Search for the ultimate solution

Tighter environmental legislation and a desire to reduce their discharge bills has led many companies to opt for bespoke pumping and mixing systems instead of off-the-shelf products

Finance may act as the main driver for the increasing number of companies looking to improve the consistency of their wastewater discharge, but if they choose off-the shelf pumps, are they merely laying their hands on ‘a’ solution, instead of ‘the’ solution?

Nobody can doubt the volume of sales in standard pumps speaks for itself. However, tighter environmental legislation and the undoubted incentive to reduce discharge bills to water companies is seeing an upsurge of more tailored solutions to meet these needs.

Landia, with years of wastewater application experience, believes custom-built in-line mixing systems are the way forward for companies seeking continual improvement of their environmental standards.

Landia’s sales director Hugh Vaughan said: “Everyone wants to reduce costs by paying less discharge money to their water company, but we see a definite trend from forward-thinking environmental managers who understand every bit of help that can be given to the overall process will reap rewards – and this is not readily achieved with bog-standard pumps.

“Investment in a good quality, bespoke pumping system, designed for their specific needs, is what will really add value.” Vaughan firmly believes gaining an understanding of a client’s needs is essential and that, while at first the best possible solution seldom looks like the cheapest, more and more industrial firms are basing their decisions on ongoing enhancement as they endeavour to reduce suspended solids.

Landia’s most recent example of a custom-built installation was the refurbishment of a company’s effluent plant, which included the installation of three Landia’s Air Jets.

This comprised one in each of two aeration tanks mounted externally, while one submersible Air Jet, combined with a Landia 150rpm submersible mixer mounted inside a balance tank were brought in to improve aeration and also give the added benefit of keeping solids in suspension. Designed with a special chopping system for use in harsh environments, Landia’s Air Jet is low-maintenance, even in this demanding industry application where large dry matter particles are common.

As well as reducing unpleasant odours, Air Jet can also provide supplementary aeration during peak periods of effluent oxygen demand. In addressing this particular wastewater application, Landia also included a self-aspirating pump so the tanks can benefit from better mixing patterns. “Almost every wastewater liquid is different”, added Vaughan. “Those companies that want to improve their systems should take advice on the positions chosen for both a tanks’ inlet and outlet, which can be crucial. The angles chosen for sludge aeration equipment are also vital, because if you do not get it right, the whole process is likely to fail.”

Landia’s experience in food and agricultural pumping systems has, for example, seen it design and install pumping and mixing systems for wastewater from vegetables, but instead of an off-the-shelf answer, each application is treated individually. A recent example saw the company install its chopper pumps at two locations, one where potato processing was being carried out, the other for onions. “The configuration of the inlets had to be very different from one another because of the dissimilar characteristics”, said Vaughan.

“Both products have starch but there is a significant amount of grit to handle with the processing of wastewater from potatoes, whereas onions produce a large amount of floating matter. Either way, for any effluent that can contain large solids, you also need pumps strong enough to smash and mash their way through – without breaking down.” In a particularly common example facing the food industry, a potato processing company called for Landia’s help earlier this year to aerate its storage lagoon, which was producing very bad odours. In this application, a dry-installed pump was introduced to aspirate the wastewater. Motors from 1.1-18.5kw can be utilised to provide a simple, yet highly effective system – available with an extremely resistant sealing system and in materials durable enough to combat aggressive, corrosive or abrasive liquids.

Choice of materials is therefore also high on Vaughan’s and Landia’s agenda. Cast iron is not ruled out but, on the whole, the most common two-word phrase will be stainless steel. “For inlets and outlets, we do not feel it is right to compromise”, continued Vaughan. “It has to be stainless steel, not galvanised. Not only that but stainless steel provides many more options during installation, especially if things have not quite gone to plan. And if you really want a pump that will not block and cause downtime, even when dealing with an effluent or sludge that has a high-fibre content, stainless steel impellers and cutting systems are the best investment.”

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