AU595579B2

AU595579B2 - Hammer crusher

Info

Publication number: AU595579B2
Application number: AU68293/87A
Authority: AU
Inventors: Erkki Huhdankoski
Original assignee: Roxon Oy
Current assignee: Roxon Oy
Priority date: 1986-02-13
Filing date: 1987-02-04
Publication date: 1990-04-05
Anticipated expiration: 2007-02-04
Also published as: AU6829387A; GB2186504A; FI860663A; FI74221C; ES2003685A6; DE3704300A1; SE8700417L; FI860663A0; KR870007726A; FR2594049A1; SE8700417D0; JPS62247843A; FI74221B; GB8703208D0

Description

COMMONWEALTH OF AUSTRALIA Patent Act 21952 595579 C 0OMP LET E S PEC IF IC A TIO N

(ORIGINAL)

Class Int. Class Application Number 6 S ?q3 1 9 Lodged Complete Specification Lodged Accepted Published amnfnAestv mado wamft scciion 49 iid Gai e AWs r 1~ Priority :13 February 1986 Related Art 4C r C C~

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Name of Applicant Address of Applicant *ROXON OY *Keskikankaantie 9, 15870 Salpakangas, Finland Actual Inventor/xx Address for Service *Erkki HUHDANKOSKI RICE CO., Patent Attorneys, 28A Montague Street, BALMAIN 2041.

Complete Specification for the invention entitled: HAMMER CRUSHER The following statem~ent is a full description of this invention including the best method of performing it known to us 'fit;la The present invention concerns a. hammer crusher for crushing hard and soft substances, comprising a frame, a feed aperture for the goods to be crushed, a rotor rotatably carried in the frame and to which have been pivotally attched one or several substantially radial hammers, a drive for the rotor, and a bottom lattice set through which that material can pass which has been comminuted to small enough size.

The purpose to which a hammer crusher of this kind is used is 1 crushing hard and soft substances to desired maximum lump size and 'eparating uncrushable objects from the material being crushed, in treatment processes for solid fuels and wastes. The commonest areas of application are crushing of minerals, industrial and domestic waste and coal.

A conventional hammer crusher comprises a rotor, to which radial S hammeras are attached, a knife bridge serving as counter-edge, and S a bottom lattice set, which completely or partially covers the lower side of the crushing chamber.

c 9 The bottom lattice set usually consists of transversal rods, the gap between them defining the largest piece size of the crushed goods, or of a perforated plate, where the diameter of the perforations defines the largest piece size.

e In a hammer crusher where the bottom lattice set only encompasses c C C part of the chamber's bottom, there is no actual separation of uncrushed objects at all. Oversized uncrushed pieces leave the chamber through an aperture after the bottom lattice set.

In a hammer crusher of which the bottom lattice set encompasses the entire bottom of the crushing chamber, scrap separation is necessary. One design solution is a spring-loaded toggle flap located above the knife bridge, which opens when the hammers urge an uncrushed body along the top surface of the knives and against said i toggle flap.

Another design solution is a scrap pocket located opposite to the knife bridge, on the other side of the rotor. After passing over the bottom lattice set, the uncrushed object is flung against the roof of the scrap pocket and falls from there into the scrap pocket.

Hammer crushers of prior art are however encumbered by the drawback j of blocking of the bottom lattice set occurring when light and soft materials are being crushed, such as lump peat for instance. The kinetic energy of such light-weight material is too low to ensure that material which has become impacted in the lattice gap by effect of friction and adhesion will come off and flow properly.

The drawback of scrap separation by means of a toggle flap is that the apertures of the crusher's bottom lattice set have to be dimensioned to equal the size of the largest body which can pass through or past the knife bridge. In any other event, an uncrushable object that has entered the crusher will rotate along with the hammers in the crushing chamber and may damage the structure. On the other hand, if the bottom lattice set is made sparse, the lump size of the material coming through from the crusher will be large.

c The drawback encumbering crushers with scrap pockets, of the kind existing at present, is that as a consequence of temporary exces- 0. sive feeds the scrap pocket is filled with material to be crushed and therefore it ceases to be operative until the pocket has beem emptied.

TIP~ nhjmc-o n4-tk pnc+mnt -(Innt provip 4p hammer -crusheP which is free of the drawbacks mentioned and which th re gives more reliable and more efficient service. ammer crusher of the invention is characterized in ta he bottom lattice set is composed of a disk or r r screen with a plurality of shafts, these shafts b J so arranged that the centremost shafts are located h-n t 4Q;mrt rzhP4t r 2a According to the present invention there is provided a hammer crusher which is free of the drawbacks mentioned and which therefore gives more reliable and more efficient service. The hammer crusher of the present invention comprises a frame, a feed aperture for material to be crushed, a rotor rotatably carried in the frame and to which have been pivotally or rigidly attached one or several substantially radial hammers, a drive means for the rotor, and a bottom lattice set through which the material comminuted to be small enough can pass, whereby the bottom lattice set is composed of a disk or roller screen with a plurality of shafts being so disposed that the centremost shafts are located lower than the sidemost shafts, characterized in that the shafts of the bottom lattice set have been disposed to be rotatable.

In an embodiment of the present invention there is provided a hammer crusher, wherein the size of the largest S body passed by the crusher is adjustable by adjusting the separation limits of the screen constituted by the bottom lattice set.

C S to Ii A 4. I 4e. t k ,-mnwv e r:tcr.CQlZ. .i4- I-k Q.is characterized in that each shaft of the bottom lattice se as the same distance from the rotor axis, whereby all shaft are located on a circular arc having the rotor axis for /ts centre.

Another advantageous embodiment of the inyv tion is characterized in that the shafts of the bottom latt' e set have been disposed to be rotatable and that the distan of these shafts from the rotor axis has been arranged to b such that as the rotor rotates the hammer tips keep the b -om lattice set clean.

One more adva lageous embodiment of the invention is characterized in that e size of the largest body passing through the crusher is adj able by adjusting the separation limits of the screen consti- L* 4. 4k4 i t i I s, -1 LL I: II l Numerous advantages over crushers of prior art are gained with a hammer crusher of this kind: among others, non-blocking when crushing stringy or sticky waste containing fibres, wet and abundantly clay-admixed coal and fuel conatining peat. The crusher only passes bodies which are smaller than the desired maximum lump size. In addition, the crusher separates the uncrushable bodies exceeding e the desired maximum lump size from those which are crushable,

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c independent of the design of the knife bridge. A special application, which is not feasible with a conventional hammer crusher, is S such treatment of coal with abundant country rock that the coal t" contained in the feed is crushed with a fairly low peripheral velocity of the hammer, whereby the harder rock material is not crushed and is instead flung into the scrap pocket and discharges

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E 30 therefrom as screen plane overflow.

Among other advantages may be mentioned the fact that the scrap pocket does not fill up and that the scraps can be directly passed onto a scrap conveyor. There will also be no crushed material entrained with the scrap, for instance during temporary overload conditions. In addition, oversized pieces are crushed to some extent as they hit against the roof of the scrap pocket, whereby the proportion of oversized pieces in the scrap is reduced.

I I 4 When the bottom lattice set consists of a roller screen, accumulation of extremely sticky material on the roller surface, building up an increasing layer, can be prevented by setting the position of the rotor in relation to the rollers to be such that the tip of the hammer passes very close to the roller surface, at the same time detaching any material sticking to the roller surface. When the bottom lattice set consists of a disk screen set, blocking of the screen set can be prevented by such positioning of the rotor that the tips of the hammers enter the space between the disks, whereby the hammers will clean the screen set as the rotor rotates.

The invention is described in greater detail in the following, referring to the attached drawing, wherein Fig. 1 presents, schematically and in section, a hammer crusher according to the invention and the scrap pocket connected therewith.

Fig. 2 shows the section slong the line II-II in Fig. 1.

In Fig. I has been depicted a hammer crusher provided with a bottom Slattice set and with a scrap sorter, this crusher consisting of a j frame 1, in which a rotor 2 has been rotatably carried. To the J rotor have been attached hammers 3. The lower part of the crusher consists of a set of roller or disk screens 12 serving as bottom e 'ri lattice set and which has been constructed in circular arc configuration and consists of a plurality of side-by-side screen rollers, preferably arranged to be rotatable. The rotor is driven, as shown ct in the figure, by a motor 5, which usually is an electric motor but which may equally be an internal combustion engine, a steam engine, or equivalent.

The shafts 4 of the roller or disk screen in the lower part of the crusher are rotatably carried in the frame 1 of the crusher, and the shafts of the screen are rotated either by a drive 6 provided with a motor of its own or by a drive deriving its power from the drive 5. The bottom of the scrap pocket 10, which consists of a chamber, is formed by a screen, preferably a roller or disk screen, serving as scrap screen 7, its rollers being rotated by a drive 8 provided with a motor of its own or by a drive which is common with the roller or disk screen set in the lower part of the crusher, or by a drive deriving its power from the drive The shafts 4 of the roller or disk screen in the lower part of the crusher may rotate either clockwise or counter-clockwise. The shafts of the roller or disk screen in the scrap pocket 10 rotate I clockwise, whereby they transport the material t1qi- has been flung onto the screen set, out from the scrap pocket. The rotary motions of the roller or disk screen sets are interconnected with the aid of a roller chain, gearwheel, serrated belt, or other belt transmission. Each shaft may equally be driven by a drive of its own, for instance by a hydraulic motor.

The material to be crushed is fed in from above the crusher's rotor S2. The material comminuted by the hammers will be screened through the bottom lattice set 12, and oversized pieces are subjected to repeated impacts.

Uncrushed objects are flung against the roof of the scrap pocket and fall down from there onto the scrap screen 7. Of the material which has travelled into the scrap pocket, oversized and uncrushed j8 objects are discharged as overflow from the scrap screen. The size of the largest body passed by the crusher is adjusted by adjusting c the separation limit of the bottom lattice set and of the scrap screen.

It is obvious to a person skilled in the art that the invention is not confined to the embodiment examples presented in the foregoing and that it may be varied within the scope of the claims following below. For instance, a hammer crusher with stationary lattice may equally be fitted with a scrap separator as taught by the invention. The rotating set of lattices may also be implemented in a hammer crusher with vertical shaft. In that case, the crusher chamber is defined by vertical shafts of the roller or disk screen, which rotate when the crusher is in operation. In this instance, 6 Sthe material to be crushed must not corntain any uncrushable objets.

Claims

1. A hammer crusher for crushing ha'rd and soft substances, comprising a frame, a feed aperture for material to be crushed, a rotor rotatably carried in the frame and to which have been pivotally or rigidly attached one or several substantially radial hammers, a drive means for the rotor, and a bottom lattice set through which the material comminuted to be small enough can pass, whereby the bottom lattice set is composed of a disk or roller screen with a plurality of shafts being so disposed that the centremost shafts are located lower than the sidemost shafts, characterized in that the shafts of the bottom lattice set have been disposed to be rotatable.

2. Hammer crusher according to claim 1, characterized in that the size of the largest body passed by the crusher is adjustable by adjusting the separation limits of the screen constituted by the bottom lattice set.

3. A hammer crusher for crushing hard and soft substances substantially as hereinbefore described with reference to any one of the accompanying figures. DATED this 29th day of November 1989 ROXON OY l t ^Patent Attorneys for the Applicant: c r F.B. RICE CO. A «M' I I- C