Rail vehicles use sanding systems to ensure safe braking and acceleration. Pneumatic conveyance of coarse-grained quartz sand into the wheel-rail contact area ensures best possible friction ratio even in adverse weather conditions.
The Brake Division rounds off its product portfolio with the newly developed GripMaster®. Managing without moving components in contact with abrasive sand, HANNING & KAHL offers its customers a maintenance-friendly and compact product. Apart from undergoing in-house type testing, eight systems are currently proving themselves in a light rail vehicle in Bielefeld.
The high-grade steel sand boxes have an inlying inspection flap and an outlying filler flap as well as a filling-level sensor. A dosing unit is mounted underneath every sand box, which is generally supplied by a rotary vane compressor. The rotary vane principle ensures rapid pressure build-up and high volume flow. Within the dosing unit, valves distribute the compressed air in such a way that the required sand quantity flows into the conveying hose. A heated nozzle at the end of the hose ensures precise sand dispensation of up to 1,200 g/min. Self-regulating heating cartridges accelerate drying and prevent ice forming on the nozzle.
After each sanding procedure, conveying paths are pneumatically cleaned to prevent deposits and to ensure operation even when humidity is high. If sand is required again during the cleaning phase, the rotary vane compressor is still active and the sand flows directly from the nozzle. The same applies if the sanding system is supplied centrally with compressed air by the vehicle.
Combined with a control device made by HANNING & KAHL, the sand quantity is dynamically adapted to the driving speed. This prevents track clearance signalling systems being influenced by the electrically insulating sand, which is particularly important when speeds are low. Environmental damage by fine dust and contamination of the track beds is kept to a minimum. Demand-oriented use of quartz sand reduces the filling requirement and thus the running costs of transport companies.