Venturi Scrubber from Perry, CEHB, VII

check this web site for costs of scrubbers

widely used types of particulate scrubbers. The designs have becomegenerally standardized, and units are manufactured by a large numberof companies. Venturi scrubbers may be used as either high- or lowenergydevices but are most commonly employed as high-energyunits. The units originally studied and used were designed to the proportionsof the classical venturis used for metering, but since it wasdiscovered that these proportions have no special merits, simpler andmore practical designs have been adopted. Most “venturi” contactorsin current use are in fact not venturis but variable orifices of one formor another. Any of a wide range of devices can be used, including asimple pipe-line contactor. Although the venturi scrubber is not inherentlymore efficient at a given contacting power than other types ofdevices, its simplicity and flexibility favor its use. It is also useful as a

http://www.matche.com/EquipCost/Index.htm

Venturi Scrubbers The venturi scrubber is one of the most

gas absorber for relatively soluble gases, but because it is a cocurrentcontactor, it is not well suited to absorption of gases having low solubilities.Current designs for venturi scrubbers generally use the verticaldownflow of gas through the venturi contactor and incorporate threefeatures: (1) a “wet-approach” or “flooded-wall” entry section, to avoiddust buildup at a wet-dry junction; (2) an adjustable throat for the venturi(or orifice), to provide for adjustment of the pressure drop; and(3) a “flooded elbow” located below the venturi and ahead of theentrainment separator, to reduce wear by abrasive particles. The venturithroat is sometimes fitted with a refractory lining to resist abrasionby dust particles. The entrainment separator is commonly, but notinvariably, of the cyclone type. An example of the “standard form” ofventuri scrubber is shown in Fig. 17-48. The wet-approach entry sectionhas made practical the recirculation of slurries. Various forms ofadjustable throats, which may be under manual or automatic control,duct of some other shape forms the gas-liquid-contacting zone. Thegas stream flowing at high velocity through the contactor atomizes theliquid in essentially the same manner as in a venturi scrubber. However,the liquid is fed into the contactor and later recirculated fromthe entrainment separator section by gravity instead of being circulatedby a pump as in venturi scrubbers. The scheme is well illustratedin Fig. 17-49a. A great many such devices using contactor ducts ofvarious shapes, as in Fig. 17-49b are offered commercially. Althoughself-induced spray scrubbers can be built as high-energy units andsometimes are, most such devices are designed for only low-energyservice.The principal advantage of self-induced spray scrubbers is the eliminationof a pump for recirculation of the scrubbing liquid. However,the designs for high-energy service are somewhat more complex andless flexible than those for venturi scrubbers.Plate Towers Plate (tray) towers are countercurrent gasatomizedspray scrubbers using one or more plates for gas-liquid contacting.They are essentially the same as, if not identical to, the devicesused for gas absorption and are frequently employed in applications inwhich gases are to be absorbed simultaneously with the removal ofdust. Except possibly in cases in which condensation effects areinvolved, countercurrent operation is not significantly beneficial indust collection.The plates may be any of several types, including sieve, bubble-cap,and valve trays. The impingement baffle plate (Fig. 17-50) is commonlyused for dust collection applications. Impingement on the bafflesis not the controlling mechanism of particle collection; theprincipal collecting bodies are the droplets produced from the liquidby the gas as it flows through the perforations and around the baffles.The slot stage (Fig. 17-50) is in effect a miniature venturi contactor.Valve trays constitute multiple self-adjusting orifices that providenearly constant gas pressure drop over considerable ranges of variationin gas flow. The gas pressure drop that can be taken across a singleplate is necessarily limited, so that units designed for highcontacting power must use multiple plates.Plate towers are more subject to plugging and fouling than venturitype

scrubbers that have large passages for gas and liquid.Packed-Bed Scrubbers Packed-bed scrubbers of the types usedfor gas absorption may also be used for dust collection but are subjectto plugging by deposits of insoluble solids. Random packings, such asdumped Raschig rings and Berl saddles, are most seriously affected byplugging. Regular packings, such as stacked grids, are better in dustcollectionservice. When both a gas and particulate matter are to becollected, it is advisable to use a primary-stage scrubber of the venturior similar type to collect the particulate matter ahead of a packed gasabsorber.Packed-bed scrubbers may be constructed for either vertical orhorizontal gas flow. Vertical-flow units (packed towers) commonly usecountercurrent flow of gas and liquid, although cocurrent flow issometimes used. Packed scrubbers using horizontal gas flow usuallyemploy cross-flow of liquid.Scrubber packings are too large to serve as collecting bodies for anyexcept very large dust particles. In the collection of fine particles, thepackings serve primarily to promote fluid turbulence that aids thedeposition of the dust particles on droplets. In a packed tower operatingbelow the flooding point, with most of the liquid flowing in filmsand little spray formation, the relative efficiency in collection of particlesmay possibly be lower than that of a venturi-type scrubber operatingat the same contacting power. However, no data are available toresolve the question.Mobile-Bed Scrubbers Mobile-bed scrubbers (Fig. 17-51) areconstructed with one or more beds of low-density spheres that are freeto move between upper and lower retaining grids. The spheres arecommonly 1.0 in (2.5 cm) or more in diameter and made from rubberor a plastic such as polypropylene. The plastic spheres may be solid orhollow. Gas and liquid flows are countercurrent, and the sphericalpackings are fluidized by the upward-flowing gas. The movement ofFIG. 17-48 Venturi scrubber. (Neptune AirPol.)

Fig 17-48

Fig 17-49

Fig 17-50

Croll Reynolds Scrubbers

http://www.environmental-center.com/technology/croll/scrubber.htm#jvs

http://www.matche.com/EquipCost/Index.htm

5) Venturi Gas Scrubber Extracted from Misc Equipment Items

gives a start for cost of a venturi scrubbers

High Energy Venturi Scrubbers & SystemsHigh energy venturi scrubbers are used for control of fine particles in the size range of one micron and smaller.A gas side pressure drop is used to provide intimate contact between the particles in the gas and the scrubbing liquid. A higher gas side pressure drop will remove smaller particles from the gas. For varying gas rates, variable throat designs are available to maintain the pressure drop needed for effective control of the particles. Skid mounted package systems including a cyclonic separator with liquid storage, a recirculation pump,and piping reduce the amount of makeup liquid required. System blowers can also be included.

Richardson (100-115) gives a method to size venturi gas scrubbers. An example is included.

Gas capacities range from 225 to 189,800 acfm.

General Description. Note The scrubber in Richardson looks as follows

The WH High Energy Scrubber is a high pressure drop, very high efficiency wet dust collectorwith an adjustable throat venturi.

Tangentisl inlet. Cyclone droplet eliminator (See KO pot folder for cyclone method).Slurry drain.

Sketch is given with Principles of operation.

Engineering and Application data is presented.

Procedure for selecting a WH High Energy Venturi Scrubber is presented.

From the data presented you can predict the performance of a WH High Energy Venturi Scrubber.

From this data you can estiate the cost of a venturi scrubber.

More Details aon the Procedure For Selecting a WH High Energy Venturi Scrubber

Page 110-115 page 4 gives the nomenclature for the Engineering and Application Data

Step 1 To maintain maximum scrubbing efficiency, it is desirable to minimize liquid evaporation in the Contactorsection of the scrubber. For this reason, hot gases should be pre-cooled to about 250 to 300F aheadof the scrubber inlet. Performance calculations should be based on the assumption that hot gas temperature(and gas volume, gas density and gas viscosity) has been reduced to the 250 to 300F range.

http://www.matche.com/EquipCost/Index.htm

http://www.estcorporation.com/wetscrub.htm

Step 2 Refer to the drawings on page 10 and 11, select the standard size scrubber, N, ( a dimensionless Scrubber Size)having a capacity range which incldes the gas volume at the scrubber inlet. If system requirements areaccurately established, and not subject to change, a special size may be selected by:

3.41(Q)^0.5 <= N <= 4.32(Q)^0.5 Equation (2)

where Q = volumetric flow rate of the gas at the scrubber inlet, actual cubic feet per minute, acfm

one selects the WH size from the Table on page 11 and from the size various dimensions are provided.

Note: the Table on page 11 gives sizes as WH 65 to WH 1450. The N value is the numericalcomponent of the size designation. That is, WH 1450 is, in fact, N = 1450 for use in other Figures.

Step 3 Select a first trial pressure drop, dP. In venturi scrubbers, collection efficiency increases as an exponential function of thepressure drop. Judgement and experience are required to select an adequate first trial value.As a giude, some typical applications and the required pressure drops are:

Application Pressure Drop, dP, Inches of Water Column

Aluminum Smelter 20 - 25" w.c.Asphalt Plant 24 - 35" w.c.Boiler or Furnace Ash or Soot 55 - 63" w.c.Cupola (Iron Foundry) 55 - 80" w.c.Lime Kiln 23 - 27" w.c.Magnesium Ore Roaster 12 - 20" w.c.Oil Fumes and Condensates 39 - 47" w.c.Zinc Smelter 20 - 35" w.c.

Step 4 Estimate the rate of circulating (unevaporated) scrubbing liquid supplied to the scrubber.To avoid liquid carryover or system pulsations, scrubbing liquid rates must be maintained within certain limits.At any given pressure drop, scrubber efficiency increases as a function of the quantity of scrubbing liquid supplied.Thus, since water (or other srubbing liquids) and the equipment required to supply it are relatively inexpensivecompared to fan horsepower, it is generally desirable to use values near or equal to the maximum values determinedherein. The total scrubbing liquid rate consists of three (3) components:

Step 4a R1 is the liquid rate supplied directly to the Venturi Throat and Contactor Section.The minimu value for R1 determined from Fig 1, page 6.The maximu value for R1 determined from Fig 2, page 6.

Step 4b R2 is the liquid supplied indirectly to the Contactor by means of a large orifice, solid cone nozzle directly belowthe Contactor section. R2 is found by:

(0.05)(R1) <= R2 <= (0.2)(R1) Equation (3)

Step 4c R3 is the liquid rate required to clean the spinner vanes in the Droplet Eliminator. It is supplied by means ofa large orifice hollow cone nozzle directly above the Drop Eliminator. R3 is found by:

R3 = 12.078)(N) / Q Equation (4)

Step 4d Calculate W1, flow rate of liquid supplied to upper liquid connection, not including evaporation losses,

U.S. gallon per minute

For N <= 800 W1 = (R1)(Q) / 1000 Equation 5a

For N > 800 W1 = (2)(R1)(Q) / 3000 Equation 5b

Step 4e Calculate W2, flow rate of liquid supplied to lower liquid connection. Not including evaporation losses,U.S. gallons per minute

For N <= 800 W2 = (R2 + R3)(Q) / 1000 Equation 6a

For N > 800 W2 = (R1/3 + R2 + R3)(Q) / 1000 Equation 6b

Note The use of W1 and w2 will be found in Step 8 where you will determine the evaporation losses.

Step 5 Establish the fractional efficiency curve based on the trial value of dP for the scrubber size NESTABLISHED IN Step 2 and 3. A dimensionless parameter, F, is calculated by:

F = {(0.003144)(dP) / Dg} [ (R1 + R2)^0.4571 ][ (S/Ug)^0.2857 ] Equation 7

R1 and r2 were found in Steps 4

Dg is the gas density in lb/cf

ug is the gas viscosity at the Collector inlet in lb/ft-sec

S is the true specific gravity of the dust at the collector inlet, equal to the true density in grams per cc

The fractional efficiency is found by use of Fig 3 on page 7

Step 6 Calculate the total collection efficiency, Et, by means of Equation 1, page 4

Ste 7 If Et is either too low or higher than required to meet emission levels, reduce or increase the trial value of dPand/or increase r1 and R2 and repeat steps 4 to 6.

Step 8 The gas will leave the scrubber saturated or nearly so. The liquid rates W1 and w2 found in step 4 do not include evaporation losses. These must be calculated by psychometrics and addedproportionally to W1 and w2

A complete example is given for students to follow.

Note To solve the efficiency one must have the particulate conditions at the collector inlet.This will be typically as follows:

n Dp (microns) Pn % finer1 0.1 52 0.14 103 0.2 17.34 0.25 25.7

5 0.3 32.86 0.36 407 0.45 49.88 0.55 58.59 0.65 65.5

10 0.75 74.511 1.2 85.612 2 9513 4 99.14

If you do not have this data, you cannot solve the efficiency part of the design.You may have to assume this particulate condition simply to demonstrate the method.

Flange types

Van Stone Flanges are often used in Srubbers. Check the above web site for a description of several types of flanges.They are often used to connect plastic PVC pipe to metal pipes with standard flanges.

http://progdev.sait.ab.ca/pwen220/042/piping3.htm

High energy venturi scrubbers are used for control of fine particles in the size range of one micron and smaller.A gas side pressure drop is used to provide intimate contact between the particles in the gas and the scrubbing liquid. A higher gas side pressure drop will remove smaller particles from the gas. For varying gas rates, variable throat designs are available to maintain the pressure drop needed for effective control of the particles. Skid mounted package systems including a cyclonic separator with liquid storage, a recirculation pump,and piping reduce the amount of makeup liquid required. System blowers can also be included.

R1 R2R3

Slurry Drain

Clean Gas Out

See actual dimensions in Richardsonpage 10 of 100-115

Richardson No. = 100-115

To maintain maximum scrubbing efficiency, it is desirable to minimize liquid evaporation in the Contactorsection of the scrubber. For this reason, hot gases should be pre-cooled to about 250 to 300F aheadof the scrubber inlet. Performance calculations should be based on the assumption that hot gas temperature(and gas volume, gas density and gas viscosity) has been reduced to the 250 to 300F range.

http://www.estcorporation.com/wetscrub.htm

Refer to the drawings on page 10 and 11, select the standard size scrubber, N, ( a dimensionless Scrubber Size)having a capacity range which incldes the gas volume at the scrubber inlet. If system requirements are

where Q = volumetric flow rate of the gas at the scrubber inlet, actual cubic feet per minute, acfm

one selects the WH size from the Table on page 11 and from the size various dimensions are provided.

Note: the Table on page 11 gives sizes as WH 65 to WH 1450. The N value is the numericalcomponent of the size designation. That is, WH 1450 is, in fact, N = 1450 for use in other Figures.

Select a first trial pressure drop, dP. In venturi scrubbers, collection efficiency increases as an exponential function of thepressure drop. Judgement and experience are required to select an adequate first trial value.

To avoid liquid carryover or system pulsations, scrubbing liquid rates must be maintained within certain limits.At any given pressure drop, scrubber efficiency increases as a function of the quantity of scrubbing liquid supplied.Thus, since water (or other srubbing liquids) and the equipment required to supply it are relatively inexpensivecompared to fan horsepower, it is generally desirable to use values near or equal to the maximum values determined

R2 is the liquid supplied indirectly to the Contactor by means of a large orifice, solid cone nozzle directly below

R3 is the liquid rate required to clean the spinner vanes in the Droplet Eliminator. It is supplied by means of

Calculate W1, flow rate of liquid supplied to upper liquid connection, not including evaporation losses,

Calculate W2, flow rate of liquid supplied to lower liquid connection. Not including evaporation losses,

The use of W1 and w2 will be found in Step 8 where you will determine the evaporation losses.

Establish the fractional efficiency curve based on the trial value of dP for the scrubber size N

Equation 7

S is the true specific gravity of the dust at the collector inlet, equal to the true density in grams per cc

If Et is either too low or higher than required to meet emission levels, reduce or increase the trial value of dP

The gas will leave the scrubber saturated or nearly so. The liquid rates W1 and w2 found in step 4 do not include evaporation losses. These must be calculated by psychometrics and added

Van Stone Flanges are often used in Srubbers. Check the above web site for a description of several types of flanges.

From Richardson 100-115, page 11Given: Gas Conditions at Collector Inlet

Table of capacities, Dimensions and Weights by Fisher - Klosterman Inc.Gas temp =

acfm acfm length " Radius " max acfm R.H. =Size N Max Min. A E Selector Q, acfm =WH - 65 65 360 225 28 5 Dg =WH - 80 80 550 340 34.375 6 Ug =WH - 100 100 860 535 43 7 S =WH - 120 120 1235 770 51.625 8.5 Year =WH - 150 150 1935 1205 64.5 10 Mtl (1 to 4)WH - 180 180 2785 1735 77.375 12 Cdn $ exchange =WH - 210 210 3790 2360 90.375 13.5WH - 250 250 5375 3345 107.5 15.5 Step 2 Max =WH - 300 300 7740 4820 129 18 Min. =WH - 350 350 10535 6560 150.5 21.5 N =WH - 400 400 13760 8570 172 24 Size =WH - 450 450 17415 10850 193.5 27.5 Length =WH - 500 500 21500 13395 215 31 Diam. =WH - 550 550 26015 16205 236.5 33.5WH - 600 600 30960 19290 258 36 Step 3 Assume a trial value pressure drop = 30 inches w.c.WH - 650 650 36330 22635 279.5 39WH - 700 700 42140 26255 301 42 Step 4a R1 minimum =WH - 800 800 55035 34290 344 47 R1 maximum =WH - 900 900 69655 43400 387 53 69655WH - 1000 1000 85895 53580 430 58 85895 Select R1 just under R1 maximum =WH - 1100 1100 104055 64835 473 63 104055WH - 1200 1200 123835 77160 516 69 123835 Step 4b 0.05(R1) =WH - 1300 1300 145335 90555 559 74 145335 0.2(R1) =WH - 1450 1450 180810 112660 623.5 87 180810

Select R2 = just under 0.2(R1) =

Step 4c By eqn 4, R3 = 12.078(N) / QBy eqn 4, R3 =

Fig 1 for 30 inches w.c. dP and N > 800

N R1 R1 calc800 1.65 1.63900 1.6 1.60

1000 1.55 1.571100 1.52 1.531200 1.5 1.501300 1.48 1.471450 1.42 1.42

700 800 900 1000 1100 1200 1300 1400 15001

1.11.21.31.41.51.61.71.81.9

2

f(x) = − 0.000332 x + 1.898787

dP = 30 " w.c. for N > 800

Column BLinear (Column B)

Scrubber Size, N

R1

min

imum

, Gal

/100

0 ac

fm

Fig 1 for 50 inches w.c. dP and for N > 800

N R1 R1 calc800 3 3.00900 2.95 2.95

1000 2.9 2.901100 2.85 2.851200 2.8 2.801300 2.75 2.751450 2.685 2.68

Figure 2 for 30" w.c. and N > 800

N R1 max R1 calc800 4.01 4.01900 4.03 4.03

1000 4.055 4.051100 4.075 4.081200 4.1 4.101300 4.12 4.121450 4.15 4.15

700 800 900 1000 1100 1200 1300 1400 15001

1.11.21.31.41.51.61.71.81.9

2

f(x) = − 0.000332 x + 1.898787

dP = 30 " w.c. for N > 800

Column BLinear (Column B)

Scrubber Size, N

R1

min

imum

, Gal

/100

0 ac

fm

700 800 900 1000 1100 1200 1300 1400 15002.5

2.6

2.7

2.8

2.9

3

3.1

f(x) = − 0.000489 x + 3.389268

Fig 1 for R1 at 50 " w.c. for N > 800

Column BLinear (Column B)

Scxrubber Size, N

R1 M

inim

um, G

al/1

000

acfm

700 800 900 1000 1100 1200 1300 1400 15003.9

3.95

4

4.05

4.1

4.15

4.2

f(x) = 0.000218 x + 3.835446

Fig 2 for R1 Max when N > 800

Column BLinear (Column B)

Scxrubber Size, N

R1 m

ax, G

al/1

000

acfm

Given: Gas Conditions at Collector Inlet

125 F Gas does not require pre-cooling10%

68,500 lb/hr = 266,328 0.0648 lb/cf

1.25E-05 lb mass/ft- cP = 1.86E-022 true specific gravity of solids centipoise

20031 12 ga HRS cs Construction

1.6 To convert to CDN $

69,655 acfm 43,400 acfm

900 nominal size Calcs only good when N . 800WH - 900 Fisher - Klosterman Inc nomenclature

32.25 ft. approx see Richardson page 108.8 ft. approx see Richardson page 10

Assume a trial value pressure drop = 30 inches w.c. 1.0836 psi

R1 minimum = 1.6 Fr Fig 1 see curve fit belowR1 maximum = 4.0 Fr Fig 2 see curve fit below

Select R1 just under R1 maximum = 3.8 U.S. Gal/1000 acfm

0.05(R1) = 0.19 Eqn 30.76 Eqn 3

Select R2 = just under 0.2(R1) = 0.75 U.S. Gal/1000 acfm

By eqn 4, R3 = 12.078(N) / QBy eqn 4, R3 = 0.16 U.S. Gal/1000 acfm

700 800 900 1000 1100 1200 1300 1400 15001

1.11.21.31.41.51.61.71.81.9

2

f(x) = − 0.000332 x + 1.898787

dP = 30 " w.c. for N > 800

Column BLinear (Column B)

Scrubber Size, N

R1

min

imum

, Gal

/100

0 ac

fm

700 800 900 1000 1100 1200 1300 1400 15001

1.11.21.31.41.51.61.71.81.9

2

f(x) = − 0.000332 x + 1.898787

dP = 30 " w.c. for N > 800

Column BLinear (Column B)

Scrubber Size, N

R1

min

imum

, Gal

/100

0 ac

fm

700 800 900 1000 1100 1200 1300 1400 15002.5

2.6

2.7

2.8

2.9

3

3.1

f(x) = − 0.000489 x + 3.389268

Fig 1 for R1 at 50 " w.c. for N > 800

Column BLinear (Column B)

Scxrubber Size, N

R1 M

inim

um, G

al/1

000

acfm

700 800 900 1000 1100 1200 1300 1400 15003.9

3.95

4

4.05

4.1

4.15

4.2

f(x) = 0.000218 x + 3.835446

Fig 2 for R1 Max when N > 800

Column BLinear (Column B)

Scxrubber Size, N

R1 m

ax, G

al/1

000

acfm

If the particle distribution of the solids in the feed is known, the collector efficiency can be determined as follows:

Step 6Dp(n) % Finer Dp mid Ep mid Ep mid *

n microns Pn microns Fig 3 P(n+1) - Pn P(n+1) - Pn1 0.1 5.00% 0.10 47 5.00% 2.352 0.14 10.00% 0.12 49.5 5.00% 2.483 0.2 17.30% 0.17 72.2 7.30% 5.274 0.25 25.70% 0.23 86 8.40% 7.225 0.3 32.80% 0.28 92.4 7.10% 6.566 0.36 40.00% 0.33 96 7.20% 6.917 0.45 49.80% 0.41 98.3 9.80% 9.638 0.55 58.50% 0.50 99.35 8.70% 8.649 0.65 65.50% 0.60 99.74 7.00% 6.98

10 0.75 74.50% 0.70 99.89 9.00% 8.9911 1.2 85.60% 0.98 99.95 11.10% 11.0912 2 95.00% 1.60 100 9.40% 9.4013 4 99.14% 3.00 100 4.14% 4.14

100.00% 100 0.86% 0.86Required collection efficiency = 90% Et = 90.54% Step 6

Step 5 Calculate F by Equation 7 Step 7 Efficiency, Et, meets requirement.

F = 0.003144(dP)/Dg [ (R1 + R2)^0.4571][(S/Ug)^0.2857] Equation 7

dp = 30 inches w.c.Dg = 0.0648 lb/cfR1 = 3.8R2 = 0.75

S = 2Ug = 1.25E-05 lb mass/ft-sec

F = 89.25 for use in Fig 3

If the particle distribution of the solids in the feed is known, the collector efficiency can be determined as follows:

Efficiency, Et, meets requirement.

Evaporation Losses are calculated as follows:

From Step 4 and Inut Data

Pressure = 14.696 psiaTemp = 125 FRH = 10%R1 = 3.8R2 = 0.75R3 = 0.16Q = 68500 acfmDg = 0.0648 lb/cf

For N > 800 W1 = (2)(R1)(Q) / 3000 For N <=800, W1 = (R1)(Q) / 1000 Eqn 5b

W1 = 173.5 usgpm liquid supplied to upper liquid connection, not including evaporation losses.

For N > 800 W2 = (R1/3 + R2 + R3)(Q) / 1000 Eqn 6b

W2 = 149.0 usgpm liquid supplied to lower liquid connection, not including evaporation losses.

Calculation of the evaporation losses involves pscchometric analysis as follows: See Air Density V1.1 in Phys Property Folder

Calc the lbs of water per pound of dry air at 125F.

Basis V. Ganapathy, Hydroc Pr, May 1989, P-69Satd Vap Press = 0.08+0.000000281(°F)^3.25 a curve fit of vapor pressure data

Sat'd vapour pressure, SVP = 1.915117 psia by eqn 10

At RH = 10% partial Pressure pw = 0.191512 psia by pw = (RH)(SVP)

moles water / moles dry air = = pw / (Po-pw)

moles water / moles dry air = 0.013204 by eqn 11

For dry air at 21% O2 and 79% N2 the MW = 28.84For water, the MW = 18

lbs water per lb dry air = 0.008241 by moles water * 18 / moles dry air / MW dry air = 28.84

From the psychometric chart, the corresponding web bulb temperature is 76.4 F

At 76.4 thew SVP = 0.450476 psia by eqn 10

Moles water / moles dry air = = SVP / (Po - SVP) = 0.031622

lbs water per lb dry air = 0.019737

Weight of dry air = 4402.52 lb dry air min. by Eqn 11

Evaporation losses = 6.1 u.s. gpm

W1' = 176.8 U.S. gpm

W2' = 151.8 U.S. pgm

liquid supplied to upper liquid connection, not including evaporation losses.

liquid supplied to lower liquid connection, not including evaporation losses.

See Air Density V1.1 in Phys Property Folder

Eqn 10

Eq 11

by moles water * 18 / moles dry air / MW dry air = 28.84

see Perry VI, page 12-5

Cost Richardson 100-115 1988Mtl =

Mat'l class (1 to 4) = 1 2 3 4 Size =12 ga - NRS 1/4" - NRS 12 ga 1/4" wt man hrs Year =

Size N cs cs 304 ss 304 ss lbs install Cdn Ex =WH - 65 65 $3,286 $3,795 $3,849 $4,563 35 8WH - 80 80 $3,480 $4,001 $4,104 $4,935 50 8 1988WH - 100 100 $3,707 $4,295 $4,466 $5,477 80 8 2003WH - 120 120 $3,966 $4,611 $4,865 $6,091 110 8WH - 150 150 $4,391 $5,137 $5,529 $7,148 170 16 1WH - 180 180 $4,853 $5,721 $6,274 $8,358 245 16 2WH - 210 210 $5,579 $6,586 $7,376 $9,989 420 16 3WH - 250 250 $6,301 $7,527 $8,584 $12,032 595 16 4WH - 300 300 $7,308 $8,856 $10,301 $13,684 855 24WH - 350 350 $8,411 $10,328 $11,596 $16,571 1,165 24 2003WH - 400 400 $9,813 $12,146 $13,777 $20,031 1,520 24WH - 450 450 $11,106 $13,908 $15,486 $22,486 2,615 24WH - 500 500 $12,511 $15,826 $17,693 $25,934 3,230 32WH - 550 550 $13,994 $17,874 $20,047 $29,653 3,905 32WH - 600 600 $15,650 $20,137 $22,485 $33,720 4,650 32WH - 650 650 $17,322 $22,315 $25,003 $37,994 5,455 32WH - 700 700 $19,087 $24,632 $27,672 $42,541 6,325 48WH - 800 800 $22,945 $29,878 $33,727 $52,721 8,260 48WH - 900 900 $26,854 $35,400 $40,097 $62,939 10,455 64 2003WH - 1000 1000 $31,173 $41,501 $47,126 $74,396 12,910 64WH - 1100 1100 $35,840 $48,119 $54,481 $86,878 21,030 96WH - 1200 1200 $40,752 $54,854 $62,140 $100,293 25,025 96 2003WH - 1300 1300 $46,092 $62,045 $70,430 $114,392 29,370 128WH - 1450 1450 $54,412 $73,665 $83,850 $137,345 36,540 128

2003Fabricated Equipment Index

Year FEI1975 192.21976 200.81977 216.61978 238.61979 261.71980 291.61981 321.81982 327.51983 330.11984 335.41985 335.61986 337.71987 344.1 Escalation.1988 361.3 1.051989 379.4 1.051990 398.3 1.051991 418.3 1.051992 439.2 1.051993 461.1 1.051994 484.2 1.051995 508.4 1.05

1996 533.8 1.051997 544.5 1.021998 555.4 1.021999 566.5 1.022000 577.8 1.022001 589.4 1.022002 601.2 1.022003 613.2 1.022004 625.4 1.022005 638.0 1.022006 650.7 1.022007 663.7 1.02

1 12 ga - NRS cs900

20031.6 assume no duty per NAFTA

Base FEI = 361.3Escalated FEI Index = 613.2

12 ga - NRS cs $26,854 19881/4" - NRS cs $35,400 198812 ga 304 ss $40,097 19881/4" 304 ss $62,939 1988

Purchased Cost, Cdn $ = $72,920F.O.B Louisville, KentuckyShipping weight = 10455 lbs

Shipping Rates for 1000 miles, Class 100 for scrubbersRichardson 100-700 $18.86 per 100 wt.

Cdn $ Shipping = $5,354

Purchased Cost, Cdn $ = $78,274FOB Plant Site

Installation Hrs = 64Crew rate = 2003 $50.00 $/hr CdnInstallation Cost $3,200 $, Cdn

Total Installed Cost = $81,474 $ Cdn