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MDS
E-SCAN Monitor Divert System
INTRODUCTION
 Since
1978, The Electron Machine Corporation has installed complete Monitor Divert
Systems protecting recovery boilers and personnel worldwide. The system is
designed to monitor black liquor solids to the recovery furnace and automatically
divert the liquor should the solids concentration fall below 58% or other
pre-selected point. This system greatly reduces the chance of smelt water
explosions caused by the introduction of low solids liquor into the furnace
through gun nozzles. This latest system, model MDS E-Scan, is a third
generation unit employing microprocessor circuitry to do a comprehensive
check of all the operating functions of two independent refractometers. The
system meets or exceeds the recommendations of the Black Liquor Recovery
Boiler Advisory Committee (BLRBAC). The Electron Machine Corporation
has placed more than 30 years of refractometer experience into the development
of the MDS E-Scan Black Liquor Divert System. Using the newest CCD electronic
scanning technology, hence E-Scan, coupled to an easy menu-driven 386 processing
unit, it provides an accurate and reliable liquor solids measurement.
DESCRIPTION
The MDS E-Scan consists of two MPR E-Scan microprocessor-based
refractometers each operating independently. A third processor supervises
the proper operation of each refractometer to insure it stays within operational
limits. It also contains alarm and divert logic to initiate the proper action
should a fault or low solids liquor be detected. A built-in printer records
all actions with a date and time stamp. All units have a large transmissive
LCD display with backlight for easy viewing and menu selection.
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OPERATION
 All
functions of the MDS E-Scan are automatic. For example, should a refractometer
fault occur the unit is electronically removed from service and an alarm
is activated. Simultaneously the output signal is driven low to warn the
operator to disregard this reading. The monitor system then isolates, displays
the fault and provides a hard copy record on the standard built-in printer.
Liquor diversion is now controlled by the refractometer still in service.
Many features are incorporated into the MDS
E-Scan. Besides providing a printout of all critical operations, the monitor
unit will data log error alarms, warning alarms, diverts, prism purge duration,
comparator readings, etc. This valuable information can be useful in both
preventive and predictive maintenance.
Special Features
- Intelligent purge function (This ensures proper cleaning
and extended prism life)
- Divert trending (Provides an actual time left before diversion
when liquor solids are getting low)
- Password protection (Used for critical software areas)
The MDS E-Scan monitor double checks all important
areas with microprocessor speed. Even the analog and digital output signals
are compared for accuracy.
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OUTPUTS
Standard output is a 4-20 ma for liquor concentration.
Relay contacts are used for liquor divert, alarms, and system error indicators.
A built-in printer is a standard feature for the MDS E-Scan. A remote divert
input line is also available. Consult the factory for hardware/software options
to suit your special requirements.
OPTIONS
Systems are complete and options are minimal.
OPTION (A)
A 316 stainless steel NEMA 4X console to house
the complete divert system with display windows and system switches. This
comes with a vortex cooler for hostile environments.
OPTION (B)
The RSP is a remote status panel containing
an LCD display with backlight which shows the current percent solids, liquor
temperature, and a 2-hour continuous solids graph for each unit. A dotted
line on the RSP indicates the divert point as a reminder when the solids
are low.
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