US1133212A - Roll-mill for hard materials. - Google Patents

Description

H. ALDEHOFF.

ROLL MILL FOR HARD MATERIALS.

APPLIGATION FILED 1111.19, 1914.

2 SHEETS-SHEET 1.

WITNESSES INVENTOR HERMANN ALDE HOFF BY ,l a ATTORNEYS Patented Mar. 23, 1915.

H. ALDEHOFF.

ROLL MILL FOR HARD MATERIALS.

APPLICATION FILED JAN. 19, 1914.

L1 33 mm Patented Mar.23,1915

2 SHEETS-SHEET 2.

WITNESSES INVENTOR HERMANNALDEHOFF A TORNEYS HERMANN ALDEHOFF, 0F BERLIN, GERMANY.

ROLL-MILL For. HARD MATERIALS.

Application filed January 19, 1914.

To all whom it may concern Be it known that I, HERMANN ALDnnorF, a subject of the King of Prussia, residing at Berlin, in the Kingdom of Prussia and German Empire, have invented new and useful Improvements in Roll-Mills for Hard Materials, of which the following is a specification.

In roll-mills for hard material constructed on the Kent and MaXecon system the grinding ring is closed laterally by rings arranged at about 5-10 mm. fromthe grinding ring. As the grinding ring in rotatlng moves somewhat laterally, a space of as much as 15 mm. can occur between one side of the grinding ring and the corresponding disk. Through this space pieces of 57 mm. and more can fall without being subjected to the action of the rolls. For the purpose of lifting these pieces the mills heretofore used are provided with an elevator. With the object of overcoming this drawback plates are secured to the sides of the grinding rlng, which plates nearly reach the shafts carrying the rolls and are provided with perforations. These sieves have such a shape that circumferential mantle surfaces are formed, through which the material passes under the influence of the circumferential force.

In order to assure that the fine material leaves the mill behind the first roll and does not pass with the coarse material to the second roll, where it would only impair the grinding action, a guide piece is provided in the grinding ring behind the roll to Which the material is first led, said guide piece having a roof like shape as seen from the side, preferably also as seen from the front, and a wedge shaped front end. The operation of this guide piece is explained below.

A mill constructed according to the 1nvention is shown by way of example in the drawing.

Figure 1 is a vertical cross section, and Fig. 2, a vertical longitudinal section through the mill, Fig. 3 shows a pla n of the guide piece arranged in the grlnding mill between the first and second rolls.

The grinding ring a; is carried by the uppermost roll 6 which serves as a friction roll and drives the ring. To the sides of the ring a are attached the plates 0, which from the grinding surface cl are bent inward and then parallel with the side flanges of the ring. These plates are perforated, 1n order to allow the fine ground material to pass Specification of Letters Patent.

Patented Mar. 23%, 1911.5.

Serial No. 813,045.

through. In order to better remove the fine material ventilators can be attached to the casing (2 outside of the plates 0. The guide piece f hasa roof-like cross section (Fig. 1), preferably also a rooflike longitudinal sect1on (Fig. 2-), while its front end .9 has a wedge shape. The wedge shaped end 9 conducts the material coming from the first roll b toward opposite sides, thus out of the grinding ring a into the sieves c. As however these sieves are inclined the material not passing through the same falls back agaln and thus arrives between the second roll 6 and the grinding ring. The fine material is also thrown by the roll 6 onto the roofiike guide piece and is led by the form of this piece to the sieves, through which 1t passes in order to leave the machine. The material falling from the roll 6 is also directed by the guide piece 1'' toward the sieves.

The wedge shaped front end 9 serves simultaneously as scraper to remove all material adhering to the grinding ring. The opposite end it of the guide piece 7 is adapted to the shape of the roll Z2 but need not touch the same. The guide piece 7 is kept in position by lugs 2' having holes through which bolts 72 pass, the ends of which are secured to the side plates of the casing.

The advantage of this mill will be clear from the fact that the existing mills of this kind have an output 0f 17 50 kilograms of finished cement per hour when 20,000 kilograms of raw material are passed through the mill, while in the new mill an output of 3500 kilograms of finished cement is obtained when only 10,000 kilograms of raw material are assed through the machine. This increase output is explained by the fact that the rolls and grinding ring are kept free from fine material, so that the material which is still coarse is not subjected to the grinding action in a bed of fine material. A further advantage of the inven tion is that the transort apparatus has less material to deal wit 1, so that less power is required.

What I claim and desire to secure by Letters Patent of the United States is 1. The grinding mill for hard materials, comprising in combination, a grinding ring, grinding rolls inside said grinding ring, sieve-plates attached to the sides of said grinding ring and bent to form a circumferential mantle, a guide piece inside said ring behind the first of said grinding rolls,

said guide piece'having a roof shape in cross section and a wedge shaped front end, substantially as, and for the purpose, set forth.

2. The grinding mill for hard materials,

' comprising in combination, a grinding ring,

grinding rolls inside said grinding ring, sieve-plates attached to the sides of said grinding ring and bent to form a circumferential mantle, a guide piece inside said ring behind the first of said rolls, said guide piece having a roof shape in cross section,

a roof shape in longitudinal section and a wedgexshaped front end, substantially as, and for the purpose, set forth.

3. A grinding mill for hard materials, comprising a grinding ring, an upper grind- Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

- Washington, D. G."

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