Product category:
Powder and Solids Handling
News Release from: Synatel Instrumentation | Subject: Step-a-Matic
Edited by the Processingtalk Editorial
Team on 17 March 2008
A novel rotating paddle type solids
level control
The Step-a-Matic is a patented rotary paddle solids point level probe using a new and unique gearless and clutchless drive system, providing much improved operational reliability
The Stepamatic utilises a direct drive stepper motor eliminating the need for gearboxes and clutches, and makes the drive virtually indestructible It also allows the motor to rotate in both directions, to avoid compaction of light material
This article was originally published on Processingtalk on 17 Mar 2008 at 8.00am (UK)
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Variable torque setting allows one paddle to suit virtually all applications, and paddles can be extended up to 2m in length.
Torque and rotation are monitored for fail-to-safe operation, and the probe can be inserted through a 1inch BSP threaded boss.
Rotating paddles are perhaps the most common method of point level detection and alarm in powder and solids silos.
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In their simplest form, they consist of a geared synchronous motor and clutch mounted on a spring loaded quadrant arm, which is in contact with either of two micro switches.
The motor drives a shaft fitted with a paddle.
When no material is present the arm is held against one micro-switch by the spring and the motor turns freely.
When material covers the paddle and jams it, the motor continues to turn forcing the quadrant arm to move against the spring away from the first micro switch, thus giving a "probe covered" signal.
The motor continues to rotate, eventually operating the second micro-switch which cuts motor power.
The system remains in this state until the level of material falls away from the probe.
The spring then pulls the quadrant arm back, reconnecting motor power and operating the first micro switch to indicate "uncovered".
The process then repeats.
The problem with this simple system is that should the motor / gearbox / clutch fail, the system will show a healthy state until the bin overfills.
This can be overcome by monitoring rotation of the motor using an electronic sensor.
Until the recent introduction of the Synatel Step-a-Matic, they have always contained a motor / gearbox and often a protective clutch in case the paddle is forced to rotate by passing material.
Gearboxes and clutches are frequently prone to failure.
The new patented Step-a-Matic paddle probe launched by Synatel uses a direct drive stepper motor connected directly to the paddle.
This eliminates both the gearbox and clutch making the product virtually indestructible.
It also allows paddle rotation both clockwise and anticlockwise to avoid compaction of material against bin sidewalls and the paddle also "shakes" to shed unwanted material.
Rotation and hence presence of material is detected by electronic circuitry.
Torque control allows a single paddle to be used regardless of material density and the unit will operate on virtually any supply.
The system provides reliable, fail safe operation for virtually any material and has a life expectancy running to decades.
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