Raschig Super-Rings341789233.online.de/editor/assets/Info RASCHIG Super-Ring-250.pdf · above. The...

Raschig Super-Ring

Product Bulletin 250

The development of the new „Raschig Super-Ring“ packing elementsets new standards in the field of separation technology, as thedesigners of the Raschig Super-Ring have succeeded in finding anoptimum link to those demands which a modern, high-performancepacking element must fulfil under industrial conditions.

Superior performance by designTM

RASCHIG GMBHRASCHIG USA Inc.

RASCHIG GMBHProf. Dr.-Ing. Michael SchultesMundenheimerstr 100

RASCHIG USA Inc.Mr. Bill Kennard2201 East Lamar Blvd # 240Mundenheimerstr. 100

D-67061 Ludwigshafenphone.: +49 (0)621 56 18 - 648fax: +49 (0)621 56 18 - 627e-maill: [email protected] www.raschig.com

2201 East Lamar Blvd # 240Arlington, TX 76006 ,USAwww.Raschig.com/Ringsphone: 001 817-695-5691 fax: 001 817-695-5697e-mail: [email protected]

Raschig Super-Ring

Subject page

Introduction 1

Performance data 2-3

Compensation for the decrease in Compensation for the „decrease in

volume“ for dumped packings 4

Pressure drop 5-8

Transfer efficiency 9-12

Height of a transfer unit HTUOV 13-16g OV

Liquid hold-up in columns 17-21

Concluding remarks 22

Raschig Super-Ring

Aspects involved in the design of modern packing elements

Packing elements are successfully used in the chemicalindustry and related sectors, as well as in environmentalprotection installations, i.e. in absorption, desorption,extraction and rectification columns. The manifold processengineering demands on modern packing elements aredetermined by these thermal separation processes.

High-performance packing elements are intended to bringabout effective mass transfer between the phases flowingthrough the columns. Large interfacial area and uniformdistribution of the phases over the column cross-section aredesirable. A high loading capacity permits high columnthroughputs, while low pressure drop results in low operatingcosts.

Loading capacity

Counter-current packed columns are preferably operatedbelow, or in the immediate vicinity, of the so-called loadingpoint, this being characterised by the fact that the falling film isbacked up by the counter-current gas stream at higher loads.The loading point of a packing element is defined by its fluiddynamic properties Fluid dynamic studies in the past havedynamic properties. Fluid dynamic studies in the past haverepeatedly shown that the droplets forming in a columnpacking are entrained earlier than down-ward flowing liquidfilms at high gas loads. In contrast to previous packingelement designs, the Raschig Super-Ring meets this demandin that it was purposely designed without any projecting metaltongues which could act as dripping points.

Liquid and gas distribution

The most uniform possible distribution of the liquid and gasphase across the packing element itself and the entire columncross-section is one of the fundamental prerequisites for acolumn packing that works effectively. If, at the same time, alow resistance to fluid flow of the gas phase is to ensure theminimum possible pressure drop, the structure must be largelyp p p, g yopen. The alternating wave structure of the Raschig Super-Ring has not only created a form which is open on all sidesbut, at the same time, has also realised a large number ofcontact points for homogeneous liquid and gas distribution.

1

Raschig Super-Ring

Mass transfer

Effective mass transfer between the phases demands not only alarge interfacial area, but also the most turbulent possible flowconditions and frequent renewal of the phase interfaces. With theRaschig Super-Ring, several thin films of liquid displayingturbulent flow are formed on the sinusoidal webs and areconstantly intermixed as the result of the recurrent contact pointswithin the packing elementwithin the packing element.

Performance data of the Raschig Super-Ring

Experimental studies have confirmed the relationships describedabove. The following Figures show the pressure drop of theRaschig Super-Ring as a function of the gas capacity factor atvarious liquid loads. As a result of a very open structure of theR hi S Ri th d f th d ki iRaschig Super-Ring, the pressure drop of the dry packing isalready lower than that of a 50 mm metal Pall ring. The differencesincreases at higher liquid loads. The Raschig Super-Ringgenerates also a substantially lower pressure drop than otherhigh-performance packing elements made of metal with a nominalsize of 50 mm.

The loading capacity of the Raschig Super-Ring can also beenseen from the following Figures The Raschig Super-Ring not onlyseen from the following Figures. The Raschig Super Ring not onlyhas a higher loading capacity than the 50 mm metal Pall ring, butalso displays a substantially higher loading capacity than previousmodern packing element designs.

The Figures show also the results of trials involving the absorptionof ammonia from air in water. The separation efficiency of this newpacking element is thus up to 14% better than that of a 50 mmmetal Pall ring or previous high-performance metal packingelementselements.

Furthermore, the low specific packing weight of the RaschigSuper-Ring allows the design of low-cost supporting elements inthe columns. The Raschig Super-Ring is also lighter than otherpacking element designs, but without sacrificing stability.Experimental studies have shown that packing heights of 15 mand more can be realised owing to the alternating wave frequencyand amplitude of the metal webs of the Raschig Super-Ring.p g p g

The alternating wave structure additionally prevents entanglementof the packing element within the packing, thus guaranteeingproblem-free assembly and dismantling in a column. Owing to itsopen structure, the Raschig Super-Ring is also suitable for liquidscontaminated with solids. Table 1 shows the technical data of theRaschig Super-Ring.

2

Raschig Super-Ring

The alternating wave structure additionally preventsentanglement of the packing element within the packing,thus guaranteeing problem-free assembly and dismantlingin a column. Owing to its open structure, the RaschigSuper-Ring is also suitable for liquids contaminated withsolids. Table 1 shows the technical data of the RaschigSuper-Ring.p g

Table 1: Technical data of the Raschig Super-Ring's

97250145.000275MetalRaschig Super-Ring No. 0.5



Free Vol.%

Surfacem²/m³

Numberpc./m³

Weightkg/m³

MaterialSize




Free Vol.%

Surfacem²/m³

Numberpc./m³

Weightkg/m³

MaterialSize

981009 500155MetalRaschig Super Ring No 2


9815032.000220MetalRaschig Super-Ring No. 1



981009 500155MetalRaschig Super Ring No 2





961009.00055PlasticRaschig Super-Ring No. 2

9320560.00062PlasticRaschig Super-Ring No. 0.6




961009.00055PlasticRaschig Super-Ring No. 2

9320560.00062PlasticRaschig Super-Ring No. 0.6




97754.00052PlasticRaschig Super-Ring No. 3 97754.00052PlasticRaschig Super-Ring No. 3

3

Raschig Super-Ring

Compensation for the "decrease in volume"

for dumped Packings

The values indicated in the tables for dumped packings are valid for a diameter ratio of the vessel to the packing size of D/d = 20.

Since the arrangement of the packings is less compact near the vessel wall than in the interior of the bed, the number of packings per cubic meter increases with the diameter ratio.

The above diagram shows by which "allowance" the theoretically calculated vessel volume for diameter ratios of more than 20 must be increased in order to completely fill the space required.

If the plastic or metal packings are, for instance, thrown into the column, this may result in a further decrease in volume due to abnormally compact packing.

D = diameter of the vessel to be filled

d = diameter or nominal size of the packings

in die Eckbegrenzungen(Größe 12,6 x 7,8 mm)

kommt ein Foto

4

Pressure drop of metal RASCHIG SUPER-RINGS

system: air/water

RASCHIG SUPER-RING No. 0.3

Column diameter: 0.288 mPacking height: 1 0 m



1000

800900

2000

Liquid load uL in (m3/m2h)uL= 20 10 03040

1000900

2000

Liquid load uL in (m3/m2h) uL= 20 10 03040

Packing height: 1.0 m Packing height: 1.0 m

200

300

400

500

600

700

800

essu

re d

rop p

/H [P

a/m

]

200

300

400

500

600

700

800

essu

re d

rop p

/H [P

a/m

]

100

20

30

40

50

60

70

8090

Spe

cific

pre

100

20

30

40

50

60

70

8090

Spe

cific

pre

1.00.3 0.4 0.5 0.6 0.7 0.8 2.0 3.0 4.0 5.0 6.0

Gas capacity factor FV [Pa1/2]

10

Raschig Super-Ring No. 0.3 made of metal

1.00.3 0.4 0.5 0.6 0.7 0.8 2.0 3.0 4.0 5.0 6.0


10


5


system: air/water



RASCHIG SUPER-RING No. 1

Column diameter: 0.288 mPacking height: 2 0 mPacking height: 2.0 m Packing height: 2.0 m

1000900

2000

Liquid load uL in (m3/m2h)

uL= 20 10 03040

1000900

2000


uL= 20 10 03040

200

300

400

500

600

700

800

essu

re d

rop p

/H [P

a/m

]

200

300

400

500

600

700

800

essu

re d

rop p

/H [P

a/m

]

100

20

30

40

50

60

70

8090

Spe

cific

pre

100

20

30

40

50

60

70

8090

Spe

cific

pre

1.00.3 0.4 0.5 0.6 0.7 0.8 2.0 3.0 4.0 5.0 6.0


10


1.00.3 0.4 0.5 0.6 0.7 0.8 2.0 3.0 4.0 5.0 6.0


10

Raschig Super-Ring No. 1 made of metal

6


system: air/water





1000900

2000


uL= 34.0

22.6

045.3

67.9

113.

2

135.

8

90.5

158.

4

1000900

2000


uL= 20 10 03040

200

300

400

500

600

700

800

essu

re d

rop p

/H [P

a/m

]

200

300

400

500

600

700

800

essu

re d

rop p

/H [P

a/m

]

100

20

30

40

50

60

70

8090

Spe

cific

pre

100

20

30

40

50

60

70

8090

Spe

cific

pre

1.00.3 0.4 0.5 0.6 0.7 0.8 2.0 3.0 4.0 5.0 6.0


10


1.00.3 0.4 0.5 0.6 0.7 0.8 2.0 3.0 4.0 5.0 6.0


10


7

Pressure drop of metal and plastic RASCHIG SUPER-RINGS

system: air/water





1000900

2000


20 10


30406080100

113

uL=

1000900

2000


uL= 20 10 03040

200

300

400

500

600

700

800

essu

re d

rop p

/H [P

a/m

]

0

Raschig Super Ring No. 3 made of metal

200

300

400

500

600

700

800

essu

re d

rop p

/H [P

a/m

]

100

20

30

40

50

60

70

8090

Spe

cific

pre

100

20

30

40

50

60

70

8090

Spe

cific

pre

1.00.3 0.4 0.5 0.6 0.7 0.8 2.0 3.0 4.0 5.0 6.0


101.00.3 0.4 0.5 0.6 0.7 0.8 2.0 3.0 4.0 5.0 6.0


10

Raschig Super-Ring No. 2 made of plastic

8

Transfer efficiency of metal RASCHIG SUPER-RINGS

in the desorption of CO2 from water into an atmospheric air-stream

RASCHIG SUPER-RING No. 0.30.03

0.04

0.025

0.035 Raschig Super-Ring Nr. 0.3 made of metal

Column diameter: 0.288 mPacking height: 1.0 m

0.01

0.02

0.015

L a

Ph [1

/s]

10 20 30 40 505

Liquid load uL [m³/m²h]

0.005

Gas capacity factor Fv = 1.8 Pa0.5

0 04



0.02

0.03

0.04

0.015

0.025

0.035

a Ph [1

/s]

Raschig Super-Ring Nr. 0.5 made of metal

10 20 30 40 505

0.01

0.005

L a



9




0.04

0.025

0.035 Raschig Super-Ring No. 0.7 made of metal


0.01

0.02

0.015

0.025

L a

Ph [1

/s]

10 20 30 40 505


0.005


0 04



0.02

0.03

0.04

0.015

0.025

0.035

a Ph [1

/s]

Raschig Super-Ring Nr. 1 made of metal

10 20 30 40 505

0.01

0.005

L a



10




0.04

0.025

0.035 Raschig Super-Ring No. 1.5 made of metal


0.01

0.02

0.015

L a

Ph [1

/s]

10 20 30 40 505


0.005


0 02


Column diameter: 0.288 mPacking height: 2.0 m0.01

0.02

0.015

a Ph [1

/s]


10 20 30 40 505

0.005

L a



11

Transfer efficiency of metal and plasticRASCHIG SUPER-RINGS



0.02

0.015



0.01

L a

Ph [1

/s]

10 20 30 40 505


0.005


0 02


Column diameter: 0.288 mPacking height: 2.0 m0.01

0.02

0.015

a Ph [1

/s]

Raschig Super-Ring Nr. 2 made of plastic

10 20 30 40 505

0.005

L a



12

Height of a transfer unit HTUOV for metalRASCHIG SUPER-RINGS

for the absorption of NH3 from air in water in the gaseous phase

0.3

0.4



0.2

HT

U o

v [m

] Column diameter: 0.288 mPacking height: 1.0 m

1.00.5 0.6 0.7 0.8 2.0 3.0 4.0 5.0

Gas capacity factor Fv [Pa1/2]

0.1

Liquid load uL = 10 m3/m2h

0 4

0.2

0.3

0.4

U o

v [m

]




1.00.5 0.6 0.7 0.8 2.0 3.0 4.0 5.00.1

HT

U



13



RASCHIG SUPER-RING No.0.70.3

0.4



0.2

HT

U o

v [m

]

1.00.5 0.6 0.7 0.8 2.0 3.0 4.0 5.0


0.1


0 7

0.3

0.4

0.5

0.6

0.7

U o

v [m

]




1.00.5 0.6 0.7 0.8 2.0 3.0 4.0 5.00.1

0.2HT

U



14




0.6

0.7



0.2

0.3

0.4

HT

U o

v [m

]

1.00.5 0.6 0.7 0.8 2.0 3.0 4.0 5.0


0.1


0 7



0.3

0.4

0.5

0.6

0.7

U o

v [m

]


1 00.5 0.6 0.7 0.8 2.0 3.0 4.0 5.00.1

0.2HT

U


1.0


15

Height of a transfer unit HTUHeight of a transfer unit HTUOVfor metal and plastic

RASCHIG SUPER-RINGSfor the absorption of NH3 from air in water in the

gaseous phase

0.6

0.7Raschig Super-Ring No. 3 made of metal


0.3

0.4

0.5

HT

U o

v [m

] Column diameter: 0.288 mPacking height: 2.0 m

1.00.5 0.6 0.7 0.8 2.0 3.0 4.0 5.0


0.2


0 7

0.3

0.4

0.5

0.6

0.7

U o

v [m

]




1.00.5 0.6 0.7 0.8 2.0 3.0 4.0 5.00.1

0.2HT

U



16

Liquid hold-up in columns with metal RASCHIG SUPER-RINGS

system: air/water

0.10

0.20

3]

Liquid load uL in (m3/m2h) uL=

10

203040


0.02

0.03

0.04

0.05

0.060.070.08

uid

hold

-up

hL [m

3/m

10


1.00.5 0.6 0.7 0.8 2.0 3.0 4.0 5.0


0.01

Liqu


0 20

0.10

0.04

0.05

0.060.070.08

0.20

up h

L [m

3/m

3]

Liquid load uL in (m3/m2h)uL= 10203040



1.00.5 0.6 0.7 0.8 2.0 3.0 4.0 5.0

1/2

0.01

0.02

0.03

Liqu

id h

old-

u



17


system: air/water

0.10

0.20

3]

Liquid load uL in (m3/m2h) uL=

10

203040


0.02

0.03

0.04

0.05

0.060.070.08

uid

hold

-up

hL [m

3/m

10


1.00.5 0.6 0.7 0.8 2.0 3.0 4.0 5.0


0.01

Liqu


0 20

0.10

0.04

0.05

0.060.070.08

0.20

up h

L [m

3/m

3]

Liquid load uL in (m3/m2h)uL= 10203040



1.00.5 0.6 0.7 0.8 2.0 3.0 4.0 5.0

1/2

0.01

0.02

0.03

Liqu

id h

old-

u



18


system: air/water

0.10

0.20

3]


uL=

30

40RASCHIG SUPER-RING No. 0.7

0.10

0.02

0.03

0.04

0.05

0.060.070.08

uid

hold

-up

hL [m

3/m

10

20

30


1.00.5 0.6 0.7 0.8 2.0 3.0 4.0 5.0


0.01

Liq


0 20

0.10

0.04

0.05

0.060.070.08

0.20

up h

L in

m3/m

3


uL=

10

20

30

40RASCHIG SUPER-RING No. 1


1.00.5 0.6 0.7 0.8 2.0 3.0 4.0 5.0

1/2

0.01

0.02

0.03

Liqu

id h

old-

u


Gas capacity factor Fv in Pa1/2

19


system: air/water

0.10

0.20

m3


uL= 40


0.02

0.03

0.04

0.05

0.060.070.08

uid

hold

-up

hL in

m3 / L

10

20

30 Column diameter: 0.288 mPacking height: 2.0 m

1.00.5 0.6 0.7 0.8 2.0 3.0 4.0 5.0


0.01

Liq


0 100.10

0.03

0.04

0.05

0.06

0.07

0.08

uo h

L in

m3/m

3


uL=

10

20

30

40



1.00.5 0.6 0.7 0.8 2.0 3.0 4.0 5.0

1/2

0.01

0.02

Liqu

id h

old-

u



20

Liquid hold-up in columns with metal and plastic

RASCHIG SUPER-RINGSsystem: air/water

0.10

0.06

0.07

0.08

m3


uL=RASCHIG SUPER-RING No. 3

0.02

0.03

0.04

0.05

uid

hold

-up

h L in

m3/m L

10

20

30

40


1.00.5 0.6 0.7 0.8 2.0 3.0 4.0 5.0


0.01

Liq


0 20

0.10

0.04

0.05

0.060.070.08

0.20

-up

hL in

m3 /m

3


uL=

20

30

40 RASCHIG SUPER-RING No. 2


1.00.5 0.6 0.7 0.8 2.0 3.0 4.0 5.0

Gas capacity factor F in Pa1/2

0.01

0.02

0.03

Liqu

id h

old-


10


21

Concluding remarks

The Raschig Super-Ring demonstrates that this high-performance packing element meets the numerousdemands of process engineering in an outstandingmanner The above description illustrates that a modernmanner. The above description illustrates that a modernpacking element design today must fulfil a number of fluiddynamic conditions. This is particularly true because, inmost applications, only a fraction of the surface of a fillingmaterial is wetted and used for mass transfer between thephases. However, unused surfaces can easily corrode orgenerate unnecessary pressure drop The Raschig Super-generate unnecessary pressure drop. The Raschig Super-Ring offers decisive advantage in this context, as itssurface utilisation has been optimised in terms of processengineering.

22

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