DOPPLER I & II Silo Level Gauges

Silo Level Indicators With High & Low Level Alarms.

doppler controls
REDUCES DOWN TIME
REDUCES SILO CONE DAMAGE*
REDUCES MIX WASTE
REDUCES MIX SEGREGATION
$ SAVES MONEY $

*Low level audible alarms alert the operator of a near empty silo condition. When trucks are loaded at near empty silo, cone wear is extremely accelerated.

Doppler - How It Works

An asphalt mix silo is a very hostile environment for any transducer. Up until the development of Doppler III software and transducer, ultrasonic systems were not capable of performing the hot mix asphalt silo application.

A Doppler Silo Level Gauge is an ultrasonic, non contact level indicator that reads in tenths of a foot. The instrument display panel can also be programmed to display the level readings in tons. The system can then be programmed to set high and low level audible alarms at adjustable set points.

The transducer sends a frequency signal through the air/gas from the top of the silo toward the gate in the silo bottom. This signal bounces off the silo gate or the material on top of the gate, and is returned to the instrument display panel. The time it takes for this signal to make the round trip back to the transducer is used to calculate the distance from the top of the silo to the top of the material in the silo. Temperature variations of the air inside the silo will effect the speed of the signal, but the Doppler system is capable of measuring the silo air temperature and is able to recalculate the distance accordingly. The Doppler Silo Level Gauge system is extremely accurate.

The level of material (in tenths of a foot) can be converted into tons. The conversion is a simple two step process. First the cone height and the net weight of material in the cone are entered into the instrument display panel. Secondly, the barrel height and the net weight of material in the barrel are then also entered into the display panel. The Doppler system is then able to accurately confirm the level of material in the silo, and produce the readout in tons. The display is set to continuously readout the silo level from the last reading it established. The display panel can also be set to make these readings at time intervals of your choosing.

doppler control panel

Improve Your Mix Quality, Inventory Control and Silo Maintenance.

When a plant is run with a full silo, the batcher (gob hopper) mix does not have a great enough distance for the mix to spread out evenly. The mix will thus cone up in a pile and the larger rocks will roll down the outside of the pile. By targeting the mid silo area for plant production and for truck loading the mix quality will be greatly improved. Doppler Silo Level Gauges will allow you to know accurately when the level in the silo will maximize mix quality.

When trucks are loaded and the silo is near empty, extreme wear will occur for two reasons. Mix is wearing out the liners as it slides down. The impact from the fall of the mix onto the cone liners also creates unnecessary wear. The explosion of the rocks due to the increased distance of fall from the gob drop, shoots the heavier particles (rocks) horizontally, creating more unnecessary wear and material segregation.

Truck Loading Practices.

All operators are conscientious about getting the trucks on their way. Loading out of the cone is a temptation many have trouble overcoming. Many operators however do not realize that only a few minutes out of each day may be lost if they hold up the first trucks until the silo bottom is filled to an optimal operating level, and remains sufficiently filled. 

An optional indicator light on the indicator display panel (TOO LOW TO LOAD) and a switch may be installed on the Doppler Silo Level Gauge, to help train operators to overcome the temptation to load out of the cone.

High & Low Level Alarms.

When using one of the set points as a high level alarm, a separate backup high level alarm is recommended. the backup alarm should be positioned so that the trip point is lower than the level it takes to submerge in the mix transducer (transducer hangs about a foot from the silo ceiling normally mounted close to the barrel wall). When using a gob hopper, high level alarm as a back up high level alarm it is recommended that the transducer cooling head be used.

Sometimes the return echo is lost. During loss of echo (LOE) the instrument display panel locks onto the last confirmed reading until the echo reading returns. Dry, dusty aggregate incorrectly installed wiring misaligned transducer may cause this problem. Most problems can be diagnosed from the instrument display panel. Factory phone support is available during all business hours at no charge.

'Doppler' Silo Level Gauge

silo doppler

Tonka Bay Instruments - Silo Level Gauge
Clarence Richard Company
3624 Sussex Place, Minneapolis, MN 55345
800-372-7731 FAX 612-938-3304
E-Mail: crco@crco.net Web: www.crco.net

Can readout in feet, tons, yards, etc.
With High /Low Alarms
Easy Installation

DOPPLER I AND II --SILO LEVEL GAUGE

Doppler II ultrasonic is the cutting edge of this technology. It is new on the market. The first was started up in the Spring of ‘98 .

An asphalt mix silo is a very hostile environment for any transducer. Up till the development of Doppler III software and transducer, ultrasonic systems were not capable of performing the hot mix asphalt silo application.

Is an ultrasonic, non contact level indicator reading in tenths of a foot. The Instrument Display Panel can calculate and display the level reading into a tons reading. The Instrument Display Panel is capable of alarming at adjustable set points. The transducer sends a frequency signal through the air (gas) from the top of the silo toward the gate in the silo bottom. The signal bounces off the silo gate or the material on top of the gate. The signal is received and the Instrument Display Panel. The round trip time it takes for the signal to return to the transducer is used to calculate the distance. Temperature variations in the silo air vary the speed of the signal. The Instrument Display Panel measures the temperature of the silo air.

Level (in tenths of a foot ) can be converted to Tons. The conversion becomes a two step process. The cone height and material net weight in the cone are entered into the Instrument Display Panel. Then the barrel height and the net weight of the material in the barrel are entered.

The Instrument Display Panel takes some time to confirm accurate material level. The unit displays the last confirmed measurement while thinking. The Instrument Display Panel tells you when it is thinking.

Doppler II can be used to * improve mix quality, * improve inventory control and * improve silo maintenance.

* When a plant is run with a full silo, the batcher (gob hopper) mix does not have a distance great enough for the mix to spread out evenly. The mix cones up in a pile and the larger rocks roll down to the outside of the pile. Mid silo is the target area to target plant production-truck loading to.

* When trucks are loaded when silo is near empty, extreme silo wear is occurring for two reasons. Mix is wearing out the liners as it slides down the liners. The impact from the fall onto the cone liners creates unnecessary wear. The explosion of the rocks from the gob drop from the increased distance, shoots the heavier particles (rocks) horizontally creating more unnecessary wear and material segregation.

Regarding truck loading practices; all operators are conscientious about getting the trucks on their way. Loading out of the cone is a temptation many have trouble over coming. Many do not realize that only a few minutes is lost for the whole day when they hold up the first truck until the silo bottom is filled and remains filled sufficiently.

An optional indicator light (READY TO LOAD) and switch may be provided to train operators.

When using one of the set points as a high level alarm, a separate backup high level alarm is recommended. The back up alarm should be positioned so the trip point is lower than the level it takes to submerge the transducer. When using a gob hopper, high level alarm as a back up high level alarm, it is recommended that the Transducer Cooling Hood be used.

Sometimes the return echo is lost (LOE - Loss Of Echo). During LOE, the Instrument Display Panel locks onto the last confirmed reading until the Echo reading returns. Dry, dusty aggregate, incorrectly installed wiring, mis aligned transducer, etc. can cause this problem. Most problems can be diagnosed from the Instrument Display Panel. Factory phone support is available free of charge. When calling, a phone near the unit is most helpful.

The transducer ‘s maximum temperature rated 300 degrees F. The temperature can be monitored from the Instrument Display Panel mounted in the control room. Applications where excessive temperature becomes a problem, Option 2 (Transducer Cooling Hood) should be used. The Optional Cooling Hood helps prevent the transducer from being submerged in mix and being damaged. Transducers cost about a third of the system.

When installing the transducer, the unit should be placed on top of the silo as close to the barrel edge as possible. Point the transducer directly at the nearest silo discharge gate opening. For best results, contact factory the factory before installing.

Instrument Display Pane -120 VAC…Transducer - one twisted pair of shielded, low voltage cable up to 200’ otherwise coax cable…depending on local EMF (Electro-Magnetic Frequency) noise - cable may have to be run in metal, grounded conduit.

Option - Transducer Cooling Hood - Customer to supply regulated air. Contact factory if compressed air is not available.

DOPPLER I - Single Silo Unit
With Alarms, Aimer and Short Ranger
$3495
DOPPLER II - Double Silo Unit
With Alarms, 2 Aimers and 2 Short Rangers
$5995
Short to Long Ranger upgrade $395 for each upgrade
Cooling Hood $245
Cable - double-shielded
Contact factory if over 200 feet
$1.00/foot

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