Danfoss S19, SW19A-IG Installation, Commissioning And Maintenance

User Guide
Plate Type Heat Exchangers, Single plate & Semi-welded Installation, Commissioning and Maintenance
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User Guide | Plate Type Heat Exchangers, Single plate & Semi-welded - Installation, Commissioning and Maintenance
Introduction .............................................................................................................................................................................................................. 3
Safety alert notices ............................................................................................................................................................................................. 3
General .......................................................................................................................................................................................................................... 4
Design: Single plate and Semi-welded .............................................................................................................................................. 6
Frame ................................................................................................................................................................................................................... 6
Single Plates .................................................................................................................................................................................................... 6
Semi-welded plates (plate cassettes) ............................................................................................................................................ 6
Gaskets ................................................................................................................................................................................................................ 6
Description ................................................................................................................................................................................................................. 7
Right (R)/ Left (L) plates ........................................................................................................................................................................... 7
Right and left plates, Single plates .................................................................................................................................................. 7
Storage........................................................................................................................................................................................................................... 8
Installation ................................................................................................................................................................................................................. 8
Transport and lifting .................................................................................................................................................................................. 9
Piping system .........................................................................................................................................................................................................10
Filtration .................................................................................................................................................................................................. 10
Installing the pipe connections.......................................................................................................................................................10
Commissioning .....................................................................................................................................................................................................11
Start-up process .........................................................................................................................................................................................11
Shut-down ................................................................................................................................................................................................................12
Shut-down for a short period ...........................................................................................................................................................12
Shut-down for a long period .............................................................................................................................................................12
Maintenance ...........................................................................................................................................................................................................12
CIP cleaning ...................................................................................................................................................................................................12
Cleaning agents guidance ..................................................................................................................................................................12
Opening the plate heat exchanger ..............................................................................................................................................13
Mechanical/Manual Cleaning ...........................................................................................................................................................14
Plate/Cassette replacement ...............................................................................................................................................................15
Gasket replacement .................................................................................................................................................................................15
Closing the plate heat exchanger ..................................................................................................................................................16
Regular Service of the plate heat exchanger .........................................................................................................................17
Additional service for semi-welded heat exchanger .......................................................................................................17
Troubleshooting ..................................................................................................................................................................................................18
After sales service ...................................................................................................................................................................................... 19
Ordering parts .............................................................................................................................................................................................19
Modications to the heat exchanger ..........................................................................................................................................19
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User Guide | Plate Type Heat Exchangers, Single plate & Semi-welded - Installation, Commissioning and Maintenance
Introduction
Safety alert notices
This user guide is a guide for installation, commissioning and maintenance of plate type heat exchangers supplied by Danfoss. It is meant for those who are responsible for the installation, the use and maintenance of the heat exchangers. We recommend that you read this user guide carefully before commencing any work.
This user guide is applicable for all plate type heat exchangers produced and supplied by Danfoss.
Danfoss can not be held responsible or liable for damage as a result of incorrect installation, use and/or maintenance of Danfoss plate type heat exchanger or damage caused by as not complying with the instructions in this user guide.
Please note that our plate type heat exchangers are specially designed and built for the maximum design conditions (pressures, temperatures, capacities and type of uids) provided by the customer and stated on the nameplate.
The following must always be observed when installing or servicing plate heat exchangers:
Sudden pressure peaks beyond the maximum operating pressure (or pressure surges) which can occur during start-up or stopping of the system can severely damage the heat exchanger and should be prevented. Danfoss can not be held responsible for any damage as a result of any operation deviating from the original design conditions.
• Comply with national/local safety regulations
• Ensure that the heat exchanger is unpressurized
• Ensure that the heat exchanger is cooled down to a temperature below 40 °C (104 °F)
Warning symbols refer to safety alert notices. Warning/safety notices should be observed carefully to prevent:
Personal injury caused by:
• Wrong transport/lifting
• Burning/freezing as a result of touching parts with extreme temperatures.
• Burning/freezing/poisoning as a result of uncontrolled release of pressurized media
• Contact with chemicals
• Touching sharp edges of e.g plates or cassettes
Equipment damage caused by:
• Wrong transport/lifting
• Liquid hammering
• External forces
• Corrosion
• Chemical action
• Erosion
• Material fatigue
• Thermal and/or mechanical shock
• Freezing
• Blocking of the heat exchanger due to particles
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User Guide | Plate Type Heat Exchangers, Single plate & Semi-welded - Installation, Commissioning and Maintenance
1727
F1
F4
F1
B1
B2
B4
B3
F1
F4
F1
B1
B2
B4
B3
1727
General Identification of the heat exchanger
All plate type heat exchangers supplied by Danfoss are provided with a name plate positioned on the front (head) of the heat exchanger.
Single plate heat exchanger Nameplate
Month/year of production
Type designation
Serial number
Assembly (A) measure min.
Assembly (A) measure max.
Max. pressure drop
Min./max. working temp.
Inlet - outlet connections
Max. working pressure
Max. allowed test pressure
Total internal volume
Fluids per side
On this plate main technical details of the heat exchanger are specied. Before installation please make sure that the intended application is compliant with the name plate application data and use limitations.
MADE IN DENMARK
Plate heat exchanger type
S19
Serial No.
IRF76804
A-measure min.
159
A-measure max.
-
Max. dierential pressure
16
Min. working temperature
0
Inlet > outlet
Max. working pressure
Max. test pressure
Volume
Fluid
Month and year
12-2018
Marking
mm
mm
Bar
Max. working temperature
80
°C
Ref. Side
F4 - F1
16 16
/
/
/
/
/
/
Brine side
F3 - F2
20,820,8
23,523,5
WaterWater
MM-Y Y
(*)
°C
Bar
Bar
Ltr.
Semi-welded plate heat exchanger Nameplate
Month/year of production
Type designation
Serial number
Assembly (A) measure nominal
Tolerance -1.5%
Max. pressure drop
Min./max. working temp.
Inlet - outlet connections
Max. working pressure
Max. allowed test pressure
Total internal volume
Fluids per side
F2
A-measure
F3
Manufactured by Danfoss A/S, 6430 Nordborg, Denmark
Plate heat exchanger type
SW19A-IG
Serial No.
76803
A-measure Nominal*
159
Max. dierential pressure
16
Min. working temperature
0 80
Inlet > outlet
Max. working pressure
Max. test pressure
Volume
Fluid
Do not exceed above values at any time.
Please read instruction manual before installation, operation and maintenance.
mm
Bar
°C °C
Ref. Side
F4 - F1
16
20,8
23,5
NH₃
MADE IN DENMARK
Month and year
02-2019
Marking
Max. working temperature
/
Brine side
/
F3 - F2
/
16
/
20,8
/
23,5
/
PropGlycol
MM-Y Y
(*)
Bar
Bar
Ltr.
A-measure min.: A-measure Nominal - 1.5%
F2
A-measure
F3
Manufactured by Danfoss A/S, 6430 Nordborg, Denmark
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Fig. 1. Nameplate examples. (*) Danfoss Quality approval confirms PHE has passed leak test procedure
Do not exceed above values at any time.
Please read instruction manual before installation, operation and maintenance.
User Guide | Plate Type Heat Exchangers, Single plate & Semi-welded - Installation, Commissioning and Maintenance
General
(continued)
Datalist (example)
Drawing (example)
Each heat exchanger comes with a data list specifying key components and relevant
Customer: Contact person:
Project: E-mail:
HEX Type: SW40A-72-TM Engineer: IR
Unit: 1 (Parallel) Code: Date: 04-03-2019 16:28:08
Calculated parameters Unit Ref Side Brine Side
Flow Type Co-Current
Load kW 350,00
Inlet temperature °C -7,59 -1,00
Evaporating temperature °C -8,00
SuperHeating K 0,00
Outlet temperature °C -8,00 -5,00
Inlet/Outlet quality 0,000/0,667
Mass flow rate kg/h 1464,4 83899,1
Volumetric flow rate L/min 1346,458
Total pressure drop kPa 5,03 93,71
Pressure drop - In port kPa 0,63 5,20
Total area m 26,60
Surface margin % 8,7
LMTD K 4,48
HTC(Available / Required) W/m-K 3189/2935
Heat flux kW/m 13,158
Abs.Evaporating pressure bar 3,15
Port velocity m/s 0,09(Inlet)/15,22(Outlet) 3,23
Shear stress Pa 5,41 109,07
Properties of fluid Unit Ref Side Brine Side
Fluid Ammonia Ethylene glycol(25,00%)
Liquid viscosity mPa-s 0,1855 3,6207
Liquid density kg/m 649,1 1039,1
Liquid heat capacity kJ/kg-K 4,575 3,755
Liquid thermal conductivity W/m-K 0,583 0,451
Vapor viscosity mPa-s 0,0088
Vapor density kg/m 2,6
Vapor heat capacity kJ/kg-K 2,570
Vapor thermal conductivity W/m-K 0,023
Specification: Unit Ref Side Brine Side
HEX Type: SW40A-72-TM
Number of plates: 72
Max.number of plates in current frame:
Grouping: (35TM)/(36TM)
Plate thickness / material: 0,5mm / EN1.4301(AISI304)
Main Gasket / Ring Gasket: NITRIL HT (H) / CHLOROPRENE
Connection: DN 100 Flange cl. AISI316 PN16 DN 100 Flange cl. AISI316 PN16
Counter Flange Yes Yes
Frame type / color: C2L / RAL3020
Certification/Approval type: PED
Volume: L 26,28 28,7
Weight: kg 253,74
Min. wall temperature °C -7 -6,56
Design Temp. (Max/Min): °C 50/-12
Design Pressure(Max) Ref./Brine: bar 16/16
84
accessories as per specic customer order, heat exchanger dimensions, and an assembly drawing.
Fig. 2. Standard documentation datalist and drawing (examples)
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User Guide | Plate Type Heat Exchangers, Single plate & Semi-welded - Installation, Commissioning and Maintenance
Ro ller
C a rryin g bar
Head
Na m e P la t e
Tie bolt
Guiding bar
Plate /Cassette
Follo wer
Co lumn
Anchoring bra ck e ts
Design: Single plate and Semi-welded
Roller
Carrying bar
Column
Name Plate
Head
Anchoring brackets
Fig. 3. Construction of generic Semi-welded heat exchanger. Single Plate construction is identical except plates are not paired (welded) into cassettes.
Frame
The heat exchanger consists of a frame plate (head), a pressure plate (follower), a carrying bar, a guiding bar and a column. Tie bolts are used to
The ring gasket material is carefully selected to match the combination of temperature and chemical resistance requirements (e.g. NH₃ and
compressor oil on the welded side). press the plate package together. The size and number of bolts depend on the type of heat exchanger.
Gaskets
The following gasket types are used in Danfoss
plate type heat exchangers:
Single Plates
Single plate pack consists of single plates tted with a ow gasket on each plate to seal the plate pack. The number of plates, size and dimension depend on the thermal output required. The number of plates determines the total heat
• Sonderlock gaskets
• Glued gaskets
• Sonder Snap gaskets (semi-welded plate heat
exchangers, large range)
• Hang-on gaskets (semi-welded plate heat
exchangers) transfer area (surface).
Semi-welded plates (plate cassettes)
A plate cassette consists of two single ow plates welded together, creating a sealed ow channel. The cassettes are tted with two individual gaskets, a ring gasket and a eld gasket, to seal the plate pack preventing the intermixing of media. This gasket design allows the use of dierent gasket materials for the ring and eld gaskets respectively for best t to the actual media and temperature conditions.
Follower
Plate/Cassette
Guiding bar
Tie bolt
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Fig. 4. ”Hang-on” gasket
User Guide | Plate Type Heat Exchangers, Single plate & Semi-welded - Installation, Commissioning and Maintenance
Description
(Continued)
Right (R)/ Left (L) plates
Plates are designed in such a way that they can be used both as right and left plates by alternately turning them 180°. Semi-welded cassettes are not turned.
Right and left plates, Single plates:
On a right plate the ow runs from porthole 2 to 3 or reverse from porthole 3 to 2.
Standard gasket
First plate: Special gasket All portholes gasketed)
1
2
Head
4
3
Used on all plates except rst
R
On a left plate the ow runs from porthole 1 to 4
or reverse from porthole 4 to 1.
The opening of the corner portholes is described
in a “plate code index”. For instance 1234 means
that all corner portholes are open. Every plate
can be identied by the gasket conguration, the
plate code index, and the plate geometry (e.g.
thermal short or thermal long geometry).
Each plate rotated 180° relative to plate before/after
L
R
Last plate: plate without portholes
Follower
Connections:
1, 4: Brine 1 2, 3: Brine 2
Flow arrows shown are only indicative
Fig. 5. Single plates: Left and Right plates and flow
Refrigerant ow
First plate: Single plate with no gaskets
Ring gaskets h/l*
1
2
Head
4
3
Single plates x N
Ring gasket
Brine ow Field gasket
Follower
Last plate: Single plate without portholes
Cassettes x N
(total number of plates 2xN+2)
Connections:
1, 4: Refrigerant side, *Ring gasket high 2, 3: Brine side, *Ring gasket low
Flow arrows shown are only indicative
Fig. 6. Semi-welded plates (cassettes) have no Left and Right plates. Refrigerant always flows in port 1 and 4
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User Guide | Plate Type Heat Exchangers, Single plate & Semi-welded - Installation, Commissioning and Maintenance
Storage
Installation
If storing the plate heat exchanger for a longer period of time, i.e. more than one month/30 days, the following precautions should be taken to prevent unnecessary equipment damage:
Preferably the plate heat exchanger should be stored inside in dry conditions at room temperatures around 15 – 20 °C (59 – 68 °F) and a humidity of maximum 70%.
If this is not possibly, place the plate heat exchanger in a wooden box provided with a lining on the inside that will prevent against moisture penetration.
Foundation
Install the heat exchanger on a at foundation providing sucient support for the frame.
Space
Ensure enough space around the plate heat exchanger for servicing the unit (renewal of plates, tightening of the plate pack). As a rule, free space around the unit should be
1.5 to 2 x the width of the unit. See Fig. 7.
Rubber gasket material is sensitive to certain
agents and ultraviolet radiation.
• Plate heat exchangers must be stored in rooms with no ozone producing equipment such as electric motors or arc-welding equipment as ozone may destroy several rubber materials
• Plate heat exchangers should not be stored together with any organic solvents or acids in the room
• Do not expose the plate heat exchanger to ultraviolet radiation
Drip tray
Replaceable plate heat exchangers involve a risk of leakage. It is recommended to take this into account while installing. Preferably install a drip tray underneath the heat exchanger to prevent leakages onto the oor and/or harm to electrical equipment.
Screen plate
If the heat exchanger is being used with temperatures above 60 °C or with aggressive uids, we advise that you cover the heat exchanger with a screen plate to prevent the risk of human exposure to the surface and uids.
Min.
Fig. 7. Ensure enough free space for servicing the plate
heat exchanger
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User Guide | Plate Type Heat Exchangers, Single plate & Semi-welded - Installation, Commissioning and Maintenance
Installation
(Continued)
Transport and lifting
WARNING: To prevent personal injury always use appropriate hoisting equipment. If you are to lift the heat exchanger itself, straps should be used. The straps should be placed as shown in fig. 8.
Usually the heat exchanger will be supplied horizontally on a pallet.
The back side of the head will then be secured to the pallet. This allows the unit to be transported by means of a forklift truck.
Raising of the unit: see g. 8.
• Remove all tightening elements from the pallet
• Place straps around opposite bolts on each side
of the column (1)
• Lift the unit vertically from the pallet (2)
• Remove the pallet securely (3)
• Slowly lower the heat exchanger to the oor (4)
• Remove the straps at the unit bottom side (5)
• Lift one-sided in an appropriate lifting angle (6)
and follow the raising of the unit carefully.
Avoid any bumps or shocks
• Once the heat exchanger is in upright position
place the straps in the dedicated lifting eyes (7)
and lift the unit to its nal position (8)
• Remove the straps and mount the heat
exchanger securely to the oor
4
2
11
5
Fig. 8. Lifting instructions
Never lift the heat exchanger using any other method than described above. Never use the connections, studs or any intermediate plates (if fitted) for lifting (fig. 9).
3
6
8
7
Fig. 9. Lifting points not allowed
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User Guide | Plate Type Heat Exchangers, Single plate & Semi-welded - Installation, Commissioning and Maintenance
Piping system Filtration
If the uid in the plate heat exchanger contains particles larger than Ø0.5mm an inline lter should be tted.
Installing the pipe connections
Most plate heat exchangers are intended for counter-current ow directions, but some specic applications require co-current ow. Refer to name-plate for information on each specic plate heat exchanger.
Danfoss plate type heat exchangers are provided with various connection types depending on size, application and conditions.
Single plate heat exchangers come with threaded pipe connections or studded anges ready for counter/blind anges.
Semi-welded heat exchangers come with factory installed welding anges. The refrigerant side is hermetically closed by blind plates and pressurized with nitrogen.
When connecting the piping system to the plate heat exchanger make sure that the piping system does not subject the plate heat exchanger to stress or strain.
Before connecting any piping to the plate heat exchanger make sure to clean and flush the piping system thoroughly for any foreign objects.
Note:
• Identify actual ow inlets/outlets on the name
plate before commencing piping work
• Heavy piping should be supported. This will
prevent heavy forces on the plate heat
exchanger
• To be able to open/close and dismantle the
plate heat exchanger shut o valves should
be installed in all connections
• Remove anges from the plate heat exchanger
before connecting to the valve/piping system.
• Nitrogen pressurized refrigerant side must be
depressurized through the small valve in the
blind plate before removing the anges
• Always install exible connections on the
follower to prevent vibrations on the plate heat
exchanger. The exible connections also help
prevent expansion of the pipes, which could
be caused by temperature inuence
• Flexible connections must be tted
perpendicular to the header/follower
• Install vents on both sides of the plate heat
exchanger
• The vents should be tted on the highest point
in the direction of the media ow
• The installation must be tted with safety
valves according to current pressure vessel
regulations
Make sure that the piping system, connected to the plate heat exchanger, is secured against pressure peaks/ surges and temperature shocks!
When doing any welding in the flange/ valve/piping system make earthing to the piping opposite of the plate heat exchanger. Never use the heat exchanger for earthing as plates and gaskets might be severely damaged.
When fitting threaded pipe to the threaded plate heat exchanger connection make sure that the connection do not rotate during tightening as this might damage internal ring gaskets. A secure counter-hold is needed.
For studded flange connection, insert the gaskets before bolting the blind flanges to the end plate. Tighten the bolts evenly - do not over-tighten as this might damage bolts/threads.
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User Guide | Plate Type Heat Exchangers, Single plate & Semi-welded - Installation, Commissioning and Maintenance
Commissioning
Commissioning, control, maintenance and repair of the installation should be done by authorized, trained and properly instructed sta.
Before commissioning check if all connections are tted correctly.
Check the pressures and the temperatures of the media and make sure they are within the limits of the values specied on the name plate.
Start-up process Single plate heat exchanger
For plate heat exchangers with liquid on both sides (liquid/liquid ow) the ow with an operating temperature closest to the ambient temperature is to start rst, i.e.
Flow 1
Delta T to ambient temperature lowest
Flow 2
Delta T to ambient temperature highest
Start liquid flow 1 first, then liquid flow 2.
For both ows follow these steps:
• Vent the system fully
• Close shut o valve tted between pump and plate heat exchanger
• Fully open valve tted into return line from the plate heat exchanger
• Start the circulation pump usually placed at the inlet
• Gradually open the closed shut o valve between pump and plate heat exchanger
• Vent system again if necessary
The plate heat exchanger must not be subject to thermal or mechanical shock as this could lead to premature gasket failure.
Check during operation
For proper and safe operation
• Check the system for potential pressure pulses
caused by pumps or control valves. In case of
pressure pulses, stop operation and rectify
• Continuous pressure pulses could cause
fatigue issues of ow plates
• Check that no leakages appear from the unit
• Check that all vents are closed to prevent air
being sucked into the system
• Check that the operating conditions including
media temperatures and pressures are within
the limitations stated on the name plate.
These must not be exceeded
When in operation the conditions should not be changed. Media temperatures and pressures must be within the limitations stated on the name plate and should not be exceeded.
Start-up process Semi-welded heat exchanger
For semi-welded plate heat exchangers with refrigerant on one side and glycol/water on the other side, the glycol/water side, i.e. the liquid ow, must be started rst.
Start liquid flow first, then refrigerant flow.
For the liquid ow follow steps mentioned above. For refrigerant ow follow these steps:
• Keep shut-o valves at the plate heat exchanger connections closed, while evacuating the heat exchanger completely
• Gradually open the shut-o valve at the outlet for pressure equalization and subsequently gradually open the inlet to the heat exchanger
• Activate the refrigerant system following normal procedure
If a high pressure difference is present and refrigerant in liquid phase in connecting pipes, precautions should be taken to avoid liquid hammer. Liquid hammer may cause considerable damage to the equipment and cause refrigerant leakage to the ambient.
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User Guide | Plate Type Heat Exchangers, Single plate & Semi-welded - Installation, Commissioning and Maintenance
Shut-down
Shut-down for a short period
If the plate heat exchanger has to be shut down for a short period the following procedure should be followed:
• Gradually close the inlet control valve in the refrigerant (ow 2) circuit whilst maintaining the full ow in the liquid circuit (ow 1)
• For high temperature applications cool down the heat exchanger to below 40 °C ( 104 °F)
• Gradually close the inlet control valve in the liquid (ow 1) circuit
• Switch o the liquid (ow 1) circuit pump
Shut-down for a long period
If the unit is to be shut down for an extended
period of time then the following procedure
should be followed:
• Follow steps above
• Allow unit to reach ambient temperature
• Ensure a minimum amount of refrigerant in the
heat exchanger. Boil o using ow 1 in
evaporators or use liquid drain in condensers.
• Evacuate refrigerant side
• Drain ow 1 circuit
• Lubricate threads on the tie bolts
• Loosen tie bolts according to the instruction
in “opening the plate heat exchanger” section
until the length of the plate pack reaches:
- Single plate: A-measure max. +10%
- Semi-welded: A-measure Nominal +10%
• The tie bolts should not be removed or
loosened to such an extent that dirt is allowed
to enter in-between the plates. It is
recommended to attach a warning notice to
the plate heat exchanger to remind personnel
that the tie bolts need adjustment before the
unit can be put back into service
• Cover the plate pack with black plastic to
exclude any sunlight
Maintenance
CIP cleaning
Clean-in-Place, CIP cleaning, allows cleaning the plate heat exchanger without opening it and is done by circulating cleaning agents in the heat exchanger.
CIP cleaning of the refrigerant circuit is not allowed. CIP cleaning can be done only on the brine circuit.
The use of CIP cleaning is relevant for soluble fouling only. Prior to CIP cleaning ensure that all materials in the entire circulation system are resistant to the cleaning agent/CIP liquid used.
We advise to ask for a confirmation from the supplier of the cleaning agent that it will not damage the materials in the heat exchanger.
Cleaning agents guidance
Oil and grease can be removed with a water emulsifying oil solvent.
Organic and grease cover can be removed with sodium hydroxide (NaOH) maximum concentration 1.5% - max. temp. 85 °C (185 °F). Mixture for 1.5% concentration = 5 l 30% NaOH per 100 l water.
Check maximum allowable working temperature
on the name-plate mounted on the head of the
plate heat exchanger before performing CIP
cleaning. Maximum working temperature should
not be exceeded at any time. Consult Danfoss if
in doubt.
If the solution requires recirculation, select a ow
that is as high as possible, and no less than the
service or operation ows.
Follow the instructions from the supplier of the
cleaning agent. For re-circulated cleaning, we
recommend that uid is circulated in the plate
heat exchanger for no less than 30 minutes.
Rinsing
After using any type of cleaning agent, always
rinse the plate heat exchanger thoroughly with
fresh water. After CIP cleaning, circulate fresh
water for at least 10 minutes.
Nitric acid has an build up eect on the
passivation lm of stainless steel.
CAUTION: Nitric acid and Sodium Hydroxide may cause injury to exposed skin, eyes, and mucous membranes. Use of protective eyewear and gloves is strongly recommended.
Stone and limestone can be removed with nitric acid (HNO₃) - max. concentration 1.5% - max. temp. 65 °C. Mixture for 1.5% concentration = 2.4 l HNO₃ 62% per 100 l water.
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User Guide | Plate Type Heat Exchangers, Single plate & Semi-welded - Installation, Commissioning and Maintenance
Maintenance
(Continued)
Opening the plate heat exchanger
When opening and disassembling the plate heat exchanger observe the following:
• Mark the plate package before opening. This can be done by a diagonal line (see g. 10) or by numbering each individual plate in sequence
• Measure and note the actual assembly measure (Reference name plate for validation).
• Use appropriate tools and lubricant
• Shut down the heat exchanger as described in section "Shut down"
• Make sure the heat exchanger cools down (<40 °C (104 °F))
• The liquid side must be drained and the
refrigerant side must be properly evacuated
before the heat exchanger is opened
• Clean the tie bolts and grease the threads
• Loosen all the short tie bolts while leaving the
long tie bolts in tension
• Loosen the long tie bolts evenly in the
numbered order 1, 2, 3, 4 (g. 10) i.e. the
follower shall have a parallel opening motion
CAUTION: Ensure unit is depressurized and drained of hot and/or aggressive fluid before unit is opened to prevent personal injury.
A-measure
Diagonal line
Long tie bolt
1
3
4
Wrench
2
Clean and grease threads
Fig. 10. Opening the plate heat exchanger
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User Guide | Plate Type Heat Exchangers, Single plate & Semi-welded - Installation, Commissioning and Maintenance
Maintenance
(Continued)
Opening the plate heat exchanger (continued)
• Remove all tie bolts
• Pull the follower back towards the column
• Remove the plates/cassettes one by one without damaging the gaskets
CAUTION: Plates/cassettes have sharp edges! When handling plates/cassettes always wear gloves
Fig. 11. Removal of plates
Mechanical/Manual Cleaning
• Plates/Cassettes can be mechanically cleaned by use of water and a soft brush. Alternatively a high pressure cleaner might be used with caution and without abrasives
• If needed cleaning agents may be used
• Cassettes are only cleanable on the brine side and all precautions must be taken to avoid any water or cleaning agent entering the welded cassettes
• Consult a cleaning specialist for choosing a suitable cleaning agent. Ensure that all agents used are compatible with the plate/cassette and gasket material
CAUTION: Some cleaning agents may cause injury to exposed skin, eyes and mucous membranes. Use of protective eye-wear and gloves is strongly recommended.
Never allow any water or cleaning agent to enter the welded side of the cassettes.
Handle plates/casettes with gloves only
Soft brush
Fig. 12. Mechanical cleaning with soft brush
14 | BC172686461130en-000201 © Danfoss | DCS (ms) | 2019.07
User Guide | Plate Type Heat Exchangers, Single plate & Semi-welded - Installation, Commissioning and Maintenance
Maintenance
(Continued)
Mechanical Cleaning continued
Never use a metal brush, steel wool or sand/glass paper. This will damage the passivation film of the plates. Never use Hydrochloric for Stainless teel plates. Never use Hydrofluoric for Titanium plates.
• Always remove plates/cassettes one by one and number them in right order
• Plates/cassettes removed for manual cleaning must be re-tted in the same order
• Single plates may be immersed into a solvent bath to dissolve hard fouling
Plate/Cassette replacement
If a plate/cassette has to be renewed because of serious damage, it is recommended to replace the plates/ cassettes next to this plate/cassette.
• Plates/Cassettes must be replaced if damaged or not cleanable
• When ordering new plates/cassettes all data from the nameplate is required
• New plates/cassettes are supplied with complete gaskets ready for immediate installation
Before fitting chemical cleaned plates they need to be thoroughly rinsed with fresh water!
Gasket replacement
Glue free gaskets / Sonder Snap, Sonderlock & Hang-on gaskets
These gaskets are mounted without the use of any glue. They are positioned by pushing the gasket fully down into the gasket groove or fastened by special devices. Make sure groove and gasket are clean.
Glue type gaskets
The surfaces need to be clean and free of oil. Only use chloride free glues like Pliobond 20 or 30, Bostic 1782, 3M EC 1099 and Bond Spray 77. Follow the instructions of the manufacturer.
CAUTION: When using commercial solvents and adhesives, follow the manufacturers recommendations carefully. Most of these solvents are hazardous.
Semi-welded gaskets
The 2 types of gaskets in Semi-welded heat
exchangers - ring gaskets for refrigerant side
and eld gasket for liquid side - can be replaced
independently (see g. 6).
© Danfoss | DCS (ms) | 2019.07 BC172686461130en-000201 | 15
User Guide | Plate Type Heat Exchangers, Single plate & Semi-welded - Installation, Commissioning and Maintenance
cassette/plate package
cassette/plate package
Maintenance
(Continued)
Closing the plate heat exchanger
When assembling and closing the heat exchanger observe the following:
• Check that all gaskets are correctly positioned in the grooves
• Check that plates/cassettes are hanging correctly on the carrying bar
• Press the plate package together by pushing the follower
• Make sure the plates are in the correct position according to the marked diagonal or numbering
• Check the plate/cassette edge pattern for uniformity (see g. 13)
• Identify the A-measure noted prior to opening the heat exchanger (conrm with nameplate)
• Use appropriate tools and lubricant
• Ensure there is no ow to any part of the unit
• Clean the tie bolts and grease the threads
• Install the long tie bolts and tighten evenly in the numbered order 1, 2, 3, 4 (g. 14) until a resistance can be noticed. i.e. the follower shall have a parallel closing motion
• Tighten the long tie bolts in sequence 1 to 4 alternately until the A-measure has been reached at all long tie bolts
• Tighten the short tie bolts in an alternating order until the A-measure has been reached at all tie bolts
• Prepare for operation. Folow instructions in
section "Start-up process"
• If the heat exchanger does not seal immediately
the tie bolts can gradually be tightened to
A-measure minimum (see name plate)
The A-measure shall never be less than A-measure minimum.
Correctly assembled
Fig. 13. Correct/Incorrect assembled plate package
Incorrectly assembled
A-measure
1
3
Long tie bolt
Diagonal line
4
Wrench
2
Clean and grease threads
Fig. 14. Closing the plate heat exchanger. Note: The A-measure shall never be less than A-measure minimum (see name plate)
16 | BC172686461130en-000201 © Danfoss | DCS (ms) | 2019.07
User Guide | Plate Type Heat Exchangers, Single plate & Semi-welded - Installation, Commissioning and Maintenance
Maintenance
(Continued)
Regular Service of the plate heat exchanger
Service sequence – once a year as a minimum
• Check temperatures and ows against commissioning data
• Check general condition and look for any signs of leakage
• Wipe clean all painted parts and check surfaces for signs of damage – “touch up” if necessary
Additional service for semi-welded heat exchanger:
Clean uids/normal conditions Dirty uids/severe cconditions
2
Years
after
commis-
sioning
3 PHE audit
5
PHE audit
6
7
PHE audit
8
Leak
detection
refrigerant
Replace
ring- and
main body
gaskets**
Leak
detection
refrigerant
CIP
cleaning
Leak
detection
refrigerant
CIP
cleaning
• Check bolts and bars for rust and clean. Coat
threaded parts with molybdenum grease or a
corrosion inhibitor (ensure that no grease, etc.
falls onto the plate gaskets
• If rollers are tted to the follower, lubricate the
bearings with light machine oil
CIP and manual
cleaning
PHE audit
PHE audit
PHE audit
Leak
detection
refrigerant
Replace
ring- and
main body
gaskets**
Leak
detection
refrigerant
CIP and manual
cleaning
Leak
detection
refrigerant
CIP &
manual
cleaning
Replace
ring
gaskets*
CIP and
manual
cleaning
Replace
ring
gaskets*
10
Replace
ring- and
main body
gaskets**
12
13
PHE audit
15
Fig. 15. Guideline for service intervals for semi-welded plate heat exchangers. Indicative for clean fluids/normal conditions and dirty fluids/severe temperature-pressure conditions respectively
* Ring gasket kit
** Full gasket kit PHE audit: Visual inspection of operating conditions, leaks, corrosion and general condition Leak detection refrigerant: Electronic testing (sniffer) CIP: Clean in place (See section "clean in place") Manual cleaning: Plate pack disassembly/plate cleaning Replace gaskets: Plate pack disassembly/replace gaskets At extreme fluids/conditions audits should be performed more frequent
Leak
detection
refrigerant
Leak
detection
refrigerant
CIP and
manual
cleaning
CIP
cleaning
PHE audit
PHE audit
Replace
ring- and
main body
gaskets**
Leak
detection
refrigerant
Leak
detection
refrigerant
CIP &
manual
cleaning
CIP &
manual
cleaning
Replace
ring
gaskets*
© Danfoss | DCS (ms) | 2019.07 BC172686461130en-000201 | 17
User Guide | Plate Type Heat Exchangers, Single plate & Semi-welded - Installation, Commissioning and Maintenance
Troubleshooting
Most common problems with a plate heat exchanger, can be solved by own trained personnel. Fig.16 lists a summary of possible problems together with relevant possible causes and solutions.
Exceeding these values, even as short-lasting peaks, may damage the unit or could be the cause of problems/issues. To avoid costly repairs, it is recommended to have the installation and maintenance carried
out by properly trained personnel. To maintain a continuous proper function of the plate heat exchanger ,it is essential to keep the operating pressure and temperature within the ranges stated on the nameplate.
Problem Possible cause Possible solution
Check the rubber liners (if fitted)
Connection sealing damaged
Leakage
Insufficient capacity
Too high pressure drop
Fig. 16. Summary of possible problems, causes and solutions
Mixing of primary and secondary circuit
Plate package sealing damaged
The operating conditions deviate from the specification
Air in the system
The operating conditions deviate from the specification
The heat exchanger is fouled internally Clean the heat exchanger
The connections have been interchanged Redo the pipe work
Flow larger than the design flow Adjust the flow
Channels in plates blocked Flush / clean
Incorrect measurement Check the pressure indicator
Fluid deviating from the specification Check the chemical composition
Air in the system
For nearly all leakage problems it will be necessary to dismantle the unit before any attempts to rectify the fault can be made. Mark the area(s) where the leakage seems located with a felt tip marker or similar before disassembling the plate heat exchanger. Follow
“Cold leakage” is caused by a sudden change in
temperature. The sealing properties of certain
elastomers are temporarily reduced when the
temperature changes suddenly. No action is
required as the gaskets most often re-seal after
the temperature has stabilized.
Check the flange gasket (if fitted)
Check the ring gasket at first plate
Fit the pipes tension-free
Check the plates for holes and/or cracks
Single plate:
Semi-welded:
Check the assembly distance "A"
Check the condition of the gaskets
Check the proper position of the gaskets
Adjust the operating conditions
Vent the piping system
Check the pipe work for possible air traps
Adjust the operating conditions
Vent the piping system
Check the pipe work for possible air traps
the instructions in section "Opening the plate heat exchanger".
Check the gaskets around the port and diagonal areas
Check the diagonal part of the field gasket and ring gasket
18 | BC172686461130en-000201 © Danfoss | DCS (ms) | 2019.07
User Guide | Plate Type Heat Exchangers, Single plate & Semi-welded - Installation, Commissioning and Maintenance
Troubleshooting
(Continued)
After sales service
Gasket failures are generally a result of
• Material aging/degradation
• Excessive exposure to ozone
• High or low operating temperature - outside specied material limits
• Exposure to pressure surges
• Attack by chemicals from cleaning, refrigerants or oils
• Physical damage from incorrect assembly work
• Misaligned plates (check the hanging system at the top of the plate for distortion)
Decrease in performance is generally a result of
• Plate surfaces require cleaning or de-scaling
• Pumps or associated controls failing
• Plate channels blocked
Ordering parts
When ordering spare parts it is important to provide correct data for:
• Project and order number
• Plate heat exchanger type and manufacturing number (see name plate)
• Required parts
When ordering separate plates it is important that the correct plate code index and type of plate is given.
When ordering separate gaskets it is important to indicate the correct gasket material.
When ordering tie bolts, the existing bolts should be measured in order to get spare bolts with the same dimensions.
• Liquid ows not as specied
• Associated chiller / cooling tower / boiler under
sized or dirty
• Cooling uid temperature to the plate heat
exchanger is higher than the design
temperature
• Heating uid temperature to the plate heat
exchanger is lower than the design temperature
• Refrigerant trap broken or jammed – unit
becomes lled with condensate
• Plate package has been assembled incorrectly
• Plate heat exchanger is running with co-current
ow, instead of counter-current. (Check
direction of pump ows)
• Air trap has developed in the plate package or
piping work
Modifications to the heat exchanger
Please note that a plate heat exchanger is specic
designed and built for the operating parameters
(pressures, temperatures, capacity and type of
uids) initial provided by the customer.
If the plate heat exchanger needs to operate at a
dierent capacity this can be achieved by adding
or removing plates/cassettes.
Modication of the plate heat exchanger to
match other parameters may also be considered.
Consult Danfoss for redesign and/or approval of
any change to operating parameters.
After approval by Danfoss a new name plate will
be issued.
You may only commission a plate heat exchanger
under modied conditions after written approval
by Danfoss.
© Danfoss | DCS (ms) | 2019.07 BC172686461130en-000201 | 19
Danf
oss can accept no responsibility for possible errors in catalogues, brochures and other printed material. Danfoss reserves the right to alter its products without notice. This also applies to products
already on order pro All trademarks in this material are property of the respec
vided that such alterations can be made without subsequential changes being necessary eady agreed.
© Danfoss | DCS (ms) | 2019.07 BC172686461130en-000201 | 20
tive companies. Danfoss and the Danfoss logotype are trademarks of Danfoss A/S. All rights reserved.
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