CN1297349C

CN1297349C - Preumatic mill

Info

Publication number: CN1297349C
Application number: CNB031164854A
Authority: CN
Inventors: 戴德林; 王育平; 路河树; 张书来; 金小兵; 陈俊民
Original assignee: Ningbo Yunsheng Group Co Ltd
Current assignee: Ningbo Yunsheng Group Co Ltd
Priority date: 2003-04-18
Filing date: 2003-04-18
Publication date: 2007-01-31
Anticipated expiration: 2023-04-18
Also published as: CN1443606A

Abstract

The present invention relates to a gas stream grinder which successively comprises an air compressor, a grinding chamber and a cyclone separator according to the flow direction of gas streams. The gas stream grinder is characterized in that a rough powder separator is connected in series between the grinding chamber and the cyclone separator, the lower part of the rough powder separator is provided with a material returning port communicated with the grinding chamber, the middle part of the rough powder separator is provided with a material inlet port communicated with a material discharge port of the grinding chamber, and a material discharge port of the top part of the rough powder separator is communicated with a material inlet port of the cyclone separator. The top part of the rough powder separator can be provided with a cone separator or a separating wheel so as to control the grain size of a powder body and improve the pattern of grains. The good separating wheel is in a dense stripe shape or a meshed shape having a peripheral wall with multiple holes, and the good rotating speed of the separating wheel is 3000 to 10000 circle/min so as to further control the grain size of the powder body. Preferably, the inner wall of a shell body below the cone separator or the separating wheel is provided with an inclined lower stream stopping plate so as to block and prevent rough grains from entering the cone separator or the separating wheel, and therefore, the grain size of the powder body is preferably controlled. The gas stream grinder efficiently lowers the proportion of large grains in discharged material, the largest grain can be lowered to below 15 microns, and the grain size of the powder material of a finished product is uniform.

Description

A kind of airflow milling

Technical field

The present invention relates to a kind of injection class size reduction machinery, particularly a kind of fluidized bed jet mill.

Background technology

Airflow milling is a kind of disintegrating apparatus that utilizes air-flow material to be pulverized, is processed into the micron order micro mist, its operation principle is that gases at high pressure are accelerated into high velocity air by nozzle, make the indoor material particles impact mutually of mill, collision friction and pulverize, air-flow also drives pulverized particles and enters graded region and carry out after the classification outside the discharge machine simultaneously.At present, airflow milling is by industrial and mining enterprises' extensive use, particularly be applied to the powder metallurgy industry, as neodymium iron boron (NdFeB) magnetic material manufacturing industry, the general closed loop airflow milling that adopts, its structure and operation principle are: air compressor compression work gas (inert gas, nitrogen etc.) inject the mill chamber at a high speed by nozzle, collision mutually takes place in the mill chamber and pulverizes in material, then by being arranged on the high speed rotation grading wheel control product granularity of mill chamber tip position, wherein pulverized material enters cyclone separator and goes out the finished product powder from the discharging opening of cyclone separator from the discharging opening of mill chamber, and the material that is not crushed to finished product as yet returns the indoor continuation pulverizing of mill again, the air-flow that comes out from cyclone separator purifies through filter then, return the air compressor compression, operation with closed ring.Yet the powder that utilizes existing homemade airflow milling to process still exists following defective: the one, and granularity is still bigger, still has many 25 microns coarse granules; The 2nd, size distribution and particle size uniformity are good inadequately; The 3rd, the granularity pattern is poor, mostly is pointed shape; The 4th, have the oxidized phenomenon of finished product, and powder is thin more, oxidative phenomena is serious more, becomes implacable contradiction.And these have crucial influence for every performance of neodymium iron boron (NdFeB) magnetic material.

Summary of the invention

First technical problem to be solved by this invention is to provide a kind of can make the further airflow milling that reduces of the powder particles that processes at above-mentioned prior art present situation.

Second technical problem to be solved by this invention provides a kind of airflow milling that can process the comparatively uniform powder of granularity.

The 3rd technical problem to be solved by this invention provides a kind of airflow milling that can make the powder that processes have better pattern.

The 4th technical problem to be solved by this invention provides a kind of airflow milling that can effectively reduce the powder oxidative phenomena and further improve the powder fineness.

The present invention solves the problems of the technologies described above the technical scheme that is adopted: this airflow milling includes air compressor, mill chamber and cyclone separator successively by the flow direction of air-flow, it is characterized in that also being serially connected with between described mill chamber and cyclone separator a mill separator: its underpart has a feedback outlet and is connected with the mill chamber, the middle part has a charging aperture and is connected with the discharging opening of mill chamber, the discharging opening at its top then is connected with the charging aperture of cyclone separator, and this mill separator also is provided with cone separator or separation wheel at its tip position.

It is good that described separation wheel is holey with close stripe-shaped or perisporium, and its rotating speed is good with 3000～10000 rev/mins, with the granularity of further control powder; Better, the inner walls under described cone separator or the separation wheel is provided with oblique intercepter plate down, enters cone separator or separation wheel to stop, to hold back coarse granule, thereby controls the granularity of powder better;

Described mill chamber height is good with 700～1000mm, and it is good that the separation wheel that is installed in its tip position is holey with close stripe-shaped or perisporium, and rotating speed is good with 2000～5000 rev/mins, with the granularity of control discharging powder; Better, at the nozzle place, the end of described mill chamber one pressure regulator valve can also be installed;

In order to prevent the powder oxidation, can also between air compressor and mill chamber, set up a refrigeration machine, spurt into the temperature of the working gas of mill chamber by reduction, reduce oxidative phenomena effectively;

For the powder granularity that further guarantees discharging meets the requirements fully, also can set up a sieving machine, to screen out the coarse granule that wherein may sneak at the discharging opening place of cyclone separator.

Compared with prior art, the mill separator of the present invention by setting up between mill chamber and cyclone separator reduced oarse-grained ratio in the discharging effectively, and the largest particles can be reduced to below 15 microns; And by shape separator or separation wheel are set at mill separator, make that powder granularity is satisfactory can enter cyclone separator that the undesirable powder of granularity then is blocked and sends back to the mill chamber and refaces by cone separator or separation wheel; Thereby make the granularity of finished product powder more even.In addition, practice shows that mill chamber height is selected 700～1000mm, and coarse granule is difficult for entering in the separation wheel, adds the adjusting of end nozzle valve, makes the grain graininess that enters separation wheel be controlled in the scope of requirement, has improved the pattern of particle simultaneously; Moreover the present invention adopts refrigeration machine, and control also reduces the temperature that enters mill office work gas, thereby the temperature of control mill chamber is avoided the generation of fine powder body oxidation.

Description of drawings

Fig. 1 is the structural representation of the embodiment of the invention.

Fig. 2 is the structural representation of mill separator among Fig. 1.

Fig. 3 is the structural representation of another kind of mill separator.

Fig. 4 is the structural representation of mill chamber among Fig. 1.

The close stripe-shaped separation wheel structural representation of Fig. 5 for adopting in mill separator or the mill chamber.

The holey type separation wheel structural representation of Fig. 6 for adopting in mill separator or the mill chamber.

The specific embodiment

Embodiment describes in further detail the present invention below in conjunction with accompanying drawing.

As Fig. 1～shown in Figure 6, be the embodiment of closed loop airflow milling; The flow direction by air-flow includes air compressor 1, refrigeration machine 2, mill chamber 3, mill separator 4, cyclone separator 5 and filter 6 successively, referring to Fig. 1;

Wherein the bottom of mill separator 4 has a feedback outlet 43 and is connected with the feedback outlet 32 of mill chamber 3, and the middle part has a charging aperture 42 and is connected with the discharging opening 31 that

grinds chamber

3, and 41 of the discharging openings at its top are connected with the charging aperture 51 of cyclone separator 5, referring to Fig. 2; This mill separator 4 is provided with cone separator 44 at its tip position, with the granularity of control powder, improve the pattern of particle, powder granularity is satisfactory can to enter cyclone separator 5 by cone separator 44, the undesirable powder of granularity is blocked, and goes back to mill chamber 3 and refaces;

Described cone separator 44 also can be replaced so that separation wheel 45 to be arranged, referring to Fig. 3; Described separation wheel 45 selects for use close stripe-shaped (referring to Fig. 5, stitch the wide 2～6mm of being, the seam centre-to-centre spacing be 3～10mm) or perisporium be holey (referring to Fig. 6, the aperture is that 1～3mm, hole centre-to-centre spacing are 2～10mm), and its rotating speed is 3000～10000 rev/mins, with the granularity of further control powder; In mill separator shown in Figure 34, on the inner walls under the described separation wheel 45, also be provided with oblique intercepter plate 46 down, enter cone separator 44 or separation wheel 45 to stop, to hold back coarse granule, thereby control the granularity of powder better;

As shown in Figure 4, described mill chamber 3 height are good with 700～1000mm, draw from test repeatedly: mill chamber height stream condition in this scope can change, and coarse granule is difficult for being blown in the separation wheel 34 that is arranged on its tip position; And described separation wheel 34 selects for use close stripe-shaped (referring to Fig. 5, stitch the wide 2～6mm of being, the seam centre-to-centre spacing be 3～10mm) or perisporium in holey (referring to Fig. 6, the aperture is that 1～3mm, hole centre-to-centre spacing are 2～10mm), and rotating speed is 2000～5000 rev/mins, with the granularity of control discharging powder; And, at the nozzle place, the end of described mill chamber one pressure regulator valve 33 can also be installed, make the grain graininess that enters separation wheel 34 be controlled in the scope of requirement;

Be arranged on air compressor 1 and the refrigeration machine 2 of mill between the chamber 3 and can control and reduce the temperature that enters working gas in the mill chamber 3, thereby the temperature of control mill chamber 3 is avoided the generation of fine powder body oxidation;

Discharging opening 52 places at cyclone separator 5 also are provided with a sieving machine 7, to screen out the coarse granule that wherein may sneak into.

Claims

1, a kind of airflow milling, the flow direction by air-flow includes air compressor, mill chamber and cyclone separator successively, it is characterized in that also being serially connected with between described mill chamber and cyclone separator a mill separator: its underpart has a feedback outlet and is connected with the mill chamber, the middle part has a charging aperture and is connected with the discharging opening of mill chamber, the discharging opening at its top then is connected with the charging aperture of cyclone separator, and this mill separator also is provided with cone separator or separation wheel at its tip position.

2, airflow milling according to claim 1, the rotating speed that it is characterized in that described separation wheel is 3000～10000 rev/mins.

3, airflow milling according to claim 2 is characterized in that described separation wheel is close stripe-shaped, and its seam is wide to be 2～6mm, and seam centre-to-centre spacing is 3～10mm.

4, airflow milling according to claim 2 is characterized in that its perisporium of described separation wheel is holey, and its aperture is 1～3mm, and hole centre-to-centre spacing is 2～10mm.

5,, it is characterized in that the inner walls under described cone separator or the separation wheel is provided with oblique intercepter plate down according to the described airflow milling of arbitrary claim in the claim 1 to 4.

6,, it is characterized in that described mill chamber height is 700～1000mm according to the described airflow milling of arbitrary claim in the claim 1 to 4.

7, airflow milling according to claim 6 is characterized in that described mill chamber is equipped with a pressure regulator valve at its nozzle place, end.

8, airflow milling according to claim 7 is characterized in that the separation wheel rotating speed of its tip position of described mill chamber is 2000～5000 rev/mins.

9, airflow milling according to claim 8 is characterized in that described separation wheel is close stripe-shaped, and its seam is wide to be 2～6mm, and seam centre-to-centre spacing is 3～10mm.

10, airflow milling according to claim 8 is characterized in that its perisporium of described separation wheel is holey, and its aperture is 1～3mm, and hole centre-to-centre spacing is 2～10mm.

11,, it is characterized in that between air compressor and mill chamber, also being provided with a refrigeration machine according to the described airflow milling of arbitrary claim in the claim 1 to 4.

12,, it is characterized in that also being provided with a sieving machine at the discharging opening place of described cyclone separator according to the described airflow milling of arbitrary claim in the claim 1 to 4.