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» The Power To make Things move

NEM Power-Systems

NEM Power-Systems

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Company profile

NEM Power-Systems is a subsidiary of

NEM Energy b.v. in the Netherlands, a

company with activities in the field of

energy and environmental technology all

over the world. NEM has become one of

the world’s largest producers of Heat

Recovery Steam Generators (HRSGs)

behind Gas Turbines.

Dampers are an important part of these

systems, so it was a logical step to

acquire access to the technology and to

take over the staff of the former

Stober+Morlock organization in Ger-

many. NEM Power-Systems has taken

over all the drawings and patents and

has continued with the complete

damper program.

Office NEM Power-Systems in Recklinghausen, Germany.

Head office NEM Energy b.v. in Leiden, the Netherlands.

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Contents and worldwide activities

- Exhaust Gas Systems 4

- Diverters 6

- Louvre Dampers 8

- Stack Dampers 10

- Flap Dampers 11

- Guillotine Dampers 12

- Safety Dampers 13

- High Temperature Dampers 14

- Installation, commissioning and maintenance 15

Worldwide activities.

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exhaust gas systems

Exhaust Gas Systems are designed with an elbow for connecting to

the exhaust stack in simple cycle power plants and bypass systems

with a diverter damper, or T-Box, in combined cycle power plants. With

a delivery time of only six to eight months, a bypass stack can be

installed to allow power generation ahead of the HRSG erection.

The advantages of a bypass system with diverter are:

- Controlled start-up of the HRSG reduces thermal stress and

prolongs lifetime

- Flexibility during HRSG maintenance

NEM Power-Systems has supplied a large number of exhaust gas and

bypass systems with stack diameters ranging from 2.600 to 7.600

millimeters stack heights between 25 and 65 meters and design gas

temperatures up to 680 oC.

CapabilitiesNEM Power-Systems has all the in-house engineering facilities nec-

essary for producing the static and dynamic analyses for bypass sys-

tems according to all internationally recognized codes.

Fabrication may be performed worldwide with supervision services

provided by our own experienced personnel. Erection and commis-

sioning services are also provided worldwide by NEM Power-Systems.

«5scope of supply

The scope of supply typically involves expansion joints, as cold/cold

or hot/cold connections in the ducting, a horizontal transition duct

from the gas turbine diffuser to the elbow or diverter, the elbow,

diverter damper or T-Box, hot gas silencer in the stack, structural

steelwork and the stack. The stack and silencer housing are designed

as self-supporting structures.

The ducting and stacks are internally lined with high quality insula-

tion material which is retained by stainless steel cladding.

Ancillary equipment e.g. aircraft warning lights, emission ports and

stack dampers for locations with high rainfall are supplied on a case-

by-case basis.

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Diverters

Diverter dampers are used to switch gas streams and to isolate equipment and

processes in desulphurizating or DeNOx plants, combined cycle gas turbine/steam

generator power stations and other similar applications. The special design for com-

bined cycle systems is based on the experiences of at least three decades.

Critical components (drive systems, blades sealing surfaces, etc.) are designed uti-

lizing Finite Elements Analysis (FEA) for both thermal and mechanical loadings,

steady stand and transient operation conditions.

one important stepThe toggle arm drive system was invented by us to handle the drive problems at

big diverters and to prevent blade flattering, even at high gas velocities.

«7Delivery

If possible, the diverter will be sent to

site completely assembled in one piece.

When local transport limitations require

smaller units, the diverter can be deli-

vered in two, four or more parts. The

assembly should be supervised by our

specia lists.

Finite elements analysis (Fea)Due to the high number of cycles

required by most gas turbine specifica-

tions, we have designed (by means of

FEA calculations) all important diverter

parts, like shafts/pipes, seats, blades

and toggle arm systems.

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Louvre Dampers

The program includes the complete range of shut-off and regulating dampers for

power stations, gas cleaning systems, cement plants and chemical industries.

Some basic construction guide lines, like continuous shafts or approved blade

designs, are together with a few patents the basis of this program of single and

multiple blade louvre dampers.

Double linkages with automatic compensation of thermal expansion, self aligning

stuffing boxes and the dust-insensible, continuous sealing cone are just a few of

the inventions of our engineering team.

«9The tightening principles

The elastic sealing and the cone was the most important reason for

the high reputation of the Stober Damper. Today we offer lamella

sealings for gas turbines and coal fired systems. For one hundred

percent tightness we offer a twin lamella seal design with seal air.

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stack Dampers

The dampers are used for two main pur-

poses:

- Saving energy by closing the stack

and reduction of cooling down by

na tural draft during short boiler stops

- Weather protection and rain water

drainage for stack, silencer and boiler

The newest version of the standard

stack damper has a new blade design

and an improved drive system, provi ding:

- Independent pressure relief on the

blades

- Reduced actuator torques

- Cross sectional area loss has been

minimized to achieve a very low pres-

sure drop

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Flap Dampers

The advantages of flap dampers are:

- Big blades with less sealing length and very low

leakage

- With double sealings and the use of seal air,

a simple underload maintenance of plant parts is

possible

These dampers are available with single and double

sealings and in case of corrosion problems with heated

seal air for one hundred percent tightness. The differ-

ential pressure should assist the sealing effect.

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guillotine Dampers

The advantages of guillotine dampers are:

- Low pressure drop and high tightness

- Plate and sealings are normally out of the gas stream

- Short face-to-face length

- Low seal air requirements

Guillotine dampers are generally used when space limitations do not

allow longer damper casings. As stand-alone solutions, this damper

type will often be used in coal fired power plants where high ash accu-

mulation has to be handled. But also applications for gas turbine

plants are available. Almost the full cross-section of the duct is avai-

lable once the guillotine blade is fully retracted, causing a very low

pressure drop.

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safety Dampers

Quick opening or closing and pressure relief are the main purposes of this damper

type. For small dampers, we prefer weight and spring systems. For bigger louvre

dampers, we use pneumatic or hydraulic cylinders with accumulators for emergency

functioning.

standard design for larger safety louvre dampers: - Electric actuator for normal operation

and regulation

- Pneumatic or hydraulic cylinders with

accumulators for safety function

(open or closed), even in case of com-

plete energy loss

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high Temperature Dampers

The program includes:

- Butterfly and louvre dampers

- Guillotines

- High temperature alloys

- Ceramic linings

- Fire resistant concrete for frames and blades

- Air cooled, ceramic felt insulated shafts

No water cooled systems are included.

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installation, commissioning and maintenance

A qualified team of experts is available for:

installation- Technical advice for local assembly personnel

- Complete installation, including crane, scaffoldings,

etc.

CommissioningWe recommend this work to be supervised by our

experts, especially for more complicated systems like

diverters, guillotine dampers, multilouvre dampers with

seal air systems, etc..

maintenanceSimple standard dampers can be checked by local

plant staff, using our handbook. Diverters, guillotines

and safety dampers should be checked by our specia-

lists during the standard shutdowns, preferably once

a year.

Our teams of specialists are available worldwide! Every

job will be completed with a test program, supervised

by our relevant site personnel with a final acceptance

protocol.

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experience and high technology:the solid base for the nem damper program

Follow-up and feedbackIt has been our pleasure to show you

what NEM Power-Systems does best

and that our established business part-

ners would also see something new. If

you have any comments or questions,

we are just a phone call or e-mail away.

nem Power-systemsSibylla-Merian-Strasse 3

45665 Recklinghausen

Germany

Telephone +49 2361 98690

Fax +49 2361 98294

E-mail info@nem-ps.com

Website www.nem-ps.comNEM Power-Systems