FläktGroup EQES Air heater steam Installation and Maintenance Manual

Brand: FläktGroup

Model: EQES Air heater steam

Type: Installation and Maintenance Manual

FläktGroup EQES Air heater steam lets you control temperature and pressure with the use of reducing valves and regulation functions. The device should be positioned horizontally and connected with piping and trapping installed in a way that does not cause extra weight or pressure on the coil. Accessories like flanges, strainers, and vacuum beakers can be added to facilitate installation and maintenance. FläktGroup EQES is equipped with a condensate trap and a non-return valve to prevent overflows and water hammer.

FläktGroup DC_8678GB 20180228_R0 Speciﬁcations are subject to alteration without notice

TEMPERATURE

The temperature of the steam should not exceed the maximum operating

temperature prescribed for the air heater.

PRESSURE

If the steam pressure is in excess of maximum operating pressure

prescribed for the air heater a reducing valve should be mounted.

REGULATION

In the case of air heaters connected in series (as viewed in the air flow

direction) and where the temperature of the entering air may be sub

zero, the first air heater should operate at full steam while the second air

heater is regulated (see Fig. 4, page 3). Regulation of the first air heater

will only increase the risk of the coils freezing up and should be avoided.

POSITIONING

The air heater is designed for horizontal air flow.

CONNECTIONS

The piping and trapping etc. should be installed in such a way that

its weight will not bear upon the coil, nor press against it through

mechanical expansion.

ACCESSORIES

To facilitate the installation or replacement of traps, valves etc., the air

heater connections may be fitted with flanges.

EQES AIR HEATER, STEAM

AIR HEATER, STEAM

INSTALLATION AND MAINTENANCE INSTRUCTIONS

Installation and maintenance instructions

FläktGroup DC_8678GB 20180228_R0 Specifications are subject to alteration without notice

AIR HEATER, STEAM

SYMBOLS

Steam main

Return main

Flexible fitting

Fixing point

Gate valve

Shut-off valve

Control valve

Strainer

Vacuum breaker

Dirt pocket and valve

Petcock

Condensate trap

Non-return valve

Condensate pump

Steam

Condensate

Air

Direction of flow

Direction of air flow

Pitch (arrow indicates direction of flow)

To overhead return main

3154 EUES SYMBOL ÅNGLEDNING

3154 EUES SYMBOL KONDENSATLEDNING

3154 EUES SYMBOL KOMPENSATOR

3154 EUES SYMBOL FIXPUNKT

3154 EUES SYMBOL STOR AVSTÄNGNINGSVENTIL

3154 EUES SYMBOL REGLERVENTIL

3154 EUES SYMBOL SIL

3154 EUES SYMBOL VAKUUMVENTIL

3154 EUES SYMBOL LUFT

3154 EUES SYMBOL AVÖUFTARE

3154 EUES SYMBOL KONDENSAT

3154 EUES SYMBOL ÅNGA

3154 EUES SYMBOL BACKVENTIL

3154 EUES SYMBOL KONDENSATAVLEDARE

3154 EUES SYMBOL FLÖDESRIKTNING

3154 EUES SYMBOL LUFTRIKTNING

1:100

3154 EUES SYMBOL LEDNINGSLUTNING

3154 EUES SYMBOL TILL ÖVERLIGGANDE KONDENSATLEDNING

3154 EUES SYMBOL KONDENSATPUMP

3154 EUES SYMBOL SMUTSFICKA MED AVTAPPNINGSVENTIL

3154 EUES SYMBOL AVSTÄNGNINGSVENTIL

Installation and maintenance instructions

FläktGroup DC_8678GB 20180228_R0 Specifications are subject to alteration without notice

AIR HEATER, STEAM

3154 EUES schema

öppet system



Min.500

1 : 100

Fig. 2. Open System

3154 EUES schema

slutet system



Min.500

1 : 100

Fig. 3. Closed System

CONNECTING-UP

To ensure that the system functions properly, the air heater and trapping,

etc. should be installed as shown in Figs. 2–4.

The steam main should always be connected at the top of the air heater

whereas the return main should be at the bottom. See symbols page 2.

3154 EUES schema

två seriekopplade



Min.500

1 : 100

Fig. 4. Two air heaters connected in series on the

air side, b = 2.

Installation and maintenance instructions

FläktGroup DC_8678GB 20180228_R0 Specifications are subject to alteration without notice

AIR HEATER, STEAM

3154 EUES Tryckförhållanden

Fig. 5. Pressure conditions with overhead return line.

hm < p1 – p2 kp/cm2

10,3

CONTROL AND PIPING

The piping should be pitched to ensure that the condensate build-up is

drained off, and not admitted into the coil.

The return main should be pitched downward from the air heater.

All the accessories which are part of the system must be designed

for steam or for condensate respectively. They should be sized for the

pressure, temperature and flow for the installation concerned, and be

connected according to the recommendations of the manufacturer.

STEAM AND RETURN MAINS

As a rule, steam mains should be sized for high vel oci ties. The steam

should be dry and preferably super heat ed. Humid steam leads to corro-

sion in the piping and may damage the air heaters and accessories

through water hammer.

The steam main should be drained of condensate upsteam of the air

heater and accessories by means of a shunt valve. The take-off should

be mounted as near to the air heater as possible and be designed to

separate the steam from the condensate in the pipe.

If the return main is pitched higher than the condensate trap, the coil will

operate at a static overpressure resulting from the w.g. height ”h” (see

Fig. 5) and the pres sure drop (i.e. resistance) in the condensate trap and/

or other accessories. Consequently this form of over head return main

should be avoided.

The steam and condensate pipes should be sized accord ing to the

recommended load and not according to the connection size of the air

heater.

MEASUREMENT OUTLET

If possible, the system should be fitted with an outlet to permit

measurement of the pressure, flow and temperature, both ahead of and

after the air heater.

FLEXIBLE FITTINGS

Flexible fittings should be provided in all piping connections so as to

absorb expansion and contraction strains. Rigid piping connections can

cause serious physical damage to the air heater coil.

FIXING POINTS

All fixing points should be as close to the air heater as possible, so

as to protect it from the weight of the pip ing, valves etc., and from the

expansion strain.

GATE VALVES

Gate valves should be mounted ahead of, and after, other accessories.

This will facilitate cleaning of the strainer and replacement of trapping,

valves, etc.

CONTROL VALVES

The control valve should be sized according to the manu facturer’s

recommendations and not according to the size of the air heater

connections.

An electric regulating motor should not be mounted under the valve, as

water leakage from the valve will cause damage.

The control valve should be mounted as close to the air heater as

possible and should be installed according to the manufacturer’s

instructions.

See symbols page 2.

Installation and maintenance instructions

FläktGroup DC_8678GB 20180228_R0 Specifications are subject to alteration without notice

AIR HEATER, STEAM

STRAINER

A strainer should be installed ahead of the control valve and condensate

trap, to collect foreign matter such as scales and rust flakes. If they are

not removed, these impurities will prevent the various accessories from

work ing properly and may even cause a stoppage in the throttling discs

of the air heater – thus reducing the heating efficiency and at the same

time increasing the risk of freezing-up.

VACUUM BREAKER

If the supply of steam to the air heater is reduced or shut off, there will be

a vacuum in the air heater, with the result that it will wholly or partly fill

with conden sate. If the temperature of the outside air is so low that the

coil may freeze up, the water must be emptied and the air heater filled

with air instead. This is the function of the vacuum breaker. In air heaters

where there is no danger of freezing up, a vacuum breaker need not be

used; the risk of corrosion will be reduced accordingly.

DIRT TRAP AND DRAIN COCK

It is recommended that a dirt trap be installed before the condensate

trap. Thus it will not be necessary to clean the strainer so often.

PETCOCK

Air which has entered the system through the vacuum breaker, and

likewise non-condensible gases from the steam, must be eliminated.

This is done by means of the petcock, which should be installed ahead of

the condensate trap.

STEAM COIL

Check that there is steam pressure up to the heating coil (the boiler must

have correct steam pressure and all the valves must be open) and that

the condensation discharge pipe and provision for venting work properly

throughout the system. A fault in the steam trap may adversely affect all

the discharge pipes.

CONDENSATE TRAP

Each air heater (or tube row) should be provided with a condensate trap.

A single condensate trap should not be connected to more than one air

heater, regardless of its operation.

The condensate trap also prevents a return flow of steam to the coil via

the return line.

The condensate trap should be sized according to the amount of

condensation when the air heater is cold. Its capacity in litres/h should

be three to five times the calculated steam flow in kg/h.

The trap may be of such a type that a separate strainer and venting valve

will not be required.

Important!

The strainers should be controlled at short

intervalls right after start-up.

To ensure that the condensate is emptied completely, the trap should be

installed at least 500 mm below the pipe connection of the air heater.

In the case of a thermostatic condensate trap, a cool ing length of piping

is required between the air heater and the trap.

If the air heaters are connected in series (see Fig. 4, page 3) the maximal

heat is produced by the first air heater. Its condensate trap must

therefore be selected with this in mind.

NON-RETURN VALVE

To prevent water hammer from other units connected to the system, the

installation should be fitted with a non-return valve or a condensate trap.

When two air heaters are installed, each of them must be provided with a

non-return valve, to prevent an overflow of steam.

CONDENSATE PUMP

If an overhead return main is installed, the pump should be located before

the rise; this reduces the risk of cavitation in the pump, and ensures that

the condensate is emptied completely.

Installation and maintenance instructions

FläktGroup DC_8678GB 20180228_R0 Specifications are subject to alteration without notice

AIR HEATER, STEAM

Fig. 6. By-pass

FREEZE GUARD THERMOSTAT

Steam air heaters supplied with outside air should be protected by

means of a freeze guard thermostat, to be selected and mounted

according to the instruction. However, its sensing element should be

mounted so that it does not come in contact with un heated air.

With capillary tube thermostats, the element should be located at the

bottom of the air heater coil, on the condensate side, and not over the

entire face area. If the thermostat is of the bulb type, it should likewise be

mounted in the lower part of the coil, and parallel with the finned tubes.

If the thermostat is not temperature-compensated, its cubicle should

be mounted in a location where the temperature is higher than that

required to trip the circuit breaker. If the cubicle of a thermostat which

is not compensated, is mounted on the casing of an air heater, or a duct

upsteam of the air heater, it should be insulated by means of a wood-

fibre board or the like.

BY-PASS

Replacement of the regulating valve or condensate trap will be facilitated

if a by-pass is installed as shown in Fig. 6.

See symbols page 2.

STARTING-UP

Open the steam valve until the entire air heater is warm, then start the fan

motor.

If the temperature if the outside air is below 0°C, there is risk of the air

heater coil freezing, see “vacum breaker”.

Important!

When installing air heaters which use steam

as a heating medium, great care should be

exercized when opening air vents and gate

valves. Failure to do this may result in serious

damage through water hammer or a discharge

of steam.

FläktGroup assumes no responsibility for the

connection of air heaters to the heating system,

or for any damage which may arise through

faulty planning, installation or maintenance of

such system. Piping, valves, etc. should be

sized according to pressure drop and function

and not according to the size of the air heater

coil connections. The pipes should be installed

in such a way that the air heater does not bear

their weight or is not subjected to expansion

and contraction strain from the heating system.

The guarantee does not cover air heaters which

have been damaged through water hammer or

freezing.

Installation and maintenance instructions

FläktGroup DC_8678GB 20180228_R0 Specifications are subject to alteration without notice

AIR HEATER, STEAM

TO CLEAN

Even a very efficient air filter cannot remove all dust from the air. Dust

deposited on the heat transfer surfaces restricts the air flow and impairs

the heat transfer.

The finned unit must therefore be kept clean, for which one of the

methods described below or a suitable combination of these methods

can be employed.

A. Blow clean with compressed air.

B. Blow clean with steam.

CHECK

Check that there is steam pressure all the way to the heating coils (the

boiler must have the correct steam pressure and all the valves must be

open) and that the condensate trap and venting valves are in working

order throughout the system. One faulty condensate trap can give rise to

repercussions on all the traps.

After cleaning but before starting the fan, remove all dust that has fallen

down.

Caution!

The heating elements are still hot after you have

switched off the unit. You risk getting burned

if you touch them. Switch off the unit well in

advance before cleaning.

FläktGroup EQES Air heater steam Installation and Maintenance Manual

FläktGroup EQES Air heater steam Installation and Maintenance Manual

FläktGroup EQES Air heater steam Installation and Maintenance Manual

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