Jolanta Janutėnienė

Analysis into the selection of a ballast water treatment system

Today, it is very important to select and install the optimal equipment for the treatment of ballast water in existing ships. Increasing cargo volumes demand for a greater number of ships for transportation and expanded navigation geography as well as result in increased amount of discharged ballast water. Consequently, sea water pollution is increasing and invasive microorganisms appear that the existing flora and fauna are unaccustomed to. In order to protect territorial waters from these invasive species, International Maritime Organization (IMO) requirements have been implemented that regulate the quality parameters of discharged ballast water from ships. This problem has become particularly relevant for operational ships, in which ballast water treatment equipment and technical solutions had not been anticipated in the design stage. This article provides a comparative analysis of the treatment equipment of ballast water and the related technical parameters, in order to distinguish the most important equipment criteria. A Carrier, according to its technical characteristics, was analysed together with the water treatment method for operated bulk. An expert evaluation for the characteristics of the technical equipment was established.

Investigation of the hydrodynamic processes of a centrifugal pump in a geothermal system

AbstractThe hydrodynamic and thermodynamic processes of geothermal well extraction are investigated and presented in this paper. The paper presents mathematical models for a multi-level centrifugal pump and pipeline system. The mathematical models were used to evaluate gas (nitrogen) emission in water and its effects on hydrodynamic processes. Experimental studies and mathematical modelling showed that the gas content of the fluid increases the pressure and flow pulsations within a centrifugal pump. The variation in the height of the liquid column in extraction has an influence on characteristics of the multistage centrifugal pump used in wells.

Influence of Dynamic Viscosity on Automatic Dynamic Balance

The paper deals with analysis of dynamic stability and behavior of automatic dynamic balance (ADB) by applying theoretical approach. Differential equations of the considered system were established using Lagrange equation. Numerical analysis of the dynamic equations was performed and influence of dynamic viscosity coefficient on self-balancing process was estimated. It is demonstrated that the balancing time decreases in non-linear character. The optimal value of dynamic viscosity for achieving minimal balancing time can be determined for the analyzed system.

Simulation of Hydrodynamics Processes of Hydraulic Braking System of Vehicle

The 3D vehicle with the hydraulic braking system and disc brake with the wheel has been investigated. The dynamic models of the disk brake assembly and the wheel have been constructed. The automobile hydraulic braking system consisting of two contours is considered. . The mathematical model of the hydraulic braking system is presented, where the flow of liquid and the interaction of liquid with the rigid bodies are taken into account. The flow of fluid in a hydraulic system is described by a system of equations of a hyperbolic type, which is solved by a characteristics method. During the mathematical simulations and natural experimentations the following results were achieved. The systems of equations of dynamic models’ motions are solved by numerical methods. The dynamic characteristics of the braking system of the automobile are obtained. The results of extreme braking tests and calculations are presented.

Analysis of installing ballast water treatment equipment on bulk carriers

In order to protect the world from the invasive species of organisms the cleaning ballast water is required, in other words, discharged water must meet requirements posted by the International Maritime Organization (IMO). The paper provides a comparative analysis of ballast water treatment equipment and its technical parameters. The research has been performed to analyse and assess the effect of the introduced equipment on ship stability, including the effect of its weight, dimensions, performance, price and the efficacy of choice.

Influence of the Secondary Raw Materials on the Mechanical Properties of Multilayer Films

Recycling and usage of secondary raw materials in production is one of the most topical issues. Usage of secondary raw materials is one of the most topical issues in both economic and ecological (environmental) sense. Such a layered film on the market has lower price because secondary raw material prices is significant lower compared with the original material, the PET granules. Currently producing a layered film the middle layer composes up to 50 % of recycled material. In todays market in order to maintain a high level of competitiveness usage of 50 % of recycled materials is inadequate, therefore to use more recycled material amount and in such way to reduce product cost further researches are necessary.