Operation and MaintenanceManual

IM-R01-386AB Issue 1

01.09

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1 GENERAL .................................................................................................................................................. 4 1.1 INTRODUCTION ...................................................................................................................................... 4 1.2 PRODUCT FAMILY .................................................................................................................................. 4 1.3 DESIGN .................................................................................................................................................... 5

2 ASSEMBLY OF THE HEAT EXCHANGERS ................................................................................... 6 2.1 LIFTING .................................................................................................................................................... 6 2.2 PIPING ..................................................................................................................................................... 7 2.2.1 GENERAL ...................................................................................................................................... 7 2.2.2 STEAM APPLICATIONS (CONDENSER) ..................................................................................... 8 2.3 INSULATION ............................................................................................................................................ 8 2.4 PRESSURE TEST ................................................................................................................................... 8 2.5 BRACKETS .............................................................................................................................................. 9

3 ALLOWED OPERATIONS CONDITIONS ........................................................................................ 10 3.1 DESIGN CONDITIONS ............................................................................................................................ 10 3.2 FLUIDS ..................................................................................................................................................... 10 3.3 FLOW RATES .......................................................................................................................................... 10

4 PRINCIPLE OF FUNCTION AND START-UP OF PROCESS. ................................................... 11 4.1 PRINCIPLE OF THE HEAT EXCHANGERS............................................................................................ 11 4.1.1 LIQUID-LIQUID ............................................................................................................................... 11 4.1.2 CONDENSER......................................................................... ............................................................. 12 4.1.3 DX-EVAPORATOR ......................................................................................................................... 12 4.1.4 EVAPORATOR ............................................................................................................................... 13 4.1.5 SEPARATOR SYSTEM .................................................................................................................. 13 4.2 START-UP ................................................................................................................................................ 13 4.3 SHUT DOWN ........................................................................................................................................... 14

5 CLEANING OF THE HEAT EXCHANGER ...................................................................................... 15 5.1 GENERAL ................................................................................................................................................ 15 5.2 GUIDELINES FOR CLEANING ............................................................................................................... 15 5.3 OPENABLE MODEL ................................................................................................................................ 16 5.3.1 PRELIMINARY ACTIONS. ............................................................................................................. 16 5.3.2 OPENING THE UNIT AND REMOVING THE PLATE PACK ........................................................ 16 5.3.3 MOUNTING THE PLATE PACK .................................................................................................... 18 5.3.4 BOLT /STUD TIGHTENING PATTERN ......................................................................................... 19

6 SPARES ...................................................................................................................................................... 20

7 SERVICE / TROUBLESHOOTING ..................................................................................................... 21 7.1 CLAIM REPORT ....................................................................................................................................... 23 7.2 MEASURES FOR REPLACEMENT. ........................................................................................................ 23

All rights reserved.No part of this publication may be reproduced, stored in a retrieval

system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise without the

prior permission of Vahterus Oy. Plate & Shell and Plate & Ring are registered trademark of

Vahterus Oy.

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1.1 Introduction This manual is your general guide for the proper installation, operation and maintenance of your Vahterus Plate and Shell Heat Exchanger (PSHE). We ask you to read it and follow the instructions. PSHE is totally welded plate heat exchanger without any gaskets between the plates. Vahterus accepts no responsibility or liability for damage caused by incorrect installation, operation or maintenance due to failure in observing these instructions.

1.2 Product family

1. General

Plate & Shell®Fully welded model – welded pack of circular plates inside a fully welded, coded pressure vessel. For applications such as liquid – liquid, condensers, evaporators and cascades. These models cannot be opened. This kind of heat exchanger can be single or multi pass. (See chapter 4 Principle of the heat exchangers.)

Plate & Shell®, openableOpenable model. Fully welded plate pack inside an openable shell. The plate pack can withdrawn from the shell with a shell flange. This construction is used normally single pass

Plate & Shell®, CompactAll connections on the end plate. For liquid-liquid applications only. These can be single or multi pass..

Plate & Ring®A pack of circular ring plates within a fully welded shell. This construction is used for example for gas applications.

1.3 Design The Vahterus Plate and Shell Heat Exchangers are designed and manufactured according to the pressure vessel codes. The used relevant code is shown on the Vahterus technical data sheet : - ASME VIII Div.1, based on an individual design for the each heat exchanger. - PED 97/23/EC, the design is based on the type approvals. The type approval number and also the PED

category are shown on the Vahterus technical data sheet.

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2.1 LiftingAdequate space should be provided around the heat exchanger for mounting, insulation and maintenance. The distance to the nearest obstacle (e.g. wall) must be at least 500 mm. Also the space between adjacent exchangers must be more than 100 mm. To remove the plate pack out of the shell, in the case of an openable type heat exchanger, additional space equal to the total length should be available at the front of it.

The heat exchangers are provided with welded lifting lugs or lifting eye lugs.

When Heat Exchangers are combined with Separators it is necessary to take care when handling and positioning the unit due to the top heavy nature of the construction. It is essential that the total unit is supported by crane or another method from the lifting lugs provided until it is bolted in position.

It is also necessary to utilize the lifting lugs as well as the heat exchanger mounting bracket to secure the unit in position while in use.

Do not use the nozzles or the mounting brackets for lifting the exchanger.

WARNING Do not weld anything to the body of the heat exchanger (including the shell, end plates and the

sides of the connection pipes) without first consulting your Vahterus representative, since it can harm the inner structure of the heat exchanger.

2. Assembly of the heat exchangers

Lug Lifting Force

1T (Welded) 1000 kg

3T (Welded) 3000 kg

5T (Welded) 5000 kg

7T (Welded) 7000 kg

M16 (DIN 582) 700 kg

M20 (DIN 582) 1200 kg

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2.2 Piping 2.2.1 General

Install the unit so that the piping and heat exchanger can be drained. In Steam applications units must be vertically mounted for 2-phase operation.

Please check :

1. All piping is flushed prior to connecting the unit

2. All connections / nozzles are marked and should be piped according to the GA-drawing

3. Ensure flexibility in the piping system so that restricted thermal expansion of the piping does not over load the nozzles and no vibrations are transferred to the heat exchanger.

4. All pipe connections to the heat exchanger must be equipped with shut-off valves. It is recommended that all valves should have slow valve action. Flow rates should be increased slowly and gradually during start up and reduced gradually during shut down.

5. If there are solids in the process fluids, filters are recommended.

6. If there is a risk of exceeding the design pressure, make sure the pipeline is provided with adequate pressure relief valve.

7. If multiple units are arranged in parallel there should be sufficient control on the inlet lines to adjust flow rates to each unit.

Openable model Any pipe connection to the detachable end plates (on openable model) must be made either with flange or threaded connections.

2.2.2 Steam applications (Condenser)The pipelines should be manufactured according to good steam practices.

In steam applications please ensure the unit is oriented for gravity drainage of condensate.

It is recommended to install a moisture separator and steam trap before valve and after the heat exchanger, respectively to avoid accumulation of condensate in the heat exchanger. This will avoid the water content increasing in the steam and entering the heat exchanger.

When the water steam is on the shell side, the heat exchanger is provided with a steam baffle, which is assembled in the HOT IN connection. However the customer should aim to prevent any steam hammer in the heat exchanger.

WARNING When the valve is closed, the condensate might accumulate in the pipeline. Thus when the valve will be opened, the differential pressure will pull the accumulated water into heat exchanger at high speed. This might cause mechanical damage to the heat exchanger.

NOTE When the unit is operating with vacuum or partial-vacuum steam, the installation of condensate pumps must be considered.

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2.3 Insulation Depending on temperature (below –10 ºC or above 80 ºC on shell side) the use insulation is recommended to protect personnel from burns or frost.

2.4 Pressure Test All PSHE units have been tested prior to dispatch as follows : a) all plate packs – the leaking test (air under water) b) whole unit – pressure test (hydrostatic pressure test) If it is required to perform a pressure test prior to start-up, the test. Pressure is shown on the technical data- sheet and on the nameplate.

NOTE The plate pack has to be assembled into the shell before the pressure test can be performed. 2.5 Brackets For consideration when using Vahterus standard end plates, and brackets. Vahterus standard brackets are only designed to accept the exchanger weight. They do not incorporate specific requirements such as wind loads or seismic considerations.

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3.1 Design conditions

The design pressures and temperatures are marked on the name plate and also on the technical data sheet.

Never exceed the design pressures or temperatures which are stated on the name plate.

3.2 Fluids The materials of construction are based on a data provided by the customer. If the fluids and temperatures differ from those specified in the data sheet, it is the customer’s responsibility to ensure that there is no corrosion risk. You can also contact Vahterus for material and flow director material validation ; otherwise it is the customer´s responsibility.

If the material is AISI 316/AISI 316L/ 1.4404, the fluids chloride content must be below 50 ppm and the pH must be greater than 7.

3.3 Flow rates Operating flow rates should be maintained as close as possible to the design flow rates. Significantly lower flow-rates, especially on the process side, may result in unpredictable thermal performance as well as premature fouling due to sedimentation.

3. Allowed operations conditions

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4. Principle of function and start-up of precess4.1 Principle of the heat exchangers The function of the heat exchanger is to transfer heat from the primary to secondary flow through circular corrugated heat transfer plates.

The construction is such that primary and secondary channels alternate throughout the plate pack. The flow can be arranged as counter-current, co-current or cross-flow as desired.

Construction of the Vahterus plate and shell heat exchanger : A plate and shell heat exchanger consists of circular plates welded into a pack which are then inserted into a pressure vessel.

One medium enters and leaves through plate ports aligned with end cover connections. This is known as the plate side flow.

The other medium enters through connections on the shell and is directed to individual channels by means of peripheral elastomeric flow directors and exits in a similar manner at a shell connection. This is known as the shell side flow.

The construction can be either fully welded or in certain cases, openable. This is where we have a single pass operation, with a removable end cover so that the plate pack can be withdrawn for inspection.

Below we outline the various unit operations of the PSHE:

4.1.1 Liquid - Liquid

In liquid / liquid applications, the hot and cold sides can be applied to either side of the exchanger, depending on the nature of the installation. Usually the Hot side would be on the plate side, but it can equally be processed on the shell side. The same is conversely true for the cold stream. Hot and Cold streams will be clearly marked on all drawings provided.

1-pass 1, 3-passes

2, 4-passes

1-pass, openable

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4.1.2 Condenser

In condensing applications, the condensing stream is usually processed on the shell side, with the service (cold) side applied to the plate side. Shell side (condensing) flow enters the exchanger at the top of the shell and exits at the bottom. Plate side flow is run counter-current, to the shell side flow

4.1.3 DX-Evaporator

Hot in

Hot out

Cold out

Cold in

1-pass

Hot outHot out

Cold in

Cold out

Hot in Hot in

Cold out

Cold in

1, 3-passes 2, 4-passes/plate side 1-pass/shell side

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4.1.4 Evaporator

4.1.5 Separator system

Cold out

Hot out

Hot in

Cold in

1-pass eccentric

Max. liquid level

Max. liquid level

The heat exchanger system is the same as 4.1.4, with the addition of the droplet separator/surge drum with recirculation pipe.

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4.2 Start-up Before start-up please check the following :

The pipe connections comply with the drawings and are properly fastened. • The drain valves are closed• The expansion joints of the secondary side are connected to the expansion tank, if the heat exchanger •

is provided with these.There are no potential sources of water hammer, steam hammer or sudden pressure changes. •

Start the flow of the cold side first, then start and gradually increase the flow of the hot side. The maximum temperature rise should be limited to 55°C per hour. In the flooded evaporator start the hot side first. If the used liquid has high viscosity, then start

the hot side first.

To start- up the heat exchanger follow steps a) to f) for the cold side first. Then repeat for the hot side.

a) Close the inlet side valve. b) Open totally the shut-off valve on the outlet side. c) Open the vent valve, if the heat exchanger is provided with this, otherwise vent from nearest point in

the pipeline to the heat exchanger. d) Start the pump. e) Slowly open the feed valve. See notes for start-up & shut-down. f) Close the vent valve when all air has been removed.

If the heat exchanger operates in accordance with the specification, it can be taken into continuous use.

Openable modeAnd if re-starting after shut down check also• the bolting, and retighten if necessary.

4.3 Shut downIf heat exchanger is to be shut down follow steps a) to d) below for the hot side first, then repeat theprocedure for the cold side.

a) Slowly close the feed valves. b) Switch off the pumps. c) Close the valves at the outlet connections. d) Drain and vent the heat exchanger.

Gradually decrease the flow of the hot side until stops. Then shut down the cold side flow

Notes : Valves must be set to open gradually. Sudden opening and closing of the valves will subject

the exchanger to thermal shock and may cause material fatigue.

In steam applications, never leave the steam on with the liquid side turned off. Turn the steam OFF first and ON last.

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5. Cleaning of the heat exchanger 5.1 General

The requirement for and regularity of cleaning the heat exchanger depends on the type of media processed. If there is a risk of fouling the performance of the unit should be monitored by measuring any temperatures and pressures losses. When pressure losses reach an unacceptable level or temperature indicate poor heat transfer, the heat exchanger should be cleaned.

Note In most cases loose debris gathered on the surface of the plates can be removed by back washing with warm water. Clean water is flushed at high velocity on one side and/or both sides in a direction opposite to the normal operation direction. The valves in the connection pipes must be closed and the drain valves opened. Any dirty water / effluent must be disposed of in accordance with local regulations.

5.2 Guidelines for cleaning

If scale cannot be removed from the heat exchanger by washing; soda solution, 2 % caustic and/or 0,5 % sulphamic acid (NOT sulphuric acid) may be used up to 60 °C. Phosphoric acid at 5% concentration can also be employed.

Type of fouling Suggested cleanersCalcium Sulphate, Silicates Citric, Nitric, Phosphoric or Sulphamic AcidCalcium Carbonate 10 % Nitric Acid Alumina, Metal Oxides, Silt Citric, Nitric, Phosphoric or Sulphamic AcidBarnacles, Mussels, Seaweed wood chips Back Flush per cleaning-in-place procedure Biological Growth Sodium carbonate or sodium hydroxide

WARNINGS!!

If the shell materials is carbon steel, do not use nitric acid for cleaning the shell side. Also reduce the strength of sulphamic acid to 2 %.

Sulphamic acid hydrolyses with the temperature and time therefore only use freshly made solutions.

After soda, acid or detergent treatment, the plates must be absolutely rinsed carefully and thoroughly with clean water.

Never use hydrochloric acid with stainless steel plates, even in low concentrations.

Never use phosphoric or sulphamic acid for cleaning titanium plates, even at low concentrations.

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5.3 Openable model When removing the plate pack please follow these instructions in order to avoid damaging the plate pack.

5.3.1 Preliminary actions Before opening the unit all pipe connections must be opened and the unit must be drained from shell and plate sides. It is recommended to move the unit to separate area where there is enough empty space to carry out any required maintenance. If there is no possibility to move the unit, please ensure that in front of the unit there is enough space for opening (minimum requirements for space is total length of unit). Then it is only necessary to open and separate the plate side connections.

5.3.2 Opening the unit and removing the plate pack After removing all bolts from the flange and before lifting the plate pack, the guiding bars must be installed (four / six ea.) to the bolt holes. Make a mark that ensure that the plate pack assembly will return back to the shell in the same position!!!

Pull the plate pack carefully out from shell using the lifting lugs (located on the flat face) on the blind flange.

Alternative 1 (Recommended) When there is a possibility to remove the unit to a large room, it is recommended to turn the unit so that the plate side connections are upwards (plate pack vertically).

Please ensure that the exchanger is supported properly, and be sure that it remains stable and upright during removing.

See drawing 1.

Guiding barGuiding bar

Drawing 1

Pull

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Alternative 2 When pulling the pack out, try to maintain the horizontal level of the plate pack by using necessary lifting force via the lifting lug on top of blind flange (see drawing 2 below). When the plate pack is almost out of the shell, place two wooden blocks under the plate pack to protect the flow directors. Lifting straps should be placed as shown in drawing 2.

Drawing 2

5.3.3 Mounting the plate pack Before reinstalling the plate pack, the flow directors must be checked and repaired if necessary. Also the flow director rubbers also should be checked. If they need replacing, contact Vahterus Oy.

Please also change the flange gasket; the type of gasket can be found in the technical data sheet.

To ensure straight and safe reinstallation, you have to remember to put the guiding bars back to their places and check the correct position of plate pack.

Also, please lubricate the flow director rubbers prior to assembly, with, for example vegetable oil, to assist with the re-installation of the plate pack.

While the plate pack is mounted into the shell, the position of the flow directors must be checked.

Pull

SupportGuiding bars

Wood block

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5.3.4 Bolt/stud tightening pattern When tightening up bolts on a flange, never use an impact tool. It is vitally important to control accurately the amount of force: always use a torque wrench or other controlled-tensioning devices (calibrated).

The sequence in which bolts are tightened has a substantial bearing upon the distribution of the assembly pressure on the gasket. Improper bolting may move the flange out of alignment. A gasket will usually allow for a small amount of distortion of this kind.

Always run the nuts or bolts down by hand. This gives an indication that the threads are in satisfactory condition (if the nuts will not run down by hand, then there is probably some thread defect – check again and, if necessary, replace defective parts).

Now torque the joint using a minimum of 5 torquing passes, using a cross bolting sequence for each pass, as shown. The following procedure is recommended :

Pass 1 – Tighten nuts loosely by hand in the first instance, acc. to the cross bolt tightening pattern, then hand-tighten evenly

Pass 2 – Using a torque wrench, torque max. of 30% of the full torque first time around, acc. to the cross bolt tightening pattern. Check that the flange is bearing uniformly on the gasket.

Pass 3 – Torque to a max. of 60% of the full torque, acc. to the cross bolt tightening pattern

Pass 4 – Final pass at full torque, in a clockwise direction on adjacent fasteners

In table below are bolt and nuts pretension values:

Size 8.8 Torque (N m)M20 425M24 730M30 1450M36 2600

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6. Spare Openable single pass model

There may be an infrequent need to replace flow directors arising from potential accidental damage. •

It is possible to replace the plate pack. •

Flange gasket •

These are also obtainable from Vahterus by providing the drawing and serial numbers for the unit.

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7. Service / Trouble shooting If the heat exchange is not working or sufficiently performing after start-up or during the operation, check the following

Problems Causes First action Corrections Obs!Capacity not sufficient

Pipe connections connected wrong

PressurePressure differenceTemperatureLiquid flow

Check flow directions of connections. Do they comply with the design/drawing?Check bolt: pressure and temperatures on both side; and them ok? Measure flowrates and pressure difference. Compare these values to the PSHE's thermotechnical data sheet.

Check that pump operates perfectly.

Change the piping.

Correct position of the valves. Adjust control valve.

Change pump.

Contact Vahterus and inform measurements: pressures, pressure difference, temperatures and flowrates.

External leakage at cover plate (openable model)

Flange gasket failure.

Visually locate the origin of the leak.

Retighten bolting. If re tightening the bolting doesn't stop the leak, remove cover plate and change gasket

Secure from Technical data sheet the type of gasket. See tightening torque in section 5.1 of this manual.

Internal leak (cross contamination)

Plate cracked due to water hammer or thermal shock.

Hole in plate due to corrosion.

Pressure shock

Mechanical wearing

Check that plate side packs liquid really appears in shell side outlet pipe. Close plate or shell side valves and follow to see if the pressure sensors value decreases. Check the process data, if available.

Pressurize shell and check leak. Localize leak e.g. with colorant.

Contact Vahterus.

Contact Vahterus.

Contact Vahterus.

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Problems Causes First action Corrections Obs!Extremely low thermal performance and very high pressure losses

Shell or plate side channels clogged with accumu lation of debris or scale from process.

Filter plugged.

Valve / process control doesn´t work properly.

Measure pressure lossesacross each side of the exchanger as accurately as possible to make sure the problem isn´t caused somewhere else in the system.

Open filter and check condition.

Check that they are open and work properly.

Clean the exchanger as required.See section 6 in this manual.

Clean / change the filter.

Do necessary actions e.g. open, adjust or change.

Do scheduled maintenance/check work plan.

Gradual decline of heat transfer performance.

Slow build up of fouling on the plate and/or shell side.

Remove the platepack(openable model) and examinethe heat transfer surfaces.Welded models can be checked by endoscope, if it's possible.If the shell side is clean, fouling of the plate side is responsible for the heat transfer decline.

Clean the exchanger as required. See section 6 in this manual.Replace gasket and reassemble the plate pack (openable model).

Do scheduled maintenance/check work plan.

Extremely low thermal performance and low pressure drop.

Flow director damaged by pressure shock or unsuitable process fluid.

Check the information on the name plate: are the temperature, liquids as per the name plate? Check the process data.

Contact Vahterus.

If, after this checking the heating / cooling capacity and/or pressure losses have reached a unacceptable level, contact your Vahterus representative.

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Measurement

7.1 Claim report

If there is a need to make a claim, you can ask for a claim report form on our e-mail sales@vahtus.com or from Sales Manual.

In the claim report it is good if you can provide as much information as possible, particularly the following points : - General data (Serial number) - Design and operating data - Type of problem and observation - Status process

After fullfilling this please contact your Vahterus representative

7.2 Measures for replacement

If there is a requirement to replace a plate pack please take measurement from three different places inside the shell - see principle drawing below.

IM-R01-386AB Issue 1 01.09