Quarry and Aggregate

Hycontrol has worked with quarry and aggregate producers since the beginning, and our knowledge of the sector is unrivalled. Common applications in this sector include:

Silo protection for cement and other powdered product
Level measurement throughout sites, including screen-houses, filler silos, gas and fuel oil tanks, and bins
Point-level switches
Bitumen safety systems
Alarm panels
Blocked chute detection
Flow and no-flow monitoring
Remote monitoring

Application: Powdered Product Silo Protection

Ready-mix, concrete and block works have silos on-site that are pneumatically filled from road tankers. Many of the sites have silos fitted with pressure relief valves as their only protection from over-pressure. They can be rendered completely ineffective by constant use and poor maintenance. Pressure relief valves are continuously relieving pressure without engineers investigating or making attempts to eliminate the cause. Road tankers are capable of blowing product into the silos at pressures as high as 2.0 bar. The silo, however, is not a certified pressure vessel and is at risk of rupture at any pressure above one psi. The lack of an effective silo protection system that provides automatic closure of the delivery valve has resulted in silos rupturing and filter systems blowing off the silo roof. This danger is why the MPA recommends the installation of appropriate silo protection equipment.

Hycontrol has pioneered safety equipment in this area and is the only silo protection manufacturer whose systems not only meet but exceed guidance from the MPA. We have worked for years to raise awareness of this issue. Various resources on this topic are available both on this website and www.siloprotection.com. Hycontrol also runs informative day-courses to educate customer staff and managers - please contact us for more information.

Application: Screen-House Level Control

Screen-houses are a standard fixture in the quarry industry. Belt conveyors drop in processed, crushed stone from the quarry site at the top of the screen-house. The rock then passes over a series of different-sized vibrating grilles which initially allows the smallest pieces of dust and stone to fall through into a bin below. As the remaining unsorted rocks descend a ‘staircase’ of slightly angled, vibrating screens, progressively larger pieces of rock (up to a size of 60mm) are allowed to pass through into the appropriate bins. After screening, the sorted stone will be released from discharge points for use in a wide range of potential applications including aggregate, the production of concrete, roadstone and general construction.

Reliable level control is essential not only for inventory purposes when the stone is removed but more importantly for preventing overfilling of the bins. Product overflow will inevitably lead to equipment damage, plant down-time and a costly clean-up, not to mention the potential for Health & Safety issues. The worst-case scenario is if excess product lifts the screens off their vibrating mountings.

In this application, the use of a single sensor will not provide sufficient accuracy, so two sensors per bin are used to give optimum performance. The chosen instrumentation must provide the precision and reliability required to monitor through a dusty atmosphere while having the robustness and durability to cope with damaging environmental conditions. Ultrasonics and radar both meet these different challenges and, when correctly installed, provide reliable level measuring solutions for the screen house. In parallel, regular maintenance is essential for maintaining and prolonging the working life of this equipment. For more information, please read our white paper below.

We are proud to include Aggregate Industries, Marshalls, Tarmac, Hanson Aggregates, Bardon Aggregates, Castle Cement, Ennstone Thistle, Cemex and Lafarge Holcim amongst our customers in this sector. To discuss your requirements further, please contact us.