SHELL AND TUBE HEAT EXCHANGERS

INTRODUCTION

Shell & tube heat exchangers offer large surface area in combination with efficient heat transfer and compactness. These are widely used in industries for various duties like cooling, heating, condensation, evaporation etc. GOEL are the pioneers in the field of glass shell and tube heat exchangers in India and their product has wide market acceptability.

SALIENT FEATURES

  1. Universal corrosion resistance an excellent alternative to expensive MOCs like graphite, hastelloy, copper titanium, tantalum and other exotic metals.
  2. Excellent heat transfer as fouling does not occur on smooth glass surfaces.
  3. Flexibility of installation vertical / horizontal.
  4. Easy replacement of tubes for repair and cleaning.
  5. Available in wide range of HTAs.
  6. Ease of installation due to light weight.
  7. Economical.
  8. Suitable for applications where large HTAs are required in limited space.

 

ADVANTAGES OVER CONVENTIONAL COIL TYPE HEAT EXCHANGERS

  1. The overall heat transfer coefficient in shell and tube heat exchanger is about 3 times higher than in coil type heat exchanger.
  2. The pressure drop in shell and tube heat exchanger is minimal compared to 2-3 kg/cm² in coil side of coil type heat exchanger.
  3. For requirement of higher heat transfer areas shell and tube heat exchanger is the only alternative.

 

CONSTRUCTION FEATURES

The glass tubes are sealed individually into PTFE tube sheet with special PTFE sockets and packing. This unique ferrule type sealing arrangement permits easy replacement and cleaning of tubes. Baffles on shell side ensure improved heat transfer by increased turbulence. Further details of construction can be seen in the diagram.


TYPE

Three basic versions * are available :

Material of construction

Model

Shell

Tube

Header

Duty

RGG

Glass

Glass

Glass

For heat transfer between two aggressive media.

RGM

Glass

Glass

Steel/FRP

For heat transfer between aggressive media in shell & non-aggressive media in tubes.

RMG

Steel/FRP

Glass

Glass

For heat transfer between aggressive media in tubes & non-aggressive media in shell.

* GOEL provides assistance to clients for selecting the right model for specific duty.

DIMENSIONAL SPECIFICATIONS

Cat. Ref.
RGG/RMG

6/3

6/4

6/5

6/6

9/6

9/8

9/10

9/12

12/12

12/16

12/21

12/25

Area (m²)

3

4

5

6

6

8

10

12

12

16

21

25

DN

150

225

300

DN1

80

100

150

DN2

50

80

80

DN3

25

40

40

DN4

50

50

50

H1

175

250

300

H2

150

200

250

L

2500

3100

3700

4300

2620

3220

3820

4520

2550

3150

3950

4550

L1

1900

2500

3100

3700

1900

2500

3100

3800

1800

2400

3200

3800

L2

150

150

150

150

225

225

225

225

225

225

225

225

L3

1600

2200

2800

3400

1450

2050

2650

3350

1350

1950

2750

3350

L4

250

250

250

250

300

300

300

300

300

300

300

300

L5

125

125

125

125

175

175

175

175

175

175

175

175

L6

1980

2580

3180

3780

2000

2600

3200

3900

1930

2530

3330

3930

T

50

60

75

No. of Tubes

37

73

151

No. of Baffles

11

15

19

23

7

9

13

17

5

7

9

11

Nozzles in metal shell are drilled as per Table F

RANGE OF APPLICATIONS

Permissible temperature range for both shell & tube sides -140°C to 150°C
Maximum permissible temperature difference between shell & tube sides 120°C

All sizes & models are suitable for full vacuum on both sides. Maximum limiting pressures are tabulated here below

Model

Side

Maximum Permissible Pressure Range, Kg/cm² (g)

150DN

225DN

300DN

RGG

Shell
Tube

2.0
2.0

1.0
1.0

1.0
1.0

RGM

Shell
Tube

2.0
3.5

1.0
3.5

1.0
3.5

RMG

Shell
Tube

3.5
2.0

3.5
1.0

3.5
1.0

The above ranges of application are admissible limiting values. For each specific case GOEL recommends the admissible operating data based on the relations between pressure and temperature, size and model.

PERFORMANCE & DESIGN DATA

The particular advantage of shell & tube heat exchanger is high heat transfer performance. The relation between heat transfer and velocity of flow can be easily seen in the diagram. On receipt of the operating data from client the most favorable shell and tube heat exchanger is selected. This accurate design combined with most reliable quality assurance ensures economy and operational reliability for the user. For approximate sizing some typical heat transfer coefficients are given here below :

Media

Use

U-Values

Kcal/m² hr k

W/m² k

Steam-water

Condensation

350 - 550

410 - 640

Water-water

Cooling

250 - 350

290 - 410

Water-air

Cooling

30 - 60

35 - 70

Following accessories are recommended to use with Shell and tube heat exchanger :

- PTFE bellows on all nozzles.
- Pressure relief valve.
- Supporting clamps.