Types: 0312, 0412, 0515, 0615, 0820, 0920, 1020, 1220, 1420, 1620
VMA intermediate cooler
Installation, operation and maintenance manualen
VMA intermediate cooler
Design
The intermediate cooler consists of a shell with a dished end cover welded on to each end.
Various nozzles are welded in the shell and dished end covers as well as inlet and outlet
from/to the coolers and compressor. All nozzles are welding connections.
Product description
VMA - general information
The VMA cooler is a closed flash intermediate cooler with a built-in subcooling coil.
VMA is used in two-stage refrigeration plants to cool down the discharge gas and for subcool-
ing of the liquid from the condenser.
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The VMA cooler is designed for:
• Low pressure drop on the gas side
• Excellent part load performance
• No liquid carry-over
• Low superheating of the suction gas
• Liquid subcooling to about 5 K higher temperature than the intermediate temperature
• Easy installation and insulation
Function
A float valve controls the supply of liquid refrigerant to the cooler and maintains a constant
liquid level during operation. Flash gas leaves with the suction gas to the high-stage compres-
sor.
The low-pressure discharge line enters through the top, and the gas is cooled by bubbling up
through the liquid. The cold gas leaves through the top as suction gas for the high-stage com-
pressor. The liquid from the condenser passes the intermediate cooler through a submerged
coil and leaves as subcooled liquid for the evaporators.
Construction
VMA is manufactured from heavy gauge steel plates with domed ends. The cooler is delivered
with:
• Oil drain valve
• Connections for float valve and stop valves
• Connection for liquid injection from VMA-type 1020
• Gas inlet connection from LP compressor
• Gas outlet to HP compressor
• Liquid inlet and outlet
Options
• Low-pressure float valve and stop valves
• Connections for maximum level control
• Insulation
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Type Nominal capacity Qnom 1)
VMA kW m3/h
0312 48 66
0412 85 116
0515 160 219
0615 230 315
0820 430 588
0920 540 739
1020 680 930
1220 980 1340
1420 1350 1847
1620 1760 2407
Table 1: Capacities
1) Corresponding to the high-stage compressor capacity/swept volume at -10°C intermediate
temperature: R717.
Correction factor for other intermediate
temperatures (Qnom = Qoh/f):
0.7
0.8
0.9
1.0
1.1
1.2
1.3
-22 -20 -18 -16 -14 -12 -10 -8 -6 -4 -2 0
Correction factor f
Intermediate temperature (tm °C)
Example:
LP screw compressor:
Qo = 256 kW at -50/-15°C
No = 74 kW
Oil heat rejection = 39 kW
HP compressor selection:
Qoh = 256 + 74 - 39 = 291 kW
VMA-type:
Qnom = Qoh/f = 291/0.875 = 332 kW
Selection: VMA 820
Type Volume Refrigerant øD Ls HH
max.
WT
max.
Weight
1)
Weight
2)
VMA Liter Coil Shell mm mm mm mm kg(net) kg(net)
0312 100 4 25 324 1250 1940 985 110 133
0412 162 5 55 406 1250 1985 1090 180 203
0515 271 7 115 508 1480 2295 1195 320 343
0615 485 8 190 610 1480 2360 1305 410 433
0820 1105 24 435 800 1980 2985 1510 730 756
0920 1428 26 595 900 1980 3035 1650 830 856
1020 1781 30 870 1000 1980 3095 1745 1180 1205
1220 2675 48 1110 1200 1980 3220 1965 1690 1715
1420 3766 56 1735 1400 1980 3325 2165 1950 1975
1620 5047 68 2330 1600 1980 3425 2365 2620 2635
Table 2: Volume, weights and main dimension
1) excluding liquid level control
2) including liquid level control
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2
3
1
9
5
8
8
7
6
LS
HH
1/2” RG
500 100
E
J
G
4
5
3
WT
WT
B
A
A
C
A4
5
3
A
B
C
10
10
Pos. 8: For max. level control, DN25.
Pos. 9: For safety valve, DN25.
Pos.10: Oil Drain.
VMA-
type
Pos.
1
Pos.
2
Pos.
3
Pos.
4
Pos.
5
Pos.
6
Pos.
7A B C E J G
Vapour
outlet
Vapour
inlet
Liquid
outlet
Liquid
inlet
Level
upper
Level
lower
Liquid
inject.
DN DN DN DN DN DN DN mm mm mm mm mm mm
0312 40 40 15 15 32 25 - 200 95 170 295 500 1050
0412 50 50 15 15 32 25 - 260 120 250 325 50 1060
0515 80 80 20 20 32 25 - 33 140 300 395 580 1230
0615 80 80 20 20 40 32 - 405 175 360 380 600 1275
0820 100 100 25 25 50 40 - 545 245 440 470 815 1640
0920 125 125 25 25 50 40 - 600 270 520 675 880 1835
1020 150 150 32 32 25 25 32 670 280 580 750 1135 2385
1220 150 150 40 40 25 25 32 815 340 860 770 935 2335
1420 200 200 50 50 25 25 32 960 420 1050 850 875 2415
1620 250 250 50 50 25 25 32 1100 475 1200 890 930 2455
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Shipping
The vessel must be blanked off and primed on delivery. The primer is not intended for out-
door storage. If the vessel is not put into immediate service, take precautions against corro-
sion or contamination.
Only lift the vessel when it is empty, and make sure it is not subjected to strokes or bumps
during transport. When lifting the vessel before it is built into the unit, always use straps
around the shell.
The weight is stated in the technical data.
A shipping description can be made when the vessel is built together with the unit.
Installation
The site and personal protection must be in accordance with EN 378-3 or national require-
ments.
Check the vessel immediately upon receipt for any damage occurred during transport. If the
vessel is damaged, it must not be installed and started.
When placing the vessel, make sure there is enough space for inspection, maintenance, es-
cape and emergency.
Foundations must be sufficiently robust, as their purpose is to provide permanent support
without settling and to absorb any normal vibrations from outside causes.
The vessel is for vertical installation.
Blanked off branches must be cut off at the cutting groove depending on metal thickness on
adjoining tubes. Make sure that no dirt or other unknown elements enter the vessel during in-
stallation.
Do not remove protective plugs and covers until immediately before installation.
The entire system must be clean before starting the operation. When fitting the tube connec-
tions, make sure that stress in the vessel during test, operation and standstill does not ex-
ceed the allowable values. Vibrations must be minimised, possibly by means of vibration
dampers.
Apart from branch connections, welding must not be carried out on the vessel.
The vessel must be secured against exceeding the allowable pressures and temperatures.
All outer surfaces must have a corrosion resistant surface coating to allow the vessel to be in-
stalled in certain environments without it causing corrosion.
Safety equipment
Before the vessel is put into operation, it must be provided with safety equipment. The manu-
facturer of the refrigeration plant is responsible for the safety equipment as it is not included
in the vessel delivery.
Start-up and operation
Before start-up, make sure that all connections are tight.
To avoid accidents or personal injury, the person responsible for the plant must make sure
that the operating staff is duly trained and instructed before the refrigeration plant is started.
The instruction should be based on the unit instruction manuals and should include instruc-
tions in construction, supervision, operation and maintenance of the system as well as the
handling of used refrigerant.
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Evacuation and charging with refrigerant must be carried out in accordance with the descrip-
tion in the unit instruction manual.
Before operation, the refrigeration plant must be leak tested and inspected by an authorised
person.
Local safety and health regulations must be observed.
The authorised person makes a certificate which must be kept by the user.
Bolted connections
Normal relaxing of the gasketed joints may occur in the interval between testing at the manu-
facturer’s and installation on site. Therefore, all external bolted joints may require retighten-
ing after installation and, if necessary, after the vessel has reached operating temperature.
It is important that all bolted joints are tightened evenly and in a diametrically staggered pat-
tern. All bolts must be tightened to the same torque using a torque wrench.
Maintenance
The vessel should be inspected at the inspection intervals stated in the compressor specifica-
tion. Only qualified personnel must carry out inspection.
Operating experience will determine how often inspection of the vessel is needed. It depends
on the operating conditions. Johnson Controls Denmark recommends inspection to be carried
out in monthly intervals during the running-in period. After a running-in period of six months,
a maintenance plan must be made. Johnson Controls Denmark recommends inspection to be
carried out every third month as a minimum.
Do not disconnect or tighten connections when the equipment is under pressure.
Periodic inspection during the service life of the vessel must meet the requirements of nation-
al legislation or EN 378-2. Correspondingly, a visual inspection of connections, outer surfaces,
bases, the vibration damper and safety equipment must be carried out.
If corrosion, erosion or other weaknesses in the vessel are found, the vessel must be inspec-
ted by a qualified authorised third party, who will provide the necessary permission to contin-
ue using it. If repair is requested, approved personnel together with a qualified third party
and Johnson Controls Denmark will carry this out. If permission to continue using the vessel is
not granted, it must be scrapped.
Disassembly for inspection or cleaning
Before disassembly, the user must make sure that the vessel has been depressurised, vented
and drained, neutralised and/or purged of hazardous material.
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Gasket connections
Gasket and gasket surface should be thoroughly cleaned and free of scratches and other de-
fects. The gasket should be properly positioned before attempting to retighten bolts. When a
vessel is dismantled for any cause, it must be reassembled with new gaskets. This will pre-
vent further leaks and/or damage to the gasket-seating surface of the vessel.
Spare parts and replacement parts
Spare parts and replacement parts can be ordered directly from Johnson Controls Denmark.
When ordering parts, please provide the name of the needed part as well as the vessel serial
number, type, size and other information from the name plate.
Environmentally correct removal
The vessel does not contain environmentally damaging material such as asbestos, mercury or
heavy metals.
All parts of the vessel can be re-used after being scrapped.
• Refrigerant and oil must be drained off before destruction
• All steel materials can be used again after remelting
• During the remelting process, the coating will disappear without harming the environ-
ment.
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Johnson Controls Denmark ApS
Christian X's Vej 201 ∙ 8270 Højbjerg ∙ Denmark
Phone +45 87 36 70 00 ∙ Fax +45 87 36 70 05 ∙ www.sabroe.com
CVR No 19 05 61 71
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