is not extremely huge. The structure with double-inlet can improve the distribution of the flow fields effectively in the mill and few pressure drops of the mill increase. However, the feasibility of the double-inlet structure is also depends on the field conditions. The pressure drop will be less and the flow fields will be better when adopting the horizontal inlet duct instead of the inclined one.

scholarly journals Pitot Tube-Based Icing Detection: Effect of Ice Blocking on Pressure

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Xianglian Lv ◽  
Jie Guan ◽  
Shengkun Wang ◽  
Haiyang Zhang ◽  
Shijie Xue ◽  
...  
Keyword(s):  
Total Pressure ◽  
Static Pressure ◽  
Detection System ◽  
Low Cost ◽  
Pitot Tube ◽  
Detection Methods ◽  
Pressure Drops ◽  
Aerial Vehicle ◽  
Pressure Output ◽  
Detection Effect

This study aims at addressing a problem on icing detection for Unmanned Aerial Vehicle (UAV for short) because traditional icing detection methods are costly and bulky. Toward this end, a pitot-based icing detection method is proposed, and the effect of different types of icing blocking on pressure is firstly reported. An icing detection system based on the pitot tube is designed and fabricated. Icing wind tunnel results indicate that if the pitot tube is blocked by glaze ice, then the total pressure of the pitot tube decreases gradually and remains unchanged and less than static pressure. However, if the pitot tube is blocked by rime ice, then the total pressure drops to the same level as the static pressure. If the pitot tube is blocked by non-ice organic materials, then the total pressure suddenly drops to the same level as the static pressure and remains unchanged. Furthermore, if the pitot tube contacts the water droplets but does not freeze, the total pressure output value fluctuates slightly. The effect of icing on pressure is caused by differences in ice microstructure, temperature, and flow velocity. At the same time, the proposed method offers a facile and low-cost approach for UAV icing detection.

scholarly journals Flow Simulation and Model Analysis of Efficiency and Pressure Ratio Behaviors in GT4086 Turbocharger Compressor

Mechanika ◽  
2020 ◽  
Vol 26 (4) ◽  
pp. 293-300 ◽  
Author(s):  
Mohammad Omidi
Keyword(s):  
Pressure Drop ◽  
Global Minimum ◽  
Static Pressure ◽  
Mass Parameter ◽  
Pressure Ratio ◽  
Flow Simulation ◽  
Model Analysis ◽  
Global Maximum ◽  
Pressure Drops ◽  
Specific Speed

The present paper seeks to model and simulate the function of a centrifugal GT4082 compressor and evaluates the effects of losses in the impeller, volute, and diffuser. It is also examined the mass parameter effect on the efficiency drop at different speeds. The total and static pressure drops are also examined in the volute and diffuser. Based on the experiments, the efficiency drops in these parts modeled at different mass parameters and speeds discovered to be maximized in the volute and diffuser at a specific speed. A global minimum was observed in the overall pressure drop and a global maximum in the static pressure drop versus a mass parameter.

An experience of elaboration and implementation of systems of slag-forming mixtures mechanized feeding into CCM moulds

2020 ◽  
Vol 76 (10) ◽  
pp. 994-1003
Author(s):  
S. P. Eron’ko ◽  
M. Yu. Tkachev ◽  
E. V. Oshovskaya ◽  
B. I. Starodubtsev ◽  
S. V. Mechik
Keyword(s):  
Economic Effect ◽  
Three Dimensional ◽  
Movable Part ◽  
High Quality ◽  
Working Zone ◽  
Fine Material ◽  
Mixing Chamber ◽  
Field Samples ◽  
Technical Solutions ◽  
Feeding Systems

Effective application of slag-forming mixtures (SFM), being fed into continuous castingg machine (CCM) moulds, depends on their even distribution on the melt surface. Manual feeding of the SFM which is widely usedd does not provide this condition, resulting in the necessity to actualize the work to elaborate systems of SFM mechanized feedingg into moulds of various types CCM. A concept of the designing of a system of SFM feeding into CCM moulds presented with the ratte strictly correspondent to the casting speed and providing formation of an even layer of fine material of given thickness on the whoole surface of liquid steel. The proposed methods of designing of the SFM mechanized feeding systems based on three-dimensional computer simulation with the subsequent verification of the correctness of the adopted technical solutions on field samples. Informattion is presented on the design features of the adjusted facilities intended for continuous supply of finely granulated and powder mixtuures on metal mirror in moulds at the production of high-quality billets, blooms and slabs. Variants of mechanical and pneumo-mechaanical SFM supply elaborated. At the mechanical supply the fine material from the feeding hopper is moved at a adjusted distance bby a rigid horizontally located screw. At the pneumo-mechanical supply the metered doze of the granular mixture is delivered by a sshort vertical screw, the lower part of which is located in the mixing chamber attached from below to the hopper and equipped with ann ejector serving for pneumatic supply of the SFM in a stream of transporting gas. It was proposed to use flexible spiral screws in the ffuture facilities of mechanical SFM feeding. It will enable to eliminate the restrictions stipulated by the lack of free surface for locatiion of the facility in the working zone of the tundish, as well as to decrease significantly the mass of its movable part and to decreaase the necessary power of the carriage moving mechanism driver. The novelty of the proposed technical solutions is protected by thhree patents. The reduction of 10–15% in the consumption of slag-forming mixtures during the transition from manual to mechanizeed feeding confirmed. The resulting economic effect from the implementation of technical development enables to recoup the costs inncurred within 8–10 months.

Perancangan Pengkondisian Udara pada Ruangan Steril Rumah Sakit Mitra Medika dengan Standard Cleanroom Menggunakan Instalasi Ducting

2019 ◽  
Vol 2 (2) ◽  
Author(s):  
Fremmy Raymond Agustinus
Keyword(s):  
Air Conditioning ◽  
Static Pressure ◽  
Filter Medium ◽  
Positive Pressure ◽  
Design Tools ◽  
Microsoft Excel ◽  
Cooling Unit ◽  
X 24 ◽  
Air Passage ◽  
Booster Fan

Desain penyejuk udara juga dapat diterapkan di bidang kesehatan, dengan standar Cleanroom dapat diperoleh suhu, kelembaban, kenyamanan dan kebersihan yang dibutuhkan untuk ruang steril (ruang bedah). Perancangan pendingin udara dalam hal ini dilakukan dengan menentukan beban pendinginan yang diperlukan untuk ruang steril (ruang bedah), kemudian menentukan ukuran ducting, jalur ducting, dan jumlah penggunaan ducting. Desain ini menggabungkan unit split saluran yang dimodifikasi, kipas booster, filter pra, filter medium, dan filter HEPA dengan menggunakan saluran aluminium preinsulated sebagai saluran udara. Desain dilakukan dengan menggunakan perangkat lunak AutoCAD 2012, Design Tools Duct Sizer, dan Microsoft Excel. Dari hasil perhitungan dan desain didapatkan kebutuhan kapasitas 3 ruang bedah yaitu ducted ducted 100.000 BTUH sebanyak 3 unit, booster fan 3.3 - 4 Di WG sebanyak 3 unit, pre filter 24 "x 24" x 2 "6 set, filter menengah 610 x 610 x 290 mm 6 set, dan filter HEPA 1220 x 610 x 70 mm 12. Untuk ruang steril, tekanan statis yang dihasilkan oleh unit pendingin harus lebih besar daripada tekanan statis yang dihasilkan dari unit yang ada. di ruang semi steril. Dengan kata lain, ruang steril harus memiliki tekanan positif terhadap ruang semi steril. Hal ini dimaksudkan agar udara di ruang semi steril tidak masuk ke ruang steril ketika pintu antar ruangan dibuka. Desain dan perhitungan ruang bedah, suhu nyata yang diperoleh adalah 23 ° C ± 2 ° C dan kelembaban relatif yang diperoleh adalah 60% ± 2%.   Air conditioning design can also be applied in the health field, with cleanroom standard can be obtained temperature, humidity, comfort and hygiene needed for sterile room (surgical room). The design of air conditioning in this case is done by determining the cooling load required for the sterile room (surgical room), then determining the ducting size, ducting path, and the amount of ducting usage. This design combines modified ducted split unit, booster fan, pre filter, medium filter, and HEPA filter by using preinsulated aluminum duct as an air passage. The design is done by using AutoCAD 2012 software, Design Tools Duct Sizer, and Microsoft Excel. From the calculation and design result obtained the capacity requirement of 3 surgical room that is split ducted 100.000 BTUH as many as 3 units, booster fan 3.3 - 4 In WG as many as 3 units, pre filter 24"x 24" x 2" 6 sets, medium filter 610 x 610 x 290 mm 6 sets, and HEPA filter 1220 x 610 x 70 mm 12 sets. For the sterile room, the static pressure generated by the cooling unit shall be larger than the static pressure generated from the unit present in the semi sterile room. In other words, the sterile room must have positive pressure to the semi sterile room. It is intended that the air in the semi sterile room does not enter into the sterile room when the door between room opened. In this surgical room design and calculation, real temperature obtained is 23 °C ± 2 °C and the relative moisture obtained is 60% ± 2%.

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