Ultrasonic Inspection for Welds with Irregular Curvature Geometry Using Flexible Phased Array Probes and Semi-Auto Scanners: A Feasibility Study

Pipes of various shapes constitute pipelines utilized in industrial sites. These pipes are coupled through welding, wherein complex curvatures such as a flange, an elbow, a reducer, and a branch pipe are often found. Using phased array ultrasonic testing (PAUT) to inspect weld zones with complex curvatures is faced with different challenges due to parts that are difficult to contact with probes, small-diameter pipes, spatial limitations due to adjacent pipes, nozzles, and sloped shapes. In this study, we developed a flexible PAUT probe (FPAPr) and a semi-automatic scanner that was improved to enable stable FPAPr scanning for securing its inspection data consistency and reproducibility. A mock-up test specimen was created for a flange, an elbow, a reducer, and a branch pipe. Artificial flaws were inserted into the specimen through notch and hole processing, and simulations and verification experiments were performed to verify the performance and field applicability of the FPAPr and semi-automatic scanner.

Steam Generator Strength Computation for Nuclear Electric Power Plants of a Low Power

Today, the world oversees an explosive development of the nuclear power stations (NPS) of a low power. Most projects deal with pressurized water reactors and as a matter of fact with steam generators (SG). Ukraine has a well-developed engineering industry backbone that can be used for the production of the equipment required for the nuclear power plants of a low power. This scientific paper delves into the computations of the strength of elements used for the monotube steam generator with cylindrical coils that is the most presentable of all the projects in question in IAEA materials. Appropriate methods were developed to perform structural computations and steam generator strength computations. The mathematical model was developed that allows us to perform strength computations of the SG elements making use of the analytical method with reference to the Regulations and do simulations using the ANSYS software code. The specified elements include the body elements, in particular the cylindrical part, the flange, the bottom and the cover, including the heat carrier branch pipe and heat exchange tubes. The comparison of the data obtained by both methods showed their similarity and accordingly, the accuracy of the data that are indicative of the need for an increase in the wall thickness of the cylindrical part of the external branch pipe intended for the heat carrier. The body bottom strain for calculated dimensions exceeds the permissible value by 1.56 %. Since this value is 5 % lower than permissible values it is deemed that the strength condition is passed through. The simulation proved that the strength conditions are met for heat exchange tubes, for the body, the body cover, the body flange, the conical part of the external branch pipe intended for the heat carrier. Based on the analysis done, we would like to recommend performing strength computations using the normative method with the subsequent check out by the simulation using the computer code.

Leak location procedure based on the complex-valued FastICA blind deconvolution algorithm for water-filled branch pipe

Water pipe networks have a large number of branch joints. Branch joint shunting generates vortices in the fluid, which excite the pipe wall to produce a type of branch noise. The branch noise is coupled with the leak source signal through the pipe. Here, a novel leak location protocol based on the complex-valued FastICA method (C-FastICA) is proposed to address the leak location problem under the branch noise interference. The C-FastICA, a complex-value domain blind deconvolution algorithm, effectively extended the cost function, constraint function, and iteration rules of the instantaneous linear FastICA into the complex-valued domain. The C-FastICA method was used to realize the separation of branch noise and leak source signal. The experimental results showed that the separation efficiency of the C-FastICA was higher than that of time-domain blind convolution separation (T-BCS). Furthermore, the relative location error of the C-FastICA method to the leak point was less than 14.238%, which was significantly lower than in traditional T-BCS and direct cross-correlation (DCC) technology.

TECHNICAL AND METHODOLOGICAL JUSTIFICATION OF THE ORGANIZATION OF SELECTIVE COLLECTION OF MUNICIPAL SOLID WASTE IN A RESIDENTIAL DEVELOPMENT

Проведен анализ ситуации, сложившейся при совмещенном вывозе твердых коммунальных отходов (ТКО). В связи с тем, что используемые на сегодняшний день конструкции мусоропроводов не предназначены для селективного (раздельного) сбора ТКО, исследована возможность реновации и модернизации мусоропровода и мусоросборной камеры для селективного сбора ТКО в существующем многоквартирном доме. Авторами предложен вариант модернизации существующей системы сбора мусора, заключающийся в следующем: в мусоросборной камере располагается несколько контейнеров, вместо патрубка и шибера устроена единая конструкция на все контейнеры, оснащенная заслонками, которые открываются для нужного вида отходов при нажатии соответствующей кнопки на блоке управления. Для домов, в которых нет мусоропроводов, рассмотрена возможность организации уличной контейнерной площадки, предназначенной для селективного сбора ТКО. Для вычисления размеров необходимых контейнеров было проведено исследование по определению масс и объемов разных фракций ТКО, приходящихся на одного человека. По результатам исследования был выполнен расчет по подбору размеров контейнеров по всем видам отходов для мусоросборной камеры и для уличной контейнерной площадки, с определением периодичности вывоза ТКО. Разработан алгоритм по селективному сбору ТКО в существующей жилой застройке. We carried out the analysis of the situation with the combined disposal of solid municipal waste (SMW). Due to the fact that the designs of waste chutes used today are not intended for selective (separate) collection of SMW, the article examines the possibility of renovation and modernization of the waste chute and waste collection chamber for selective collection of SMW in the existing apartment buildings. The authors offer a variant of modernization of the waste collection chamber, which consists in the following: in the waste collection chamber there are several containers, instead of a branch pipe and a gate, a single apron is arranged for all containers, equipped with flaps that open for the desired type of waste when the corresponding button is pressed on the control unit. The possibility of organizing street container platform for selective collection of SMW was considered for the apartment buildings which do not have waste chutes. To calculate the size of the required containers, we conducted a study to determine the mass and volume of different SMW fractions per person. According to the results of the study, a calculation was made for the selection of container sizes for all types of waste for the waste collection chamber and for the street container site, with the determination of the frequency of SMW removal. An algorithm for selective collection of SMW in existing residential buildings has been developed.

Friction welding of carbon quality steel

The aim of the work is to study the possibility of using, instead of manual arc welding with a covered electrode, a method of friction welding of fittings and small-diameter branch pipes of hull power plants. The solution to this problem is possible on the basis of the application of the friction welding process of small diameter nipples and nipples. Given the insufficient theoretical and experimental study of the problem, it was necessary to solve the following scientific and technical problems: to develop the design of the models and the connected (conical) surfaces of the choke and branch pipe assemblies; substantiate the choice of optimal angles for preparing surfaces for welding; justify the choice and experimentally confirm the values of the welding mode parameters; to assess the quality of welded joints by non-destructive and destructive methods. The obtained positive results of the experimental study confirmed the technological feasibility and economic feasibility of using friction welding of carbon steel fittings and small-diameter nozzles.

Design of an induction brazing installation for connecting oil and gas equipment

The article is devoted to the design of a circuit diagram of an induction heating device. The work carried out a literature review in the area under consideration. The technology of manufacturing a union is considered, which consists of manufacturing a plug, a branch pipe and a flange. Conducted research and application of induction brazing and various fields. Various elements of the equipment used in the design process are considered. A schematic flow diagram of the induction brazing unit has been developed. As a result of the work, the design of the installation for induction soldering was developed and auxiliary materials (flux, solder) were selected.

A Study on the Evaluation of Flow Distribution Evenness in Parallel-Arrayed-Type Low-Pressure Membrane Module Piping

The objectives of this study were to measure the flow rate distribution from a header pipe to each module installed in parallel for a water treatment membrane filtration process in operation and to investigate the reason for an uneven distribution of the flow rate via the CFD technique. In addition, this study attempted to propose the ratio of the branch pipe to the header pipe required to equalize the flow distribution for the same membrane filtration process. Finally, the relationship between the Reynolds number in the header pipe and the degree of the manifold flow distribution evenness was investigated. Mobile ultrasonic flow meter was used to measure the flow rate flowing from the membrane module pipe to each module, and the CFD technique was used to verify this. From the results of the actual measurement using ultrasonic flow meter and CFD simulation, it was confirmed that the outflow flow rate from the branch pipe located at the end of the header pipe was three times higher than that of the branch pipe near the inlet. The reason was that the differential pressure generated between each membrane module was higher toward the end of the header pipe. When the ratio of the sum of the cross-sectional area of the branch pipe and the cross-sectional area of the header pipe was reduced by about 30 times, it was confirmed that the flow rate flowing from each branch pipe to the membrane module was almost equal. Also, if the flow in the header pipe is transitional or laminar (Reynolds No. is approximately 4000 or less), the flow rate flowing from each branch pipe to the membrane module can be more even.

Branch-Pipe: Improving Graph Skeletonization around Branch Points in 3D Point Clouds

Modern plant phenotyping requires tools that are robust to noise and missing data, while being able to efficiently process large numbers of plants. Here, we studied the skeletonization of plant architectures from 3D point clouds, which is critical for many downstream tasks, including analyses of plant shape, morphology, and branching angles. Specifically, we developed an algorithm to improve skeletonization at branch points (forks) by leveraging the geometric properties of cylinders around branch points. We tested this algorithm on a diverse set of high-resolution 3D point clouds of tomato and tobacco plants, grown in five environments and across multiple developmental timepoints. Compared to existing methods for 3D skeletonization, our method efficiently and more accurately estimated branching angles even in areas with noisy, missing, or non-uniformly sampled data. Our method is also applicable to inorganic datasets, such as scans of industrial pipes or urban scenes containing networks of complex cylindrical shapes.