scholarly journals New universal inlet chamber for vertical and horizontal spindle cotton pickers

2021 ◽  
Vol 1889 (4) ◽  
pp. 042006
Author(s):  
R D Matchanov ◽  
A A Rizaev ◽  
A T Yuldashev ◽  
D A Kuldoshev ◽  
M M Mirzaeva
Keyword(s):  
Inlet Chamber

scholarly journals Numerical study of a double inlet chamber counter flow vortex tube with insulation

2021 ◽  
Vol 850 (1) ◽  
pp. 012024
Author(s):  
Ravi Kant Singh ◽  
Achintya Kumar Pramanick ◽  
Subhas Chandra Rana
Keyword(s):  
Vortex Tube ◽  
Numerical Study ◽  
Working Fluid ◽  
Turbulent Model ◽  
Counter Flow ◽  
Fluent Software ◽  
Exit Temperature ◽  
Flow Vortex ◽  
Inlet Chamber ◽  
Double Chamber

Abstract The present study intends to improve the performance of the Ranque-Hilsch counter flow vortex tube, analysed using computational fluid dynamics. In the axisymmetric 3-D, steady-state, compressible, and turbulent flow vortex tube, the air has been used as the working fluid. The ANSYS17.1 FLUENT software has been used with the standard º-ε turbulent model for different mass fraction of cold fluid and inlet pressure in the numerical simulation and validated with the experimental results. It is observed from the study that as the inlet chambers number increases from 1 to 2, there is a decrease of 7.8 % in the cold exit temperature of the vortex tube. However, insulating the double chamber vortex tube leads to a further reduction of 4.2% in the cold exit temperature. Therefore, it indicates that the overall decline in the cold exit temperature from one chamber non-insulated vortex tube to double chamber insulated vortex tube is 9.6%. In terms of cold exit temperature, it can be concluded that using a double inlet chamber vortex tube with insulation yields the optimum results.

Load-Force-Adaptive Outlet Throttling: An Easily Commissionable Independent Metering Control Strategy

2016 ◽  
Author(s):  
Jan Lübbert ◽  
André Sitte ◽  
Benjamin Beck ◽  
Jürgen Weber
Keyword(s):  
Hydraulic System ◽  
Control Algorithm ◽  
Systematic Approach ◽  
Load Force ◽  
Chamber Pressure ◽  
The Novel ◽  
Test Rig ◽  
Mechanical Pressure ◽  
And Control ◽  
Inlet Chamber

This paper deals with a novel independent metering valve system which is intended to be used in medium sized mobile machines. The system uses a mechanical pressure compensator to enable a very simple SISO control algorithm which does not need any feedback parameters to be adjusted. The algorithm is capable of handling resistive and pulling loads at a certain desired velocity and inlet chamber pressure level. The paper gives a brief summary of the systematic approach to deriving the valves structure and compares different control approaches for the complete hydraulic system comprising several actuators. Special emphasis is given to the preferred solution, which is verified on a laboratory test rig consisting of reasonably priced mobile machine components. Furthermore a linear model of system and control structure is constructed to give detailed information regarding the dynamic characteristics of the controlled drive. The energetic benefits of the novel system architecture in comparison to a standard coupled metering flow sharing system are investigated by means of a levelling movement performed on the test rig and a simulated synthetic high power digging cycle.

Air/Water Counter-Current Flow Experiments in a Model of the Hot Leg of a Pressurized Water Reactor

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Christophe Vallée ◽  
Deendarlianto ◽  
Matthias Beyer ◽  
Dirk Lucas ◽  
Helmar Carl
Keyword(s):  
Steam Generator ◽  
Pressure Vessel ◽  
Test Section ◽  
Current Flow ◽  
Flow Limitation ◽  
Two Phase ◽  
Pressurized Water ◽  
Counter Current Flow ◽  
Counter Current ◽  
Inlet Chamber

Different scenarios of small break loss of coolant accident for pressurized water reactors (PWRs) lead to the reflux-condenser mode in which steam enters the hot leg from the reactor pressure vessel (RPV) and condenses in the steam generator. A limitation of the condensate backflow toward the RPV by the steam flowing in counter current could affect the core cooling and must be prevented. The simulation of counter-current flow limitation conditions, which is dominated by 3D effects, requires the use of a computational fluid dynamics (CFD) approach. These numerical methods are not yet mature, so dedicated experimental data are needed for validation purposes. In order to investigate the two-phase flow behavior in a complex reactor-typical geometry and to supply suitable data for CFD code validation, the “hot leg model” was built at Forschungszentrum Dresden-Rossendorf (FZD). This setup is devoted to optical measurement techniques, and therefore, a flat test-section design was chosen with a width of 50 mm. The test section outlines represent the hot leg of a German Konvoi PWR at a scale of 1:3 (i.e., 250 mm channel height). The test section is mounted between two separators, one simulating the RPV and the other is connected to the steam generator inlet chamber. The hot leg model is operated under pressure equilibrium in the pressure vessel of the TOPFLOW facility of FZD. The air/water experiments presented in this article focus on the flow structure observed in the region of the riser and of the steam generator inlet chamber at room temperature and pressures up to 3 bar. The performed high-speed observations show the evolution of the stratified interface and the distribution of the two-phase mixture (droplets and bubbles). The counter-current flow limitation was quantified using the variation in the water levels measured in the separators. A confrontation with the images indicates that the initiation of flooding coincides with the reversal of the flow in the horizontal part of the hot leg. Afterward, bigger waves are generated, which develop to slugs. Furthermore, the flooding points obtained from the experiments were compared with empirical correlations available in literature. A good overall agreement was obtained, while the zero penetration was found at lower values of the gaseous Wallis parameter compared with previous work. This deviation can be attributed to the rectangular cross section of the hot leg model.

Observation of Flow in a Ring Inlet Chamber

1979 ◽  
Vol 101 (1) ◽  
pp. 135-142 ◽  
Author(s):  
P. Merkli ◽  
M. P. Escudier
Keyword(s):  
Critical Reynolds Number ◽  
Axial Flow ◽  
Reynolds Numbers ◽  
Symmetric Flow ◽  
Exit Tube ◽  
Quantitative Measurements ◽  
Flow Situation ◽  
Strong Vortex ◽  
Inlet Chamber ◽  
Center Body

We present the results of visualization and quantitative measurements of the flow in a simplified model ring chamber of the type used in axial-flow turbomachinery (see Fig. 1) to distribute flow entering a machine radially to the blading. The observations reveal that above a critical Reynolds number the flow swirls circumferentially around the ring chamber. The device then performs much like a vortex valve, a strong vortex being created in the exit tube beyond the center body. It is shown that the pressure loss in this case can be calculated fairly well using an analysis similar to that of Binnie and Hookings [1]. The exit-tube vortex is also responsible for the occurrence of a piercing whistling sound the frequency of which can be estimated using Vonnegut’s [2] theory for the vortex whistle. Observations are also presented for the symmetric flow situation which occurs at subcritical Reynolds numbers and for the case where swirl in the ring chamber is prevented by a baffle.

scholarly journals Development of a Two-Chamber MHD Tundish for Metal Ca

2021 ◽  
Vol 17 (4) ◽  
pp. 19-24
Author(s):  
Oleksii Smirnov ◽  
Anatoliy Narivskiy ◽  
Yevgen Smyrnov ◽  
Aleksei Verzilov ◽  
Anastasiia Semenko ◽  
...  
Keyword(s):  
Electromagnetic Field ◽  
Continuous Casting ◽  
High Efficiency ◽  
Direct Action ◽  
Physical Modelling ◽  
Liquid Jet ◽  
Continuous Cast ◽  
First World ◽  
Inlet Chamber

Introduction. The multifunctional magnetodynamic tundish prototype is the first world magnetodynamic mixer and batcher for steel, which has a capacity of up to 10 tons of melt and an inductor electric power of 600 kW. Ithas been successfully introduced into industry. Further works aim at adapting this device to continuous casting, in particular at obtaining semi-continuous cast billets at metallurgical micro-plants.Problem Statement. Today, the study of the effect of electromagnetic field on melt stirring and removal of non-metallics in the inlet chamber of MD-T is an urgent task.Purpose. The purpose of this research is to substantiate and to create MD-T as a two-chamber aggregate additionally equipped with a few electromagnetic & MHD devices for different purposes, to be used at metallurgical micro-mills.Materials and Methods. Physical modelling has been applied for studying liquid metal stirring under the action of electromagnetic field and the removal of non-metallics.Results. The behavior of the liquid jet falling from the ladle into the centrifugal chamber has been studied. The influence of the rational liquid level in the centrifugal chamber, which is exposed to the direct action of the electromagnetic field, has been estimated. It has been established that the effect of rotation of the total liquid volumehas been achieved at the height of application of electromagnetic field, which is 0.2—0.3 of the total fill height. Increasing the height of the application of a magnetic field leads to the capture of the upper layers of the liquid.Conclusions. There have been proposed a new design of magnetodynamic tundish (MD-T) for continuous casting of steel. The use of tundish with a rotational motion of the flow may significantly reduce the number of large oxide inclusions (larger than 10 µm) in steel. The device has been successfully tested and its application will improve the quality of cast billets, extend the functionality of equipment and technologies, and enable the realization of modern high-efficiency processes of continuous casting.

scholarly journals Tolerable Risk for Hydrogen Sulfide in Sewage Treatment Plant- STP

2022 ◽  
Vol 16 (4) ◽  
pp. 74
Author(s):  
Mohieldeen M. A. Ahmed ◽  
Mohammed H. M. Gaily ◽  
Khalid M.O. Ortashi ◽  
Omer M.A. Al Ghabshawi ◽  
Nagwa F. Bashir ◽  
...  
Keyword(s):  
Hydrogen Sulfide ◽  
Activated Sludge ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Radiation Hazard ◽  
Activated Sludge Process ◽  
Outlet Channel ◽  
Toxic Gas ◽  
Inlet Chamber

Hydrogen sulphide is a toxic gas, it can cause a range of physiological responses from simple annoyance to permanent injury and death. There are a number of approaches to deal with the impacts of toxic gases. This study focused on minimizing the hazard exposure for hydrogen sulfide in the different operational zones for activated sludge process in sewage waterplant. Research tools/ approaches conducted were interviews, toxic gas testers, analysis report interpretation &amp; quantitative risk assessment method. The study was conducted on Arabian Peninsula during the period (September 2019- September 2021). The (13) operational locations tested for toxic gas concentrations were inlet chamber, outlet channel, coarse /fine screens, primary sedimentation tank, activated sludge tanks, secondary sedimentation tanks, gas desulfurization unit, disc filters, chlorine dosing unit, sludge dewatering, sludge silos and digester tanks. The study found that the highest concentration for H<sub>2</sub>S in the inlet chamber/ outlet channel. The severity hazards in the sewage treatment plant using activated sludge process are the asphyxiation by H<sub>2</sub>S was extremely high can cause harm to public health, followed by the radiation hazard followed by electrical hazard, then (working at height, mechanical, traffic, health, chemical, physical, ergonomic, environmental, microbial and natural). The frequency of hazards occurrence is asphyxiation by H<sub>2</sub>S was extremely high followed by the radiation hazard and health hazard including the infection with Covid 19 virus followed by mechanical hazard then (electrical, traffic, ergonomic, natural, chemical, physical and natural). Control measures were recommended to minimize the risk of asphyxiation by H<sub>2</sub>S in the working environment at the STP.

scholarly journals Strength and Service Life of a Steam Turbine Stop and Control Valve Body

2021 ◽  
Vol 24 (4) ◽  
pp. 61-70 ◽  
Author(s):  
Andrii S. Koliadiuk ◽  
◽  
Mykola H. Shulzhenko ◽  
Oleksandr M. Hubskyi ◽  
◽  
...  
Keyword(s):  
Service Life ◽  
Steam Turbine ◽  
Three Dimensional ◽  
The Body ◽  
Valve Body ◽  
Control Valves ◽  
Operating Modes ◽  
And Control ◽  
Inlet Chamber ◽  
Creep Strains

The stability of operation of steam turbines depends (along with other factors) on the reliable operation of their steam distribution systems, which are based on stop and control valves. This paper considers the strength of the elements of the K-325-23.5 steam turbine valves, in whose bodies, after 30 thousand hours of operation, cracks came to be observed. Previously determined were the nature of gas-dynamic processes in the flow paths of the valves and the temperature state of the valve body in the main stationary modes of operation. To do this, a combined problem of steam flow and thermal conductivity in stop and control valves was solved in a three-dimensional formulation by the finite element method. Different positions of the valve elements were considered taking into account the filter sieve. The assessment of the thermal stress state of the valve body showed that the maximum stresses in different operating modes do not exceed the yield strength. Therefore, the assessment of the creep of the valve body material is important to determine the valve body damage and service life. Modeling the creep of the stop and control valves of the turbine was performed on the basis of three-dimensional models, using the theory of hardening, with the components of unstable and steady creep strains taken into account. The creep was determined at the maximum power of the turbine for all the stationary operating modes. The maximum calculated values of creep strains are concentrated in the valve body branch pipes before the control valves and in the steam inlet chamber, where in practice fatigue defects are observed. However, even for 300 thousand hours of operation of the turbine (with a conditional maximum power) in stationary modes, creep strains do not exceed admissible values. The damage and service life of the valve bodies were assessed by two methods developed at A. Pidhornyi Institute of Mechanical Engineering Problems of the NAS of Ukraine (2011), and I. Polzunov Scientific and Design Association on Research and Design of Power Equipment. (NPO CKTI) – 1986. The results of assessing the damage and the turbine valve body wear from the effects of cyclic loading and creep of the turbine in stationary modes for 40, 200 and 300 thousand hours show that the thermal conditions of the body in the steam inlet chamber are not violated (without taking into account possible body defects after manufacture). The damage in valve body branch pipes after 300 thousand hours of operation exceeds the admissible value, with account taken of the safety margin. At the same time, the damage from creep in stationary operating modes is about 70% of the total damage. The maximum values of damage are observed in the areas of the body where there are defects during the operation of the turbine steam distribution system. The difference between the results of both methods in relation to their average value is ~20%.

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