- A novel dual element foil (DEF) rotor was developed to improve stickies removal efficiency in paper recycling screening while using less power than conventional rotors.
- In a mill trial, the DEF rotor achieved 42% lower power consumption than the existing rotor at an optimized lower tip speed, while maintaining screen capacity and runnability. It also achieved higher stickies removal efficiency.
- The DEF rotor design optimizes the negative pressure pulse for cleaning while minimizing the positive pulse that could force stickies through slots. This allows for more efficient screening at lower tip speeds and power usage.
This document discusses the determination of the Bond work index of limestone samples from Lucky Cement Limited in Pakistan. The Bond work index test involves grinding limestone samples in a ball mill and measuring the grindability over multiple cycles. Test results found that 6 of 7 limestone samples had a Bond work index over 20 kWh/t, qualifying them as "hard rock." However, one sample from Face-4A had a Bond work index under 20 kWh/t, indicating it was less energy intensive to grind and had higher grindability than the other samples. This study aims to help optimize energy efficiency in limestone grinding operations at Lucky Cement.
This document provides a literature review and overview of rolling processes and power parameters. It discusses key terms related to rolling, the principles of rolling processes, hot rolling and cold rolling, rolling materials, torque in rolling, and power in rolling. The main points are:
- Rolling is a metal forming process that reduces thickness or changes cross-section of a workpiece by compressive forces from rolls.
- Key terms include ingot, bloom, billet, plate, strip, and foil which describe intermediate and final rolled products.
- Hot and cold rolling processes are described along with their effects on material properties.
- Formulas for calculating torque and power in rolling are presented which factor in parameters like rolling
This document provides information on centrifugal barrel finishing (CBF), including:
1) CBF is a mass finishing process that can deburr, finish edges and surfaces, and impart high compressive stresses to improve fatigue resistance of metal components at very high speeds.
2) Recent developments have extended CBF capabilities to handle more complex components and improved productivity with new automatic centrifugal barrels and versatile equipment.
3) CBF works by loading components into barrels mounted on a rapidly rotating turret, along with media. The rapid rotation imparts centrifugal forces up to 50 times gravity, tightly compacting the load and enabling short process times through smooth sliding of media against components.
This document summarizes recent developments in centrifugal barrel finishing (CBF), a mass finishing process used to deburr and finish metal components. Key points:
1) New CBF equipment includes larger, lower-speed machines for less complex work, and automated machines for high production and in-line operation.
2) Removable drums allow preloading and remote reloading for improved utilization and scheduling.
3) Specialized machines can handle large/long parts or precision work through fixturing.
4) Automated machines provide fully automatic loading, processing, unloading and media handling.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Recent advances in spindle finishing technology have expanded its production capabilities. High pressure spindle finishing and continuous spindle finishing allow for faster cycle times. High pressure spindle finishing uses baffles and domes to increase media velocity and confinement, generating higher finishing forces for faster removal rates up to 5-10 times faster. Continuous spindle finishing uses multiple spindles on a rotating head to keep parts immersed continuously, increasing output by up to 100% compared to standard spindle machines where spindles pivot in and out of the media.
Effect of tip clearance on performance of a centrifugal compressoreSAT Journals
Abstract The centrifugal compressor is to study the effect of tip clearance on the performance characteristics and the wall static pressure for a different flow co-efficient. The method of testing the compressor is run at a constant speed at 2000rpm. The tip clearance is varied by using spacers. The volume flow rate is varied with the help of throttling device to conduct the performance test. The performance characteristic of the centrifugal compressor showing the variation of discharge pressure with volume flow rate is plotted. Obtaining the performance characteristics showing the variation of discharge pressure with volume flow rate for different tip clearance, viz. =2.2%, 4%, 6.1% and 7.9%. Measurement of periodic pressure at various tip clearance viz. =2.2%, 4%, 6.1% and 7.9%. For each tip clearance pressure measured in radial location of impeller at 6 positions for different flow co efficient values. Five flow coefficients viz., ф =0.40, =0.34 (both above design flow), =0.28 (near design flow), =0.21=0.18 (both below design flow) and four values of non-dimensional tip clearance viz., =2.2%, 4%, 6.1% and 7.9%, are chosen for experimental work. The objective of the research work is to measure the periodic variation static pressure on the casing over the rotor at different values of tip clearance and flow coefficients. With the availability of these data, it is possible to improve the tip clearance flow in centrifugal compressor.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
This document discusses the determination of the Bond work index of limestone samples from Lucky Cement Limited in Pakistan. The Bond work index test involves grinding limestone samples in a ball mill and measuring the grindability over multiple cycles. Test results found that 6 of 7 limestone samples had a Bond work index over 20 kWh/t, qualifying them as "hard rock." However, one sample from Face-4A had a Bond work index under 20 kWh/t, indicating it was less energy intensive to grind and had higher grindability than the other samples. This study aims to help optimize energy efficiency in limestone grinding operations at Lucky Cement.
This document provides a literature review and overview of rolling processes and power parameters. It discusses key terms related to rolling, the principles of rolling processes, hot rolling and cold rolling, rolling materials, torque in rolling, and power in rolling. The main points are:
- Rolling is a metal forming process that reduces thickness or changes cross-section of a workpiece by compressive forces from rolls.
- Key terms include ingot, bloom, billet, plate, strip, and foil which describe intermediate and final rolled products.
- Hot and cold rolling processes are described along with their effects on material properties.
- Formulas for calculating torque and power in rolling are presented which factor in parameters like rolling
This document provides information on centrifugal barrel finishing (CBF), including:
1) CBF is a mass finishing process that can deburr, finish edges and surfaces, and impart high compressive stresses to improve fatigue resistance of metal components at very high speeds.
2) Recent developments have extended CBF capabilities to handle more complex components and improved productivity with new automatic centrifugal barrels and versatile equipment.
3) CBF works by loading components into barrels mounted on a rapidly rotating turret, along with media. The rapid rotation imparts centrifugal forces up to 50 times gravity, tightly compacting the load and enabling short process times through smooth sliding of media against components.
This document summarizes recent developments in centrifugal barrel finishing (CBF), a mass finishing process used to deburr and finish metal components. Key points:
1) New CBF equipment includes larger, lower-speed machines for less complex work, and automated machines for high production and in-line operation.
2) Removable drums allow preloading and remote reloading for improved utilization and scheduling.
3) Specialized machines can handle large/long parts or precision work through fixturing.
4) Automated machines provide fully automatic loading, processing, unloading and media handling.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Recent advances in spindle finishing technology have expanded its production capabilities. High pressure spindle finishing and continuous spindle finishing allow for faster cycle times. High pressure spindle finishing uses baffles and domes to increase media velocity and confinement, generating higher finishing forces for faster removal rates up to 5-10 times faster. Continuous spindle finishing uses multiple spindles on a rotating head to keep parts immersed continuously, increasing output by up to 100% compared to standard spindle machines where spindles pivot in and out of the media.
Effect of tip clearance on performance of a centrifugal compressoreSAT Journals
Abstract The centrifugal compressor is to study the effect of tip clearance on the performance characteristics and the wall static pressure for a different flow co-efficient. The method of testing the compressor is run at a constant speed at 2000rpm. The tip clearance is varied by using spacers. The volume flow rate is varied with the help of throttling device to conduct the performance test. The performance characteristic of the centrifugal compressor showing the variation of discharge pressure with volume flow rate is plotted. Obtaining the performance characteristics showing the variation of discharge pressure with volume flow rate for different tip clearance, viz. =2.2%, 4%, 6.1% and 7.9%. Measurement of periodic pressure at various tip clearance viz. =2.2%, 4%, 6.1% and 7.9%. For each tip clearance pressure measured in radial location of impeller at 6 positions for different flow co efficient values. Five flow coefficients viz., ф =0.40, =0.34 (both above design flow), =0.28 (near design flow), =0.21=0.18 (both below design flow) and four values of non-dimensional tip clearance viz., =2.2%, 4%, 6.1% and 7.9%, are chosen for experimental work. The objective of the research work is to measure the periodic variation static pressure on the casing over the rotor at different values of tip clearance and flow coefficients. With the availability of these data, it is possible to improve the tip clearance flow in centrifugal compressor.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Design and Development of a Low Cost Handheld Vacuum Cleanerijtsrd
A vacuum cleaner, like many other home products, is made to use it easier and more e icient for its customers to complete particular tasks. It must be effective at both collecting up dust particles and eliminating them from the air. This research paper develops a low cost effective vacuum cleaner and its parts. According to the literature review, the vacuum cleaner’s performance is mostly influenced by parameters including the impeller’s diameter, radius of curvature, strength, and speed. In this study, an unique impeller is designed with Creo, and the flow characteristics of the impeller are examined using CFD. The impeller’s thickness, form, and number of blades are all determined using the mechanical design process. In addition, polycarbonate was used as a material for making impeller in 3D printing. Dr. Velumani Subramaniam | Bhuvanesh Kumar V | Midun K | Mohanprasath G "Design and Development of a Low Cost Handheld Vacuum Cleaner" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-6 | Issue-7 , December 2022, URL: https://www.ijtsrd.com/papers/ijtsrd52404.pdf Paper URL: https://www.ijtsrd.com/engineering/mechanical-engineering/52404/design-and-development-of-a-low-cost-handheld-vacuum-cleaner/dr-velumani-subramaniam
IRJET-Split Casing Open Differential without Cross Pin and it’s Comparison wi...IRJET Journal
This document summarizes the design optimization of work roll chocks and backup roll chocks in a cold rolling mill. The current chocks were failing prematurely, resulting in production stoppages and costs. A 3D model of the chocks was created and analyzed using ANSYS software to determine stress distributions and critical areas under load. The design was iteratively optimized to reduce weight and material costs while maintaining structural integrity. The optimized design was found to reduce chock weight by over 10% and save $9,154.50 per chock based on material and production costs. Modal analysis confirmed the natural frequencies of the optimized design would not cause resonance issues. This new optimized chock design was concluded to provide improved life and cost
Paper cutting & rewinding machine project report SREESANGH P GHOSHSreesangh P Ghosh
The document provides details about the components of a paper cutting and rewinding machine. The main components are a rigid frame, four rollers mounted on plummer blocks with ball bearings to support rotation, a 1 Hp induction motor, a single V-belt and pulley system to transfer motion from the motor to one roller, a C-clamp cutter to cut paper, and nuts and bolts to assemble the components. The machine cuts paper and rewinds it onto rolls in a simple, compact design suitable for small industries.
Carbide Doctor Blades on Ceramic Press RollsKadant Inc.
Ceramic press rolls have become popular choices for improving papermaking efficiency and product quality. The proper selection and use of ceramic-tipped doctor blades and cleaning shower systems is critical in getting the highest performance from these rolls.
This document summarizes research on 3D printing hollow compounds of different shapes. It discusses how 3D printing allows for more optimized geometries compared to traditional manufacturing and can produce hollow turbine blades, gears, and disc brakes with properties similar to solid compounds. Finite element analysis was performed on hollow and solid shapes of different cross-sections, finding equivalent stresses were approximately the same. 3D printing reduces material costs and makes manufacturing hollow compounds easier compared to traditional methods. The document concludes 3D printing technologies provide design flexibility while creating parts with layer-by-layer printing instead of traditional manufacturing approaches.
Drive Power and Torque in Paper Machine DryersKadant Inc.
basic parameter in the design of a paper machine dryer drive system, whether it has an open gear, enclosed gear, or felt drive, is the drive power requirement. Previous work on the drive power for paper machine dryers covered a 1.5 meter diameter cylinder. This paper presents the results for both 1.5 and 1.83 meter diameter cylinders with and without dryer bars.
IRJET- Effect of Contaminated Oil on Temperature Variation of Tilting Pad...IRJET Journal
This document summarizes a study on the effect of contaminated oil on the temperature variation of tilting pad thrust bearings with bronze pads having a catenoidal surface profile. The study involved performing experiments on a test rig with 8 bronze pads under varying speeds, loads, and cooling flow rates. Temperature sensors were placed in a grid pattern over one of the pads to measure temperature changes at different locations. Results showed that adding contaminated powder to the lubricant caused fluid temperatures to increase more with higher thrust loads compared to using non-contaminated oil. The maximum temperature also shifted towards the trailing edge of the pad.
Need of Lapping Machine for Valve Component: A Case StudyIJMER
ABSTRACT: Lapping process is characterized by its low speed, low pressure, and low material removal rate. This process
is used in achieving finer surfaces and closer fits, correction of minor imperfections, and maintaining close tolerances.
During the process of lapping, the mechanisms of surface formation and removal rate are decisively influenced by
the movement type of the individual grains within the lapping abrasive. A gate valve is used to start and stop the flow of
fluid. So the wedge and seat ring of a valve are in continuous pressure of fluid flow and due to opening and closing of valve
these component get wear and they need lapping during reconditioning. This paper will share the need, requirement and
application of lapping during the reconditioning of valve.
This paper will explore the current working condition of lapping machine in valve industry. It will elaborate the
effect of abrasive particals, working speed, surface roughness and other related parameters. What are the difficulties they
are facing during the valve reconditioning related to lapping, will be disscussed.Current set up and the changes required in
this model are suggested with the proposed model.
Key words: Lapping process, wedge, seat ring, abrasive particles.
Design and Fabrication of advanced Abrasive flow machine for superfinishing m...IRJET Journal
This document describes the design and fabrication of an advanced abrasive flow machining (AFM) system for superfinishing machine parts. It discusses the key components of the AFM system including the machine, media, and tooling. The machine components like the piston assembly, media cylinders, fixtures, and hydraulic power pack are designed to operate at pressures up to 10 MPa. Formulas are provided for calculating dimensions of these components to withstand operating pressures. The document also summarizes the sequence of AFM operation and presents surface roughness results indicating the system is capable of achieving a final roughness of 0.120 microns on EN8 steel.
This document discusses optimizing cement grinding circuits through pre-crushing of clinker using a Barmac crusher prior to grinding in a two-compartment ball mill. Bond calculations and population balance modeling are used to analyze the potential benefits. Modeling suggests the total energy consumption for grinding can be reduced up to 10% by pre-crushing clinker to a finer size before ball milling. A case study of a cement plant found pre-crushing could lower the required ball mill power by 9-15% and increase grinding circuit capacity with relatively low capital investment compared to alternatives like high-pressure grinding rolls.
The document summarizes the tube hydroforming process used to form a complex exhaust duct part from thin-walled tube stock. A 400-ton press and custom hydroforming module were used to form the part by pressurizing water inside the tube against the contours of a split die set. Process parameters like pressure and feed rate had to be carefully controlled. The result was an 80% increase in circumference with only 9% wall thinning achieved in the part. Overall tube hydroforming was found to be an economical alternative to previous multi-piece welded construction of this type of part.
This document summarizes the design analysis and testing of an external gear pump developed to deliver 24.55 liters per minute of hydraulic oil. The gears and housing were designed based on available gear design standards and theories to meet the desired flow rate. Testing showed the pump achieved a maximum flow rate of 20 liters per minute with a volumetric efficiency of 81.47%. Flow rate decreased with increasing pressure at a rate of -0.344 liters per meter. The pump was fabricated locally from 0.4% carbon hot-rolled steel.
IRJET- Development of a Modified Tesla TurbineIRJET Journal
This document describes the development of a modified Tesla turbine. Key points:
- Tesla turbines use smooth disks instead of blades, relying on the viscosity and adhesion of fluid to rotate the disks. This makes them simpler and cheaper to produce than traditional bladed turbines.
- The researchers fabricated a Tesla turbine with disks containing variable depth dimples on the periphery to increase the boundary layer effect and cohesion of airflow.
- Testing showed disks with dimples rotated faster (13448 RPM) than smooth disks (12000 RPM) at a 5 bar inlet pressure, demonstrating increased efficiency from the dimple modifications.
The Rotosolver II is a high shear mixer developed by Admix to improve on their existing Rotosolver design. It delivers enhanced performance and efficiency through several design improvements:
1. It reduces energy consumption by up to 30% through streamlining and utilizing computational fluid dynamics software during development.
2. It improves dispersion by providing over 115% more mechanical high shear surface area and more than doubling the number of shearing edges.
3. It features an easy-to-clean design with an open mixing chamber to allow for thorough cleaning.
The document is a project seminar submitted by Mr. Rahul Raju Kundiya on the topic of experimental analysis and modelling in micro drilling of CFRP-Ti6Al4V stacked composite materials. It discusses micro drilling, the objectives of the study, experimental setup, design of experimentation, results and discussion. The study aims to design experiments to analyze the effect of drilling parameters on hole quality and develop a mechanistic force model. It presents results on hole taper, radial overcut, delamination factor and burr formation when drilling the composite material stack at different speeds and feed rates.
IRJET- Design and Performance Curve Generation by CFD Analysis of Centrifugal...IRJET Journal
This document discusses the design and CFD analysis of a centrifugal pump to generate performance curves. A team of students and professors used software like Pro-E, ANSYS, and CFX to design the impeller and volute casing of the pump, generate meshes, and perform the CFD analysis. The CFD analysis provides pressure distributions and helps optimize the design to reduce cavitation and improve efficiency over a range of operating conditions. Performance curves showing head, power, and efficiency versus flow rate will be plotted to evaluate the pump design and aid in pump selection.
IRJET- Design, Manufacturing and Testing of Open-Circuit Subsonic Wind Tunnel...IRJET Journal
This document provides a comprehensive review of the design, manufacturing, and testing of open-circuit subsonic wind tunnels. It discusses key components like the test section, contraction cone, diffuser, and drive system. For the settling chamber and honeycomb structure, the document recommends a length 5-10 times the diameter to reduce lateral turbulence, and notes hexagonal cells have the lowest pressure drop. It states the contraction ratio should be between 7-12 for optimum performance to eliminate axial flow fluctuations. The document also categorizes wind tunnels as open-circuit or closed-circuit, and describes classifications based on airflow speed like subsonic, transonic, supersonic, and hypersonic.
This document discusses how combining high-energy finishing equipment with dry process media technology can improve surface finishes, reduce costs, and address effluent disposal problems from wet finishing processes. Specifically, it outlines how centrifugal barrel finishing (CBF) equipment using dry media can produce reflective finishes comparable to hand buffing in shorter cycle times. It provides examples of manufacturers reducing finishing times from 48 hours to 4 hours and eliminating effluent discharge by switching to CBF with dry media. The document also discusses the benefits of dry media for deburring and polishing precious metals without difficultly reclaiming precious metal fines.
Performance Optimization of Steam Jet Ejector Using CFD A ReviewIRJET Journal
This document discusses optimization of steam jet ejector geometry for refrigeration applications using computational fluid dynamics (CFD). It provides background on jet ejectors and their operating principle. The purpose is to optimize ejector geometry to improve efficiency by reducing pressure drop. An extensive literature review is presented that investigated the effects of geometrical parameters like nozzle size and shape, mixing chamber length and angle on ejector performance. CFD analysis can provide insights into flow characteristics to accurately optimize ejector geometry for a given application and reduce need for prototyping. The results of CFD analysis will be used to optimize ejector geometry to achieve better efficiency.
Design and Development of Valve Lapping MachineIRJET Journal
This document describes the design and development of a valve lapping machine. Valve lapping is an important process in internal combustion engine maintenance that is currently done manually using tools like lapping sticks, which are inefficient and time-consuming. The authors developed a mechanical valve lapping machine to automate the process and reduce human involvement. The machine employs two automated motions to replace the manual motions used in traditional lapping. This is expected to improve efficiency by reducing the time taken for valve lapping compared to existing manual methods. The goal of the project was to design an efficient and effective machine for automating the valve lapping process in internal combustion engine maintenance.
This chapter provides an introduction to basic accounting concepts for developers. It discusses the chart of accounts, which lists asset, liability, and equity accounts with their balances, and journals, which record business transactions and their impact on account balances. The key accounting equation of Assets = Liabilities + Owner's Equity is introduced, showing how the accounts must balance. Understanding these fundamental accounting terms and concepts will help developers communicate effectively with business clients.
This document provides an overview of steam engineering principles from Spirax Sarco, a manufacturer of steam system products. It defines key steam terms and concepts, explains how steam is formed through the boiling of water, and discusses steam generation in boilers. It also covers steam piping design, metering of steam and condensate, control of steam through valves and traps, and condensate management. The goal is to educate on the fundamentals of steam systems and efficient steam usage.
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Design and Development of a Low Cost Handheld Vacuum Cleanerijtsrd
A vacuum cleaner, like many other home products, is made to use it easier and more e icient for its customers to complete particular tasks. It must be effective at both collecting up dust particles and eliminating them from the air. This research paper develops a low cost effective vacuum cleaner and its parts. According to the literature review, the vacuum cleaner’s performance is mostly influenced by parameters including the impeller’s diameter, radius of curvature, strength, and speed. In this study, an unique impeller is designed with Creo, and the flow characteristics of the impeller are examined using CFD. The impeller’s thickness, form, and number of blades are all determined using the mechanical design process. In addition, polycarbonate was used as a material for making impeller in 3D printing. Dr. Velumani Subramaniam | Bhuvanesh Kumar V | Midun K | Mohanprasath G "Design and Development of a Low Cost Handheld Vacuum Cleaner" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-6 | Issue-7 , December 2022, URL: https://www.ijtsrd.com/papers/ijtsrd52404.pdf Paper URL: https://www.ijtsrd.com/engineering/mechanical-engineering/52404/design-and-development-of-a-low-cost-handheld-vacuum-cleaner/dr-velumani-subramaniam
IRJET-Split Casing Open Differential without Cross Pin and it’s Comparison wi...IRJET Journal
This document summarizes the design optimization of work roll chocks and backup roll chocks in a cold rolling mill. The current chocks were failing prematurely, resulting in production stoppages and costs. A 3D model of the chocks was created and analyzed using ANSYS software to determine stress distributions and critical areas under load. The design was iteratively optimized to reduce weight and material costs while maintaining structural integrity. The optimized design was found to reduce chock weight by over 10% and save $9,154.50 per chock based on material and production costs. Modal analysis confirmed the natural frequencies of the optimized design would not cause resonance issues. This new optimized chock design was concluded to provide improved life and cost
Paper cutting & rewinding machine project report SREESANGH P GHOSHSreesangh P Ghosh
The document provides details about the components of a paper cutting and rewinding machine. The main components are a rigid frame, four rollers mounted on plummer blocks with ball bearings to support rotation, a 1 Hp induction motor, a single V-belt and pulley system to transfer motion from the motor to one roller, a C-clamp cutter to cut paper, and nuts and bolts to assemble the components. The machine cuts paper and rewinds it onto rolls in a simple, compact design suitable for small industries.
Carbide Doctor Blades on Ceramic Press RollsKadant Inc.
Ceramic press rolls have become popular choices for improving papermaking efficiency and product quality. The proper selection and use of ceramic-tipped doctor blades and cleaning shower systems is critical in getting the highest performance from these rolls.
This document summarizes research on 3D printing hollow compounds of different shapes. It discusses how 3D printing allows for more optimized geometries compared to traditional manufacturing and can produce hollow turbine blades, gears, and disc brakes with properties similar to solid compounds. Finite element analysis was performed on hollow and solid shapes of different cross-sections, finding equivalent stresses were approximately the same. 3D printing reduces material costs and makes manufacturing hollow compounds easier compared to traditional methods. The document concludes 3D printing technologies provide design flexibility while creating parts with layer-by-layer printing instead of traditional manufacturing approaches.
Drive Power and Torque in Paper Machine DryersKadant Inc.
basic parameter in the design of a paper machine dryer drive system, whether it has an open gear, enclosed gear, or felt drive, is the drive power requirement. Previous work on the drive power for paper machine dryers covered a 1.5 meter diameter cylinder. This paper presents the results for both 1.5 and 1.83 meter diameter cylinders with and without dryer bars.
IRJET- Effect of Contaminated Oil on Temperature Variation of Tilting Pad...IRJET Journal
This document summarizes a study on the effect of contaminated oil on the temperature variation of tilting pad thrust bearings with bronze pads having a catenoidal surface profile. The study involved performing experiments on a test rig with 8 bronze pads under varying speeds, loads, and cooling flow rates. Temperature sensors were placed in a grid pattern over one of the pads to measure temperature changes at different locations. Results showed that adding contaminated powder to the lubricant caused fluid temperatures to increase more with higher thrust loads compared to using non-contaminated oil. The maximum temperature also shifted towards the trailing edge of the pad.
Need of Lapping Machine for Valve Component: A Case StudyIJMER
ABSTRACT: Lapping process is characterized by its low speed, low pressure, and low material removal rate. This process
is used in achieving finer surfaces and closer fits, correction of minor imperfections, and maintaining close tolerances.
During the process of lapping, the mechanisms of surface formation and removal rate are decisively influenced by
the movement type of the individual grains within the lapping abrasive. A gate valve is used to start and stop the flow of
fluid. So the wedge and seat ring of a valve are in continuous pressure of fluid flow and due to opening and closing of valve
these component get wear and they need lapping during reconditioning. This paper will share the need, requirement and
application of lapping during the reconditioning of valve.
This paper will explore the current working condition of lapping machine in valve industry. It will elaborate the
effect of abrasive particals, working speed, surface roughness and other related parameters. What are the difficulties they
are facing during the valve reconditioning related to lapping, will be disscussed.Current set up and the changes required in
this model are suggested with the proposed model.
Key words: Lapping process, wedge, seat ring, abrasive particles.
Design and Fabrication of advanced Abrasive flow machine for superfinishing m...IRJET Journal
This document describes the design and fabrication of an advanced abrasive flow machining (AFM) system for superfinishing machine parts. It discusses the key components of the AFM system including the machine, media, and tooling. The machine components like the piston assembly, media cylinders, fixtures, and hydraulic power pack are designed to operate at pressures up to 10 MPa. Formulas are provided for calculating dimensions of these components to withstand operating pressures. The document also summarizes the sequence of AFM operation and presents surface roughness results indicating the system is capable of achieving a final roughness of 0.120 microns on EN8 steel.
This document discusses optimizing cement grinding circuits through pre-crushing of clinker using a Barmac crusher prior to grinding in a two-compartment ball mill. Bond calculations and population balance modeling are used to analyze the potential benefits. Modeling suggests the total energy consumption for grinding can be reduced up to 10% by pre-crushing clinker to a finer size before ball milling. A case study of a cement plant found pre-crushing could lower the required ball mill power by 9-15% and increase grinding circuit capacity with relatively low capital investment compared to alternatives like high-pressure grinding rolls.
The document summarizes the tube hydroforming process used to form a complex exhaust duct part from thin-walled tube stock. A 400-ton press and custom hydroforming module were used to form the part by pressurizing water inside the tube against the contours of a split die set. Process parameters like pressure and feed rate had to be carefully controlled. The result was an 80% increase in circumference with only 9% wall thinning achieved in the part. Overall tube hydroforming was found to be an economical alternative to previous multi-piece welded construction of this type of part.
This document summarizes the design analysis and testing of an external gear pump developed to deliver 24.55 liters per minute of hydraulic oil. The gears and housing were designed based on available gear design standards and theories to meet the desired flow rate. Testing showed the pump achieved a maximum flow rate of 20 liters per minute with a volumetric efficiency of 81.47%. Flow rate decreased with increasing pressure at a rate of -0.344 liters per meter. The pump was fabricated locally from 0.4% carbon hot-rolled steel.
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- Tesla turbines use smooth disks instead of blades, relying on the viscosity and adhesion of fluid to rotate the disks. This makes them simpler and cheaper to produce than traditional bladed turbines.
- The researchers fabricated a Tesla turbine with disks containing variable depth dimples on the periphery to increase the boundary layer effect and cohesion of airflow.
- Testing showed disks with dimples rotated faster (13448 RPM) than smooth disks (12000 RPM) at a 5 bar inlet pressure, demonstrating increased efficiency from the dimple modifications.
The Rotosolver II is a high shear mixer developed by Admix to improve on their existing Rotosolver design. It delivers enhanced performance and efficiency through several design improvements:
1. It reduces energy consumption by up to 30% through streamlining and utilizing computational fluid dynamics software during development.
2. It improves dispersion by providing over 115% more mechanical high shear surface area and more than doubling the number of shearing edges.
3. It features an easy-to-clean design with an open mixing chamber to allow for thorough cleaning.
The document is a project seminar submitted by Mr. Rahul Raju Kundiya on the topic of experimental analysis and modelling in micro drilling of CFRP-Ti6Al4V stacked composite materials. It discusses micro drilling, the objectives of the study, experimental setup, design of experimentation, results and discussion. The study aims to design experiments to analyze the effect of drilling parameters on hole quality and develop a mechanistic force model. It presents results on hole taper, radial overcut, delamination factor and burr formation when drilling the composite material stack at different speeds and feed rates.
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High performance foil rotor improves de ink pulp screen
1. High Performance Foil Rotor Improves De-Ink Pulp Screening
James A. Olson, Cameron D. Pflueger1
, Sean Delfel, Carl Ollivier-Gooch, Pat Martin2
, Frederic Vaulot1
and Robert W. Gooding1
Department of Mechanical Engineering, Pulp and Paper Centre, University of British Columbia, Canada
1) Advanced Fiber Technologies, Montreal, Canada
2) Catalyst Paper, Paper Recycling Division, Coquitlam, Canada
ABSTRACT
Contaminant removal from waste paper remains a significant challenge for the recycle paper industry. This
challenge is expected to continue as the raw material quality decreases and the quality demands of the
papermaker and the printer increase. One of the most difficult contaminants to remove and the most
troubling for the papermaker and printer are adhesives ("stickies") that are readily deformable at
temperatures typically found in mill processes.
The primary stickies removal method is by screening with narrow slotted screen cylinders. The efficient
removal of stickies in the accept pulp requires optimization of the screen cylinder and rotor combination.
Because the sticky contaminants are deformable, the rotor must be designed to minimize the positive
pressure pulse which could force stickies through the slots. At the same time, the rotor must be designed to
have sufficiently strong negative pulses to ensure adequate capacity and runnability. The rotor should be
hydrodynamic and designed for low-speed operation to minimize power consumption.
A novel, dual element foil rotor has been developed to improve the stickies removal efficiency while using
significantly less power when compared to conventional rotors. The dual element foil rotor was designed
to have high capacity and to run reliably with very narrow, highly efficient, slotted cylinders. Foil shape
and orientation was optimized using Computational Fluid Dynamics (CFD). Superior rotor performance
was demonstrated in a mill trial. In summary, the dual element foil rotor was shown to have high stickies
removal efficiency, high capacity and excellent runnability while minimizing power consumption.
INTRODUCTION
Pressure screens are the most effective means of removing oversize contaminants, such as stickies and
shives, which reduce the strength, smoothness and optical properties of paper. Pressure screens are also
used to fractionate the pulp by fibre length allowing for the production of high-value products. For these
reasons, pressure screens are an increasingly important unit operation in pulping, recycling and
papermaking.
A pressure screen contains two main components: the screen cylinder and rotor. Once the unscreened pulp
enters the screen via the feed stream, the accept fibres pass through small slots or holes in the screen
cylinder to the accept stream, while oversized particles continue down the length of the cylinder to the
reject stream. The rotor uses a foil to which generates pressure pulses at the screen surface to backflush the
narrow slotted apertures clearing them of accumulations that could lead to plugging [1-4]. The rotor design
and speed thus directly affect the maximum capacity of the screen [5].
The pressure pulsations typically contain two components. There is a negative (or suction) component
which performs the backflushing action. One seeks to maximize this. There is also a positive component
which could cause stickies to be extruded and forced through the slot and into the accept stream [6]. One
seeks to minimize, or eliminate, the positive pressure pulse component.
Previous investigations into screen rotor design have shown that increasing the magnitude of the negative
pressure pulse generated by the rotor will increase the capacity of the screen [2]. The magnitude of the
negative pressure pulse is proportional to the square of the rotor tip speed [1-4]. Pilot studies have shown
that the maximum capacity of the screen increases approximately linearly with rotor tip speed [5]. The
2. power consumed by the rotor, however, increases with the cube of tip speed [7]. Therefore, small increases
in rotor tip speed can significantly increase power consumption and screen operating costs.
To improve the power-capacity relation of a screen rotor, several studies have examined the effect of rotor
foil design on the magnitude of the negative pressure pulse [1-3]. The "angle of attack" was identified as a
key parameter in rotor foil performance, and it is the angle formed between the chord of the foil and the
direction of the fluid, as shown in Figure 1. In a pulp screen, the general fluid flow is circumferential.
Thus the angle-of-attack is the angle of the foil chord relative to a line tangential to the cylinder.
Figure 1. Foil geometry
These fundamental studies showed that increasing the angle-of-attack of the foil would do two things: First,
it increases the magnitude of the negative pressure pulse generated by the foil prior to the point of flow
separation. Second, the undesirable positive pulse at the leading edge of the foil was eliminated. At higher
angles-of-attack, however, the foil would stall and the strength of the suction pulse would diminish.
Increasing the camber (i.e. the curvature) of the foil was also shown to increase the strength and width of
the negative pressure pulse generated by the rotor. The high camber foils where found, however, to stall
almost immediately at a very small angle-of-attack. In order to obtain the effect of a highly cambered foil
at a high angle-of-attack, dual element foil (DEF) technology was developed for a pulp screen [8]. Similar
to the flaps on an aircraft, dual element airfoils allow higher energy flow from the lower surface of the foil
to pass through the slot between the main foil and the flap in order to re-energize the boundary layer on the
upper surface of the foil. This has the effect of preventing stall on the foil, allowing for higher magnitude
negative pulses at a given rotor tip speed, while at the same time eliminating the positive pulse component.
Figure 2 shows the pressure contours for single and dual element foils and how a stronger and wider
pressure pulse is generated by the DEF configuration.
The main parameters of pulp screen performance are: capacity, debris removal efficiency and power
consumption. Capacity is the mass flow of pulp in the accept stream of the screen. Debris removal
efficiency reflects the ability of the screen to direct oversize debris from the feed to the reject stream.
Power is best expressed as the net power to the screen (excluding winding losses), but is most commonly
given as the total power, as shown on the Distributed Control System (DCS) in a pulp mill. The goal in
designing high-performance rotors is to improve on one of the performance parameters without
compromising the others. This study examines the results from a prototype DEF rotor in a mill study
which meets this goal.
3. Figure 2. The computed fluid streamlines and pressure contours for a single foil (left) and a dual element
foil (right)
MILL APPLICATION
The design of the DEF rotor was evaluated using computational fluid dynamics (CFD). CFD has been
validated for use as a tool in pressure screen rotor design in a number of studies. In the case of the DEF
rotor, a second-order finite volume solver, FLUENT 6.1, was used to numerically solve the discretized
Navier-Stokes equations. Following the results in Mahon and Zhang [9], the k-ε model with enhanced wall
treatments was used to model the turbulence in the flow.
A commercial, high-cambered foil rotor was used as a starting point for the new foil design [4-5]. A wide
range of foil parameters were studied, including the foil angle-of-attack, the flap angle, and the positioning
of the flap with respect to the main foil. Figure 3 shows the effect of varying the angle-of-attack (alpha)
and the flap angle (delta) of the foil on the streamlines and pressure field. Increasing both flap angle and
angle-of-attack eliminates the positive pressure pulse at the leading edge and increases the strength of the
negative pulse prior to stall. Figure 3 also shows that the maximum suction pulse is achieved with an
angle-of-attack of 3 degrees, and a flap angle of 19 degrees. As the angles are further increased, the
negative pulse begins to decrease as the dual element foil begins to stall. After a thorough analysis, optimal
foil angles were chosen and a mill prototype was built by Advanced Fiber Technologies, as shown in
Figure 4.
Figure 3. Pressure traces and contours for varying degrees of foil angle-of-attack (alpha), and flap angle
(delta) of the dual element foils
4. Figure 4. The optimized DEF design (left) and the mill-scale prototype rotor (right) installed at Catalyst
Paper Recycling Division.
The mill scale prototype rotor was installed in a fully-instrumented GR20 primary fine screen at the
Catalyst Paper, Paper Recycling Division, de-ink pulp mill in Coquitlam, British Columbia, Canada. The
rotor was evaluated in parallel to an OEM screen, offering an easy comparison to the current OEM rotor
technology. Identical wedgewire cylinders with 0.15 mm (0.006”) slots were installed in both screens. The
OEM rotor was operated at a tip speed of 16 m/s (60 Hz). Figure 5 shows the flow diagram of the recycle
mill.
Figure 5. Catalyst Paper, Paper Recycling Division Flowsheet
A variable frequency drive was used to optimize the rotor speed and evaluate the effect of tip speed on
performance in terms of power consumption, stickies removal efficiency, and capacity. For the period of
the trial, the screens were run at the mill's normal operating conditions: a reject rate of 22.5% (by mass),
feed consistency between 1.1 and 1.3%, and slot velocity of 1.3 m/s.
5. RESULTS
Power consumption for the DEF rotor is shown in Figure 6 as a function of rotor tip speed. Rotor speed
was decreased from 16 m/s to a minimum operating speed of 11.2 m/s where the screen plugged. Note that
the existing speed of the OEM rotor (of 16 m/s) was based on the OEM's own optimization work at this
mill and the mill's finding that the OEM screen would plug at a rotor tip speed of 15 m/s. Differential
pressure (i.e. the feed minus the accept pressure) was monitored as an indication of the stability of the
screen. Pulp samples were taken at various rotor speeds to evaluate reject thickening. Reject thickening is
the reject consistency divided by the feed consistency. High reject thickening can be a precursor of
runnability problems. A stable operating set point was determined to be 13.3 m/s while maintaining
capacity, which provided power savings of 42% compared to the parallel screen with the OEM rotor
10
15
20
25
30
35
40
45
50
55
11 12 13 14 15 16 17
Tip Speed (m/s)
Power
(kW)
DEF Rotor
OEM Rotor
42%
Figure 6. Screen power consumption versus rotor tip speed. Power savings of approximately 42% were
obtained compared to the parallel OEM screen. Runnability remained excellent and there was no decrease
in operating capacity.
Thickening factor is shown in Figure 7 as a function of rotor tip speed. The lower thickening factor of the
DEF rotor relative to the OEM rotor at equivalent rotor speeds of 16 m/s suggests that the DEF rotor has
better runnability and potentially higher capacity. Thickening factor increased as tip speed was reduced.
The volumetric reject rate was maintained constant during the trial period (at 14%), thus reject rate (by
mass) increased from 19% to 24% as tip speed was reduced. The tip speed of the DEF rotor could be
reduced to 13.3 m/s, while maintaining a thickening factor which was approximately equivalent to the
existing OEM rotor operating at a speed of 16 m/s.
Stickies efficiency was higher with the DEF rotor than the OEM rotor, as shown in Figure 8, when operated
in the same screen model, same cylinder, same passing velocity, same tip speed and same mass reject rate
(of 22.5%). A common mass reject rate was obtained by applying a correction factor based on a plug-flow
model of screen performance. The data point for the OEM rotor represents an average of 18 measurements
taken over time by mill staff. Further increases in stickies removal efficiency were obtained as the rotor tip
speed was reduced. These effects are consistent with the discussion of the fundamental principles of the
6. DEF rotor, which anticipates an increase in stickies removal efficiency due to reduction of a positive
component of the pressure – both through rotor design and reduced rotor speed.
1.0
1.2
1.4
1.6
1.8
2.0
12 13 14 15 16 17
Tip Speed (m/s)
Thickening
Factor
DEF Rotor
OEM Rotor
Figure 7. Thickening factor versus rotor tip speed
40%
50%
60%
70%
80%
12 13 14 15 16 17
Tip Speed (m/s)
Stickies
Removal
Efficiency
DEF Rotor
OEM Rotor
Figure 8. The DEF rotor provided a higher stickies removal efficiency than the OEM rotor. Further
increases in efficiency were obtained as rotor speed was decreased.
7. Stickies removal efficiency was, in fact, determined by using two macro stickies analysis methods. The
method used by Catalyst Paper determined the stickies removal efficiency by count. This mill-specific
method used a Pulmac screen with 0.15 mm slots to isolate the stickies, followed by a manual count using a
microscope. An independent laboratory (CIPP) confirmed the results by measuring the stickies removal
efficiency, also using a Pulmac screen with 0.15 mm slots to isolate the specks, but then identifying the
stickies through a dying technique, followed by manual verification. Image analysis was used to assess the
number and size of the stickies [10].
Samples for the CIPP analysis were taken from both parallel screens while the DEF rotor was operating at
the reduced tip speed of 13.3 m/s and the OEM rotor was running at 16 m/s. The results shown in Figure 9
confirm the stickies removal efficiency of the dual element foil rotor is higher than the OEM rotor when
measuring efficiency either by count or by area (mm2
/g of oven dried pulp). Efficiencies for both the OEM
and DEF rotors are slightly higher in Figure 9 than in Figure 8, which is a reflection of the day-to-day
variability in the character of the stickies and the efficiency measurements. Figure 10 shows the stickies
particle distribution from the accept streams of both parallel screens. The substantially higher amount of
small stickies in the 0.21 mm2
size class suggests that the OEM rotor may have been fragmenting the
stickies into smaller particles which would have contributed to the lower efficiency of the OEM screen and
higher stickies count in the accepts.
The good runnability of the DEF rotor should also be noted. The DEF rotor evaluation was made over a 3
week period. The rotor operated reliably throughout this trial period. There was no stringing or any
accumulation of pulp or contaminants on the rotor or in the gap between the foil and flap, as shown in
Figure 11.
0%
20%
40%
60%
80%
100%
1 2
Stickies
Removal
Efficiency
OEM Rotor
DEF Rotor
Area
Count
Figure 9. Stickies removal efficiency measurements by count and area with equivalent 0.15 mm (0.006”)
wedgewire cylinders and a reject rate of 22.5% by mass
.
8. 0
1
2
3
4
5
6
7
8
0.21 0.3 0.4 0.5 0.75 1 1.5 2 2.5 3
Stickies Distribution (mm
2
)
Accept
Stickies
Concentration
(number
per
gram)
OEM Rotor
DEF Rotor
<
Figure 10. Stickies Distribution (mm2
)
Figure 11. DEF rotor at the end of the trial period. The pulp shown in this photo was deposited during
drainage of the pulp screen and was easily washed away. There was no accumulation or plugging between
the foil and flap.
9. CONCLUSION
A new patented rotor technology has been developed to increases the strength and duration of rotor
pulsations without producing undesirable, positive pulse components. A prototype DEF rotor was tested in
the GR20 primary fine screen at the Catalyst Paper mill in Coquitlam, British Columbia. The DEF rotor
was able to maintain the full required capacity of the screen even when operated at a top speed of 13.3 m/s
-- relative to the usual operating speed of 16 m/s. An energy saving of 42% was achieved by operating the
screen at this lower speed.
The thickening factor of the DEF rotor is lower than the OEM rotor at equivalent tip speeds. The stickies
removal efficiency of the DEF rotor was higher than the OEM rotor and further increases in efficiency were
obtained as the DEF rotor speed was decreased. The DEF rotor was shown to operate reliably and without
plugging or stringing during the three week duration of the trial.
The excellent results of this trial follow on the fundamental benefits of the DEF rotor design. While a high
degree of foil camber will provide a wider and stronger pulse, traditional, single-piece foils are limited in
camber because of the occurrence of phenomenon called "boundary layer separation". The DEF rotor uses
its unique design to avoid boundary layer separation. Lower tip speeds are thus possible without
compromising the action of the rotor or capacity of the screen. Substantial power savings result. In
addition, the lower speed of the rotor would appear to avoid fragmentation of the stickies. Efficiency is
further increased because the rotor pulse can be optimized to eliminate the positive pressure component
which would tend to force deformable contaminants such as stickies through the screen apertures. This
study has thus confirmed the efficacy of the DEF rotor design and demonstrated its practicality in a mill
environment.
REFERENCES
1. Feng, M., “Numerical simulation of the pressure pulses produced by a pressure screen foil rotor”, M. A.
Sc. Thesis, Dept. Mech. Eng., Univ. British Columbia, 2003.
2. Feng, M., Olson J.A., Ollivier-Gooch, C.F., Xia J., and Gooding, R.W., “A computational fluid dynamic
(CFD) tool for advanced pulp screen foil rotor design” ABTCP Conf., San Paulo, Brazil, Oct. 2003.
3. Feng, M., Gonzalez J., Olson, J.A., Ollivier-Gooch, C., and Gooding, R.W., “Numerical simulation of
the pressure pulses produced by a pressure screen foil rotor”, J. Fluid Eng. 127(2):347-357 (2005).
4. Gonzalez, J.A., “Characterization of design parameters for a free foil rotor in a pressure screen”, M. A.
Sc. Thesis, Dept. Mech. Eng., Univ. British Columbia, 2002.
5. Pflueger, C.D., Olson, J.A., and Gooding, R.W., “The performance of the EP Rotor in de-ink pulp
screening”, Preprints 2007 Appita Conf., 8 p.
6. Julien Saint Amand, F., Perrin, B., Gooding, R., Huovinen, A., Asendrych, D., and Favre-Marinet, M.,
“Optimisation of screen plate design for the removal of stickies from deinking pulps”, PTS-Deinking
Symposium, 2004
7. Olson, J.A., Turcotte, S., and Gooding, R.W., “Determination of power requirements for solid core pulp
screen rotors”, Nordic Pulp and Paper Res. J. 19(2):213-217 (2004).
8. Olson, J.A., and Ko, J., “Multi-Element Airfoil for Pulp Screens”, U.S. Patent No. 6,883,669, Apr. 26,
2005.
9. Mahon, S., and Zhang, X., "Computational analysis of pressure and wake characteristics of an aerofoil in
ground effect", J. Fluids Eng., 127(3): 290-298 (2005).
10. "Macro stickies content in pulp", Laboratory Procedure PL-140, Centre Integre en Pates et Papiers
(CIPP), Trois-Rivieres Quebec (April 04, 2002).