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ASME Thermodynamics Section Project
American Society of Mechanical Engineering, UET Lahore chapter
this year, like every year, organized a team for the
Thermodynamic Section and assigned a project, Design Analysis
and Fabricate of Water Tube Boiler. The team
comprises of 18 members working as a unit to put forth their
immense effort in reaching a new milestone. The
Water Tube Boiler that is being worked on is to be forwarded in
various project exhibitions to demonstrate the
caliper of ASME UET Lahore chapter.
Some Specifications and Details of the Boiler
What is a water tube boiler?
A water-tube boiler is a type of boiler in which water
circulates in tubes which are heated externally by the fire.
Water-tube boilers are used for high-pressure boilers. Fuel (coal)
is burned inside the furnace, creating hot gas which heats up water
in the steam-generating tubes. In smaller boilers, additional
generating tubes are separate in the furnace, while larger utility
boilers rely on the water-filled tubes that make up the walls of
the furnace to generate steam.
A water tube boiler is more geared towards the latter setting
than the former though, since water tube boilers can create large
amounts of steam and recycle water for use again and again if kept
in a closed system.
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In water tube boilers, water is circulated though the tubes and
hot flue gases flow outside the tubes, e.g. Bob cock & Wilcox,
Admiralty three drum, Y-160 and Foster wheeler D-type. The water
tube boiler is employed for high pressure, high temperature, high
capacity steam applications, e.g. providing steam for main
propulsion turbines of cargo pump turbines.
Parts of a water tube boiler
Furnace - Furnace is usually membrane walled and gas tight. Most
of the heat transfer occurs in the furnace in the form of direct
radiation.
Super Heater - Inverted 'U' is most widely used. There are other
types like vertical 'S' type drainable. Super heater is usually
embedded in the boiler bank. When superheat temperature is high,
part of the super heater section is directly place in the furnace
to increase direct radiation and reduce size.
Boiler Bank - Boiler bank connects both the drums. Natural
circulation occurs without the aid of any external down comers
Economizer - Economizer is used downstream of Boiler bank to
preheat the feed water absorbing heat from hot exhaust gases
Pipes- In a water tube boiler, water runs through pipes. The
pipes are heated by surrounding fire or hot gases, and the more the
water is heated, the higher it goes until it becomes steam. The
pipes then allow the steam to escape into the upper drum.
Upper Drum- The upper drum is where the steam goes once it's
travelled the length of the pipes. The steam collects in the upper
drum, away from the heated pipe, and begins to condense back into
water. As the steam once more becomes liquid it drips down from the
upper drum and is collected in a lower drum, or the mud drum.
Lower Drum- The lower drum is set at the bottom of the water
tube boiler beneath the upper drum. The condensed steam collects
here and from the mud drum it goes back into the pipes. The more
pressure from built-up water, the more water that will be turned
back into steam and passed through the pipes yet again.
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Re-heater- The function of Re-heater is to reheat the steam
coming out from high pressure turbine. The Re-heater is composed of
two sections.
Burners- As evident from the name, these are used for burning
pulverized coal or oil.
Working Principle of a Water Tube Boiler
In the water-tube boiler, water flowed through tubes heated
externally by combustion gases, and steam was collected above in a
drum. Water tube boilers are very huge and their water holding
capacity is enormous. The water-tube boiler became the standard for
all large boilers as they allowed for higher pressures than earlier
boilers, higher than 30 b. Example, Babcock & Wilcox boiler
manufactured at Thermax Boilers Limited. It is a horizontal,
externally fired, stationary, high pressure, and water tube boiler
with a super heater
The coal is fed from hopper on to the grate where it is burnt.
The flue gases are deflected by the fire brick baffles so that they
pass across the left side of the tubes in a beneficial path
transferring heat to water in the tubes and to the steam in the
super heater and finally they escape into the atmosphere through
the chimney. The drought is regulated by a damper placed at the
back chamber.
The position of water tubes near the furnace is heated to a
higher temper than the rest. Owing to higher temperature, the
density of water decreases and hence the water rises through the
uptake header and short tube to the drum. The water at the back
end, which is at a lesser temperature, now travels down through the
long tube and the downcomer header. Thus, a continuous circulation
of water called as natural circulations established between the
water tubes and the drum. The steam
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produced gets collected above the water in the drum. Here,
saturated steam is drawn off the top of the drum. Since water
droplets can severely damage turbine blades, dry steam from the
steam-drum are again heated to generate superheated steam at 730F
(390C) or higher in order to ensure that there is no water
entrained in the steam. Cool water at the bottom of the steam drum
returns to the feed-water drum via large-bore 'downcomer
tubes', where it helps pre-heat the feed-water supply. To
increase the economy of the boiler, the exhaust gases are also used
to pre-heat the air blown into the furnace and warm the feed water
supply. Such water
tube boiler in thermal station is also called steam generating
unit.
Visit to The Industrial Enterprises, TIE
The ASME, Student body of UET Lahore chapter, Thermodynamic
Section organized an educational and field trip to The Industrial
Enterprises, TIE for all ASME members to aid them in the learning
of the working of Boiler and its manufacturing process. The
feedback from all the Thermodynamic Section members, the executive
body members and the faculty of TIE was appreciable. A delegation
was sent from UET Lahore to TIE prior to the visit to asking for
permission to visit them during their working hours so that
students could visually see and learn the various processes carried
out in the industry and workshops.
A van was arranged to take the members from UET to TIE and bring
them back to UET. The visit timings were from 10 am to 1 pm. After
we reached there, all members were first given a brief introduction
of TIE by a presentation in a hall, by TIE employees followed by a
cold drink break. A short question- answering session was also
conducted and all the queries of members were appropriately
answered by the TIE faculty. Later on we were allowed to explore
the industry on foot and observe all the processes being carried
out that could be relevant and useful for our boiler manufacturing.
Some of the relevant processes included welding, casting and
operations of a lathe machine.
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Thus a successful and informative field trip came to an end with
executive members briefing the section members of the manufacturing
processes with appropriate sequence to be used for boiler
construction. A technical discussion session was carried out
eventually to clarify any further queries regarding the
manufacturing.
As a result of the field trip new dates, deadlines and revised
tasks were then planned to finalize the fabrication process.
The Industrial Enterprises, TIE
The industrial enterprises mostly referred as TIE is a highly
specialized company. They manufacture
high and low pressure boilers plants which utilize the energy in
all types of biofuels, coal and other energy resources.
In operation since 1983 they have developed enhance and
innovative turn-key solutions for the benefit of their
customers, which so far have resulted in a long list of highly
satisfied clientele nationwide. The industrial enterprises
has knowledge based on many years of experience and their
ability to always think in alternative and different ways
has enabled them to apply the latest the latest know-how to
create even better more effective energy solutions.
The industrial enterprises always
supply customized turn-key solutions designed to
meet the customer needs, and we thoroughly
analyze every single project to develop and deliver
the best possible to our customer. TIE produce
tailored boiler plants that fulfill specific
requirements, and they see opportunities and
solution where other sees problems.TIE is always
one step ahead often supplying its customers the possible energy
plants better than they expected and they supply a
boiler that requires low investment and gives them in turn a
longer lifetime of the product and requires a minimum
of maintenance. So, choosing a boiler from TIE is more
beneficial for the customers. TIE,s boiler plants comply with
NEQS and other international environmental standards.
Being a family own company and today ran by a second generation
we have earned a lot of experience and
have good cooperation with the clients. In case of a breakdown
for 24 hours we are rather at repairing and
rectification of customers boilers combustion equipment and any
other auxiliary equipment. Taking the lead puts
you under an obligation, but it always more challenging than
following other footsteps.
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Multi-fuel utilization
The boilers can be operated with a broad range of fuels. Beside
traditional fuels such as coal, gas, oil and bio-mass(bagasse,
mustard, stalk, cotton stalk, rice husk, coffee grounds, de-oil
brans and wood chips) there
are special designs as well where industrial waste, municipal
waste and hazardous waste can be utilized.
Customer focus
Typical Industries we supply TIE boilers:
Sugar Mills.
Paper Mills.
Textile processing units.
Steel mills.
Food and beverage industry.
Industrial / commercial power plants.
Vision
Our vision is to create a better society through environment
friendly innovative energy solutions.
Mission
Our mission is to create value for our customers by continuous
developing and adapting innovative
technologies and resources to fulfill market Energy demands.
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Products
Boilers
TIE supply boiler plants for the production of steam, heat and
electricity according to the customers
needs and meeting their optimum requirements. Our business plan
is to manufacture, erect and commission the
boiler plants.
They use the experience they have gained over decades to supply
technically well-proven and high
quality boilers from our own production. TIE guarantees economic
and environmental friendly operating
parameters.
TIE designs and manufactures the Boilers as water tube type for
steam and heat generation purposes.
Steam rating 6 T/h to 200 T/h
Steam pressure 10 bar(g) to 105 bar(g)
Steam Temperature Up to 535 `c
Design Flexibility
For every application we choose a particular design, which
includes various fuels and combustion systems.
This particular design usually takes into account:
o The compatibility to the fuel requirements. o The optimization
for the space conditions on the site.
Capacity Spectrum
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Advaages of TIE Boilers
o Rapid cold start-up.
o High steam purity.
o Good fit to space requirements.
o Fast response to negative and positive load variations.
o Best Thermodynamic design and workmanship.
o High rate of combustion and low emissions.
o Increased effective heating surface.
o Technically highest possible efficiency.
o Higher strength and clearly improved welding quality.
o Manholes, heads and hand holes
where necessary and a large space
inside the boiler.
o High quality and time-tested
components for firing and control
systems.
o Modern manufacturing methods.
o Inspection and acceptance through
International Codes authorities.
Waste Heat Recovery Boilers
The supplies waste heat recovery systems for thermal processes
where hot gases are used to generate the hot water and steam for
process and power generation. The recovered waste heat increases
the
overall efficiency of the system. In any sense waste heat
boilers make sense from any ecological point of view.
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We design waste heat boilers as water tube boilers, with natural
circulation, for a wide range of
thermodynamic tasks. Our know-how in designing the waste heat
boilers is the basis in controlling the thermal,
chemical and mechanical loadings even under difficult process
conditions
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TIE supplies complete plants or custom-made waste heat systems
for CHP units with:
o Gas Engines.
o Gas Turbines.
o Diesel/HFO Engines.
o Induction Furnaces.
Depending on the operational parameters and waste gas quality,
waste heat boilers are designed as
water tube type. Supplementary firing equipment is often added o
increase the heat output and improve the
controllable operating range.
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Services Business
We offer a wide range of
products and services ranging
from the supply of spare parts to
the servicing of complete energy
plants. We can supply retrofit
equipment and spare parts,
perform repair works, upgrades
of entire plants or plant
equipment, as well as perform
plant optimization to achieve the
best possible operating
conditions. Revamping can
improve plant operation and
performance, increase
efficiency, and ensure compliance with environmental
standards.
We offer a wide range of products and services ranging from the
supply of spare parts to the servicing of
complete energy plants. We can supply retrofit equipment and
spare parts, perform repair works, upgrades of entire
plants or plant equipment, as well as perform plant optimization
to achieve the best possible operating conditions.
Revamping can improve plant operation and performance, increase
efficiency, and ensure compliance with
environmental standards.
Our service program includes:-
o Supply of plant components and equipment.
o Revamping and upgrading.
o Repair and Maintenance.
o Condition assessment and performance optimization.
o Spare parts.
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Plant Components and Equipment
o Biomass and coal combustion grates.
o Ash and clinker handling systems.
o Super-heaters.
o Economizers.
o Air Pre-heaters.
o Soot Blowers.
o Pressure vessels, towers and columns.
o Heat Exchangers.
Revamping & Upgrading
o Replacement and renovation of plant components.
o Performance of scheduled repair works and periodic plant
revisions.
o Immediate rectification of unforeseen breakdowns. o Planning
and completion of preventive inspections, maintenance and repairs.
o Long term maintenance program.
Condition assessment & performance optimization
o Assessment and analysis of plant condition and operation.
o Recommended measures for optimization.
o Budgets and schedules for optimization.
o Implementation of optimization measures.
o Adjustment and trimming of existing and new equipment.
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Spare parts
o Parts for plant equipment and auxiliaries in general. o Stock
holding of critical spare part for immediate delivery.
Conclusion
It was a very productive Industrial tour. All the students
enjoyed this and from learning point of
view it was too much informative for all juniors and seniors
members. The students of different departments also
got an opportunity to see each other. All appreciated the
management and expected more such tours to different
multinational industries all over the Pakistan.
Rizwan Ali Bsc. Mechanical Engineering Student
Assistant Manager Thermodynamics Section
ASME UET Lahore, Pakistan [email protected]
+92-300-4094863
mailto:[email protected]
