scholarly journals Experimental Investigation of the Effects of Helical Roof on the Performance of Stairmand High Efficiency Cyclone

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Aykut Karadeniz ◽  
Selami Demir
Keyword(s):  
Pressure Drop ◽  
Treatment Cost ◽  
High Efficiency ◽  
Negative Impact ◽  
Collection Efficiency ◽  
Operating Conditions ◽  
Reduced Pressure ◽  
Particle Collection ◽  
Standard Design ◽  
Roof Design

Cost-effectiveness of a standard and a modified Stairmand high-efficiency type cyclone was compared at various inlet gas velocities. The modified design was obtained by replacing the roof of the standard design with a helical roof. Experiments were conducted by both standard and helical roof designs at the same operating conditions. Results showed that helical roof leads to reduced pressure drop in cyclones while having a negative impact on particle collection efficiency. Reductions in pressure drop can reach up to 30%, while particle collection efficiency is reduced by up to 8% simultaneously. Overall, the treatment cost of a cyclone separator can be reduced by 14.1–20.8%. Results indicated that helical roof design cyclones can be used to reduce overall treatment cost by cyclone separators.

The Study of the Particles Size Influence on the Venturi Scrubbers Perfomance

2008 ◽  
Vol 591-593 ◽  
pp. 322-327
Author(s):  
João Jorge Ribeiro Damasceno ◽  
M.S.C. Gama ◽  
N.C. Silva
Keyword(s):  
Respiratory System ◽  
High Efficiency ◽  
Collection Efficiency ◽  
Industrial Process ◽  
Chronic Illnesses ◽  
Circular Section ◽  
Particle Collection ◽  
Liquid Injection ◽  
Pulmonary Damage ◽  
Mechanical Devices

The suspended particles in the air are a factor that causes chronic illnesses to the respiratory system, which go from allergy to severe pulmonary damage. Particulary, breathable particles (from 0,5 μm to 5,0 μm sizes) cause damages to the respiratory system. The penetration and the deposition are the reason for the damages to the pulmonary alveolus. The industrial activity is the main responsible for the most part of the breathable particles emission. Because of that, Venturi scrubbers have been incorporated to the industrial process due to their high efficiency for particle collection. Venturi scrubbers are gas-atomizing devices. They are mechanical devices which rely on shearing and impaction forces to break water into fine droplets. Those droplets in contact with the particles, will collected them. This work consists of a Venturi scrubber of circular section operating horizontally, with liquid injection through a single orifice located in the scrubber throat. The experiments will analyse the influence of the length throat, gas velocity, liquid flow and particles sizes on the Venturi´s collection efficiency.

scholarly journals Performance of a cyclone scrubber on removal of fine particulate matter

2020 ◽  
Vol 26 (1) ◽  
pp. 31-40
Author(s):  
Ana Achiles ◽  
Vádila Guerra
Keyword(s):  
Pressure Drop ◽  
Sugar Cane ◽  
Gas Flow ◽  
High Efficiency ◽  
Fine Particles ◽  
Collection Efficiency ◽  
Sugar Cane Bagasse ◽  
Flow Ratio ◽  
Liquid Injection ◽  
Gas Flow Ratio

Cyclones are not classified as effective devices for removing fine particles, while high efficiency wet scrubbers usually have high operational costs. In order to achieve better performance, the aim of this study is to evaluate, for the first time, a cyclone scrubber design based on the dimensions of a Stairmand cyclone separator with the inclusion of liquid injection nozzles located in different positions to improve the separation of fine particles. Given the lack of studies considering the effect of liquid injection and other operational conditions in the removal performance of a cyclone scrubber with Stairmand dimensions, the present paper provides a complete evaluation of these effects for the separation of sugar cane bagasse ash from air. The parameters investigated were inlet gas velocity, liquid injection position, liquid-to-gas flow ratio and droplet size distribution. The cyclone scrubber performance was evaluated considering collection efficiency and pressure drop. Overall efficiency of almost 99% and low-pressure drop was achieved by employing a liquid-to-gas flow ratio of 0.43 L/m? for the collection of ash from the combustion of sugar cane bagasse. Grade efficiencies revealed that injecting droplets into cyclones significantly improved the removal of fine particles with an aerodynamic diameter less than 2.5 ?m.

Comparative Analysis of Various CFBC Cyclone Separator REPDS Profiles

2017 ◽  
Vol 9 (1) ◽  
Author(s):  
N. Prasanna ◽  
R.S. Prakash ◽  
M. Vijayakumar
Keyword(s):  
Pressure Drop ◽  
Circulating Fluidized Bed ◽  
Collection Efficiency ◽  
Cyclone Separator ◽  
Fluidized Bed Combustion ◽  
Reduced Pressure ◽  
Denudation Rate ◽  
Computational Fluid Dynamics Analysis ◽  
Vortex Finder ◽  
Circulating Fluidized Bed Combustion

In the last decade research on CFBC (Circulating Fluidized Bed Combustion Boiler) has been increased but research on cyclone separator has not been paid well attention. All the existing designs of cyclone separator were mainly concentrating on a single parameter that is collection efficiency. But this work mainly concentrates on other parameters like pressure drop and denudation rate. Previous works related to cyclone separator having REPDS (Reduced Pressure Drop Stick) suggest that 50% REPDS in the vortex finder gives the optimum results for all the existing cyclone models. Existing REPDS profile is only circular; we attempted to change the REPDS profile to polygon shapes like square, hexagonal. All the cyclone separators with different REPDS profile have been designed for flow rate of 500m3/hr with operating velocity of 15m/s. CFD (Computational Fluid Dynamics) analysis has been done with operating velocity ranging from 15m/s to 30m/s, using K-€ turbulence model. The results obtained in CFD analysis reveal that there is no much variation in pressure drop, but there is a drastic change in the denudation rate while operating CFBC cyclone separator twice the designed velocity. Thus REPDS can be included in vortex finder of cyclone separator with any polygon profiles as mentioned above.

Effect of variation of cylindrical pin fins height on the overall performance of microchannel heat sink

2019 ◽  
Vol 233 (5) ◽  
pp. 980-990 ◽  
Author(s):  
Mohammad Owais Qidwai ◽  
Mohammad Muzaffarul Hasan
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Heat Sink ◽  
High Efficiency ◽  
Rectangular Channel ◽  
Microchannel Heat Sink ◽  
Reduced Pressure ◽  
Number Range ◽  
Pin Fin ◽  
Downstream Region

Numerous researches are performed to take account of the heat transfer in the microchannel heat sink, due to its high efficiency and application in various fields of microelectronics. An attempt has been made to numerically investigate the effects of variation of cylindrical pin fin height, entrenched on bottom wall of microchannel. Three cases of microchannel heat sink are prepared: case 1: plain rectangular channel; case 2 and case 3 with decreasing pin fin height and with increasing pin fin height in the direction of flow, respectively. Also, diameter of pin fin is varied to obtain effects of any underlying flow feature on heat transfer augmentation. The analysis is performed for single-phase fluid deionized ultra-filtered water with temperature-dependent properties, for low Reynolds number range of 150–300. Higher Nusselt number is obtained for case 2, whereas lower pressure drop is obtained in case 3. The overall thermal performance of case 3 with increasing pin fin height outperforms the corresponding case 2 with decreasing pin fin height for the same pin fin diameter, due to the velocity distribution and reduced pressure drop in the downstream region in microchannel, which shows that the downstream region of microchannel heat sink has a significant impact in terms of the overall efficiency while establishing pressure drop as essential characteristics.

Pressure Drop and Aerosol-Particle-Collection Efficiency of Polydisperse Fibrous Filters

2018 ◽  
Vol 80 (3) ◽  
pp. 331-338 ◽  
Author(s):  
A. L. Chernyakov ◽  
A. A. Kirsh
Keyword(s):  
Pressure Drop ◽  
Aerosol Particle ◽  
Collection Efficiency ◽  
Particle Collection ◽  
Fibrous Filters

scholarly journals KAJIAN KINERJA SIKLON PEMBERSIH DAN PENGARUHNYA TERHADAP KONSENTRASI GAS-GAS HASIL GASIFIKASI TANDAN KOSONG KELAPA SAWIT

2020 ◽  
Vol 21 (3) ◽  
pp. 211-218
Keyword(s):  
Pressure Drop ◽  
Oil Palm ◽  
Collection Efficiency ◽  
Operating Conditions ◽  
Empty Fruit Bunch ◽  
Gas Temperature ◽  
Empty Fruit Bunches ◽  
Purification System ◽  
Standard Pressure

ABSTRAK PPembersihan partikel-partikel pengotor dari gas-gas hasil gasifikasi tandan kosong kelapa sawit merupakan salah satu proses penting yang harus dilakukan untuk mendapatkan gas pembawa energi dengan kemurnian yang lebih baik. Pemisahan partikel-partikel tersebut dari umumnya dilakukan dengan menggunakan siklon. Konstruksi dan kondisi operasi siklon, seperti suhu gas yang masuk, berperan penting dalam menentukan kinerja pemisahan partikel dari gas tersebut. Penelitian ini bertujuan untuk mengkaji pengaruh perubahan suhu gas terhadap kinerja siklon dalam memisahkan partikulat dan tar dari gas-gas hasil gasifikasi tandan kosong kelapa sawit. Hasil kajian menunjukkan bahwa peningkatan suhu gas yang masuk ke siklon mampu memisahkan partikel berukuran 5–6 μm di kisaran suhu 200–300 °C pada efisiensi minimum 50%. Hasil perhitungan efisiensi pengumpulan rata-rata mencapai 98,23%, sedangkan hasil pengukuran adalah 85,56%. Hasil perhitungan dan ekperimen terhadap tekanan jatuh pada siklon, masing-masing, adalah 100,11 dan 87 mmH2 O, berada pada kisaran standar tekanan jatuh yang disarankan. Efisiensi dan tekanan jatuh yang diperoleh menunjukkan bahwa siklon dapat bekerja dengan baik. Hasil kajian menunjukkan bahwa siklon sebaiknya digunakan pada tahap awal dari proses pemisah partikel dari gas hasil gasifikasi, pada saat suhu gas masih tinggi Kata kunci : Efisiensi Pengumpulan; Pengurangan Diameter; Penurunan Tekanan; Suhu Gas; Tar ABSTRACT Gas purification is one of a very crucial process required to be performed in order to obtain a better quality of gasses produced by grasification of oil palm empty fruit bunches. A cyclone is usually used in the purification process to separate particles and tarss from the gas. Particle separating performance of a cyclone is affected by its construction and operating conditions, such as temperature of the entering gas. The objectives of this study is to examine the effect of the entering gas temperature to the cyclone performance in separating particulates and tar from gases produced by gasification of oil palm empty fruit bunch. The results shows that the cyclone was capable in separating particles with size of 5-6 μm at entering gas temperature range of 200- 300 °C, at a minimum efficiency of 50%. The calculated average collection efficiency was 98.23% while the experimental results were 84.56%. Calculation and experimental data on pressure drop within the cylone was 100.11 and 97.0 mmH2 O, respectively, and fall within the required standard pressure drop. The collection efficiency and pressure drop indicated that the cyclone performed well. The study also suggests that cyclone is best to be used at the first row of the purification system for gases produced by gasification of empty fruit bunch since the temperature is still high enough Keywords : Collection Efficiency; Diameter Cut Size; Pressures Drop; Temperature of Gas; Tar

scholarly journals Workplace Exposure to Titanium Dioxide Nanopowder Released from a Bag Filter System

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Jun Ho Ji ◽  
Jong Bum Kim ◽  
Gwangjae Lee ◽  
Jung-Hun Noh ◽  
Se-Jin Yook ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
High Efficiency ◽  
Collection Efficiency ◽  
Particle Diameter ◽  
Development Stage ◽  
Bag Filter ◽  
High Exposure ◽  
Filter System ◽  
Particle Collection ◽  
Computational Fluid Dynamics Cfd

Many researchers who use laboratory-scale synthesis systems to manufacture nanomaterials could be easily exposed to airborne nanomaterials during the research and development stage. This study used various real-time aerosol detectors to investigate the presence of nanoaerosols in a laboratory used to manufacture titanium dioxide (TiO2). The TiO2nanopowders were produced via flame synthesis and collected by a bag filter system for subsequent harvesting. Highly concentrated nanopowders were released from the outlet of the bag filter system into the laboratory. The fractional particle collection efficiency of the bag filter system was only 20% at particle diameter of 100 nm, which is much lower than the performance of a high-efficiency particulate air (HEPA) filter. Furthermore, the laboratory hood system was inadequate to fully exhaust the air discharged from the bag filter system. Unbalanced air flow rates between bag filter and laboratory hood systems could result in high exposure to nanopowder in laboratory settings. Finally, we simulated behavior of nanopowders released in the laboratory using computational fluid dynamics (CFD).

Investigations on Performance of Stirling Engine Regenerator Matrix

2011 ◽  
Author(s):  
D. J. Shendage ◽  
S. B. Kedare ◽  
S. L. Bapat
Keyword(s):  
Pressure Drop ◽  
Penetration Depth ◽  
High Efficiency ◽  
Stirling Engine ◽  
Operating Conditions ◽  
Dead Volume ◽  
Working Fluid ◽  
Geometrical Parameters ◽  
Wire Radius ◽  
Thermal Penetration Depth

Stirling engine technology has attracted attention due to recent environmental and energy problems. The regenerator is the main component in high efficiency Stirling engines. A suitable regenerator must be designed for each Stirling machine to provide high performance. The aim of the present work is to find a feasible number of screens in regenerator by taking into account the pressure drop, dead volume, the thermal penetration depth and geometry of regenerator. The second order cyclic analysis with realistic assumptions is carried out for a single cylinder, beta Stirling engine with rhombic drive for predecided operating conditions, such as pressure of 30 bar, hot side temperature of 750 K, speed of 1440 rpm and hydrogen as the working fluid. It is intended to design and develop the Stirling engine with capacity ≥ 1.5 kWe and the efficiency of drive mechanism and alternator is assumed as 85% each. Miyabe’s and Martini’s approaches are used to simulate regenerator performance considering non-sinusoidal motion of displacer and piston. The results reveal that the flow loss increases remarkably to attain higher value of regenerator effectiveness. However, increase in the speed results into an increase in the mass flow rate of the working fluid. It is observed that regenerator effectiveness decreases only marginally over the range of speeds considered. It is also ensured for selected regenerator screen that the thermal penetration depth (239 μm) should be greater than wire radius of mesh (20.5 μm). For present set of operating and geometrical parameters, length of regenerator is fixed as 22 mm which gives regenerator effectiveness as 0.965. Further, the practice to fill more screens than the designed number of screens in the regenerator, while assembling is not advantageous. It increases pressure drop which results in reduced power output. These are some of the important conclusions.

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