Framo hydraulic cargo pumping system/Cargo pumping system in tanker vessel/FRAMO SYATEM

The framo hydraulic cargo pumping system is designed for a flexible and safe cargo and tank cleaning operation on ships. It consists of one hydraulic motor driven cargo pump installed in each cargo tank, ballast pumps, tank cleaning pumps, portable pumps and other consumers, all connected via a hydraulic ring line system to a hydraulic power unit as shown in figure below. The submerged cargo pump is a single stage centrifugal pump with the impeller close to the tank top, giving a good pumping performance of all kinds of liquids and with excellent stripping performance. The hydraulic section is surrounded by a cofferdam that completely segregates the hydraulic oil from the cargo.The hydraulic power unit consists of electric motor and/or diesel engine driven hydraulic power packs, where the hydraulic pumps are of axial piston type and swash plate design with variable displacement. The pump displacement is hydraulically controlled via the pressure regulator on each pump and by this system, the oil delivery from the hydraulic pumps will always be the same as the oil consumption for the hydraulic motors. To control and limit the speed of the motor, a control valve is fitted for each motor.
To keep the hydraulic oil clean and hydraulic oil temperature within desired range, a full flow filter and cooler are installed in the main return line. To regulate the oil temperature, a cooling water inlet valve is controlled from the framo control system. To prevent impurities from entering the hydraulic system, the system is also pressurized (2-6 bar) when not in operation. Depending on the installation, this is done by a jockey or feed pump.
The discharge from all cargo, ballast and other pumps connected to the system may be remotely controlled from framo control panel, vessel’s integrated control system (ICS) or locally at each pump via the control valve. The portable pump is controlled locally at the pump via the control valve. The equipment is manufactured in Norway ‘Framo’ facility and the most important benefits of the system are:
Segregation of cargoes for vessel’s safety and the environment.
Maximum transport volume.
Efficient stripping and tank cleaning.
Hydraulic system without any electrical power equipment in cargo area.
Automatic regulation of power needed and impossible to overload.
The Framo cargo pumping system is controlled by a Programmable Logic Control (PLC) installed inside the control panel. The PLC is programmed by Framo and provides the logic for safe operation of the system.All alarm inputs, except “Wear indication” are normally closed, meaning that the system is built up on normally closed contacts. Hence if a contact opens or there is a loose wire, an alarm condition occurs, i.e. FAIL TO SAFE.
The alarms are divided into two groups:
a) Shut down
b) Alarm for indication (pre-warning) only
Each alarm is indicated with a flickering light and an acoustic signal. The “Horn silence” button must be operated before it is possible to confirm the alarm by the “Acknowledge” button.
Group a) alarms: The “Reset” button must be operated to clear the alarm.
Group b) alarms: Automatic reset
POWER SUPPLY
Most hydraulic system control panels are supplied via two separate power feeders, main and back-up. In case of failure to main feeder, automatic change-over to back-up will take place. For increased availability and simplified trouble shooting, the control system is electrically divided into separate sub-systems. Each sub-system has its own 24VDC power supply. Failure in one system is not likely to interfere with other systems.
The feeders and DC power supplies are monitored by relays provided with status lamps. The lamps illuminate when corresponding feeder/ supply is in good condition. A failure on any of the feeders/ supplies or short circuit will generate a potential free (dry contact) power failure alarm to the engine control room in addition to alarm at the control panel.
Reference:
SERVICE MANUAL FOR CARGO PUMPING SYSTEM by Framo