The Processing of Filler-Reinforced Rubber

1977 ◽  
Vol 50 (4) ◽  
pp. 765-779 ◽  
Author(s):  
E. S. Dizon ◽  
L. A. Papazian
Keyword(s):  
Carbon Black ◽  
Total Energy ◽  
Flow Rate ◽  
Mixing Time ◽  
Flow Characteristics ◽  
Maximum Flow ◽  
Quality Level ◽  
Processing Unit ◽  
Specific Flow ◽  
Mixing Energy

Abstract Further insight into the mixing process has allowed a definition of the intermediate objectives of processing, which relate to the different transformations that occur as mixing energy is added to a rubber formulation. These convert the ingredients into a coherent mass with specific flow characteristics and determine the efficiency of the next unit, therefore contributing to overall productivity. The total energy added to the batch is derived from a combination of Banbury, mill, and extruder. These processing units vary in the efficiency with which they achieve the required material transformations. Proper allocation of mixing energy to the most effective equipment, with a knowledge of the total energy required to achieve the desired quality, allows a rational optimization of productivity and product quality. Operating profiles for each unit have been constructed in order to aid in optimizing the process. Using a fixed total energy input, these profiles were used to estimate the productivity of each processing unit. The study shows that in a semicontinuous operation with laboratory-size Banbury, mill, and extruder, the extruder is the primary determinant of overall productivity. The study also shows that maximizing productivity in a single unit will not necessarily lead to the highest productivity along the equipment train. Material properties affect overall productivity in several ways. In this work, carbon black surface area determined the total energy required to attain the desired quality level, the flow rate in the extruder, and the energy required to attain the maximum flow rate. Future studies should focus on the derivation of operating equations for specific equipment and materials. These equations should quantify the interrelationships between the different engineering parameters (such as screw or rotor speeds and Banbury ram pressure), the processing parameters (such as mixing time, fill factor, and temperature), and material variables (such as Mooney viscosity, carbon black morphology, and black and oil loading).

scholarly journals Determination of receiver consumption characteristics using computer simulation

2020 ◽  
Vol 8 (2) ◽  
pp. 10-14
Author(s):  
S.S. Vasyliv ◽  
◽  
V.S. Zhdanov ◽  
M.V. Yevseyenko ◽  
◽  
...  
Keyword(s):  
Computer Simulation ◽  
Flow Rate ◽  
Rocket Engine ◽  
Flow Characteristics ◽  
Maximum Flow ◽  
Complex Configuration ◽  
Rocket Engines ◽  
Gas Leakage ◽  
Control Forces ◽  
Firing Tests

The problem of implementing the detonation mode of fuel combustion in thermal propulsion systems has been widely studied last decade. There are many works on fundamental and applied research on pulsating detonation. Solid propellant detonation engines can develop significant forces for a short time at low structural masses, and therefore they are ideal for auxiliary systems for the removal of separated rocket parts. In addition, detonation processes can be used to create control forces for correcting the trajectory of aircraft. All these facts determine the relevance of the area of work. For studying detonation installations, it is necessary to create test stands, but the design of test installations is an urgent and complex optimization problem. It is advisable to solve this problem with the help of computer simulation. In the existing experimental methods, for designing, it is necessary to determine in advance the geometric parameters of receivers and pipelines that provide the necessary gas consumption for firing tests of detonation rocket engines. The work is devoted to the development of a method for determining the flow characteristics of a receiver with a pipeline of complex configuration based on the constructed model of the stand. Based on the initial data, a computer simulation of the air leakage process from the receiver was carried out, for which the Solid Works software package was used. The places of pressure drop, maximum flow rate, and air mass flow are determined. The low value of the flow rate factor is due to the complex configuration of the pipeline with numerous bends and two bellows. Comparison of calculation results with experimental data was held. The difference between the experimental and calculated values does not exceed 3.6%. The obtained information is used to select the required value of the oxidizer excess coefficient during firing tests of detonation rocket engine models. Keywords: flow rate, gas leakage, receiver, model.

The Fabrication and Test of a Phase-Change Micropump

2001 ◽  
Author(s):  
Hyeun Joong Yoon ◽  
Woo Young Sim ◽  
Sang Sik Yang
Keyword(s):  
Phase Change ◽  
Flow Rate ◽  
Flow Characteristics ◽  
Check Valve ◽  
Maximum Flow ◽  
Input Voltage ◽  
Working Fluid ◽  
Duty Ratio ◽  
Boron Diffusion ◽  
Change Type

Abstract This paper presents the fabrication and test of a phase-change type micropump with two aluminum flap valves. This micropump consists of a pair of Al flap valves and a phase-change type actuator. The actuator is composed of a heater, a silicone rubber diaphragm and a working fluid chamber. The diaphragm is actuated by the vaporization and the condensation of the working fluid. The micropump is fabricated by the anisotropic etching, the boron diffusion and the metal evaporation. The dimension of the micropump is 8.5 mm × 5 mm × 1.7 mm. The forward and the backward flow characteristics of the flap valve illustrate the appropriateness as a check valve. Also, the flow rate of the micropump is measured. When the square wave input voltage of 10 V is applied to the heater, the maximum flow rate of the micropump is 6.1 μl/min at 0.5 Hz and the duty ratio of 60% for zero pressure difference.

scholarly journals Development of a Design Tool for Flow Rate Optimization in the Tata Swach Water Filter

2014 ◽  
Author(s):  
Sean T. Ricks ◽  
John R. Lewandowski ◽  
Emmanuel G. Lim ◽  
Dawn M. Wendell ◽  
Amos G. Winter
Keyword(s):  
Flow Rate ◽  
Flow Behavior ◽  
Flow Characteristics ◽  
Maximum Flow ◽  
Primary Objective ◽  
Design Tool ◽  
Water Filter ◽  
Increase Flow Rate ◽  
Weak Points ◽  
Rate Optimization

When developing a first-generation product, an iterative approach often yields the shortest time-to-market. In order to optimize its performance, however, a fundamental understanding of the theory governing its operation becomes necessary. This paper details the optimization of the Tata Swach, a consumer water purifier produced for India. The primary objective of the work was to increase flow rate while considering other factors such as cost, manufacturability, and efficacy. A mathematical model of the flow characteristics through the filter was developed. Based on this model, a design tool was created to allow designers to predict flow behavior without prototyping, significantly reducing the necessity of iteration. Sensitivity analysis was used to identify simple ways to increase flow rate as well as potential weak points in the design. Finally, it was demonstrated that maximum flow rate can be increased by 50% by increasing the diameter of a flow-restricting feature while simultaneously increasing the length of the active purification zone. This can be accomplished without significantly affecting cost, manufacturability, and efficacy.

A prototype paediatric venous cannula with shape change in situ

Perfusion ◽  
2003 ◽  
Vol 18 (1) ◽  
pp. 61-65 ◽  
Author(s):  
David Jegger ◽  
Antonio F Corno ◽  
Antonio Mucciolo ◽  
Giuseppe Mucciolo ◽  
Yves Boone ◽  
...  
Keyword(s):  
Flow Rate ◽  
Shape Change ◽  
Venous Pressure ◽  
Flow Characteristics ◽  
Maximum Flow ◽  
Venous Drainage ◽  
Vessel Diameter ◽  
Single Stage ◽  
Set Up

During cardiopulmonary bypass (CPB), venous drainage may be impeded due to small vessel and cannula size or chattering, thus, blood return to the heart-lung machine is reduced. We designed a self-expandable prototype cannula, which is able to maintain the vein open and overcome this problem and analysed its performance capability. This prototype and several other cannulae were tested using an access vessel diameter of 7 mm. An in vitro circuit was set up with a 10 mm penrose latex tube simulating the patient’s vein placed between the patient preload reservoir and the cannula, encasing the cannula’s inlet(s). Maximum flow rate was determined for passive venous drainage (PVD) at preloads (P) of 2 and 4 mmHg. We compared these results to three classic single-stage venous cannulae: basket tip, thoracic drain and percutaneous tip. By comparing the other cannulae to the prototype, under PVD conditions and a central venous pressure (CVP) of 2 mmHg, the prototype cannula’s flow rate (1.329 /0.04 L/min) outperformed the basket type (the best performing comparator) (1.029 /0.08 L/min) by 23% (p B /0.005). When the preload was increased to 4 mmHg under PVD conditions, the same trend was noted with the prototype cannula (1.659 /0.05 L/min), outperforming the basket cannula’s value (1.269 /0.05 L/min) by 24% (p B /0.001). This new cannula design provides superior flow characteristics, under all test conditions, compared to the classic single-stage venous cannulae used for paediatric CPB surgery.

Piezo-Actuated Valveless Micropumps for Micro-Total Analysis Systems

2010 ◽  
Author(s):  
Arvind Chandrasekaran ◽  
Muthukumaran Packirisamy
Keyword(s):  
Flow Rate ◽  
Glass Substrate ◽  
Flow Characteristics ◽  
Low Frequency ◽  
Lab On A Chip ◽  
Maximum Flow ◽  
Valveless Micropump ◽  
Chip Flow ◽  
Micro Total Analysis Systems ◽  
Total Analysis

In this work, a Piezo actuated Valveless micropump is proposed for applications in Micro-Total Analysis Systems (μTAS) and Lab-on-a-Chip. Flow rectification in the micropump has been brought about with the use of a diffuser element. The device is fabricated on PDMS-Glass substrate with the glass acting as the diaphragm. A PZT disc is integrated with the setup for actuation. The micropump has been characterized for its dynamic behavior, flow characteristics, and pressure. It was found that the maximum flow rate for the micropump was obtained at low frequency which makes it usable for practical μTAS applications.

Flow Maldistribution in Multichanneled Microdevices With In-Line Manifolds

2009 ◽  
Author(s):  
J. Soman ◽  
B. Mathew ◽  
T. J. John ◽  
H. Hegab
Keyword(s):  
Fluid Flow ◽  
Microfluidic Device ◽  
Flow Rate ◽  
Flow Characteristics ◽  
Flow Distribution ◽  
Simulation Software ◽  
Channel Width ◽  
Computational Time ◽  
Specific Flow ◽  
The Difference

This paper deals with the analyses of fluid flow distribution in a microfluidic device with in-line manifolds. The analysis was performed using commercially available microfluidic simulation software called CoventorWare™. The number of channels in the microfluidic device considered for this study was kept at ten due to limitations on the number of nodes and computational time. Channels with only square profile were analyzed for flow rates varying between 1 to 60 ml/min. The length of the channels was maintained at 1.5 cm for all simulations. The fluid flow distribution characteristics for different channel widths/depths (200, 100, and 75 μm) were investigated. It was observed that the flow rate decreased from the central channels to the outer channels. The flow per channel was symmetric about the geometric centre of the microdevice. The uniformity in flow was accessed using the root mean square value of flow per channel and it decreased with decrease in channel width/depth for a specific flow rate. The difference in the flow rate through the channels increased with increase in total flow rate. Similarly, the spacing between the channels was varied (300, 200, and 100 μm) for a microdevice with channel width/depth of 100 μm and its corresponding flow characteristics were studied for flow rate ranging between 1 ml/min and 60 ml/min. Finally, the length of each manifold was varied between 2500 μm and 1000 μm for understanding the effect of manifold length on flow distribution. The standard deviation of flow per channel did not show much variation with changes in spacing and manifold length. In addition each design of the manifolds was analyzed on the basis of pressure and flow rate as well as velocity profile in each of the channels.

Scaling of Flow Characteristics and Power Consumption With Profile Height for Miniature Centrifugal Fans

2007 ◽  
Author(s):  
P. A. Walsh ◽  
V. Egan ◽  
R. Grimes ◽  
E. Walsh
Keyword(s):  
Aspect Ratio ◽  
Power Consumption ◽  
Flow Rate ◽  
Scaling Laws ◽  
Flow Characteristics ◽  
Pressure Rise ◽  
Maximum Flow ◽  
Aspect Ratios ◽  
Low Profile ◽  
Centrifugal Fans

This paper addresses issues that relate to downscaling the height of centrifugal fans for application in low profile technologies, such as the cooling of portable power electronics. The parameters studied throughout the paper include flow rate, pressure rise and power consumption characteristics. The former two of these are measured using a fan characterization rig and the latter by directly measuring the power supplied to the fan. These are studied for fans ranging in diameter from 15 to 30mm and with profile heights ranging from 0.3mm to 15mm. It is found that all of the phenomena encountered are best described in terms of fan aspect ratio. Overall, the results show that the conventional scaling laws cannot be accurately applied when the blade profile alone is being scaled. Indeed the only parameter that was observed to be accurately predicted by the scaling laws was the pressure rise attainable but was only accurate for fan aspect ratios greater than 0.17. Below this, the measured pressure rise characteristics fell logarithmically toward zero. The results also showed that there is no advantage to using fans with aspect ratio greater than 0.3. This was because the maximum flow rate was achieved at this aspect ratio and decreased slightly as it was further increased. Overall, the scaling phenomena described throughout this paper are invaluable to designer of efficient low profile cooling solutions that are to incorporate such fans.

scholarly journals Physical Simulation on Molten Steel Flow Characteristics of RH Vacuum Chamber with Arched Snorkels

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Zhi-Feng Ren ◽  
Zhi-Guo Luo ◽  
Fan-Xia Meng ◽  
Zong-Shu Zou ◽  
Yi-Hong Li ◽  
...  
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Vacuum Chamber ◽  
Physical Simulation ◽  
Mixing Time ◽  
Flow Characteristics ◽  
Circulation Flow ◽  
Cross Sectional ◽  
Refining Efficiency ◽  
Circulation Flow Rate

The RH vacuum refining technology is a vitally powerful method of producing clean steel. The inner diameter of traditional circular snorkel is very difficult to be increased owing to the metallurgical refractory thickness around the snorkels and the limitation of the area under the vacuum chamber, limiting the increase in refining efficiency. In order to improve the refining efficiency of the RH reactor, a new designed RH degasser with an optimized arched snorkel is established. This design replaces the traditional two circular snorkels structure with the two arched snorkels and greatly enhances the cross-sectional area of snorkel. In this study, the flow characteristics of this new type RH were studied and analyzed by establishing a 1 : 5.5 physical model of RH with arched snorkels. Results show that the circulation flow rate of RH with arched snorkels can increase by 100% ∼ 180% and the mixing time approximately decreases by 35% compared with RH with circular snorkels under actual production conditions. The circulation flow rate of RH with arched snorkels continues to increase obviously when gas flow rate exceeds the saturated value of RH with circular snorkels. The RH with arched snorkels can increase the refining efficiency significantly and has important application prospect.

scholarly journals Differential equations for calculating gas exchange in an internal combustion engine

2021 ◽  
Vol 264 ◽  
pp. 01003
Author(s):  
Zakirjon Musabekov ◽  
Jamshid Khakimov ◽  
Ergashev Botir
Keyword(s):  
Pressure Drop ◽  
Gas Exchange ◽  
Internal Combustion Engine ◽  
Flow Rate ◽  
Combustion Engine ◽  
Flow Characteristics ◽  
Maximum Flow ◽  
Internal Combustion ◽  
Dimensional Model ◽  
Short Period

Considering the unsteadiness of the flow in the valve channels and windows of the internal combustion engine in combination with limiting the maximum flow rate allows you to take into account the flow characteristics in the exhaust systems of forced engines. Thus, the calculation according to the above method allows us to obtain by calculation, observed in experiments, the reverse pressure drop in the short period of the end of the free release, the validity of using a modified 0-dimensional model of gas exchange, even for engines with long manifolds, where the Strophe number is less than 8.

Outcome of Buccal Mucosal Graft Urethroplasty in Long Segment Anterior Urethral Stricture

2020 ◽  
Vol 19 (2) ◽  
pp. 64-68
Author(s):  
Mrinmoy Biswas ◽  
Sudip Das Gupta ◽  
Mohammed Mizanur Rahman ◽  
Sharif Mohammad Wasimuddin
Keyword(s):  
Urethral Stricture ◽  
Flow Rate ◽  
Surgical Outcome ◽  
Simple Technique ◽  
Anterior Segment ◽  
Maximum Flow ◽  
Anastomotic Site ◽  
Buccal Mucosal Graft ◽  
Male Patients

Objective: To assess the success of BMG urethroplasty in long segment anterior urethral stricture. Method: From January 2014 to December 2015, twenty male patients with long anterior segment urethral stricture were managed by BMG urethroplasty. After voiding trial they were followed up at 3 month with Uroflowmetry, RGU & MCU and PVR measurement by USG. Patients were further followed up with Uroflowmetry and PVR at 6 months interval.Successful outcome was defined as normal voiding with a maximum flow rate >15ml /sec and PVR<50 ml with consideration of maximum one attempt of OIU after catheter removal. Results: Mean stricture length was 5.2 cm (range 3-9 cm) and mean follow-up was 15.55 months (range 6-23 months). Only two patients developed stricture at proximal anastomotic site during follow-up. One of them voided normally after single attempt of OIU. Other one required second attempt of OIU and was considered as failure (5%). Conclusion: BMG urethroplasty is a simple technique with good surgical outcome. Bangladesh Journal of Urology, Vol. 19, No. 2, July 2016 p.64-68

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