Ash bed level control system for a fixed-bed coal gasifier
- Morgantown, WV
- Fairmont, WV
An ash level control system is provided which incorporates an ash level meter to automatically control the ash bed level of a coal gasifier at a selected level. The ash level signal from the ash level meter is updated during each cycle that a bed stirrer travels up and down through the extent of the ash bed level. The ash level signal is derived from temperature measurements made by thermocouples carried by the stirrer as it passes through the ash bed and into the fire zone immediately above the ash bed. The level signal is compared with selected threshold level signal to determine if the ash level is above or below the selected level once each stirrer cycle. A first counter is either incremented or decremented accordingly. The registered count of the first counter is preset in a down counter once each cycle and the preset count is counted down at a selected clock rate. A grate drive is activated to rotate a grate assembly supporting the ash bed for a period equal to the count down period to maintain the selected ash bed level. In order to avoid grate binding, the controller provides a short base operating duration time each stirrer cycle. If the ash bed level drops below a selected low level or exceeds a selected high level, means are provided to notify the operator.
- Research Organization:
- National Energy Technology Laboratory (NETL), Pittsburgh, PA, Morgantown, WV (United States)
- Assignee:
- United States of America as represented by United States (Washington, DC)
- Patent Number(s):
- US 4453949
- OSTI ID:
- 865043
- Country of Publication:
- United States
- Language:
- English
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Ash bed level control system for a fixed-bed coal gasifier
Ash level meter for a fixed-bed coal gasifier
Related Subjects
bed
level
control
fixed-bed
coal
gasifier
provided
incorporates
meter
automatically
selected
signal
updated
cycle
stirrer
travels
extent
derived
temperature
measurements
thermocouples
carried
passes
fire
zone
immediately
compared
threshold
determine
below
counter
incremented
decremented
accordingly
registered
count
preset
counted
clock
rate
grate
drive
activated
rotate
assembly
supporting
period
equal
maintain
avoid
binding
controller
provides
base
operating
duration
time
drops
exceeds
means
notify
operator
fixed-bed coal
level control
level signal
threshold level
bed level
temperature measurements
coal gasifier
coal gas
ash bed
bed coal
temperature measurement
selected level
ash level
automatically control
assembly supporting
drops below
level meter
selected threshold
clock rate
grate assembly
controller provides
temperature measure
bed stirrer
/48/422/700/