|
Send question
We are pleased about the brisk demand of
informations about our products and therefore provide the
historically grown list of questions given below.
How does the VOIGT-Lifter
work in detail?
How can I telemonitor the
functioning of the VOIGT-Lifter?
Does the initial pressure of the
condensate influence the function of the lifter?
How can I control
the functioning of the VOIGT-Lifter?
Which maintenance
and care procedures have to be considered?
Why are no
non-return flaps suggested for the
What is a „loader“
in arborescent pipe networks?
Why should I
dismantle the feather in the check valve of the inlet line?
How can I prevent a
freezing of the lifter when it is installed outdoor?
How high is the
steam demand of a VOIGT-Lifter?
According to which
design codes is the VOIGT-Lifter manufactured?
How does
the VOIGT-Lifter work in detail?
In principle the
VOIGT-Lifter works instead of a pump. It has to be seen as a
more significant alternative to a pump.
The condensate flows into
the VOIGT-Lifter from a collection tank or collecting pipe
through the suction line of the lifter. These condensate
collection drums are considerably smaller than the tanks of
conventional pumping systems. The size of the collection
drum ranges only from 100 to 600 l.
With an increasing
air-fluid level the built-in float moves upwards and
activates the exterior attached control. The steam-inlet
valve opens, the check valve in the suction line closes. The
delivery process starts. The pressure in the VOIGT-Lifter
raises, not depending on the driving steam pressure,
correspondent to the pressure in the pressure line, the
condensate is displaced by steam.
Because of thermodynamic
efficient internals the steam impinges very elastic on the
fluid in the vessel. Therefore the delivery process is
nearly noiseless and furthermore condensate impacts are
averted.
With the decreasing
condensate level in the VOIGT-Lifter, the internal float
slides downwards and activates the control again. The steam
inlet valve closes and the steam outlet valve opens. The
residual steam is led into the condensate collection drum
through the venting pipe and the operation cycle is finished.
The next operation cycle can start.
The VOIGT-Lifter works as
long as condensate is provided and shuts down when no
condensate is available. Fully automatic. He then starts
working as soon as condensate accrues again.
The cycle time is about
60 seconds, whereas the ratio of inlet time to delivery
process is about 2:1.
You find a detailled description of the
function
here.
How can I
telemonitor the functioning of the VOIGT-Lifter?
Two solutions are
possible:
The pressure ratio in the
VOIGT-Lifter changes at each working stroke. With a pressure
gauge these pressure pulses can be transferred.
Furthermore the
collection drum can be provided with a niveau-level control.
When the condensate level reaches a critical value a signal
will indicate a problem.
Does the initial pressure
of the condensate influence the function of the lifter?
During the inlet phase
the lifter is connected to the collecting tank by its
relaxation line. Thereby pressure balance exists so that
condensate (unpressurized, pressurized or under vacuum) can
flow into the lifter.
That means that the
condensate pressure has no influence on the functioning of
the lifter.
How can I handle basic
and peak load?
In certain processes
basic and peak load differ substantially. It is therefore
advisable to use one lifter with a smaller capacity for the
basic load which works continuously. For peak load a second
lifter with an appropriate capacity will automatically start
working when the condensate level in the buffer tank rises
over a certain level (dipped pipes).
The inlet pipe of lifter
one for example ends on a level of 150 mm over the tanks
lower edge. This height will only be slightly exceeded in
the basic load lifting phase. The inlet pipe for lifter 2
(peak load) ends about 250 mm over the tanks lower edge. If
the condensate level rises up to this niveau, the second
lifter starts working fully automatic and stands still as
fully automatic when the condensate level in the buffer tank
falls.
This
situation is also suitable for redundant systems to avoid a
shutdown of the whole system when a problem with one lifter
exists.
Why is the capacity
specified in l/min?
In plant design the
capacity is nearly always indicated in m³/h [t/h]. It is not
assumed that this capacity accumulates over the entire time
line continuously. Flow rates given in units per hour often
disregard the continuity, that means that the condensate can
accumulate in significant shorter periods.
Therefore pumping systems
are often overdesigned to intercept peak loads.
Since the VOIGT-Lifter
works fully automatic when condensate flows into, thus is
steered only by the incoming condensate, it can be laid out
more specialized with a capacity given in l/min.
Why is it so important to
preserve the minimal demanded suction head?
The free inlet into a
VOIGT-lifter is based on the principle of communicating
chambers. During the inlet phase a level and pressure
balance between the collector and the VOIGT-lifter takes
place. The condensate has to overcome thereby resistances in
the inlet line (piping and armatures) and in addition a
minimum flow rate must be ensured, in order to reach the
achievement parameters. Customary valves of different design
and quality are used, which has been considered for the
calculation of the necessary suction head.
The indication of
extremely low suction heads which is done by some
competitors is an unfitting sales argument.
With pressure condensates
however the prescribed suction head can be reduced or
omitted, if the relaxation line of the VOIGT-Lifter is
merged into a line with lower pressure.
How can I control the
functioning of the VOIGT-Lifter?
It is not possible to
detect the working of the VOIGT-Lifter by its noise level in
the surrounding field of industrial plants.
How high must the minimal
driving steam pressure be?
The driving
steam pressure should have 2 bar in minimum and should not
be higher than 15 bar.
The used
driving steam pressure is actual as high as the pressure in
the connected pressure line, that means that the pressure in
the lifter rises just up to this level.
To
guarantee the correct functioning of the lifter the driving
steam should be 0,3 bar higher than the pressure in the
pressure line (back pressure).
What belongs to the scope
of supply of a VOIGT-Lifter?
The VOIGT-Lifter is
supplied as fully automatic condensate return system.
Beyond that there are the
following delivery variants:
· With
all necessary valves, pressure gauge
· With
collecting / buffer tank
· With
all necessary valves and piping, condensate collecting tank
and steel construction mounted on base plate (Condensate
Module: pressureless or overpressure/vacuum)
Does a VOIGT-Lifter need
specific valves?
No.
The whole
concept of the VOIGT-Lifter is designed for customary valves.
Which working mediums are
common for a VOIGT-Lifter?
For condensate return
steam offers itself as driving and/or working medium
primarily. In addition, inert gases, nitrogen or compressed
air can be used.
Which function has the VOIGT-Lifter in internal
If condensate can be
returned with the internal pressure of the system, this is
the simplest solution. In many cases however these systems
come to a partial stop and/or the discharge of the system is
too slowly in case of pressure fluctuations.
Which maintenance and
care procedures have to be considered?
A VOIGT-Lifter works
generally maintenance-free under consideration of its basic
conditions and needs no care.
What do I need as spare
parts?
The VOIGT-Lifter works
over many years disturbance- and maintenance-free also under
difficult conditions. Hence a large spares inventory is not
necessary under normal conditions.
Does the VOIGT-Lifter
need a foundation?
No.
You just need a plane and
flat area for erection.
The base plate has to be
screwed to the ground with anchor bolts.
How can I realize a
priority control with a VOIGT-Lifter?
The VOIGT-Lifter delivers
the condensate continuously to the application site or
boiler house.
How does a VOIGT-Lifter
work under vacuum?
In this case the
VOIGT-Lifter has to be connected by its relaxation line with
the consumer and/or the buffer tank. During the inlet phase
to the VOIGT-Lifter the steam exhaust valve of the control
block is opened, whereby a free connection to the collecting
tank, condenser or other consumer standing under vacuum
exists and thus an all-round pressure balance exists (same
vacuum also in the VOIGT-Lifter).
Why are dipped pipes in
collecting or buffer tanks recommended ?
In condensate systems it
is appropriate, however not condition, to implement the
arriving pipings dipped in order to achieve a phase
separation.
What is the venting / relaxation
line?
Before a filling of the
VOIGT-Lifter after a working stroke is possible again, the
driving steam in the work space has to be evacuated. This is
effected by the venting or
Why should I install a
wafer-type lift check valve in the highest point of the
relaxation line?
It has to be recommended
that a holdup of condensate in the relaxation line should be
reduced to a minimum, since otherwise a back-pressure to the
condensate inlet line could develop. This has to be avoided.
What kind of fluids can I
deliver with a VOIGT-Lifter?
In principle all liquids,
as long as they have no detention or sticking
characteristics, can be lifted with a VOIGT-Lifter.
Why are no non-return flaps
suggested for the
At first sight
intermediate flange check valves seem to be advantageous
concerning the space requirement.
Why is it called
„VOIGT-Lifter“?
Condensate usually
accrues at the deepest point of a plant. Therefore the
condensate intended for the re-use must be lifted to a
certain level again for further utilisation. That can be
done with a condensate lifter or with electrically operated
centrifugal pumping systems.
What about the spare part
supply for a VOIGT-Lifter?
The VOIGT-Lifter is
because of its simple and durable building method designed
for a long lasting working (years) with constant
availability maintaining and maintenance-free.
What has to be concerned
when installing a VOIGT-Lifter?
Under adherence to the
prescribed basic conditions (minimal suction head,
sufficient driving steam pressure) the VOIGT-Lifter has to
be connected with the pipings according to the mounting
schematic.
Do I need a minimal
discharge flow?
No.
If the condensate flows
into the lifter very slowly or if no condensate accrues, the
VOIGT-Lifter remains in its inlet position and only starts
working again when the condensate mirror rises so far that
the internal float activates the control and thereby starts
the operating procedure.
What is a „loader“ in
arborescent pipe networks?
In order to keep the
mechanical expenditures and the initial costs within a limit,
engineers often try to lead as much as possible different
condensate lines on a common collector.
Why should I dismantle
the feather in the check valve of the inlet line?
The flow resistance in
the inlet line of the VOIGT-Lifter has to be kept as small
as possible, in order to get along with a suction head that
is as small as possible.
How can I prevent a
freezing of the lifter when it is installed outdoor?
If the VOIGT-Lifter is
used for condensate return and if this takes place to some
extent continuously, additional measures are void. In
critical cases or in cases of insufficient isolation, a
simple coat heating is sufficient by means of steam-heated
coils of pipe.
How high is the steam
demand of a VOIGT-Lifter?
It is correct to say
steam demand instead of steam consumption, since the working
steam remains warming and mass-laterally to the system.
As already said, it is
always suggestive to aim at a phase separation between steam
and condensate in collecting tanks.
According to which design
codes is the VOIGT-Lifter manufactured?
VOIGT-Lifters are in
generally manufactured according to the most current
national and/or international design codes and standards (PED
97/23/EC, ASME). Country-specific regulations are considered
thereby as the case arises.
The body of the
VOIGT-Lifter is manufactured in two variants.
When and why does the
VOIGT-Lifter replace a steam trap?
This question has to be
regarded differentiated.
Is the suction head
necessary when the incoming condensate is under overpressure?
In standard systems the
collecting tank or the consumer is connected with the
VOIGT-Lifter by its relaxation line. Thus pressure balance
exists, which means that the inlet positive pressure is
waived.
What do I have to
consider in closed condensate
In professional
condensate technology closed systems are to be preferred in
contrast to open systems in principle, because of energy
conservation reasons. With open plants simmering condensates
ease over the vapours pipe, which leads to substantial
losses of energy. Besides also the mass of the water vapours
condensing in the atmosphere is lost to the process. In
addition in the case of putting out of operation of the
plant considerable quantities of oxygen are in-sucked
through the cooling of the condensate, which leads to a
considerably corroding of the system and line parts.
What is the difference
between the VOIGT-Lifter
At first a statement: The
VOIGT-Lifter functions and is unequalled concerning its
industrial fitness.
What data is needed for
the dimensioning of the VOIGT-Lifter?
For the perfect function
of a VOIGT-Lifter minimum basic conditions have to be
fulfilled.
How does a VOIGT-Lifter
work as leach or flash
In the
inlet phase the relaxation valve of the integrated steering
of the VOIGT-Lifter is opened.
Why is cavitation
impossible in VOIGT-Lifters?
The condensate flows into
the VOIGT-Lifter with the systems pressure, that means that
it is not sucked in under normal conditions, whereby
cavitation is impossible.
For which parametres is
the VOIGT-Lifter designed?
Since the VOIGT-Lifter is
used predominantly in the high pressure range as industry
standard, the standard type is appropriate for -1 up to 25
bar
To what extent does the
VOIGT-Lifter correspond to industrial requirements?
According to its material
and strength design for continuous operating, the
VOIGT-Lifter meets highest technical requirements and is
generally considered as the industry standard.
What has to be
recommended in redundant
In theory as many as
desired VOIGT-Lifters could be installed in series to a
collecting system, without affecting each other mutually.
Can I achieve a direct
suction of the VOIGT-Lifter?
In normal operation the
condensate flows into the VOIGT-Lifter.
In certain cases however
the relaxation line of the VOIGT-Lifter can be connected
with a vacuum line, whereby an intake pressure develops in
the work space of the lifter.
What has to be considered
in the EX-range?
A common application area
for the VOIGT-Lifter is for example the flare gas drain or
the delivery of process liquids, which are easily
inflammable.
Does a VOIGT-Lifter work
continuously?
This question couldn’t be
answered clearly.
Do I need special
personnel for the installation of a VOIGT-Lifter?
The VOIGT-Lifter is a
pure mechanical delivery unit.
Why is the VOIGT-Lifter so reliable?
All building and
functional components of a VOIGT-Lifter are appropriate for
a maximum load, which practically cannot be exceeded during
an intended use.
Which performance ranges
are covered by VOIGT-Lifters?
The VOIGT-Lifter is
manufactured in 8 sizes with a performance range from 1,2
m³/h to 20 m³/h. For higher capacities it is also possible
to install several lifters in a row, trouble-free.
Why has the VOIGT-Lifter
no water level
Indeed there are products
of competitors, which still are equipped with glass water
level indicators. Their sense may possibly be to observe the
constant changes of level in the work space where there
practical use is however not recognizable.
How do I have to
dimension the collecting tank?
First a collecting or a
buffer tank is necessary to take up all arriving condensate
lines if these cannot be summarized totally or partly before
in separate collecting lines. From this results only a
certain minimum length of the collecting tank.
What certificates are
part of the delivery of a VOIGT-Lifter?
The VOIGT-Lifter is
designed, manufactured and tested according to the Pressure
Equipment Directive (PED: 97/23/EC) or according to the ASME
Codes and Standards, confirmed by a certificate about the
NB-single-inspection. From case to case other national
standards may find use as well or alternately like IBR
(Indian Boiler Regulation) or GOST-R (Russian Certification)
and others.
What are the advantages
of a VOIGT-Lifter compared to pumping systems?
Usually pumps work
intermittent, i.e. the pumps deliver from very large
collectors between a maximum and minimum container water
level in pre-determined intervals.
Why is a VOIGT-Lifter
temperature-resistant?
The VOIGT-Lifter does not
possess mechanical or particularly sealed construction units,
which are subjected to close tolerances.
Where are the limits of
the appliance of a
Generally the appliance
of the VOIGT-Lifter is limited to the compliance to the
prescribed basic conditions (suction head, necessary
pressure of the working medium).
Why is the VOIGT-Lifter
so favourable for
For the assembly of a
pumping unit, different trades and suppliers are necessary,
whereby additionally planning , assembly , coordination and
start-up expenditures arise. This analogously affects
negatively the clarity of the plant and the range of the
documentations and not least applies on all questions of
guarantee.
Why is a lying work space
not used generally?
A professional condensate
technology has to be based technically and economically on
an optimum. |