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SAIMO
Pressure-resistant Gravimetric Coal Feeder
Model: F55
Saimo F55 Pressure-resistant Gravimetric Coal Feeder
is specially designed to continuously feed specific
amount of coal into large electrical utility and industrial
boiler. Precision and reliability are achieved by merging
Saimo latest in-motion weighing technology and the specially
designed digital controller. It is widely used for fuel
control, inventory monitoring and reporting for all
kinds of pressurized boiler applications in power plant,
chemical industry and coal mine. |
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| Theory
of Operation |
For typical coal powder boiler applications,
the coal feeder is usually mounted under the bunker to continuously
deliver the specified coal flow into the pressurized mill. The
coal feeder is connected to the bunker via an inlet chute to
allow positive coal loading on the belt of the coal feeder.
The two high precision strain gauge load cells positioned under
the weighbridge provide real-time coal weight as the belt loading
passes through the weigh area. Belt speed is continually measured
with a digital speed sensor whose pulse output is proportional
to belt speed. The speed sensor is mounted on the tail-pulley
to assure accurate belt speed measurement and detection of any
possible slippage.
The speed signal and weight signal are combined in the microprocessor-based
integrator totalizer which generates and displays a true-rate
signal in TPH and the total of material fed. A controller compares
the rate signal to the setup feed rate (set from a host computer,
PLC or by manual command) and generates the necessary output
signal to the frequency converter by means of PID regulation,
changing the feederĄ¯s belt speed to maintain the desired constant
rate of material fed. This in-motion adjustment operation ensures
continuous and constant coal feeding into the coal mill.
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| Features |
- Rugged pressure-resistant housing, tightly sealed to prevent
air and coal dust leaks, capable of withstanding 0.35Mpa
explosion pressure.
- Packing seal for all extruding shafts, ensuring pressure-resistant
performance.
- Plug-in slot design for the access doors, and blind hole
on the inspection port for effective sealing
- Seal air joint with multipoint exhaust structure for
efficient isolation from hot air.
- Flat idler construction, and endless corrugated belt
made of fireproof rubber with up to 40mm skirt-edge height.
- Powerful drive pulley lagged in rubber herringbone pattern,
preventing belt misalignment.
- Crowned driven pulley eliminating belt misalignment.
- Screw take-up device fixed outside the housing for belt
running in tension, reducing belt slippage and misalignment.
- An automatic belt deviation correcting device equipped
on the return belt for self-correction of belt misalignment.
- Pulleys supported by pillow block bearings with provision
for field re-lubrication outside the casing.
- Steel-surface cylindrical idler, 89mm in diameter, allowing
increased accuracy by reducing idler roller run-out.
- Gravity type scraper utilized for exterior belt cleaner
and V-shaped rubber scraper for interior cleaner.
- A chain scraper conveyor mounted at the bottom of the
coal feeder, removing flying dust.
- Access door installed on either side of the coal feeder,
and inspection port for easy maintenance.
- Several lamps mounted on the feeder body, with bulb easily
replaced without interrupting the process.
- A sliding guideboard adjustable for truing coal flow.
- Weighbridge supported on two load cells effectively compensates
for errors due to off-center loading
- Test weight calibration facility
- Speed sensor installed on the tail pulley minimizes the
error due to belt slippage.
- Premium weigh feeder controller based on 32-bit microprocessor
with a 20-bit A/D converter for quick and accurate operation,
as well as diversified inputs/outputs and communication
interfaces.
- Direct coupled, sprocket transmitted or shaft mount drives
available
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| Options |
- In-process Auto-zeroing (IPAZ) feature, ensuring high
precision
- Belt tension measuring system, ensuring accuracy and
belt rip detection
- Inlet gate valve, manual or automatic control selectable.
- Discharge gate valve Manual, rapid cut-off style, pneumatic
or electric control selectable.
- Customized inlet structure, in compliance with specific
requirements
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