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drilling system

Trixie Marsya Rofifah
The Centrifugal Governor or Flyball Governor was invented by James Watt.
What is flyball governor? A flyball governor is a specific type of governor with a
feedback system that controls the speed of an engine by regulating the flow of
fuel or working fluid, so as to maintain a near-constant speed. Flyball governer
uses the principle of proportional control.
Flyball governer composed by two balls of equal mass, which are attached to
the arms as shown in Figure. These balls are known as fly balls. The balls
revolve with a spindle, which is driven by the engine through bevel gears.
Figure 1
The upper ends of the arms are pivoted to the spindle, so that the balls may
rise up or fall down as they revolve about the vertical axis.
The arms are connected by the links to a sleeve, which is keyed to the spindle.
This sleeve revolves with the spindle, but can slide up or down. The balls and
the sleeve rises when the spindle speed increases, and falls when the speed
decreases. In order to limit the travel of the sleeve in upward and downward
directions, two stops, S are provided on the spindle. The sleeve is connected by
a bell crank lever to a throttle valve. The supply of the working fluid decreases
when the sleeve rises and increases when it falls.
The centrifugal governor has various components inside it that allow it to keep
the speed of an engine stable, below are the parts of the centrifugal governor.
Figure 2
The parts shown in the image are as follows –
The sliding collar: this can move up and down on the main shaft
3 bearings: these allow the gold parts to open in a scissor-like motion
main shaft: this is the main shaft upon which everything else rests
idle speed plate:this stops the engine going to slow, if this plate was not
here the centrifugal governor could cut the fuel supply off from the
weighted balls: these rise under centrifugal motion as the whole system
begins to rotate
Pulley to engine: there is a belt attached to this pulley which goes
directly to the engine, therefore when the engine speeds up or slows
down, the centrifugal governor follows suit
Other than that, flyball governor has pivot as the controller, steam as the
plant, flyball as the censor, butterfly valve as the actuator. The input and the
output of this control system is control how much speed that the engine
The governor can move in two directions, rotary motion and up and down
Figure 3
So, as we can see, Flyball Governor is a really simple and useful to increase the
efficiency and efficient on Steam Engine. It is really important to helps our lives
because this type of governor is needed for many kind of industries such as
textile, tableware, coal mining, steel mills, etc. These kind of industries
required a stable engine speed from their steam engines to run effectively and
As soon as this governor was introduced it was received by all industries. In
fact it has been used ever since, it can still be found in modern car engines, jet
engines and many other rotating machines. This kind of governor very useful
too in maritime industries. On modern propellers, the centrifugal governors
senses shaft RPM and adjusts the pitch of the blade to vary the torque load on
the engine.
Trixie Marsya Rofifah
A governor, or speed limiter, is a device used to measure and regulate the
speed of a machine, such as an engine. Governor divided by two types,
mechanical governor and electronic governor. An Electronic governor provides
engine speed adjustment from no-load condition to full load. Earlier,
mechanical governors were used, but with the advancement of electronic
components, the control features of governors have become much more
flexible and this type of governor more used for speed control.
Figure 1
Electronic governor senses this engine speed and converts into electrical
pulses or frequency and sends it to electronic control unit. Electronic control
unit senses these pulses or frequencies and controls the actuator which in turn
controls the fuel injecting pump. Thus at various loads or speeds the electronic
governor works efficiently.
These governors typically are retrofitted to applications that now require a
governor. They pick up the engine speed from the flywheel ring gear’s teeth
and control it electronically. If the engine is running at some intermediate
speed between idling and maximum, but at less than full load, any change in
load will cause a speed change. Electronic governor senses this engine speed
and converts into electrical pulses or frequency and sends it to electronic
control unit. Electronic control unit senses these pulses or frequencies and
controls the actuator which in turn controls the fuel injecting pump. Thus at
various loads or speeds the electronic governor works efficiently.
Figure 2
The electronic controller has different modes of operation to implement various
functions. These include:
1. Detecting the starting of an engine and subsequently directing the fuel supply.
2. Suppressing the smoke generated by the engine as its speed increases.
3. Adjusting the droop percentage. A detailed explanation of the droop
percentage is given below.
4. Remote speed control.
5. Idle speed operation: It provides fixed speed control over the entire torque
capacity of the engine.
6. Maximum speed control: It is used to eliminate over speeding of the engine
Figure 3
What are the components of electronic governor control system? From figure
above, we know that electronic governor has governor as controller, fuel valves
as actuator, magnetic pickup unit as censor, and plant as fuel. The input and the
output of this control system is control how much speed that the engine needs.
So, from explanation above, we know that electronical governore is more
flexible and modern than mechanical governor. Generally, electronic systems
are not as reliable as mechanical systems. But it is possible to build
reliable control systems with more complex operations, accuracy, precision
and reliability. It can deliver fast, no-droop response to load changes and
isochronous speed control for gensets. They are up to 200 times faster than
mechanical governors. This means that there is no droop on gen-sets, so
power stays constant under variable loads on pumps and other engine
Trixie Marsya Rofifah
A deep hole is defined by its depth-to-diameter ratio (D:d), and typically holes
greater than 10:1 are considered deep holes. Deep hole drilling has a range of
applications across several industries, with its origins tracing back to the need
for straighter, more accurate gun barrels, and expanding as other industries
integrated deep hole drilling processes to improve their own applications. In
maritime field especially offshore, deep hole drilling system can be used in
deepwater drilling. Deepwater drilling, or Deep well drilling,is the process of
creating holes by drilling rig for oil mining in deep sea. There are approximately
3400 deepwater wells in the Gulf of Mexico with depths greater than 150
Figure 1
Figure 2
Another deep hole drilling system application in maritime field is shipbuilding.
In the manufacture of ships rotor shafts in particular but also in the case of
numerous components for pumps and powertrains, the field of shipbuilding
involves challenging deep hole drilling tasks that can be done with great
precision, reliably, and efficiently with deep hole drilling machines. But, this
paper will talk about deep hole drilling system application in offshore drilling.
How does deep hole drilling works in deep water? As the drill pipes are
connected, the conductor pipe and guide are run down to the sea floor. After
the conductor pipe penetrates the sea floor the drill pipe is released and pulled
back to the vessel. A large drill bit connected to the bottom of the drill pipe is
run down to the sea floor. The drill bit is lead down to the bottom of the hole
through the conductor pipe. The drill bit rotates and drills the sediment and
rock below the sea bed. Sea water is sprayed from nuzzles on the drill bit to
raise the cuttings to the sea floor.
After drilling several hundred meters the drill bit is pulled back to the vessel. A
casing pipe about 50cm in diameter is set into the drill hole to keep it from
collapsing. The casing pipe is run down through the conductor pipe and is
inserted into the hole using the drill pipe.
Figure 3
Figure 4
The main components of offshore deep hole drilling are:
 Crown block: sheaves (pulleys) over which the wire ropes attached to
the traveling block pass.
 Travelling block: used to support the weight of the drill string and to
hoist drill pipe into and out of the hole.
 Monkey board: small platform from which a monkey (derrick man) can
manoeuvre pipe stands into and out of the finger board.
 Finger board: provides a location for the drill pipe stands.
 Draw-works: it is a large hydraulically or electrically driven winch which
provides motive power to operate the travelling block and the rotary
 Rotary table: it imparts rotary motion to the drill string and permits the
passage of the drill string through bushings and also rotates the Kelly,
which is a hollow square pipe that fits into the top section of a drill pipe
and provides it with both rotational motion and drilling mud.
 Mousehole: a pipe into the drill floor in which a new section of drill pipe
is inserted before connecting it to the Kelly and including it in the drill
 Rathole: a pipe into the drill floor for the Kelly to go through while
making a trip.
 Pipe rack: area of deck in front of drilling derrick to store drill pipe and
 “V” door: V shaped opening in the windwall between the pipe rack and
the drill floor.
 Cat line: small winch used to transport drill pipe and casing from pipe
rack to drillfloor.
 Drill pipe: it is supplied in 30 ft (9m) lengths of either 3.5 or 5 inch
diameter with pin and box couplings at each end to permit assembly and
disassembly of the drill pipe.
 swivel - large handle that holds the weight of the drill string; allows the
string to rotate and makes a pressure-tight seal on the hole
 kelly - four- or six-sided pipe that transfers rotary motion to the
turntable and drill string
 turntable or rotary table - drives the rotating motion using power from
electric motors
 drill bit(s) - end of the drill that actually cuts up the rock; comes in many
shapes and materials (tungsten carbide steel, diamond) that are
specialized for various drilling tasks and rock formations
For the component of control system, offshore deep hole drilling has hole
depth sensor for sensors for tracking how depth of the well we drill, draw
works as the controller, drill bit as a plant, and swivel as the actuator. The
input/output is amount of the depth of the hole.
In the years that followed, petroleum companies moved even farther into the
ocean. Today's oil rigs are truly gigantic structures. Some are basically floating
cities, employing and housing hundreds of people. Other massive production
facilities sit atop undersea towers that descend as far as 4,000 feet (1,219
meters) into the depths -- taller than the world's most ambitious skyscrapers.
In an effort to sustain their fossil fuel dependency, humans have built some of
the largest floating structures on Earth. We can conclude that deep hole
drilling control system is very useful and important for maritime fields
especially in offshore drilling system.
Leheta, HW. Offshore Drilling. Egypt: University of Alexandria