What is the working principle of fuel oil separator?

The working principle of fuel oil separator is based on centrifugal force. An electromotor supplies the power to the fuel oil separator. The electromotor rotates a bowl spindle by a worm wheel. The bowl spindle rotates the separator bowl where light components such as oil and heavier components such as water and sludge are separated by using centrifugal force of centrifuges. The lighter component is pushed inwards while heavier components are pushed outwards through the sludge outlet nozzles.

 

What are two operating modes of fuel oil separator?

A fuel oil separator can operate as a purifier or as a clarifier.

 

How does a purifier work?

A purifier separates three phases: solid particles (sludge) and two insoluble liquids (oil and water). There is an oil-water interface at the bowl discs. For correct oil-water interface position the gravity disc is used. A purifier needs to be filled completely with sealing water to prevent the oil to leave from the water outlet. A purifier is mainly used when sludge has to be separated from oil together with small quantities of water from sludge.

 

How does a clarifier work?

A clarifier separates two phases: solid particles (sludge) from a liquid (oil). In the clarifier mode the clarifier disc is fitted instead of gravity disc. There is no sealing water and no oil-water interface. The water outlet is simply blocked by level ring. In case there is some water it will be removed together with the sludge. This method is mostly used for residual fuel or after the purifier in the fuel line.

 

What is marine oily water separator used for?

Oily water separator is used to clean bilge water on board the vessel. It separates oil from bilge water before it is pumped overboard.

 

What does the oily water separator consist of?

The oily water separator consists of catch plates inside a separating vessel and an oil collecting chamber.

 

How does oily water separator work?

The oily water separator works on the principle of coalescing small oil droplets in the water to form larger oil drops. When the oil drops become large enough, the oil drops float up and collect at the top of the vessel. The water remains at the lower portion and is pumped overboard. The oil layer is pumped into an oily bilge tank which can be pumped out at an oil collecting facility when the ship arrives at a port.

 

What is an air compressor?

An air compressor is a device that converts power (usually from an electric motor or a diesel engine) into kinetic energy by compressing and pressurizing air.

What is an air compressor used for on board?

On a ship an air compressor is used to compress air and store it in tanks for various uses from simple processes such as cleaning and drying of filters to tasks such as starting the auxiliary and main engines of the ship.

 

What types of air compressors do you know?

Compressors are classified in many ways. By classification based on the principle of operation there are such types of air compressor as: 1) positive displacement and 2) dynamic compressors. Positive displacement compressors can be further divided into reciprocating (piston or diaphragm) and rotary (screw, vane, lobe or scroll) compressors. Under the dynamic compressors, we have 1) centrifugal compressors and 2) axial flow compressors.

 

What air compressors are used on board?

On the basis of application, different air compressors are kept for a particular usage. Normally, air compressors on board ships are: main air compressor, topping up compressor, deck air compressor, emergency air compressor.

 

What are their purposes?

Main air compressor is used for supplying high pressurised air for starting of main and auxiliary engines.

Topping up compressor takes up the lead to cover up for the leakage in the system.

Deck air compressor is used for deck use and as service air compressor and might have a separate service air bottle for the same.

Emergency air compressor is used for starting auxiliary engine at the time of an emergency or when the main air compressor has failed for filling up the main air receiver.

 

What is a pump?

A pump is a machine used to raise liquids from a low point to a high point.

 

What characteristics does each pump have?

Every pump has a power end, which may be a steam turbine, a reciprocating engine or an electric motor, and liquid end where the liquids enters and leaves the pump. The suction head means the pressure of the liquid entering the pump, or the difference in the level of liquid with respect to the level of the pump on the suction side. The discharge head means the pressure of the liquid leaving the pump, or the level of liquid with the respect to the level of the pump on the discharge side.

 

What are the main classes of pumps in marine use?

There are three main classes of pumps in marine use: displacement, axial flow and centrifugal. Displacement pumps can be either reciprocating or rotary.

 

What is a function of centrifugal pumps?

Centrifugal pumps are widely used on board ship for pumping non-viscous liquids such as sea water and fresh water.

 

What is a working principle of centrifugal pump?

The centrifugal pump utilizes the throwing force of a rapidly revolving impeller. The liquid is drawn in at the center of the impeller and is discharged at the outer rim of the impeller.

 

What is a function and working principle of reciprocating pump?

The reciprocating pump moves liquid or gas by means of a piston or plunger which goes back and forth or up and down within a cylinder containing a suction valve and discharge valve.

 

What is a function of rotary pumps?

Rotary pumps are particularly used for pumping oil and other heavy viscous liquids.

 

What is a working principle of rotary pumps?

All rotary pumps work by means of rotating parts, which trap the liquid at the suction side and force it through the discharge outlet.

 

What types of rotary pumps do you know?

Classification of rotary pumps is generally made according to the type of rotating elements: screw, gear, vane, lobe and axial plunger rotary pumps.

 

47. How to change the ship’s direction?

The direction is changed by steering gear. It is the equipment provided on ships to turn the ship to left (Port side) or to right (Starboard side) while in motion.

 

48. Where is steering gear situated?

The whole steering gear arrangement should be kept in a separate compartment, known as the steering gear compartment/room.

 

49. What are the main components of steering gear?

Complete Steering Gear system consists of three main parts namely: Telemotor, Control Unit and Power Unit.

 

50. What is a turbocharger?

A turbocharger or turbo is a device used to allow more power to be produced for an engine.

 

51. What for is the turbocharger installed?

The turbocharger converts waste energy from exhaust gases into compressed air, which it pushes into the engine. This allows to improve efficiency of the combustion process, increasing power of the engine.

 

52. Can you name the main components of turbocharger?

A turbocharger consists of a turbine and compressor connected by a common shaft supported on a bearing system.

 

53. Does the use of turbochargers have any advantages?

Engine with turbocharger provides better combustion process, which results not only on increase of power, but also on decrease of fuel usage and toxic gases. It also produces less noise while operation.

 

What is boiler?

A metal container or a tank for generating steam under pressure in a steam engine.

 

55. Describe simplified boiler arrangement.

The process of steam generation starts when water enters the steam drum. The water enters drum through the tubes surrounded the furnace. The feed water gets heated when passes through the tubes. The steam produced in the steam drum is known as saturated or wet steam. To make this steam usable, it is first dried and heated with the help of the superheater located within the boiler. Once all the moisture content is removed from the steam, the superheated steam can be supplied to other systems.

 

56. What are the types of boilers?

Watertube boiler, firetube boiler, waste-heat boiler, natural water circulation type boiler, forced water circulation type boiler, combine boiler plant, auxiliary boiler.

 

57. What is the difference between watertube and firetube boilers?

In firetube boiler water circulates in tubes heated externally by the fire. In watertube boiler the gases of combustion pass through the tubes that are surrounded by water.

 

58. What is the function of furnace?

A furnace provides a constant burning.

 

59. What may be done to increase efficiency of the boiler system?

To provide the efficient combustion, a certain set of conditions is necessary: maintenance of high furnace temperature, ensuring of continuous oil-fuel and air supply, removal products of combustion.

 

60. What types of propulsion plants can you name?

There are gas and steam turbine engines, diesel engines, nuclear power plants.