Aggregates and Mining Today

VEGA is a global supplier and equipment provider to international cement producers and large plant builders. From conveyors to crushers to silos, VEGA offers premium solutions for a variety of measuring tasks. Undeterred by extreme operating conditions or large ranges, VEGA instruments can overcome all cement and aggregate measurement challenges with flying colors. Three VEGA devices are of particular interest in cement production.

WeighTrac 31

Reliable measurement for materials on the move
When it comes to cementitious materials, there’s a lot riding on conveyor belts. Users count on conveyors to effectively feed bulk aggregates to and from production processes. A reliable belt-weighing scale system and accurate mass flow rate ensures smooth, efficient plant operation. The WeighTrac 31 keeps material moving.

How it works
The WeighTrac 31 uses radiation to measure mass flow. A radiometric sensor consists of a sealed radioactive source in a source holder and a scintillation detector mounted on opposite sides of the conveyor. In some applications, the source is mounted above and the detector is mounted below, while in other applications the detector is mounted above and the source below. In either case, a fan-shaped, collimated radiation beam transmits from the source through the process material and the conveyor to the detector.

When the total mass per square foot on the belt or screw conveyor changes, the amount of radiation reaching the detector changes inversely. The greater the mass on the belt, the lower the radiation field at the detector. Conversely, the lower the mass on the belt, the higher the radiation field at the detector. The amount of radiation seen at the detector is thus inversely proportional to the amount of material on the conveyor, and this value is translated into an output signal from the detector.

Practical Application
Radiometric weight measurement works best with consistent medium-to-heavy loads and with conveyors from about 0.5 to 3.0 meters wide. Installation is relatively simple as the instrument is usually supplied with a frame that mounts directly to the conveyor. The WeighTrac 31 can be mounted on inclined conveyors without affecting measurement, and it can be relocated with minimal effort.

Radiometric mass flow measurement technology has proven very reliable because it operates without touching the material. Non-contact measurement systems like the WeighTrac 31 are nearly invulnerable to the vibration common to conveying applications, and radiometric measurement is unaffected by temperatures up to 140° F (60° C). Electronics are typically built into the instrument to compensate for additional variables such as belt or screw speed, and to convert the measurement into a total weight or a weight-per-time period output.

Summary
Radiometric measurement devices like the WeighTrac 31 provide an extremely stable mass flow solution with little required maintenance. Measurement precision is about ±1%, and accuracy is unaffected by process conditions such as dust, corrosion, and temperature changes. By and large, users can set it and forget it when it comes to the WeighTrac 31. The non-contact device provides a solid state measurement, greatly reducing required maintenance over other mass flow measurements.

VEGAPULS 69
Level measurement when every inch counts
The cement industry is thick with silos and other vessels used for the production and storage of materials. In order to maximize the silos onsite, users need a level measurement device that flourishes under difficult process conditions, responds to challenging angles with excellent focus, and measures the most unreflective materials. The VEGAPULS 69 radar sensor for bulk solids fits the bill.

How it works
In radar level measurement, the antenna system of the sensor transmits short microwave pulses to the measured product. These signals are reflected by the product surface and sent back to the antenna system. The time from signal emission to reception is proportional to the level in the silo in that the faster the signal returns, the fuller the silo.

Practical Application
The interior of a storage silo is often dusty, and abrasive materials tend to generate buildup that can disrupt level measurement. Combine that with the fact that level devices are often subject to wind, rain, and other harsh weather conditions, and it’s no wonder that users need a special sensor to hold up to the internal and external abuse. The VEGAPULS 69 gets high marks for durability.

Unaffected by intense dust generation, buildup, and changing temperatures, the non-contact radar sensor is reliable in silos, crushers, and conveyor transfer stations. Due to its industry-leading 80 GHz transmission frequency, the VEGAPULS 69 emits an ultra-focused radar beam so it reliably receives a clear signal, even when installed at difficult angles. Finally, the VEGAPULS 69 includes the latest sensitivity software for level measurement of bulk solids that struggle to reflect radar signals.

Silo height has historically been a deterrent to using radar sensors for level. After all, who wants to volunteer to climb a narrow staircase to the top of a tall vessel to adjust a sensor? What if it’s raining or snowing? Who wants to go up under those circumstances? Users who install the VEGAPULS 69 don’t have to worry about risking physical harm because the instrument includes optional Bluetooth technology that allows for wireless adjustment. From over 80 feet away, a smartphone or tablet can access the sensor, improving safety and convenience.

Summary
Cement and aggregate silos are difficult environments that demand a durable level measurement sensor. With virtual immunity to extreme weather and abrasive process conditions, the VEGAPULS 69 is a reliable level solution. High focusing and sensitivity make it compatible with a variety of materials and opting for Bluetooth technology ensures safety for plant personnel. In total, the VEGAPULS 69 is the ultimate solution for cement and aggregates level measurement.

VEGA Inventory System
For informed material management
Historically, reliable and cost effective real-time inventory monitoring in silos has been lacking. This deficiency has led to the standard practice whereby perpetual inventory, instead of real-time inventory, is used as the basis for decisions within a ready-mix operation. Perpetual inventory relies on prompt and accurate recording of all incoming raw materials and all outgoing product, a process that often proves difficult because, generally, the personnel responsible for entering inventory figures is busy operating the plant and making concrete. This means many production decisions are based on inaccurate information, and plants develop less-than-optimal work processes to compensate for the inaccuracy.

As the construction industry continues to grow, it faces many challenges including the constant pressure to reduce costs, an ongoing driver shortage that stretches resources, traffic that bottlenecks routes, and more loads to deliver on longer hauls. Companies that haul material have to do more with less.

Enter the VEGA Inventory System.

How it works
The VEGA Inventory System is a web-based software platform for remote inventory monitoring that pairs with the VEGAPULS 69 to deliver real-time information about inventory, consumption patterns, and free-space in storage silos. These insights help the dispatchers at the ready-mix company and at the material hauling company quickly and accurately assess the inventory at monitored plants and ultimately plan deliveries more efficiently.

Practical Application
Real-time visibility into the on-hand inventory and free-capacity at the ready mix plants provides a more accurate understanding of the actual inventory needs relative to the production schedule. This information helps determine the true delivery window and provides flexibility to route trucks more efficiently. For example, if a silo is nearly empty and can hold five truck loads, five trucks can be sent first thing in the morning instead of looping trucks for the next several hours through the heart of peak traffic. The ready-mix plant and the material hauler both benefit from sharing the information monitored by the VEGA Inventory System.

Conclusion
The greatest advantage for ready-mix plants and haulers of cementitious materials may still be on the horizon. As more plants apply real-time inventory monitoring and remote inventory management with platforms like the VEGA Inventory System, it will be possible to optimize hauling networks based on the flow of traffic and location of trucks, raw materials, plants, and available drive time. The end game is a scenario where trucks are not looped but rather where the truck fleet moves in an orchestrated and efficient fashion from depots to plants, ensuring its customers are sufficiently stocked to meet their production.

VEGA: A complete cement solutions provider

VEGA combines an understanding of user needs and processes with a commitment to the latest technology to provide an array of solutions for the cement industry. From transport to storage to production, you can count on VEGA instruments every step of the way. To see more VEGA’s instruments or talk to product experts at CONEXPO-CON/AGG visit booth B – 92603.