Increasing the Flow Capacity of Hoses with Electrical-Heater Coils to Supply Thickened Preservatives for Spraying

Introduction. Anticorrosion protection of agricultural machinery working elements is provided through using pneumatic application of thickened preservatives with heating. For this purpose, a wire coil is inserted inside the preservative-supply hose and connected to a current source. It is known that the wire thickness and the coil pitch affect the hydraulic resistance to fluid flow. However, it has not been established how the diameter of the coil insert and its heating affect the flow capacity of the flexible hose channel. The purpose of the research is to increase the capacity of a flexible hose with an electrical-heater coil. For this purpose, it is necessary to determine its geometric parameters minimizing the hydraulic resistance to the thickened preservative flow and reducing the energy consumption for heating the material in the hose. Materials and Methods. It is proposed to investigate two electrical-heater coils of the same length, but of different diameter, made of steel welding wire pieces of equal length. There was developed a stand to study the influence of the inserted coil parameters on the hose hydraulic resistance. The stand was used to determine pressure losses in hoses with coils and in smooth hoses when used engine oil and thickened preservative flow through them. The flow capacity of the hose with cold and heated coils was estimated. Results. The method of heating the preservative in the hose wall layer is justified. At the same time, its flow capacity increases one and a half times with less energy consumption (2.4 times) than when heating the preservative in the central part of the hose. Under laminar flow mode, the pressure loss in the hose is 2 times lower when the coil is equal to 0.85 of the hose channel diameter than when the coil is equal to 0.67 of the channel diameter. Discussion and Conclusion. The research found the rational way of placing the electrical coil near the heated hose channel wall. At low air temperature, the reduction of the thickened preservative viscosity by heating in the hose helps to decrease the pressure loss up to 50% and increase its flow capacity by 1.4‒2.0 times. The use of a electrical-heater coil in the hose with thickened preservative will minimize energy consumption when preserving equipment on open storage sites.

A method to optimize the length of flexible hose of the radial jet drilling technology

Radial jet drilling (RJD) technology has been applied to enhance the recovery of difficult-to-produce reserves by multiple horizontal micro-holes. The micro-hole length drilled by high-pressure water jets is of vital importance for the oil and gas recovery effect and is usually tens of meters long for applications in maturing oil fields in China. The water jets are generated by multiple orifices nozzle generally. Many studies focused on improving the self-propelled force generated by water jets to increase the micro-hole length. However, there are few researches on improving the micro-hole extension capacity in terms of optimizing the flexible hose that acts as the drill pipe in conventional drilling technology. This paper firstly studied the relationship between the flexible hose length and the micro-hole extension limit according to the analytical model to calculate the micro-hole extension limit. Then, the method to optimize the flexible hose length and the flow rate was developed aiming to obtain maximum micro-hole extension limit. The results show that the micro-hole extension limit decreases logarithmically with the increase in the flexible hose length under the condition that the takes the maximum value. The optimization model is applied by a field case and is proved to be effective to increase the micro-hole extension limit. This study is significant to improve the micro-hole extension capacity. Moreover, it provides a reference for the design of the hydraulics and selection of flexible hose for the RJD.

Performance and Feasibility Study of a Novel Automated Catch-Hauling Device Using a Flexible Hose Net Structure in Set-Net

The labor-intensive catch-hauling method in set-net fisheries faces problems of lower productivity, lower efficiency, and higher operational risk due to aging problem and labor insufficiency. To solve such problems, a novel catch-hauling device using the flexible fire hose and net (hose net), which is placed in the box chamber, was proposed in this study. The hoses were inflated with air injected into one edge of the hose net, and the buoyancy force increased: the net gradually floated up, cornering the fish in the opposite edge. To corner and harvest the fish efficiently and safely, the changing formation and motion parameters of the hose net are significant. A series of floating up, sinking experiments, and catch-hauling tests were conducted to evaluate the performance of this device. The results showed that the hose net could gradually float in an ideal form and sink smoothly through natural exhaust and stretched on the bottom of the water tank. The time spent and average speeds in floating and sinking processes varied with air pressure and airflow rate, allowing the hose net motion to be controlled in practice by adjusting the airflow. Through the catch-hauling test using live fish, most of the fish were directed into the fish bag. Two main capture failure phenomena were also observed. Overall, this newly developed automated catch-hauling device is expected to be successful for use in modern fisheries.

Assessment of the man-induced hazard in transporting oil from the unequipped sea coast to tankers via flexible hose pipelines

Выполнен анализ надежности технологического оборудования в составе гибкого трубопровода рукавного типа, а также проанализированы условия его функционирования в системе передачи нефти с необорудованного морского побережья в танкеры. Характеристики надежности оборудования выражаются через интенсивность отказов и длительность цикла транспортировки нефти. Количественным показателем надежности рассматриваемой системы принят технический риск. При частоте негативных событий от 10-2 до 10-4в год риск считается маловероятным, но может сопровождаться серьезными последствиями – в пределе – катастрофическими. Более точную оценку риска выполнить невозможно из-за неопределенности информации о временном цикле и характере реальных нагрузок на элементы системы. Проведена оценка воздействия поражающих факторов при авариях временных трубопроводов рукавного типа, развертываемых на необорудованном морском побережье. Выполнен прогноз величин потенциального и индивидуального пожарных рисков. Приведено обоснование их допустимого увеличения в соответствии с требованиями Федерального закона «О пожарной безопасности». The reliability analysis of process equipment as part of a flexible hose-type pipeline has been carried out, and the conditions of its functioning in the system of transferring oil from the unequipped sea coast to tankers have been analyzed. Equipment reliability characteristics are expressed in terms of the failure rate and duration of the oil transportation cycle. The technical risk is taken as a quantitative indicator of the reliability of the system in question. With a frequency of negative events of 10-2 to 10-4 per year, the risk is considered unlikely, but can be accompanied by serious consequences - in the limit - catastrophic ones. A more accurate risk assessment cannot be performed due to the uncertainty of information about the time cycle and the nature of the real loads on the system elements. The assessment of an impact of damaging factors in accidents with temporary hose-type pipelines deployed on an unequipped sea coast has been performed. The forecast of values of potential and individual fire risks has been made. The substantiation of their permissible increase in accordance with the requirements of the Federal Law "On Fire Safety" is given.

Experimental Study on Fish-Harvest Performance of the Flexible Hose Net

Set net fishery is one of the efficient fishery methods and has a history of several centuries in Japan. In 2017, fish harvest amount of set net fishery was 326,200 tons, about 10.2% of the total amount in Japan. The traditional method for harvesting fish is to use two fishing vessels to haul up the box chamber and obtain the fish in it, which requires supplementary equipment and human power. For reducing human power and safety, the automated net-hauling system has been developed. This system used a flexible hose net, with air injected from one side of the hose net, then the net could float up gradually and harvest the fishes. A new hose net was developed by reducing the number of air injection tubes from seven to two in comparison to the previous hose net. The paper presents the results of the animal experiment using 1/60 model of the flexible hose net. The fish-harvest effect in the flow are experimented by the Horizontal Circulating Water Channel. The fish-harvest effect was observed directly. The floating up velocity of the hose net can affect the fish-harvest rate. If the floating up velocity is too fast, the fish are easy to be stuck on the net and cannot swim forward to arrive at the catching spot (trap net). Therefore, the floating up velocity of the hose net not only determines the operational efficiency, but also affects the fish-harvest rate to some extent. Additionally, the deformation of flexible hose net was considered not only during the air injection, but also during the water intrusion.