Bilgewater is created by leaks of salt water, cooling water, fuel oil and lube oil, by the dewatering of sedimentation and sludge tanks, by the draining off of various cleaning processes and also by particles of soot and dirt.
| Every ship, whether it is a container ship, an oil tanker or a freighter, produces bilgewater which is disposal problem. The IMO specifies that bilgewater may be discharged into the sea only if its residual oil content is below 15 ppm. At the same time, the oil recycled from the separation process can be reused for a variety of purposes. Oil recycled out of the separation process can be reused as fuel oil, for example. Recovered lube oil can be used as a fuel to generate heat. |
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There were two methods of the sludge disposal, such either to incinerate it on board or to dispose of it on shore. Incineration is an expensive process because the sludge has to be dewatered by evaporators and then mixed with precious diesel oil to generate a combustible fuel. Disposal on land is also associated with considerable costs, as the sludge has to be transported to a waste disposal site which in turn has to be paid for. The specially developed separator uses dewatering and oil recovery processes to reduce the volume of sludge. At the same time, valuable fuel oil is recovered, the bilgewater system is freed from oil residues.
Sea Water Desalination
Storing large quantities of fresh water not only expensive but also takes up a large amount of space. Desalination is based on the evaporation principle: sea water which has been filtered through a coarse mesh is evaporated in a heat exchanger plate stack made of titanium to precipitate salt and impurities. A further plate stack condenses the steam into drinking water. A salt measuring cell now checks residual salt content which is usually below 4 ppm. If a value below this is reliably maintained, the fresh water can be passed into a storage tank and subjected to further treatment in the form of UV sterilization. A re-hardening filter then finally returns enough hardness to the fully demineralized water to make it potable for humans.
| Answer the following questions: 1.What is bilgewater/sludge? 2. How is the bilgewater treated? 3. What is the way of sludge treatment? 4. How can the sludge be disposed? 5. Describe the process of desalination. |
Vocabulary
Alkalinity is the alkali concentration or alkaline quality of a substance that contains alkali.
The ash content is related to the amount of inorganic material in the fuel.
The carbon residue of a fuel is the tendency to form carbon deposits under high temperature condition in an inert atmosphere, and may be expressed as either Conradson Carbon Residue (CCR) or Micro Carbon Residue (MCR). The maximum limit of carbon residue content in fuel is 22 %.
Detergent is a synthetic cleaning agent or substance.
Density is the relationship between mass and volume at a stated temperature.
The flash point of the liquid is the lowest temperature at which sufficient vapor is given to produce a flash on application of a flame under specified test conditions.
Oiliness is the oil’s ability to adhere to the surfaces such as white metal bearings.
Oil additives are chemical compounds that improve the lubricant performance of base oil. The manufacturer of many different oils can utilize the same base stock for each formulation and can choose different additives for each specific application. Additives comprise up to 5% by weight of some oils.
The pour point is the lowest temperature at which a marine fuel oil can be handled without excessive amounts of wax crystals forming out of solution. At a lower temperature the fuel will gel, thereby preventing flow.
The specific gravity of HFO is its ratio to the density of water at a specified temperature. Bunker oil HFO ranges between 0.95-1.03
Viscosity is a measurement of the resistant of a liquid to shear or flow and is measured in Centistokes (CST) with a quoted reference temperature.
Volatility is the ability of the oil to ignite due to a low flash point.
Vocabulary Section
heavy fuel oil (HFO) – мазут marine diesel oil (MDO) – дизельное топливо
sulfur content – содержание серы
sludge – осадок, шлам
density - плотность specific gravity – удельная плотность
viscosity - вязкость
to be of concern – иметь значение
flash point – температура вспышки
pour point – температура застывания, температура потери текучести нефти
wax formation – парафиновая пленка (воск)
treatment - обработка intermediate - промежуточный
settling tank –отстойная цистерна
day =storage=service tanks –расходные цистерны
to take into account = to take into consideration – принимать во внимание
ash – зола, пепел soot – кокс, сажа, нагар (топливо)
carbon residue – коксовое число (остаток), нагар
contaminant = impurity (impurities) – загрязняющее вещество, примесь
to undergo - совершать, выполнять
to dissipate - рассеивать to combat – противодействовать
friction - трение wear and tear – износ и разрыв
volatility – испаряемость, летучесть
alkalinity – степень насыщения щелочью, щелочность
detergent – моющая присадка (очищающий агент, препятствующий схватыванию)
oiliness – маслянистость, смазочные качества
boundary lubrication – смазка тонким слоем, граничная смазка
film thickness – толщина пленки
constituents - компоненты
to slide - скользить
decomposition - расслоение
oil sump - маслоотстойник
ageing – окисление (топливо, масло)
steam coils – паровые змеевики
Bilgewater – трюмная вода
sedimentation – отложение осадка, процесс отстоя
disposal – утилизация отходов
Recovered – регенерированное (топливо, масло)
Backflush – промывка обратным потоком
precious - точный
site – здесь: место утилизации мусора
coarse mesh – сетка с крупными отверстиями для грубой очистки
plate stack – блок пластин теплообменника
to precipitate – отстаивать, давать осадок
UV sterilization – стерилизация УФ излучением
re-hardening filter – фильтр восстановления минерального состава деминерализованной или дистиллированной воды
additives – присадки для более эффективной работы (топливо и масло)