Monitor's line of microwave solids flow monitors
are high quality, industrial grade instruments capable of providing
a signal indicating the flow/no-flow condition of solids and
powders in gravity chutes, feeders and pneumatic pipelines.
The Model SFD-2 Solids Flow Detector provides relay outputs
that can be setup to indicate changes in the target flow stream
(on/off). The Model SFI Solids Flow Indicator provides an analog
output which varies with changing conditions of the material
flow stream. These non-contact monitors contain no moving parts
or probes that can wear out or break off in the material flow,
thus ensuring process integrity.
The SFD-2 and SFI use low
power microwaves to sense motion within the chute or pipeline
being monitored. Microwaves are virtually
unaffected by ambient noise and light, heat, humidity, pressure,
vacuum, high or low temperatures or dust. This provides maximum
effectiveness in typical industrial application environments.
These advantages over sonic or mechanical flow monitors make
microwave technology the best choice for solids flow monitoring.
Both the SFD-2 and SFI utilize a microwave transceiver
(combination transmitter/receiver) enclosed within a watertight,
dust-ignition proof powder coated aluminum housing with a screw-on/off
cover. A process seal (Teflon® or Ryton®) acts as a
transparent window through which the microwave energy is transmitted
and the reflected return signal is received. The transceiver
module generates and transmits a microwave signal into the
area where material flow is to be monitored. The reflected
microwave signal shifts in accordance with the Doppler Effect
phenomena. The Doppler-shifted energy is analyzed to determine
the appropriate output from the unit.
The SFD-2 has a split-architecture
design consisting of the transceiver and a separate power
supply/conditioning circuit board. The relays
are incorporated on the power supply/conditioning circuit board,
which is optionally available with a fiberglass enclosure and
indicating lights. With the SFD-2, the Doppler-shifted energy
signal from the transceiver is carried back to the power supply/conditioning
circuit board through the user-supplied signal and power supply
cable. At the power supply/conditioning circuit board the signal
intensity is indicated with an LED and converted into a relay
output based upon the sensitivity adjustment. The power supply/conditioning
circuit board provides the power to drive the transceiver and
contains the controls for setting sensitivity, hold-off time
delay, hold-on time delay and fail-safe selection.
The SFI
Solids Flow Indicator, unlike the SFD-2, consists solely
of a transceiver. In this case the transceiver will receive
its DC power through the user supplied signal cable and power
supply.
The three-wire design allows the user to monitor the analog
output while providing the supply power to the unit. The
Doppler-shifted
energy is relative to the magnitude of the flow/no-flow condition
that exists, when material velocity is constant, and this
is reflected in the varying analog output signal.
Applications
Monitor's Solids Flow Detector and Indicator can
be used in a variety of applications to detect flow/no-flow
conditions of powders and solid materials. The selection of
either SFD-2 Solids Flow Detector or the SFI Solids Flow Indicator
is based upon the type of output required (relay or analog).
Detection of a partial or full plug in a conveying line
Detecting the bridging of material in a storage vessel upstream
Sensing inadequate or a lack of flow due to upstream equipment failure (conveyor, blower, diverter valve, feeder)
Verifying flow conditions
Turning on/off equipment or processes downstream
Use of SFI Analog Outputt
The Model SFI Solids Flow Indicator can be used to infer the
relative amount of flowing material within the target conduit
(by monitoring the available analog signal). However, it
should be noted that this device provides an output that
should be considered, at best, a very rough estimate of the
flow of material. The analog signal corresponds to the magnitude
of the Doppler-shifted energy created by the flow of material
through the microwave energy field.
Note:Monitor Technologies
LLC accepts no responsibility for the accuracy of the analog
output signal. This signal can be
influenced by several varying factors including, but not
limited to, particle size distribution, dielectric constant
variation,
moisture content variation, dispersion of material flow,
variation in velocity of material flow, movement of auxiliary
equipment,
temperature variations and type of conveying system. Please
consult the factory to discuss applications where the accuracy
of the analog output is of importance.
Pictured at the right
is a SFI installed in a plant that manufactures ink for desktop
printers and copy machines. 100-pound batches
of carbon black come out of a feeder and are pneumatically
conveyed through a four-inch vertical line. The SFI is
used to indicate when a batch of carbon black has cleared the
line.
Connects
to transceiver using an inexpensive, low voltage 3-wire
system
Convenient
control functions for time delay, sensitivity and fail-safe
selection
Control
function changes can be made without accessing the transceiver
Yellow
and Red LEDs indicate material flow intensity and output
activation
Options
RYTON® PROCESS SEAL
Both the SFD-2 and SFI come standard with a Teflon® process
seal window through which the transmit/receive signal passes.
While this material is compatible with most applications, a Ryton® seal
is available for use in applications where the seal is subjected
to high pressure or abrasive materials.
ENCLOSURE FOR CIRCUIT
BOARD (SFD-2 only)
The standard SFD-2 does not provide
an enclosure for the power supply/conditioning circuit board.
This allows the user to install the board wherever is appropriate.
A NEMA 4X enclosure is available. When selected, the power
supply/conditioning circuit board is supplied installed within
a fiberglass enclosure furnished with long-lasting LED
indicators flush with the enclosure face.
Left: Power Supply/Conditioning Circuit Board
Right: Optional Enclosure
Accessories
GALVANIZED HALF-COUPLING
Monitor provides a galvanized half-coupling which can be welded
to the chute or pipe for mounting the transceiver. Half Coupling:
P/N 17-3111
LOCKNUT
The optional locknut provides flexibility in the depth of
the mounting of the transceiver to ensure that the process
seal is
flush with the inside of the conduit in which the target material
flows. Lock Nut: P/N 17-3000-7C
SADDLE COUPLING
The saddle coupling provides a means of mounting the transceiver
without welding a mounting coupling. The saddle coupling,
which includes a gasket, is suitable for round chutes 4-10" (102-254mm)
in diameter and can be easily clamped to the chute or pipeline.
Saddle Coupling: P/N 17-3102-1
STAINLESS STEEL ADAPTERS
Four different mounting adapters can be used to provide a
stainless steel process contacting surface. The adapter
can be of either
1-1/2" NPT or Tri-Clamp® food grade construction.
1-1/2" NPT: P/N 17-3303-1 (Teflon® seal) P/N 17-3303-3
(Ryton® seal)
Tri-Clamp: P/N 17-3305-1 (Teflon® seal) P/N 17-3305-3
(Ryton® seal)
Specifications
TRANSCEIVER
(SENSOR)
Power
Requirement:
SFD-2:
Provided
by power supply/conditioning PCB
SFI:
15-30VDC,
100mA max.
Enclosure:
Die-cast
aluminum, beige polyester powder coated
Enclosure
Protection:
NEMA
4, IP66
Ambient
Operating Temperature:
SFD-2:
-40° to
+185° F (-40° to +85° C)
SFI:
-13° to
+185û F (-25û to +85û C)
Process
Temp. Max:
250°F
(121°C) if ambient air temp. below 150°F
(65°C)
Process
Seals:
TFE
Teflon®, Ryton®
Pressure
Ratings:
TFE
Teflon® (75 PSI intm), Ryton® (300 PSI)
Process
Connection:
1
1/4" NPT (1-1/2 w/ SS Adapter)
Conduit
Connection:
(2)
1/2" NPT
Detection
Range:
0
to 10' free air, env. and target dependent
Sensitivity:
Switch
selectable HI/LOW
Minimum
Velocity:
2.5
ft/sec (762mm/sec)
Output:
SFD-2:
None,
signal from transceiver is delivered to and processed
by power supply/conditioning circuit board
SFI:
4-20mA
output typical (full span may not be achieved; actual
span is application dependent)
Isolation
(SFI Only):
750
VPK isolation between sensor ground and user power
supply/analog supply
Indicators:
Green
LED – power; Yellow LED Ðloop, intensifies
with disturbance detected
Emission:
24.125
GHz, FCC & IC certified, energy levels less than
1mW/cm(2) (OSHA limit at 10mW/cm(2))
Approvals:
CSA(us/c), Class II Div. 1 & 2 Groups E, F & G
CE Mark (Ordinary
Location)
POWER
SUPPLY/ CONDITIONER BOARD (SFD-2 ONLY)
Enclosure
(if supplied):
PBT/Polycarbonate
Enclosure
Protection:
NEMA
4X, IP66
Ambient
Operating Temperature:
-40°F
to 158°F (-40°C to 70°C)
Interconnection
Distance:
2500ft
max (minimum wire size 22 AWG)
Power:
Universal 100-240 VAC, + 10%, 50/60 HZ
Power
Consumption:
5
VA max
Output:
DPDT
dry contact, 5A @ 240VAC, 30 VDC
External
lights (if applicable):
Solid
state LED clusters
Yellow – material sense; Red – output operate
Sensitivity
Adjustment:
Single-turn
adjust 0 to 100% of sensor range
Time
Delay:
Hold-off,
single-turn adjustment, 0.25 to 15 sec.
Hold-on, single-turn adjustment, 0.25 to 15 sec.
Fail-Safe:
Switch
selectable, (Flow/No-Flow)
Indicators:
Green
LED - power; Yellow LED - sense; Red LED - output
Approvals:
CSA(us/c),
ordinary locations, industrial control equipment
CE Mark (ordinary locations)
Ryton® -
Trademark of Phillips Chemical Co.
Teflon® - Trademark of Dupont Chemical Co.
Tri-Clamp® - Trademark of Tri-Clover, Inc.
Warranty
Monitor
Technologies LLC warrants each SFD-2/SFI it
manufactures to be free from defects in material and workmanship
under normal use and service within two (2) years from the
date of purchase. The purchaser must give notice of any defect
to Monitor within the warranty period, return the product
intact and prepay transportation charges. The obligation
of Monitor Technologies LLC under this warranty is limited
to repair or replacement at its factory. This warranty shall
not apply to any product which is repaired or altered outside
of the Monitor Technologies LLC factory, or which has been
subject to misuse, negligence, accident, incorrect wiring
by others or improper installation. Monitor Technologies
LLC reserves the right to change the design and/or specifications
without prior notice.
813.3.1207
SiloPatrol® SE Measuring coal
powder levels when nothing else will work ….
Coal-fired power plants are commonplace around the
world. In order for these power generating stations to create
huge amounts of electricity the turbines need to be feed with steam
and the steam created by boilers that are fired by … yep,
coal. But coal as it comes from the mining operations is not
what is fed to the burners. First it is ground or pulverized
into powder. It is not unusual for the coal powder to be stored
in silos awaiting the demand for it to be fed to the burners. The
inventory of coal powder in these silos needs to be monitored to
allow for efficient operation of the power plant.
So, how do we monitor the inventory of coal powder in a silo? Not
easily. In one typical application the power plant personnel
found that the only technology that would work reliably is the modern
smart weight & cable system from Monitor Technologies LLC, the
SiloPatrol® SE.
Anhui
Tongling power plant in Anhui province in China had tried almost
ever technology possible to get a reliable level measurement in their
5 coal powder silos. Radar, ultrasonic and others were tried,
but none worked reliably. It wasn’t until Beijing Conasen
walked in and proposed that the Tongling plant use the SiloPatrol
SE smart cable-based inventory monitoring system that the power plant
personnel found a reliable solution.
Mr. William Yuan, sales manager for Beijing Conasen indicates that
the power plant tried many major brands of ultrasonic, radar, and
other technologies but that due to good relations with the Tongling
plant personnel he was able to sell three SiloPatrol SE model SMU
sensors and an HMI operator interface to them. The units were
installed by plant personnel. Because of the heavy amount of
coal dust in the silos an air purge using dry compressed air was
used. The SiloPatrol sensor incorporates the patent-pending
use of Hall-effect sensor technology, a split-compartment enclosure,
microcontroller, redundant optics and many other valuable features
and technology to ensure reliable measurement even in challenging
dust applications like coal powder.
The SiloPatrol SE system has been working reliably and the plant
has since purchased two additional sensors and connected them into
the same HMI operator interface. This same sensor technology
is working reliably at other coal-fired power stations in China as
well.
For more information on the SiloPatrol SE click
here or contact Monitor Technologies LLC at 800-766-6486 in the
USA and 630-365-9403 worldwide.