Automatic sand distribution
Transporting core sand with a monorail system
Loading of travelling container with core sand
Although sand cores are “lost” soon after they are made, they are essential for the manufacture of faucets and valves. Without them, it would not be possible to make castings with internal cavities and, therefore, there would be way for liquid to flow through faucets, in which they serve as placeholders. The machines that form sand cores are supplied by a distribution installation, which is equipped with components from the KBK crane construction kit by Demag Cranes & Components.
Oras Oy, a company that utilises this type of sand distribution system, is the largest Scandinavian producer of faucets. Based in Rauma, Finland, the company specialises in touchless mixing faucets. In December 2008, it ordered core sand processing and distribution systems for its plants in Finland and Poland from the engineering company KLANN Anlagentechnik GmbH, which is based in Hagen, Germany.
Compact monorail system as an essential part of the solution
KLANN, which is a well known core shop equipment manufacturer in Germany, delivered a mixing system and distribution facility for the Scandinavian Oras plant that supplies the core shooting machines with sand from the foundry ground level.
KLANN employs a Demag monorail made of the KBK II-R profile section with an internal power supply and an electric-travel chain hoist. In Finland, the KBK system operates with lifting speeds of 8 and 2 m/min and travel speeds of 4 to 40 m/min.
The travelling hoist that runs on a monorail supplies 12 core shooters on its approximately 40 m-long travel path. The chain hoist lifts the container, which is filled with the required sand mixture by the mixer at ground level, to a height of some 3.6 m. When it has travelled to the feed position, the container is emptied above the relevant shooter by means of an electrically powered flap. Due to the space available in the factory in Finland, KLANN selected a U-shape layout instead of a straight line. The control data are transferred by WLAN (Wireless Local Area Network).
compact design of the travelling hoist system
Gentle transport in a minimum of space
The travelling hoist units which are specially developed for transporting bulk materials in a minimum of space, and have a container volume of 50 l in the installation designed by KLANN, meet important requirements for high quality cores. The gentle motions ensure that the core sand is not separated, that the grains are not ground, that dust is not created and that the sand is not compacted. In addition, they provide minimum contact with the air, so the binding agent does not dry out or react, and that the finished sand mixture is supplied to the core shooter in good time. Since the mixture is transported in batches, uniform dwell times are ensured. This arrangement utilises the benefits of overhead handling by means of KBK lines, as worm, belt and drag chain conveyors as well as vibration chutes would be unsuitable for this application because they would have a negative effect on the core sand mixture.
The use of standard components from the KBK crane construction kit by Demag Cranes & Components also makes it possible to achieve simple and cost-effective design and maintenance of the installations, and a reliable supply of spare parts is also guaranteed, if required.
Reduced operator burden and improved productivity
Oras had already been working with a KBK II system and a chain hoist supplied by Demag Cranes & Components before investing in the new solution. The reason for the restructuring was the plan to provide an automatic supply solution for the core feed machines in order to reduce the burden on the operators and to improve productivity. In the past, every worker had to fetch the bucket of core sand from the mixer using a trolley and then attach it to the load handling attachment of the chain hoist, which required a lot of time and energy. The entire procedure took 5 to 10 minutes. During this time, the machine was unable to produce any cores. The situation was exacerbated by the fact that the operator had to repeat the procedure at intervals of 30 to 60 minutes.
Today, he selects the required ingredients, including the quantity of binding agent, at the control panel at the beginning of the shift. It is then only necessary to press a button at the core feed machine so that the travelling hoist unit automatically brings the selected mix of core sand approximately 5 minutes later.
To be able to offer its distribution system at an even more competitive price, KLANN defined further standards for the travelling hoists. An example of this is the use of the KBK-II-R profile section an internal conductor line. This profile section offers significant advantages compared to the previous trailing cable arrangement, which could not be implemented for longer lines. Even under harsh ambient operating conditions, the integrated conductors ensure a reliable power supply along the entire line. And this compact profile section design can be installed the in a much shorter time.
The standards also include laser distance-measuring system and a safety bracket which immediately stops the friction-wheel travel drive of the KBK system if it runs against an obstacle. In addition, the frequency-inverter control of the friction-wheel travel drive, which is integrated into the travelling hoist control enclosure for reliable signal transmission, helps to position the bucket at a defined position above the core feed machine. This precision also ensures that the travelling hoist slows down 30 cm before it reaches its destination and then travels at reduced speed until it stops.
System more versatile in comparison
KLANN has been using components from the KBK crane construction kit for 15 years and has correspondingly optimised and adapted its transport systems to meet the individual requirements of specific customer applications.
Layout of the system for the supply of 12 core shooters
Compared with a rail-mounted installation, the overhead transport solution with its curve-negotiating KBK components is much more versatile. For example in foundries, in which the system has to adapt to existing machine layouts and the available space. Furthermore, the steel superstructure requirement is lower than for a platform, since the supports for the KBK system can be positioned at intervals of 6 m.
The sand distribution installation delivered by KLANN with the integrated KBK components supplied by Demag Cranes & Components provides tangible benefits wherever relatively small quantities of bulk goods have to be transported from place to another and where the transport routes are too narrow for Big Bags. Further benefits are offered by the installation, in which the expertise of both companies is combined into an integrated logistics solution, above all thanks to its gentle, overhead and, therefore, space-saving transport operations. Other advantages are its great versatility in terms of routing, reliable power-supply and high precision when positioning.