BHS-Sonthofen’s mixers from Bavaria on the roof of the world
First publishedon www.AggBusiness.com
BHS-Sonthofen batch mixers are producing concrete for a hydro dam being constructed near the Tibetan city of Zangmu
Six twin-shaft batch mixers delivered by BHS-Sonthofen are producing concrete needed to build the main embankment of the Dagu hydro dam being constructed near the Tibetan city of Zangmu.
The construction site is located 3,700m above sea level, making this the most elevated site ever for employing mixers from BHS, and the company specially modified the DKX 6.0-type mixers to meet the challenges they are facing at this extreme altitude.
Soon after the first two mixers started producing the first batches of concrete, Sinohydro No. 9 Engineering Company commissioned four more units.
The mixers will produce approximately 3 million tonnes of roller compacted concrete (RCC) over the course of the dam’s construction, which is scheduled for completion in 2019.
The complete facility, which comprises six mixers, is dimensioned to produce 160,000m³ of hardened concrete/month.
The mixers are equipped with a coarse-grain mixing unit for processing grain sizes up to 160mm, as is typical in hydro dam construction.
About 6m³ of hardened concrete is discharged per batch at a rate of up to 48 cycles/hour, resulting in a total yield of up to 288m³ of hardened concrete/hour.
The cycle times are short due to the intensive mixing of the concrete and the extra-large rotary valves at the underside of the mixing trough, which significantly speed up the discharge process.
The construction site is 3,700m above sea level
Given the vast amount of concrete that needs to be processed, BHS-Sonthofen reinforced the mixing troughs with a tougher version of its 28mm Optilong wear tiles, whose service life is said to be nearly twice as long as the diamond-shaped tiles commonly used in construction projects. The variable hardness of the individual tile rows ensures uniform abrasion across all wear zones.
The remoteness of the construction site posed yet another challenge. The construction site in Tibet is nearly 4,000km from Tianjin near Beijing, which is where BHS-Sonthofen’s Chinese subsidiary is situated. It took 20 days to transport the mixers across this distance.
Once completed, the Dagu dam will be 126m tall with a dam crest measuring 385m.
The power plant will generate 640MW of hydro energy, and the dam is part of a major project undertaken by the Chinese government to provide the eastern parts of the Tibetan Autonomous Region with electricity, all the way to remote villages.
Multiple hydro dams are damming up the Yarlung Tsangpo, the world’s highest river, which crosses Tibet from west to east and continues through India, where it is called Brahmaputra.