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Title:
A SYSTEM FOR THE MACHINING OF INERT MATERIALS FOR THE PRODUCTION OF SAND OR GRANULATES IN GENERAL, APPLICABLE TO THE ROTORS OF BOTH REVERSIBLE AND NON-REVERSIBLE HAMMER MILLS
Document Type and Number:
WIPO Patent Application WO/1993/003845
Kind Code:
A1
Abstract:
A system for the machining of inert materials for the production of sand or granulates in general, applicable to the rotors of both reversible and non-reversible hammer mills, being characterized by the fact that there is a single hammer (1) and that its weight is counterbalanced by a balance weight (3), located diametrically opposite the hammer and in such a manner as to not interfere with the material which is undergoing treatment, i.e., which does not protrude within the material crushing area (5).

Inventors:
Paolini, Michele
Application Number:
PCT/IT1992/000102
Publication Date:
March 04, 1993
Filing Date:
August 11, 1992
Export Citation:
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Assignee:
DI PAOLINI MICHELE & C
Paolini, Michele
International Classes:
B02C13/28; (IPC1-7): B02C13/28
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Claims:
C L A I M S
1. A system for the machining of inert materials for the production of sand or granulates in general, applicable to the rotors of both reversible and nonreversible hammer mills, being characterized by the fact that there is a single hammer (1) and that its ωeight is counterbalanced by a balance ωeight (3), located diametrically opposite thε hammer and in such a manner as tn not interfere ωith thε material ωhich is undergoing treatment, i.e., ωhich does nnt protrude ωithin the material crushing area (5) . 0.
2. A system according to claim 1, being characterized by the fact that the hanmer (1) is carried by the rotor (•+) and housed inside a haπmerhαlder (2), the haimer (1) being in the hanmer holder (2) and this, in turn, being housed in the rotor (* by 5 means of dovetail joints.
3. A system, according to claim 1, being charactεrizεd by thε thε fact that the balance ωeight (3) has the same shape and sizε as the hammerholder and is fitted in the rotαr (*.) by means of D a dovetail joint and is providεd ωith shapεd παtchεs likε thε haπmerhαlder, on its back ωhεre it is possible to place slips (12) in order to modify its ωeight and adapt it to the lessening ωεight αf the hammer, due to ωear . A system, according to claim 1,being characterized by the fact that protective elements (1*.) have been provided for the rotor (4), these are placed diametrically opposite and εqui diπstant, ωith respect to both the hanmer and the balaπcε ωeight; said protεctivε elements (14) bεing fittεd on thε rαtαr ωith thε same means as the hanmer and the balance ωεight and not interfering, exactly like thε balancε ωεight, ωith thε ma tεrial ωhich is being machined .
Description:
DESCRIPTION

A system far the machining of inert materials fDΓ the production of sand or granulates in general, applicable to the rotors of both reversible and non-reversible haimer mills.

Technical Field

The object of this invention concerning the improvement of reversible and παn-ruversible haimer mills, is to reduce the dimensions and, therefore, the ωeight of the mill and at the same time to increase its production capacity and, conse¬ quently, its efficiency, although keeping its peripheral speed unchanged . Background Art

It is a ωell-kπαωπ fact that in the case of reversible and non-reversible hamπer mills for the machining of inert materials, for the production of sand and granulates in general, the in¬ troduction into the mill of the materials to be crushed is li¬ mited by the movement of the hammers. Another uiεll-knoωπ fact is that , in order to enable the mill to function ωith rεgu- larity, the haππers must be even in number and placed diame¬ trically opposite one another. The more hammers there are, the more time is required for loading the material to be crushed and, therefore, the less material is produced. One solution ωhich has been attempted, keeping the angular velocity αf the rotor unchanged has been to employ larger sized hammers,thus increasing both their ωeight and pouier; nevertheless, to date, the problem αf lαadiπg the mill in a complete and speedy manner, at the same time avoiding the excessive ωεar of the banners,

has yet to be sπlved .

Furthermore, another ωell-knoωπ draωback of haimer mills is the ωεar, not only of the hammers, ωhich is natural, but also of the rotor, due to the presence of the granulates in the envirorment in ωhich the rotor uiorks and to the necessity tα involve the rotor in the replacement of ωαrπ haimers, ωhich are mounted directly on it.

Disclosure of Invention

The mill, according _D the invention, is provided ωith a single hammer, the balancing of ωeights during the rotation being achieved by means αf a balance ωeight placed diametri¬ cally opposite the hammer and in such a position as not to interfere ωith the material being machined by the mill. Said balance ωeight, the sole function of ωhich is to balance the ωeight of the haimer, does not have any role ωhatsoever in the crushing of the material introduced inside the mill.

Given the presence of a single hammer, the time ωhich is πoω available for the introduction of the material to be machined is practically doubled, compared to the time required in the case of normal hanmer mill provided ωith tωo or more haimers .

Furthermore, according to this invention, the hanmer consists of tωo parts, the hanmer itself and the haπmer-holder, the latter and the balance ωeight preferably having the sane shape and size so as not to require specific and diverse manufacturing procedures. It also provides for specific techniques for assεsnbliπg the hanmer and for the replacement of ωorπ hammers, the selfsame being valid far the balance ωeight also.

According the one possible variation nf this invention,the rotor is provided ωith protective elements against ωear, elements ωhich are not involved in the crushing of the materials, exactly

likε the balance ωεight .

This invention may be better understood by reading the following description and by making reference to the attached illustrations: Figure 1 shoωs an outline of the mill rotor, according to this iπvεπtiαn, thε dαttεd lines shouting thε circumfεreπces traced by the hanmer and the balance ωeight and, therefore, their areas of influεπce. Figure 2 shαωs a detail αf hαω the hanmer is mounted in its holder and hαω the latter is then fitted onto the rotor; the sane system also applying to thε balance ωεight and to the balance ωεight's protectivε elements .

Figure 3 shoωs a passible variation αf thε solution shown in figurε 1. ϋJith reference to said dra ings and, in particular, to fig.1, the mill spεcifiεd in this invention consists αf an external body, provided ωith an inlet for thε introduction αf the mate¬ rial to be crushed (ωhich is not shown in the figure) and a rotor, shown ωith number k. According tα this invention, a single hammer 1 is mounted onto thε rotor, said haimer bεing housed in a specific holder 2, ωhile the balance ωεight 3, lαcatεd diametrically αppositε to the hanmer 1, is preferably of the sane shape and sizε as thε hanmεr-hαldεr 2 and the aim αf ωhich is tα balance the ωεight αf thε haimer 1. As may bε sεεn in fig. 1, the balance ωεight 3 protrudes from thε rotor

4, in such a manner as not to interfere ωith the crushing area

5, but is limited to the circumference 6, ωhich is the same circumference described by the hammer-holder 2, therefore, neither the one, nor the other intεrfεrε ωith thε crushing operations.

As may be seen in fig. 2, the haπmer-hαlder 2 and the balance ωeight 3, shαωn in fig. 1 and mounted DΠ the rotor * by means Df bolts 7 or similar means, are preferably formed by a body 11, the inside end Df ωhich, i.e., the end which is to be fitted onto the rotor, is dovetailed, so that it may fit exactly into a corresponding space on the rotor. In this manner, the haπmer-hαlder and the balaπc" ωeight oppose the centrifugal force cαπ unicated by the rotation αf the rotor. Similarly and for the same reason, the end part 12 of the hammer 1, is also shaped in such a manner as to fit in thε dovetailed part of its holder 2. Consequently, the hammer-holder 2 and the balance ωeight 3 are shaped in the sane manner and also have the same size,inclu¬ ding the hεad cavity 15, thus greatly simplifying the manufactu¬ ring αf the rotor k and of the hanmer-holder and balance ωeight, ωhich are fully interchangeable. Furthermore ,as may be seen in Fig. 3, as the hammer 1 is subject to ωear, ωhilε the balance ωeight 3 is not, the invention has provided for the application, preferably on the back of thε balancε ωεight 3, of a series αf slips 12, easily removable, far example, by untightening the bolt 13, so as to change their πunber and, consequently, gradually modify the ωeight of the balance ωεight 3, as the ωeight of the hammer 1 gradually decreases due tα ωear .

Lastly, it must be painted out that, in order to protect the rotor from ωear, due to the impact of the granulated material,thε iπvεntion has provided for the protective elεmεπts 1*+, placεd diametrically and at 90 degress to thε hammer 1 and the balance ωeight 3 and preferably fastened ωith the same system as the hanmer-holder 2 and the balance ωεight 3. Neither do these protective elements Λh αf the rotor k interfere ωith thε crushing area 5, but rotate only ωithiπ the arεa 6, around thε

rαtαr k .

The advantages offered by this invention are obvious. In par¬ ticular , it must bε pαiπtεd out that, .givεn the presence of a single hammer, the lαadiπg time and crushing εfficiεncy are considerably increased, at least doubled, compared to con¬ ventional hammer mill ωith tωo or more hammer and, especially, of mills featuring a high peripheral speed. Furthermore, the centrifugal force generated by the movement πf the rotor is effectively contrasted, ωhile, at the same time, it is extrεmεly εasy tα remove and replace all worn parts and the rαtαr and the hanmer-hαldεr are effectively prαtectεd, themselves, against ωear. Thε mill, thεrεfare, is much mare effective and may.._iDrk for much longer periods, rεquiring much shorter pεriods αf time for the replacement αf thε worn components .