The trade name trauma is located in Bergen a city in the west coast of
norway with long traditions in shipping and maritime business from all is today
the leading supplier of submerged cargo pumping systems to the world tanker
market in year 2000 more than 1400 cargo tankers equipped with from or cargo
pumps a daily crossing the seven seas and safely and efficiently carry and
handle all types of liquefied cargoes in this video we will highlight correct
operation of Rommel cargo pumping systems during loading discharging
stripping and tank cleaning the fram-o system can also incorporate heating
cooling and circulation of the cargo all up to the owners requirements sequence
number one loading the cargo tanks correct operation of pumps and valves is
essential to avoid pressure shocks in the cargo pipeline system during loading
pressure shocks may cause severe damage to pipelines hoses loading arms and
cargo pumps to avoid pressure shocks start the loading slowly and don't open
or close the cargo valve in the system too quickly especially where long
pipelines and high flow rates are involved frommel recommend installing a
separate cargo drop line to obtain a satisfactory loading rate and to make it
possible to bypass the cargo pump during loading
this is a recommended cargo pipe layout in the fromel system if bypassing is not
possible due to valve arrangement use the following procedures to avoid
pressure peaks in the cargo piping during loading keep manifold valve
closed until the cargo reaches the manifold open the manifold valve partly
to fill cargo line on deck open the cargo drop line valve and pump discharge
valve slowly until you reach maximum capacity remember maximum loading
pressure is 8 bar measured at the top of the pump continue to load through the
drop line and the cargo pump if the ship is not equipped with a drop line follow
the same procedure except for operation of the drop line valve most ships today
have an integrated computer system which takes care of control and monitoring of
all activities within the cargo tank section such as pump capacity control
valve control temperature and alleged control if the loading has been stopped
and the cargo valves are closed it's important to restart the loading by
following the same procedure as described earlier
finally some small differences in the loading procedure may apply for a
chemical carrier a product carrier OBO and crude tanker but the main rule is
the same all valves which control the liquid flow should be opened slowly the
time taken for the power operated valve to move from open to shut and from shut
to open must be checked regularly at their normal operating temperatures
sequence number 2 discharging of parcel cargoes start the hydraulic power pack
can increase the hydraulic system pressure if the hydraulic oil
temperature is below 20 degrees centigrade circulate the oil through the
heating valve at maximum 100 bar prior to raising the hydraulics
and pressure to approximately 150 bar start the car go pumped slowly and let
it run with hydraulic pressure forty to fifty bar for approximately one to two
minutes with closed cargo pump valve raise the pumps discharge pressure above
manifold pressure to avoid backflow over pumping and then open the cargo pump
discharge valve increase the hydraulic motor pressure until required this
charge pressure or capacity is achieved if required increase the hydraulic
system pressure follow the same procedure for the next parcel ensure
that enough hydraulic power is available if not the hydraulic pressure will drop
and the capacity head will be reduced the hydraulic system pressure must be
slightly above the highest consumer pressure discharging of homogeneous car
goes parallel pumping running centrifugal pumps in parallel is for
example when discharging the same type of cargo with a number of cargo pumps
through a common shoreline with Fram or cargo pumps this is easy as the frommel
system gives the operator maximum flexibility and stepless speed and
capacity control of each individual cargo pump nevertheless in some cases
we've seen that small misunderstandings in the important relationship between
the pump speed number of pumps running Ilitch a number of size of shorelines
may delay the discharge drastically for optimal understanding from all training
courses in operation and maintenance are arranged worldwide all year round by the
professional trommel training team and there's no doubt the professional
training is a good investment for the ship the ship's crew and the ship owner
the capacity of all centrifugal pumps Berry's very much with the head or the
pumps back pressure if the head is very low for example when pumping just over
the rail the capacity is very large but if the head is very high in goes to
maximum the pump capacity goes to zero in order to have a successful discharge
of homogeneous cargo try to avoid too many bends and tee pieces and never use
valves and pipe diameters that are too small
start the cargo pump using the same procedure as for parcel cargoes always
start the cargo pumps with the discharge valve closed raise the cargo pump
pressure above the shoreline pressure before opening the cargo valve to avoid
backflow over pumping the hydraulic system pressure should be maximum 15 bar
above the highest consumer pressure cargo pump in order to minimize energy
consumption maintenance and wear and tear
cargo pump capacity should be controlled by the pump speed and not by throttle in
the cargo discharge valve or any other valve in the cargo piping system this
can be achieved easily by keeping all cargo controllers in maximum position
and regulating the main hydraulic system pressure until required discharge rate
is achieved if necessary each cargo pump must be balanced
individually by decreasing or increasing cargo pump hydraulic pressure generally
we recommend to run as many pumps in parallel as practical at a reduced
hydraulic pressure rather than just a few pumps at maximum hydraulic pressure
remember two pumps at a hundred percent capacity give the same discharge rate as
four pumps at 50% capacity the advantage is reduced hydraulic system pressure
reduced speed and sound level and increased life time however in some
cases for example when discharging cargo with low specific gravity and very long
shorelines we may have to run the cargo pump with full speed to meet the
discharge pressure at the rail reduced the cargo pump hydraulic pressure to
approximately a hundred bar at the end of discharging or when the pump starts
to lose suction indicated by vibration and hydraulic pressure pulsation this is
to avoid hunting and dry running of the cargo pump sequence number three
stripping at the end of the discharging when the cargo tank is nearly empty
we're in the stripping condition to obtain a best possible stripping result
with a minimum wear and tear on the pump we recommend the following procedure
empty the cargo tank it reduced cargo pump capacity the pump capacity in other
words the hydraulic pressure has to be adjusted according to what type of cargo
you're pumping the cargo specific gravity and viscosity when the cargo
tank is empty close the cargo valve and stop the pump the best stripping result
is obtained with lowest possible back pressure purge and empty the cargo deck
line on this ship the stripping valve for the cargo pump is remotely operated
for easier operation start the cargo pump
locally and increase the pressure to approximately eighty to a hundred bar
open the valve on the stripping line regulate the air inert gas pressure with
the inlet valve and strip the remaining cargo into the deck line until the cargo
tank and cargo pump is empty close the stripping valve stop the purging and
stop the cargo pump
repeat the stripping sequence if necessary to sum it all up we will
highlight the four main steps schematically step one end of the
discharging the cargo pump is running at reduced speed cargo valve and manifold
valve are open until the cargo tank is empty step 2
purging of the cargo deck line when the cargo tank is empty close the cargo
valve and stop the pump empty the cargo deck line by purging with inert gas
close the manifold valve step 3 relieving the pressure in the cargo deck
line open the small stripping valves on cargo Punk deck line to minimize back
pressure in the line step 4 stripping start the cargo pump locally and
increase the pressure to approximately 80 to 100 bar connect the air in a gas
supply to the cargo pipe and strip out the cargo through the small stripping
pipe purge until the cargo tank and pipe stack is empty close the stripping valve
and stop the pump by following this procedure you will achieve an excellent
stripping results and remember when the discharge and stripping operation are
completed purge the cargos pump cofferdam sequence number four tank
cleaning to keep a dry tank top and still avoid
dry running during tank cleaning the tank cleaning machines capacity flow
into tank and the cargo pumps capacity flow out a tank must be equal reduce the
cargo pomp hydraulic pressure until the capacities are balanced before tank
cleaning is finished closed the pumps discharge valve and open the stripping
valve to allow an increase in water level run the pump at approximately a
hundred and ten bar against the closed cargo pump discharge valve for one to
two minutes to clean the cargo pump remember to flush the pump and tank with
fresh water if sea water has been used for tank cleaning by following these
instructions you will achieve an energy efficient discharge no pressure shocks
during loading and minimal wear and tear on the cargo pumps during stripping and
tank cleaning in other words lower operation and
maintenance costs for the ships as well as for the owners