scholarly journals A distillation tray with high efficiency and excellent operating flexibility for viscous mixture separation

2014 ◽  
Vol 20 (2) ◽  
pp. 223-231
Author(s):  
Qunsheng Li ◽  
Manxia Zhang ◽  
Zhigang Lei ◽  
Xiaofei Tang ◽  
Lun Li ◽  
...  

The flow-guided sieve-valve tray(FGS-VT)with high efficiency was designed to overcome the shortcoming of low operating flexibility of the flow-guided sieve tray. Its dimensions and geometry, as well as structure characteristics, were presented. The hydrodynamics and mass transfer performance, including dry-plate pressure drop, wet plate-pressure drop, weeping, entrainment and tray efficiency, of two types of FGS-VTs (FGS-VTs with 14 and 8 valves, respectively) and one flow-guided sieve tray were tested in an air-water-oxygen cold model experiment with a 0.6 m diameter plexiglass column. The results demonstrate that FGS-VT with 14 valves works better than FGS-VT with 8 valves, and in comparison with the flow-guided sieve tray, the flow-guided sieve-valve tray with 14 valves has higher tray efficiency, bigger operating flexibility, and lower wet-plate pressure drop (when all the valves are opened fully).Additionally, two typical applications to separate the mixture with high viscosity, solid, powder, easy-to-foam or easy self-polymerization components proved the unique advantages of FGS-VT.

2011 ◽  
Vol 225-226 ◽  
pp. 107-110
Author(s):  
Lan Yi Sun ◽  
Ru Jun Wang ◽  
Cheng Zhai ◽  
Qing Song Li

Fixed valve trays have the advantages of low pressure drop, high efficiency, anti-fouling, simple structure, low manufacture cost and long runtime and therefore have been widely used abroad. This paper presents a new bilayer fixed valve (BFV) tray which has some improvements on traditional fixed valve trays. The hydrodynamic and mass transfer performance of BFV tray, sieve tray and F1 valve tray was experimentally studied with air-water-oxygen system in a 1.2m column. The results showed that the BFV tray possesses low pressure drop, high capacity, wide operating range and high efficiency.


2011 ◽  
Vol 219-220 ◽  
pp. 697-700
Author(s):  
Jun Li ◽  
Lan Yi Sun ◽  
Zhan Hua Ma ◽  
Sha Xue ◽  
Yang Dong Hu

In order to satisfy the revamping of refinery and chemical equipments, a new kind of tray, enhanced jet tray (EJT), was presented. The hydrodynamic and mass transfer performances of EJT and new vertical sieve tray (New VST) were investigated with air-water-oxygen system in a stainless steel column of 1200mm internal diameter. Correlations of hydrodynamic parameters such as pressure drop, weeping and entrainment of EJT were obtained. The experimental results show that EJT has lower pressure drop, fractional weeping, entrainment and higher efficiency compared with New VST because of its special geometry characteristics.


2006 ◽  
Vol 128 (10) ◽  
pp. 1070-1080 ◽  
Author(s):  
Debashis Pramanik ◽  
Sujoy K. Saha

The heat transfer and the pressure drop characteristics of laminar flow of viscous oil through rectangular and square ducts with internal transverse rib turbulators on two opposite surfaces of the ducts and fitted with twisted tapes have been studied experimentally. The tapes have been full length, short length, and regularly spaced types. The transverse ribs in combination with full-length twisted tapes have been found to perform better than either ribs or twisted tapes acting alone. The heat transfer and the pressure drop measurements have been taken in separate test sections. Heat transfer tests were carried out in electrically heated stainless steel ducts incorporating uniform wall heat flux boundary conditions. Pressure drop tests were carried out in acrylic ducts. The flow was periodically fully developed in the regularly spaced twisted-tape elements case and decaying swirl flow in the short-length twisted tapes case. The flow characteristics are governed by twist ratio, space ratio, and length of twisted tape, Reynolds number, Prandtl number, rod-to-tube diameter ratio, duct aspect ratio, rib height, and rib spacing. Correlations developed for friction factor and Nusselt number have predicted the experimental data satisfactorily. The performance of the geometry under investigation has been evaluated. It has been found that on the basis of both constant pumping power and constant heat duty, the regularly spaced twisted-tape elements in specific cases perform marginally better than their full-length counterparts. However, the short-length twisted-tape performance is worse than the full-length twisted tapes. Therefore, full-length twisted tapes and regularly spaced twisted-tape elements in combination with transverse ribs are recommended for laminar flows. However, the short-length twisted tapes are not recommended.


Author(s):  
Licheng Sun ◽  
Kaichiro Mishima

2092 data of two-phase flow pressure drop were collected from 18 published papers of which the working fluids include R123, R134a, R22, R236ea, R245fa, R404a, R407C, R410a, R507, CO2, water and air. The hydraulic diameter ranges from 0.506 to 12mm; Relo from 10 to 37000, and Rego from 3 to 4×105. 11 correlations and models for calculating the two-phase frictional pressure drop were evaluated based upon these data. The results show that the accuracy of the Lockhart-Martinelli method, Mishima and Hibiki correlation, Zhang and Mishima correlation and Lee and Mudawar correalion in the laminar region is very close to each other, while the Muller-Steinhagen and Heck correlation is the best among the evaluated correlations in the turbulent region. A modified Chisholm correlation was proposed, which is better than all of the evaluated correlations in the turbulent region and its mean relative error is about 29%. For refrigerants only, the new correlation and Muller-Steinhagen and Heck correlation are very close to each other and give better agreement than the other evaluated correlations.


2008 ◽  
Vol 2008 ◽  
pp. 1-4 ◽  
Author(s):  
Shaowei Chu ◽  
Ying Zhang ◽  
Bin Wang ◽  
Yong Bi

908 mW of green light at 532 nm were generated by intracavity quasiphase matching in a bulk periodically poled MgO:LiNbO3 (PPMgLN) crystal. A maximum optical-to-optical conversion efficiency of 33.5% was obtained from a 0.5 mm thick, 10 mm long, and 5 mol% MgO:LiNbO3 crystal with an end-pump power of 2.7 W at 808 nm. The temperature bandwidth between the intracavity and single-pass frequency doubling was found to be different for the PPMgLN. Reliability and stability of the green laser were evaluated. It was found that for continuous operation of 100 hours, the output stability was better than 97.5% and no optical damage was observed.


2004 ◽  
Vol 30 (4) ◽  
pp. 509-514 ◽  
Author(s):  
Hideki TOKANAI ◽  
Eiji HARADA ◽  
Jun-ichi HASEGAWA ◽  
Masafumi KURIYAMA

2019 ◽  
Vol 212 ◽  
pp. 699-708 ◽  
Author(s):  
De-Qiang Chang ◽  
Chi-Yu Tien ◽  
Chien-Yuan Peng ◽  
Min Tang ◽  
Sheng-Chieh Chen

Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1026 ◽  
Author(s):  
Lihui Wang ◽  
Xinlong Liu ◽  
Yanjun Jiang ◽  
Peng Liu ◽  
Liya Zhou ◽  
...  

Enzymatic production of biodiesel had attracted much attention due to its high efficiency, mild conditions and environmental protection. However, the high cost of enzyme, poor solubility of methanol in oil and adsorption of glycerol onto the enzyme limited the popularization of the process. To address these problems, we developed a silica nanoflowers-stabilized Pickering emulsion as a biocatalysis platform with Candida antarctica lipase B (CALB) as model lipase for biodiesel production. Silica nanoflowers (SNFs) were synthesized in microemulsion and served as a carrier for CALB immobilization and then used as an emulsifier for constructing Pickering emulsion. The structure of SNFs and the biocatalytic Pickering emulsion (CALB@SNFs-PE) were characterized in detail. Experimental data about the methanolysis of waste oil to biodiesel was evaluated by response surface methodology. The highest experimental yield of 98.5 ± 0.5% was obtained under the optimized conditions: methanol/oil ratio of 2.63:1, a temperature of 45.97 °C, CALB@SNFs dosage of 33.24 mg and time of 8.11 h, which was closed to the predicted value (100.00%). Reusability test showed that CALB@SNFs-PE could retain 76.68% of its initial biodiesel yield after 15 cycles, which was better than that of free CALB and N435.


Author(s):  
Suoton P. Peletiri ◽  
Nejat Rahmanian ◽  
Iqbal M. Mujtaba

There is need to accurately design pipelines to transport the expected increase of CO2 captured from industrial processes after the signing of the Paris Climate Agreement in 2016. This paper reviews several aspects of CO2 pipeline design with emphasis on pressure drop and models for the calculation of pipeline diameter. Two categories of pipeline equations were identified. The first category is independent of pipeline length and has two different equations. This category is used to specify adequate pipeline diameter for the volume of fluid transported. The optimum economic pipe diameter equation (Eq. 17) with nearly uniform resultant velocity values at different flow rates performed better than the standard velocity flow equation (Eq. 20). The second category has four different equations and is used to calculate pipeline pressure drop or pipeline distance for the installation of booster stations after specifying minimum and maximum pipeline pressures. The hydraulic equation is preferred because it gave better resultant velocity values and the closest diameter value obtained using Aspen HYSYS (V.10) simulation. The effect of impurities on the pressure behaviour and optimal pipeline diameter and pressure loss due to acceleration were ignored in the development of the models. Further work is ongoing to incorporate these effects into the models.


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