FI13537Y1 - Grinder - Google Patents

Abstract

A mill intended for crushing steel slag or fly ash in such a way as to separate metals and slag materials, and which mill consists of a jacket (1), a cover (2) and a base (3) and inside the mill there is a crushing element (4, 5) which steel slag and incinerator ash can be broken down, and each crushing element consists of two counter-rotating rotors; from the inner rotor (4) and the outer rotor (5) and that the material (6) can be fed into the center of the inner rotor (4), from where it is thrown by centrifugal force onto the outer rotor (5) and further below, out through the discharge openings (7) in the bottom (3), characterized by , that outside the supply pipe (8) there is another compressed air control pipe (9), which form an elongated, tubular nozzle for compressed air, which can be fed from the top (10) down between the inner rotor (4) and the outer rotor (5).

Description

Mill — Kvarn

The object of this invention is a mill intended for crushing steel slag or incineration ash in such a way that the metals and slag materials can be separated. The mill consists of a casing, a cover and a base, and inside the mill there is a crushing element, which — with the help of steel slag and combustion ash can be broken down, and which crushing element consists of two counter-rotating rotors; from the inner rotor and the outer rotor and that the material can be fed into the center of the inner rotor, from where it is thrown to the outer rotor thanks to the centrifugal force and further below, out through the discharge openings at the bottom. — Finnish patent FI 128329 shows a state-of-the-art mill. In a known method, air is fed between a rotating pipe shaft and a stationary supply pipe. In practice, it has been observed that the effect between the sealant and the pipes is not as good as when feeding between stationary pipes. If and when there is moisture inside the mill, another problem arises when the crushed substances bind to each other and to the walls of the mill.

The purpose of this invention is to further improve the operational efficiency of compressed air.

The mill according to the invention is characterized by the fact that outside the supply pipe there is another compressed air control pipe, which forms an elongated, tubular nozzle for compressed air, which can be fed from top to bottom between the inner rotor and the outer rotor.

One application form of the invention is characterized by the fact that the guide tube at the lower end of the compressed air nozzle has holes through which the compressed air can escape to the sides.

The invention is explained in the following by means of an example by referring to the accompanying drawing, in which: Figure 1 shows a mill according to the invention in cross-section and Figure 2 shows a solution of one embodiment of the lower part of the compressed air nozzle.

The mill is intended for crushing steel slag in such a way that metals and slag materials can be separated. The mill consists of a shell 1, a cover 2 and a base 3. Inside the mill — there is a crushing element, with the help of which the steel slag can be broken down. The crushing element consists of two counter-rotating rotors; from the inner rotor 4 and the outer rotor 5. The material 6 can be fed into the center of the inner rotor 4, from where it centrifugally

thanks to the force, it is thrown onto the outer rotor 5 and further below, out through the outlet openings 7 in the bottom 3. Outside the supply pipe 8, there is another compressed air guide pipe 9, which form an elongated, tubular nozzle for compressed air, which can be fed from the top 10 down between the inner rotor 4 and the outer rotor 5 —.

The problem arises when there is moisture and moist crushed waste materials inside the mill. The moisture binds the small particles of the crushed substance to each other and to the walls of the mill. The compressed air fed into the mill 10 is evenly distributed inside the crushing element and prevents the material from sticking to the walls and rotors. Compressed air helps — in transporting the crushed material through the mill and out through the discharge openings.

Figure 2.

The guide tube 9 at the lower end of the compressed air nozzle has holes 11, through which the compressed air can escape to the sides. This uniform flow of compressed air discharging to the side keeps the lower surface of the upper rotor and the crushing elements of the upper rotor clean. There can also be holes in the inner pipe, in which case the compressed air enters the material 6 supply pipe and is directed from it downwards and to the sides.

The parts of the mill are made of a suitable steel material that has both durability and toughness.

The invention is not limited to the example presented above, but may vary within the scope of the protection requirements presented below. Therefore, the mill is also suitable not only for crushing steel slag and fly ash, but also for crushing other slag materials. The separation of metals from the crushed mass is carried out by methods known per se.

For example, iron particles can be separated with a magnetic separator and other, non-magnetic metals, for example, with known chemical methods.

Claims (2)

Protection requirements 1. A mill intended for crushing steel slag or fly ash in such a way as to separate metals and slag materials, and which mill consists of a shell (1), a cover (2) and a base (3) and inside the mill there is a crushing element (4, 5) , with the help of which steel slag and incineration ash can be decomposed, and which crushing element consists of two counter-rotating rotors; from the inner rotor (4) and the outer rotor (5) and that the material (6) can be fed into the center of the inner rotor (4), from where, due to centrifugal force, it is thrown to the outer rotor (5) and further below, through the discharge openings (7) in the bottom (3) out, characterized by the fact that on the outside of the supply pipe (8) there is another compressed air control pipe (9), which form an elongated, tubular nozzle for compressed air, which can be fed from above (10) down between the inner rotor (4) and the outer rotor (5) . 2. A mill according to claim 1, characterized by the fact that the guide pipe (9) at the lower end of the compressed air nozzle (8, 9) has holes (11) through which the compressed air can escape to the sides.