Harsh2155

Improve efficiency of condenser by passivation
S.B.POLYTECHNIC, SAVLI Page 2
1.2 Company product
1.2.1 Products Offered
1. Chilling Plant
2 Anodized chilling plant
3 Ammonia plant
4 Dairy plant
5 Pharmaceutical chilling plant
6 Marine Refrigeration
7 Air condition plant
8 Chiller Condenser
9 Cooling System Services & Maintenance
Table.1.1
1.2.2 Focused Products
1 Chilling Plant
2 Anodized chilling plant
3 Ammonia plant
4 Chemical chilling plant
Table.1.2

1.3 QUALITY CONTROL
1.3.1 ISO 9001:2008
Transpek ensures that all the products manufactured
and supplied are under the accreditation
of ISO
9001:2008 Quality Management Systems.
Accompanied with strong supporting functions,
Transpek ensures effective and accurate customer response on quality, corrective
and preventive actions.
Transpek’s continual quality improvements and corrective
application of overall quality management is a medium to
enhance the product, process and environmental safety and to reduce manufacturing costs.
1.3.2 ISO 14001:2004
Transpek is accredited with ISO 14001:2004 for environment management system.
Transpekapplies production processes that avoid endeavors effect on the environment by
employing responsible waste management and minimization, energy efficiency and
community relations.
These endeavors reflect upon Transpek’s efforts towards a sustainable growth
andenvironmental protection.
1.3.3 BS OHSAS 18001:2007
(Occupational Health & Safety Assessment Series)
Organizations are increasingly concerned with achieving and demonstrating Occupational
Health and Safety (OH&S) performance by designing and implementing sound OH&S
policies and objectives. These are to be done in the context of increasingly stringent
legislations and also the increased concern expressed by various stakeholders about OH&S
issues.
Transpek is accredated with OHSAS 18001 system for the strengthening Health and Safety
standards. Through this system, Hazard Identification and Risk Assessment of all the
activities are carried out. Awareness is continuous being created at all levels through training
including contractors and other interested parties.
We are planning to integrate all these systems during the year.

1.4 RESEARCH AND DEVELOPMENT
The strength of Transpek's R & D is evident from the fact that the manufacturing
technology for all of its existing products was developed in-house
Our R & D facility is recognized by CSIR/DST (Govt. of India) as an approved
Research Center. All the products in the Transpek’s range are developed in-house
using innovative, appropriate and environment friendly technologies.
The R & D Infrastructure is made up of modern testing facilities like HPLC, GC,
FTIR Spectrophotometer, UV Spectrophotometer, Thermal Gravimetric Analyzer etc & a
24 hour accessible Technical Library.
Transpek has an excellent track record in manufacturing and development. The capability
to produce gram to multi-kilogram quantities of compounds is proven. Transpek works in
close partnership with clients, under strict confidentiality to bring products to the market.

CHAPTOR NO.2 REFRIGERANT CIRCUIT
 The physical terms for the refrigeration process have been dealt with previously, even
though for practical reasons water is not used as a refrigerant.A simple refrigerant
circuit is built up as shown in the sketch below. In what follows, the individual
components are described to clarify a final overall picture
EVAPORATOR
 A refrigerant in liquid form will absorb heat when it evaporates and it is this
conditional change that produces cooling in a refrigerating process. If a refrigerant at
the same temperature as ambient is allowed to expand through a hose with an outlet to
atmospheric pressure, heat will be taken up from the surrounding air and evaporation
will occur at a temperature corresponding to atmospheric pressure. If in a certain
situation pressure on the outlet side (atmospheric pressure) is changed, a different
temperature will be obtained since this is analogous to the original temperature - it is
pressuredependent. The component where this occurs is the evaporator, whose job it
is to remove heat from the surrounding.
COMPRESSOR
 A simple refrigerant circuit is built up as shown in the sketch below. In what follows,
the individual components are described to clarify a final overall picture. A refrigerant
in liquid form will absorb heat when it evaporates and it is this conditional change
that produces cooling in a refrigerating process. If a refrigerant at the same
temperature as ambient is allowed to expand through a hose with an outlet to
atmospheric pressure, heat will be taken up from the surrounding air and evaporation
will occur at a temperature corresponding to atmospheric pressure. If in a certain
situation pressure on the outlet side (atmospheric pressure) is changed, a different
temperature will be obtained since this is analogous to the original temperature - it is
pressuredependent. The component where this occurs is the evaporator, whose job it
is to remove heat from the surroundings, i.e. to produce refrigeration. The
refrigeration process is, as implied, a closed circuit. The refrigerant is not allowed to
expand to free air. When the refrigerant coming from the evaporator is fed to a tank
the pressure in the tank will rise until it equals the pressure in the evaporator.

Therefore, refrigerant flow will cease and the temperature in both tank and evaporator
will gradually rise to ambient. To maintain a lower pressure, and, with it a lower
temperature it is necessary to remove vapour. This is done by the compressor, which
sucks vapour away from the evaporator. In simple terms, the compressor can be
compared to a pump that conveys vapour in the refrigeration circuit. In a closed
circuit a condition of equilibrium will always prevail. To illustrate this, if the
compressor sucks vapour away faster than it can be formed in the evaporator the
pressure will fall and with it the temperature in the evaporator. Conversely, if the load
on the evaporator rises and the refrigerant evaporates quicker, the pressure and with it
the temperature in the evaporator will rise.
COMPRESSOR METHOD OF OPERATION
 Refrigerant leaves the evaporator either as saturated or weak superheated vapour and
enters the compressor where it becomes compressed. Compression is carried out as in
a petrol engine, i.e. by the movement of a piston. The compressor requires energy and
carries out work. This work is transferred to the refrigerant vapour and is called the
compression input. Because of the compression input, vapour leaves the compressor
at a different pressure and the extra energy applied causes strong superheating of the
vapour. Compression input is dependent on plant pressure and temperature. More
work is of course 3.3 Compressor, method of operation required to compress 1 kg
vapour 10 bar than to compress the same amount 5 bar.

CONDENSER
 The refrigerant gives off heat in the condenser, and this heat is transferred to a
medium having a lower temperature. The amount of heat given off is the heat
absorbed by the refrigerant in the evaporator plus the heat created by compression
input. The heat transfer medium can be air or water, the only requirement being that
the temperature is lower than that which corresponds to the condensing pressure. The
process in the condenser can otherwise be compared with the process in the
evaporator except that it has the opposite “sign”, i.e. the conditional change is from
vapour to liquid.
EXPANSION PROCESS
 Liquid from the condenser runs to a collecting tank, the receiver. This can be likened
to the tank mentioned under section 3.1 on the evaporator. Pressure in the receiver is
much higher than the pressure in the evaporator because of the compression (pressure
increase) that has occurred in the compressor. To reduce pressure to the same level as
the evaporating pressure a device must be inserted to carry out this process, which is
called throttling, or expansion. Such a device is therefore known either as a throttling
device or an expansion device. As a rule a valve is used - a throttle or expansion
valve. Ahead of the expansion valve the liquid will be a little under boiling point. By
suddenly reducing pressure a conditional change will occur; the liquid begins to boil
and evaporate. This evaporation takes place in the evaporator and the circuit is thus
complete.

HIGH AND LOW PRESSURE SIDE OF REFRIGERATION
PLANT
 There are many different temperatures involved in the operation of a refrigeration
plant since there are such things as subcooled liquid, saturated liquid, saturated vapour
and superheated vapour. There are however, in principle, only two pressures;
evaporating pressure and condensing pressure. The plant then is divided into high
pressure and low pressure sides, as shown in the sketch.
MATERIALS COMPATIBILITY FOR AMMONIA
-NOT PERMITTED
-Copper and copper alloys such as brass are prohibited(but allowed for bearing materials)
-Zinc (in continuous contact with ammonia)
-Non –metalic materials that degrade upon exposure
-PERMITTED
-Carbon steel
-stainless steel
-Aluminum
-Other non-metallic materials such as PTFE are permitted (if they will not break down)

CHAPTOR NO.3
AMMONIA VAPOR COMPRESSION CYCLE IN MECHANICAL
REFRIGERATION
Mechanical refrigeration is a process for exchanging heat to effect a desired temperature in
an environment and/or an end product. The state-of-the-art in current mechanical
refrigeration technology involves the transfer of the refrigerant through its liquid and vapor
states by mechanical compression, condensation, and evaporation. This guideline for safety
relates specifically to the mechanical functions and the associated equipment incorporated in
the typical ammonia vapor-compression system.
FIG. VAPOR COMPRESSOR CYCLE
Figure : shows the schematic of an ammonia-water absorption refrigeration system.
Compared to water-lithium bromide systems, this system uses three additional components: a
rectification column,a dephlegmator and a subcooling heat exchanger(Heat Exchanger-I). As
mentioned before, the function of rectification column and dephlegmator is to reduce the
concentration of water vapour at the exit of the generator. Without these the vapour leaving
the generator may consist of five to ten percent of water. However, with rectification column
and dephlegmator the concentration of water is reduced to less than one percent. The
rectification column could be in the form of a packed bed or a spray column or a perforated

plate column in which the vapour and solution exchange heat and mass. It is designed to
provide a large residence timefor the fluids so that high heat and mass transfer rates could be
obtained. The subcooling heat exchanger, which is normally of counterflow type is used to
increase the refrigeration effect and to ensure liquid entry into the refrigerant expansion
valve.
As shown in the figure, low temperature and low pressure vapour (almost pure ammonia) at
state 14 leaves the evaporator, exchanges heat with the condensed liquid in Heat Exchanger-I
and enters the absorber at state 1. This refrigerant is absorbed by the weak solution (weak in
ammonia) coming from the solution expansion valve, state 8. The heat of absorption, Qais
rejected to an external heat sink. Next the strong solution that is now rich in ammonia leaves
the absorber at state 2 and is pumped by the solution pump to generator pressure, state 3. This
high pressure solution is then pre-heated in the solution heat exchanger (Heat Exchanger-II)
to state 4. The preheated solution at state 4 enters the generator and exchanges heat and mass
with the hot vapour flowing out of the generator in the rectification column. In the generator,
heat is supplied to the solution (Qg). As a result vapour of ammonia and water are generated
in the generator.As mentioned, this hot vapour with five to ten percent of water exchanges
heat and mass with the rich solution descending from the top. During this process, the
temperature of the vapour and its water content are reduced. Thisvapour at state 5 then enters
the dephlegmator, where most of the water vapour in the mixture is removed by cooling and
condensation. Since this process is exothermic, heat (Qd) is rejected to an external heat sink
in the dephlegmator. The resulting vapour at state 10, which is almost pure ammonia (mass
fraction greater than 99 percent) then enters the condenser and is condensed by rejecting heat
of condensation, Qcto an external heat sink. The condensed liquidat state 11 is subcooled
tostate 12 in the subcooling heat exchanger by rejecting heat to the low temperature, low
pressure vapour coming from the evaporator. The subcooled, high pressure liquid is then
throttled inthe refrigerant expansion valve to state 13. The low temperature, low pressure and
low quality refrigerant then enters the evaporator, extractsheat from the refrigerated space
(Qe) and leaves the evaporatorat state 14. From here it enters the subcooling heat exchanger
to complete the refrigerant cycle. Now, the condensed water in the dephlegmator at state 9
flows down into the rectifying column along with rich solution and exchanges heat and mass
with the vapour moving upwards. The hot solution that is now weak inrefrigerant at state 6
flows into the solution heat exchanger where it is cooled to state 7 by preheating the rich
solution.The weak, but high pressure solution at state 7 is then throttled in the solution
expansion valve to state 8, from where it enters the absorber to complete its cycle.
As far as various energy flows out of the system are concerned, heat is supplied to the system
at generator and evaporator, heat rejection takes place at absorber, condenser and
dephlegmator and a small amount of work is supplied to the solutio

AMMONIA REFRIGERATION TECHNOLOGY
-Single stage comnpression with evaporators configured as
-direct expansion
-flooded
-overfeed
-Multi-stage compression systems
-cascade systems

ACCUMULATOR
FIG : ACCUMULATOR
Nozzle
Description Connection
A Wet Return Stub
B Gas Outlet Stub
C Liquid Outlet Stub
E Float Column Stub
F Relief Coupling
G Oil Pot Drain Stub
H Oil Pot Vent Coupling
J Drain Coupling

HORIZONTAL ACCUMULATOR
Selection of a suction line accumulator should be made on the basis of the following three
capabilities. The accumulator should have an adequate liquid holding capacity, which can
vary with the system. Normally this should not be less than 50% of the system charge. If
possible this value should be checked based on actual tests.
A second consideration should be the ability of the accumulator to perform without adding
excessive pressure drop to the system. The recommended maximum tonnages shown in the
following tables are based on a pressure drop equivalent to 1/2° F. These ratings are those of
the accumulator, based on oil return through the accumulator, and will be modified by the
length of the suction line and compressor displacement. Finally an accumulator should have
the capability of returning liquid at the proper rate and under a range of load conditions.
Accumulators should have a Heat Element added on low temperature applications (0° F and
below) such as the S-9111 or S-9112 to help boil off liquid refrigerant and raise the oil
temperature to help facilitate oil flow.

The Parker “U” tube accumulator design is a result of extensive laboratory testing plus
detailed investigation of the various accumulators currently available. It takes into account all
of the requirements essential for heat pump applications, including safe holding volume
(relative to the system’s total charge), protected flow control for positive refrigerant and oil
return, and minimum pressure drop across the accumulator.
Parker offers standard accumulator models designed for application on heat pump and
refrigeration systems from 1/4 through 12 tons. Liquid refrigerant holding requirements of
suction accumulator may vary by application. Because of the diversity in heat pump systems,
accumulator capacity selection should be determined by actual testing. Consult Parker for
assistance if required.

CHAPTER.NO:4 PROBLEMIDENTIFICATION
4.1 FISHBONE DIAGRAM
Fig4.1–FishboneDiagram
A fishbone diagram, also called a cause and effect diagram or Ishikawa
diagram, is a visualization tool for categorizing the potential causes of a
problem in order to identify its root causes.
A fishbone diagram is useful in brainstorming sessions to focus conversation. After
the group has brainstormed all the possible causes for a problem, the facilitator
helps the group to rate the potential causes according to their level of importance
and diagram a hierarchy. The design of the diagram looks much like a skeleton of a
fish. Fishbone diagrams are typically worked right to left, with each large "bone"
of the fish branching out to include smaller bones containing more detail.

4.2PROBLEM ON SYSTEM
PROBLEMS FACEING IN PROCESS
 Tube of chiller and Condenser is not ok
FIG- OPEN CONDENSER

CHAPTER NO:-5 CONDENSER
In systems involving heat transfer, a condenser is a device or unit used to
condense a substance from its gaseous to its liquid state, by cooling it. In so
doing, the latent heat isgiven up by the substance and transferred to the
surrounding environment.
Condensers can be made according to numerous designs, and come in many
sizes ranging from rather small(hand-held) to very large (industrial-scale units
used in plant processes). For example,a refrigerator uses a condenser to get rid
of heat extracted from the interior of the unit to the outside air.
FIG-CONDENSER
Baffle Design: baffles are used in shell and tube heat exchangers to direct fluid across the
tube bundle. They run perpendicularly to the shell and hold the bundle, preventing the tubes
from sagging over a long length. They can also prevent the tubes from vibrating. The most
common type of baffle is the segmental baffle. The semicircular segmental baffles are
oriented at 180 degrees to the adjacent baffles forcing the fluid to flow upward and
downwards between the tube bundle. Baffle spacing is of large thermodynamic concern when
designing shell and tube heat exchangers. Baffles must be spaced with consideration for the
conversion of pressure drop and heat transfer. For thermo economic optimization it is
suggested that the baffles be spaced no closer than 20% of the shell’s inner diameter.

CONDENSER
As already mentioned, condenser is an important component of any refrigeration system. In a
typical refrigerant condenser, the refrigerant enters the condenser in a superheated state. It is
first de-superheated and then condensed by rejecting heat to an external medium. The
refrigerant may leave the condenser as a saturated or a sub-cooled liquid, depending upon the
temperature of the external medium and design of the condenser. Figure 22.1 shows the
variation of refrigeration cycle on T-s diagram. In the figure, the heat rejection process is
represented by 2-3’-3-4. The temperature profile of the external fluid, which is assumed to
undergo only sensible heat transfer, is shown by dashed line. It can be seen that process 2-3’
is a de-superheating process, during which the refrigerant is cooled sensibly from a
temperature T2 to the saturation temperature corresponding condensing pressure, T3’.
Process 3’-3 is the condensation process, during which the temperature of the refrigerant
remains constant as it undergoes a phase change process.
In actual refrigeration systems with a finite pressure drop in the condenser or in a system
using a zeotropic refrigerant mixture, the temperature of the refrigerant changes during the
condensation process also. However, at present for simplicity, it is assumed that the
refrigerant used is a pure refrigerant (or an azeotropic mixture) and the condenser pressure
remains constant during the condensation process. Process 3-4 is a sensible, sub cooling
process, during which the refrigerant temperature drops from T3 to T4.

The change from liquid phase to vapor phase is called vaporization and the reverse phase
transfer is condensation. The change from liquid to vapor or vapor to liquid occurs at one
temperature (called saturation or equilibrium temperature) for a pure fluid compound at a
given pressure. The industrial practice of vaporization and condensation occurs at almost
constant pressure; therefore the phase change occurs isothermally. Condensation occurs by
two different physical mechanisms i.e. drop-wise condensation and film condensation .The
nature of the condensation depends upon whether the condensate (liquid formed from vapor)
wets or does not wet the solid surface. If the condensate wets the surface and flows on the
surface in the form of a film, it is called film condensation. When the condensate does not
wet the solid surface and the condensate is accumulated in the form of droplets, is drop-wise
condensation.
Heat transfer coefficient is about 4 to 8 times higher for drop wise condensation.
The condensate forms a liquid film on the bare-surface in case of film condensation. The
heat transfer coefficient is lower for film condensation due to the resistance of this liquid
film. Dropwise condensation occurs usually on new, clean and polished surfaces. The heat
exchanger used for condensation is called condenser. In industrial condensers, film
condensation normally occurs.

AMMONIA RECEIVER
FIG : AMMONIA RECEIVER
Horizontal high pressure receivers provide the main source of liquid refrigerant for a
refrigeration system. It also provides a place to store refrigerant as needed to minimize the
effect of system transients. In some system designs the high pressure receiver is also designed
to store the entire system charge. This allows the system to be pumped down for
maintenance.
PHOTO : RECEIVER

PLATE HEAT EXCHANGER (PHE)
FIG : PLATE HEAT EXCHANGER
The plate heat exchanger (PHE) is a specialized design well suited to transferring heat
between medium- and low-pressure fluids. Welded, semi-welded and brazed heat exchangers
are used for heat exchange between high-pressure fluids or where a more compact product is
required. In place of a pipe passing through a chamber, there are instead two alternating
chambers, usually thin in depth, separated at their largest surface by a corrugated metal plate.
The plates used in a plate and frame heat exchanger are obtained by one piece pressing of
metal plates. Stainless steel is a commonly used metal for the plates because of its ability to
withstand high temperatures, its strength, and its corrosion resistance.
The plates are often spaced by rubber sealing gaskets which are cemented into a section
around the edge of the plates. The plates are pressed to form troughs at right angles to the
direction of flow of the liquid which runs through the channels in the heat exchanger. These
troughs are arranged so that they interlink with the other plates which forms the channel with
gaps of 1.3–1.5 mm between the plates. The plates are compressed together in a rigid frame
to form an arrangement of parallel flow channels with alternating hot and cold fluids. The
plates produce an extremely large surface area, which allows for the fastest possible transfer.
Making each chamber thin ensures that the majority of the volume of the liquid contacts the
plate, again aiding exchange. The troughs also create and maintain a turbulent flow in the
liquid to maximize heat transfer in the exchanger. A high degree of turbulence can be
obtained at low flow rates and high heat transfer coefficient can then be achieved.

PHOTO : PLATE HEAT EXCHANGER
As compared to shell and tube heat exchangers, the temperature approach in a plate heat
exchangers may be as low as 1 °C whereas shell and tube heat exchangers require an
approach of 5 °C or more. For the same amount of heat exchanged, the size of the plate heat
exchanger is smaller, because of the large heat transfer area afforded by the plates (the large
area through which heat can travel). Increase and reduction of the heat transfer area is simple
in a plate heat-exchanger, through the addition or removal of plates from the stack.
The plates are commonly made of AISI 304/316 or titanium, but can also be made from other
pressable and exotic materials. The type of material depends on the treated media and their
temperatures. The plates form the plate pack, which is held firmly between the head and the
follower of the frame. The corrugated pattern on the plates ensures a turbulent flow in the
entire heat transmission area, and is designed to eliminate “dead zones”. The choice of plate
pattern depends on the type of media that is treated in the heat exchanger. We offer a large
variety of different plate patterns, from fishbone patterns in varying pressing depths and
angles, to Free Flow patterns that allow media containing particles and fibres to pass through
the heat exchanger unimpeded.

EXPANSTONE VALVE AND EAPORATOR
FIG : AUTOMATIC EXPANSTONE VALVE
The main purpose of the expansion valve is to ensure a sufficient pressure differential
between the high and low pressure sides of the plant. The simplest way of doing this is to use
a capillary tube inserted between the condenser and eva
PHOTO : EXPANSTONE VALVE

The capillary tube is, however, only used in small, simple appliances like refrigerators be
This Photo shows an evaporator fed by a thermostatic expansion valve. A small amount of
liquid is contained in a part of the bulb. The rest of the bulb, the capillary tube and the space
above the diaphragm in the valve housing is charged with saturated vapour at a pressure
corresponding to the temperature at the bulb. The space under the diaphragm is in connection
with the evaporator and the pressure is therefore equal to the evaporating pressure.
PHOTO : EVAPORATOR
cause it is not capable of regulating the amount of liquid that is injected into the evaporator.
A regulating valve must be used for this process, the most usual being the thermostatic
expansion valve, which consists of a valve housing, capillary tube and a bulb. The valve
housing is fitted in the liquid line and the bulb is fitted on the evaporator outlet.
If the evaporator receives too little refrigerant the vapour will be further superheated and the
temperature at the outlet pipe will rise. The bulb temperature will then also rise and with it
the vapour pressure in the bulb element since more of the charge will evaporate. Because of
the rise in pressure the diaphragm becomes forced down, the valve opens and more liquid is
supplied to the evaporator. Correspondingly, the valve will close more if the bulb temperature
becomes lower.

PHOTO : EVAPORATOR COIL
Depending on the application, various requirements are imposed on the evaporator.
Evaporators are therefore made in a series of different versions.
Evaporatorsfor natural air circulation are used less and less because of the relatively poor heat
transfer from the air to the cooling tubes. Earlier versions were fitted with plain tubes, but
now it is common to use ribbed tubes or finned elements.
Evaporator performance is increased significantly if forced air circulation is used. With an
increase of air velocity the heat transfer from air to tube is improved so that for a given cold
yield a smaller evaporator surface than for natural circulation can be used.
As the name implies, a chiller cools down liquid. The simplest method is to immerse a coil of
tube in an open tank. Closed systems are coming into use more and more. Here, tube coolers
made similar to shell and tube condensers are employed.

CHAPTER NO:-6
COOLING TOWER
PHOTO : COOLING TOWER
A cooling tower is a heat rejection device that rejects waste heat to the atmosphere through
the cooling of a water stream to a lower temperature. Cooling towers may either use
the evaporation of water to remove process heat and cool the working fluid to near the wet-
bulb air temperature or, in the case of closed circuit dry cooling towers, rely solely on air to
cool the working fluid to near the dry-bulb air temperature.
Common applications include cooling the circulating water used in oil refineries,
petrochemical and other chemical plants, thermal power
stations and HVAC systems for cooling buildings. The classification is based on the type of
air induction into the tower: the main types of cooling towers are natural draft and induced
draft cooling towers.
Cooling towers fall into two main sub-divisions: natural draft and mechanical draft. Natural
draft designs use very large concrete chimneys to introduce air through the media.
Mechanical draft cooling towers are much more widely used. These towers utilize large fans
to force air through circulated water. The water falls downward over fill surfaces which help
increase the contact time between the water and the air. This helps maximize heat transfer
between the two.
Heat is transferred from water drops to the surrounding air by the transfer of sensible and
latent heat.
What are cooling towers? Cooling towers are a special type of heat exchanger that allows
water and air to come in contact with each other to lower the temperature of the hot water.
During this process, small volumes of water evaporate, lowering the temperature of the water
that's being circulated throughout the cooling tower. In a short summary, a cooling tower

cools down water that gets over heated by industrial equipment and processes. The hot water
is usually caused by air conditioning condensers or other industrial processes. That water is
pumped through pipes directly into the cooling tower. Cooling tower nozzles are used to
spray the water onto to the "fill media", which slows the water flow down and exposes the
maximum amount of water surface area possible for the best air-water contact. The water is
exposed to air as it flows throughout the cooling tower. The air is being pulled by an motor-
driven electric "cooling tower fan".
In a wet cooling tower (or open circuit cooling tower), the warm water can be cooled to a
temperature lower than the ambient air dry-bulb temperature, if the air is relatively dry
(see dew point and psychrometrics). As ambient air is drawn past a flow of water, a small
portion of the water evaporates, and the energy required to evaporate that portion of the water
is taken from the remaining mass of water, thus reducing its temperature. Approximately 970
BTU of heat energy is absorbed for each pound of evaporated water (2 MJ/kg). Evaporation
results in saturated air conditions, lowering the temperature of the water processed by the
tower to a value close to wet-bulb temperature, which is lower than the ambient dry-bulb
temperature, the difference determined by the initial humidity of the ambient air. To achieve
better performance (more cooling), a medium called fill is used to increase the surface area
and the time of contact between the air and water flows. Splash fill consists of material placed
to interrupt the water flow causing splashing. Film fill is composed of thin sheets of material
(usually PVC) upon which the water flows. Both methods create increased surface area and
time of contact between the fluid (water) and the gas (air), to improve heat transfer.
Cooling towers are a very important part of many chemical plants. The primary task of a
cooling tower is to reject heat into the atmosphere. They represent a relatively inexpensive
and dependable means of removing low-grade heat from cooling water. The make-up water
source is used to replenish water lost to evaporation. Hot water from heat exchangers is sent
to the cooling tower. The water exits the cooling tower and is sent back to the exchangers or
to other units for further cooling.

WORKING SIDE PHOTOS
COMPRESSOR
MOTER AMMONIA PLANT
RECEIVER PHE

CHAPTER NO:-7 SELECTION OF PROJECT
The main hindrance to the utility dept. is its degradation of the equipment which is
constantly exposed to the environment. In case of transpek inc., it also experiencing
the same problem. On examining the plant, the major problem which prevails is the
frequent failures of condenser tubes. The effect of condenser tube failure impact the
plant in a great scale as it increased the shutdown time period of all unit is increased
and it also affect components of plant.
FIG : LEAK CONDENSER

Chapter no. 8 Results based on observation
• The corrosion behaviour of copper alloy depends on the resents of oxygen and other
oxidizers because it is cathodic to the hydrogen electrode.
• During the primary corrosion reaction of cuprous oxide film is produced that is
predominating responsible for the corrsion protection.
• The corrosion resistance of copper and copper base alloy in water is determined by
the nature of the naturally occurring and protective corrosion products film.

Problem Definition
Problem Definition : A condenser coil leak is a serious problem. It’s a very expensive
repair that can often result in the full replacement of your unit.
Problem Identification : A leak in your condenser coil will leak refrigerant, causing
your system to have less than the recommended charge (amount) of refrigerant in your
system. Not only is this a concern on it’s own, but it can lead to damage of other parts of your
system.
Problem Solution : Passivation is a non-electrolytic process typically using nitric or citric
acid which removes free iron from the surface and forms an inert, protective oxide layer that
in turn renders the stainless steel more rust-resistance due to lack of iron to react with the
atmosphere.

Chapter no. 9
9.1 Passivation
FIG. Passivation
Passivation refers to the spontaneous formation of an ultrathin film of corrosion products,
known as a passive film, on the metals’ surface that act as a barrier to further oxidation. The
chemical composition and microstructure of a passive film are different from the underlying
metal. Typical passive film thickness on aluminium, stainless steels, and alloys is within 10
nanometres. The passive film is different from oxide layers that are formed upon heating and
are in the micrometer thickness range – the passive film recovers if removed or damaged
whereas the oxide layer does not. Passivation in natural environments such as air, water and
soil at moderate pH is seen in such materials as aluminium, stainless steel, titanium,and
silicon.
Passivation is primarily determined by metallurgical and environmental factors. The effect of
pH is summarized using Pourbaix diagrams, but many other factors are influential. Some
conditions that inhibit passivation include high pH for aluminium and zinc, low pH or the
presence of chloride ions for stainless steel, high temperature for titanium (in which case the
oxide dissolves into the metal, rather than the electrolyte) and fluoride ions for silicon. On the
other hand, unusual conditions may result in passivation of materials that are normally
unprotected, as the alkaline environment of concrete does for steel rebar. Exposure to a liquid
metal such as mercury or hot solder can often circumvent passivation mechanisms.

9.2 How to
passivate
The term 'passivation' refers to treating metal with chemical baths in order to make them
permanently resistant to corrosion. In same cases, passivation is the name given to the
application of anti-corrosives (instead of a bath) to various metals. The process that is
used to passivate copper, however, is a little different, as there is no way to truly alter
this metal through chemical baths.
Passivation requires a neutral to slightly alkaline pH. Circulating passivation
chemicals with inhibitor should be circulated to have proper passive film.
Nevertheless, in order to change the metal surface from an active state to passive
state. The electrode potential must be raised to a level above that of the passivation
potential. Typically this is achieved by the use of PO4/polymers in the presence of
oxygen.
Obviously the cooling water must be circulated over the tower to the necessary
oxygen and heat load should be provided and chemical should be add accordingly.
During the process fans should be switched off.
The process for proper and effective passivation will need 3-4 days. Before the
regular treatment is employed pH should be not more than 7.0 – 7.5 for the efficient
use of chlorine or biocides.
The easiest way to passivate is to have min pressure of 2-3 kg /cm 2 of circulation
water for primary wash and then pass the coating by reducing it thickness by 100
ppm to 25 ppm, by this it take 4 day for each layer.

Chapter no. 10
10.1 Procedure of Passivation
Pre-cleaning
Systems hold up : 100 M3
Circulation rate : min pressure of circulation water is 2-3 Kg/CM2
Product : Ist Day Katscide 6423 100 ppm on hold up : 10 Kg
IInd Day Katscide 6565 100 ppm on hold up : 10 Kg.
Keep pH valued of circulating water 6.5-7.0 during Precleaning
Base of material : Non Oxidising Biocide with dispersant
Temp required (heat Load) : min 3-50C delta T of cooling tower
Give 10 Blow Down after Completion of Pre-cleaning and before starting Passivation
Passivation:-
System hold up : 100 M3
Circulation rate : min pressure of circulation water is 2-3 Kg/CM2
Product : 3rd Day Sofaid 4170 100 ppm on hold up : 10 Kg.
4rt Day Sofaid 4170 50 ppm on hold up : 05 Kg.
5th Day Sofaid 4170 35 ppm on hold up : 3.5 Kg.
6th Day Sofaid 4170 25 ppm on hold up : 2.5Kg.
Keep pH valued of circulating water 7.0-7.5 and No Blow down during Passivation
Base of material : Phosphonate Base Scale and Corrosion Inhibitor.
Temp required (heat Load) : min 2-40C delta T of cooling tower
Required time for Pre-cleaning and Passivation is 7 days.

10.2 Technical detail of material
KATS ORGANICS Corporation is a foremost Sole Proprietorship company which
is betrothed in manufacturing pure and qualitative Treatment Chemical and we
are trading of Water Testing Kits. Also we are engaged in offering Chemical Cleaning
Services, Hydro Jetting Services and Monitoring Services. We are an ISO 9001:2008
certified company that is established in the year 2011 with an aim of providing
qualitative chemicals as per the varied needs of the clients. We provide these chemicals
in diverse industries that such as Petro Chemicals, Fertilizers, Power Plants, Textile,
Pharmaceuticals, etc. Under the supervision of our Proprietor “Mr. Deepak Behare”, we
have gained tremendous success in this domain. Located at Vadodara (Gujarat, India),
we are supported by a team of capable professionals who are considered as the strongest
pillar of our firm.
Sofaid 4170
SOFAID -4170 series has high performance, treatment chemicals for cooling towers
having following advantages.
 Scale Inhibitor
 Corrosion Inhibitor
 Dispersant
 Bio-Dispersant
 Non-oxidisizing biocides
 Biocides
 Bacteriacides
 Algaecides.
 Fungicides
This company have special name of this product name Sofaid 4170.Which will cost 125
per kg. or approx.. Prices will discuss by authorities of both company.

10.3Costing
This company have special name of this product name Sofaid 4170.Which will cost 125
per kg. or approx..
Sofaid 4170 : 1.2 Kg./day
Katscide 6423 : 5.0
Kg./Week Katscide 6565
:5.0Kg./Week
Product Requirement Rate /Kg. Total Cost
Katscide 6423 10 185.00 1850.00
Katscide 6565 10 185.00 1850.00
Sofaid 4170 36 125.00 4500.00
Total Cost Per Month Rs. 8200.00
If required services for Pre-cleaning and passivation will be Charges Rs. 1500/day
ExtraGST @12% Extra

CHAPTER NO:-11
Advantages of passivation
 Passivation is a process that helps to prevent corrosion and pitting on surface.
 The passivation process applies a thin transparent passive chemically inter film
to stainless steel that reduce the reactivity of the metal.
 This film deters corrosion and oxidation.
 For this plant since the load is decreased due to ageing it is not necessary to
increase the number of tube.
 Due to this process tube life is increase so that change of new tube is delay
so productivity will increase.
 Maintenance work will reduce.

CHAPTER NO:-12
OBJECTIVE
 To reduce workload of Workers at maintenance, due to this time has save.
 To analyse of the causes for the condenser tube failures
 To determine the modes of failures
 To provide the best suitable optimization needed for the plant.
 Because of comparing the other company price so we can say tis project will
save money.

CHAPTER NO:- 13
REFERENCES
 https://en.m.wikipedia.org/wiki/Refrigeration
 https://store.danfoss.com
 https://youtu.be/peVAaLIJJ6c
 https://en.m.wikipedia.org/wiki/Passivation_(chemistry
 https://neilorme.com/AEV.shtml
 http://files.danfoss.com/technicalinfo/dila/01/PF000F202.pdf
 https://www.graphicproducts.com/articles/ammonia-
refrigeration-fundamentals/
 Engineering youtube videos

Thank you

Harsh2155

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