WO2006043868A1

WO2006043868A1 - A granulator

Info

Publication number: WO2006043868A1
Application number: PCT/SE2005/001490
Authority: WO
Inventors: Kurt SJÖBERG
Original assignee: Rapid Granulator Ab
Priority date: 2004-10-20
Filing date: 2005-10-10
Publication date: 2006-04-27
Also published as: SE528762C2; SE0402553L; SE0402553D0

Abstract

The disclosure relates to a granulator with a granulator housing (3) which has a rotor (11) with a number of rotary knives (12) and stationary knives (9) mounted by means of a clamping device (10) on the granulator housing (3). With the aid of operating means (13) on the clamping device (10), the stationary knives (9) may be fixedly clamped and released from the outside of the granulator housing (3). Each clamping device (10) extends through openings (19, 35) in the side wall (4) of the granulator housing and includes a support member (17) and a clamping jaw (18). The support member (17) is fixed in relation to the granulator housing (3) and the clamping jaw (18) is movable in relation to the support member (17). On clamping of a stationary knife (9) in place, the outer portion (23) of the clamping jaw is urged away from the outer portion (24) of the support member, which entails that the clamping jaw (18) cooperates with the opening (19) in the granulator housing (3) and obtains a rocking or tilting movement. The rocking movement entails that the inner end (25) of the clamping jaw is urged against the inner end (26) of the support member and by such means fixedly clamps the stationary knife (9).

Description

A GRANULATOR

TECHNICAL FIELD

The present invention relates to a granulator comprising a granulator housing with a number of stationary knives, a rotor which is rotary in the granulator housing and displays a number of knives, the granulator housing having an infeed section and a discharge section with a grid through which ground material passes.

BACKGROUND ART

There are numerous different types of granulators in the art and these are used extensively within the plastics industry for comminuting plastic waste deriving from manufacturing as well as recycled waste. As a result, the recycling and recovery of plastic material is made possible, and both economical and environmental advantages may be attained.

Within the plastics industry, a granulator is often placed at each plastic forming machine in which small plastic pieces, for example ingots or defective parts are ground down.

The most commonly occurring fixed knives in granulators are elongate with a longitudinal edge on one side. The knives also display oblong holes which are sited with uniform spacing along the blade of the knife. The knife is mounted inside the granulator housing by means of screws that are secured in the oblong holes. With the aid of the oblong holes, the fixed knives may be adjusted in relation to the rotary knives on the rotor. Assembly and clamping of the fixed knives functions satisfactorily as long as they are mounted in large sized granulators.

On mounting in small granulators, the above-described clamping of the fixed knives functions poorly because of the lack of space. Thus, the clamping and adjustment of the knives will be circumstantial and difficult, since there is little freely available space for the operator's hands and tools inside the granulator housing. PROBLEM STRUCTURE

The present invention has for its object to design the granulator intimated by way of introduction so that the drawbacks inherent in prior art technology are obviated, in particular in small-sized granulators. In particular, the present invention has for its object to realise a granulator which displays a small granulator housing in order to be able to realise a small and compact granulator. Thus, the intention is also to realise readily accessible and stationary knives that may readily be adjusted or replaced.

SOLUTION

The objects forming the basis of the present invention will be attained if the granulator intimated by way of introduction is characterised in that the stationary knives are each disposed in a clamping device which extends through the wall of the granulator housing and which displays on its outside operating means for clamping and releasing the knife interiorly in the granulator housing.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The present invention will now be described in greater detail hereinbelow with reference to the accompanying Drawings. In the accompanying Drawings:

Fig. 1 is a vertical cross section of a granulator with a granulator housing;

Fig. 2 is a perspective view of the granulator housing;

Fig. 3 is a side elevation of a clamping jaw;

Fig. 4 is a perspective view of the clamping jaw of Fig. 3;

Fig. 5 is a top plan view of a support member; and

Fig. 6 is a perspective view of the support member of Fig. 5. DESCRIPTION OF PREFERRED EMBODIMENT

Figs. 1 and 2 show a vertical cross section and perspective view of a granulator 1 surrounded by protective hoods 2. The granulator 1 has a granulator housing 3 which is also shown in Fig. 2, with side walls 4 and transverse walls 5. The granulator housing 3 has an infeed section 6 into which material to be ground is fed, and a discharge section 7 with a grid 8 through which ground material passes. The grid 8 has holes that correspond to the maximum permitted particle size of the granulate precisely for the intended granulator 1. One of the transverse walls 5 is halved in relation to the side walls 4 in order that the ground material may be removed from the discharge section 7 from beneath.

In the granulator housing 3, a number of stationary knives 9 are disposed, in clamping devices 10, and a rotor 11 with a number of knives 12 is also provided. Each clamping device 10 extends through one of the side walls of the granulator housing, the clamping device 10 displaying operating means 13 disposed on the outside of the granulator housing 3 for clamping and releasing the knife 9 interiorly in the granulator housing 3. The transverse walls 5 have openings 14 in which the rotor 11 is disposed, and also fixing holes 15 for securing bearing housings for the rotor 11. The rotor 11 is rotary by conventional drive means for granulator s.

On grinding of plastic material, the plastic material is fed into the infeed section 6, whereafter the plastic material falls down to the stationary knives 9 and the rotary knives 12. As a result of the cooperation between the knives 9 and 12, the plastic material is ground until it has been comminuted sufficiently to pass down through the grid 8 of the discharge section 7, whereafter the granulate is removed to a receptacle.

The clamping device 10 has a support member 17 fixed in relation to the granulator housing 3 and against which the stationary knife 9 is applied. The clamping device 10 also has a clamping jaw 18 which is movable in relation to the support member 17 for clamping the stationary knife 9 against the support member 17.

Each clamping jaw 18 is disposed in an opening 19 in one of the side walls 4 of the granulator housing 3. The opening 19 is preferably rectangular with side edges 20 and upper and lower edges 21 and 22, respectively. The opening 19 has a dimension that is slightly larger than the clamping j aw 18 at the area of contact of the clamping j aw with the side wall 4, which permits tilting or rocking of the inner end 25 of the clamping jaw 18 up and down on clamping and releasing of the stationary knife 9.

The operating means 13 are disposed to realise urging of the clamping jaw 18 against the support member 17 inside the granulator housing 3, more precisely urging of the outer end portion 23 of the clamping jaw away from the outer end portion 24 of the support member, whereby the clamping jaw 18 will, by cooperation with the opening 19 in the granulator housing 3, obtain a rocking movement, which implies that the inner end 25 of the clamping jaw is urged against the inner end 26 of the support member. During the clamping of the stationary knife 9, the upper side 27 of the clamping jaw 18 is urged against the upper edge 21 of the opening 19.

Figs. 3 and 4 show the clamping jaw 18 which has an edge 28 which prevents unintentional insertion of the clamping jaw 18 too far into the granulator housing 3. The clamping jaw 18 also displays an abutment surface 29 which abuts against the knife 9 in a clamped position. In a view from above, the clamping jaw 18 is in a form similar to a T, the abutment surface 29 being of a length that substantially corresponds to the length of the stationary knife 9, which realises a uniform distribution of the clamping force of the clamping jaw 18 throughout the length of the knife 9. The abutment surface 29 is disposed on a projection 30 on the underside

31 of the clamping jaw, the abutment surface 29 being substantially parallel with the upper side 27 of the clamping jaw.

On its outer end portion 23, the clamping jaw 18 has through holes 32 through which the operating means 13 are disposed. The operating means 13 are preferably clamping screws 33 with lock nuts 34 disposed on the upper side 27 of the clamping jaw, the lock nuts maintaining the clamping screws 33 in their mounted positions during the operation of the granulator 1.

The support member 17 is substantially T-shaped, which is shown in Figs. 5 and 6, and disposed in an opening 35 in the side wall 4 which is shown in Fig. 2. The opening 35 is preferably rectangular, with side edges 36 and upper and lower edges 37 and 38, respectively. The support member 17 has a support surface 39 against which the stationary knife 9 is disposed, and the support surface 39 is of a length which substantially corresponds to the length of the stationary knife 9. The support member 17 further displays guide surfaces 40 which, on mounting, laterally position and guide the support member 17 into the opening 35 in the side wall. The fit of the guide surfaces 40 with the side edges 36 of the opening 35 in the side wall 4 is close, since a large clearance would give rise to undesirable vibration during operation and possibly to an incorrect alignment of the support member.

The support member 17 has abutment edges 41 that abut against the inside 42 of the granulator housing and in which anchorage means are disposed which, from the granulator housing 3, secure the support member 17 on the side wall 4. The anchorage means are screws that are disposed in through holes in the side walls of the granulator housing.

The clamping device 10 has an adjustment device 43 which, from the outside of the granulator housing 3, adjusts the stationary knife 9 towards or away from the knives 12 on the rotor 11. The adjustment device 43 preferably consists of set screws 44 which are disposed in the region between the clamping jaw 18 and the support member 17 flush with the stationary knife 9.

On replacement of the stationary knife 9, the interior of the granulator housing 3 is exposed, whereafter the rotor 11 is set in a favourable position which permits sufficient space in front of the fixed knife 9 in order to make for its removal. Thereafter, the clamping screws 33 on the clamping 'device are backed-off, whereafter the clamping jaw 18 is tilted upwards in order to expose the stationary knife 9. The stationary knife 9 is then worked off, from inside the granulator housing 3, whereafter a new stationary knife is put in position, this also interiorly in the granulator housing 3. Thereafter, the clamping jaw 18 is tilted downwards into abutment against the stationary knife 9, whereafter the clamping screws 33 are tightened. After the clamping of the stationary knife ^'9, it may be adjusted, as is described below.

On adjustment of the stationary knife 9, the interior of the granulator housing 3 is exposed and thereafter the clamping screws 33 on the clamping device 10 are backed-off, whereafter the position of the stationary knife is adjusted by the set screws 44, the distance between the stationary knife 9 and the rotary knives 12 on the rotor 11 being adjusted using, for example, a clearance gauge. When the requisite distance has been measured, the clamping screws 33 are tightened and the protection hoods 2 and covering plates are remounted in position.

Claims

WHAT IS CLAIMED IS:

1. A granulator comprising a granulator housing (3) with a number of stationary knives (9), a rotor (11) which is rotary in the granulator housing (3) and displays a number of knives (12), the granulator housing (3) having an infeed section (6) and a discharge section (7) with a grid (8) through which ground material passes, characterised in that the stationary knives (9) are each disposed in a clamping device (10) which extends through the wall (4) of the granulator housing and which displays on its outside operating means (13) for clamping and releasing the knife (9) interiorly in the granulator housing (3).

2. The granulator as claimed in Claim 1, characterised in that the clamping device (10) includes a support member (17) which is fixed in relation to the granulator housing (3) and against which the stationary knife (9) is disposed, a clamping jaw (18) being movable in relation to the support member (17) for clamping the stationary knife (9) against the support member (17).

3. The granulator as claimed in Claim 1 or 2, characterised in that the operating means are disposed to realise urging of the clamping jaw (18) against the support member (17) inside the granulator housing (3).

4. The granulator as claimed in any of Claims 1 to 3, characterised in that the clamping jaw (18) is disposed in an opening (19) in the granulator housing (3), which has a dimension which permits tilting or rocking of the clamping jaw (18).

5. The granulator as claimed in any of Claims 1 to 4, characterised in that the operating means (13) are disposed to urge the outer end portion (23) of the clamping jaw away from the outer end portion (24) of the support member whereby the clamping jaw (18), by cooperation with the opening (19) in the granulator housing (3), will obtain a tilting or rocking movement, implying that the inner end (25) of the clamping jaw is urged against the inner end (26) of the support member.

6. The granulator as claimed in any of Claims 1 to 5, characterised in that the clamping jaw (18) has an edge (28) which prevents unintentional insertion of the clamping jaw (18) in the granulator housing (3), and an abutment surface (29) which abuts against the knife (9) in a clamped position, of a length that substantially corresponds to the length of the stationary knife (29).

7. The granulator as claimed in any of Claims 1 to 6, characterised in that the clamping jaw (18) has, on its outer end portion (23), through holes (32) through which the operating means (13) are disposed.

8. The granulator as claimed in any of Claims 1 to 7, characterised in that the operating means (13) comprise clamping screws (33).

9. The granulator as claimed in Claim 5, characterised in that the support member (17) is substantially T-shaped and has a support surface (39) against which the stationary knife (9) is disposed, and the support surface (39) is of a length that substantially corresponds to the length of the stationary knife (9).

10. The granulator as claimed in Claim 9, characterised in that the support member (17) has abutment edges (41) which abut against the inside (42) of the granulator housing and in which anchorage means are provided.

11. The granulator as claimed in Claim 2, characterised in that an adjustment device (43) which adjusts the stationary knife (9) towards or away from the knives (12) on the rotor, from the outside of the granulator housing.

12. The granulator as claimed in Claim 11, characterised in that the adjustment device (43) comprises set screws (44).