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ChBE 2523 Separations

Chapter 10Psychrometric Charts

Spring, 2015

Dr. John Clay

Yesteray yo!

sai tomorro".

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#n a $ighter Sie

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C%&P'E( ) '#P*CS

Drying Overview (9.1, 9.4)Psychrometric Charts (9.3)

Drying Calculations (9., 9.!, 9.")

#y$es o% Dryers (9.2)

Brea+ !p chapter into o!r ierent slie sets

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-oals o $ect!re

&ntro'uce (or review) $sychrometric chartsDi%%erentiate etween the %our 'e%initions o%

humi'ity an' calculate each

se $sychrometric charts to solve 'rying$rolems

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'emperat!res

Dry ul tem$erature, ##em$erature %rom unmo'i%ie' tem$erature sensor

O%ten rea' as *tem$erature+

et ul tem$erature, #w

-tea'ystate none/uilirium tem$erature otaine'when small amount o% water is contacte' un'er

a'iaatic con'itions %rom a small stream o% gas

# 0 (umi'ity) remain constant

Dew $oint tem$erature, #'$#em$erature at which the air ecomes saturate' with

water va$or

Con'ensation will occur i% the moisture content o% the air

stays constant an' the tem$erature 'ro$s elow the'ew oint tem erature

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%!miity

review o% humi'ityumi'ity, g o% water va$or containe' in 1g o%

'ry air

-aturate' humi'ity, s

umi'ity level i% the air was saturate',$$s

Percentage humi'ity, $Com$arison o% the actual humi'ity, ,

to the saturate' humi'ity, s

Percentage relative humi'ity, 5umi'ity re$orte' in terms o% relative

$ressures

& re$ort

5

!

== airdrykg

OHkgMM

pPpH

air

water

A

A 2

=

=airdrykg

OHkg

M

M

pP

pH

air

water

As

Ass

2

s

pH

HH 100=

As

AR

p

pH 100=

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%!miity Deinitions

"

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%!miity Charts

umi'ity ($sychrometric) charts6our charts to choose %rom

#e7t

Carrier

aon 8 -&

aon nglish

hy %our charts:

nits-cale

Detail

;

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nother source o% v'ata

hat is 'ry ul

tem$erature:

6igure ;.41, $. 3; 9

%!miity Charts

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hat is asolute humi'ity:

solute umi'ity is to mass %raction (7)

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