e air passing to pumps on tankers there is widely used pumping with vacuum tanks application. The essence of this method is in that pumps pump fuel not separately from each tank but from one hermetically closed in which vacuum is kept; from the rest of tanks the product passes into the vacuum tank due to pressure difference. The tank 1 adjacent to the pump room is used as vacuum one (fig.4). The tank is equipped with additional receiver 3, connecting it with the pump 4, and also sluices valves on gas eliminating and other pipelines, supplied to the tank from the deck.pumping start the vacuum tank is disconnected from all pipelines and checked for sealing reliability. Then through the additional receiver 3 the petroleum product is pumped out the tank approximately on 2/3 of filling height, at this in the tank is created vacuum equaling 0,035 MPa. Thereafter pumping continues, the vacuum tank is connected to another cargo tank for what the corresponding sluice valve 2 is opened on the cargo pipeline. Transfer to a next tank, as pumping goes, is executed by a usual switching of receiving sluice valves.vacuum value in the vacuum tank is to be set considering the petroleum product saturated vapors pressure at pumping temperature. If P y gt; P vac1 the petroleum product starts boiling. Vacuum tanks application allows reducing pumping time by 20% .of sand spits and small depths in rivers, especially in summer period, requires application of tankers with a minimal draught. The minimal draught value, basing on conditions of engines regular operation, can be brought to 1,25m (the carrying capacity makes up nearly 600 ton in this case).
barges (fig.5) are also widespread in river transportations. Barges carry huge loads but have to be propelled with some motor vessel.
Means of fuel discharge to oil carriers
In case if an oil carrier doesn t have own pumps the movable pump station can be used for fuel discharge to reservoirs.pump stations are also widespread in places, where construction of stationary pump station is not economically reasonable.pump stations are applied on riverside tank farms with considerable water level fluctuation (around 5 m). In such conditions riverside pump stations can pump fuels from oil tankers at low water. Application of floating stations mounted on barges or pontoons, moored to an oil tanker side, allows realizing pumping independently from water level.
. 6 floating pump station
pump stations are usually equipped by cargo pumps for oil products pumping, stripping pumps for oil tanker reservoirs cleaning, ballast pumps for filling and emptying of ballast sections and fire pumps. Floating pump stations connect to riverside pipelines by flexible hoses or globe joint pipes.of floating pump station:
· Rises and lowers together with the water level;
· Is equipped by submersible pumps which are permanently under water;
· Operates in a totally automated mode;
· Is equipped with fish protective devices.the navigation period on the Lena River makes up around 1/3 of year I suppose it s better to have an easy demountable movable pump station. Withal, the floating pump station is the most productive variant of those.
Means of fuel shipment to oil carriers realizing of liquid products loading operations between farm tanks and tankers standpipes are used.standpipe is the basic loading equipment, which is mounted on the loading bay and provides cargo, ballast and bunker pipelines connection to tanker.
.7 A standpipe
consists of a supporting pipe, a hinged arm, current collecting systems with auxiliary counterweights for keeping balanced the whole sleeve and standpipe non-operating position fixation lock.standpipe is balanced in all positions by two counterweights and a current collector. Shipboard and riverside pipe sections as well as whole unit rotation in a vertical plane is managed due to hydraulic cylinders, operated in loco or remotely.the standpipe is connected to a tanker the hydraulic cylinders automatically switch to a fail-safe operation, which allows the standpipe to follow the tanker, considering tossing, wind, stream and tides.the top of the standpipe vertical pipe there are mounted two cargo arms for rotation in horizontal and vertical planes and a vacuum breaker to prevent the liquid spill on the tanker deck (fig.7).
Standpipes are mounted on the oil mooring loading bay in group of 3-6 pieces.standpipe connecting to the tanker suction manifolds, loading, unloading and disconnection control is performed by radio, as well as from the control center, l...
