CEMLINE®
Unfired Steam Generators are designed to produce clean steam with steam
or high temperature hot water as an energy source for use where there
is a need to produce clean steam from boiler steam or high temperature
hot water.
CEMLINE Unfired Steam
Generators are constructed and stamped in accordance with ASME code
and bear the UB stamp as required by the ASME code. All vessels are
registered with the National Board of Boiler and Pressure Vessel Inspectors
and a compliance certificate is furnished. Unfired Steam Generators
to generate steam 40 psig or greater will be 100% X-Rayed and heat treated
in accordance the ASME code
CEMLINE Unfired Steam
Generators can be constructed of stainless steel when no condensate
is returned and there is 100% make up, such as in steam humidification.
A stainless steel USG would also be used to provide steam for sterilizers,
food processing, pharmaceutical, and clean room applications where deionized
or reverse osmosis water is used as feedwater.
CEMLINE Unfired Steam
Generators can be constructed with a carbon steel shell and steel components.
These Unfired Steam Generators would typically be used when the condensate
is returned to the boiler and there is little or no make up water. Carbon
steel Unfired Steam Generators are typically used in building heating
systems and in humidification where the feed water is not corrosive.
CEMLINE Unfired Steam
Generators are furnished with 3" thick fiberglass insulation. This high
quality insulation is an extremely reliable means of minimizing heat
loss.
CEMLINE Unfired Steam
Generators are neatly and attractively covered with a 20 gauge steel
jacket over the fiberglass insulation. The jacket protects the insulation
and is professionally painted with superior quality enamel which provides
an easy to maintain surface.
CEMLINE
Unfired Steam Generators are mounted on a structural skid designed as
a permanent base. This skid is pre-engineered to allow correct support
for the Unfired Steam Generator.
CEMLINE
Unfired Steam Generators are provided with one or more ASME Section
I pressure relief valve(s) sized to relieve the total BTU input of the
heating coil.
U-bend
coils are constructed with copper, copper nickel, or stainless steel
tubes. The selection of tubing material depends upon specific job requirements.
The sizing section of this interactive catalogue will assist in selecting
the correct tubing material.
CEMLINE
Unfired Steam Generators are furnished with an adjustable high pressure
cut off wired to close the control valve in the event of over pressure.
The high pressure cut off also has an adjustable differential.
CEMLINE
Unfired Steam Generators are furnished with a combination feed water
control/ low water cut off. This level control will allow the correct
water level to be maintained in the vessel and will also shut the generator
down in the event of low water.
As the
boiler makes steam, it is necessary to replenish the boiled off water.
A solenoid valve, which opens and closes from the water level controller
signal, is required. A solenoid feed system requires the feed water
pressure must be at least 10 psi greater than the steam pressure in
the Unfired Steam Generator. If there is less than 10 psi pressure differential,
a feedwater pump must be used. A check valve is supplied between the
solenoid valve and the unfired steam generator.
CEMLINE
Model 2001 Solid State Steam Control Module incorporates operating and
limit functions in one solid state controller. The controller features
a LED display of the pressure and on board settings of high and low
pressure safety cut off and alarms. The 2001 SSCM simplifies the control
of the Unfired Steam Generator, enhances the look of the product, and
follows industry trend to solid state controls.
An alarm
bell is furnished to sound an alarm in the event of either low water
or high pressure. An alarm silencing relay allows manual pressing of
a button to silence the alarm bell, but red warning light remains on
until the alarm condition is corrected.
This feature
allows the Unfired Steam Generator to be started or stopped from a remote
location. Typically this would be accomplished from the Building Automatic
Control (BAC). Requires a dry contact suitable for 24 Vac and 1 amp.
The alarm horn will
sound and fault LED will light on low water or high pressure. If either
high water or low pressure options are selected the alarm horn will
also sound in the event of high water or low pressure. The 2001 Solid
State Control Module also features an alarm silence relay which will
silence the alarm but not the fault light when the generator is being
serviced. When the fault is cleared, both the alarm and fault light will
automatically reset.
The CEMLINE 2001
Solid State Control Module operates in conjunction with the level control
to signal the feed water solenoid or feed water pump to maintain the
correct water level in the unfired steam generator.
The 2001 Solid State
Control Module is designed for the user to tell at a glance how the
system is operating. The built in LED displays make troubleshooting
simple.
This control
allows for simple and reliable interface with the BAC via dry contact
closures so the BAC can monitor the unfired steam generator from a
remote location. The BAC can also start and stop the unfired steam
generator.
A pilot operated
valve can only be used with steam as the energy source. Pilot operated
valves use steam pressure as the energy to modulate the control valve.
Steam from upstream of the valve is directed into a pilot valve. This
pilot valve has an adjustable set point and pressure sensor sensing
generated steam pressure. The pilot valve compares the set point to
the sensed pressure and regulates the amount of steam passing through
the pilot to the diaphragm in the bottom of the control valve. The
steam pressure on the diaphragm opens the valve. A pilot operated
valve has a constant bleed line leading from the diaphragm to the
downstream side of the valve. When the pilot valve senses that the
desired pressure is reached it closes; this does not allow any more
steam to pressurize the diaphragm in the bottom of the control valve.
The bleed line allows any steam pressurizing the diaphragm to be relieved
and the valve closes. In the event of high pressure or loss of building
power the limit control closes the steam line from the pilot to the
valve which closes the valve. With a supply pressure of up to 15 PSI,
3 PSI is the minimum pressure drop permitted across the valve. With
a supply pressure from 16 to 31 PSI, 10 PSI is the minimum pressure
drop permitted across the valve. With a supply pressure from 31 PSI
and above, 20 PSI is the minimum pressure drop permitted across the
valve.
Air operated valves
are normally used in building when building control air is available.
Air operated valves use building control air pressure to modulate
the control valve. The air signal is brought to an adjustable set
point pressure sensing controller sensing generated steam pressure.
The pressure sensing controller compares the set point to the sensed
pressure. The controller regulates the amount of air that passes to
the pneumatic actuator of the valve to modulate the valve. This allows
steam to pass into the unfired steam generator coil to maintain the
set point of the controller. When the set point is achieved, no air
is passed through the pressure sensing controller and the valve is
closed. In the event of high pressure or loss of building power, the
limit control will close the air line to the valve and vent any air
to the actuator to atmosphere which closes the valve.
Electronically
operated control valves use a solid state pressure sensor which is
wired to an electronic control module. The electronic module has an
adjustable set point. The control module compares the set point with
the sensed pressure and sends an electric signal to a magnetic linear
actuator on the control valve. The magnetic linear actuator modulates
the control valve and regulates the amount of steam through the valve
to maintain the set point of the controller. When the set point is
achieved, the controller sends a signal to the valve actuator and
the valve closes. In the event of high pressure or loss of building
power, the limit control closes the electric power to the controller
which closes the valve.
CEMLINE provides
float and thermostatic traps for both the drip and main trap. Float
and thermostatic traps are acknowledged as the correct traps to use
with continuously modulating control valves. Float and thermostatic
traps provide immediate drainage of condensate and include a built in
thermostatic air vent for venting air. The drain orifice is designed
to provide a water seal and eliminate the loss of any live steam under
all load conditions. Float and thermostatic traps should not be used
to lift condensate.
As the
boiler makes steam, it is necessary to replenish the boiled off water.
This method feeds the water from a boiler feed pump unit with a condensate
tank. The condensate tank is fed with make up water and condensate.
It operates on a signal from the level controller on the Unfired Steam
Generator which starts a pump that feeds the make up water into the
Unfired Steam Generator. When the water level in the Unfired Steam Generator
is satisfied, an electrical signal from the level controller signals
the water feed pump to close. The feed water pump pressure must be 15
psi greater than the generated steam pressure. A solenoid valve and
check valve is supplied between the pump and the unfired steam generator.
As the
boiler makes steam, it is necessary to replenish the boiled off water.
This method uses a feed water pump which is connected to the make up
water line and is started and stopped from a signal from the level controller.
A solenoid valve and check valve is supplied between the pump and the
unfired steam generator.
Unfired Steam Generators using city water will build up an accumulation of minerals in the boiler. These minerals must be disposed by a blowdown system. The blowdown system can simply be a manual blowdown where the maintenance person would manually blow off for a set period of time for a set frequency. It is advantageous to offer an automatic blowdown system. The simplest automatic blowdown system is one that operates from timers. The CEMLINE 2001 SSCM has a built in interval and duration timer wired to a blowdown solenoid valve. The owner/operator can set an interval between blowdowns in a range from 1 to 160 hours and a blowdown duration range of 1 to 250 seconds. The automatic blowdown is a fairly simple system. The automatic timer blowdown requires the owner/operator of the Unfired Steam Generator to do some analysis to determine what duration and interval he/she wishes to have his blowdown occur. *Note: Most municipalities do not allow high temperature discharge directly into the sewer system. CEMLINE offers a type "CBO" centrifugal blow-off/condensate cooler which will receive the blow down, flash the blow down to steam, and cool the condensate going to drain.
There is a more sophisticated system, which samples the boiler water and blows the boiler down when the dissolved solids exceed the set point. This is a time sample method which measures the total dissolved solids by opening the blowdown valve for an adjustable time period and measuring the blow off for dissolved solids. If the total dissolved solid exceeds the trip point, the motorized valve will remain open until the fresh water make up dilutes the boiler water to a safe level of total dissolved solids. *Note: Most municipalities do not allow high temperature discharge directly into the sewer system. CEMLINE offers a type "CBO" centrifugal blow-off/condensate cooler which will receive the blow down, flash the blow down to steam, and cool the condensate going to drain.
The unfired steam generator is a distiller creating pure water in the form of steam and leaving behind the minerals and dissolved solids in the water inside the steam generator. As more steam is produced the concentration of minerals and dissolved solids increase inside the steam generator. The concentration of dissolved solids will increase in the water until saturation point is reached. Then, the water can no longer hold all of the dissolved solids and some begin to drop out of the water in the form of suspended solids forming sludge or scale on the tube bundle and vessel. Scale formation on the tube bundle will reduce the capacity of the unfired steam generator.
Higher concentrations of dissolved solids may bring about carry over of make-up water in the form of wet steam. As the total dissolved solids increase so does the surface tension of the water causing the steam bubbles to adhere to themselves making it more difficult for the steam bubbles to burst as they rise to the surface of the boiling water. Therefore, the concentration of dissolved solids tends to be increased at or near top of water level in the steam generator. Reducing the concentration of dissolved solids and suspended solids in the steam generator will provide the desired capacity and dryness of steam.
A Surface Blowdown can be used to remove dissolved solids from the steam generator. Automatic blowdown controls such as a TDS control or timed blowdown can be mounted at the surface allowing the removal of dissolved solids from the water in the generator. Typically surface blowdowns are performed more frequently than bottom blowdowns.
Higher levels of suspended solids may be found in harder make-up water conditions. Suspended Solids tend to collect in the lower part of the unfired steam generator and form scale on the tube bundle. Removal of these suspended solids can be accomplished by bottom blowdown.
Automatic Bottom blowdown controls can be mounted on the bottom blowdown.
CEMLINE
blow down/condensate coolers are designed to receive blow down from
a steam boiler, flash the blow down to steam, and cool the condensate
going to drain.
In
some unusual situations, it is possible for the feedwater to fail which
could cause the Unfired Steam Generator to fill with water and flood
the entire system. To prevent this from happening, CEMLINE CORPORATION®
offers, as an option, a high water cut-off to close a feedwater ball
valve if a high water condition occurs. This option consists of a level
control connected to a high level switch. The high level switch will
send a signal to either an air operated ball valve or an electrically
operated ball valve mounted in the feedwater line. These valves are
power to open, spring to close
Air operated
valves are normally used in building when building control air is
available. Air operated valves use building control air pressure to
modulate the control valve. The air signal is brought to an adjustable
set point pressure sensing controller sensing generated steam pressure.
The pressure sensing controller compares the set point to the sensed
pressure. The controller regulates the amount of air that passes to
the pneumatic actuator of the valve to modulate the valve. This allows
HTHW to pass into the unfired steam generator coil to maintain the
set point of the controller. When the set point is achieved, no air
is passed through the pressure sensing controller and the valve is
closed.In the event of high pressure or loss of building power, the
limit control will close the air line to the valve and vent any air
to the actuator to atmosphere which closes the valve.
Electronically
operated control valves use a solid state pressure sensor which is
wired to an electronic control module. The electronic module has an
adjustable set point. The control module compares the set point with
the sensed pressure and sends an electric signal to a magnetic linear
actuator on the control valve. The magnetic linear actuator modulates
the control valve and regulates the amount of HTHW through the valve
to maintain the set point of the controller. When the set point is
achieved, the controller sends a signal to the valve actuator and
the valve closes. In the event of high pressure or loss of building
power, the limit control closes the electric power to the controller
which closes the valve.
A two way valve
modulates from fully closed to fully open varying the amount of hot
water circulated through the coil to maintain the desired output pressure.
When closed the two way valve may cause a change in the heating water
loop pressure.
A three way valve
modulates from directing all heating water through the coil to directing
no heating water through the coil, varying the amount of hot water
circulated through the coil to maintain the desired output pressure.
The pressure drop in the heating system will be relatively constant
with a three way valve.
As the
boiler makes steam, it is necessary to replenish the boiled off water.
This method feeds the water from a boiler feed pump unit with a condensate
tank. The condensate tank is fed with make up water and condensate.
It operates on a signal from the level controller on the Unfired Steam
Generator which starts a pump that feeds the make up water into the
Unfired Steam Generator. When the water level in the Unfired Steam Generator
is satisfied, an electrical signal from the level controller signals
the water feed pump to close. The feed water pump pressure must be 15
psi greater than the generated steam pressure. A solenoid valve and
check valve is supplied between the pump and the unfired steam generator.
As the
boiler makes steam, it is necessary to replenish the boiled off water.
This method uses a feed water pump which is connected to the make up
water line and is started and stopped from a signal from the level controller.
A solenoid valve and check valve is supplied between the pump and the
unfired steam generator.
Unfired Steam Generators using city water will build up an accumulation of minerals in the boiler. These minerals must be disposed by a blowdown system. The blowdown system can simply be a manual blowdown where the maintenance person would manually blow off for a set period of time for a set frequency. It is advantageous to offer an automatic blowdown system. The simplest automatic blowdown system is one that operates from timers. The CEMLINE 2001 SSCM has a built in interval and duration timer wired to a blowdown solenoid valve. The owner/operator can set an interval between blowdowns in a range from 1 to 160 hours and a blowdown duration range of 1 to 250 seconds. The automatic blowdown is a fairly simple system. The automatic timer blowdown requires the owner/operator of the Unfired Steam Generator to do some analysis to determine what duration and interval he/she wishes to have his blowdown occur. *Note: Most municipalities do not allow high temperature discharge directly into the sewer system. CEMLINE offers a type "CBO" centrifugal blow-off/condensate cooler which will receive the blow down, flash the blow down to steam, and cool the condensate going to drain.
There is a more sophisticated system, which samples the boiler water and blows the boiler down when the dissolved solids exceed the set point. This is a time sample method which measures the total dissolved solids by opening the blowdown valve for an adjustable time period and measuring the blow off for dissolved solids. If the total dissolved solid exceeds the trip point, the motorized valve will remain open until the fresh water make up dilutes the boiler water to a safe level of total dissolved solids. *Note: Most municipalities do not allow high temperature discharge directly into the sewer system. CEMLINE offers a type "CBO" centrifugal blow-off/condensate cooler which will receive the blow down, flash the blow down to steam, and cool the condensate going to drain.
The unfired steam generator is a distiller creating pure water in the form of steam and leaving behind the minerals and dissolved solids in the water inside the steam generator. As more steam is produced the concentration of minerals and dissolved solids increase inside the steam generator. The concentration of dissolved solids will increase in the water until saturation point is reached. Then, the water can no longer hold all of the dissolved solids and some begin to drop out of the water in the form of suspended solids forming sludge or scale on the tube bundle and vessel. Scale formation on the tube bundle will reduce the capacity of the unfired steam generator.
Higher concentrations of dissolved solids may bring about carry over of make-up water in the form of wet steam. As the total dissolved solids increase so does the surface tension of the water causing the steam bubbles to adhere to themselves making it more difficult for the steam bubbles to burst as they rise to the surface of the boiling water. Therefore, the concentration of dissolved solids tends to be increased at or near top of water level in the steam generator. Reducing the concentration of dissolved solids and suspended solids in the steam generator will provide the desired capacity and dryness of steam.
A Surface Blowdown can be used to remove dissolved solids from the steam generator. Automatic blowdown controls such as a TDS control or timed blowdown can be mounted at the surface allowing the removal of dissolved solids from the water in the generator. Typically surface blowdowns are performed more frequently than bottom blowdowns.
Higher levels of suspended solids may be found in harder make-up water conditions. Suspended Solids tend to collect in the lower part of the unfired steam generator and form scale on the tube bundle. Removal of these suspended solids can be accomplished by bottom blowdown.
Automatic Bottom blowdown controls can be mounted on the bottom blowdown.
CEMLINE
blow down/condensate coolers are designed to receive blow down from
a steam boiler, flash the blow down to steam, and cool the condensate
going to drain.
In
some unusual situations, it is possible for the feedwater to fail which
could cause the Unfired Steam Generator to fill with water and flood
the entire system. To prevent this from happening, CEMLINE CORPORATION
offers, as an option, a high water cut-off to close a feedwater ball
valve if a high water condition occurs. This option consists of a level
control connected to a high level switch. The high level switch will
send a signal to either an air operated ball valve or an electrically
operated ball valve mounted in the feedwater line. These valves are
power to open, spring to close.
SOLID
STATE CONTROL MODULE SSCM 2001