As building materials are sometimes processed on the company’s own site, in the past the works exit was often dirty. In addition, in dry weather, the vehicles whirled up considerable dust near the office facilities. For this reason, the company contacted Frutiger – the manufacturer of the MobyDick wheel-washing system, to clean, for example, the coarse dirt from the construction machines before they are driven for servicing to the workshop. Coarse dirt washing systems based almost on the same washing technology as the MobyDick wheel-washing system have already been developed by FRUTIGER in recent years for construction machine hire firms, military applications and international mining groups.
In the wheel washing system, quick washing of all axles is required while the vehicles drive through the washing zone. The system must wash off any dirt that would otherwise be carried out onto the public roads. For this reason, it is important that the washing zone measures at least the length of one full revolution of a lorry wheel. In the demucking system, the underbody, the front and sides, and, in the case of tracked vehicles, the running gear have to be washed inside and outside. For this purpose, many additional nozzles, some fixed and some oscillating, are necessary. The time factor is not crucial in a demucking system. Depending on how dirty it is, a machine can be moved forwards and backwards through the system several times. The 5 to 10 minutes needed for a moderately dirty excavator are still much shorter than for a conventional manual wash, which can last several hours.
Besides the time saving and the avoidance of often dangerous and unpleasant manual work, a MobyDick demucking plant offers another big advantage. Thanks to the washing principle: “High volume of water with moderate pressure”, the dirt washed off is not contaminated with oils and grease, and it can be disposed of at low cost. More thorough washing with freshwater and a suitable oil trap can also be performed separately.
Both with the wheel washer and the demucking system, the washing water is completely recirculated. As the focus is on washing off the coarse dirt, water can be recycled simply and at low cost by means of sedimentation. If space is limited, a flocculant can be added to accelerate sedimentation of the solids. The settled mud is discharged at the side on an automatic scraper conveyor into a container.
In addition, during the system planning stage, the idea of washing the mobile screens and crushers on the MobyDick also came up. These machines are generally out and about working at customer sites, but when they are transported to the workshop for inspection, they have so far needed to be washed for several hours beforehand. Thanks to the adaption of the drive-over grate and a flat entrance, these 50-tonne machines can be reliably cleaned, and any coarse dirt removed.