Sensors for aggregate processing applications

Aggregates are used in almost all types of construction from large scale commercial roads, buildings, railways, bridges and tunnels to smaller domestic works.  Types of natural aggregate include sand, gravel and crushed stone. It is not only a key ingredient in concrete but also essential for sub-bases, foundations, drainage and to fill voids, as well as serving a decorative purpose on driveways and footpaths.

Aggregate sizing

Natural aggregates are produced in a quarry or mine, with extraction from the rock via a controlled explosion or by digging from the quarry walls . The rock is then reduced to usable sizes by using mechanical crushing and a series of screens to create particles that are similar in size. Some may be crushed to a powder, while others are refined down to their most common use.

Primary crushing is usually completed with a jaw crusher, while the secondary crusher is often a cone crusher which is used to reduce the size of the aggregate into specific sizes for different purposes. Smaller size rocks are then usually passed through a screener and an impact crusher to size and shape them into a marketable product.

The role of sensors in aggregate processing

To ensure the aggregate is  produced efficiently and effectively, it is essential that the plant and equipment is reliable and operating at optimal capability. The environment can be tough and aggressive with numerous factors potentially having an impact on the machinery, from the hardness and abrasiveness of the materials to inherent moisture and significant levels of dust. All critical components within the machinery need to be able to withstand these conditions and work for long, continuous periods of time. Machinery which fails can cause serious plant downtime with a significant effect on production output.

Among the sensors often found in quarrying and mining machinery are linear position sensors to monitor the size of aggregate being produced, temperature and pressure sensors for the control of hydraulic systems, feeding level sensors to prevent overfilling of machinery, heavy duty angle sensors for drilling accuracy, and robust encoders to provide reliable feedback on positioning, angles or speeds. A large operating temperature range and high protection rating is essential to withstand the requirements of harsh environments.

One example is our P101 stand alone linear position sensor, which is often used in cone crushers to monitor the size of the aggregate output. Manufactured from stainless steel for long life and strong environmental resistance, it can be customised to any length, calibrated to the exact travel required and has sealing up to IP65/IP67 against dust and water.

We can help machine builders develop the right sensor solution for their specific needs and also those looking to replace or retrofit components to existing quarrying machinery or equipment. As part of the Variohm Group we have a wide range of expertise in motion, sensor and measurement components and systems. To discuss further, please contact the team on 44 (0) 1242 820027 or sales@positek.com.