Eliminating bottlenecks in the modular wash plant

Able to produce three aggregate products and two sand products from a deposit, modular wash plants such as the McLanahan UltraWASH are a “one stop shop” for your wet processing needs. Material is cleaned, sized and stacked in one quick to install, easy to operate plant.

Modular wash plants use a combination of sizing screens, pumps, hydrocyclones, dewatering screens and conveyors to clean aggregate and separate it into up to five product sizes. As McLanahan knows not all deposits are the same, the UltraWASH modular wash plant – which was launched earlier this year at bauma 2019 – is designed to accommodate the gradations of many different deposit types.

{{quote-A:R-W:175-Q:“Wouldn’t it be great if you could add more of the fine sand to the coarse side, pre-blending the material and effectively balancing your downstream equipment?”}}For example, say you have an excess of fine sand in your deposit, so much so that it is causing a bottleneck in the hydrocyclones. Bottlenecks are never a good thing – they slow down production and reduce the amount of the product going through the plant per hour.

The hydrocyclone that processes the finer sand is working at capacity, with finer sand lined up behind it in the pump and sump awaiting processing. The hydrocyclone that processes the coarser sand, however, isn’t being used to its full capacity, as it has less sand to process. Wouldn’t it be great if you could add more of the fine sand to the coarse side, pre-blending the material and effectively balancing your downstream equipment?

FINES FORWARD SLIDE

McLanahan Corporation thought so, which is why it has designed the UltraWASH with a patent-pending fines forward slide. The fines forward slide divides the bottom screen level of the sizing screen to separate the fine sand fraction from the coarse sand fraction so that the coarse sand falls into one side of the sump and the fine sand falls into the other side of the sump.

The fines forward slide divides the bottom deck of the screen across its width. The fine fraction falls onto the first 40 per cent of the screen, while the coarse sand fraction falls onto the remaining portion of the screen.

The fines forward slide can be moved to cut into the fine sand side, meaning that it becomes processed with the coarse sand. This reduces the load on the fines processing stream, removing the bottleneck and potentially increasing the feed rate to the plant. The final blending of a primary sand product by mixing fines with the coarse sand stream is effected as the two streams leave the dewatering screen.

MAXIMUM YIELD

To further meet the needs of a variety of deposit characteristics, scrubbing, crushing and screening modules can be added to a modular wash plant to remove contaminants, blend or classify material, break up heavily agglomerated deposits and separate the oversize particles. Scrubbing, crushing and screening modules can be fitted easily into existing plants to provide more advanced washing, further reduction of material and further separation of product sizes.

{{quote-A:R-W:175-Q:“The fines forward slide can be moved to cut into the fine sand side, meaning that it becomes processed with the coarse sand”}}Another way to maximise product yield is by proactively maintaining the modular wash plant. A minimum recommended maintenance schedule should be included in your installation, operation and maintenance manual from your OEM.

A typical schedule includes routine inspections once every shift (or every eight hours of operation), once a week and then once every three months, every six months and every year. These inspections include checking components for wear or damage, checking or changing oil, and checking electrical and water lines for wear or damage, along with other recommended inspections outlined in a modular wash plant manual.

Establishing a routine maintenance schedule and sticking to it are very important. These inspections can reveal repairs that need to be made before they lead to a breakdown. Keep replacement parts in stock and repair damaged or worn components as soon as possible to avoid downtime.

You can also maximise product yield by providing a constant, consistent feed. Here are some common practices to avoid when operating your plant:

Overfeeding.
Stopping and starting the feed.
Varying the characteristics of the feed material.

These three practices can cause high wear on the plant and lead to material stoppages and unscheduled downtime. Continuously running material through a modular wash plant for the duration of the shift will reduce wear on the plant’s components and produce higher quality products at a greater yield.

Proactive maintenance can ensure your machine is at optimum operating efficiency, while the innovative fines forward slide helps maximise production.

The McLanahan UltraWASH modular plant is now available through the Lincom Group, McLanahan’s Australian distributor.