Casting extrusion ingots
Below, we will continue to review the plant foundry equipment for production of aluminum profiles, as it appears in the company's outstanding leadership Ashford Engineering Services. This guide is written in the late 1990s, but still it has not lost its relevance.
See. also The composition of foundry equipment
The most important equipment of such a foundry is a casting machine for casting extrusion ingots.. Usually this casting machine for vertical casting. horizontal ingot casting machines are used less frequently and, primarily, in Japan.
The composition of the vertical casting machine
The vertical casting machine for casting extrusion ingots-pillars for pressing usually includes the following main parts:
- movable casting platform, on which the seeds are installed;
- platform motion drive, hydraulic or cable;
- casting table with installed molds;
- cooling water supply system;
- control system.
The casting machine is installed in the casting pit. The casting pit is typically a concrete structure, whose walls sometimes is lined with steel plates.
Three types of vertical casting machines
There are three main types of casting machines:
- cable;
- hydraulic;
- parachute type.
All three types of casting machines can have the same types of mold table and the same types of water cooling systems.
The amount of water per minute can be estimated value 0,27 liters per millimeter perimeter of the ingot in millimeters. The value obtained is very approximate: local climatic conditions and the temperature and chemical composition of the cooling water can significantly affect the total water consumption..
Rope casting machine
The figure 1 shows a tether casting machine. Machines of this type have a capacity of up to 5000 kg and are therefore placed in small foundries. The advantage of these casting machines is, they have low cost, It requires a minimum of construction and easy to install. Performance 5000 kg - about 16 pole diameter 152 mm and length 6 m.
Figure 1 - Rope casting machine
Rope casting machines have a platform, which is raised and lowered by a cable, which is driven by the movement of the winch. Typically, such machines have a device for controlling cable tension, to compensate for its tension when the platform is increasing the weight of ingots during casting and to provide the necessary cable tension.
In case of emergency power cut usually provide a backup power supply for a while about 5 minutes, to safely complete the casting of ingots.
Because the machine has an electric drive, it is important to provide a backup source of electricity for a period of about 5 minutes, as well as a backup water source.
Hydraulic casting machine
Hydraulic casting machines are best suited for the casting of pillars with a weight of more cages 10000 kg. These machines are used for raising and lowering the platform hydraulic cylinder with a piston.
Back in the 1990s, the industry standard was a simple hydraulic cylinder with a piston with guide rails, which aligns with the movement bars platform. These guide rails attached to the wall of the casting pit, and the platform was guiding slides or rollers, which moved along the guide rails.
Already in the 2000s throughout the world, installed hydraulic casting machines with self-guiding piston hydraulic cylinders. These hydraulic actuators are strong enough, to support and guide the platform without the aid of the lateral guides. Self-directed hydraulic cylinders are very effective, but also very expensive. Without outer guide inner guiding device require increasing the diameter of the hydraulic cylinder, and in general, this design has become more expensive.
A compromise is to use as low a hydraulic cylinder with an outer guide rail, which prevents unwanted cranking platform. The figure 2 shows such a structure vertical casting machine with a folding table casting performance 60 tons for casting ingots for rolling.
Figure 2 - The hydraulic casting machine
Caster parachute type
The figure 3 shows a vertical casting machine so-called parachute type.
Figure 3 - Casting machine type parachute
(to enlarge click on the picture)
This machine platform with bars suspended on four wires of the same length. Parachute machine type does not require any equipment, which would have to be installed in the well below the foundry shop floor level.
cable system is designed, that in order to raise and lower the platform does not require lateral guides.
In case of emergency power cut usually provide a backup power supply for a while about 5 minutes, to safely complete the casting of ingots.
It is also important to provide a backup source of water in case of emergency power cut.
Source: Materials from Ashford Engineering Services, 1997
