Tube Plate Research Articles

Visual inspection and microhardness based studies of friction welding of tube to tube plate using an external tool

Conventional Friction welding is a well-established solid state welding process. However, this method has a limitation that it is not suitable for tube to tube plate welding. An innovative variant of this process, named Friction welding of tube to tube plate using an external tool (FWTPET) is gaining popularity in industrial applications as a potential alternative to its fusion welding counter parts. This process can be used to join not only similar but also dissimilar metals. The major parameters of this process include the speed of rotation of the tool, plunge depth and plunge duration. In this work, the effect of plunge duration and tool rotational speed on the quality of FWTPET process is investigated using visual examination and microhardness analysis of tube to tube plate joints between two grades of Aluminium alloys welded under various conditions. The results of the visual inspection are used to examine the parameters for optimal flash deposition without causing excessive internal material loss. The effect of plunge duration and tool rotation speed, on the microhardness of the weld, is also studied in this work and the results show that at higher plunge durations and tool rotational speeds, the micro hardness tends to drop. Microstructural analysis shows that the grain coarsening happens due to dynamic recrystallization, similar to that in Friction Stir Welding.

Metal Joining Technique of SA 213 Tube and SA 387 Tube Plate Grade Materials Using Backing Block by Clearance Fit Condition

This work, Seamless Austenitic 213 tube is welded with Seamless Austenitic 387 tube plate through friction welding of tube to tube plate using an external tool (FWTPET) method in presence of backing block by using clearance fit method. Further, the analysis of microstructural features on the interface of weld exhibit that the FWTPET is able to generate flawless welds. In all nine various work specimen which welded under the various circumstances, the hardness value, tensile strength have taken. In this work, two type of specimen has taken where one kind is the tube which contains no hole and another one is with the hole in the circumference. 806.28 MPa and 746.5 MPa were the optimum strength for the workpiece which is not a having a hole and having the hole on the circumference.

Experimental Analysis of SA213 Tube to SA387 Tube Plate Welding by Using Close Fit Technique in Absence of Supporting Plate

In this study, Friction Welding of Tube to tube-Plate using an External Tool (FWTPET) is carried out by joining SA213 tube and SA387 tube plate alloying materials using an external tungsten tool by close fit methods in absence of backing plate without hole on the circumference of the tube for superior mechanical and metallurgical properties. The optimization techniques such as Taguchi L9 and Analysis of Variance (ANOVA) is used to endorse the capital joint strength. The output parameter (TS) and input factors (tool rotational speed, tube projections, depth of cut) are designated for the study. The heat that produces from tool pin, dissipates to the tube and the tube plate during FWTPET process. The grain size measurement, x-ray diffraction (XRD) phase analysis, radiography test is carried out after FWTPET process. In this research work, FWTPET process is carried without hole on the circumference of the tube, further FWTPET process is also compared by without employing supporting arrangement. Excellent joint strength of 762.2 MPa is achieved with the absence of supporting specimen which without hole on the circumference of tube for the tool rotational speed of 1300rpm. Keywords: Friction welding, FWTPET, Analysis of Variance (ANOVA), Optimization techniques, Tensile strength

Creep-fatigue endurance of a superheater tube plate under non-isothermal loading and multi-dwell condition

Raising the operating temperature to increase electricity production in the nuclear power industry is a practical solution in the aspect of efficiency and emissions reduction. However, regarding structural integrity, such high temperature has a significant impact on the life of nuclear power plant components. The superheater tube plate is one of the most critical parts under exposures of very high temperature in the boiler system of the power plant. This study investigates creep-cyclic plasticity behaviour of a superheater outlet tube plate under extremely sophisticated thermo-mechanical loading and evaluates creep-fatigue damage endurance, using the modified LMM eDSCA. Temperature-dependent material properties are employed to calculate more practicable structural behaviour and lifetime prediction. The results clearly present the criticality of the effects of non-isothermal loading and multiple dwells on the structural integrity of the tube plate. Also, this study clarifies critical factors that cause dominant damage to the tube plate by providing total damages using various damage assessment models, of which results show the trend of the conservativeness of each damage assessment model, compared to experiment result.

Strength and hardness studies of C44300 tube to AA7075-T651 tube plate threaded and unthreaded dissimilar joints fabricated by friction welding process

Friction welding is an important process used nowadays especially for joining dissimilar metals in engineering and allied industries. The joining of dissimilar materials is different from the conventional materials and needs proper care and technology advancement. The objective of the present research is to investigate the strength of friction welded joints in the absence of backing block. Two conditions of tube and tube plates with thread pair and without thread pairs are considered for the experimentation. The effect of process parameters on the strength has been arrived. Microstructure at the weld joint interface indicates the high level of refinement at the weld zone. Scanning Electron Microscopic (SEM) images are used for investigating the intermolecular bonding of the tube and tube plate. Micro cracks are observed at the interface. Absence of backing block is the cause for the defect. Energy Dispersive Analysis (EDX) and X-Ray Diffraction (XRD) test are used for analyzing the material properties and quantification of crystalline phases.

Experimental study on the tube plate PV/T system with iron filings filled

This paper proposes a novel photovoltaic/thermal (PV/T) system – the iron filing filled tube plate PV/T system (IFTP system), for solar energy collection efficiently. In the system, the Tube plate solar collector is adopted to convert solar radiation to electricity and thermal energy simultaneously. To improve the structure of the traditional tube plate PV/T module, this paper presents a new tube plate PV/T module which filled with iron filings instead of air between the absorbing plate and fluid channel to increase the heat transfer between the fluid and photovoltaic cells. After that, an IFTP system is constructed and tested according to the related standards test under laboratory conditions. Experimental research is carried out under five groups of different radiation intensity (400–800 W/m2). The experimental results demonstrate that the temperature of IFTP module in effectively reduces by 3.5–6.5 °C, and the photoelectric efficiency increases by 19.8% compared with traditional tube plate PV/T system. The IFTP system takes a shorter period of time to achieve the same temperature difference of tanks.

Optimization Performance on Plate Fin Tube Heat Exchanger

The main objective of the present work is to investigation of optimum design of plate fin tube heat exchanger using Computational fluid dynamic approach and maximizing thermal performance. There are total five designs of plate fin and tube heat exchanger are used in present work and CFD analysis have been performed in it to get maximum heat transfer. It has been observed from CFD analysis that the maximum heat transfer can be achieved from plate fin and tube heat exchanger with elliptical tube arrangement inclined at 30o with 23.22% more heat transfer capacity as compared to circular tube plate pin heat exchanger. So that it is recommended that if the plate fins and tube heat exchanger with inclined elliptical tube used in place of circular tube arrangement, batter heat transfer can be achieved.

ABOUT THE USE OF TERMS «TUBE SHEET» AND «TUBE PLATE»

Development of scientific and technical knowledge, creation of new sci- ence disciplines arise the need for a standard for technical terminology. It is a serious problem to organize a lot of new terms. The clear fixed content is the main requirement for new terminology. In this paper, authors analyzed the use of well known terms «tube sheet» and «tube plate», which duplicates one another and are used to describe similar parts. This duplication is seen in various regulatory and technical documents that governs manufacturing technology, repair and operation of shell-and-tube heat exchangers, and also equally used in modern educa- tional and scientific literature. Authors analyzed the terms used in regulatory documentation, technical documentation, and in scientific papers. This analysis was performed on domestic resources and existing regulatory documents used in the US, Great Britain and many EU countries. The analysis of the usage of «tube sheet» and «tube plate» in the scientific and technical documentation, and scientific publications shows that there is no common view among the scientific and manufacturing community on what term should be used to refer to the part description, and therefore terms are used randomly. Terminology analysis given in this paper shows that the term «tube sheet» is preferred, it has one meaning for different construction designs, it is brief and corresponds to norms and rules of Russian language, and has all the necessary and sufficient features.

Numerical Analysis on Flow Field of Inlet Chamber for Heat Exchanger Based on CFD

.Taking the uniformity of the flow field and pressure field on the tube plate as a measure, this paper designs four kinds of circular distribution plates which is installed at the chamber to improve fluid field distribution. The simulation on CFD results show that the circular distribution plate can improve the flow field distribution and pressure field distribution obviously on the tube plate. Under the condition of a certain opening rate, when the diameter ratio of the circular plate to the tube plate is about 0.5, the distribution of the flow field and the pressure are more uniform.The research results have a certain guiding significance for the selection and design of the circular distribution plate in the inlet chamber.

Improving the Technology Used in Fabrication of Tube Bundles of Heat Exchangers Produced from 12Cr18Ni10Ti Steel by Means of Friction Welding

12Cr18Ni10Ti steel is widely used in the production of heat exchangers that function under high temperatures in corrosive environments. The technological process involved in the production of heatexchanger tubes with tube plates from this brand of steel, which includes the use of arc welding, is greatly complicated by the need to carry out thermal operations to achieve the required operating properties of composite joints of 12Cr18Ni10Ti steel, including resistance to intercrystalline corrosion. Replacement of arc welding by rotary friction welding represents an effective means of eliminating thermal operations in the manufacture of the tube bundles incorporated into heat exchangers, though no data is currently available on the properties of welded joints produced from 12Cr18Ni10Ti steel by friction welding. An evaluation of the potentialthat may be gained with the use of friction welding to produce composite joints with analternative design is presented here. The structures of the metal are investigated and statictension and impact bend tests of specimens of 12Cr18Ni10Ti steel produced by friction welding carried out for this purpose.

Lateral performance of CRCS connections with tube plate

This paper presents experimental and analytical studies to evaluate the cyclic behaviour of Circular Reinforced Concrete column Steel beam (CRCS) connections. Two 3/4-scale CRCS specimens are tested under quasi-static reversed cyclic loading. Specimens were strengthened with a tube plate (TP) and a steel doubler plate (SDP). Furthermore; nine interior beam-through type RCS connections are simulated using nonlinear three-dimensional finite element method using ABAQUS software and are verified with experimental results. The results revealed that using the TP improves the performance of the panel zone by providing better confinement to the concrete. Utilizing the TP at the panel zone may absorb and distribute stress in this region. Results demonstrate that TP can be used instead of SDP. Test records indicate that specimens with TP, with and without SDP maintained their maximum strength up to 4% drift angle, satisfying the recommendation given by AISC341-2016 for composite special moment-resisting frames.

ЖАРОТРУБНЫЙ КОТЁЛ

A fire tube boiler (10), comprising a jacket (11) for containing the water to be heated and a tube bundle designed to convey exhaust gases, which is accommodated within the jacket (11), the boiler comprising at least two furnaces (13, 14; 18, 19) with a corresponding burner (13a, 14a; 18a, 19a) connected to a single tube plate (15; 20) to which the tubes (16; 21) of the tube bundle are connected at one end, the tubes leading at their end into an exhaust gas collection chamber (17; 22).

Buckling Analysis and Section Optimum for Square Thin‐Wall CFST Columns Sealed by Self‐Tapping Screws

Two columns of thin‐walled concrete‐filled steel tubes (CFSTs), in which tube seams are connected by self‐tapping screws, are axial compression tested and FEM simulated; the influence of local buckling on the column compression bearing capacity is discussed. Failure modes of square thin‐wall CFST columns are, first, steel tube plate buckling and then the collapse of steel and concrete in some corner edge areas. Interaction between concrete and steel makes the column continue to withstand higher forces after buckling appears. A large deflection analysis for tube elastic buckling reflects that equivalent uniform stress of the steel plate in the buckling area can reach yield stress and that steel can supply enough designing stress. Aiming at failure modes of square thin‐walled CFST columns, a B‐type section is proposed as an improvement scheme. Comparing the analysis results, the B‐type section can address both the problems of corner collapse and steel plate buckling. This new type section can better make full use of the stress of the concrete material and the steel material; this type section can also increase the compression bearing capacity of the column.

Application of elastic-plastic analysis method in high pressure heater tubesheet design

The design method of pressure vessel consists of the elastic analysis method and the elastic-plastic analysis method. The design method based on elastic-plastic theory with more complex computation process contributes to lightweight design, and avoids uncertainty of stress classification in the complex structures. Tubesheet is the main part of high pressure heater, which is very thick based on Chinese code GB151 for the design of heat exchangers. Increased tubesheet with large thermal stress are not conducive to manufacture, heat transmission and detection. The application of limit load method and elastic-plastic method in the analysis and design of high pressure heater tube is to provide direction for the lightweight research of tubesheet. It is shown that high stress appears on the inner wall of jointing of tubesheet with the head due to the original tubesheet owning enough rigidity related to thickness, which should be noted in the design. The limit load method and elastoplastic method could be assessed in the plastic collapse assessment after optimizing the thickness of the tube plate by 5% on the basis of the existing rule design. Compared with the limit load method, the elastic-plastic method could obtain higher limit load due to its higher computational precision. On the other hand, the design method of elastic-plastic analysis method is not required to consider the determination of limit load per ASME VIII-2 judged by its convergence. The elastic-plastic analysis method is worth further study, which is helpful to the revision and improvement of relevant standards in China.

UJI AKTIVITAS ANTIBAKTERI EKSTRAK KULIT BUAH JERUK NIPIS (Citrus aurantifolia Swingle) TERHADAP PERTUMBUHAN BAKTERI ISOLAT KLINIS

The objective of this research was to test antibacterial activity ethanol and ethyl acetate of lime peel (Citrus aurantifolia Swingle) extract by Minimal Inhibitory Concentration (MIC) and Minimal Bactericidal Concentration (MBC) against the growth of clinical isolate bacteria. The type of this study used laboratory experimental using sensitivity test, dilution of tube and spreading plate. The experimental design used Complete Random Design using three repetitions on three concentrations i.g 25, 50, and 75%. Data was analyzed by qualitative with measuring inhibit diameter zone bacterial and qualitative using Two Way Anova followed by BNT with α= 5%. The statistical analysis showed that the solvent factor and concentration factor was significantly against growing bacterial and there was an interaction affect of both factors on S. aureus growth. The result presented that the ethanol and ethyl acetate of lime peel extract strongly inhibited Staphylococcus aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa; and midly inhibited the growth of Klebsiella pneumoniae. The MIC ethanol and ethyl acetate of lime peel extract against S. aureus, S. epidermidis and P. aeruginosa was 25% and K. pneumoniae was 50%. The MBC showed that ethanol and ethyl acetate of lime peel extract killed bacteria P. aeruginosa at 15%, S. aureus, S. epidermidis at 20% and K. pneumoniae at 25%. Taken together, it can be concluded that ethyl acetate of lime extract more effective than that of ethanol extract was to inhibit and killed clinical isolate bacterial.Keywords: lime peel (Citrus aurantifolia Swingle), antibacterial activity, clinical isolate bacteria, MIC and MBC.

Surgical management of raised intra-ocular tension in the hostile ocular surface - recurrent tube erosion in a patient with systemic sclerosis: a case report

BackgroundThe surgical management of patients with uncontrolled glaucoma and scleroderma is challenging, as the hostile ocular surface poses a challenge to surgery. A serious complication is tube erosion, with the risk of subsequent endophthalmitis. Here, we present a novel technique of harvesting autologous tissue to successfully manage recurrent tube extrusion.Case presentationMG is a 60-year-old Arabic lady diagnosed with scleroderma, that was previously managed with systemic corticosteroids. She has chronic open angle glaucoma, with a failed left eye trabeculectomy, which was then managed by a Baerveldt tube (BVT) insertion. Eight months after this primary surgery, she developed an anterior uveitis. This was further complicated by conjunctival erosion, tube exposure, leak around the sclerostomy site and hypotony. The erosion was likely secondary to her tight eyelids as a result of her scleroderma. She was taken back to theatre for tube revision, with single layer amniotic membrane transplant (AMT) over the exposed area, but the tube was eroding again after 2 months. She eventually underwent tube extraction, pars plana tube plate stabilisation, pars plana vitrectomy (PPV), pars plana tube insertion, phacoemulsification and intra-ocular lens insertion, jointly with the vitreo-retinal surgeons and with high dose prednisolone cover both pre- and post-operatively. We harvested the capsule which had grown over the end plate of the original tube. We sutured this over the new tube, specifically over a single layer of tutoplast prior to conjunctival closure. Almost a year on, the pars plana tube remains in place with no complications.ConclusionsThis case highlights the role of a pars plana tube in cases of cicatricial disease, with the use autologous tissue instead of grafts wherever possible. In patients with systemic disease such as scleroderma, pre-operative immunosuppression helps to reduce the of erosion in difficult cases.

CirLoc3D-Visual Location Method for Robot Automatic Tube Plate Welding System

This paper mainly introduces a Cirloc3D-vision location method used in robot tube plate welding. The visual position system uses a point laser sensor to measure the photo height, and can through three points to ensure a place to correct the camera posture. The captured image is used to extract the location information by the template matching method and searching the center of a circle's method. Then the information is sent to the robot and leads the robot to run to the specified position. Finally the welding gun at the end of the robot begins to perform the precision welding of the tube plate. This method is fast and accurate, so it can provide accurate position and orientation information for six axes industrial robots.

A History of Switching-Mode Class-E Techniques: The Development of Switching-Mode Class-E Techniques for High-Efficiency Power Amplification

Improving the efficiency of vacuum-tube amplifiers by properly approximating the anode voltage and current waveforms was discussed and first demonstrated in the late 1910s. Researchers found that, if either the tube plate current or voltage is zero when the other is nonzero, then the loss must be zero and the efficiency equal to 100%. The required rectangular waveforms could be achieved by inserting harmonic resonators in the anode circuit and tuning them to the odd and/or even harmonics of the fundamental frequency (now called class-F). Three decades later, however, Model et al. demonstrated that this is not the only way to improve power amplifier efficiency: very high anode efficiency can be achieved without special tuning of the anode circuit at the particular harmonic, provided that the asymmetrical voltage and current waveforms are due to reactive impedances at the harmonics [1].

Bearing strength of shear connections for tubular structures: An analytical approach

This work deals with the prediction of the bearing resistance of elementary shear connections constituted by gusset plates and square hollow sections fastened with long bolts. The research is motivated by the lack of specific rules in international codes for this particular configuration. In fact, while in lap shear connections, single or double-sided, the holes are always confined out of plane, in case of connections with long bolts and gusset plates (typical of tubular structures), the holes are constrained out of plane outwards, but they are free to buckle inwards, providing a reduction of the bearing strength. Within this framework, the paper is aimed at the development of an analytical formulation for the prediction of the bearing resistance of connections with long bolts and square hollow sections (SHS). The proposal is based on the calculation of the post-buckling load of the tube plate subjected to bearing at the bolt hole, combining the Winter's formula (originally developed to predict the post-buckling strength of steel plates accounting for geometrical and mechanical imperfections) with a simplified FE model developed in SAP 2000. The procedure developed is presented in detail proposing a design equation for connections with long bolts, based on a formula suggested recently by Može (2014, 2016) suitable for the inclusion in code provisions such as EC3. The accuracy of the design equation is checked on the experimental data reported in a previous work of the same authors properly extended with parametric FE simulations to cope for variation of geometrical parameters.

An investigation of Boiler Grade Tube and Tube Plate without block by using friction welding process

FWTPET investigation was carried out to intensify mechanical properties by using the tungsten carbide alloy external tool. In this research probe, those mechanical and metallurgical resources enhancement was depleted by joining boiler grade materials chosen are SA 213 grade tube and SA 387 as tube plate. Even though there were certain research aspects acknowledged, this article was under the investigation of metal bonding technique at without supporting block conditions. Next step of research was being analyzed by Taguchi Optimization technique to diagnose most convincing parameter. Associated procedures of analysis of variance (ANOVA) used to analyses the variation among the groups of the convincing parameter. Output specification was considered as a superlative compressive strength which explores welding ability. The investigation was about by comparing clearance and interference fit method using without supporting block samples. The clearance and interference fit method superior strength exhibits in this FWTPET research space disclosed as 2256.32 MPa and 2275.75 MPa respectively.