Our History – Filter Invention and Innovation

How Inventing a Self Cleaning Filter Started a Company

Rotorflush Filters Ltd has over 20 years’ experience of self-cleaning filter invention and innovation.

JimThumbJim Hosford is the company founder, Managing Director and inventor of the Patented Rotorflush self-cleaning filter. We have been manufacturing self-cleaning filters since the invention of the first Rotorflush. We are continually adding to our products and refining our designs through filter invention and innovation.

In the UK many water companies specify Rotorflush filter pumps with self-cleaning intakes for water treatment applications.

Several forward thinking manufacturers of water monitoring equipment recommend Rotorflush to protect their products. Our innovative filters are now sold all over the world across many industry sectors.



Because our filters offer a simple answer to an old problem. How to pump dirty water without blocking your pump or its filter?

Our filters separate solids from dirty water. Because they are self-cleaning filters they protect your pump and don’t block.

Jim Hosford is the company founder, Managing Director and the inventor of the Patented Rotorflush self-cleaning filter.

It all really took off with the pond filters,exploded view of pond filter showing filter invention and innovation                     but before we get on to that…

cut out cow dairy farmer filter invention and innovation

The Idea

Rotorflush Filters Ltd was started by Jim Hosford in 1995, when he was a dairy farmer. He started the company to market a very simple self-cleaning filtration system.

He had invented the filter because he was fed up pumps and strainers blocking when he pumped waste water from his dairy farm.   The filter supplied with the pump he was using on his farm kept blocking every hour with straw and cow manure. He thought there must be a solution to this problem.


tractor pump filter invention
Prototype self-cleaning filter in a slurry pit at Broompound Dairy

Filter Invention and Innovation.

Jim came up with a simple design to keep his pump working and to stop the filter blocking.  He found that by driving an internal cleaning rotor in the filter with a proportion of the output of the pump he could continuously backwash the filter screen whenever his pump was working.

In 1994 he developed a prototype filter for dirty water to be used at Broompound Dairy, close to his farm in Dorset.  This filter worked even better than he had hoped. The filter worked almost continuously for 2 years without blocking.

Eventually the tank from which it was pumping needing cleaning out, owing to the build-up of solids backwashed from the filter.


 Farmers Weekly Awards - prize for filter invention and innovationCompetition – 1

In 1995 the original prototype was entered into the Farmers Weekly Invention competition, (a farming magazine in the UK), it won first prize in its class. Other farmers were soon asking him if he could make one for them.

So, with the help of a local foundry, in 1996, the first production models were produced for farmers. The production version was entered for the Douglas Bomford Award for innovation where it was awarded second place.


Farmers Weekly reported that “Invention Competition winner goes into production”. It was time to take a risk – Farming or Filtration?  Filtration of course, and the Company name was coined – Rotorflush Filters.


Advertising and Marketing

1997 was the year of a big marketing push for the self-cleaning filter. Jim exhibited at trade and agricultural shows, where there was great interest, particularly in his small demonstration filter.  Display stand at Barbican promoting Rotorflush self-cleaning suction intake filters In promoting the self-cleaning suction intake filter at shows around the country, Jim was constantly being asked if he could do a small one for garden pond pumps.  Garden pond pumps and their filters frequently get blocked with algae and weed.
A garden pond - possibly in need of a self-cleaning pond filter Worse still, most ponds are maintained to attract wildlife but many pond pumps can trap and kill tadpoles and young newts.  In 1999 Jim produced a small plastic injected self cleaning filter for the garden pond market.

The Rotorflush pond pump filter with its fine mesh and gentle backwash kept pumps clear and wildlife safe.


Pond filter boxCompetition – 2

With the help of sales agents and licensing agreements pond filter sales rocketed. The pond pump filters were phenomenally successful – over 60,000 units sold in four years.  In 2000 the pond filter was awarded ‘Millennium Product’ status and was exhibited at the Millennium Dome in London as an example of filter invention and innovation.

The success of the pond filters enabled Rotorflush filters to commercialise the prototype agricultural filters which Jim had originally developed.  These rapidly became useful beyond the farming market.

Other areas where the filters were first used are lorry washes, vegetable washers, extraction of river water for irrigation, recycling of sewage water for wash-down to name a few.

The demand for effective low maintenance hassle free pumping and filtration at source has spurred Rotorflush Filters to diversify and refine designs for self-cleaning suction intake filters.



Industrial self-cleaning filter products

Building on the success of Rotorflush self-cleaning suction intake strainers and filters for use with dry mounted pumps Jim considered the use of his invention with submersible pumps. Combining pumping and filtering directly from contaminated source water would be a boon to irrigators, open loop heat pump installers and indeed farmers pumping out settlement tanks and lagoons.

The next significant filter invention and innovation was to build in a self cleaning suction intake to submersible pumps.  This allows multi stage centrifugal pumps to be used in dirty water without the pump blocking while the filter mesh stays clear. Over time the range and capacity of these filter pumps has grown.

What innovation and invention can do for self cleaning filters

Analyser filter sysrtem - filter invention and innovationFilter Invention and Innovation – Self-cleaning Filters for Analysers


Rotorflush Filters Ltd supplies self-cleaning filtration products specifically developed for water monitoring instrumentation.

The Rotorflush RF100AN is an automatic self-cleaning filter system specifically to filter water providing output to your analysers without blocking the cells. Output of the system is up to 20 litres/minute.


big blueFilter Invention and Innovation – Horses for Courses

Keeping Race Horses Cool!
Horse relaxing in clean water thanks to big blue filter system

Several years ago Rotorflush developed an inline filter system for a company making exercisers for race horses.

After a race, horses are exercised in cool salt water to wash any wounds and relax their legs. The horses are walked through circulating salt water, which of course needs filtering.

Unable to find a filter system that would remove manure, the company worked with Rotorflush to develop an inline filter system to do the job. This product is now made by the company under licence.


Filter Invention and Innovation – Oil and Gas

Our products can be scaled up to suit any application – the hall mark of a great filter invention is its ability to be applied to the task in hand. So when a major oil company needed a lot of river water filtered to pump down oil wells – a Rotorflush custom built self-cleaning filter was the only way to go.

Filter invention and innovation - Large Rotorflush filters off to sunnier climes!
Large Rotorflush filters off to sunnier climes!

Filter Invention and Innovation – Inline Self-cleaning Filters for Industrial Process WaterSOB001 Complete 1

More recently Rotorflush have developed a self-cleaning filter to remove lint from hot industrial laundry water. This superb inline filter advances our self cleaning technology – operating at pressures of up to 8 bar and filtering down to 30 microns.

All stainless steel pressure vessel and fully automated pressure sensitive controls make this our most advanced filter yet. A clever solids waste handling system ensures very high water efficiency, and an automated purge system guarantees low maintenance.

And not just for laundries – this system can tackle most industrial process water contaminated with suspended solids where there is a need for inline filtration.


Filter Invention and Innovation – What Next?

We never sleep – we are busy workingh on the next filter invention, pursuing the holy grails of higher capacities from smaller filters, and new inventions to enable pumps and filters to work effectively in even worse water conditions.

Get in touch to find out more!