Ship Bilge Research Articles

New technology for ship bilge and oily water separation

AbstractBilge and oily water (BOW) during vessel's operation are the most large‐tonnage type of waste and for their treatment all ships, in accordance with international regulatory requirements, have to be equipped with special equipment—oily water separators. At sea vessel's operating conditions three main directions of BOW cleaning are now used: physical, chemical and biological. The analysis of BOW separation methods based on these three directions has shown that it is very difficult to obtain secondary petrochemical products. In the article authors offer a new method for BOW separation which is based on the use of a hydrodynamic process of supercavitation with artificial ventilation of the cavitational cavern. With local origin in the flow of a supercavitating cavern, there will always be saturated water vapor inside of it. The process of permanent water vapor selection from the cavern will ultimately contribute to the production of highly concentrated mixture of secondary petroleum products from initial mixture of BOW. During the study of BOW separation process it was found that decreasing of the working pressure inside the working chamber of the cavitation separator have to be always compensated by an increase in the temperature of the processed multiphase flow.

ФИЗИКО-ХИМИЧЕСКИЕ ПОКАЗАТЕЛИ СУДОВЫХ ЛЬЯЛЬНЫХ ВОД

To destabilize finely dispersed oil-water emulsions and, as a result, to increase the efficiency of flotation treatment
 of ship bilge water, a reagent treatment method is used. The limiting factors in choosing a flocculant for
 preliminary reagent treatment of bilge waters should include the physicochemical characteristics of the oilwater
 solution. The paper presents the results of a study of the following physicochemical parameters of a
 solution of ship's bilge waters: the dispersed composition of contaminants, the charge of contaminant particles,
 kinematic viscosity, density and surface tension of the solution

Off-shore purification of oil water during the operation of inland navigation vessels

This article is devoted to the problem of protecting reservoirs from pollution by petroleum products contained in ship's bilge water formed during the operation of inland navigation vessels. Despite the current experience, this problem has not yet found any effective solution. The ship's installations used do not always reliably provide the required degree of purification, and, in addition, many inland navigation vessels do not have the possibility of placing installations for the purification of oil bilge water. It is shown that for these reasons, the most effective solution to the problem under study is the use of a complex of technical means of off-court cleaning oil bilge water. At the same time, the article proposes to represent all the actions that the oil bilge water undergoes at the same time as the technology of the process of its movement. It is also shown that the content of this technology will be different for different sections of waterways. The factors that will determine the specified content of the oil bilge water movement technology have been established. This approach makes it possible to ensure the required purification of alloil bilge water that is formed in the considered area of waterways at the lowest cost and while ensuring navigation safety.

Ship bilge water (pathway vector)

This datasheet on Ship bilge water (pathway vector) covers Identity.

Ultimate Strength of Container Ship Bilge Panels Subjected to Axial Compression Combined with Bending and Lateral Pressure

Ultimate Strength of Container Ship Bilge Panels Subjected to Axial Compression Combined with Bending and Lateral Pressure

Experimental Investigation into the Effect of Roll Amplitude on Roll Damping

An in-house large eddy simulation (LES) code has been developed in the previous study. In order to validate the code for simulation of roll motion, effect of roll amplitude on forced roll damping is experimentally investigated in a circulating water channel at Shanghai Jiao Tong University (SJTU). KRISO very large crude carrier 2 (KVLCC2) is taken as a target ship, and a model with a scale of 1: 128.77 is manufactured. Tests are carried out for the ship model at shallow draft with frequencies around its natural roll frequency, where natural roll frequency is attained via free roll decay. Six forced roll tests with roll amplitudes ranging from 1° to 4° are performed experimentally, and three forced roll motions are simulated with the in-house LES code for middle section of the ship model. Discrepancies between the computed roll damping coefficients and the ones from forced roll tests are quite small. By means of particle image velocimetry (PIV), velocity fields in the vicinity of the ship model, and generation and evolution of vortices near the ship bilge are measured in detail. It is shown that roll amplitude has a significant effect on the vortex behavior, and therefore on the magnitude of roll damping coefficient. Further experimental and numerical investigation into roll motions with large amplitudes is planned.

Study on dynamic characteristics of double cylinder double acting bilge pump transmission

In view of the complex structure of the ship bilge pump, the excitation source in the process of work is difficult to accurately determine the fault condition of the bilge pump through the vibration test data. Based on the theory of multi - body dynamics, rotor dynamics and electrical mechanics, the kinematics and kinetic equations of the bilge pump drive are established, and the dynamics, kinematics and vibration characteristics of bottom Pump drive analysis of the cabin is carried out. The frequency of the excitation force corresponding to the transmission mechanism is deduced, and the frequency of the excitation force of the main transmission is calculated.

High-flux thin-film nanofibrous composite ultrafiltration membranes containing cellulose barrier layer

A novel class of thin-film nanofibrous composite (TFNC) membrane consisting of a cellulose barrier layer, a nanofibrous mid-layer scaffold, and a melt-blown non-woven substrate was successfully fabricated and tested as an ultrafiltration (UF) filter to separate an emulsified oil and water mixture, a model bilge water for on-board ship bilge water purification. Two ionic liquids: 1-butyl-3-methylimidazolium chloride and 1-ethyl-3-methylimidazolium acetate, were chosen as the solvent to dissolve cellulose under mild conditions. The regenerated cellulose barrier layer exhibited less crystallinity (determined by wide-angle X-ray diffraction, WAXD) than the original cotton linter pulps, but good thermal stability (determined by thermal gravimetric analysis, TGA). The morphology, water permeation, and mechanical stability of the chosen TFNC membranes were thoroughly investigated. The results indicated that the polyacrylonitrile (PAN) nanofibrous scaffold was partially imbedded in the cellulose barrier layer, which enhanced the mechanical strength of the top barrier layer. The permeation flux of the cellulose-based TFNC membrane was significantly higher (e.g. 10×) than comparable commercial UF membranes (PAN10 and PAN400, Sepro) with similar rejection ratios for separation of oil/water emulsions. The molecular weight cut-off (MWCO) of TFNC membranes with cellulose barrier layer was evaluated using dextran feed solutions. The rejection was found to be higher than 90% with a dextran molecular weight of 2 000 KDa, implying that the nominal pore size of the membrane was less than ∼50 nm. High permeation flux was also observed in the filtration of an emulsified oil/water mixture as well as of a sodium alginate aqueous solution, while high rejection ratio (above 99.5%) was maintained after prolonged operation. A variation of the barrier layer thickness could dramatically affect the permeation flux and the rejection ratio of the TFNC membranes, while different sources of cellulose, ionic liquids, and non-woven supports did not. As ionic liquids can be recycled and reused without obvious decomposition, the chosen method also demonstrates a benign pathway to fabricate the cellulose barrier layer for other types of membranes.

ENHANCING SAFETY IN SHIP'S CRITICAL SYSTEMS USING MARKOV MODELING

The current study uses reliability models for the improvement of the operation of a ship's "bilge — water separator" system. A "bilge-water separator" is a mechanism which cleans and inspects the ship's bilge water before it is discharged into the sea. Homogeneous continuous time Markov models have been used to record and estimate possible hazards and system failures in two different operational scenarios. If the photocell unit of the system fails, the ship may cause severe sea pollution. This study attempts to estimate the probability of sea pollution based on empirical data. In addition, the results of the model are compared with those of a system in which a second metering unit is added in an effort to to find out if this alteration improves the systems' efficiency.

Microbial characterization and hydrocarbon biodegradation potential of natural bilge waste microflora.

Shipping operations produce oily wastes that must be managed properly to avoid environmental pollution. The aim of this study was to characterize microorganisms occurring in ship bilge wastes placed in open lagoons and, particularly, to assess their potential to degrade polycyclic aromatic hydrocarbons (PAHs). A first-order kinetic was suitable for describing hydrocarbon biodegradation after 17 days of treatment. The calculated rate constants were 0.0668 and 0.0513 day(-1) with a corresponding half-life of 10.3 and 13.5 days for the aliphatic and aromatic hydrocarbon fractions, respectively. At day 17, PAH removal percentages were: acenaphtylene 100, fluorene 95.2, phenanthrene 93.6, anthracene 70.3, and pyrene 71.5. Methyl phenanthrene removals were lower than that of their parent compound (3-methyl phenanthrene 83.6, 2-methyl phenanthrene 80.8, 1-methyl phenanthrene 77.3, 9-methyl phenanthrene 75.1, and 2,7-dimethyl phenanthrene 76.6). Neither pure cultures nor the microbial community from these wastes showed extracellular biosurfactant production suggesting that the addition of an exogenously produced biosurfactant may be important in enhancing hydrocarbon bioavailability and biodegradation. DNA analysis of bilge waste samples revealed a ubiquitous distribution of the nahAc genotype in the dump pools. Although almost all of the isolates grew on naphthalene as sole carbon source, only some of them yielded nahAc amplification under the experimental conditions used. The variety of PAHs in bilge wastes could support bacteria with multiple degradation pathways and a diversity of catabolic genes divergent from the classical nah-like type.

Spreadsheet modeling of optimal maintenance schedule for components in wear-out phase

Abstract This paper addresses a method for determining the optimum maintenance schedule for components in the wear-out phase. The interval between maintenance for the components is optimized by minimizing the total cost. This consists of maintenance cost, operational cost, downtime cost and penalty cost. A decision to replace a component must also be taken when a component cannot attain the minimum reliability and availability index requirement. Premium solver platform, a spreadsheet-modeling tool, is utilized to model the optimization problem. Constraints, which are the considerations to be fulfilled, become the director of this process. A minimum and a maximum value are set on each constraint so as to give the working area of the optimization process. The optimization process investigates n -equally spaced maintenance at an interval of Tr. The increase in operational and maintenance costs due to the deterioration of the components is taken into account. This paper also performs a case study and sensitivity analysis on a liquid ring primer of a ship's bilge system.

Biosurfactant-enhanced degradation of residual hydrocarbons from ship bilge wastes

The use of Bacillus subtilis O9 biosurfactant (surfactin) and of bioaugmentation to improve the treatment of residual hydrocarbons from ship bilge wastes was studied. A biodegradation experiment was conducted in aquaria placed outdoors under non-aseptic conditions. Three treatments were examined: culture medium plus bilge wastes, bioaugmentation with microorganisms from bilge wastes, and bioaugmentation plus biosurfactant. Samples were analyzed for viable counts, aliphatic and aromatic hydrocarbon concentrations, n-C17/pristane and n-C18/phytane ratios. While the addition of biosurfactant stimulated hydrocarbon degradation, bioaugmentation did not produce any remarkable effect. At day 10, the remaining percentages of aliphatic and aromatic hydrocarbons in aquaria, which received biosurfactant, were 6.8 and 7.2, respectively, while it took 20 days to reach comparable results with the other treatments. The biosurfactant did not affect the preferential biodegradation of n-C17/pristane and n-C18/phytane. This biosurfactant, which can be produced in a relatively simple and inexpensive process, is a promising alternative in the optimization of hydrocarbon waste treatment. Journal of Industrial Microbiology & Biotechnology (2000) 25, 70–73.

4647371 Oil/water disperser device for use in an oil content monitor/control system

An oil content monitor/control unit system including an oil/water disperserevice is configured to automatically monitor and control processed effluent from an associated oil/water separator so that if the processed effluent exceeds predetermined in-port or at-sea oil concentration limits, it is either recirculated to an associated oil/water separator via a ship's bilge for additional processing, or diverted to a holding tank for storage. On the other hand, if the oil concentration of the processed effluent is less than predetermined in-port or at-sea limits, it is discharged overboard. The oil/water disperser device is configured to break up any oil present in the processed effluent into uniform droplets for more accurate sensing of the oil-in-water concentration level thereof. The oil/water disperser device has a flow-actuated variable orifice configured into a spring-loaded polyethylene plunger which provides the uniform distribution of oil droplets.

Breaking emulsions in Navy bilge collection and treatment systems

The new bilge waste collection and treatment system, which serves as the collector, transporter, and gravity separator for ship's bilge waste, was a suitable medium for the application of chemical demulsification techniques. Chemical demulsification methods were especially suitable for emulsified oily wastes that are reluctant to separate into the constituent phases. Laboratory tests indicated that certain quaternary ammonium compounds were effective in breaking 5% oil-in-seawater emulsions over a 20-h period at temperatures ranging from 4 C to 45 C. The demulsifier concentration required to break the emulsions generally ranged from 1% to 2% at 4 C to 0.1% to 0.2% at 45 C. At the low temperature the oil concentration in the separated water ranged from 100 to 500 ppm; at the higher temperature no more than 55 ppm was observed with most oil level readings of the order of 25 ppm or less. The demulsifiers were useful in breaking emulsions of Navy Distillate, used motor oil, turbine oil, and bilge wastes containing unknown oil mixtures. A field demonstration supported the laboratory tests.

Thin-layer chromatographic technique for identification of waterborne petroleum oils

A thin-layer chromatographic procedure for the identification of waterborne petroleum oil pollutants for use in either the laboratory or the field is developed. Aromatic and polar compounds are removed from the oil sample by a liquid-liquid extraction with acidified methanol. The extract is then chromatographed on a silica-gel thin-layer plate. Separated components are detected by their fluorescence under long and short wave ultraviolet light. Iodine staining is also used to visualize unsaturated, nonfluorescing compounds. This procedure is successfully applied to ''fingerprinting'' gasolines, kerosenes, diesel oils, heavy fuel oils, lubricating oils, and ship bilge oils.