Nozzle Replacement Research Articles

PROMISING TYPES OF HEAT STORAGE ELEMENTS FOR REGENERATIVE AIR HEATERS OF BLAST FURNACES

The paper considers the problem of improving the efficiency of operation of blast furnace air supply systems, which are equipped with regenerative heat exchangers with fixed refractory nozzle for heating hot blast. The existing methods of improving the performance of air heaters are analyzed. It is shown that further growth of thermal efficiency of regenerative heat exchangers by optimization of operation parameters or replacement of nozzles is impossible without increasing the overall parameters. As a perspective measure the use of heat storage elements with phase transition is proposed, where as a fusible insert compounds with a certain melting point are used, which corresponds to the operating modes of blast furnace air heaters. They have found application for heat storage in solar systems. Due to the "residual" thermal effect, the nozzles accumulate additional heat. This will increase the heat capacity of the heat exchanger and increase the hot blast heating temperature without changing the dimensional parameters. Operating conditions of air supply systems of blast furnaces are characterized by high temperature level, which is 1200–1350 °С, significant flow rates and speeds of hot and cold coolants, their increased pressure. Therefore, there is a question of choosing appropriate heatacumulative elements taking into account their properties and operating parameters of blast furnaces. Operation of such nozzles has revealed a number of problems, the solution of which requires additional research. For this purpose it is necessary to carry out modeling of quasi-stationary heat-exchange processes in the nozzle chamber of regenerative air heaters in order to select chemical compounds or their mixtures, which meet the operating conditions of blast furnace air supply systems, and to determine the optimal combinations of nozzle materials. Application of this technology will make it possible to obtain higher hot blast heating temper- ature, reduce metallurgical coke consumption or increase blast furnace productivity.

Theoretical study of the effect of fuel injection start pressure on the characteristics of the combustion process, indicators, and braking efficiency of the 2CH10.5/13 type engine

Introduction: Over time, demands on internal combustion engines are increasing, with a focus on fuel efficiency, emissions reduction, improved reliability, and cost-effective production and operation. Studying diesel engines like the 2CH10.5/13 is relevant due to their significant potential in the modern world. The purpose of study is to investigate the theoretical effect of the initial fuel injection pressure on the combustion process, engine braking performance and efficiency. Materials and Methods: The paper describes the methods of choosing injectors for diesel engines with a high-pressure fuel system. Results and Discussion: Using mathematical calculations and modeling is an effective means to prevent engine operation issues. Developing a dedicated calculation method is necessary to understand the impact of diesel fuel ignition volume on engine performance parameters. The results of experimental studies, which included non-motorised, motorised, and operational tests of diesel nozzles, are also presented. Studies have shown that after 4,000 cumulative hours of operation, the residual life of the injector nozzles is insignificant, since the dynamic performance of the diesel engine decreases to the limit value (7%). Conclusions: This may indicate the need for regular maintenance and replacement of nozzles in accordance with the manufacturer’s recommendations.

Analisa Pengaruh Metode Pencucian Nozzle Sludge Centrifuge terhadap Kehilangan Minyak pada Final Effluent

The clarification process is the separation of oil from the sludge using a sludge centrifuge. The process in this sludge centrifuge treats sludge/sludge output from CST in the form of sludge underflow. The problem that occurs in the oil separation process in the centrifuge is the high amount of oil that is still included in the final effluent as oil losses. High oil loss is caused by a blockage in the nozzle due to the operational process of the tool that does not pay attention to procedures (SOP) and the lack of operators in the sludge centrifuge related to the maintenance process (washing). The purpose of this study, namely to identify the factors that influence the causes of oil loss in the slugde centrifuge and final effluent, examine the effect of nozzle washing (flushing) on ​​oil loss in the sludge centrifuge and liquid waste production (final effluent), and determine the most optimum flushing method in terms of oil loss and liquid waste production. This research went through four stages, namely problem identification, cause analysis, effort solution, and optimum flushing method. The results of this study indicate that the standby nozzle replacement method is the optimum method because it does not require water, only takes 15 minutes, and has the lowest loss rate of 0.53%. It is hoped that with such results, companies engaged in palm oil processing can apply this method.

Обзор разработанных систем быстросъемного устройства гидравлического экскаватора

Nowadays the hydraulic excavator is one of the leading multifunctional machines that are operated for multi-purpose goals and are also finding increasing use due to the widespread use of replaceable working bodies and working equipment. It is important to note that the use of a wide range of replaceable working equipment and working bodies of excavators not only increases the productivity of machines, but also the level of mechanization of work. The possibility of easy replacement of nozzles increases efficiency and minimizes the likelihood of damage or wear of equipment associated with manual replacement of nozzles. Besides, this will reduce the time for replacing the working body and speed up the work process.This article analyzes and reviews research: publications, patents; also provides an assessment of the quality of the proposed solutions for quick fastening systems on hydraulic excavators.

3D-Printed disposable nozzles for cost-efficient extrusion-based 3D bioprinting

3D bioprinting has significantly impacted tissue engineering with its capability to create intricate structures with complex geometries that were difficult to replicate through traditional manufacturing techniques. Extrusion-based 3D bioprinting methods tend to be limited when creating complex structures using bioinks of low viscosity. However, the capacity for creating multi-material structures that have distinct properties could be unlocked through the mixture of two solutions before extrusion. This could be used to generate architectures with varying levels of stiffness and hydrophobicity, which could be utilized for regenerative medicine applications. Moreover, it allows for combining proteins and other biological materials in a single 3D-bioprinted structure. This paper presents a standardized fabrication method of disposable nozzle connectors (DNC) for 3D bioprinting with hydrogel-based materials. This method entails 3D printing connectors with dual inlets and a single outlet to mix the material internally. The connectors are compatible with conventional Luer lock needles, offering an efficient solution for nozzle replacement. IVZK (Ac-Ile-Val-Cha-Lys-NH2) peptide-based hydrogel materials were used as a bioink with the 3D-printed DNCs. Extrusion-based 3D bioprinting was employed to print shapes of varying complexities, demonstrating potential in achieving high print resolution, shape fidelity, and biocompatibility. Post-printing of human neonatal dermal fibroblasts, cell viability, proliferation, and metabolic activity were observed, which demonstrated the effectiveness of the proposed design and process for 3D bioprinting using low-viscosity bioinks.

Determination of the wear limit value, the optimal operating time, and the consumption of jet-forming elements made of different materials when implementing water jet technologies

By evaluating nozzle wear and predicting its dynamics, it is possible to determine and use the required operation modes of water jet devices, considering the minimum fluid pressure at which the specified cutting parameters (surface quality, slot depth) cannot be longer ensured, and, thus, determine the time of guaranteed compliance with cutting conditions and ensure timely replacement of nozzles.

Flow Simulation in Abrasive Fluid Jet Machining with Water as Carrier Medium using CFD

Tremendous growth is seen in the field Machining of Materials where the engineering applications are highly demandable. Currently Abrasive Fluid Jet Machining is used to machine wide range of Engineering and Structural Materials including Aerospace, Defense and Aircraft Application which require high strength to weight and stiffness to weight ratios. In Abrasive fluid jet machining the abrasives are premixed with a suspended liquid to form slurry. The flow of the Abrasive Fluid mixture through the nozzle, results in rapid wear of the nozzle which degrades the cutting performance. This may lead to the divergence of the Abrasive Fluid Jet such that the angle of impingement varies. This jet impingement angles have more influence on the machining responses than the normal jet impingement angle as the depth of cut is improved thereby minimizing the shallow cuts within the same total cutting time. Nozzle replacement cost plays a vital role in the economics of the machining process and improvements in its wear characteristics are critical for the growth of such machining technology. It is well known that the inlet pressure of the abrasive fluid suspension has significant effect on the erosion characteristics of the inside surface in the nozzle. An analysis was carried out with constant nozzle taper angle and water as carrier medium. The objective of this work is to analyse the effect of inlet operating pressure on wall shear and exit kinetic energy with respect to Carrier medium. The two phase flow analysis was carried by using computational fluid dynamics tool CFX. The availability of optimized process parameters of abrasive fluid jet machining is limited to water and experimental test can be cost prohibitive. In this case computational fluid dynamics analysis provided better results.

Control of the secondary cooling in continuous casting during nozzle replacement

The cooling and solidification of a continuous-cast ingot in transient casting conditions are studied by simulation. The influence of the method of controlling the secondary cooling on the thermal state of the ingot is shown. Different approaches to the control of the coolant flow rates in various operations are compared.

核电厂稳压器贯穿接管的修复和结构完整性评估

较早期核电厂的压力容器封头上的贯穿接管材料多为600合金，由于600合金对一回路水环境应力腐蚀开裂的抗性较差，易产生应力腐蚀裂纹贯穿压力边界而导致泄漏，可采用修复方法使用690合金接管更换损坏的接管，重构压力边界。为确保新压力边界能够达到原始设计要求，对重构压力边界的新接管及其焊缝进行结构完整性分析。对稳压器顶盖上的贯穿接管，进行重构压力边界的焊接修复和结构完整性评估，基于有限元分析获得工况瞬态热应力和焊接残余应力的基础上，依据ASME规范进行应力强度校核，并通过断裂力学计算分析假想裂纹在核电厂40年设计寿命内的扩展及稳定性，分析结果表明修复后的结构满足设计和使用要求。 Many NPP pressure vessel head nozzles were manufactured of Alloy 600. Since Alloy 600 is sus-ceptible to PWSCC, the degradation mechanism has been observed in these nozzles. The industry has used several methods to mitigate PWSCC, including replacement of nozzles fabricated of Alloy 690. After the replacement of the nozzle, the structural integrity analysis of new nozzle and welds should be performed to ensure the pressure boundary compliance with the original design re-quirement. The PWR pressurizer top head instrument nozzle is evaluated. Thermal stress of the transients was obtained from 3D FEM analysis and residual stress of J-groove weld was obtained from 2D FEM analysis. Stress intensities and residual stress were conservatively determined and used for the ASME Code, stress intensity analysis, fatigue crack growth analysis and fracture me-chanics analysis. All of the analysis showed that the repaired nozzle satisfies the ASME Code design requirement.

Laboratory and Full Boom-Based Investigation of Nozzle Setup Error Effects on Flow, Pressure, and Spray Pattern Distribution

Abstract.Pesticide application is an integral part of crop production, and ground-based agricultural boom sprayers are used extensively to apply pesticides to the crop canopy or soil surface across millions of acres in the United States. Efficient application is necessary to minimize costs and limit adverse environmental impacts. The goals of this study were to provide quantified measurements on the effects of nozzle setup errors on spray pattern uniformity and evaluate how laboratory patternator-based simulations would compare to measurements on a full spray boom. More specific objectives were to determine the effects of factors such as nozzle lateral angle, nozzle spacing, nozzle replacement, and nozzle pitch angle on spray pattern distribution and evaluate a simulation approach to predict the effects of single nozzle boom setup errors on full boom system pattern uniformity. Laboratory and sprayer-based tests were devised to quantify the impact of nozzle setup and operational errors on spray pattern uniformity, boom pressure, and nozzle flow rates. Results indicated that small variations in boom setup or nozzle operation (i.e., pressure or flow) can cause significant errors in spray nozzle distribution which may not be completely detectable by measuring spray pattern alone. Simulations using laboratory data from setup or operational errors reflected similar changes (differences less than 2.6%) in spray pattern CV as full boom data with similar setup errors. These findings were significant in that it may be possible to model errors within full boom spray distributions based on smaller laboratory-collected datasets. Keywords: Equipment, Equipment for crop protection, Patternator, Spray pattern distribution, Spraying.

Structural Integrity Analysis of Nuclear Power Plant Pressure Vessel Penetration Nozzle Repaired

Primary water stress corrosion cracking (PWSCC) has been observed in CRDM nozzles, BMI nozzles and other penetration nozzles. The industry has used the repair method of replacement of nozzles fabricated of Alloy 690. After the replacement of the nozzle, the structural integrity analysis of new nozzle and welds should be performed to ensure the pressure boundary compliance with the original design requirement. In this paper, the pressurizer top head instrument nozzle of PWR nuclear power plant is evaluated as a typical pressure vessel penetration nozzle. The results showed that the repaired nozzle satisfies the ASME Code design requirement and the crack growth of the postulated flaw in 40 years of the nuclear plant life is acceptable.PWSCC degradation mechanism has been observed in CRDM nozzles, BMI nozzles and other penetration nozzles [1]. In some nuclear power plants built in China earlier, such as DAYABAY nuclear power plant and QINSHAN nuclear power plant, PWSCC degradation mechanism has been found in CRDM nozzle welds which manufactured of Alloy 600 and welded of Alloy 82/182[2]. The repair of the degraded nozzles is the popular choice for the nuclear power plant owners. After the replacement of the nozzle, the structural integrity analysis of new nozzle and welds should be performed to ensure the pressure boundary compliance with the original design requirement. In this paper, the pressurizer top head nozzle of PWR nuclear power plant is evaluated as a typical pressure vessel penetration nozzle. Stress intensities were conservatively determined for pressure and applicable thermal transients and compared to the allowable values of the ASME Code, Section III. Thermal stress of the transients was obtained from 3D finite element model (FEM). Residual stress of J-groove weld was obtained from 2D FEM analysis and used for fracture mechanics analysis. All of the analysis showed that the repaired nozzle satisfies the ASME Code design requirement and the crack growth of the postulated flaw in 40 years of the nuclear plant life is acceptable.

Investigation and comparison of spray characteristics of pressure-swirl atomizers for a small-sized aircraft turbine engine

Abstract The quality of liquid fuel atomization highly affects the formation of gaseous pollutants and particulate matter emissions from combustion processes. Spray characteristics of two geometrically different pressure-swirl atomizers for a turbojet engine in light aircraft were measured on a cold test bench. A spill-return atomizer and its intended replacement simplex atomizer were investigated using Particle Image Velocimetry (PIV) and Phase-Doppler Anemometry (PDA). Single-camera and stereoscopic PIV measurements yielded velocity distributions in the axial cross-section of the spray cone. PDA measurements provided drop-size distribution and axial velocity data. Acquired results reveal significant differences in spray characteristics of the nozzles investigated at the same fuel injection pressures. The simplex nozzle produced spray with Sauter mean diameters lower by 5–20 μm depending on the regime, its spray was more stable but its shape greatly varied with fuel injection pressure. These differences are discussed in detail, their analysis indicate a potential for spray improvement provided by the novel atomizer design and elucidates the possible impact of the nozzle replacement on the combustion process.

Selection and maintenance of spray nozzles for pretreatment applications

Spray nozzle performance will have a significant effect on your system's operations and your operating costs. Taking steps to spot, solve, and prevent nozzle performance problems will be a worthwhile investment. Proper nozzle performance can reduce operating costs, reduce maintenance costs, and improve cleaning quality. The major factors in replacing nozzles are the cost of wasted water, chemicals, electricity, and the deteriorating quality of the product, resulting in rework and customer service problems. If nozzle replacement is found to be excessive, one can then be better equipped to judge the need to switch to different nozzle materials if there are excessive abrasive solids in the water that need to be removed. If your nozzles are wearing out rapidly just imagine the damage that is being done to the rest of the system. Proper spray nozzle maintenance procedures, and periodic replacement, will help your pretreatment system run at peak efficiency, producing a higher-quality finished product, and add to the profitability of your operation.

Sprinkler Head Maintenance Effects on Water Application Uniformity

The effects of wear on the ability of hand-move and side-roll sprinkler irrigation systems to maintain the designed water application rate and uniformity are of concern with regards to crop performance, water use efficiency, and environmental impact. Six hand-move and six side-roll sprinkler irrigation systems used under commercial crop production in Lane County, Oreg., were evaluated for equipment wear and performance. Individual sprinkler nozzle size and discharge rates were measured for each system and used in a computer model to estimate field application rate and uniformity. New nozzles were installed on six systems to compare potential application rate and uniformity with existing performance. Despite reducing the coefficient of variation in discharge between sprinklers from 10 to 2%, little increase in water application uniformity was attained. A 13% decrease in mean water application rate was documented after nozzle replacement. Ignored overapplication due to worn or mismatched nozzles results in overirrigation in both rate and total amount, which gives rise to the potential for increased surface redistribution and deep percolation, resulting in water and nutrient losses.

Bacterial Tracking in a Dairy Production System Using Phenotypic and Ribotyping Methods

A systematic sampling plan was designed to collect raw and pasteurized milk samples throughout a single-raw milk source, dairy-processing operation experiencing reduced product shelf lives due to bacterial contamination. The objectives were to track bacterial contamination sources throughout a complete dairy production system and use this information to reduce bacterial spoilage losses in processed fluid products. Over a 5-week period, 233 bacterial isolates were collected, representative of different colony morphologies on psychrotrophic bacteria count (PBC) plates. Forty-five isolates (19%) were obtained from pasteurized milk and 188 (81%) were isolated from raw product. Thirty isolates were identified as Pseudomonas spp. by Gram stain and biochemical methods. Of these, 27 (90%) were postpasteurization isolates and 3 (10%) were raw milk isolates. Automated ribotyping revealed that raw and pasteurized Pseudomonas fluorescens isolates were indistinguishable (similarity Index >0.93), suggesting the possibility of postpasteurization contamination with bacteria from raw product. In the plant, filler nozzles were identified as the primary reservoirs of postpasteurization contamination. Nozzle replacement produced significantly lower finished-product PBCs at 7 days postprocessing (>4-log reduction) and extended fluid product shelf life.

P.E.A. Products, Inc., an Affiliate of Precision Endoscopy of America, Inc., Announces the Flexible Endoscope Air/Water Nozzle Replacement Kit

P.E.A. Products, Inc., an Affiliate of Precision Endoscopy of America, Inc., Announces the Flexible Endoscope Air/Water Nozzle Replacement Kit

A Model for Sprinkler Nozzle Replacement

ABSTRACT A model for sprinkler maintenance by periodic nozzle replacement has been developed. The cost of water wasted due to nozzle wear and pressure variation was considered with respect to the sprinkler operating parameters, and it was found that significant savings could be achieved for both regular and flow controlled nozzles.

Nozzle replacement from outside is safe and efficient method

The entire interval from time of finish pouring to ladle ready for next heat is 12 to 15 min. Frequently, as many as five 190-ton heats are tapped in the same ladle during an 8-hr turn. Pouring practice is regularly 96 to 98 pct good pouring.