A tale of two technologies

As the world continues to grow, there are at least two nearly guaranteed outcomes: the demand for cement will increase, and so will the need for cement companies to effectively and reliably store and reclaim their dry bulk cement. However, the process of keeping that fluidisable material dry and flowing out of its storage structure can be complicated and expensive.

There are several different kinds of systems that can be used for reclaiming dry cement. For concrete domes or large silo storage structures, those systems typically consist of aerated floors and a mechanical reclaimer, or some combination of the two.

In a common configuration, the entire floor of the dome or silo is fitted with aeration equipment. When activated, depressurised air is used, which fluidises the dry cement through large grates over the floor, enabling it to be removed from the dome.

Hybrid solutions, which combine aeration and mechanical reclaim, are a customisable and cost-effective option, and offer the flexibility some companies will need as they scale and adjust their businesses to meet today’s demands. Laidig Systems has successfully engineered, built, and commissioned multiple systems that utilise this hybrid reclaim method: the Fluidized Screw Reclaim system.

How it works

Initially developed for a large-scale cement manufacturer, the Fluidized Screw Reclaim system integrates Laidig’s mechanical screw reclaiming machinery with the proven effectiveness of aerated floors. In doing so, it was possible to integrate other benefits that traditional cement reclaim systems cannot commonly provide: full reclaim automation with push-button operation to reduce labour costs, a fully reversible sweep auger for maximum process flexibility, and true near-total cleanout.

The system’s success lies in the dual nature of the technologies it implements because they work to complement each other.

The process in which it works starts by using air gravity conveyors, which are arranged around an aerated centre hub in a radial spoke pattern that looks like a bicycle wheel. They fluidise the floor and clean out a portion of the material inside the dome. This may sound like a traditional aerated floor system, but it saves tremendous amounts of energy by employing a strategic pattern in which the air conveyors are activated: they activate individually and sequentially around the floor – not all at once. The pattern reduces the amount of power it takes to operate them, while also reducing uneven load pressures on the structure and its foundation.

After the air reclaims approximately 80% of the stored material, there are pie-shaped piles left around the dome floor. That is where Laidig’s rugged mechanical reclaiming technology comes into play. When the mechanical screw is engaged, it works by rotating about its own axis, pulling material down toward the aerated centre hub. At the same time, the screw slowly advances around the dome floor, further breaking down the material and any hard-packed masses.

Through the use of Laidig Smart Controls, the air conveyors automatically activate to work right alongside the screw reclaimer. The two work in tandem until cleanout is completed.

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Read the article online at: https://www.worldcement.com/special-reports/07082023/a-tale-of-two-technologies/