GEA Steam jet heaters User Manual

87GEA Wiegand GmbH 76275 Ettlingen · Germany · Tel.: [phone]

www.gea-wiegand.com Fax: [phone] · E-mail: [e-mail]

Steam jet heaters for vessels

APPLICATION

Steam jet heaters are used to heat all kinds
of liquids in vessels. Heating is achieved by
means of direct condensation of steam. The
steam condensate mixes with the liquid.

MODE OF OPERATION

The steam jet emerging from the motive
nozzle accelerates the liquid present in its
vicinity and in the mixing nozzle, and con­denses (see also “General information on jet
pumps”,

o

| abl1).

In this way a controlled flow is produced.
Furthermore, the whole content of the ves­sel is set in motion and the heat transferred
to the liquid is evenly distributed through­out the vessel.
All the heaters are provided with a threaded
connection for an air pipe. Normally it is not
necessary to operate with air supply. How­ever, the admission of air greatly intensifies
the movement of the circulating liquid; it
can also assists in avoiding condensation
hammers and rattling that may occur when
starting with a cold liquid.
If air is to be supplied, a corresponding line
with installed regulation valve has to be con­nected (see fig. 1). Depending on the applica­tion, atmospheric air which is sucked in by
the heater itself is sucient.
To operate the steam jet heater, a steam
overpressure of at least 1.5 bar is necessary
to overcome the static pressure of the liquid
and to achieve the minimum speed at which
no disturbing noise is produced.
The heaters described can also be used for
operating with low pressure steam (special
construction).

FIG. 1

A Motive steam
B Liquid
L Air

PERFORMANCE CHART

On the bottom scale, the chart in fig. 2 gives
the heat flow in kW for each size. This is the
heat content of the inflowing steam. Howev­er, the heat actually transferred to the liquid
is less. It is reduced by the heat contained in
the condensate.
The condensate flow produced by the con­densation of the inflowing steam is given on
the top scale. With the aid of this scale and
the temperature ϑ of the heated liquid, the
heat flow actually transferred is calculated
as follows:

Whereas:

œtr Transferred heat flow in kW

œ Heat flow in kW = Enthalpy of the

inflowing steam

Ø

Condensate flow in kg/h

C

c Specific heat capacity of the condensate

in kJ/kg °C (water = 4.2)

ϑ Temperature of the heated water in °C

EXAMPLE

GIVEN:

A steam quantity of approx. 70 kg/h
is required to heat a vessel.
Steam at 2 bar g is available.

SOLUTION: The chart in fig. 2 shows that size

1-80 matches the example.

FIG. 2

Steam consumption Ø

or condensate ØC in kg/h or kg/s resp.

D

Construction with thread

Construction with flange

Steam pressure in bar g

Heat flow œ in kW ¥ Enthalpy of the inflowing steam

Performance chart for steam jet heaters, size 1 to 7, construction series 80, for water

Steam jet
heaters,
sizes 1–7,
series 80

aw1 09

GEA Wiegand GmbH 76275 Ettlingen · Germany · Tel.: [phone]

www.gea-wiegand.com Fax: [phone] · E-mail: [e-mail]

88

Steam jet heaters for vessels

Steam jet heater with thread, type 18.1

A Motive steam
B Liquid
L Air

EXAMPLE OF INSTALLATION : STEAM JET HEATER WITH THREAD, TYPE 18.1

FIG. 3

FIG. 4

CONNECTIONS, DIMENSIONS AND WEIGHTS
STEAM JET HEATER WITH THREAD, TYPE 18.1

Size 1-80 2-80 3-80 4-80 5-80 6-80 7-80

Nominal diameter A G 3/4 G 1 G 1 1/2 G 1 1/2 G 2 G 3 G 4

L G 1/8 G 1/8 G 1/4 G 1/4 G 1/4 G 3/8 G 3/8

Dimensions in mm a 170 220 265 345 400 520 610

D 52 60 75 85 100 125 160

e 35 40 40 40 50 75 80

f 20 25 24 24 30 33 40

Weight in kg 1 2 3 5 7 12 21

STANDARD CONSTRUCTIONS:

I Housing: cast iron EN-GJL-200 (GG20), motive nozzle: red brass
II Housing: cast iron EN-GJL-200 (GG20), motive nozzle: stainless steel
III Housing: cast stainless steel (1.4581), motive nozzle: stainless steel
Thread according to DIN ISO 228

SPECIAL CONSTRUCTIONS are possible in most of the usual materials.

Please indicate size, type and material with your order.

For inquiries please use our questionnaire.

aw1 09