PS1000 effluent pressure separator

February 2006
The PS1000 pressure separator takes out the solids from farm dairy shed effluent before the liquid continues into the treatment ponds. The wash down water and solids are collected in the sump or collection tank adjacent to the farm dairy, then agitated before being pumped up to the PS1000. Inside the augur propels the slurry into the screen while separating out the liquid. The dry matter comes through the screen and then falls into a hopper, from which it is then mixed with other dry fertilisers or spread on its own over pastures. Engineer Murray Smith, from Industrial Stainless and Design, says the PS1000 would operate perhaps once a day and treat 30,000 litres during 45 to 60 minutes. It operates with a 3kW motor, so is not using a great deal of electricity.

The PS1000 is considerably cheaper and requires less maintenance than some German pressure separators available in New Zealand. The German machines have fine tolerances between augur blades and screens, meaning more adjustment and refurbishing. The PS1000 has brushes along the augur blades, which is a unique system to make the machine a lot lighter to do the same work and operate longer without needing work. When it does lose efficiency, Industrial Stainless and Design will send out a swap augur while the old one is being refurbished. The PS1000 has no special seals and operates with a standard gearbox.

The cost of under $20,000 makes pressure separation in reach of all dairy farmers.

Dry manures and waste waters are comparatively easy to handle; it is the slurry mixes which present more problems. So the solution, separate out the slurries. The resulting products make good manures, both dry and liquid. Many nutrients are recycled back to the pastures. The effluent ponds wont clog up and the anaerobic treatment process goes on more effectively because there is no surface crust forming. Wind and wave action assists the anaerobic process.

Farmers perspective

Gordon Nelson milks 315 cows at Wellsford, spring calving only. Nearly two years ago he installed a feeding platform and the effluent separator at the same time. It operated intermittently until earlier this year when the feed platform came into regular use. Now the PS1000 is run automatically once a day, controlled by float switch. It takes up the effluent from the sump, which is a result of washdowns from the farm dairy, the feeding pad and the wintering barns. The resulting liquid has about 90% of the nutrients, according to Gordon, and is pumped out to a travelling irrigator on the flatter parts of the farm. The solids extracted are comparatively sweet smelling and they are collected into a fertiliser spreader with a six tonne capacity and every few days driven out to the hillier areas of the property and spread. Over time the savings in chemical fertilisers will repay the cost of the separator and fertiliser spreader. The liquids had to be collected and sprayed anyway, before the separator was installed. Because the collection area was being greatly increased by the construction of the feeding platform, Gordon had to increase the size of his effluent spraying and buy a new travelling irrigator. Separating out the solids improves the performance of the irrigator, which is less likely to break down or clog up.

Manufactured by Industrial Stainless and Design, Whangarei