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FEED YOUR SYSTEM WITH GRUNDFOS KNOW-HOW

GRUNDFOS INDUSTRIAL SOLUTIONS

BUILDING UP STEAM WITH GRUNDFOS

Level control through feed valve

• Level sensor provides signal to control valve• Continuous pump operation and bypass

With Grundfos by your side you are in safe hands when it comes to steam boiler applications. Our boiler feed solutions are backed by decades of experience to offer you the best match for your requirements:

On/off control: Inexpensive solution suitable for less demanding applications.Feed valve: Solid solution offering smooth operation and low risk of cavitation.Direct boiler feed: State-of-the-art solution designed for unrivalled level control, high steam quality and reduction of life-cycle cost.

Whatever your choice, your feed pump will be based on Grundfos’ renowned quality. Designed to withstand high pressure, high media and ambient temperatures and a significant number of starts and stops, our pumps have been optimised in every aspect – and can even efficiently handle poor inlet conditions. We also offer controls for duty/standby or duty assist if the system features parallel pumps.

Grundfos offers a wide range of feed pump solutions for steam boiler applications in virtually any type of industrial process. Which to choose depends on your specific requirements in terms of steam quality, operational stability and life cycle cost.

CRN MAGdrive pump

CRNE 32-10 18.5 kW pump with sensor

CRN 150 pump with air cooled top

ON/OFF CONTROLA feed pump with on/off control is a relatively inexpensive solution in a variety of boiler applications. The pump is easy to install and requires no bypass.

FEED VALVEFeed valve pump systems offer smooth operation in steam boilers of any type and size. A main advantage is the ability to maintain constant water levels in the boiler, regardless of steam consumption.

On/off control uses a level sensor to switch the feed pump on and off. When the water level drops to a predefined start level, large quantities of relatively cold water are pumped into the boiler until the required water level is reached.

In feed valve systems, the feed valve receives its signal directly from a level sensor. Water intake is reliably controlled by the feed valve and adjusted according to steam consumption. The feed pumps simply supply surplus flow and pressure.

ProsBoiler feed with feed valve:• Adjusts the boiler feeding according

to the steam consumption• Ensures high steam quality

Cons• Continuous pump operation increases

energy consumption• Expensive feed valve• Bypass is required (unnecessary energy loss)• Pressure loss across the feed valve

Grundfos options• CR multi-stage high-efficiency pumps with MGE

motors or CUE drive with MG motors (IE3)• Pressure transmitters• Motor protection (MP204) with monitoring

function and BUS communication• MPC controls for duty/standby function

ProsThe feed pump with on/off control is:• Inexpensive• Easy to install and features no bypass• Efficient and offers high performance

pump operation

ConsThe feed pump with on/off control may cause:• Poor steam quality • Cavitation in feed pumps• Water hammering• Mechanical stress on the boiler structure

Grundfos options• CR multi-stage high-efficiency pumps with MG

motors (IE3)• Pressure transmitters• Motor protection (MP204) with monitoring

function and BUS communication• MPC controls for duty/standby function

Deaerator

Steam boilerFeed pumps

Controlbox

Levelsensor

Burner

Deaerator

SteamboilerFeed pumps

Bypass

Levelsensor

M

Burner

Traditional solutions• On/off control utilising a level sensor

GRUNDFOS HAS THE SOLUTION

The Grundfos boiler feed product line is part of the wider Grundfos portfolio of pumps and pump systems. Our solutions are backed by decades of solid system knowledge and built on innovative products that push technological boundaries.

Boiler feed specialists will appreciate the full range of Grundfos products for steam boiler applications, including the Grundfos Alldos dosing pumps and our full water treatment portfolio for measurement and control.

Controls & Communication

Pump typeFeed water

Pump typeWater treatment

Pump typeCondensate

Pump typeFeed pumps

Hydro MPC CRE TP(E)(D) TP(E)(D)Smart Digital

CR(E) CR(E)DME

CR & CUE NB(E)/NK(E) NB(E)/NK(E)DDI

MTR(E) MTR(E)

CM(E) CM(E)

CIM/CIU

Heavy compensation

Moderate compensation

No compensation

Pros• No pressure loss across feed valve • Unrivalled steam quality• No need for low flow bypass• Pump energy savings

Cons• Requires precise and qualified commissioning

Grundfos supplies• CRE pumps with MGE motor or CUE drive with

MG motors (IE3)• Control MPC and BUS communication• Pressure transmitters• MPC controls for duty/standby function

GRUNDFOS DIRECT BOILER FEED

GRUNDFOS CRE TAILOR-MADE BOILER FEED PUMPS

A boiler feed system directly controlled by a pump with variable-speed drive offers the best possible steam quality – and is by far the most energy-efficient solution.

With customised software, the variable speed Grundfos CRE pumps can operate outside their set pump curves for unrivalled performance in boiler feed systems.

A boiler system equipped with a Grundfos E-solution guarantees smooth operation in any type of steam boiler – large or small. As the water level in the boiler is controlled directly by a variable-speed pump, the need for expensive feed valves is completely eliminated. A level sensor positioned on the boiler controls the pumps to ensure that the water intake is adjusted according to the steam consumption, maintaining a constant level. The result is an extraordinarily high steam quality and tangible energy savings on the pump operation.

The only downside of a direct boiler feed system is that is requires precise and qualified commissioning.

Grundfos’ software can be tailor-made to achieve pump curves that fulfil even the most demanding needs. The secret lies in getting the pump to straighten out the pump curve and avoid the natural labile tendency created by high-efficiency hydraulic design. This optimisation of frequency converter software creates a steep pump curve with only one correct duty point to completely eliminate the risk of random excessive water intake.

Standard versus customised software• The standard software in all modern variable-speed drives requires that the regulation loop is in normal regulation. They are not capable of

handling the change from normal to inverse regulation and back again.

• Grundfos customised software for boiler feed applications provides constant pump curves and eliminates the risk of two duty points at the same pressure. At the same time, it eliminates the risk of excessive water intake since there is now only one duty point for any given flow.

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Constant speed pump curve

Inverse regulation Normal regulation

Setpoint

Moderate curve compensation

Powerful curve compensation

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Q

rpmQrpm

Qrpm

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50 Heavy compensation

55 Moderate compensation

58 No compensation

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Graph showing variable-speed drive pump curves

GRUNDFOS Holding A/SPoul Due Jensens Vej 7DK-8850 BjerringbroTel: +45 87 50 14 00www.grundfos.com

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Feed your system with Grundfos know-how

Whatever the demands for steam quality, operational stability and energy efficiency in your boiler feed application, Grundfos has the solution.

As a full-range supplier of efficient boiler feed solutions, we offer customers access to decades of solid system experience and an extensive product portfolio renowned for its quality and reliability.

Visit grundfos.com for more information on our boiler feed solutions.