scholarly journals INFLUENCES OF LOCAL RESISTANCES OF TECHNOLOGICAL CHANNELS OF PULP AND PAPER PRODUCTION ON THE OPERATION OF VORTEX FLOW METERS OF WATER AND WATER SUSPENSIONS OF LOW CONCEN-TRATIONS

2019 ◽  
pp. 307-314
Author(s):  
Iuriy Davydovich Alashkevich ◽  
Mikhail Semenovich Lur’e ◽  
Ol'ga Mikhaylovna Lur’e ◽  
Aleksandr Sergeyevich Frolov

The question of the features of operation of submersible vortex flowmeters of water and water suspensions of low concentrations in pulp and paper production, which are installed in process pipelines with local hydraulic resistance, is considered. It is shown that with an insufficient straight section after local resistance, an additional error appears, which appears due to the influence of local resistance (transition or retraction) on the symmetry of the velocity diagram in front of the device. This error arises due to a change in the Strouhal number (Sh) and is related to the measurement method. The Strouhal number begins to depend on both the distance to the local resistance and the fluid flow rate. Identify this relationship and is dedicated to this work. Recommendations on the length of straight pipeline sections in front of the flow meter have been developed, which can be significantly reduced by limiting the range of operating flow rates. The studies were carried out by the method of numerical simulation of hydrodynamic processes with subsequent processing of the results by the method of experiment planning. The dependence of the number Sh on the length of the relative diameter of the pipeline L/ for hydrodynamic resistance in the form of a transition is presented. This error shows that the measurement error is within 2% already with a straight section in front of the flowmeter equal to 5–7 diameters. The response surface for pipe bends (rotations) is considered at 90º from which it follows that while maintaining the length of the straight section within 5–7 pipe diameters, it is necessary to narrow the measurement range of the instruments 2.5 times.

2018 ◽  
pp. 273-279
Author(s):  
Юрий (Iuriy) Давыдович (Davydovich) Алашкевич (Alashkevich) ◽  
Михаил (Mikhail) Семенович (Semenovich) Лурье (Lur'e) ◽  
Ольга (Ol'ga) Михайловна (Mikhaylovna) Лурье (Lur'e) ◽  
Александр (Aleksandr) Сергеевич (Sergeevich) Фролов (Frolov)

The issue of operation of submersible vortex flowmeters used in the systems of monitoring of circulating and waste waters of pulp and paper production is considered. It is shown that in the event of an error in the installation of these instruments, an additional error appears due to the angle between the axis of the flow body (TO) of the flowmeter and the axis of the pipeline. This error is related to the measurement method, which in turn leads to a change in the Strouhal number (Sh). The influence of this error leads to a change in the geometry of the flow part of the submerged flowmeter (the appearance of the angle β), which in turn leads to a change in the vortex formation process. Variants of finding this error are considered, from which the method of numerical modeling of hydrodynamic processes with subsequent processing by the method of experiment planning was chosen. For each investigated velocity of the fiber suspension and the angle of deflection of the TO axis, a graph of the frequency spectrum of the vortex formation process was obtained. Which was later used to find the number Sh. The dependence of the installation error ΔSh,% is presented. in the form of a response surface. It is revealed that the error in the installation of the TO, which is estimated by the angle β, is relatively small and varies linearly with increasing β. If the angle β = ± 3 ° is accepted as an allowable value, then the error in measuring the flow rate of the suspension will not exceed 0.25% over the entire range of velocities under consideration.


2009 ◽  
Vol 29 (1) ◽  
pp. 293-308 ◽  
Author(s):  
M.C. Monte ◽  
E. Fuente ◽  
A. Blanco ◽  
C. Negro

2020 ◽  
Vol 8 (02) ◽  
pp. 293-299
Author(s):  
Otoide J. E.* ◽  
Ihinmikaiye, S. O. ◽  
Otoide, T. F.

The possibility of creating wealth in pulp and paper industry from the underutilized dry matters of the leaf sheaths of the pseudostem (Musa paradisiaca and M. sapientum), leaf stalk (Carica papaya) and stems (Panicum maximum and Andropogon tectorum) have been established from the anatomical parameters and indexes (fibre lengths and diameters, lumen width, cell wall thickness, Runkels ratio, flexibility coefficient (%) and slenderness ratio) of the fibres using standard procedures. Results obtained revealed that the Runkels ratio of the fibres in the five dry matters were 0.60, 0.44, 0.40, 0.87 and 0.93 for Musa sapientum, M. paradisiaca, Carica papaya, Panicum maximum and Andropogon tectorum respectively. These values, each been less than 1 (˂ 1) recommends each of the dry matters as suitable alternative source of raw materials for pulp and paper production industry. It was recommended that these dry plant materials be henceforth harnessed as alternative sources of raw materials for pulp and paper production industry as another means of wealth creation instead of allowing them to waste and cause environmental nuisance.


2016 ◽  
Vol 39 (1) ◽  
pp. 27-30
Author(s):  
Shardesh Chaurasia ◽  
Satya Singh ◽  
Sanjay Naithani

Fiber dimensions of Melocanna baccifera was examined to assess their suitability for pulp and paper production. Fifty mature culms of M. baccifera were obtained from Forest of Silchar, Cachar District of Assam, India. Samples taken from the top, middle and basal portions were thoroughly mixed and used in the study.


Cellulose ◽  
2019 ◽  
Author(s):  
María Eugenia Eugenio ◽  
David Ibarra ◽  
Raquel Martín-Sampedro ◽  
Eduardo Espinosa ◽  
Isabel Bascón ◽  
...  

1950 ◽  
Vol 28 (1) ◽  
pp. 23-24
Author(s):  
HARRY F. LEWIS

2020 ◽  
Vol 24 (137) ◽  
pp. 88-97
Author(s):  
F.Kh. Khakimova ◽  
◽  
K.A. Sinyaev ◽  
R.R. Khakimov ◽  
O.A. Noskova ◽  
...  

2020 ◽  
Author(s):  
Guey-Horng Wang ◽  
Teh-Hua Tsai ◽  
Chun-Chi Kui ◽  
Chiu-Yu Cheng ◽  
Tzu-Ling Huang ◽  
...  

Abstract In this study, we constructed recombinant luminescent Escherichia coli with T7, T3, and SP6 promoters inserted between tol and lux genes as toluene biosensors and evaluated their sensitivity, selectivity, and specificity for measuring bioavailable toluene in in groundwater and river water. The luminescence intensity of each biosensor depended on temperature, incubation time, ionic strength, and concentrations of toluene and coexisting organic compounds. Toluene induced the highest luminescence intensity in recombinant lux-expressing E. coli with the T7 promoter [T7-lux-E. coli, limit of detection (LOD) = 0.05 μM], followed by that in E. coli with the T3 promoter (T3-lux-E. coli, LOD = 0.2 μM) and SP6 promoter (SP6-lux-E. coli, LOD = 0.5 μM). Luminescence activities may have been synergistically or antagonistically affected by coexisting organic compounds other than toluene; nevertheless, low concentrations of benzoate and toluene analogs had no such effect. In reproducibility experiments, the biosensors had low relative standard deviation (4.3%–5.8%). SP6-lux-E. coli demonstrated high adaptability to environmental interference. T7-lux-E. coli biosensor—with low LOD, wide measurement range (0.05–500 μM), and acceptable deviation (−14.3% to 9.1%)—is an efficient toluene biosensor. This is the first study evaluating recombinant lux E. coli with different promoters for their potential application in toluene measurement in actual water bodies.


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