Analysis of the effects of pressure profile, furnish, and microfibrillated cellulose on the dewatering of papermaking furnishes

TAPPI Journal ◽  
2015 ◽  
Vol 14 (5) ◽  
pp. 325-337 ◽  
Author(s):  
ANTTI KOPONEN ◽  
SANNA HAAVISTO ◽  
JOHANNA LIUKKONEN ◽  
JUHA SALMELA
Keyword(s):  
Pressure Drop ◽  
Flow Rate ◽  
Flow Resistance ◽  
Pressure Profile ◽  
Pilot Scale ◽  
Microfibrillated Cellulose ◽  
Laboratory Scale ◽  
Filtration Process ◽  
Furnish Type ◽  
Solids Content

In this paper, we present an improved experimental method for studying the initial dewatering process in papermaking. We studied the effects of the dewatering pressure profile, the furnish type, and microfibrillated cellulose (MFC) on the development of flow resistance and the final solids content of the filtered sheet. The major difference from the previous studies is the possibility to control the dewatering pressure profile during filtration. The filtration process is monitored by measuring the pressure drop over the filtrated sheet and the flow rate through the filtered sheet as a function of time. In the end, the final solids content is measured. Our results indicate that the sheet solids content after the initial dewatering depends on the magnitude and the shape of the pressure profile used during the filtration and that this dependency remains after wet pressing. Laboratory scale measurements are repeated in pilot scale using a papermaking research environment, with comparable results. Surprisingly, we found that the addition of MFC increases the solids content. This was verified in laboratory and pilot scale studies. Overall, this study shows that laboratory scale measurements can be useful in determining the optimal dewatering conditions for different furnish types.

scholarly journals Performance Comparison of Spiral-Wound and Plate-and-Frame Forward Osmosis Membrane Module

Membranes ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 318
Author(s):  
Sungyun Lee
Keyword(s):  
Pressure Drop ◽  
Flow Rate ◽  
Large Scale ◽  
Forward Osmosis ◽  
Pilot Scale ◽  
Performance Comparison ◽  
Normal Operation ◽  
Membrane Area ◽  
Feed Pressure ◽  
Spiral Wound

We compared two representative forward osmosis (FO) modules—spiral-wound (SW) and plate-and-frame (PF)—to provide practical information for the selection of FO element for a large-scale FO process. The FO operating performance of commercially available SW FO and PF FO was explored under different membrane area and flow rate conditions. The performance trend as a function of the membrane was obtained by adjusting the number of serially connected elements. Although SW FO and PF FO elements exhibited comparable feed pressure drops, SW FO demonstrated a significantly higher draw channel pressure drop than PF FO. Furthermore, the significant draw pressure drop in SW FO increased the draw inlet pressure, consequently limiting the number of serially connected elements. For example, the maximum number of serially connected elements for the normal operation was three elements for SW FO (45.9 m2) but nine elements for PF FO (63 m2) when the flow rate of 10 LMP was applied for feed and draw streams. Additionally, a footprint analysis indicated that SW FO module exhibited a slightly larger footprint than PF FO. Under investigated conditions, PF FO exhibited relatively better performance than SW FO. Therefore, this pilot-scale FO study highlighted the need to reduce the flow resistance of SW FO draw channel to take advantage of the high packing density of the SW element.

scholarly journals Biomass Growth and Its Control in the Process of Biofiltration of Air Contaminated with Xylene on a Biotrickling Column Filled with Expanded Clay

2020 ◽  
Vol 12 (13) ◽  
pp. 5412
Author(s):  
Anita Turała ◽  
Andrzej Wieczorek
Keyword(s):  
Flow Rate ◽  
Flow Resistance ◽  
Gas Flow ◽  
Laboratory Scale ◽  
Biogenic Elements ◽  
Biomass Growth ◽  
Gas Flow Rate ◽  
Average Efficiency ◽  
A Value ◽  
Large Growth

Biofiltration of air polluted with xylene vapors was carried out for nearly two years in a large laboratory-scale installation with a volume of the bed of expanded clay equal to 32 dm3. During the experiment, different xylene inlet concentrations were applied, within the range from 300 to over 1500 mg/m3 at a linear gas flow rate of 0.008, 0.016, and 0.033 m/s, as well as 0.12 and 0.24 dm3 of medium dispensed every 3 h on top of the bed. The progress of the process was followed by measuring the xylene concentration at the inlet and outlet of the column, column mass, and gas flow resistance. The capability to purify air polluted with xylene with an average efficiency of approx. 90% was demonstrated. The process was interrupted by a significant increase in gas flow resistance, caused by a large growth of biomass, resulting in an increase in the mass of the bed by more than 45%. Both intensive rinsing of the bed with a stream of water, causing its fluidization, and rinsing and mixing after removing the bed from the column allowed to reduce flow resistance to a value close to the initial one. To ensure the supply of biogenic elements, it was necessary to periodically spray the bed with a solution of the medium in an amount of up to about 0.1 dm3/h/m3 of purified air.

scholarly journals Design, Scaling, and Development of Biofilters with E crassipes for Treatment of Water Contaminated with Cr (VI)

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1317
Author(s):  
Uriel Fernando Carreño Sayago
Keyword(s):  
Heavy Metal ◽  
Flow Rate ◽  
Genetic Material ◽  
Pilot Scale ◽  
Laboratory Scale ◽  
Adequate Treatment ◽  
Chromium Vi ◽  
Water Treatment Process ◽  
Adsorption Capacities ◽  
The Subject

The heavy metal water treatment process is the subject of worldwide research. Chromium (VI) is a heavy metal that is very dangerous to humans due to it being able to alter genetic material and cause cancer. Cellulose is an interesting material for removing heavy metals, and excellent removals have been achieved in many experiments at the laboratory scale. However, scaling these processes to polluting industries is not easy. The objective of this research is to design, scale, and test a biofilter with biomass of E crassipes transformed with iron for treatment of water contaminated with Cr (VI). The biomasses of E crassipes (EC) and E crassipes with iron (EC + Fe) were evaluated at the batch laboratory scale to determine the adsorption capacities through Langmuir isotherms. With these capacities, a mass balance was formulated, obtaining the design equation to build a biofilter at the pilot scale and providing the required amount of biomass from (EC) and (EC + Fe) for the adequate treatment of the Cr (VI) present in the water. The mass, as suggested by the relevant equations, for the greatest concentration of Cr (VI) of 500 mg/L was 42 g together with a flow rate of 10 mL/min for the biomass of (EC + Fe); for the biomass of (EC), the suggested model for the treatment of the greatest Cr (VI) concentration of 500 mg/L was 64 g of biomass together with a flow rate of 10 mL/min. We conclude that the two pilot-scale treatment systems were consistent with the Cr (VI) removal process and that the equation for the design was adequate.

Relationships Between Supply Flow Rate of Small Cooling Fans and Pressure Drop Characteristics in Electronic Enclosure

2013 ◽  
Author(s):  
Takashi Fukue ◽  
Tomoyuki Hatakeyama ◽  
Masaru Ishizuka ◽  
Koichi Hirose ◽  
Katsuhiro Koizumi
Keyword(s):  
Pressure Drop ◽  
Flow Rate ◽  
Flow Resistance ◽  
High Density ◽  
Thermal Design ◽  
Air Cooling ◽  
Operating Pressure ◽  
Resistance Curve ◽  
Cooling Fans ◽  
High Density Packaging

This study describes a prediction method of a supply flow rate of axial cooling fans mounted in high-density packaging electronic equipment. The performance of an air-cooling fan is defined by its P – Q (pressure difference – flow rate) curve. Generally the operating point of a fan, which is the operating pressure and the flow rate in equipment, is the point of intersection of a P – Q curve and a flow resistance curve. Recently, some researchers reported that catalogue P – Q curves have not necessarily been able to predict a correct supply flow rate in thermal design of high-density packaging equipment. Our study aims to improve prediction accuracy of the supply flow rate. In this report, a relationship between the P – Q curve and a pressure drop characteristic in a fan-mounted enclosure was investigated. A test enclosure which includes an obstruction was mounted in front of a test fan and the supply flow rate of the fan was measured while changing the obstruction. Additionally the flow resistance curves in the test enclosure were measured and the relationship among the supply flow rate, the P – Q curve and the flow resistance curve was investigated. It is found that the correct supply flow rate can be obtained by using the flow resistance from the enclosure inlet through the fan outlet and the revised P – Q curve which is made compensation for the pressure drop at the inlet and the outlet of the fan.

A pilot web former designed to study retention-formation relationships

2010 ◽  
Vol 25 (2) ◽  
pp. 185-194
Author(s):  
Anna Svedberg ◽  
Tom Lindström
Keyword(s):  
Pilot Scale ◽  
Operating Conditions ◽  
Montmorillonite Clay ◽  
Speed Ratio ◽  
Good Reproducibility ◽  
Total Solids ◽  
Retention Aids ◽  
Solids Content ◽  
Relationship Of ◽  
The Relationship

Abstract A pilot-scale fourdrinier former has been developed for the purpose of investigating the relationship between retention and paper formation (features, retention aids, dosage points, etc.). The main objective of this publication was to present the R-F (Retention and formation)-machine and demonstrate some of its fields of applications. For a fine paper stock (90% hardwood and 10% softwood) with addition of 25% filler (based on total solids content), the relationship between retention and formation was investigated for a microparticulate retention aid (cationic polyacrylamide together with anionic montmorillonite clay). The retention-formation relationship of the retention aid system was investigated after choosing standardized machine operating conditions (e.g. the jet-to-wire speed ratio). As expected, the formation was impaired when the retention was increased. Since good reproducibility was attained, the R-F (Retention and formation)-machine was found to be a useful tool for studying the relationship between retention and paper formation.

PAPER PHYSICS. The web structure in relation to the furnish composition and shoe press pulse profiles during wet pressing

2012 ◽  
Vol 27 (4) ◽  
pp. 798-805 ◽  
Author(s):  
Collin Hii ◽  
Øyvind W. Gregersen ◽  
Gary Chinga-Carrasco ◽  
Øyvind Eriksen ◽  
Kai Toven
Keyword(s):  
Porous Structure ◽  
Peak Pressure ◽  
Pulse Length ◽  
Pressure Profile ◽  
Steam Consumption ◽  
Web Structure ◽  
Wet Pressing ◽  
Solids Content ◽  
In The Beginning ◽  
The Web

Abstract This study shows that wet-pressing TMP and DIP with a shoe press pulse may yield similar afterpress solids, provided that an adequate shoe pulse length with similar pressure profile is applied. A wet web with more porous structure in the sheet dewatering (felt) layer seems to contribute to the increased dewatering during wet pressing. In addition, a shoe press pulse with high peak pressure at the end yields higher solids content after wet-pressing and higher bulk compared to a pulse with a peak pressure in the beginning. The increased dewatering during wet-pressing implies a reduction of steam consumption in the dryer.

Hydrolysis of organic wastewater particles in laboratory scale and pilot scale biofilm reactors under anoxic and aerobic conditions

1998 ◽  
Vol 38 (8-9) ◽  
pp. 179-188 ◽  
Author(s):  
K. F. Janning ◽  
X. Le Tallec ◽  
P. Harremoës
Keyword(s):  
Organic Matter ◽  
Mass Balance ◽  
Particulate Organic Matter ◽  
Removal Rate ◽  
Pilot Scale ◽  
Laboratory Scale ◽  
Synthetic Wastewater ◽  
Aerobic Conditions ◽  
Biofilm Reactors ◽  
Hydrolysis Of

Hydrolysis and degradation of particulate organic matter has been isolated and investigated in laboratory scale and pilot scale biofilters. Wastewater was supplied to biofilm reactors in order to accumulate particulates from wastewater in the filter. When synthetic wastewater with no organic matter was supplied to the reactors, hydrolysis of the particulates was the only process occurring. Results from the laboratory scale experiments under aerobic conditions with pre-settled wastewater show that the initial removal rate is high: rV, O2 = 2.1 kg O2/(m3 d) though fast declining towards a much slower rate. A mass balance of carbon (TOC/TIC) shows that only 10% of the accumulated TOC was transformed to TIC during the 12 hour long experiment. The pilot scale hydrolysis experiment was performed in a new type of biofilm reactor - the B2A® biofilter that is characterised by a series of decreasing sized granular media (80-2.5 mm). When hydrolysis experiments were performed on the anoxic pilot biofilter with pre-screened wastewater particulates as carbon source, a rapid (rV, NO3=0.7 kg NO3-N/(m3 d)) and a slowler (rV, NO3 = 0.3 kg NO3-N/(m3 d)) removal rate were observed at an oxygen concentration of 3.5 mg O2/l. It was found that the pilot biofilter could retain significant amounts of particulate organic matter, reducing the porosity of the filter media of an average from 0.35 to 0.11. A mass balance of carbon shows that up to 40% of the total incoming TOC accumulates in the filter at high flow rates. Only up to 15% of the accumulated TOC was transformed to TIC during the 24 hour long experiment.

Study of fluid flow through a channel deformed by piezoelement

2018 ◽  
Vol 13 (3) ◽  
pp. 1-10 ◽  
Author(s):  
I.Sh. Nasibullayev ◽  
E.Sh Nasibullaeva ◽  
O.V. Darintsev
Keyword(s):  
Fluid Flow ◽  
Pressure Drop ◽  
Boundary Conditions ◽  
Flow Rate ◽  
Contact Surface ◽  
Piezoelectric Element ◽  
Neumann Boundary ◽  
Differential Pressure ◽  
Physical Parameters ◽  
Flow Through

The flow of a liquid through a tube deformed by a piezoelectric cell under a harmonic law is studied in this paper. Linear deformations are compared for the Dirichlet and Neumann boundary conditions on the contact surface of the tube and piezoelectric element. The flow of fluid through a deformed channel for two flow regimes is investigated: in a tube with one closed end due to deformation of the tube; for a tube with two open ends due to deformation of the tube and the differential pressure applied to the channel. The flow rate of the liquid is calculated as a function of the frequency of the deformations, the pressure drop and the physical parameters of the liquid.

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