EP3922355A1

EP3922355A1 - Horizontal hammer mill

Info

Publication number: EP3922355A1
Application number: EP21178676.9A
Authority: EP
Inventors: Mauro Panizzolo
Original assignee: Panizzolo Srl
Current assignee: Panizzolo Srl
Priority date: 2020-06-11
Filing date: 2021-06-10
Publication date: 2021-12-15
Anticipated expiration: 2041-06-10
Also published as: IT202000013966A1; EP3922355B1; EP3922355C0

Abstract

A horizontal hammer mill (10) for milling material, which comprises:
- a housing (11) with a substantially cylindrical shape, which defines inside it a milling chamber (12), the housing (11) having an inlet (15) for the material at a first axial end (16), and an outlet (17) for the material at a second axial end (18),
- a rotating shaft (13), inside the housing (11) and coaxial therewith, a plurality of hammers (14) being keyed on the rotating shaft (13); and
-means (19) that are adapted to produce an action propelling the material from the inlet (15) toward the outlet (17).

Description

The present invention relates to a horizontal hammer mill.
Nowadays, for the disposal and recycling of refuse, "hammer mills" are widely used.
Hammer mills are used to mill refuse and reduce it to fragments or scraps that can then be sifted for the purpose of recovering therefrom the different types of material such as, for example, plastic and metals.
A hammer mill is an apparatus that comprises a milling chamber, contained inside a housing with a substantially cylindrical shape, inside which there is a rotating shaft on which a plurality of hammers is keyed.
The hammers are arranged in a radial direction with respect to the axis of the rotating shaft, generally in series and mutually parallel.
The refuse is introduced into the milling chamber via a loading hopper.
An electric motor, from which the rotating shaft extends, or which is connected to the rotating shaft via a transmission belt and a pulley, turns the rotating shaft, which, in turn, entrains the hammers that are keyed thereon.
By virtue of the impacts caused by the hammers beating on the refuse, the latter is shattered.
Hammer mills can be distinguished substantially in two types:

vertical hammer mills, in which the rotating shaft has a vertical axis of extension;
horizontal hammer mills, in which the rotating shaft has a horizontal axis of extension.

Considering horizontal hammer mills, the refuse is generally introduced into the milling chamber, through an inlet duct, connected to the housing, which leads into/proximate to the upper portion of a first axial end of the housing, and is ejected, in fragments, from an outlet duct, connected to the housing, at the axial end thereof opposite to the previous one.
The expression "axial end" in the present description means an end of the housing, taking its axis of extension as a reference.
In order to facilitate the coming out of the scraps from the milling chamber, downstream of the outlet there is a suction device, which is fluidically connected to the outlet duct and is adapted to suck the scraps out of the milling chamber.
Such known art has a number of aspects that can be improved.
In fact, the refuse entering the milling chamber moves by gravity and tends to become packed and remain stuck in the space comprised between the inlet into the milling chamber and the first series of hammers, toward the corresponding inner edge of the housing, downward, below the inlet into the milling chamber.
In the present description, the expression "first series of hammers" means the first series of hammers that the refuse encounters, on entering the milling chamber, moving in the direction of the outlet.
The packing of the refuse means that it is not fully milled, because there is a portion of it that becomes packed and is not milled, and/or it leads to milling operations that are long, inconvenient and wasteful of energy.
Furthermore, the packing of the refuse causes a considerable wear of the hammers, in particular of the hammers in the first series which strike material that is progressively more cumbersome and massive, and a consequent considerable overheating.
Also, the packing of the refuse can, in some cases, lead to the obstruction of the inlet, with consequent interruption of processing.
The aim of the present invention is to provide a horizontal hammer mill that is capable of improving the known art in one or more of the above mentioned aspects.
Within this aim, an object of the invention is to provide a horizontal hammer mill in which the material does not pack/get stuck inside the milling chamber.
Another object of the invention is to provide a horizontal hammer mill that is subject to less wear and overheating with respect to similar, conventional hammer mills.
A further object of the present invention is to overcome the drawbacks of the background art in a manner that is alternative to any existing solutions.
Another object of the invention is to provide a horizontal hammer mill that is highly reliable, easy to implement and of low cost.
This aim and these and other objects which will become better apparent hereinafter are achieved by a horizontal hammer mill for milling material, which comprises:

a housing with a substantially cylindrical shape, which defines inside it a milling chamber, said housing having an inlet for said material, at a first axial end, and an outlet for said material, at a second axial end,
a rotating shaft, inside said housing and coaxial therewith, a plurality of hammers being keyed on said rotating shaft,

Further characteristics and advantages of the invention will become better apparent from the detailed description that follows of a preferred, but not exclusive, embodiment of the horizontal hammer mill according to the invention, which is illustrated for the purposes of non-limiting example in the accompanying drawings wherein:

Figure 1 is a side view of a horizontal hammer mill, according to the invention;
Figure 2 is a partially cross-sectional view of the hammer mill of Figure 1.

With reference to the figures, a horizontal hammer mill, according to the invention, is generally designated by the reference numeral 10.
The mill 10 comprises a housing 11 with a substantially cylindrical shape, which defines inside it a milling chamber 12.
Inside the housing 11, and therefore inside the chamber 12, is a rotating shaft 13, coaxial with the housing 11.
A plurality of hammers 14 is keyed on this rotating shaft 13.
The housing 11 has:

an inlet 15 for the material (the latter not shown in the figures), at a first axial end 16 thereof,
an outlet 17 for the material, at a second axial end 18 thereof, opposite to the previous one.

This inlet 15 is arranged at/proximate to the lower portion of the first axial end 16.
Preferably, the inlet 15 is arranged in a region below the rotating shaft 13.
Similarly, this outlet 17 is arranged at/proximate to the lower portion of the second axial end 18.
The mill 10 comprises motor means 23 for the movement of the rotating shaft 13.
The motor means 23 comprise an electric motor, not shown in the figures, which is kinematically connected to a transmission belt 24, which is in turn connected kinematically to a pulley 25, the latter being keyed on the rotating shaft 13.
The mill 10 comprises means 19 that are adapted to determine an action propelling the material from the inlet 15 toward the outlet 16.
In particular, the mill 10 comprises a hopper 20 for loading the material, which is connected to a first duct 21, for entry, which is in turn connected to the inlet 15.
In a further embodiment, not shown in the figures, the duct 21 is inclined by approximately 40°-45° in order to facilitate the rolling of the material toward the milling chamber 12.
The mill 10 comprises a second exit duct 22, which is connected to the outlet 17.
These means 19 adapted to produce a propelling action are, for example, pneumatic conveyance means which comprise a blower.
The means 19 adapted to produce a propelling action are fluidically connected:

to the first duct 21, upstream of the hopper 20, as shown in Figures 1 and 2,
and/or to the inlet 15, in a further of embodiment not shown in the figures.

During the processing, the means 19 adapted to produce a propelling action generate an air flow, using the blower, which exerts a propelling action on the material entering the milling chamber 12.
This blower is, for example, of the VM400/N2 type from the company MZ ASPIRATORI of Budrio (BO), Italy.
The mill 10 comprises, downstream of the outlet 17, suction means, not shown in the figures, which are fluidically connected to the outlet 17 and/or to the second duct 22.
The operation of the horizontal hammer mill 10, according to the invention, is the following.
The material to be milled, such as for example refuse to be recycled, is sent to the milling chamber 12 starting from the hopper 20, through the first duct 21 and the inlet 15.
By virtue of the action of the means 19 adapted to produce a propelling action and of the position of the inlet 15, the material introduced into the milling chamber 12 does not become packed/get stuck, but is pushed in the direction of the outlet 17.
The material therefore passes through the milling chamber 12, being fragmented by virtue of the action of the hammers 14, which are made to move by the rotation of the rotating shaft 13.
Then, the fragmented/milled material exits from the milling chamber 12, through the outlet 17 and the second duct 22, aided by the suction means.
In this manner, by virtue of the means 19 adapted to produce a propelling action and of the position of the inlet 15, the material does not become packed/get stuck, and less wear and overheating is generated on the hammers 14 and on the shaft 13, with respect to similar, conventional horizontal hammer mills.
In practice it has been found that the invention fully achieves the intended aim and objects by providing a horizontal hammer mill in which the material does not become packed/get stuck inside the milling chamber.
With the invention a horizontal hammer mill has been devised that is subject to less wear and overheating with respect to similar, conventional hammer mills.
The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims. Moreover, all the details may be substituted by other, technically equivalent elements.
In practice the materials employed, provided they are compatible with the specific use, and the contingent dimensions and shapes, may be any according to requirements and to the state of the art.
The disclosures in Italian Patent Application No. 102020000013966 from which this application claims priority are incorporated herein by reference.
Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

A horizontal hammer mill (10) for milling material, which comprises:
- a housing (11) with a substantially cylindrical shape, which defines inside it a milling chamber (12), said housing (11) having an inlet (15) for said material, at a first axial end (16), and an outlet (17) for said material, at a second axial end (18),

- a rotating shaft (13), inside said housing (11) and coaxial therewith, a plurality of hammers (14) being keyed on said rotating shaft (13),
s characterized in that it comprises means (19) that are adapted to produce an action propelling said material from said inlet (15) toward said outlet (17).
The mill (10) according to claim 1, characterized in that said inlet (15) is arranged at/proximate to a lower portion of said first axial end (16).
The mill (10) according to one or more of the preceding claims, characterized in that said inlet (15) is arranged in a region below said rotating shaft (13).
The mill (10) according to one or more of the preceding claims, characterized in that said outlet (17) is arranged at/proximate to a lower portion of said second axial end (18).
The mill (10) according to one or more of the preceding claims, characterized in that it comprises a hopper (20) for loading said material, which is connected to a first duct (21), said first duct (21) being in turn connected to said inlet (15).
The mill (10) according to one or more of the preceding claims, characterized in that it comprises a second duct (22) which is connected to said outlet (17).
The mill (10) according to one or more of the preceding claims, characterized in that means (19) adapted to produce a propelling action are pneumatic conveyance means which comprise a blower.
The mill (10) according to one or more of the preceding claims, characterized in that said means (19) adapted to produce a propelling action are fluidically connected:
- to said first duct (21), upstream of said hopper (20),

- and/or to said inlet (15).
The mill (10) according to one or more of the preceding claims, characterized in that it comprises, downstream of said outlet (17), suction means which are fluidically connected to said outlet (17) and/or to said second duct (22).
The mill (10) according to one or more of the preceding claims, characterized in that it comprises motor means (23) for the movement of said rotating shaft (13), said motor means (23) comprising an electric motor which is kinematically connected to a transmission belt (24), said transmission belt (24) being kinematically connected to a pulley (25), said pulley (25) being keyed on said rotating shaft (13).