Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
  • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
  • B02C13/00—Disintegrating by mills having rotary beater elements ; Hammer mills
  • B02C13/26—Details
  • B02C13/286—Feeding or discharge
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
  • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
  • B02C13/00—Disintegrating by mills having rotary beater elements ; Hammer mills
  • B02C13/26—Details
  • B02C13/286—Feeding or discharge
  • B02C2013/28618—Feeding means
  • B02C2013/28663—Feeding means using rollers

Definitions

• Synchroniser and accelerator system for feeding aggregates which coincides with the hammer action to be used with a hammer mill.
• the invention under proposal is a perfected system for feeding aggregate to hammer mills producing sand or other granular material in general, its function being to provide a regulated acceleration of the immission of raw material for processing and the elimination of contact between the hammers and the material to be crushed during those unfavourable moments which give rise to the build-up of unprocessed material in the grinding chamber, thus preventing the optimal use of the hammer surface which are then particularly subject to attrition, above all, at the striking edge.
• the principal effect of the blunting of the striking edges is that after a short period the sand produced no longer conforms to its granulometric standard and the percentage of fine sand to uncrushed or insuffienciently crushed aggregate present is so reduced as to require the urgent replacement of the hammers.
• This invention therefore, consists of ensuring that hammer mills operate in such a way that raw material supply to the hammers is in strictly regulated quantities, delivered in separate batches, and synchronised with the position of the hammers, so as to eliminate the possiblity of raw material being processed positioning itself overwhelmingly at the most distant areas of the hammer face at the moment of impact.
• a suspension in the supply of raw material allowing the material to be worked evenly across the crushing face and not prevalently at the edges.
• the invention consists of ensuring that the material reaches the centre of the hammer and given that it is not possible to increase hammer speed beyond a certain limit, the system under proposal accelerates the falling rate of the raw material within the milling chamber in such a way as to allow it to reach the centre of the working face where it is crushed, thereby reducing the workload of the external surface areas.
• This system brings with it the enormous advantage of minimizing wear to the hammers, with an extension of their operative life five times that of a normal hammer, thereby representing a saving in replacement costs and an elimination of the numerous halts in production which often result.
• a further advantage of the invention under proposal is that its facility for synchronising and accelerating the feeding rate to coincide with the action of the hammers enables a constant, evenly spread impact over much longer production periods, as hammer surface wear affects areas immediately adjacent and parallel to each other; with milling systems lacking this feeder system, however, wear takes place only at the upper striking edge.
• a constantly rectilinear surface area ensures the product always conforms to grain dimension standards and that fine sand is at its correct percentage.
• a steel rectangular box structure containing a roller turned by the rotor of a hammer mill, with transmission supplied by a toothed chain; the two peripheral speeds of roller and rotor, co-ordinated according to the type of hammer mill being used, maintain an average ratio of close to 1 : 10 ; the roller, with scoops evenly spaced over its surface, picks up at fixed intervals the required amount of aggregate; the rate of immission of this material into the milling chamber coincides with a given position of the hammers, more specifically, it is phased with the hammer action in such a way as to ensure that at each strike the area of impact is always situated between the outer edge and the centre of the hammer surface.
• Figure 1 gives an overall view of the raw material feeding system, the invention under proposal, mounted on a hammer mill.
• FIG. 2 shows a cross-section of the device and its internal mechanisms.
• the invention under proposal illustrated in these drawings is composed of a steel box structure forming a rectangular parallelepiped (1) equipped with lid (2) and a window (3) through which the inert material is introduced; within the box structure ( 1 ) is located a roller (4) on the surface of which, placed at regular intervals, four scoops (5) collect the raw material in the correct proportions and deliver it, in acceleration, to the crushing chamber (11) of a two-hammer mill; the roller (4) is rotated by means of a driven pulley (6) moved by the hammer mill rotor through an induction pulley (7) along a transmission belt (8) which is stretched by means of a tension pulley (9).
• the roller's rotating axle (10) protrudes from the box structure ( 1 ) to connect with the driven pulley (6) in such a avay that the end of the two pulleys, driven (6) and induction (7), are perfectly aligned vertically.
• the play of the roller's rotating axle protruding from the. box structure (1) is reduced by a cushioned support which diminishes flexion stress.
• the feeding system is simple to actualise as it requires no materials, processes or any particular operating rules. Moreover, it can be adapted to the majority of hammer mills employed at a tertiary level, being simply mounted by means of bolt fixings at the uppermost point of the hammer mill, and calibrated, with the machinery idle, for a correct setting of the angle of inclination of the scoops situated on the roller (4).

Landscapes

• Engineering & Computer Science (AREA)
• Food Science & Technology (AREA)
• Crushing And Pulverization Processes (AREA)
• Crushing And Grinding (AREA)
• Chutes (AREA)
• Percussive Tools And Related Accessories (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=11407479

Family Applications (1)

Country Status (9)

Cited By (3)

Families Citing this family (4)

Citations (3)

• 1994
  • 1994-09-30 IT IT94SA000008A patent/IT1281944B1/it active IP Right Grant
• 1995
  • 1995-09-13 WO PCT/IT1995/000149 patent/WO1996010457A1/en active IP Right Grant
  • 1995-09-13 JP JP8511583A patent/JPH10511886A/ja active Pending
  • 1995-09-13 CA CA002201109A patent/CA2201109A1/en not_active Abandoned
  • 1995-09-13 AU AU35769/95A patent/AU3576995A/en not_active Abandoned
  • 1995-09-13 DE DE69510072T patent/DE69510072D1/de not_active Expired - Lifetime
  • 1995-09-13 EP EP95932899A patent/EP0783373B1/en not_active Expired - Lifetime
  • 1995-09-13 AT AT95932899T patent/ATE180690T1/de active
  • 1995-09-13 CN CN95195409.1A patent/CN1159772A/zh active Pending

Patent Citations (3)

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