Construction machinery and equipment

Description

Preparation plant for concrete. Concrete mixing plant consisting of 10 silos each with 1,5 m3 raw materials (aggregates, sand, cement) with an automated and computer-controlled dosing system. The base area of the mixing plant is 19,5 m long and 6 m wide (incl. steel construction). The raw materials are supplied in big bags, lifted with a chain hoist and emptied into the silos. DTU Civil Engineering intends to acquire a concrete mixing plant consisting of 10 silos each with 1,5 m3 raw materials (aggregates, sand, cement) with an automated and computer-controlled dosing system. The base area of the mixing plant is 19,5 m long and 6 m wide (incl. steel construction). The raw materials are supplied in big bags, lifted with a chain hoist and emptied into the silos. A complete emptying of the material silos is possible at any time due to the plant arrangement. The raw materials are dosed individually, encapsulated by means of dosing devices from the silos into a movable scale according to the recipe. There must be a separate position at the plant to feed manually weighed products in to the mobile scale. The mobile scale collects and transports the weighed-in raw materials to the new 150 l mixer 1, mixer 2 (is an existing mixer 250 l) or to a 3rd discharge point. Due to the available height in the customer rooms, the mobile scale is lifted to fill the mixers gravimetrically. The complete weighing, dosing and mixing process is connected to a dedusting system and at all charging and discharging points the scale docks with a sealing system to the feeding or discharging points. The mixers are installed in a separate room next to the silo system. The water and the 2 liquid additives were dosed into a transparent weighing hopper according to the required mixture proportions. The liquid scales are an integral part of the system (incl. filling pumps). The mixing plant contains a concrete mixer with a volume of 150 litres. The material is transported through the rotating mixing pan to the mixing tool, such that less wear will be expected. The mixing tool itself can be operated with a variable circumferential speed of between 1–30 m/s. By decoupling of the material transport from the mixing tool (inside the mixer), a very flexible mixing effect is possible — independent of the consistency of the material. Exchangeable mixing tools increase the variety in order to prepare different types of concrete such as SCC, UHPC, FRC. The mixing technology ensures a homogeneous concrete mix and meets the highest demands. The mixing direction must be variable and clockwise or counterclockwise mixing must be possible. Mixing under a variable mixer inclination (between 0 and 30 degrees) in combination with a fixed material deflector produces natural vertical gravity circulation in the mixing pan. The mixer has an integrated high-pressure cleaning system. To empty the mixer, the mixer pan tilts. The system is operated and controlled via touch panel, tablet and PLC computer software. It must be possible to access the plant control system from an external computer. The mixing process is controlled and documented with regard to mixing energy input, individual mixing times, humidity and temperature of the mixed material. These data are recorded and archive accordingly and assigned to the mixture (batch).