LOW PRESSURE VESSELS



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INTRODUCTION

The benefits of continually over feeding the evaporators of a multi-circuited refrigeration system are popular world over amongst industrial users of ammonia refrigerant. Pumped liquid ammonia is the preferred method of evaporator feed because of its simplicity and high performance. By completely wetting the inner surface of evaporator coils with an excessive flow of subcooled liquid refrigerant maximum heat transfer rates are achieved, resulting in higher system efficiency and reduced operating cost.

TECHNICAL DETAILS

Table for Low Pressure Receiver Selection :

Capacity : Tons of Refrigeration
 

Vessel Dia
Inches

Vessel Length
Feet

Evaporation Temperature (F)

   

Based on two stage compressors

Based on single stage compressors

   

(-) 50

(-) 40

(-) 30

(-) 20

(-) 10

0

(-) 10

20

30

40

50

20

10

10

12

14

17

19

21

23

26

28

30

32

24

10

24

28

34

40

44

49

54

60

66

72

78

30

10

57

70

85

101

111

123

135

146

162

175

188

36

10

109

130

156

183

203

223

246

272

302

331

360

42

10

175

209

251

295

327

360

397

436

488

534

580

48

12

254

304

365

429

475

526

580

640

713

776

839

54

12

328

396

477

561

622

687

756

837

928

1022

1117

60

12

416

498

601

710

790

871

963

1070

1181

1294

1404

The data given in the table is just indicative for details please Contact Us

Metalex Re-circulation systems follow th Witt (Germany) designs to ensure trouble free, no turbulence flow of liquid to the evaporators through refrigerant pumps and also prevents the liquid getting sucked to the compressor thus protecting the compressors of liquid hammer.
 

  • Each LP receiver is supplied with Metalex make high pressure reflex type gauge glass, high and low side liquid floats, Isolation Valves, Duel Safety Valve, Drain Valve and Purge Valve. The receiver is mounted on a sturdy steel structure.
  • Inter connecting piping on the skid.
  • Working Pressure 6 Kg / CM2.
  • Test Pressure 21 Kg / CM2.

SPECIFICATIONS

• Increase in Efficiency: Our system ensures The internal surface of cooling coils (evaporator) is completely wetted and therefore provides much better efficiency of the refrigeration system with Laminar flow.
• Less Down leg Required: Overall height of LPR is low compared with others, Lower plant room height saves amount in civil costing.
• Protection to compressor: The compressor is protected from liquid slugs resulting from fluctuation system load or controls manufacturing of multiple units.
• Lower Discharge pressure: Low suction superheat is achieved where the suction line between the LPR and compressor is short. This cause a minimum discharge Temperature, Preventing lubrication Breakdown and minimum condenser fouling.
• No Need of Accumulators: There is no need of Individual accumulator for every ammonia air cooling unit because one large accumulator ( surge drum ) of liquid circulation system.
• Simple control Adjustment: Refrigerant feed to evaporators is unaffected by fluctuating ambient and condensing condition. The flow control regulators do not need to be adjusted after the initial setting because overfeed rates are not critical.
• No Extra Pressure Drop: Flash gas regulating from refrigerant throttling losses is removed at the low pressure receiver before entering the evaporators. This gas is drawn directly to the compressor and eliminated as a factor in the design of the system low side. It does not contribute to increased pressure drops in the evaporators or overfeed lines
• Increase in compressor life: Because of ideal entering suction gas conditions, compressors last longer and there is less maintenance and fewer breakdowns. The oil circulation rate to the evaporators is reduced as a result of the low compressor discharge superheat and separation at the ( surge drum- accumulator ) Low pressure receiver.
• Easy & Simple Control of System: Refrigerant level controls, level indicators, refrigerant pumps, and oil drain are generally located in the [plant rooms which are under operator surveillance or computer monitoring. Ammonia liquid recirculation systems are more convenient for automatic operation and easy to maintain

• Overall benefit: Liquid recirculation systems are most useful for multiple number of cooling units as well as having multi temperature cold room of freezers.

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