We all know that grit entering water treatment works causes massive issues with process efficiency and that the degree of grit entering the works is vastly underestimated.

The grit removal systems previously offered are seriously lacking in performance and are only removing approximately 30% of the grit entering the works, whilst 70% continually passes through the treatment works damaging mechanical equipment on its way, the rough surface of the grit particles allows other organic matter to bind resulting in clumps causing blockages and accumulation in digestors and primary tanks reducing the output capacity of the works dramatically. The cost associated with grit is in the region of £100,000 per annum. These costs have become accepted and form part of business as usual for most companies and maintenance budgets are burdened with excessive and avoidable costs.

Conventional mechanical rakes are known to be highly inefficient and on average in optimum conditions only remove 20-30%. They are prone to frequent breakdowns and blockages which have to be removed by operator interference which introduces H&S risks.

Existing mechanical rakes consume on average 30,000 kW h per annum which generates around 4,000kg of CO2. When we are all looking at carbon reduction this cannot surely be the best option going forwards and a more sustainable solution needs to be found.

EMS The Smart Solution

The HYDRAKE is an innovative hydraulic alternative to the conventional mechanical rake. The intelligent system detects the position of the rake and allows the operator to take full control.

In optimum conditions it can remove 95% of all grit particles with a diameter greater than 0.2 mm with a specific gravity of 1.2ms-1 outperforming all mechanical variants. This will lead to improved sludge quality, tank capacity and the reduction of wear to downstream plant.

The design features:

1 Adjustable speed and grit bed depth to suit individual site needs

2 Forward and reverse remote operation to allow removal of blockages without interference

3 Longer rake stroke maximising efficiency

4 Horizontally installed eliminating the need for steel support structures

5 Low-cost servicing

6 Rake angle and length can be adjusted to fit into existing civils works

7 Two-part rake assembly allows for uncomplicated installation

8 Only eight greasing points which can be accessed without major interference

The adjustable rake length and angle means the HYDRAKE can be installed in place of mechanical rakes without the need for costly civils works. It is installed horizontally and does not require steel support framework. The installation and commissioning can be completed in 5 days.

The variable speed control allows adjustment to match influent flow and a significantly lower operational RPM make the EMS HYDRAKE an energy efficient solution that will improve the grit capture and in turn improve process efficiency, reduce downstream maintenance costs and reduce the carbon footprint of the site.

HYDRAKE comparative performance data:

EMS HYDRAKE Comparison with mechanical rake
Grit removed per annum (tonnes) 264 97% Increase
Energy Consumption (kW h) 7,500 75% Reduction
CO2 Emissions (kg) 1780 55% Reduction
Annual Maintenance cost (£) 498 90% Reduction



EMS HYDRAKE is the best solution for the removal of grit in the waste water treatment industry. It provides a cost effective and sustainable option which is proven to outperforms mechanical rakes. The EMS HYDRAKE is currently operational in several UK treatment works and is demonstrating its benefits.

Customer testimonials

“The system has performed beyond expectation by removing significantly more grit from the system compared to the previous conventional equipment. In the six months running there have been no breakdown, and the greatly increased grit removal has reduced wear on downstream equipment.”

“Average emptying requirement frequency of approximately every two weeks. The Site Operative previously reported that when the old rake was in operation the skip was emptied approximately every month”