lect 1 - overview process plant design (contd.)

8/3/2019 Lect 1 - Overview Process Plant Design (Contd.)

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Lecture 3. Plant Location and Layout

The selection of plant site is very important to ensure that it has all the support requiredto make the venture a feasible and profitable. There are many factors that must beconsidered when selecting a suitable site. The principal factors to consider are:

1. Location, with respect to the marketing area.

2. Raw material supply.3. Transport facilities.

4. Availability of labour.

5. Availability of utilities: water, fuel, power.

6. Availability of suitable land.

7. Environmental impact, and effluent disposal.

8. Local community considerations.

9. Climate.

10. Political and strategic considerations.

Selection of Site/Plant Location


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1. Location, with respect to the marketing area

The selection of location with respect to the above criteria depends on thecost of production versus the cost of transportation.

Most chemical/petrochemical process plant has significantly higherproduction cost compared to the cost for bulk transportation if thedistance is within certain range. Therefore, most of the time the locationselected is near to the transportation hub particularly sea port. This will

enable the delivery of the finished products to customer as quickly and ascheaply possible.

However, there are products that are produced in bulk quantities; such ascement, mineral acids, and fertilisers, where the cost of the product per tonneis relatively low compared to the cost of transportation which forms a

significant fraction of the sales price. In such cases, the plant should belocated close to the primary market.

All the above consideration may not apply or less important for low volumeproduction, high-priced products; such as pharmaceuticals.


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2. Raw material supply.

The supply of raw materials is one of the most important factors especiallywhen large quantities are involved. It lead to savings in the storage facilitiesas well as transports.

Thus the availability and price of suitable raw materials will often determine thesite location.

eg . Proximity of steelworks to the major coalfields in the UK, major petrochemicalcomplexes around Kertih where supply of natural gas from offshore Terengganu.

Plants producing bulk chemicals are best located close to the source of themajor raw material; where this is also close to the marketing area.


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3. Transport Facilities

The transport of materials and products to and from the plant will be an overridingconsideration in site selection. If practicable, a site should be selected that isclose to at least two major forms of transport i.e., road, rail, waterway (canalor river), or a sea port.

Land transport such as road transport is being increasingly used, and is suitablefor local distribution from a central warehouse. Rail transport will be cheaper for

the long-distance transport of bulk chemicals.

Air transport is convenient and efficient for the movement of personnel andessential equipment and supplies, and the proximity of the site to a major airportshould be considered.
http://www.google.com.my/imgres?imgurl=http://1.bp.blogspot.com/_zrOvBhtGoDw/R6NZxLC3B7I/AAAAAAAACnw/bp0C1Tza1E0/s400/transport.jpg&imgrefurl=http://rapsublog.blogspot.com/2008_02_01_archive.html&usg=__2-QPge33S7q9VSkeualJ8yeTJVg=&h=350&w=350&sz=68&hl=en&start=8&zoom=1&itbs=1&tbnid=4O1VU0O4NLXDsM:&tbnh=120&tbnw=120&prev=/search?q=transport+images&hl=en&sa=X&tbm=isch&prmd=ivns&ei=7k2lTYLDA4vPrQel2-ntCQhttp://www.google.com.my/imgres?imgurl=http://www.world-nuclear.org/images/info/ship.gif&imgrefurl=http://www.world-nuclear.org/info/inf20.html&usg=__BLFqnhXFnGS5Lb_8TuGq60WtezM=&h=375&w=504&sz=96&hl=en&start=7&zoom=1&itbs=1&tbnid=ei5YansXuO_gvM:&tbnh=97&tbnw=130&prev=/search?q=transport+images&hl=en&sa=X&tbm=isch&prmd=ivns&ei=7k2lTYLDA4vPrQel2-ntCQhttp://www.transportimages.com/gallery/v/air-travel


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4. Availability of labour.

Although the general trend is for increased automation, many processeswould still require a reasonably large labour force.

Labour will be needed for construction of the plant and its operation. Skilledconstruction workers will usually be brought in from outside the site area, butthere should be an adequate pool of unskilled labour available locally; and laboursuitable for training to operate the plant.

Skilled tradesmen will be needed for plant maintenance.

Local trade union customs and restrictive practices will have to be consideredwhen assessing the availability and suitability of the local labour for recruitmentand training.

In addition, the local pay rates, competing industries and turnover ratesneed to be also considered.
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5. Availability of utilities: water, fuel, power

Chemical processes invariably require large quantities of water for coolingand general process use, and the plant must be located near a source ofwater of suitable quality. Process water may be drawn from a river, fromwells, or purchased from a local authority. At some sites, the cooling waterrequired can be taken from a river or lake, or from the sea; at other locationscooling towers will be needed.

Electrical power will be needed at all sites. Electrochemical processes is anexample of a process which require large quantities of power.

A competitively priced fuel must be available on site for steam and powergeneration.
http://www.google.com.my/imgres?imgurl=http://www.mphusky.com/images/stories/utility%20plant%20photo2-web.jpg&imgrefurl=http://www.mphusky.com/cabl-bus/project-profiles?option=com_content&view=article&id=81&usg=__r5xtZhxmGtc46D4akenDHDzgpU8=&h=200&w=275&sz=67&hl=en&start=14&zoom=1&itbs=1&tbnid=2mqesEEQeXB9uM:&tbnh=83&tbnw=114&prev=/search?q=plant+utility&hl=en&sa=G&tbm=isch&ei=21ClTaaAH4LNrQei5-ngCQ


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6. Availability of suitable land.

Suitable land area with reasonable land rates (for hire or purchase) has to beidentified and selected.

May require approaching the local council office to explore the possibilities.

7. Environmental impact, and effluent disposal.

In a building chemical process plant, the environmental impact has to be assessed.

The assessment should be done to ascertain the impact of the surrounding as a result of

building the plant.

Normally, an environmental impact assessment study will be conducted prior toproject approval by the local council.
http://www.google.com.my/imgres?imgurl=http://www.cometoflorida.com/images/land.jpg&imgrefurl=http://www.cometoflorida.com/Main_Page/welcome__to_your_one.htm&usg=__uYA-yS2NA65mCPXGT7PzPnu6fHg=&h=1325&w=1766&sz=415&hl=en&start=11&zoom=1&itbs=1&tbnid=fva4-H5ukQIoYM:&tbnh=113&tbnw=150&prev=/search?q=land+images&hl=en&tbm=isch&ei=y1GlTeO7KcrtrQez-MTaCQ


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8. Local community considerations.

10 Political and strategic considerations.Stable country and political situation where there are not much possible public

disturbance

Financial incentives provided by the government and the tax policy

Financial facilities provided by the local businesses.

The local community in terms of facilities and support that could be provided.

9. Climate.

Climate can have an important bearing on the economic operation of the process.

Either a hot or cold severe climate, the cost of protective buildings, facilities forpersonnel and utilities must be considered especially when performing the economics.
http://www.google.com.my/imgres?imgurl=http://images.fastcompany.com/upload/climate-change.jpg&imgrefurl=http://www.fastcompany.com/1678172/even-a-completely-melted-polar-ice-cap-wouldnt-convince-deniers-of-climate-change-says-poll&usg=__uu0FGDDm8tA-bkNFFBS3h00faJs=&h=272&w=500&sz=81&hl=en&start=54&zoom=1&itbs=1&tbnid=RGK5xndV6NNjIM:&tbnh=71&tbnw=130&prev=/search?q=climate+images&start=36&hl=en&sa=N&ndsp=18&tbm=isch&ei=k1qlTeTmFsHMrQeR24jsCQhttp://www.google.com.my/imgres?imgurl=http://www.joanneum.at/climate/Pictures/Gletscher_small.jpg&imgrefurl=http://www.joanneum.at/climate/&usg=__XWdGDon0SMRkF_PASbASTeSvNdI=&h=332&w=450&sz=85&hl=en&start=28&zoom=1&itbs=1&tbnid=Hb8Sd66jv3MfGM:&tbnh=94&tbnw=127&prev=/search?q=climate+images&start=18&hl=en&sa=N&ndsp=18&tbm=isch&ei=clqlTY2cNs7NrQeJr6DgCQhttp://www.google.com.my/imgres?imgurl=http://www.cosmosmagazine.com/files/imagecache/news/files/20070419_climate.jpg&imgrefurl=http://www.cosmosmagazine.com/news/1229/climate-reporting-too-balanced-say-scientists&usg=__rTAUuORmfnvWgxJP0vFwfaxMwWY=&h=312&w=300&sz=83&hl=en&start=18&zoom=1&itbs=1&tbnid=pkpn6H3OX0ziIM:&tbnh=117&tbnw=113&prev=/search?q=climate+images&hl=en&tbm=isch&ei=RVqlTfD5D5CqrAfTn8DrCQhttp://www.google.com.my/imgres?imgurl=http://www.asiaexplorers.com/malaysia/kualalumpur/1utama/00.jpg&imgrefurl=http://www.asiaexplorers.com/malaysia/1_utama_shopping_centre.htm&usg=__ILeo4HZRVj-JcR8X0B8vWP152GA=&h=533&w=800&sz=153&hl=en&start=1&zoom=1&itbs=1&tbnid=Ce_crcXye4hqOM:&tbnh=95&tbnw=143&prev=/search?q=shopping+centres+images&hl=en&sa=G&tbm=isch&ei=_lilTdOFJcatrAfs_bjdCQhttp://www.google.com.my/imgres?imgurl=http://www.topnews.in/files/Lilavati-Hospital.jpg&imgrefurl=http://www.topnews.in/lilavati-set-another-300-bed-hospital-mumbai-243545&usg=__iXwqEioSSK-0kpwNW5zsdnT0Cc4=&h=229&w=350&sz=93&hl=en&start=31&zoom=1&itbs=1&tbnid=q1OgBWdayCelKM:&tbnh=79&tbnw=120&prev=/search?q=hospital+images&start=18&hl=en&sa=N&ndsp=18&tbm=isch&ei=uVilTdXpBseqrAeCweXmCQ


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Site/Plant LayoutAs with so many aspects of design, the layout of a process plant is not an exact science butrather an art, as it embraces a high degree of experience coupled with the need to anticipate

the human elements in both operation and maintenance. It is an important factor in that acarefully planned, functional arrangement of equipment, buildings and pipeworks is the key toeconomical construction and efficient operation.

Some of the principles to consider;

The process units and ancillary buildings should be laid out to give the most economical flow ofmaterials and personnel around the site.

Hazardous processes must be located at a safe distance from other buildings. Considerationmust also be given to the future expansion of the site.

The ancillary buildings and services required on a site, in addition to the main processing units(buildings), will include;

Storages for raw materials and products, tank farms and warehouses.

Maintenance workshops.

Stores, for maintenance and operating supplies.

Laboratories for process control.


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The ancillary buildings and services required on a site, in addition to the main processing units(buildings), will include (cont);

Fire stations and other emergency services.

Utilities: steam boilers,compressed air, power generation, refrigeration, transformerstations.

Effluent disposal plant.

Offices for general administration.

Canteens and other amenity buildings, such as medical centres.

Car parks.

There are two general methods which plant equipment could be positioned ;

i. Group Pattern vessels, exchangers, columns, pumps etc., are grouped together in separateareas for ease of operation and maintenance

ii. Flowline Pattern - equipment is laid out as arranged on the process flowsheet.

In larger plants, the first method is always used due to large numbers of similar units beingemployed. However, in practise a compromise between the two methods is normally used.


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An example of a site/plant layout


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The following guidelines may be employed in designing the site/plant layout ;

i. Minimum Labour Demands

When labour cost is high, automation could result in significant reduction in labour demands.Therefore, a central control room is required. Nevertheless, some labour outside the control roomis still required to perform certain manual operation but is kept to a low number.

For batch operation and start up/shut down operation of continuous plants where labour demandsare high, considerable savings could be made by arranging the units in an integrated manner asmuch as possible. This will minimise movements required over all the unit and thus could reducethe labour required. This will also help in the case of maintenance provided proper spacing isallocated for the all the units.

ii. Elevation of Equipment

Elevation of equipments is expensive and should only be kept to the absolutely necessary onesto ensure efficient operation eg. units employing gravity flow. There are cases where heavy andbulky items are elevated such as reactor but to arrange its elevation with the rest of the process

according to the process flow will enable advantage to be taken on using the gravity as the flowforce this eliminating pumps/compressors/conveyor belt thus cheaper on maintenance.

In general, heavy and bulky unit should be placed on the ground with proper support even at theexpense of using pressure to force the flow unnaturally eg. pressure in distillation unit pushes thevapour flow down to almost ground level where condenser is located.


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iii. Operating Convenience

Equipments requiring frequent attention should be grouped together to facilitate operation andmaintenance. However, the safety clearance between the units have to be observed to ensure

safest possible arrangement and the most hazard prone equipment is placed at the location mostconvenient for it to be removed.

A rectangular setup with a central over head pipe rack permits equipments to be installed alongboth sides of the pipe way with ease of access.

iv. Lay out of Specific Plant Equipments

It is convenient to locate pumps in line along each side of an access way with the motors alignedoutwards for easy access maintenance.

Equipments requiring large cranes for services should be located at the perimeter of therectangular set up, adjacent to a main roadway.

Compressors (expensive items) should be installed to allow for rapid dismantling and reassemblythus avoiding from the needs to have a stand by unit. Use compressors with bottom suction anddischarge connections and supporting it on a platform above ground level (approx 2.5 m or so)

v. Layout of Process Units

Large individual process units should be separated for efficient operation and maintenance and toavoid possible spread of fire and explosion.

A master plan should be made for grouping these equipments together and for future expansion.


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Other useful factors to consider;

The cost of construction can be minimised by adopting a layout that gives the shortest run

of connecting pipe between equipment, and the least amount of structural steel work.However, this will not necessarily be the best arrangement for operation and maintenance.

Valves, sample points, and instruments should be located at convenient positions andheights.

Heat exchangers need to be sited so that the tube bundles can be easily withdrawn forcleaning and tube replacement.

Vessels that require frequent replacement of catalyst or packing should be located on theoutside of buildings.

Equipment that requires dismantling for maintenance, such as compressors and largepumps, should be placed under cover.

Blast walls may be needed to isolate potentially hazardous equipment, and confine theeffects of an explosion.

Equipment should be located so that it can be conveniently tied in with any future

expansion of the process.

Space should be left on pipe alleys for future needs, and service pipes over-sized to allowfor future requirements.


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Other useful factors to consider (cont.) Services.;

Buildings of an ancilliary nature such as offices, workshops, canteen and power supply

should be located so as to afford maximum convenience with minimum interference withoperation of the plant.

Relief devices that can vent inflammable and noxious fumes in an emergency should belocated down wind of the administrative facility.

Storage areas should be positioned for ease of access from public roads and railways andremote from hazardous areas.

Facilities for generation and distribution of services (power supply, steam & water supply)should be located in a completely safe area.

For road used by all types of vehicles at all times, they should be surfaced and main two-way road should be at least 20ft (6.1 m) width with 30 ft (9.3 m) minimum centre line radiusto permit the turning of 3-4 axle vehicles.

Other useful factors to consider (cont.) Piping;

Overhead pipe network / yard piping which carries process materials and main utilities arenormally long and should be sited at or below ground level using racks. In most cases, thepower supply and instruments line are carried on the same structure.

Large pipes carrying process materials through the main process equipments should bemade as shortest possible but meeting all the clearance required. This could be achievedby grouping the common equipments together.


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Conclusions

We have gone through a number of main factors governing ;

the selection of site location which could have significant impact on the construction andoperation of the process plant.

the design of site layout which takes into account of operation and maintenancerequirement

Above all, there is no clear / systematic guidelines or procedures for designing site layout otherthan leveraging on some common sense rules thus making it more of an art rather thanscientific approach.


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Lecture 4. Plant Utility System

Many processes operate with a common utility system generated and located centrally.

BOILER

FEEDWATERTREATMENT &

DE-AERATOR

HP

MP

LP

Condensate ReturnBoiler Blowdown

Fuel

VHP

POWER

Emission

SteamMain

stoProcess

BOILER /USING FUEL ORGAS TURBINE EXHAUST

POWER

BACKPRESSURETURBINE

LET DOWN VALVE

LET DOWN VALVE

POWER

CONDENSINGTURBINE

CW

BACKPRESSURE

TURBINE

POWER

BACKPRESSURE

TURBINE


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The centralised utility system supplies steam, power and cooling water to the processes. It can alsosupply compressed air and refrigeration.

Condensate Return

Steam Supply

Condensate Return

Steam Supply

Condensate Return

Steam Supply

PROCESS 1

PROCESS 2

PROCESS 3

Cooling water cycle

CENTRALISEDUTILITY SYSTEM

POWER


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Steam is extensively used in most chemical/petrochemical plants for ;

indirect heating in steam heaters

Steam tracing for pipes and storage tanks

Direct heating through live steam injection

Vacuum creation through steam ejectors

Mass and heat exchange by live steam injection in distillation

Reduction of partial pressure in gas phase reactors

Combustion processes to atomise fuel oil Injection into combustion process to lower NO2 emissions

Power generation in steam turbine

This is due to a number of useful features which includes;

Energy can be generated at one point and distributed

A convenient way of transferring energy around

Has a high heat content as well as wide range of operating temperature

Non toxic and losses could be easily replaced

Does not require expensive materials of construction


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The main components or equipments in the central utility system normally comprise of;

1. Boiler feedwater treatment

Deaerator

LP steam

Vent

Filter

Ion Exchange

To boiler

Chemical Treatment

To treat water for removing suspended solids,dissolved solids, dissolved salts and dissolved gases.

To remove particularlycalcium and magnesium

which could causefouling in heat exchanger

To remove all inorganicsalts by using strong acidcation and base anionresin.

To remove dissolved gases principally O2 andCO2 which could cause corrosion.

To further remove the remaining

metal ions and dissolved gases left
http://en.wikipedia.org/wiki/File:Deaerator.png


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2. Steam Boilers

A fire-tube boiler is a type of boiler in which hot gases from a fire pass through one or more tubes runningthrough a sealed container of water. The heat of the gases is transferred through the walls of the tubes bythermal conduction, heating the water and ultimately creating steam.

Fire tube boiler.
http://en.wikipedia.org/wiki/File:Flammrohrrauchrohkessel.jpghttp://upload.wikimedia.org/wikipedia/commons/0/09/Locomotive_fire_tube_boiler_schematic.png


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Water tube boiler.

A water tube boiler is a type of boiler in which water circulates in tubes heated externally by the fire. They are

used for high-pressure boilers. Fuel is burned inside the furnace, creating hot gas which heats water in thesteam-generating tubes. In smaller boilers, additional generating tubes are separate in the furnace, while largerutility boilers rely on the water-filled tubes that make up the walls of the furnace to generate steam. The heatedwater then rises into the steam drum. Here, saturated steam is drawn off the top of the drum. In some services,the steam will reenter the furnace through a super heater to become superheated.
http://en.wikipedia.org/wiki/File:Brotans_boiler.jpghttp://upload.wikimedia.org/wikipedia/commons/0/0d/Water_tube_boiler_schematic.png


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3. Steam Turbines

A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and convertsit into rotary motion. It has almost completely replaced the reciprocating piston steam engine primarily

because of its greater thermal efficiency and higher power-to-weight ratio. Because the turbine generatesrotary motion, it is particularly suited to be used to drive an electrical generator about 80% of all electricitygeneration in the world is by use of steam turbines. The steam turbine is a form of heat engine that derivesmuch of its improvement in thermodynamic efficiency through the use of multiple stages in the expansion ofthe steam, which results in a closer approach to the ideal reversible process.

HP LP
http://en.wikipedia.org/wiki/File:Turbines_impulse_v_reaction.pnghttp://en.wikipedia.org/wiki/File:Dampfturbine_Montage01.jpghttp://en.wikipedia.org/wiki/File:Turbine_generator_systems1.png


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4. Gas Turbines

A gas turbine, also called a combustion turbine, is a rotary engine that extracts energy from a flow ofcombustion gas. It has an upstream compressor coupled to a downstream turbine, and a combustion chamber

in-between. Energy is added to the gas stream in the combustor, where fuel is mixed with air and ignited. Inthe high pressure environment of the combustor, combustion of the fuel increases the temperature. Theproducts of the combustion are forced into the turbine section. There, the high velocity and volume of the gasflow is directed through a nozzle over the turbine's blades, spinning the turbine which powers the compressorand, for some turbines, drives their mechanical output. The energy given up to the turbine comes from thereduction in the temperature and pressure of the exhaust gas.

GE H series power generation gas turbine: incombined cycle configuration, this 480-megawattunit has a rated thermal efficiency of 60%.
http://en.wikipedia.org/wiki/Combined_cyclehttp://en.wikipedia.org/wiki/Megawatthttp://en.wikipedia.org/wiki/Thermodynamic_efficiencyhttp://en.wikipedia.org/wiki/Thermodynamic_efficiencyhttp://en.wikipedia.org/wiki/Megawatthttp://en.wikipedia.org/wiki/Combined_cyclehttp://en.wikipedia.org/wiki/File:GE_H_series_Gas_Turbine.jpghttp://en.wikipedia.org/wiki/File:Jet_engine.svg


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4. Steam System Configuration

The steam system configuration enables the use of steam to be systematically and efficientlyexploited. The general policy adopted for steam usage is that for heating, lower pressure steam is

always used in preference to the high pressure steam. This would enable ;

Higher pressure steam to be used for power generation Higher latent heat content in the steam for the steam heater Lower capital cost heat transfer equipment due to lower pressure.

Steam system typically has 3 levels of steam pressure namely HP, MP and LP. For larger sites, ahigher level namely very high pressure (VHP) steam is generated for power production. The letdown steam from the turbine is then channeled into the steam system.

At times, the steam is expanded to lower pressure using expansion valve.

Flow control, or metering, of the expanded fluid is accomplished by use of atemperature sensing bulb filled with a similar gas as in the system that causes thevalve to open against the spring pressure in the valve body as the temperature onthe bulb increases.
http://en.wikipedia.org/wiki/File:PHT.jpg


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Also, every steam heaters used for heating process stream will be equipped with steam traps.

A steam trap is a device used to discharge condensate and non condensable gases with a negligibleconsumption or loss of live steam. Most steam traps are nothing more than automatic valves. They open,close or modulate automatically. Others, like venturi traps, are based on turbulent 2-phase flows to obstructthe steam flow. The three important functions of steam traps are:

Discharge condensate as soon as it is formed. Have a negligible steam consumption. Have the capability of discharging air and other non-condensable gases.


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5. Cooling Water

Cooling water circulation is used for process cooling such as in condenser or cooler. The

cooling water used has to be treated where possible to minimise fouling and corrosion thusextending equipment life and maintaining efficient heat transfer.

Natural and forced-draft cooling towers are generally used to provide the cooling waterrequired on a site; unless water can be drawn from a convenient river or lake in sufficientquantity.

Sea water, or brackish water, can be used at coastal sites, but if used directly will necessitatethe use of more expensive materials of construction for heat exchangers.

Cooling tower constitutes the main component of the cooling water circulation system besidesthe pumps needed for the water circulation and the chemical treatment required.


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Cooling Tower

Industrial cooling towers can be used to remove heat from various sources such as machinery or heatedprocess material. The primary use of large, industrial cooling towers is to remove the heat absorbed in the

circulating cooling water systems used in power plants, petroleum refineries, petrochemical plants, naturalgas processing plants, food processing plants, semi-conductor plants, and for other industrial facilities suchas in condensers of distillation columns, for cooling liquid in crystallization, etc. A typical large refineryprocessing 40,000 metric tonnes of crude oil per day (300,000 barrels (48,000 m3) per day) circulatesabout 80,000 cubic metres of water per hour through its cooling tower system.

There are 3 main types of heat transfer mechanism employed:

Wet cooling towersor simply open circuit cooling towersoperate on the principle of evaporation. Theworking fluid and the evaporated fluid (usually H2O) are one and the same.

Dry Cooling Towersoperate by heat transfer through a surface that separates the working fluid fromambient air, such as in a tube to air heat exchanger, utilizing convective heat transfer.

Fluid coolersor Closed Circuit Cooling Towersare hybrids that pass the working fluid through a tubebundle, upon which clean water is sprayed and a fan-induced draft applied.

There are three types of cooling towers:

Natural draft, which utilizes buoyancy via a tall chimney. Warm, moist air naturallyrises due to the densitydifferential to the dry, cooler outside air.Mechanical draft, which uses power driven fan motors to force or draw air through the tower.

Induced draft: A mechanical draft tower with a fan at the discharge which pulls air through tower. Forced draft: A mechanical draft tower with a blower type fan at the intake. The fan forcesair into

the tower, creating high entering and low exiting air velocities.


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A forced draft cooling tower
http://en.wikipedia.org/wiki/File:Factory_assembled_crossflow.jpghttp://en.wikipedia.org/wiki/File:Counterflow_diagram.PNGhttp://upload.wikimedia.org/wikipedia/commons/d/d0/Crossflow_diagram.PNGhttp://en.wikipedia.org/wiki/File:Forced_draft_cooling_tower.jpg


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6. Refrigeration (Vapour Compression Cycle)

Vapor-compression refrigeration[1] is one of the many refrigeration cycles available for use. Oil refineries,petrochemical and chemical processing plants, and natural gas processing plants are among the manytypes of industrial plants that often utilize large vapor-compression refrigeration systems.
http://en.wikipedia.org/wiki/File:RefrigerationTS.pnghttp://en.wikipedia.org/wiki/File:Refrigeration.png


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Conclusions

We have gone through the main components and arrangement of a typical plant centralised

utility system which consists of ;

Boiler feed water treatment

Steam boiler

Steam Turbine

Gas Turbine

Steam System Configuration

Cooling water

Refrigeration (only for plant with sub ambient temperature operation)

Together, they form the main and important support for ensuring successful plant operation.

lect 1 - overview process plant design (contd.)

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