Bench tests prove high efficiency of Roth Hydraulics ‘high-flow bladder accumulators
“Compared to the state of the art we could increase the output of bladder accumulators with the same threaded connection about 40 per cent to approximately 1250 liters per minute. We achieved this through the progressive development of the standard valve” explains Michael Ruth, product manager for bladder accumulators of Roth Hydraulics. For the accumulator specialist the starting point was the market standard valve with a flow rate of 900 liters per minute. Based on a numerical flow simulation with CFX Berlin Software Roth Hydraulics optimized the valve among other things concerning flow behavior, spring characteristics and design of the valve disc. Michael Ruth expounds ”In a further step we developed a new valve with bigger connection by using our obtained knowledge It passed the bench test with great success under the same test conditions that we defined for the test with connection G 2.”
The bench test shows: Roth Hydraulics high-flow bladder accumulators with G 2 connection achieve a discharge volume of 1250 liters per minute (blue graph) and with G 2 ½ connection 1600 liters per minute (pink graph) and exceed the current state of the art significantly.
The flow simulation shows the different output of the standard G 2 and the high-flow G 2 valve. The theoretically determined discharge volumes nearly correspond to the actual measured test data.
Expanded range meets individual requirements
Based on the innovative developments of bladder accumulators Roth Hydraulics offers a new range with three types sized from 10 to 50 liters. Beside the standard bladder accumulator with G 2 connection and a discharge volume of maximum 900 liters per minute there is also a high-flow version with G 2 connection and a discharge volume of maximum 1250 liters per minute as well as a high-flow version with G 2 ½ connection and a discharge volume of maximum 1600 liters per minute. Hartmut Kämmer, sales director of Roth Hydraulics points out “With this our available selection of bladder accumulators enlarges and we can consider different customer requirements in an economic and flexible way. This advancement going further than the state of the art is based on decades of experience and reinforces our competence as an accumulator specialist.”
Velocity distribution of standard G 2 valve at minimally open stroke / Velocity distribution of high-flow G 2 valve at minimally open stroke
Bladder accumulators with versatile applications
The Roth bladder accumulators are suited for use in plastic injection and blow molding machines, in hydraulic presses and for the manufacture of composite components. These are found, for instance, in the automobile industry. A flexible bladder separates the gas and fluid chambers in these accumulators. The bladder is part of a pressure chamber filled with the operating medium. Roth bladder accumulators consist of a seamlessly forged pressure tank, a flexible bladder with a gas connection vulcanized in and the carbon steel or stainless steel connection on the fluid side. In addition to the high-flow bladder accumulators, the Roth Hydraulics range includes many other types featuring different fluid connections.
Roth bladder accumulators are available in volumes ranging from 1 to 57 liters, for operating pressures up to 420 bar and for ambient temperatures from -40 to +80 degrees Celsius. Available bladder materials include NBR (acrylonitrile butadiene rubber), TT NBR (low temperature) and ECO (ethylene-oxide-epichlorhydrin rubber). Roth also offers special materials on request. Offshore applications are available with resistant primers or plastic coatings.
The accumulators are suited for storing energy, for dampening of pressure peaks and pressure pulsation caused by short-stroke, high-frequency oscillations and for volume flow rate compensation, hydraulic shock dampening or cushioning, shock absorption, media separation and emergency actuation. Roth Hydraulics offers comprehensive accessories, adapters, safety and shut off blocks. Services include customer support up to specific acceptance of the accumulators depending on country and application. Roth Hydraulics complies with virtually all globally required certification in this respect.