Meeting challenges in the mix

Manufacturers of mixing, blending and dosing equipment are having to address an ever more challenging and widening range of criteria to meet the requirements of owners and operators in the process industries.

Perhaps the most significant current trend is the growing importance of health, safety and environmental factors in the specification of equipment and systems, and in some instances, it is actually the suppliers that are ‘raising the bar’.

Mixing and pumping equipment supplier Landia, for example, has taken clear steps to demonstrate that it has the tools, systems and people to supply end users in its various UK and overseas markets.

UVDB is particularly hot on areas of high operational risk…

To this end, the company has adopted Verify - a system run by independent auditor Achilles, which identifies, qualifies, evaluates and monitors suppliers seeking to do business with major corporations worldwide.

In an audit by Achilles, Landia UK achieved a 100% pass rate for quality in its latest UVDB Verify approval audit. The company also achieved a rating of 98% for health & safety and 93% for environment in an on-site assessment.

According to a Landia spokesman, the company believes that there are plenty of players, especially in the new biogas market, that cannot offer such a rating, so that there are gaps in their ability to supply.

“Whilst there are of course health & safety issues everywhere, UVDB is particularly hot on areas of high operational risk,” he commented.

Elsewhere, recent contract wins show how UK-based companies do deliver such top-level equipment and support for major projects.

Chemineer, for instance, has been selected to supply 66 rubber-coated mixers for a huge seawater desalination plant in Saudi Arabia.

The mixers will provide pre-flocculation and flocculation duties. Each mixer has been coated in chloroprene rubber for operation with seawater, and is also designed with special sunshades to protect against extremely high local ambient temperatures.

Back in the water sector, new dosing technology is helping to resolve a longstanding problem at a Canadian utility. Located in southern Ontario on the western shore of Lake Simcoe, Barrie is a modestly sized city (135,000 residents).

Here, the water operations branch of the Corporation of the City of Barrie has a remit to ensure the supply of safe drinking water. This requires protecting both public health and the environment through the development, implementation and maintenance of a quality management system.

A long-standing issue had remained ‘unchecked’ on the list of challenges faced by Ron Baumgart, lead hand for ground water supply within the water operations branch.

“Because we have a high concentration of iron and manganese in the Barrie region we use sodium silicate (Na2SiO3) as a sequestering agent in the potable water we supply to customers,” he explained.

At four-to-six parts sodium silicate typical dosage, diaphragm pumps were the units of choice until recently. However, maintenance costs meant a suitable alternative has long been on the wish-list.

“Sodium silicate tends to give a hard coating to the ball valves found within diaphragm pumps,” said Baumgart. “This leads to clogging, meaning the pumps require disassembly and repair.

Another problem is that the silicate will dry up when the diaphragm pumps stop, an effect that damages the actual diaphragm when pumping operations recommence.

To address this, the utility trialled a pre-production Qdos metering pump from Watson-Marlow at a potable water station in June 2011.

“We got the dosage set up and didn’t touch it - it just ran,” said Baumgart. “Last April we got a production version Qdos 30 with patented ReNu pump-head technology and it’s still in place to this day.

Again, we haven’t needed to impart any maintenance whatsoever. “We are looking to replace diaphragm pumps when they reach end-of-life or as we upgrade our SCADA control systems; and these pumps are now added to our preferred suppliers list,” concluded Baumgart.