Page 1 of 23

Temperature Control Manual Version 0.1

Date: 1/02/2007
Heat Exchanger Prepared By: Justin Day
Engineering Department

Temperature Control Manual

Heat Exchangers

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Temperature Control Manual Version 0.1

Date: 1/02/2007
Heat Exchanger Prepared By: Justin Day
Engineering Department

TABLE OF CONTENTS

Section Page

1 INTRODUCTION................................................................................................................ 3
1.1 Description........................................................................................................................ 3
1.2 Equipment......................................................................................................................... 3
1.2.1 Identification of the Heat Exchanger ........................................................................... 3
1.2.2 Ultra Flex (GX) Plates ................................................................................................. 4
1.2.3 Conventional (GC and GL) Plates............................................................................... 5
1.2.4 Wide Gap (GF) Plates.................................................................................................. 5
1.2.5 Semi Welded (GW) Plates........................................................................................... 6
1.2.6 Plate Identification....................................................................................................... 6
2 TECHNICAL DATA ........................................................................................................... 7
3 INSTALLATION, OPERATION AND MAINTENANCE (IOM) ............................... 13
3.1 Introduction..................................................................................................................... 13
3.2 Installation ...................................................................................................................... 13
3.2.1 Foundation ................................................................................................................. 13
3.2.2 Inlet and Outlet Hoses ............................................................................................... 13
3.3 Commissioning ............................................................................................................... 13
3.3.1 Initial Start-up............................................................................................................ 13
3.3.2 Start-up ...................................................................................................................... 14
3.3 Operation ........................................................................................................................ 14
3.3.1 Principal of Operation ............................................................................................... 14
3.3.2 Pumps ........................................................................................................................ 15
3.3.3 Venting ...................................................................................................................... 15
3.4 Shut Down ...................................................................................................................... 15
3.4.1 Storage Procedures .................................................................................................... 15
3.4.2 Gasket Storage Procedure.......................................................................................... 16
3.5 Maintenance.................................................................................................................... 17
3.5.1 Lubrication................................................................................................................. 17
3.5.2 Opening The Heat Exchanger.................................................................................... 18
3.5.3 Removing the Plates .................................................................................................. 18
3.5.4 Cleaning the Plates .................................................................................................... 19
3.5.5 Adjusting the Gaskets ................................................................................................ 20
3.5.5 Gluing the Gasket ...................................................................................................... 20
3.5.6 Assembly ................................................................................................................... 20
3.5.6 Tightening the PHE ................................................................................................... 21
3.5.7 Cleaning-In-Place (CIP) ............................................................................................ 22

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Temperature Control Manual Version 0.1

Date: 1/02/2007
Heat Exchanger Prepared By: Justin Day
Engineering Department

1 INTRODUCTION

1.1 Description

Aggreko’s Plate Heat Exchanger (PHE) consists of Fixed and Moving Cover Plates,
Carrying and Guiding Bars, End Support, Corrugated and Gasketed Heat Transfer Plates,
Tightening Bolts/Nuts, and Connection Ports. The corrugated plates are held in between
the fixed and moveable cover and are compressed by the tightening bolts. Optional
protection shrouds are available on request from Tranter. The heat exchanger’s
construction enables it to be easily opened for inspection, cleaning and extension.

Plates are manufactured in standard sizes in virtually any material that can be cold
worked. The size, number and arrangement of the plates are contingent upon the duty
performed. Accordingly, the units are custom designed for each application.

Elastomer gaskets are glued in the gasket groove around the heat transfer surface and the
portholes. The gaskets are doubled around the portholes to prevent leakage between the
media. In the event of gasket failure the medium runs straight out of the exchanger. When
the unit is tightened, the gasket seals the structure and in conjunction with the portholes,
allows fluids to flow in alternate channels and almost always flow counter-currently. The
thin fluid interspace coupled with the corrugated plate design induces turbulence that
produces extremely high heat transfer coefficients.

1.2 Equipment

1.2.1 Identification of the Heat Exchanger

Each of Aggreko’s PHE’s are provided with a machine plate attached to the fixed cover.
This plate contains information, which, once the serial number is passed to Tranter
(manufacture of Aggreko’s PHE’s), will enable them to machine plates and other
components of the PHE to match. The details that are located on the plate, is as follows:
a. Plate heat exchanger type
b. Serial number
c. Year of construction
d. Permitted working pressure (bar)
e. Permitted working temperature (oC)
f. Channel arrangement
g. Volume (litres)
h. Connection location
i. Test pressure (bar)

Weight empty/full (kg)ll moving components are enclosed in a prefabricated, sheet metal
enclosure that is acoustically lined to ensure low level noise.

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Temperature Control Manual Version 0.1

Date: 1/02/2007
Heat Exchanger Prepared By: Justin Day
Engineering Department

1.2.2 Ultra Flex (GX) Plates

With the gasket groove in the plate’s neutral plane the GX Plate can be rotated about its
x-axis as well as its y-axis, thus flow channels are formed with differing thermal
characteristics.

Every plate size is available with two different angle combinations thus forming six
different flow channels for every plate size. Ultra Flex system is available in different
plate sizes from 0.06m2 to 3.3m2..

The GX series of plates are based on a diagonal flow pattern and have a gasket groove in
the neutral plane. Parallel flow pattern can be designed at special request through Tranter.

The heat transfer plates are made with two different arrowheads angles: one obtuse high
theta plate (high resistance to flow), and one acute low theta plate (low resistance to
flow).

GX plates are identified by means of different embossed code letters. These letters can be
found at the extreme corners of each plate. When a plate pack has been correctly installed
the embossed letters at the TOP RIGHT CORNER (when viewed from the outer face of
the fixed cover plate) should correspond with the plate assembly code.

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Temperature Control Manual Version 0.1

Date: 1/02/2007
Heat Exchanger Prepared By: Justin Day
Engineering Department

1.2.3 Conventional (GC and GL) Plates

Normal herringbone (chevron) pattern is ideally suited for handling aqueous solutions.
The heat transfer plates are made with two different arrowhead angles: one obtuse having
high theta plate (high resistance to flow), and one acute giving a low theta plate (low
resistance to flow).

The GC series of plates is based on a parallel flow pattern and has a gasket groove in the
bottom plane. Each plate has one gasket.

NOTE: GL plates have a conventional herringbone pattern like GC plates but the gasket
groove is in the plate’s bottom plane. GL plates are available in both diagonal and parallel
execution.

1.2.4 Wide Gap (GF) Plates

These plates are used for strongly contaminated media. Utilised for fluids containing solid
particulates or viscous products with a wide gap in flow requirements, up to 12mm.

The Wide Gap plates can be arranged in two different configurations; Wide/Narrow when
one of the fluids contains large particles that require wide gap channels or
Medium/Medium when both fluids require additional flow area. Both configurations are
accomplished with single plate geometry.

The GF series of plates is based on a parallel flow pattern and have gasket groove in the
neutral plane.

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Temperature Control Manual Version 0.1

Date: 1/02/2007
Heat Exchanger Prepared By: Justin Day
Engineering Department

1.2.5 Semi Welded (GW) Plates

The semi welded PHE’s consist of a number of plate pair (also referred to as elements)
and a frame assembly. Plate pairs are laser welded together to form a sealed channel or
element. These are utilised for ammonia or very aggressive fluids.

A plate pack normally consists of a start plate (single C or F plate) + elements + end
plates (single D plate). The GF series of plates is based on a parallel flow pattern.

GW-81: Two asymmetric C plates welded together with the narrow channel inside the
element. The element is marked in the upper corner with the letter O. Standard element
for ammonia application (Direct Expansion).

GW-83: Two symmetric F plates welded together. The element is marked in the upper
corner with the letter S. Standard element for ammonia application (Thermosiphon
system).

1.2.6 Plate Identification

A six-digit number is stamped into the long edge of each plate when it is pressed. This
number is a code to identify the material on the plate.

The first digit – Year of Manufacture;

last figure in the year 1998.

The second digit – See chart

The last four digits – Running number

for each charge.

Example:

561031 – Titanium Grade 1,

manufactured in 2005.

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Temperature Control Manual Version 0.1

Date: 1/02/2007
Heat Exchanger Prepared By: Justin Day
Engineering Department

2 TECHNICAL DATA

aggreko
Prepared by: Adam Hentschel Date: 9/10/2001 Revision: A Page 7 of 23
Discipline: Heat exchanger Document number

Section:
HX 500 au7.1

1. INTRODUCTION

Aggreko Heat Exchangers are used for separation of aggressive liquids from a chilled fluid
circuit.
Units come as nominal 20l/s flow and can be paralleled for a larger requirement.
We recommend that for all applications a model be requested from the Aggreko technical
department. Heat exchangers can also be used to cool gases, heat liquids and deliver 2º water.
Stainless steel quick camlock fluid connections ensure easy and leakage free connections. The
Heat exchangers are mounted to a heavy galvanised frame.

2. KEY – DATA

Type GX-42
Nominal Flow 20kg/sec
Nominal heat exchange 500kW
Dimensions
Length 1100 mm
Width 1100 mm
Height 1920 mm
Weight 669 kg

3. LAYOUT

4. TECHNICAL SPECIFICATIONS

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Temperature Control Manual Version 0.1

Date: 1/02/2007
Heat Exchanger Prepared By: Justin Day
Engineering Department

ITEM UNITS VALUE

Performance Data Example
Fluid name water water
Reference temperature °C 12.18 7.82
Viscosity cP 1.23 1.40
Viscosity wall cP 1.30 1.32
Density kg/m³ 999.5 1000
Heat capacity kJ/kg,°C 4.20 4.21
Thermal conductivity W/m,°C 0.591 0.583
Side 1 Side 2
Inlet temperature °C 15 5
Outlet temperature °C 9.35 10.64
Mass flow rate kg/s 30.00 30.00
Number of heat transfer units NTU 1.30 1.29
Heat load kW 711.14
Total heat transfer area m² 25.08
Heat flux kW/m² 28.37
Mean temperature difference C° 4.36
Overall H.T.C. W/m²,C 6507
Pressure drop - total kPa 100
- in ports kPa 6
Materials
Plates 316 Stainless
End Plates Cast Iron
Fittings 316 Stainless
Physical Properties
Connection diameter mm 105
Number of channels # OLS+29LD
Number of Plates # 59
Maximum operating Pressure bar 13
Minimum / Maximum Fluid Temperature C° -25 to 99°C
Length mm 1100
Width mm 1100
Height mm 1920
Weight kg 669
NOTE: We recommend that for all applications a model be requested from the
Aggreko technical department

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Temperature Control Manual Version 0.1

Date: 1/02/2007
Heat Exchanger Prepared By: Justin Day
Engineering Department

aggreko
Prepared by: Adam Hentschel Date: 9/10/2001 Revision: B
Revised by: Page 9 of 23
Jason Dignam 24/08/2005
Discipline: Heat exchanger Document number

Section:
HX500 HP au7.2

1. INTRODUCTION

Aggreko Heat Exchangers are used for separation of aggressive liquids from a chilled fluid
circuit.
Units come as nominal 18l/s flow and can be paralleled for a larger requirement.
We recommend that for all applications a model be requested from the Aggreko technical
department. Heat exchangers can also be used to cool gases, heat liquids and deliver 2ºC
water.
Stainless steel quick camlock fluid connections ensure easy and leakage free connections. The
Heat exchangers are mounted to a heavy galvanised frame.

2. KEY – DATA

Type B-57
Nominal Flow 75 kg/sec
Nominal heat exchange 528 kW
Dimensions
Length 1495 mm
Width 805 mm
Height 1530 mm
Weight 600 kg

3. LAYOUT

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Temperature Control Manual Version 0.1

Date: 1/02/2007
Heat Exchanger Prepared By: Justin Day
Engineering Department

4. TECHNICAL SPECIFICATIONS

ITEM UNITS VALUE

Performance Data Example
Fluid name Water Water
Reference temperature °C 12.8 7.82
Viscosity cP 1.23 1.4
Viscosity wall cP 1.3 1.32
Density kg/m³ 999.5 1000
Heat capacity kJ/kg,°C 4.2 4.21
Thermal conductivity W/m,°C 0.591 0.583
Side 1 Side 2
Inlet temperature °C 30 6
Outlet temperature °C 22.95 13
Flow rate kg/s 75 75
Heat load kW 528.2
Total heat transfer area m² 17
Mean temperature difference C° 16.98
Overall H.T.C. W/m²,C 1830
Pressure drop - total kPa 217
Materials
Plates AISI 316
End Plates Carbon Steel
Fittings AISI 316
Physical Properties
Connection diameter mm 54
Number of channels 51 52
Number of Plates # 104
Maximum operating Pressure bar 27
Minimum / Maximum Fluid Temperature C° -20 / 155
Length 1495mm
Width 805mm
Height 1530mm
Weight 600kg
NOTE: We recommend that for all applications a model be requested from the Aggreko
technical department.
Confidentiality Notice: This document and any accompanying documents contain
information that is private and protected.

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Temperature Control Manual Version 0.1

Date: 1/02/2007
Heat Exchanger Prepared By: Justin Day
Engineering Department

aggreko
Prepared by: Date: Revision:
Revised by:
Jason Dignam 24.08.05 A Page 11 of 23

Discipline: Heat exchanger Document number

Section:
HX 1000 au7.2
1. INTRODUCTION

Aggreko HX 1000 Heat Exchangers are used for efficient transfer of energy (heat) between a
hot and a cold media. Heat Exchangers are also providing a safe solution for separation of the
hot and cold circuits in heat recovery applications or close circuit heat transfer applications.
They can be used to cool gases or aggressive or corrosive liquids.
Units are designed for a nominal flow of 40 l/s and can be connected in parallel to
accommodate larger flow rates.
Stainless steel quick connect camlock fluid connections ensure easy and leakage free
installation. The Heat Exchangers are mounted to a heavy duty galvanized frame.
NOTES: If high concentrations of chloride ions (over 200 to 300 ppm) are present in at least one of the
heat exchanger circuits, contact the technical department for further information.
For all non standard applications (other media than clean fresh water, flow rates under 40 l/s, pressure
above 15 bars or temperatures above 120 *C, etc.) a Heat Exchanger performance and/or material
compatibility analyses must be conducted"

2. KEY – DATA

Type GX-51
Nominal Flow 40kg/sec
Nominal heat exchange 1031kW
Dimensions
Length 1700 mm
Width 1100 mm
Height 2000 mm
Weight 1642 kg
3. LAYOUT

4. TECHNICAL SPECIFICATIONS

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Temperature Control Manual Version 0.1

Date: 1/02/2007
Heat Exchanger Prepared By: Justin Day
Engineering Department

ITEM UNITS VALUE

Performance Data Example
Fluid name water water
Reference temperature °C 14.92 8.07
Viscosity cP 1.14 1.38
Viscosity wall cP 1.23 1.26
Density kg/m³ 999.1 999.9
Heat capacity kJ/kg,°C 4.19 4.20
Thermal conductivity W/m,°C 0.589 0.576
Side 1 Side 2
Inlet temperature °C 18.00 5
Outlet temperature °C 11.83 11.14
Mass flow rate kg/s 40.00 40.00
Heat Flux kW/m² 19.33
Heat load kW 1031
Total heat transfer area m² 53.35
Mean temperature difference C° 4.20
Overall H.T.C. W/m²,C 4607
Pressure drop – total kPa 32
-- in ports kPa 2

Materials
Plates 316 Stainless
End Plates Carbon Steel
Fittings 316 Stainless
Physical Properties
Connection diameter mm 105
Number of channels # OLS+49LD
Number of Plates # 99
Maximum operating Pressure bar 21
Minimum / Maximum Fluid Temperature C° -10 to 99°C
Length mm 1700
Width mm 1100
Height mm 2000
Weight kg 1642
NOTE: We recommend that for all applications a model be requested from the
Aggreko technical department

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Temperature Control Manual Version 0.1

Date: 1/02/2007
Heat Exchanger Prepared By: Justin Day
Engineering Department

3 INSTALLATION, OPERATION AND MAINTENANCE (IOM)

3.1 Introduction

To gain the maximum benefits of Aggreko’s PHE’s, care is to be taken when carrying out
installation.

3.2 Installation

It is necessary to provide enough clearance around the PHE. This facilitates access to the
PHE and permits for necessary service tasks. The heat exchangers must be installed with
clearance on both sides

3.2.1 Foundation

A solid foundation is required for the positioning of the unit. It may be necessary to place
the PHE on a drip tray or drainage box.

3.2.2 Inlet and Outlet Hoses

All pipe work must be free from leaks and be as short as possible. As much air must be
expelled from this system as possible to avoid water hammer.

CAUTION: Water Hammer must be avoided, as the rubber gaskets may be displaced and
cause leakage.

3.3 Commissioning

3.3.1 Initial Start-up

a. Check that the operating data does not exceed that given on the PHE machined plate.
b. Check that all tightening bolts are properly tightened.
c. Check that all connection pipes are secured.
d. Check that the A-dimension is correct.

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Engineering Department

3.3.2 Start-up
a. Close the supply valve between the PHE and the pump.
b. Fully open the valve at the outlet connector (if fitted).
c. Open the vent valves.
d. Start the pump.
e. Slowly open the supply valve to prevent any pressure surges.
f. When there is no more air present in the system, close the vent valves on the PHE.
g. Follow steps 1 – 6 for the second side.

3.3 Operation

Always check applicable Site and Statutory Safety Regulations before you start. Make
sure that the PHE is not under pressure, cold (max 40oC) and empty before starting work.

Each PHE is supplied with the thermal design data sheet, giving details of the operating
parameters, limits, capacity etc.

The PHE is often one part of a complete process system, sometimes with advance
automatic controls. Always check applicable instructions for the whole process system
before you start.

3.3.1 Principal of Operation

A series of pressed plates with portholes, form the plate pack of flow channels. The heat
exchange media flow through these plates in alternate direction/channels.

Usually single-pass plate heat exchangers are used. They are distinguished by the 100
percent counter-flow of the two media. All of the feed and discharge pipes are connected
to the fixed cover plate. This is a particular maintenance friendly installation.

Close temperature differences between the media may demand multi-pass PHE’s. The
connection pipes are then attached both to the fixed and movable cover plates.

Single Pass Unit Double Pass Unit

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Temperature Control Manual Version 0.1

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Heat Exchanger Prepared By: Justin Day
Engineering Department

3.3.2 Pumps

Pumps that feed the PHE must be provided with regulating valves. If the pumps can
deliver a higher pressure than the rated pressure for the heat exchanger, safety valves
must be installed. The pumps must not induce air.

3.3.3 Venting

The PHE must be vented correctly. Remaining air can cause air locks and serious
scorching of the plates, reducing the heat transfer capacity and increasing the risk of
corrosion.

3.4 Shut Down

For short periods of time, proceed as follows;

a. Slowly close the supply valves, starting with the supply line with the higher
pressure.
b. Shutdown the pumps.
c. Close the valve in the outlet pipes (if fitted).

For longer periods of downtime and especially when there is a risk of freezing or if the
medium is aggressive, the PHE must be emptied or cleaned.

While the unit is not in use, ease the tension on the tightening bolts so that the plates just
lie against each other, but close enough to prevent any dirt entering between them. The
tightening bolts should be greased.

3.4.1 Storage Procedures

When a PHE is to be placed in storage for an extended period of time, the following must
be adhered to:
a. Prior to draining, remove any shroud and let the unit cool to ambient temperature,
then drain completely. Units with plate packs arranged in one pass (all connections
to the fixed cover plate) are self draining. Simply vent at the upper nozzle location
and drain from the lower nozzle for each side individually. A two pass unit is also
self draining, provided all nozzles are at the lower elevations (S2/S3/M2/M3).
Other units maybe self draining if they have been fitted with separate drain and
vent connections. Units that are not self-draining must have the plate pack
completely loosened to drain all the liquids. Before opening the plate-pack, wipe
off the exterior surfaces with water to make sure no fluids or debris fall into the
plate pack.
b. Open the plate pack and thoroughly clean the unit internally and externally. Dry
the unit. (Blowing warm air at approx. 60oC on all areas is a good method).
c. Install blind flanges with gaskets on all inlets and outlets. Plug all other openings.
d. Coat all unpainted carbon steel components with light grease, SAE 30 oil or other
rust inhibiting products.
e. Coat all bolt threads with light grease.

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Engineering Department

f. To minimise gasket compression, the plate pack length dimension needs to be

adjusted. As a guideline, the units tightening dimension should be increased by a
factor 1.2 (e.g. if the A-dimension is 500mm, the bolts should be slackened to a
new dimension of 600mm).
g. Protect the unit from direct sunlight, intense heat radiation or ultra violet light by
covering the unit with an opaque, reflecting type plastic film or similar material.
Make sure air is allowed to circulate around the unit preventing condensation and
negative effects.
h. It is preferable to house the unit indoors, well protected from the weather. The
temperature in the storage area should ideally be 20oC with a maximum RH of
70%. Avoid storing the unit in an area where the temperature can fall below 0oC.
i. All potential sources of ozone, such as operating electric motors, or welding
equipment, should be removed from the storage area to prevent ozone attacks
against the gaskets.

3.4.2 Gasket Storage Procedure

Rubber gaskets stored under unsuitable conditions leads to physical properties changes
and can result in hardness change, permanent deformation, cracks or other surface
damage. If the rubber parts are handled and stored correctly they will maintain their
properties for longer period of time.

A temperature of >20oC will see a gradual deterioration of the physical properties. A

10oC increase can result in twice the ageing rate. Rubber gaskets that have been
subjected to low temperature during freight or storage may stiffen from the cold and
should be warmed to approx. 20oC for a period of time. Precautions to avoid condensation
on the gaskets should be taken.

Rubber articles should be protected from light, especially direct sunlight and artificial
light with high UV intensity.

Ozone is a danger to the gaskets. Electrical motors or other machines that produce
sparks or other electrical discharges which can produce ozone must not be present in the
storage room.

Rubber gaskets should be stored so that they are deformed as little as possible.
Mechanical forces within the rubber material can speed up the ageing rate and is the basic
mechanism behind the formation of ozone cracks, especially in NBR rubbers.

If the above recommendations are followed, the storage time will be at least:

Remember to use gaskets on a first in, first out basis.

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Temperature Control Manual Version 0.1

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Engineering Department

3.5 Maintenance

Unscheduled shutdowns are very expensive and quite unnecessary. Fouling causes
decreased performance and gasket ageing. The heat exchanger should be emptied and
cleaned on a regular basis so that the condition of the heat transfer plates and the gaskets
can be checked. Each application is unique, making it very hard to predict service
intervals.

Gaskets do age. If they are replaced in time, you Plates get dirty. The coating affects heat
avoid both leakage and any resulting damage. Transfer and reduces performance.

3.5.1 Lubrication

The thread of the tightening bolt must be kept lubricated with molybdenum disulphide or
equivalent, particularly on the section on the thread used for opening and closing the
equipment.

To improve their sliding ability, the following components should be treated with an acid
free grease
a. Sectional rails and beam surfaces to which the plates are attached and which they
are slid.
b. Pressure surfaces between tightening nut and retaining ring.
c. The bearings of the carrier roller on the movable cover plate.

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Temperature Control Manual Version 0.1

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Engineering Department

3.5.2 Opening The Heat Exchanger

No special tools are required. A ratchet spanner is all that is needed for maintenance and
repair.
a. Shutdown should take place slowly. Make sure the unit is not under pressure and is
empty before starting work.
b. Cool the heat exchanger. If possible allow the heat exchanger to stand and cool
overnight.
c. Disconnect any connection to the moveable cover.
d. Clean the thread of the tightening bolt.
e. Apply a thin film of oil to the thread.
f. We advise painting a diagonal line cross the plate pack to ensure that the plates are
reassembled in the right order.
g. Note the current A dimension.
h. Remove Bolts 1.
j. Slacken nuts 2, 3 and 4 alternatively so that the movable cover can move parallel
with the frame plate.
k. Remove bolts 3 and 4.
l. Slacken nuts 2 alternatively.

3.5.3 Removing the Plates

When handling the plates, gloves are to be worn at all times due to the sharpness of the
edges.

If two or more plates have stuck together they must be separated carefully so the gaskets
are kept on the correct plate. The plates support each other in pairs. If a plate has been
damaged beyond repair or replacement, the adjacent plate must also be taken out of the
PHE. If the number of plates is changed, so is the A-dimension. Special plates, such as
the first and last plates and turning plates in multi-pass PHE, must be replaced with
identical plates

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Temperature Control Manual Version 0.1

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Heat Exchanger Prepared By: Justin Day
Engineering Department

3.5.4 Cleaning the Plates

Fouling of the PHE is often caused by low flow velocity through the heat exchanger.
Where the possibility exists to increase the flow this should be tried if the heat exchanger
shows signs of reduced capacity or increased pressure drop. Severe fouling requires
opening and cleaning the heat exchanger.
a. The heat exchanger is opened IAW (in accordance with) section 3-4-2.
b. Steel wool or brushes of carbon steel must not be used on titanium plates.
c. In the first step, the heat transfer surface is cleaned by rinsing with a powerful jet
of water and scrubbing with a nylon or similar brush.
d. Take care not to damage the gaskets.
e. The gaskets must be dried with a clean cloth. Solid particles adhering to the gaskets
cause damage and result in leakage when the unit is placed back in operation.
f. The lower portion of each plate as hung in the unit should be inspected carefully
and cleaned appropriately as this is the primary area where residual solid material
will accumulate.

Do not use chlorine or chlorinated water to clean stainless steel or Nickel alloys. Chlorine
is commonly used to inhibit bacterial growth in cooling water systems. Chlorine and
chlorinated water can rapidly attack the above mentioned materials. For any applications
where chlorination must be used with non-titanium equipment, Head Office is to be
notified.

The following are some guidelines for cleaning the plates of the PHE
a. Do not use hydrochloric acids or water containing in excess of 300ppm chlorides,
with stainless steel.
b. Do not use phosphoric or sulfamic acid for cleaning titanium plates.
c. Limit cleaning solution concentration to 4% strength, with temperature not
exceeding 60oC unless otherwise specified.

CAUTION: Sodium hydroxide and concentrated Nitric acid can seriously harm skin and
mucous membranes. The solution must be handled with the greatest of care. Always wear
protective goggles and protect hands with rubber gloves.

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Engineering Department

3.5.5 Adjusting the Gaskets

A gasket that has become loose, either partly or entirely must be glued in place. If only a
short length has become detached, gluing can be carried out immediately before
clamping, with the plate still sitting in the frame. If the entire gasket has become
detached, the plate should be taken out of the heat exchanger.

When cleaning the gasket groove, the solvent must not contain chlorine. Clean the plates
from residues of old gasket. Small patches of glue that are securely stuck to the gasket
groove may remain there. They provide an excellent foundation for the new gasket. Wash
the gasket groove so that it is completely free of oil and other greasy substances, using a
rag and acetone or other solvents not containing chlorine compounds. Then let the plate
dry off.

Glue is applied with a small flat brush to those parts of the plate’s gasket groove in which
the gasket lies.

3.5.5 Gluing the Gasket

Glue is applied with a small brush to those parts of the plate’s gasket groove in which the
gasket lies. These parts of the gasket groove are easily recognised as they differ in colour
arising from previous residues of glue.

The gasket is then placed into position on the plate. After drying for about 30 seconds
(depending on thickness, ambient temperatures and the amount used), the glue holds the
rubber gasket firmly in place in the groove, thus facilitating mounting. The plate must
then be held under light pressure with the aid of other plates or a stiff sheet of other
material of suitable weight for about half an hour.

When the glued joint has dried, the gasket should be coated with talc to prevent the plates
subsequently sticking to each other. The plates are then ready to assemble into the frame.

3.5.6 Assembly

Before the heat exchanger is assembled, inspect all gaskets and surfaces that lie against
the gasket. Particles that may jeopardise the integrity of the seals or damage the gasket
sealing surfaces must be removed.

NOTE: Contaminants usually collect at the lower part of the plates

Plates that have been provided with new gaskets must be checked to make sure that the
gaskets are in the correct gasket groove. Also check the half thickness gaskets on the first
and last plates.

The plate edges form a regular honeycomb pattern.

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Temperature Control Manual Version 0.1

Date: 1/02/2007
Heat Exchanger Prepared By: Justin Day
Engineering Department

3.5.6 Tightening the PHE

The plate pack must be compressed to a specific thickness – the A-dimension. The A-
dimension +/- 3% gives the inside length in millimetres between the fixed and movable
cover.

WARING: Never tighten the Heat Exchanger whilst under pressure

With large plate packs the A-Dimension, due to tolerances in the plate thickness and
depth of pressing, can deviate somewhat from that given above (+/- 3 %). With the
correct A-Dimension the plates lie in metallic contact with each other. Check this by
examining the plate edges around the heat exchanger. Further compression can deform
the plates.

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Temperature Control Manual Version 0.1

Date: 1/02/2007
Heat Exchanger Prepared By: Justin Day
Engineering Department

The Tightening Sequence is as follows:

a. The nuts must be tightened alternately. The movable cover plate must always be
moved parallel to the frame at all times, and not drawn out of alignment.
b. Tighten bolts 3 alternately.
c. As the resistance increased also tighten bolts 1 and 2, again alternately.
d. Tighten bolts 4.
e. Check the A-Dimension along the heat exchanger.

3.5.7 Cleaning-In-Place (CIP)

CIP is the preferred cleaning method when especially aggressive liquids are processed in
a PHE unit. Install drain piping (where applicable) to avoid corrosion of the plates due to
residual liquids left in the unit after an operation cycle.

To prepare the unit for cleaning, follow the procedures listed below:
a. Drain both sides of the unit. If it is impossible to drain, then force liquids out of the
unit with flush water.
b. Flush the unit on both sides with warm water at approximately 400C until the
effluent water is clear and free from process fluid.
c. Drain the flush water from the unit and connect CIP pump.
d. For thorough cleaning it is necessary to circulate the CIP solution from the bottom
to top to ensure wetting of all surfaces with cleaning solutions. When cleaning
multiple pass units it is necessary to reverse the flow of the cleaning solution for at
least half the cleaning time to wet all surfaces.
e. For optimum cleaning, use a flow rate of water, rinse and/or CIP solution that is
greater than normal product rate of flow. A CIP operation will be most effective if
performed on a regularly scheduled basis and prior to the unit becoming
completely fouled.
f. Flush thoroughly with clean water after CIP cleaning.

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Temperature Control Manual Version 0.1

Date: 1/02/2007
Heat Exchanger Prepared By: Justin Day
Engineering Department

Cleaning Example 1: Protein or grease deposits

a. Rinse with water immediately after using the process fluid.
b. Circulate a 2-3% caustic soda solution at 800C for thirty minutes.
c. Flush with sufficient amount of water.
d. Circulate a 0.5% nitric acid solution at 650C (alternatively a 2 % phosphoric acid
solution at 800C) for fifteen minutes.
CAUTION: Nitric acid attacks elastomer gaskets.
e. Flush with sufficient amount of water until the acid is completely rinsed out of the
PHE and the pipe system.

Cleaning Example 2: Lime-scale deposits

a. Circulate a 2-3% phosphoric acid solution at 200C for two hours.

b. Flush with sufficient amount of water until the acid is completely rinsed out of the
PHE and the pipe system.

TC Manual Heat Exchanger.doc Aggreko Australia Pacific