SELF-VALIDATING ROTARY PADDLE BIN MONITOR

BULLETIN 253

Imagine a bin level sensor that is more than just an indicator of the presence or absence of material. Picture technology that allows inteligent devices to indicate when something is wrong. Dream that a level sensor provides real-time information when the quality of the sensor function no longer allows it to operate as you expect. That is a “self-validating” bin level indicator. Now you can wake up, your dream has arrived. Costly overfilling and outages due to sensor failure can now be avoided!

The SafePoint® self-validating bin level monitor is the state-of-the-art in rotary paddle technology. Going beyond traditional fail-safe sensor technology that only protects against power failure, the SafePoint bin monitor is the most reliable, rotary paddle point level control sensor available.

The SafePoint bin monitor provides the ultimate in performance wherever critical continuous operation must be ensured. Detection of both material presence and its own operational status is performed on a continuous basis.

The SafePoint level sensor monitors its electrical and mechanical operating condition. This, in conjunction with separate outputs for material sense and unit status (fault conditions) make the SafePoint a self-validating device.

Principle of Operation

While the SafePoint bin monitor is an evolution in rotary paddle technology, it continues to use tried-and-true operating techniques. Unlike many other available units, the SafePoint incorporates a feature that automatically shuts off its motor when the paddle is in a stalled condition. This extends the life of the unit and minimizes maintenance.

The operation of the SafePoint® rotary paddle bin monitor uses patented technology to detect material presence and operational status of the unit. The unit is installed through the wall of the vessel so that the paddle protrudes inside the vessel. A small electric motor drives the paddle, which rotates freely in the absence of material.

The rotation of the unit’s shaft is continuously monitored by detection of a magnetized rotating disk. When the paddle is impeded by material, the shaft rotation stops. The motor rotates within the housing and magnetized sections of the motor mounting plate are detected. Use of these patented magnetic sensing techniques eliminates problems that occur with fouling of the optical systems used by other brands.

The built-in microcontroller performs self-validating diagnostics and monitors both shaft and motor mounting plate rotation. This allows the SafePoint to easily distinguish between material presence and any electrical and mechanical failure of the unit. When material presence is detected, the SENSE relay changes state and the drive motor is de-energized to extend motor life. This output is available to control a process function or alarm circuit. When the material level drops, a tension spring returns the drive motor to its original running condition and is reactivated.

A unit failure is detected by sensing a lack of shaft rotation while material presence has not been detected by rotation of the motor mounting plate. In a failure condition the independent FAULT relay will change state. Monitoring the state of both the SENSE and FAULT relays provides the most flexibility for control and monitoring that is beyond being just “fail-safe”.

Applications

The rugged and reliable fail-safe design of the SafePoint® bin monitor makes it the best choice for critical level control applications. The unit is compatible with many granular, pelletized and powder bulk applications. It can be utilized for high level indication of materials over 10 lb/ft³ (160 kg/m³ ) and for low and intermediate level indication for materials over 5 lb/ft³ (80 kg/m³ ). The SafePoint bin level monitor can be installed almost anywhere dry bulk materials are stored including bins, hoppers, silos and tanks.

Features

Available Configurations

Accessories

PADDLE ASSEMBLIES
Monitor offers a variety of interchangeable paddle assemblies to meet the needs of a wide variety of applications. Different material densities, particle sizes and flow characteristics require specific paddles to provide optimum performance. See the paddle selection guide for more detailed application recommendations.

Dimensions are shown in inches with millimeter equivalent in brackets.

1.) Standard Stainless Steel Three Vane Paddle: The most popular of all paddles. For use with average weight materials. P/N 1-4146
2.) Large Stainless Steel Three Vane Paddle: Provides accurate level control for lightweight materials. P/N 1-4141
3.) Insertable* Stainless Steel, Scimitar Single Vane Paddle: Provides low and high level control for light to average weight materials. P/N 1-4193
4.) Insertable*, Stainless Steel Single Vane Paddle: Provides low level control for average weight materials and low to high level control for heavy materials under 1-1/2 inch (40 mm) in diameter. P/N 1-4145
5.) Stainless Steel, Two Vane Paddle: Provides low and high level control for heavy materials under 1-1/2 inch(40 mm) in diameter. P/N 1-4135
6.) Stainless Steel Four Vane Paddle: For use with average to heavy weight materials in low and high level control installations. P/N 1-4156
7.) Stainless Steel Triangular Arc Single Vane Paddle: Provides low and high level control for light to averageweight materials. P/N 1-4144
8.) Ex-Flex Three-Ply 20 inch (508 mm) Belt Vane Paddle: Provides low and high level control for heavy materials over 2 inch (50 mm) in diameter. Top mount only. P/N 1-4137
*Insertable paddles eliminate the need for a mounting plate. 1-4193 is insertable through either a half or full 1-1/4” or 1-1/2” coupling, that is welded to the bin wall. 1-4145 is insertable through a half 1-1/4” or 1-1/2” coupling.
FLEXIBLE COUPLING The flexible coupling works to absorb heavy loads, side loads and loads caused by product surges, thus protecting the internal workings and extending the life of the paddle unit. A flexible coupling should be used with heavy materials and in top mount installations where a solid shaft extension is used. Monitor offers the following coupling option: Spring-Flex: P/N 1-3335

MOUNTING PLATES
Mounting plates allow the paddle units to be mounted from the outside of a vessel to curved or flat surfaces. All mounting plates featured below mount via six bolts.

1.) Half Coupling Mounting Plate: For use in side mount installations. Available in powder coated carbon steel for general purpose applications and stainless steel for use in corrosive environments. Stainless Steel Plate: P/N 1-0112. Carbon Steel Plate: P/N 1-0101 for 1-1/4” NPT connection and P/N 1-0100 for 1-1/2” BSPT connection.

2.) Full Coupling Mounting Plate: For use in top mount installations where a shaft extension and shaft guards are required. Available in powder coated carbon steel for general purpose applications and stainless steel for use in corrosive environments. Stainless Steel Plate: P/N 1-0113. Carbon Steel Plate: P/N 1-0102 for 1-1/4" NPT connection and P/N 1-0115 for 1-1/2" BSPT connection.

3.) K-Flange Aluminum Mounting Plate: For flat surfaces or thin walled vessels where extra strength is required. Ideal for semi-corrosive environments, including outdoors. P/N 1-3316.

SHAFT GUARDS
Shaft guards are recommended for use with solid shaft extensions to limit the movement caused by side loading that would otherwise damage the working components of the paddle unit. Shaft guards should be the same length as the extension and should always be used when the extension meets or exceeds 18 inches (460 mm) in length.

Specifications

*Influenced by mounting, material thermal conductivity and ambient temp.

Warranty

Monitor Technologies LLC warrants each SafePoint® rotary paddle bin indicator 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.

U.S. PATENT 6,696,965 B2

DOC-000-253A
Rev.7.10032008

SiloPatrol^® SE
Inventory control of raw materials for pre-blended masonry products….

A company in Crystal Lake with 13 silos who provides pre-blended masonry products and automated mixing stations to construction sites or as they like to call it “mortar at a push of a button” was looking for a way to better control the inventory levels of their raw materials instead of having to do a “visual”. They are very proactive in trying to find ways to make themselves more cost-efficient and effective on all levels of operation. After some research they decided to go with the SiloPatrol® cable-based smart sensor (SMU) with the SiloTrackTM inventory management software from Monitor Technologies. Even though the system cost more than they initially were willing to spend, they were able to justify the expenditure because of the added benefits of time saved to manually measure the material levels and for the personnel safety reasons. Now with automatic or on-demand readings, they have better control of when they need to re-order raw materials and when the silos are getting full during refilling to prevent the downtime and clean-up costs of an over-filled silo. Plus, personnel make a lot fewer trips up the silos.

Their initial purchase was for 6 SMU’s and the SiloTrack software. Once they realized the value of the continuous level measurement system, they were able to justify the purchase of additional SMU’s for more of their silos.

Other features that they have come to appreciate about the SiloPatrol is the simplicity of installation (including wiring and set-up) for the sensor and the software, that the software works with the current PC on their desk, the sensor’s compartmental isolation of the electrical and mechanical components which eliminates much of the dust from going into the electrical area, and the ability to replace the sensor’s wiper and brush that cleans the cable without having to actually cut the cable for servicing. They also mentioned that technical support has been very responsive. They once had a computer board issue that caused software re-installation problems and technical support spent the time to talk them through the issue and shared knowledge for future prevention.

The SiloPatrol SE inventory management system is the second edition of the industry-leading cable-based smart sensor system that is designed to handle some of the harshest and most dynamic conditions imaginable. The SiloPatrol SE system incorporates state-of-the-art sensors with a wide choice of operator interfaces to fit all types of situations.

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.

>>Click here for more information about SiloPatrol SE from Monitor Technologies.
>>Download Product Bulletin 343A