Distributor Design Research Articles

Optimization of non-spherical particle flow in vertical waste heat recovery devices: Analyzing structural configurations

Vertical waste heat recovery devices are emerging but are immature. The vertical waste heat recovery devices of circular, square, and optimized designs were analyzed for a full capacity of 8 tons of sintered ore. Using DEM theory, the effects of particle size distribution, velocity, and wall forces on void fraction distribution and particle flow were examined. The circular device demonstrated superior mixed particle flow compared to the square device, achieving integrated flow for 50 % of particles in the cone, in contrast to 26 % for the square device. An optimized circular device achieved integral flow for 90 % of particles, significantly enhancing overall flow and reducing wall adhesion, attributed to its improved internal design. Through insert and distributor design, the overall particle flow within the device improved, with almost no particles remaining on the walls. These findings underscore the potential for enhanced heat recovery efficiency through optimized internal structures in waste heat recovery devices.

Modeling and optimizing gas solid distribution in fluidized beds

In fluidized bed reactors, uniform distribution of gas and solids is critical to achieve the desired hydrodynamic and kinetic performance. For FCC units, Technip Energies uses a proprietary distributor design to terminate both reactor risers and spent catalyst lift lines to distribute the exiting gas-solid stream into a fluidized bed.In Technip Energies' Resid FCC unit, air and spent catalyst are distributed from an upward flowing stream into a catalyst bed for coke combustion on catalyst. Proper distribution is key to achieve a uniform coke burn and an even temperature profile throughout the bed. In PropyleneMax™ Catalytic Cracking (PMcc™) technology, the reactor riser also terminates in a fluidized bed, requiring proper distribution of the hydrocarbon vapor and solid mixture into the reactor bed, which is key to providing adequate contact for further cracking to valuable products. This paper discusses Technip Energies' gas-solid distribution technology and the recent work performed to develop an improved distributor for use as a riser termination device in both the PMcc reactor and the RFCC regenerator to achieve improved performance. The use of CFD modeling to screen and evaluate the initial concepts and optimize the final selected concept are presented here. The performance matrices used to quantify the benefits of the optimized distributor design with respect to the existing one in the reactor application are highlighted, showing the benefits of improved gas solid distribution on hydrodynamic and kinetic performance. The paper presents a systematic approach to develop a novel industrial device using physics-based computational tools.

Research on Oil and Gas Adsorption Optimization Based on CFD Modeling and Process Simulation.

In the process of oil extraction and refining, some of the liquid light hydrocarbon components will inevitably evaporate into the atmosphere, causing serious air pollution and safety hazards. This paper is focused on oil and gas adsorption systems to comprehensively optimize key parameters by combining computational fluid dynamics (CFD) modeling with process simulation, enabling the efficient treatment of hazardous materials. First, a CFD model of the hydrocarbon adsorption process is established to the porous media model by a user-defined function (UDF). Subsequently, the mass transfer process of oil and gas in porous media is successfully simulated to obtain the gas distribution in an industrial fixed bed adsorption tower. The adsorption tank is intensified, and the gas distribution in the tank is improved by optimizing the height-to-diameter ratio of the equipment and the design of the intake distributor. Third, the cyclic two-tank adsorption model of the pressure swing adsorption (PSA) process is established for key parameters optimization. Finally, the operating parameters and conditions of the PSA process are suspected by considering five factors affecting the adsorption efficiency: adsorption time, adsorption pressure, adsorption temperature, feed flow rate, and purge ratio of the washing step.

Design and Optimization of Self-Compensation Oil Distributor for Hydraulic Motors

Design and Optimization of Self-Compensation Oil Distributor for Hydraulic Motors

PIV investigation on the effect of gas distributor design for fluidization of Geldart A spherical particles

This is a hydrodynamics study on gas distribution during fluidization of the industrially relevant Geldart A type particles. The impact of 10 different distributor designs comprising perforated distributors (pitch and orifice arrangement pattern varied) and nozzle distributors (nozzle size varied) were studied experimentally on a bench-scale unit. Particle flow homogeneity in air was determined by a novel Particle Image Velocimetry (PIV) analysis of the freeboard velocity field. Over 50 PIV particle phase vector field images are presented and analysed. Bed expansion, Particle attrition with and without fines, velocity profiles with and without fines and effect of fines on bed expansion were ascertained. Best distributor design for a unit such as Fluid Catalytic Cracking (FCC) regenerator and FCC riser were found to be 0.8 cm and 0.6 cm nozzle plates distributors respectively. Confirmation with previous study revealed a correlation between homogeneous distribution of particulate flow and lower number of turbulence zones.

Increasing Economic Efficiency When Creating a Dynamic Microclimate in Compressed Conditions of Production Premises

This work is devoted to increasing economic efficiency when using two-stream air distributors that form a swirled and flat stream while providing a dynamic microclimate in compressed conditions of industrial premises. The design of a two-jet air distributor is proposed, which forms a swirled and flat laying air jet, that provides intensive attenuation of air flow velocity and temperature in stationary and variable mode. Measures aimed at saving cold energy are considered, namely, air supply in a variable mode, use of the flooring effect, use of devices for intensification of tidal flow turbulence. A set of optimal measures for obtaining the maximum economic effect is determined. A method of development and calculation of inflow mechanical ventilation systems based on the specified air distributors is proposed. The economic evaluation of the use of air distribution devices proved that the use of a two-jet air distributor makes it possible to obtain some economic effect.

Interplay of Residence Time Distribution and Electric Chaining Tendency due to Distributor Design Determine Electrocoalescer Performance

Interplay of Residence Time Distribution and Electric Chaining Tendency due to Distributor Design Determine Electrocoalescer Performance

Design and optimization of an air distributor for an almond stockpile heated and ambient air dryer (SHAD) - Part 1

Design and optimization of an air distributor for an almond stockpile heated and ambient air dryer (SHAD) - Part 1

Study on Optimal Design of Constant Current Water Distributor

Daqing Field has entered the late stage of ultra-high water cut development. The number of subzones of water injection wells is increasing year by year, and the number of zones of high-efficiency annual survey has exceeded 240,000. The testing capacity has reached a bottleneck, the contradiction among test efficiency, test team and qualified rate of water injection is becoming more and more obvious. The constant flow water distributor can keep the water injection quantity of the applied layer basically unchanged under the frequent fluctuation of water injection pressure, the water injection zone will be changed from repeated adjustment to little adjustment or even no adjustment, greatly reducing the testing workload and improving the testing efficiency. In order to further improve the performance of constant-current water distributor, the stress simulation of valve spool of constant-current water distributor was carried out. Based on the mechanical analysis of the valve core of constant flow distributor, the force acting on the valve core of constant flow distributor is obtained by numerical simulation, and the accuracy of the simulation results is verified by laboratory experiments. According to the requirements of starting pressure difference and spring stiffness of constant current water distributor, the constant current water distributor is optimized and perfected. The experimental results show that the error is less than 5%, which meets the requirements of field application. This study provides a basis for further improving the design of constant-current water distributor. Up to now, 392 wells have been tested with constant-current distributor, the effect of constant-current is good, and the average efficiency of single well is increased by 28.3%.

Computational fluid dynamic analysis of a novel particle-to-air fluidized-bed heat exchanger for particle-based thermal energy storage applications

Long-duration energy storage technologies are being targeted to enable cost-effective, decarbonized energy systems. Particle-based thermal energy storage systems are one promising technology by storing excess electricity or heat as sensible thermal energy in inexpensive, solid, inert particles. These systems are only possible if an effective and economical particle-to-working fluid heat exchanger exists. This study predicts the performance of a proposed, direct-contact, particle-to-air, pressurized fluidized-bed heat exchanger using computational fluid dynamics. The common Eulerian-Eulerian framework for modeling fluidized beds is first benchmarked to experimental results at a previously untested operating condition and application. Then, the benchmarked model evaluates the performance of a proposed design for a commercial-scale version of the novel particle-to-air heat exchanger. The results show pressure drop and gas-phase approach temperatures are advantageous compared to other proposed designs for particle-to-air heat exchangers in the literature; approach temperatures were less than 5 °C and gas-phase pressure drop across the fluidized bed was 32 kPa. The model also highlights the importance of gas distributor design and representation in the Eulerian-Eulerian framework to control fluidization behavior. The model built and benchmarked in this study can be leveraged to advance the design and analysis of these heat exchangers critical to the deployment of a promising long-duration energy storage technology.

Experimental study on the influence of distributor types on the property effect of finned evaporator

This study aims to increase the heat exchange performance of finned evaporator at different temperatures. To this end, the influence of the construction design of distributors on the shunt performance of the rectifier nozzle-type critical distributor (RNCD) was analyzed in-depth. The Second-generation rectifier nozzle-type critical distributor (SRNCD) was designed and improved based on the first-generation rectifier nozzle-type critical distributor (FRNCD). The SRNCD further improved the shunt performance by reducing the internal pressure drop. The performance of air coolers installed with the FRNCD, SRNCD, Venturi distributor, and CAL distributor was experimentally examined. Several parameters were analyzed, including refrigerating capacity, overall heat transfer coefficient, unevenness of distributor, and pressure drop. The results indicated that when the temperature of the test chamber was −18 °C, the refrigerating capacity of the finned evaporator of the SRNCD was 28.19% and 23.88% higher than those of CAL and Venturi distributors, respectively. The overall heat transfer coefficient was enhanced by 29.54% and 27.38%, respectively. The critical distributor theory of the rectifying nozzle provided new thoughts for the application and promotion of the new distributor. In short, RNCD has a broad application prospect.

Mathematical Modelling and Designing of a Universal Conical Spreader for Granular Material

Abstract A universal conical spreader for uniform distribution of granular fertilizers and seeds of grain crops, grasses is proposed. The developed universal conical spreader is designed for subsurface application of above-mentioned granular materials using seed drills and can be used as a passive distributor in a wide variety of applications. The methods of theoretical mechanics and descriptive geometry, particularly the method of replacement of projection plane have been applied to arrive at the design of the cone – the shape of conical spreader. A parametric equation was derived for the truncated part of the cone, which is an ellipse. The unique design of the cone-shaped distributor has a truncating form in the direction transverse to the movement of the seeder. In order to determine the interval of variability of spreader parameters more precisely, an analysis was carried out using a Mathcad-15 software. The results of theoretical research were confirmed in the laboratory and field conditions. The width of seed distribution, uniformity, and stability of distribution were studied to arrive at the most effective cone distributor design. The smallest values of non-uniformity and instability of material distribution of experimental coulter are reached at the values of factors D = 117–119 mm, h = 17–18 mm, and H = 32–35 mm.

Numerical Optimization Study of the Resistance Coefficient of U-Shaped Air Distributor

In this paper, the optimization of the flow channel structure of the U-shaped air distributor is proposed. Fluent meshing was used to mesh the multipatch meshing of the original model of the grid air distributor, and then the CFD numerical simulation was carried out by using Fluent 2022R1 to obtain the internal air flow state of the air distributor flow channel. Through the orthogonal experimental design and a comprehensive analysis method, the optimal size structure for resistance performance is obtained as S = 60 mm, RL = 125 mm, L = 160 mm, D = 100 mm, the resistance coefficient of the new structure as 1.375, and the pressure loss as 56.87 Pa, by using 3D modeling software (SOLIDWORKS 2015) and Fluent. Compared with the initial scheme, the resistance coefficient and pressure loss are reduced by 3.03% and 6.29%, respectively. To summarize, the research in this paper offers a substantial contribution to the realm of energy conservation and emission abatement in ship air conditioning systems, simultaneously furnishing invaluable guidance for the design of air distributors.

A novel design of distribution zone in scaled‐up PEM fuel cells based on active control of transverse flow

AbstractThe flow distribution is of significance to the fuel cell performance and durability, which has been studied from a theoretical and practical level in this work. The transverse‐flow‐control‐based mechanism behind flow distribution processes is revealed. The core lies in the reasonable generation and distribution of transverse flow, which are the prerequisite and co‐requisite for flow homogeneity. For the dual purpose, a novel design of combined‐mesh‐type distribution zone is proposed incorporating central horizontal meshes and lateral vertical meshes. The design philosophy and methodology are clarified. Under these guidelines, the novel distributor design is applied to different flow field plate geometries including the shorter distribution zone, higher expansion ratio, and scaled‐up fuel cell. Through organized and detailed simulations, two key geometrical parameters (porosities of central and lateral meshes) are quantified and the superior effect on flow distribution is validated.

Thermal performance analysis of a thermocline storage tank with integrated annular distributors

The implementation of single-tank thermocline storage systems in concentrating solar power systems is a promising solution to improve their stability and continuity. However, flow uniformity within the tank is crucial for achieving optimal thermal efficiency. Distributors have been used to homogenize flow uniformity, and their geometrical parameters significantly impact the thermal performance. In this study, a transient three-dimensional model was developed to investigate the effect of annular distributor gaps on temperature and velocity distribution during the charging and discharging processes. The results showed that the use of annular distributors prevented maldistribution of the thermocline layer, resulting in improved flow uniformity. Furthermore, the discharging efficiency initially decreased and then increased as the gap increased from 30 mm to 80 mm. The minimum discharging efficiency of 72.8% was observed at a gap of 50 mm. Therefore, this study provides an effective method for optimizing the design of annular distributors and presents a creative approach for improving the flow uniformity in thermocline storage tanks.

Design, conception, and assessment of an innovative liquid distributor for separation column

Liquid distributor is an important internal in packed distillation columns. One of the key features of this equipment is the drip point density, which corresponds to the number of irrigation points per area of the cross-section. For gravity liquid distributors, increasing the number of irrigation holes generally requires small hole diameters, which makes the equipment more sensitive to plugging. In this work, we disclose a new gravity liquid distributor that achieves large drip point densities without requiring smaller irrigation holes. This distributor is an adaptation of the classic orifice-pan type, in which we add a tree-like structure made of wires to spread the liquid dripping from the orifices. The liquid flows outside the wires and splits several times over the different branching levels before falling on the packed bed. From an orifice-pan configuration with drip point density of 736 pts/m2, we designed and constructed enhanced distributors with a theoretical irrigation density of 14,800 pts/m2. Performance comparison using a recently disclosed structured packing shows that these enhanced distributors can decrease HETP from 0.45 m to 0.27 m.

ТЕХНОЛОГИЯ РАЗДАЧИ ЖИДКОГО КОРМА НА ОСНОВЕ ШТАНГОВОГО РАЗДАТЧИКА

Dairy farming is the main responsibility of the agro-industrial complex, which widely uses priority technologies for keeping and servicing animals. To feed the animals of modern farms, productive mechanized equipment for distributing feed is used. The most interesting is the organization of feeding young animals. An emergency method has been developed for the mechanized distribution of liquid feed for calves in loose housing conditions. The limited mobile feeder is designed for use on farms, including keeping in boxes. The device of the liquid feed dispenser consists of a bar and is a conveyor with buckets for feeding fixed on it. The bar moves on rollers with the help of an electric drive, moves and transports buckets to use group cages with calf boxes. The length of the feeding front is 60 meters at one consumption by the operator. The liquid feed dispenser uses a milk pump NMU-6 with a capacity of 6.5 m 3 /h. An outlet valve with an outlet diameter of 20 mm is installed, which ensures the supply of liquid feed to buckets that are stationary. The speed of movement of the distributor rod is 0.07-0.13 m/s. In the event of a rapid dispensing of liquid feed, the feeder can move with a stop-stop to fill the buckets. The developed design of a limited-mobile rod distributor allows the most efficient use of the mechanized distribution of liquid feed to calves in their loose housing. The technology of liquid feed distribution based on a rod spreader reduces labor costs by 50%, eliminates heavy and monotonous work.

Gas/Liquid Operations in the Taylor-Couette Disc Contactor: Continuous Chemisorption of CO2

Gas/liquid contactors are widely used in chemical and biotechnological applications. The selection and design of bubble-column-type gas/liquid contactors requires knowledge about the gas distributor design to provide appropriate gas flow patterns. This study presents the continuous chemisorption of CO2 in 0.1 molar sodium hydroxide solution in a counter currently operated gas/liquid Taylor-Couette disc contactor (TCDC). This vertical-column-type contactor is a multi-stage agitated gas/liquid contactor. The performance of a lab-size TCDC contactor in gas/liquid mass transfer operations was investigated. The apparatus design was adjusted for gas/liquid operations by installing perforated rotor discs to provide a rotational-speed-dependent dispersed gas phase holdup in the column. The parameters of dispersed gas phase holdup, volumetric mass transfer coefficient and residence time distribution were measured. In the first step, hydraulic characterization was performed. Then, the efficiency in gas/liquid operations was investigated by continuous neutralization of 0.1 molar sodium hydroxide with a gas mixture of 30 vol% CO2 and 70 vol% N2. Temperature, rotational speed and gas flow rate were varied. The desired pH value of pH 9 at the column outlet was kept constant by adjusting the sodium hydroxide feed. From the experimental results, the volume-based liquid-side mass transfer coefficient kLa was deduced in order to model the reaction according to the two-film theory over the column height. The CSTR cascade model fitted the experimental data best. The experimental results confirm stable and efficient reactive gas/liquid contact in the Taylor-Couette disc contactor.

Numerical Investigation of Pelton Turbine Distributor Systems with Axial Inflow

In an agile power grid environment, hydroelectric power plants must operate flexibly to follow the demand. Their wide operating range and high part-load efficiencies allow for multi-injector Pelton turbines to fulfil these demands as long as the water jet quality is maintained. The water jet shape is governed by the flow in the distributor system. Pelton distributor systems with axial feed can potentially reduce the costs of the power station. Providing the flow quality at the nozzle outlet challenges the design of such Pelton distributors. Therefore, numerical simulations are performed to optimise a parameterised Pelton distributor system with axial feed. The effects of geometric parameter variations on its performance are studied. The criteria to evaluate the flow in distributor systems are presented, which are applied to quantify the power losses and secondary flows. Additionally, the second law analysis illustrates where the losses are generated. Due to various pipe bends, all designs exhibit a distinct S-shaped secondary flow pattern at the nozzle inlet. The simulations reveal that the power losses are greatly reduced by shaping the initial part of the branch line as a conical frustum. Deviation angles of the branch line close to 90° allow for lower secondary flow magnitudes at the nozzle inlet.

Optimal design of gas distributor in fluidized bed for synthesis of silicone monomer

The structure of the gas distributor is closely related to the production efficiency of organosilicon monomers. To improve the production efficiency of organosilicon monomers, this study uses Eulerian-Eulerian two fluid model and proposes a design formula for the gas distributor to optimize the gas distributor. It is proposed that the pressure drop of the gas distributor, the velocity nonuniformity coefficient, the relative standard deviation of the solid holdup, and the solid particle dispersion coefficient are used to evaluate the performance of the gas distributor. The results show that the performance of the gas distributor is significantly improved when the opening ratio Φ = 0.53% is optimized to Φ = 0.18%, in which the relative standard deviation of the solid holdup is reduced by 22%, and the solid particle dispersion coefficient is reduced by 40%. On this basis, this article studies the influence of different arrangements of vent holes on gas-solid fluidization characteristics. The results show that the circular arrangement of vent holes is helpful to the mixing of gas and solid.