Manufacturer hydraulically breaks the mould

A manufacturer of aerated wastewater treatment systems called BioSeptic is using compact and powerful high-pressure (700 bar) hydraulics to help deliver a more efficient, safe and precise way to produce its concrete tanks.

Enerpac distributor South West Hydraulics assisted the company to devise a precision hydraulic system to break open the tank-forming moulds and to position the processing tanks for craneage at the factory.

The tanks produced there, using the interconnected Enerpac hydraulic system, are generally 2.1 m high, 2-2.5 m in diameter with 50 mm walls. They are made from 40 MPa cement, which is vibrated to help ensure a solid casting, and threaded with a fibre steel to enhance durability and strength-to-weight. Each tank, ultimately weighing 3.5 to 4.5 t, is formed on a base with an inside mould and an outside mould to give precise shape and performance characteristics.

Rather than breaking the moulds using a disconnected array of bottle jacks - each with a couple of pumps to power extension and retraction - BioSeptic uses four 25 t RC256 Enerpac cylinders all interconnected through an Enerpac valving manifold. This integrated solution runs from a single air/hydraulic Enerpac PARG 1102N Turbo Pump, which recycles its own exhaust gases to increase power and lower air consumption and operating costs. The pumps - part of a family with 0.08-0.16 oil flow at rated pressures - can operate at air pressures down to 1.7 to 8.6 bar, a useful feature that enables them to start at very low pressures.

The BioSeptic hydraulic installation - which is capable of being operated by remote pendant for additional safety - feeds its four single-acting cylinders via manually operated V valves that can be closed to safely hold the load in any position. The cylinders are precisely located within custom-fabricated steel brackets for additional stability, safety and precision.

"The Turbo Pump and 25-tonne cylinders provide the power firstly to break the tank's bond with the inner mould, then to lift it about 100 mm so an overhead crane can take over the job of hoisting it away for finishing, storage and delivery," says factory manager, Ray Halls.

"Quite high tonnages are required to break the bond with the inner mould and to lift it - upwards of 50 t - and the job needs to be done in a timely and very safe manner to keep production flowing smoothly." The tank's bond with its outer mould is broken by Enerpac cylinders operating horizontally. These are powered by a simple Enerpac hand pump, the two-speed operation of which reduces handle strokes by as much as 78% compared with single-speed types. The cylinders for this operation are also securely located within custom-fabricated steel brackets, giving high safety and precision.

"The old way to break the concrete's bond with the mould is to spread four bottle jacks around the perimeter and run around pumping up each one a little bit at a time. This is pretty crude, because the equipment used is basically a truck jack and the methodology is guesswork. Where you are producing hundreds of quality tanks a year, like we are, that method leaves far too much to chance," says former mine engineer Halls.

"All our systems were designed with Enerpac's and Southwest Hydraulic's help. We've never had any troubles or lost production time due to equipment failure. They've always supplied us with what we needed very quick."