evaporative cooling & humidification

7/30/2019 Evaporative Cooling & Humidification

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EVAPORATIVE COOLING

AND HUMIDIFICATION

Aquino, Kazandra M.

Magtrayo, Charlette Ritz O.

Samson, Jericko L.

San Jose, John Kevin G.


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THEORY

The basic principle of the cooling tower operation is that of evapora

condensation and exchange of sensible heat.

The air and water mixture releases latent heat of vaporization which

cooling effect on water by turning a certain amount of liquid into its

state thereby releasing the latent heat of vaporization.

The air stream releases latent heat of vaporization thereby dropping

temperature of the water.


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THEORY

The liquid changing to its vaporous state consumes heat which is tak

the water remaining, thus lowering its temperature.

There is a penalty involved, and that is loss of water which goes up t

cooling tower and is discharged into the atmosphere as hot moist vap

Under normal operating conditions, this amounts to approximately 1

each 10 oF cooling range.


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THEORY

Sensible heat that changes temperature is also responsible for part of

coolingtowers operation. When water is warmer than the air, there i

tendency for the air to cool the water. The air then gets hotter as it g

sensible heat of the water and the water is cooled as its sensible heat

transferred to the air.

Approximately 25% of the sensible heat transfer occurs in the tower

the balance of the 75% cooling is due to the evaporative effect of la

of vaporization.


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THEORY


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OBJECTIVES

To apply the principles of humidification and

evaporative cooling in the shell-and-tube heat exchanger-cooling t

network in the laboratory.


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OBJECTIVES

To study the parts of an induced draft, counterflow

cooling tower and their uses.

To estimate the number of transfer units and

height of a transfer unit of the tower.


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ANALYTICAL BALANCE


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MOVABLE LADDER


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EQUIPMENT/MATERIALS


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cooling tower and shell-and-tube heat exchange

network and accessories


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DIGITAL TIMER


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DIGITAL THERMOMETER


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100 mL Beaker


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TAPE MEASURE


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THERMO-HYGRO-ANEMOMET


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BOILER


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HEAT EXCHANGER


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WATER TANK


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COOLING TOWER


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SWITCHES


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BOILER UNIT


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SET UP


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PROCESS FLOW


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PROCEDURE

START UP1. Check for debris in the tower , air discharge area, catch basin.

2.Open drain hole and flush the basin with clean water

3. Measure the tower diameter and height of packing

4.Open windows and exhaust fans for proper ventilation5. Switch fan motor to attain steady state air flow in the tower

6. Open header valve and discharge valve to the tank

7. Close drain valve. Open it prior to the main experiment


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MAIN EXPERIMENT

1. When the heat exchanger reaches steady state condition ( constant flu

and pressure), allow water to enter the cooling tower by closing the drai

2. Gather and tabulate data.

(air conditions, water conditions and flowrates)

3. Repeat step 2 in 10 minute intervals until steady state is attained.

(0.5 difference on 3 consecutive data)

PROCEDURE


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SHUTDOWN1. Continue the circulation of water until all the steam in the pipeline

condensed.

2. Wait until all the water in the system was discharged to the catch baSwitch off the fan , unplugged from power source

3. Open drain valves to ensure that no entrained water remains in the

PROCEDURE


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evaporative cooling & humidification

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