operational and maintenance manual · 2019-02-04 · be practical to place the heat exchanger in a...

OPERATIONAL AND MAINTENANCE MANUAL

Model Type:

Mfg. No(s):

CATALOG # 2002-005 Effective July 1, 2002

Design by TACO, consult TACOTaco Incorporated, 1160 Cranston Street, Cranston RI 02920 www.taco-hvac.com

TO AVOID HAND INJURIES, PROTECTIVE GLOVESSHOULD ALWAYS BE WORNWHEN HANDLING PLATES.

NOTICE

PROTECTIVE SHROUDS

IT IS THE RESPONSIBILITY OF EACH PERSON OPERATING ORREPAIRING EQUIPMENT TO TAKE THE NECESSARY PRECAUTIONSTO COMPLY WITH ALL APPLICABLE SAFETY REGULATIONS.

TACO PROVIDES PROTECTIVE SHROUDS FOR ALL OUR PLATEHEAT EXCHANGERS. THESE SHROUDS WILL PREVENT POSSIBLEINJURIES AND/OR DAMAGE AS A RESULT OF SUDDEN LEAKAGEFROM THE PLATE PACKAGE.

List of contents

TO OUR VALUED CUSTOMER 1

• TACO Locations 1.1

THE NAME PLATE - AND THE 2

IDENTIFICATION OF THE EQUIPMENT

• Code Plate & Identification Number Locations 2.1, 2.2

GENERAL 3

• Storage 3.1, 3.2

• Lifting 3.3

• Foundation 3.4

• Installation 3.5

• Special Loose Flange Connections 3.6

THE MAIN COMPONENTS AND THEIR FUNCTIONS 4A

FOR PARALLEL FLOW UNITS

• List of Parallel Flow Units 4A.1

• Function 4A.2

• How It Works 4A.3

• Heat Transfer 4A.4

• Pressure Drop 4A.4

• Plates 4A.5

• Gaskets 4A.6, 4A.7, 4A.8

• Pressure Plate Connection Style 4A.9, 4A.10

OPERATION 5

• Starting Up 5.1, 5.2

• Unit in Operation 5.3

• Shut Down 5.3

• The Risks of Not Complying With 5.4

The Start-Up and Shut-Down Procedures

CHAPTER

List of contents

OPENING AND CLOSING OF THE PLATE PACKAGE 6

• Opening 6.1, 6.2, 6.3, 6.4, 6.5

• Removal and Insertion of plates 6.6

• Closing 6.7, 6.8, 6.9, 6.10, 6.11

MAINTENANCE 7

• Cleaning 7.1, 7.2, 7.3, 7.4, 7.5

• Regasketing 7.6, 7.7, 7.8, 7.9

• End Plate II Gaskets For Parallel Flow Units 7.10

FAULT DETECTION 8

• Leakage at Connections or Plates 8.1, 8.2

• Internal Mixing of Media 8.3

• Pressure Drop Problems 8.4

• Heat Transfer Problems 8.5

SUPPLEMENTARY PARTS 9

• Partition Plate 9.1

CHAPTER

To our valued customer:

Thank you for purchasing a TACO Plate and Frame Heat Exchanger. As a world leader inthe manufacture of Heat Exchangers and other HVAC equipment, we are very proud of ourproducts and services. We value you as our customer and wish to assure your satisfaction.We have prepared this Instruction Manual to assist you with your TACO Plate and FrameHeat Exchanger in various situations. We suggest that you look through it carefully, and,above all, make it readily available to any personnel who may need it for reference.

We would appreciate any comments you have about our products and/or services.Please contact our local Representative who is listed in our Internet web site at(www.TACO-HVAC.COM) or either of the TACO facilities listed below. We do stand behindour products and services, and wish to thank you again for your confidence in TACO.

TACO, Inc.Corporate Headquarters1160 Cranston StreetCranston, RI 02920Phone 401-942-8000Fax 401-942-2360

TACO, Inc.Heat Transfer Division583 Bedford StreetFall River, MA 02720Phone 508-675-7300Fax 508-674-5932

List of contents

OPENING AND CLOSING OF THE PLATE PACKAGE 6

• Opening 6.1, 6.2, 6.3, 6.4, 6.5

• Removal and Insertion of plates 6.6

• Closing 6.7, 6.8, 6.9, 6.10, 6.11

MAINTENANCE 7

• Cleaning 7.1, 7.2, 7.3, 7.4, 7.5

• Regasketing 7.6, 7.7, 7.8, 7.9

• End Plate II Gaskets For Parallel Flow Units 7.10

FAULT DETECTION 8

• Leakage at Connections or Plates 8.1, 8.2

• Internal Mixing of Media 8.3

• Pressure Drop Problems 8.4

• Heat Transfer Problems 8.5

SUPPLEMENTARY PARTS 9

• Partition Plate 9.1

CHAPTER

To our valued customer:

Thank you for purchasing a TACO Plate and Frame Heat Exchanger. As a world leader inthe manufacture of Heat Exchangers and other HVAC equipment, we are very proud of ourproducts and services. We value you as our customer and wish to assure your satisfaction.We have prepared this Instruction Manual to assist you with your TACO Plate and FrameHeat Exchanger in various situations. We suggest that you look through it carefully, and,above all, make it readily available to any personnel who may need it for reference.

We would appreciate any comments you have about our products and/or services.Please contact our local Representative who is listed in our Internet web site at(www.TACO-HVAC.COM) or either of the TACO facilities listed below. We do stand behindour products and services, and wish to thank you again for your confidence in TACO.

TACO, Inc.Corporate Headquarters1160 Cranston StreetCranston, RI 02920Phone 401-942-8000Fax 401-942-2360

TACO, Inc.Heat Transfer Division583 Bedford StreetFall River, MA 02720Phone 508-675-7300Fax 508-674-5932

2 The name plateAND THE IDENTIFICATION OF THE EQUIPMENT

Model type and manufacturing numbers(s)

A name plate like the one shown below is fixed to the apparatus as shown above andit gives the following information:

2The name plateAND THE IDENTIFICATION OF THE EQUIPMENT

WHENEVER USING THE MANUAL, CHECK FIRST THAT THESERIAL NUMBER ON THE FRONT COVER IS IDENTICAL TOTHAT ON THE NAME PLATE OF THE EQUIPMENT.

IN ALL CORRESPONDENCE WITH TACO, INC., PLEASE REFERTO THE MANUFACTURING SERIAL NUMBER, FOR TRUEIDENTIFICATION OF THE EQUIPMENT.

WHENEVER CONTACTING TACO, INC. ABOUT A PART FORYOUR PLATE HEAT EXCHANGER, BE SURE TO STATE THEMANUFACTURING SERIAL NO(S), AND MODEL TYPE.

This instruction manual has been issued for many differentmodels of TACO PHEs.

2 The name plateAND THE IDENTIFICATION OF THE EQUIPMENT

Model type and manufacturing numbers(s)

A name plate like the one shown below is fixed to the apparatus as shown above andit gives the following information:

2The name plateAND THE IDENTIFICATION OF THE EQUIPMENT

WHENEVER USING THE MANUAL, CHECK FIRST THAT THESERIAL NUMBER ON THE FRONT COVER IS IDENTICAL TOTHAT ON THE NAME PLATE OF THE EQUIPMENT.

IN ALL CORRESPONDENCE WITH TACO, INC., PLEASE REFERTO THE MANUFACTURING SERIAL NUMBER, FOR TRUEIDENTIFICATION OF THE EQUIPMENT.

WHENEVER CONTACTING TACO, INC. ABOUT A PART FORYOUR PLATE HEAT EXCHANGER, BE SURE TO STATE THEMANUFACTURING SERIAL NO(S), AND MODEL TYPE.

This instruction manual has been issued for many differentmodels of TACO PHEs.

2. Preferably, the heat exchanger should bestored inside, in a room with a temperaturearound 15 to 20 degrees Celsius (60 to 70degrees Fahrenheit) and humidity around 70%.

3. Wrapping the PHE with a non-transparent plastic film is a good precaution. Use of transparent film can alter paint color if unit is stored in direct sunlight.

GeneralSTORAGE

STORAGE

In this section, names of heat exchanger parts are mentioned forthe first time. For your information, see Chapters 4A or 4B FUNCTION.

1. Unless otherwise agreed, TACO delivers the plate heat exchanger ready to be put in service upon arrival. This means that the plate package is tightened to its correct measurement A.

Should it be necessary, however, to store the equipment for alonger period (1 month or more) before, certain precautions shouldbe made in order to prevent unnecessary wear of the equipment:

There should ABSOLUTELY NOT be anyOZONE-PRODUCING equipment in theroom, like electric motors or arc-weldingequipment, since ozone destroys many rubber materials (cracking).

Do not store organic solvents or acids in the room.

Avoid heat or ultraviolet radiation.

STORAGE

GeneralSTORAGE

The tightening bolts should be well coveredwith good rust preventing coating, suitabletypes (LUBRIPLATE FGL-2 or Equivalent) and ifnot connected to the pipe system, theconnections should be covered.

If the heat exchanger must be stored outdoors,the precautions mentioned above should betaken as far as practical. The need forprotection against the climate etc. is of courseeven more important in this case.

If for any reason the heat exchanger is removedfrom service for a long period, it is advantageousto follow the advice above, even if the equipmentis not moved from the location.

The heat exchanger should be VENTED ANDDRAINED, and depending on the mediaprocessed, RINSING AND DRYING isrecommended before it is stored.

Whenever the heat exchanger is lifted, strapsshould be placed around tightening bolts onboth sides of the unit, as shown in picture. Iflifting lugs or lifting eyes are provided, alwaysuse chains or lifting cables rated above thepublished weight of the heat exchanger.

LIFTING

NEVER LIFT BY THE CONNECTIONS OR THE STUDS AROUND THEM!

2. Preferably, the heat exchanger should bestored inside, in a room with a temperaturearound 15 to 20 degrees Celsius (60 to 70degrees Fahrenheit) and humidity around 70%.

3. Wrapping the PHE with a non-transparent plastic film is a good precaution. Use of transparent film can alter paint color if unit is stored in direct sunlight.

GeneralSTORAGE

STORAGE

In this section, names of heat exchanger parts are mentioned forthe first time. For your information, see Chapters 4A or 4B FUNCTION.

1. Unless otherwise agreed, TACO delivers the plate heat exchanger ready to be put in service upon arrival. This means that the plate package is tightened to its correct measurement A.

Should it be necessary, however, to store the equipment for alonger period (1 month or more) before, certain precautions shouldbe made in order to prevent unnecessary wear of the equipment:

There should ABSOLUTELY NOT be anyOZONE-PRODUCING equipment in theroom, like electric motors or arc-weldingequipment, since ozone destroys many rubber materials (cracking).

Do not store organic solvents or acids in the room.

Avoid heat or ultraviolet radiation.

STORAGE

GeneralSTORAGE

The tightening bolts should be well coveredwith good rust preventing coating, suitabletypes (LUBRIPLATE FGL-2 or Equivalent) and ifnot connected to the pipe system, theconnections should be covered.

If the heat exchanger must be stored outdoors,the precautions mentioned above should betaken as far as practical. The need forprotection against the climate etc. is of courseeven more important in this case.

If for any reason the heat exchanger is removedfrom service for a long period, it is advantageousto follow the advice above, even if the equipmentis not moved from the location.

The heat exchanger should be VENTED ANDDRAINED, and depending on the mediaprocessed, RINSING AND DRYING isrecommended before it is stored.

Whenever the heat exchanger is lifted, strapsshould be placed around tightening bolts onboth sides of the unit, as shown in picture. Iflifting lugs or lifting eyes are provided, alwaysuse chains or lifting cables rated above thepublished weight of the heat exchanger.

LIFTING

NEVER LIFT BY THE CONNECTIONS OR THE STUDS AROUND THEM!

3GeneralFOUNDATIONS.

All information necessary for the preparation of the foundationappears on the data sheet provided by TACO.

In some cases (installation on board a ship,when processing corrosive liquids, etc.) it maybe practical to place the heat exchanger in aDRAINAGE BOX (with capacity for the totalvolume of the heat exchanger). The outlet ofthe drainage box should be generouslydimensioned, not less than (2”) 50 mm diameter.

INSTALLATION.

BEFORE connecting any piping to the heat exchanger, MAKE SURE THAT ALLFOREIGN OBJECTS HAVE BEEN FLUSHED OUT OF THE SYSTEM!

PLEASE OBSERVE THATThe measurements given in the picture aboveare recommended by TACO, it is necessary toleave free space around the equipment, toprovide access and make future service possible. Except for a place to put the plates,if removed from the heat exchanger, NO FURTHER SPACE is required for servic-ing the PHE.

PLEASE OBSERVE THATThe measurements given in the picture arerecommended by TACO, to provide reason-ably good working conditions during installa-tion of the heat exchanger as well as for futuremaintenance and service. If floor space isrestricted, the dimensions suggested can bereduced. It is left to the purchaser to decidejust how much access space is required.

Recommended free space foropening and closing.

This field should be kept freefrom fixed installations.

4”(100mm)

2” (50mm)

Wx1.5 Wx1.5 Wx1.5

GeneralLIFTING

LIFTING CONTINUED

If Lifting Lugs are provided

If you are to lift the heat exchanger itself,straps should be used. They should be placedas shown on the picture.

On smaller units (4” connected size smaller)typically two lifting lugs are required instead of four.

WARNING!Never lift by the connections or thestuds around them.

3GeneralFOUNDATIONS.

All information necessary for the preparation of the foundationappears on the data sheet provided by TACO.

In some cases (installation on board a ship,when processing corrosive liquids, etc.) it maybe practical to place the heat exchanger in aDRAINAGE BOX (with capacity for the totalvolume of the heat exchanger). The outlet ofthe drainage box should be generouslydimensioned, not less than (2”) 50 mm diameter.

INSTALLATION.

BEFORE connecting any piping to the heat exchanger, MAKE SURE THAT ALLFOREIGN OBJECTS HAVE BEEN FLUSHED OUT OF THE SYSTEM!

PLEASE OBSERVE THATThe measurements given in the picture aboveare recommended by TACO, it is necessary toleave free space around the equipment, toprovide access and make future service possible. Except for a place to put the plates,if removed from the heat exchanger, NO FURTHER SPACE is required for servic-ing the PHE.

PLEASE OBSERVE THATThe measurements given in the picture arerecommended by TACO, to provide reason-ably good working conditions during installa-tion of the heat exchanger as well as for futuremaintenance and service. If floor space isrestricted, the dimensions suggested can bereduced. It is left to the purchaser to decidejust how much access space is required.

Recommended free space foropening and closing.

This field should be kept freefrom fixed installations.

4”(100mm)

2” (50mm)

Wx1.5 Wx1.5 Wx1.5

GeneralLIFTING

LIFTING CONTINUED

If Lifting Lugs are provided

If you are to lift the heat exchanger itself,straps should be used. They should be placedas shown on the picture.

On smaller units (4” connected size smaller)typically two lifting lugs are required instead of four.

WARNING!Never lift by the connections or thestuds around them.

3 GeneralINSTALLATION

Always ensure that no measurable stress isplaced on the heat exchanger by the pipingsystem.

SHUT OFF VALVES

To enable the heat exchanger to be openedwhen necessary shut off valves should be pro-vided on all connections.

PRESSURE RELIEF DEVICES

It is the responsibility of the user to ensure thatthe required pressure relief devices are proper-ly installed prior to initial operation. Refer tothe applicable Code(s) and correspondingStandard(s) for proper size requirements ofthese pressure relief devices.

CONNECTIONS ON THE PRESSURE PLATE(REAR COVER)

Some plate heat exchangers may also haveconnections on the pressure plate. In suchcases, it is important to check against thedrawing or the name plate that the plate packhas been tightened to the right measurementbefore the piping is connected.

Whenever piping is connected to the pressureplate, a short 90o spool piece shall be installedbetween the heat exchanger and the piping.These should be directed upwards or side-ways. This simplifies pressure plate removalduring servicing.

Venting of both sides of the heat exchangermust be provided. This is important andenables air to be drawn from the system dur-ing start-up. It also enables air or gas to beremoved during operation, and it enablesfaster drainage.

3GeneralSPECIAL LOOSE FLANGE CONNECTIONS

Loose Flanges are provided on certain modeltypes due to interference. When provided theseflanges shall be incorporated into the piping.

MODELS WITH BOTH "S" AND "T" PORTCONNECTIONS:

TPX133LW-H1, TPX151L-H1, TPX151LD-H1,TPX161-H1, TPX237L-H1, TPX258H-H1,TPX258HD-H1, TPX258HW-H1, TPX915L-H1*,TPX915LW-H1*

MODEL TYPES WITH LOOSE FLANGE ON T PORT CONNECTIONS ONLY:

TPX133LW-M2, TPX151L-M2, TPX151LD-M2,TPX161-M2, TPX237L-M2, TPX258H-M2,TPX258HD-M2, TPX258HW-M2, TPX915L-M2*,TPX915LW-M2*

* Loose flange only when design pressuresabove 230 psi.

Notes:1) Port connections on these model types

utilized industry standard flanges.2) Not all exchangers require T port

connections.

PIPING CONNECTION

The loose flange is connected to piping by useof a commercially available stub end of samematerial as the piping.

The stub end is installed as shown and thenbutt weld to the piping.

3 GeneralINSTALLATION

Always ensure that no measurable stress isplaced on the heat exchanger by the pipingsystem.

SHUT OFF VALVES

To enable the heat exchanger to be openedwhen necessary shut off valves should be pro-vided on all connections.

PRESSURE RELIEF DEVICES

It is the responsibility of the user to ensure thatthe required pressure relief devices are proper-ly installed prior to initial operation. Refer tothe applicable Code(s) and correspondingStandard(s) for proper size requirements ofthese pressure relief devices.

CONNECTIONS ON THE PRESSURE PLATE(REAR COVER)

Some plate heat exchangers may also haveconnections on the pressure plate. In suchcases, it is important to check against thedrawing or the name plate that the plate packhas been tightened to the right measurementbefore the piping is connected.

Whenever piping is connected to the pressureplate, a short 90o spool piece shall be installedbetween the heat exchanger and the piping.These should be directed upwards or side-ways. This simplifies pressure plate removalduring servicing.

Venting of both sides of the heat exchangermust be provided. This is important andenables air to be drawn from the system dur-ing start-up. It also enables air or gas to beremoved during operation, and it enablesfaster drainage.

3GeneralSPECIAL LOOSE FLANGE CONNECTIONS

Loose Flanges are provided on certain modeltypes due to interference. When provided theseflanges shall be incorporated into the piping.

MODELS WITH BOTH "S" AND "T" PORTCONNECTIONS:

TPX133LW-H1, TPX151L-H1, TPX151LD-H1,TPX161-H1, TPX237L-H1, TPX258H-H1,TPX258HD-H1, TPX258HW-H1, TPX915L-H1*,TPX915LW-H1*

MODEL TYPES WITH LOOSE FLANGE ON T PORT CONNECTIONS ONLY:

TPX133LW-M2, TPX151L-M2, TPX151LD-M2,TPX161-M2, TPX237L-M2, TPX258H-M2,TPX258HD-M2, TPX258HW-M2, TPX915L-M2*,TPX915LW-M2*

* Loose flange only when design pressuresabove 230 psi.

Notes:1) Port connections on these model types

utilized industry standard flanges.2) Not all exchangers require T port

connections.

PIPING CONNECTION

The loose flange is connected to piping by useof a commercially available stub end of samematerial as the piping.

The stub end is installed as shown and thenbutt weld to the piping.

4AParallel Flow UnitsFUNCTION

THE MAIN COMPONENTS OF THE PLATE HEAT EXCHANGER AND THEIR FUNCTIONS.

In TACO Plate Heat Exchangers, heat is transferred from one medium to another through thinmetal plates which have been pressed into a special pattern.

3. CONNECTIONSHoles matching the piping leadthrough the frame plate, permittingthe media to enter into the heatexchanger. Threaded studs aroundthe holes secure the pipes to theequipment. Depending on the application, metallic or rubber-typeLININGS may protect the edges ofthe holes against corrosion.

6. TIGHTENING BOLTSWith the package of thin plateshanging between the frame plateand the pressure plate, a number of TIGHTENING BOLTS are used to press the thin plates together,bringing them into metallic contact,and to compress the gaskets,enough to seal off the narrowpassages which have now been formed between the plates.

8. CHANNEL PLATES

9. GASKETThese plates are called CHANNELPLATES. A groove along the rim of the plate and around the portshold a GASKET, usually made of a rubber-type material.

Heat is transferred through the surface which is contained by thegasket, except for some small areasnear the corners.

The number of plates in your heat exchanger is determined by the sizeof the heat transfer surface required.

1.2. 3.

4A Parallel Flow UnitsLIST OF PARALLEL FLOW UNITS

TPX34-M5

TPX92L-M2

TPX133LW-M2: TPX133LW-H1

TPX151L-M2; TPX151LD-M2; TPX151L-H1; TPX151L-DH1

TPX161-M2; TPX161-H1

TPX237L-M2; TPX237L-H1

TPX258H-L3; TPX258H-M2; TPX258H-H1

TPX258HD-M2; TPX258HD-H1

TPX258HW-M2; TPX258HW-H1

TPX306L-M2

TPX667H-M2; TPX667H-H1; TPX667H-H3

TPX667L-M2: TPX667L-H1; TPX667L-H3

TPX915L-L3; TPX915L-M2; TPX915L-H1

TPX915LW-M2; TPX915LW-H1

TPX1668UL-M2; TPX1668UL-H1

TPX1668ULL-M2; TPX1668ULL-H1

1. FRAME PLATE

2. SUPPORT COLUMNThe two bars are suspended between the FRAME PLATE, to which in most cases the piping is connected, and a SUPPORT COLUMN.

4. CARRYING BAR

5. GUIDING BARThe plates hang from a CARRYINGBAR at the top and are kept in lineby a GUIDING BAR at the bottom.

7. PRESSURE PLATEThe pressure plate is hung on thecarrying bar and is moveable, as are the heat transfer plates. In somecases piping may be connected tothe pressure plate.

4AParallel Flow UnitsFUNCTION

THE MAIN COMPONENTS OF THE PLATE HEAT EXCHANGER AND THEIR FUNCTIONS.

In TACO Plate Heat Exchangers, heat is transferred from one medium to another through thinmetal plates which have been pressed into a special pattern.

3. CONNECTIONSHoles matching the piping leadthrough the frame plate, permittingthe media to enter into the heatexchanger. Threaded studs aroundthe holes secure the pipes to theequipment. Depending on the application, metallic or rubber-typeLININGS may protect the edges ofthe holes against corrosion.

6. TIGHTENING BOLTSWith the package of thin plateshanging between the frame plateand the pressure plate, a number of TIGHTENING BOLTS are used to press the thin plates together,bringing them into metallic contact,and to compress the gaskets,enough to seal off the narrowpassages which have now been formed between the plates.

8. CHANNEL PLATES

9. GASKETThese plates are called CHANNELPLATES. A groove along the rim of the plate and around the portshold a GASKET, usually made of a rubber-type material.

Heat is transferred through the surface which is contained by thegasket, except for some small areasnear the corners.

The number of plates in your heat exchanger is determined by the sizeof the heat transfer surface required.

1.2. 3.

4A Parallel Flow UnitsLIST OF PARALLEL FLOW UNITS

TPX34-M5

TPX92L-M2

TPX133LW-M2: TPX133LW-H1

TPX151L-M2; TPX151LD-M2; TPX151L-H1; TPX151L-DH1

TPX161-M2; TPX161-H1

TPX258HD-M2; TPX258HD-H1

TPX306L-M2

TPX667L-M2: TPX667L-H1; TPX667L-H3

TPX915L-L3; TPX915L-M2; TPX915L-H1

TPX1668UL-M2; TPX1668UL-H1

TPX1668ULL-M2; TPX1668ULL-H1

1. FRAME PLATE

2. SUPPORT COLUMNThe two bars are suspended between the FRAME PLATE, to which in most cases the piping is connected, and a SUPPORT COLUMN.

4. CARRYING BAR

5. GUIDING BARThe plates hang from a CARRYINGBAR at the top and are kept in lineby a GUIDING BAR at the bottom.

7. PRESSURE PLATEThe pressure plate is hung on thecarrying bar and is moveable, as are the heat transfer plates. In somecases piping may be connected tothe pressure plate.

Pressure drops are wasted energy.

All pipe systems and equipment included inthem offer resistance to media flowing throughthem.

Some pressure drop is unavoidable, but for a given PHE it should be kept as close as pos-sible to the designed value.

The formation of deposits on the heat transfersurfaces instantly leads to a reduction of thefree space between the plates. This means thatmore energy is needed to get the desired flowthrough the equipment.

It is clear that the fouling of the surfaces isundesirable.

Larger particles and fibers may also be drawninto the heat exchanger and clog the passageways if strainers or other means of protectionhave not been provided for.

A reduced ability by the heat exchanger to holdthe desired temperatures, in combination withan increased pressure drop on any of the media,indicates that fouling or clogging is taking place.

For corrective action, see MAINTENANCE and CLEANING.

Parallel Flow UnitsHEAT TRANSFER

The purpose of the equipment is to transfer heatfrom one medium to another. Heat passes veryeasily through the thin wall separating the twomedia.

The novel pattern into which the plate materialhas been formed not only gives strength andrigidity, but greatly increases the rate of heattransfer from the warmer medium to the metalwall and from the wall to the other medium.

This high heat flow through the walls can be seri-ously reduced by the formation of deposits ofvarious kinds on the wall surfaces.

The pattern of corrugation on TACO plates men-tioned above induces highly turbulent flow. Theturbulence gives strong resistance to the forma-tion of deposits on the plate surface; however, itcannot always eliminate fouling.

The deposits may increase the total “wall thick-ness” substantially, and they consist of materialsthat have a much lower thermal conductivity thanthe metal plate. Consequently a layer of depositscan severely reduce the overall heat transfer rate.

The deposits will be considered in the chapter onMAINTENANCE and CLEANING. At this point wewill only establish that this fouling is unwantedand can under certain circumstances, be harmfulto the heat exchanger because corrosion mayoccur under the deposits.

Pressure drop

4A Parallel Flow UnitsHOW IT WORKS

How it works

When a package of plates is pressed together,the holes at the corners form continuous tunnels or manifolds, leading the media (whichparticipate in the heat transfer process) fromthe inlets into the plate pack, where they are distributed in the narrow passages betweenthe plates.

Because of the gasket arrangement on theplates, and the placing of “A” and “B” platesalternately, the two liquids enter alternate passages, e.g. the warm liquid between evennumber passages, and cold liquid between oddnumber passages.

Thus the media are separated by a thin metalwall. In most cases the liquids flow in oppositedirections.

During the passage through the equipment, the warmer medium will give some of its heatenergy to the thin wall, which instantly loses itagain to the colder medium on the other side.

The warmer medium drops in temperature,while the colder one is heated up.

Finally, the media are led into similar hole-tunnels at the other end of the plates and discharged from the heat exchanger.

Pressure drops are wasted energy.

All pipe systems and equipment included inthem offer resistance to media flowing throughthem.

Some pressure drop is unavoidable, but for a given PHE it should be kept as close as pos-sible to the designed value.

The formation of deposits on the heat transfersurfaces instantly leads to a reduction of thefree space between the plates. This means thatmore energy is needed to get the desired flowthrough the equipment.

It is clear that the fouling of the surfaces isundesirable.

Larger particles and fibers may also be drawninto the heat exchanger and clog the passageways if strainers or other means of protectionhave not been provided for.

A reduced ability by the heat exchanger to holdthe desired temperatures, in combination withan increased pressure drop on any of the media,indicates that fouling or clogging is taking place.

For corrective action, see MAINTENANCE and CLEANING.

Parallel Flow UnitsHEAT TRANSFER

The purpose of the equipment is to transfer heatfrom one medium to another. Heat passes veryeasily through the thin wall separating the twomedia.

The novel pattern into which the plate materialhas been formed not only gives strength andrigidity, but greatly increases the rate of heattransfer from the warmer medium to the metalwall and from the wall to the other medium.

This high heat flow through the walls can be seri-ously reduced by the formation of deposits ofvarious kinds on the wall surfaces.

The pattern of corrugation on TACO plates men-tioned above induces highly turbulent flow. Theturbulence gives strong resistance to the forma-tion of deposits on the plate surface; however, itcannot always eliminate fouling.

The deposits may increase the total “wall thick-ness” substantially, and they consist of materialsthat have a much lower thermal conductivity thanthe metal plate. Consequently a layer of depositscan severely reduce the overall heat transfer rate.

The deposits will be considered in the chapter onMAINTENANCE and CLEANING. At this point wewill only establish that this fouling is unwantedand can under certain circumstances, be harmfulto the heat exchanger because corrosion mayoccur under the deposits.

Pressure drop

4A Parallel Flow UnitsHOW IT WORKS

How it works

When a package of plates is pressed together,the holes at the corners form continuous tunnels or manifolds, leading the media (whichparticipate in the heat transfer process) fromthe inlets into the plate pack, where they are distributed in the narrow passages betweenthe plates.

Because of the gasket arrangement on theplates, and the placing of “A” and “B” platesalternately, the two liquids enter alternate passages, e.g. the warm liquid between evennumber passages, and cold liquid between oddnumber passages.

Thus the media are separated by a thin metalwall. In most cases the liquids flow in oppositedirections.

During the passage through the equipment, the warmer medium will give some of its heatenergy to the thin wall, which instantly loses itagain to the colder medium on the other side.

The warmer medium drops in temperature,while the colder one is heated up.

Finally, the media are led into similar hole-tunnels at the other end of the plates and discharged from the heat exchanger.

Parallel Flow UnitsGASKETS

The GASKET is molded in one piece. The material is normally anelastomer, selected to suit the actual combination of temperature,chemical environment and possible other conditions that may be present.

The one-piece gasket consists of:1. One field gasket2. Two ring gaskets3. Links

The field gasket is by far the larger part containingthe whole heat transfer area and the two corners connected to it. The ring gaskets seal offthe remaining two corners.

These three pieces are held together by a fewshort links, which have no sealing function at all.Their purpose is simply to tie the pieces togetherand to add some support in certain areas. Onsome plate heat exchangers, the gasket is held inplace on the plate by means of a suitable cementor glue.

Parallel Flow UnitsPLATES

Studying the pictures, you will observe that on a plate hangingvertically, the gasket rests in a groove which includes the heattransfer area

and two corners on theleft side.

OR two corners on theright side.

Smaller rings surround thetwo remaining corners.

We decide that we will name the plates after these two situations.

An A-plate is aplate hanging withthe chevron pointingdownwards.

A B-plate is aplate hanging withthe chevron pointingupwards.

If we turn an A-plate upside down we will have a B-plate:

The GASKET is molded in one piece. The material is normally anelastomer, selected to suit the actual combination of temperature,chemical environment and possible other conditions that may be present.

The one-piece gasket consists of:1. One field gasket2. Two ring gaskets3. Links

The field gasket is by far the larger part containingthe whole heat transfer area and the two corners connected to it. The ring gaskets seal offthe remaining two corners.

These three pieces are held together by a fewshort links, which have no sealing function at all.Their purpose is simply to tie the pieces togetherand to add some support in certain areas. Onsome plate heat exchangers, the gasket is held inplace on the plate by means of a suitable cementor glue.

Parallel Flow UnitsPLATES

Studying the pictures, you will observe that on a plate hangingvertically, the gasket rests in a groove which includes the heattransfer area

and two corners on theleft side.

OR two corners on theright side.

Smaller rings surround thetwo remaining corners.

We decide that we will name the plates after these two situations.

An A-plate is aplate hanging withthe chevron pointingdownwards.

A B-plate is aplate hanging withthe chevron pointingupwards.

If we turn an A-plate upside down we will have a B-plate:

TRANSITION PLATETPX-151; TPX-161; TPX-237; TPX-258; TPX495; TPX-538;TPX-667; TPX-807; TPX915; TPX-1615; TPX-1981

Ring Gaskets

Collars (Metal)

Channel Plate Gaskets

Pressure Plate

As already demonstrated, the two media areeffectively kept apart by the ring and field gas-kets. To prevent intermixing of the media in thecorner areas where field and ring gaskets arevery close to each other, the link pieces have a number of slots which opens the area betweenthe field and ring gaskets to atmosphere. Any leakage of media across either gasket will escape from the heat exchanger through the slots.

It is important that these openings are keptclear. If they are not, there is a risk that shoulda leak occur in that region of the plate, theremight be a local pressure build-up, which couldallow one medium to mix with the other.

Care should be taken not to cut or scratch thegaskets while handling plates.

TRANSITION PLATETPX-151; TPX-161; TPX-237; TPX-258; TPX495; TPX-538;TPX-667; TPX-807; TPX915; TPX-1615; TPX-1981

Ring Gaskets

Collars (Metal)

Channel Plate Gaskets

Pressure Plate

As already demonstrated, the two media areeffectively kept apart by the ring and field gas-kets. To prevent intermixing of the media in thecorner areas where field and ring gaskets arevery close to each other, the link pieces have a number of slots which opens the area betweenthe field and ring gaskets to atmosphere. Any leakage of media across either gasket will escape from the heat exchanger through the slots.

It is important that these openings are keptclear. If they are not, there is a risk that shoulda leak occur in that region of the plate, theremight be a local pressure build-up, which couldallow one medium to mix with the other.

Care should be taken not to cut or scratch thegaskets while handling plates.

NON MACHINED PRESSURE PLATE

Sheet Lining

Pressed Collar

Ring Gasket

End Plate

Transition Plate

Parallel Flow UnitsPRESSURE PLATE CONNECTION STYLE

Rubber Gasket

Sheet Lining, samematerial in metal ring

Metal Ring

MACHINED PRESSURE PLATE

NON MACHINED PRESSURE PLATE

Sheet Lining

Pressed Collar

Ring Gasket

End Plate

Transition Plate

Rubber Gasket

Sheet Lining, samematerial in metal ring

Metal Ring

MACHINED PRESSURE PLATE

OperationSTARTING UP

5. Open the vent.

6. Start the Pump.

7. Open the valve slowly.

8. When all air is out, close the vent.

9. Repeat the procedure for the other media.

5 OperationSTARTING UP

BEFORE STARTING UP FOR THE FIRSTTIME OR AFTER A LONG TIME INSTORAGE: MAKE SURE THAT THE PLATEPACK IS COMPRESSED TO THECORRECT MEASUREMENT A! Checkwith the Drawing or Nameplate, which isprovided with each heat exchanger.

It is very important that the system towhich the heat exchanger is connected, isprotected against sudden and extremevariations of temperature and pressure.This is not only for the heat exchanger butalso for the pipe system itself and everypiece of equipment included in it.

This should be kept in mind whenever amaneuver is to be carried out, includingstarting up of the pumps in the system.

Before starting any pump, check whetherinstructions exist, telling you which pumpshould be started first.

Check that the valve between the pumpand the equipment, controlling the flowrate of the system which you are about tostart up is closed.

Check that the valve at the exit, if there isone, is fully open.

START UP

OperationSTARTING UP

5. Open the vent.

6. Start the Pump.

7. Open the valve slowly.

8. When all air is out, close the vent.

9. Repeat the procedure for the other media.

5 OperationSTARTING UP

BEFORE STARTING UP FOR THE FIRSTTIME OR AFTER A LONG TIME INSTORAGE: MAKE SURE THAT THE PLATEPACK IS COMPRESSED TO THECORRECT MEASUREMENT A! Checkwith the Drawing or Nameplate, which isprovided with each heat exchanger.

It is very important that the system towhich the heat exchanger is connected, isprotected against sudden and extremevariations of temperature and pressure.This is not only for the heat exchanger butalso for the pipe system itself and everypiece of equipment included in it.

This should be kept in mind whenever amaneuver is to be carried out, includingstarting up of the pumps in the system.

Before starting any pump, check whetherinstructions exist, telling you which pumpshould be started first.

Check that the valve between the pumpand the equipment, controlling the flowrate of the system which you are about tostart up is closed.

Check that the valve at the exit, if there isone, is fully open.

START UP

OperationTHE RISKS OF NOT COMPLYING WITH THE START-UP AND SHUT-DOWN PROCEDURES

Valves must be operated gradually. The longerthe pipes and the higher the flowrate, the moreimportant this becomes.

WATER HAMMER is the name given to a shortduration pressure peak, traveling along the pipeas a wave at the speed of sound, and resultingfrom a sudden deceleration of the motion of thefluid in a closed system.

Thus, it is usually related to the shutting down ofa system. However, when starting up a systemwith open valves and empty pipes, the fluid mayburst into some obstacle, like a fine mesh strain-er, a flow meter or a heat exchanger, causing asudden reduction of the flow velocity - if not acomplete halt, and so we may have the condi-tions of a Water Hammer.

In the worst case, the pressure surge caused bysuch a sudden stop of the motion of a fluid, canbe several times the normal pressure of thesystem.

Therefore it is very important for the protectionof the whole installation that start-ups andclose-downs are carried out with great care.

A liquid in motion in a pipe system represents a lot of energy, and it must be very carefully dealtwith.

Particularly when the fluid is stopped it is imper-ative that this is done smoothly.

NOTE!For this reason fast-closing valves should not beused unless the pipes of the system are veryshort.

5 OperationUNIT IN OPERATION & SHUT-DOWN

UNIT IN OPERATION

Any adjustment of the flowrates required tomaintain correct temperatures or pressuredrops should be made slowly, in order to pre-vent shocks to the system.

Problems in keeping up the performance ofthe heat exchanger may be caused by a

SHUT-DOWN

If the heat exchanger is going to be shut down - or if for any reasonthe pumps are to be stopped - the following procedure should befollowed:

change in some of the temperature condi-tions, the heat load or by fouling.

As long as the PHE is operating to satisfac-tion, it should be left without any interference.

1. First establish whether instructionsexist that specify which side should be stopped first.

2. SLOWLY CLOSE THE VALVE controlling the flowrate of the pumpyou are about to stop.

3. When the valve is closed, stop the pump.

4. Repeat the procedure for the other side.

5. Poor quality cooling water may behazardous to metallic materials.Typical examples are corrosion ofstainless steels and nickel alloys.

If for any reason the heat exchangeris shut down for a longer period(more than a number of days), itshould be drained, and dependingon the media processed, it is recommended to rinse and dry it.