Chemical resistance of plastics - Lechler...

1

Process Technology

Content / Navigation

n Spray water extinguishing systems

n Vertical cylindrical tank

n Horizontal cylindrical tank

n Spherical tanks

n Summary

n Electronic Documents

n Ordering via Lechler Online Shop

n Contact

1st Edition

Lechler GmbH

Precision Nozzles · Nozzle Systems

P.O. Box 12 23

72544 Metzingen / Germany

Phone: +49 (0 ) 71 23 962-0

E-Mail: [email protected]

Cooling and fire extinguishing systemsfor tanks

2

Content

n Spray water extinguishing systems 3Overview 3Spray nozzle system design for different shapes of storage tanks 3

n Vertical cylindrical tank 4Total flow rate vertical cylindrical tank 5Nozzle quantity 6Nozzles for vertical cylindrical tanks – surface shell spray 7Nozzles for vertical cylindrical tanks – roof spray 9

n Horizontal cylindrical tank (conventional installation) 11Optimization horizontal CO2 tank from figure 12 12Solution: Installation of a bigger pipe for the horizontal CO2 tank from figure 12 12Example: horizontal tank (best practise design example) 13Conclusion 13Nozzle selection for horizontal tanks 14

n Spherical tanks 15

n Summary 16Nozzle selection - for all tank shapes 16

n Electronic Documents 17

n Ordering via Lechler Online Shop 17

n Contact 18

2Cooling and fire extinguishing systems for tanks

Index | Content

3

n Spray water extinguishing systems

Overview

Spray irrigation of tanks aims to protect tanks and

other vessels against unacceptable heating during

burning. Here, heating must be understood as a

condition where an increase of a tank’s inner pres-

sure and a decrease of the tank walls’ resistance,

will lead to bursting of the tank. Also important is

the heat-influenced breakdown of the sealing ele-

ments in detachable connections.

Water spray simultaneously extinguishes and

cools the complete surface of the incendiary mat-

ter. If a fire occurs in a chemical plant, a water-spray extinguishing system will be activated over the

entire system heated by the fire. This produces steam, which aids the cooling and fights the fire.

Spray nozzle system design for different shapes of storage tanks

This document assists in finding a proper nozzle system design for different shapes of storage tanks. It

offers also some ideas for special tank shapes. We picked the nozzle series from our broad assortment

which are suited best in our opinion for each different shape.


Index | Content

Illustration 1:Where flammable liquids are stored, one must take special measures protecting against fires

4

n Vertical cylindrical tank

Tank up to a height of 12 m: 1 circular pipeline

Tank with a height of more than 12 m: 2 to 3 circular pipelines

For a tank with a diameter greater than 20 meters,

the circular pipeline can be divided into a maxi-

mum of three cooling sectors; this ensures that

the feeding pipes will not be too large. The water

supply is consecutively connected to the sectors

in case of cooling. The nozzle rings must be fixed

below the tear seam. If necessary for a fixed roof

tank, roof sprinkling can be performed for fire pro-

tection - although this may not be absolutely ne-

cessary, according to DIN 14495. The nozzles for

roof sprinkling of the roof may be installed to spray

towards the top or bottom. The rising pipeline for

roof sprinkling must be engineered with a separa-

tely shut-off.

Suitable nozzles from our main catalogue: Flat-jet and tongue type >> Click here <<


Index | Content

1

3

4

2

Illustration 2: Nozzle positions for a vertical cylindrical

tank with a height < 12 m

1) Feeding pipes

2) Sprinkling of the roof

3) Tear seam

4) Circular pipeline

30°

200 – 300 mm

1000

– 1

500

mm

Tear seam

Illustration 3: Installation of the circular pipeline with

flat- jet nozzles

200 – 300 mm

1000

– 1

500

mm

Tear seam

75°

Illustration 4: Installation of the circular pipeline with

tongue type nozzles

Full cone nozzles

Flat-jetortongue typenozzles

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5

Total flow rate vertical cylindrical tank

The total flow rate is calculated using the genera-

ted surface of the cylinder and the sprinkling flow

density (Illustration 5).


Index | Content

Tank diameter

0

20

20

40

40

60

60Sp

rinkl

ing

flow

den

sity

80

80 m

100

100

l/m /h2

Illustration 5: The sprinkling flow density of the tank di-

ameter can be determined according to German norm

DIN 14495. If there are dangerous goods deposited,

the sprinkling flow density must be doubled.

&

&

V M Sprinkling flowdensity

V D h Sprinkli

total

total

= ⋅

= ⋅ ⋅ ⋅

( )

( nng flowdensity

with h

D

)

tank height

tank diam

== eeter

surface shell

Example: tank with D = 10 m,

M =

h = 10 m:

&

&

V m ml

m h

Vl

h

total

total

= ⋅ ⋅ ⋅⋅

= =

10 10 60

18849 6 314

2

, ,116l

min

6

Nozzle quantity

The quantity of nozzles needed is determined bythe circumference (C) of the circular pipeline, divi-ded by the nozzle distance (A = distance fromnozzle to nozzle)

The nozzle distance for the Lechler flat jet nozzleis:

A = 1.2 m up to 1.5 m

and for the Lechler tongue type nozzle:

A = 1.7 m up to 2.0 m

The nozzle type can be selected using the calcu-lated flow rate. The nozzles can be fixed accor-ding to Illustration 3, 4 and 6 at the circular pipeli-ne.

Now, the flow rate for each nozzle can be calculated:


Index | Content

300

1200

– 1

500

mm

for f

lat f

an n

ozzl

es17

00 –

200

0 m

m fo

r ton

gue

nozz

les

A

Illustration 6: Circular pipeline around a vertical cylin-

drical tank with flat jet or tongue type nozzles

Nozzle quantity = = ⋅C

A

D

A

&&

VV

nozzlequantitynozzle

total=

Example with flat-jet nozzlees

Nozzle quantity

&Vl

C

A

D

A

total =

= = ⋅

314 16,min

= ⋅ =

= =

10

1 226

314 16

2612 08

m

m

V

ll

nozzle

,

,min ,

min&

7

Nozzles for vertical cylindrical tanks – surface shell spray

Flat-jet nozzles series 616/617

Flow-rate table

You can download our entire flat jet nozzle program directly as pdf-file if you have an active connectionto the internet:

§ Lechler main catalogue flat-jet and tongue type nozzles >> Click here <<

§ Overview accessories for nozzle installation >> Click here <<


Index | Content

Figure. 7: Lechler flat-jet nozzles series 616/617

Type Material-No.

1.43

05

AØ

[mm]

EØ

[mm]

V [l/min]

17 3016

1.45

71

<).

p [bar]

Bras

s

H

B

0,5 1,0 2,0 3,0 5,0 7,0 10,0H =

250 mmH =

500 mm

120° 3,003,504,005,005,506,008,00

1,601,702,002,602,903,204,40

3,154,005,008,00

10,0012,5020,00

4,455,667,07

11,3114,1417,6828,28

6,308,00

10,0016,0020,0025,0040,00

7,729,80

12,2519,6024,4930,6248,99

9,9612,6515,8125,3031,6239,5363,25

11,7914,9718,7129,9337,4246,7774,83

14,0917,8922,3635,7844,7255,9089,44

975970965955950950950

1755175017401730172017201720

--

--

616. 727616. 767616. 807616. 887616. 927616. 967617. 047

Spr

ay a

ngle

Ordering no. S pray widthB

at p = 2 bar

A = Equivalent bore diameter · E = narrowest free cross section*Differing spray pattern. S ubject to technical modifications.

Convers ion formula for the above series : V2 = V1 *p2p1

. .






Index | Content

Tongue type nozzles Series 686/687

Flow-rate table

You can download our entire tongue type nozzle program directly as pdf-file if you have an active con-nection to the internet:

§ Lechler main catalogue flat-jet and tongue type nozzles >> Click here <<


G

B

Figure. 8: Lechler tongue type nozzles 686/687

Type Material-No. Code

1.43

05

BØ

[mm]

V [l/min] Dimensions

3016

PVD

F

5E

Bras

s

EN 1

0226

R 1

/8

EN 1

0226

R 1

/4

<) η

p [bar]

.

H

B

L HEX H =[mm] [mm] 250

1,0 2,0 5,0 R 1/8 R 1/4 R 3/8 R 1/2 R 1/8 R 1/4 R 3/8 R 1/2 mm

B = bore diameter Also suitable for superheated steam and saturated steam

EN 1

0226

R 3

/8

EN 1

0226

R 1

/2

140°

-

-

CACA-

CACACACA-

CA-

CA--------

--

CCCCCC-

CCCCCCCCCCCCCCCCCCCC---

686. 368686. 408686. 448686. 488686. 528686. 568686. 608686. 648686. 688686. 768686. 808686. 828686. 848686. 868686. 888686. 908686. 928686. 968686. 988

75° -----

-------------

0,801,001,201,301,501,701,902,202,403,003,403,603,804,004,204,504,705,305,60

-----------------

CGCG

---

------------

CECECE

0,450,710,881,131,411,772,232,833,545,667,077,928,809,90

11,3112,7314,1417,6819,80

0,631,001,251,602,002,503,154,005,008,00

10,0011,2012,5014,0016,0018,0020,0025,0028,00

1,001,581,982,533,163,594,986,327,91

12,6515,8117,7119,7622,1425,3028,4631,6239,5344,27

2323-

23232323-

23-

23--------

--

282828-

28282828282828282828---

----------------

323232

-----------------

4040

1111-

11111111-

11-

11--------

--

141414-

14141414141414141414---

----------------

171717

-----------------

2222

1360137013701370137013701370137013701370137013701370137013701370137013701370

-

Spr

ay a

ngle

Ordering no.S pray width

Bat p = 2 bar

Weight brass: 18 g






Index | Content

Nozzles for vertical cylindrical tanks – roof spray

Full cone nozzlesSeries 460

Flow-rate table

You can download our entire full cone nozzle program directly as pdf-file if you have an active connec-tion to the internet:

§ Lechler main catalogue full cone nozzles >> Click here <<


Type Material-No. Code

1.45

71

BØ

[mm]

EØ

[mm]

V [l/min]

3017

Bras

s

5E

PVD

F

EN 1

022 6

R 1

/ 8

EN 1

0226

R 1

/ 4

EN 1

0226

R 3

/ 8

EN 1

0226

R 1

/ 2

G 3

/ 4A

ISO

228

G 1

A

ISO

228

<)

p [bar]

.

H

B

H = H =200 500

0,5 1,0 2,0 3,0 5,0 7,0 10,0 mm mm

D

*-

---

---

C EC E

-

-C GC G

---

---

4,204,605,30

2,703,103,30

7,189,19

11,49

9,4712,1315,16

12,5016,0020,00

14,7018,8223,52

18,0323,0828,85

20,6326,4133,01

23,8030,4638,07

680680680

133013301330

460. 848460. 888460. 928

120°

* Available with Code CG only

Spr

ay a

ngle


at p = 2 bar

B = bore diameter · E = narrowest free cross section

C onvers ion formula for the above series : V2 = V1 *p2p1

. .

Figure 9: Lechler full cone nozzles series 460 (axial flow design)







Index | Content

Full cone nozzlesSeries 422

Flow-rate table




120°

Type Mat.-No. Code

BØ

[mm]

EØ

[mm]

V [l/min]

30

Bras

s

17

1.45

71

EN 1

0226

R 1

/ 4

EN 1

0226

R 3

/ 8

EN 1

0226

R 1

/ 2

<)

p [bar]

.

H

B

H = H =200 500

0,5 1,0 2,0 3,0 5,0 7,0 10,0 mm mm

D

422. 848422. 888422. 928 -

---

C EC E

-

--

C G

5,205,807,30

5,105,707,30

6,258,00

10,00

8,8411,3114,14

12,5016,0020,00

15,3119,6024,49

19,7625,3031,62

23,3929,9337,42

680680680

160016001600

27,9535,7844,72

B = bore diameter · E = narrowest free cross section

C onvers ion formula for the above series : V2 = V1 *p2p1

. .

Spr

ay a

ngle


at p = 2 bar

Figure 10: Lechler full cone nozzles series 422 (tangential flow design)





11

n Horizontal cylindrical tank (conventional installation)

Basically we show 2 different designs for pipe and nozzle installation. The first one below is basic and

offers not enough cooling during a big fire. On page 13 you can find an optimized installation which can

sustain bigger fires and higher heat convection rates.

Depending on the nozzle size and spray angle, distance A should be between 0,7 m and 1.2 m

Distance H, to the material of the tank, should be between 0,3 m and 0,4 m

Distance B, to the vertical parts of the tank should be between 0,4 m and 0,5 m

The sprinkling rate should not be less than 400 l/(m2h). Usually it is bet-

ween 400 and 600 l/(m2h). For installations with higher risk potential

the sprinkling rate can be increased up to 1000 l/(m2h).

Spray angle of the spray nozzles: > 90°

Figure 12 shows a tank for CO2 storage.The spray system shall be enhanced. In

this special case it is not possible tochange the pipes. Read on the

following page about possi-ble solutions for this

case.


Index | Content

L

A

H

B

A

D

Figure 11: Two pipes are necessary for sprinkling along the tank shell. The vertical parts of the tank can be spray-

ed with one nozzle up to a diameter of 3 m, and require three Lechler full cone nozzles for larger diameters.

Figure 12: Arrangement of full cone nozzles series 468.846.30 over a gas tank. For installation plastic clamps we-

re used.

12

Optimization horizontal CO2 tank from figure 12

§ Available pump capacity: 162 l/min at 5 bar

§ Pipe diameter: 3/4”

§ Currently there are 6 nozzles of series 468.846.30. installed

With the current installation it is not possible to reach the desired flow rate of 162 l/min at 5 bar since

the nozzles are too small and increasing the pressure would exceed the available limit of the pump.

There are 4 possible solutions:

1. Installation of another 3 nozzles in order to reach 162 l/min

2. Increase of the pressure, and therefore a different pump

3. Installation of a larger full cone nozzles. This would also mean to change the clamps of the

nozzles

4. Installation of a different (bigger) pipe.

Option 2 is the least favorable since a new pump is expensive. Option 1 and 3 are possible but the pi-

pe diameter is too small, so a higher pressure loss would lead to a smaller flow rate than intended.

Option 4 is most suitable and probably the best to describe here since it shows how to make it right in

the first place.

The following documents are needed for the design:

Documents for design: § Lechler main catalogue full cone nozzles >> Click here <<


Solution: Installation of a bigger pipe for the horizontal CO2 tank from figure 12

§ Length of the tank L = 4,5 m

§ Tank diameter d = 1,7 m

§ Sprinkling flow density 400 l/m2/h

Calculation for the required total flow rate:

Depending upon requirement a new pipe network

has to be designed and afterwards the nozzle po-

sitions must be chosen. In order to achieve a good

water distribution with less nozzles the spray angle

should be > 90°. The total flow rate of all nozzles should not fall below 160 l/min as calculated above.

Have a look on the next page for a best practice example of a pipe and nozzle installation around a ho-

rizontal tank.


Index | Content

&

&

V M Sprinkling flowdensity

V d L Sprinkling flow

ges

ges

= ⋅

= ⋅ ⋅ ⋅

, , , ,min

density

V m ml

m h

l

h

lges& = ⋅ ⋅ ⋅

⋅= =1 7 4 5 400 9613 27 160 22

2

witth Length of the tank

Tank diameter

L

d

==



13

Example: horizontal tank (best practice design example)

The installation below was designed by tank experts and approved during fire tests. Although this is a very

large installation is was effective. Especially the lower surface of the tank is now sprayed with a higher

amount of water since it is heated comparatively fast when exposed to fire. Therefore larger spray nozz-

les are applied for particularly intensive cooling. Furthermore, it was found out that running water on the

tank wall is not very effective against fire. Now, the complete surface of the tank wall is hit directly by a

spray nozzle and the jets of the spray nozzles are overlapping.

In order to minimize the risk of spray nozzle clogging a filter should be used. Using tangential type full

cone nozzles lowers the risk of clogging additionally since the narrowest cross section of these nozzles

is larger in comparison to the axial types.

Conclusion

In case of a fire it is important to cool the tank surface on all sides with full cone nozzles.

Installing only nozzles above the tank leaves the most critical area (the lower part) unprotected.

Running water on the tank shell is not effective enough. During fire test an average sprinkling

rate of approximately 400 l/(m2h) was set as limit. Lower rates are critical.


Index | Content

Figure 13: Improved nozzle and pipe arrangement around a horizontal cylindrical tank. For cooling axial and tan-

gential full cone nozzles are used

A Axial type full cone nozzles

T Tangential-full cone nozzles

Water amount:

400 to 600 l/m2 h shell surface

480 to 1000 l/m2 h lower tank surface


Index | Content

Nozzle selection for horizontal tanks

Generally full cone nozzles should be used. Thecorrect nozzle must be determined individual foreach case. However, Lechler has numerous diffe-rent nozzle types and mounting options in theavailable, in order to make a suitable solution foryou as easy as possible.

Recommended approach for nozzle selection:

§ First of all calculate the required total flow

rate. Use the formula on page 12.

§ Open the chapter full cone nozzle in Lechler’s

main catalogue or click here.

§ Look only for nozzles with a spray angle

bigger than > 90°

§ Depending on your tank dimensions

determine how many nozzles you need and

how you install them around the tank. Have a look at pages 11 to 13 for examples.

§ Divide the total flow rate by the number of nozzles

§ With the flow rate per nozzle you can further narrow your search in the catalog

§ Select a suitable assembly option for your nozzle - see chapter accessories in the catalogue




Figure 14: Lechler full cone nozzle series 460.368.

spraying at a pressure of 5 bar. The spray angle is

120° (at 2 bar)





15

n Spherical tanks

Spherical tanks must be sprinkled on all sides, in-

cluding the supporting structure. According to EN

1363, the fire-resistant sustainers are excluded. In

the Lechler Firefighting Nozzles brochure, tangen-

tial hollow cone nozzles are suggested; however,

tests using horizontal cylindrical tanks suggest full

cone nozzles should be used here (at least for the

lower part of the tank.) The lower spherical section

of the tank must be sprayed with a higher flow rate

than the upper section of the tank. A full cone nozz-

le, directed on the south pole of the spherical tank,

will offer additional protection.

Nozzle gap (radian measure A):

A = 1,5 m to A = 2,5 m

Nozzle distance from tank wall (H):

H = 0,3 m to 0,5 m

For sprinkling of the shell three nozzle ring pipes

have to be installed in regular distances for tank

diameters up to 18 m. Spherical tanks with more

than 18 m diameter have to be equipped with 4

nozzle ring pipes or more.

Nozzle selection

Lechler recommends nozzles of series 422 which

have a tangential water supply. In connection with

a filter unit this offers additional protection against

clogging. The material of the nozzles should be

brass or stainless steel.

§ Lechler main catalogue full cone nozzles

>> Click here <<

§ Overview accessories for nozzle installation

>> Click here <<


Index | Content

Figure 15: Spherical tank with water spray cooling (3

ring pipes)

H

22,5°

22,5

°

45°

A

Figure 16: Nozzles installation around a spherical tank





Index | Content

n Summary

For effective tank protection, it is imperative that the complete tank is sprayed with water from all

sides. Tests have shown that full cone nozzles provide a better cooling result than hollow cone

nozzles.

Other fixtures, including flanges and armatures must be sprayed specifically and directly, sin-

ce a trickling film is insufficient. Under the effects of heat, soot and peeling container color, a trickling

film is frequently interrupted and therefore loses its cooling efficiency.

The total flow rate of 400 l/(m2h) which was evaluated during fire tests should be met for horizontal

cylindrical tanks. For other tank shapes the formula of figure 5 is valid (see page 5).

The water must be filtered in a manner adjusted to the nozzles smallest cross section. The value of

the smallest cross section is specified in the main catalogue of Lechler for each nozzle. The sprink-

ling/cooling system should undergo periodical maintenance tests (a performance test) in order to be

on the safe side.

An adequate supply of freeze-resistant water must be readily available so the sprinkling can begin in

case of fire during the winter months.

Nozzle selection - for all tank shapes

The table below shows the suitable nozzles types for different tank shapes. In case you read this pdf

on a PC with working internet connection you can download the corresponding datasheets with one

click.

Tank shape Vertical

cylindr. tank

Horizontal

cylindr. tank

Spherical

tank

Recommended

spray angleDatasheet

Nozzle series/type

Flat-jet nozzles

e.g. Series 616ü – – 120° Download

Tongue-type

e.g. Series 686/687ü – – 140° Download

Full cone nozzlese.g. Series 422/460/468 ü ü ü 120° Download


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Index | Content

n Electronic Documents

In case you have an active internet connection you can download related documents directly out of this

PDF. When you have no internet connection you can request a paper version of the documents.

Lechler Strainers >> Download <<

Lechler Nozzle Accessories >> Download <<

Nozzle Assembling Options >> Download <<

Conversion Tables and Working Aids >> Download <<

Lechler Main Catalogue >> Download <<

n Ordering via Lechler Online Shop

Browse to https://shop.lechler.de and find even more documents about nozzles and atomization tech-

nology. Get yourself registered and buy nozzles online. In adition registered users have access to dedi-

cated papers.

To get registered for the Lechler Online Shop please write an eMail to: [email protected]

We would be pleased to welcome you at our Shop.

Yours sincerely

Lechler Competence Center for Atomization Technologies

mailto:[email protected]

https://shop.lechler.de

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Index | Content

Lechler GmbH

Precision Nozzles · Nozzle Systems

P.O. Box 12 23

72544 Metzingen / Germany

Phone: +49 (0 ) 71 23 962-0

E-Mail: [email protected]

©Lechler GmbH 2010

n Contact

In case you need further assistance when selecting nozzles for your application, contact us directly.

You can reach us by phone or via eMail.

Lechler GmbH

Ulmer Str. 128

72555 Metzingen, Germany

Phone: +49-7123-962-0

Fax: +49-7123-962-444

eMail: [email protected]

Lechler Inc.

445 Kautz Rd.,

St. Charles, IL 60174 USA

Phone: +1-(800)-777-2926

Fax: +1-(800)-444-7069

eMail: [email protected]

Lechler India Pvt. Ltd.

Plot No B 2, Main Road, Wagle Industrial Area,

THANE 400 604, India

Phone: +91-22-2582-1196

Fax: +91-22-2582-1262



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