|Title of Invention||
|Abstract||The present invention relates to a dust separator in a vertical shaft Impactor (VSI). Vertical shaft impactor crushers are used for crushing minerals, stones and hard brittle materials. During crushing process in the VSI, dust is generated, which comes out with the crushed materials from the outlet. This dust sometimes acts as an impurity and is not desirable. Dust while emitting from the outlet creates air pollution. Thus the dust has to be removed. In the present invention the dust is separated from the crushed material in the crushing process itself, utilizing the air pressure generated by the rotor and thus producing dust free crushed material. Further it also utilizes the air stream generated by the rotor. The air stream strikes the crushed material and separates dust. The dust laden air is diverted in upward direction, and to air classifier specially designed to classify and separate the dust from air.|
|Full Text||FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
THE PATENT RULES, 2003
[see section 10 and rule 13]
TITLE OF THE INVENTION
KALANI JUGAL KISHORE KUNJILAL INDIAN
H-2, OLD M.I.D.C. SATARA. 415-004 MAHARASHTRA. (INDIA)
The following Specification particularly describes the invention and the manner in which it is to be performed :-
Title of the invention -
Field of the invention-
The present invention relates to a dust separator in vertical shaft impactor crushers and more particularly to separation of dust by the air pressure generated by the rotor of the VSI which is used to separate the dust from the crushed material which is produced in crushing process and also to diversify the air towards the classifier for further classification and separating the dust of different grades separately. Utilizing the air stream generated by the rotor.
Background of the invention -
The vertical shaft impactors are used to crush minerals, stones or hard brittle materials. The material is crushed due to the collision of stone at vigorous velocity againt each other thus causing the stone or the mineral to be broken into smaller pieces. During this crushing fine dust below 150 microns is also generated and it comes out with the crushed material from the outlet of the VSI crushers. This dust may be upto 7% to 10% of the total crushing. This fine dust must be separated before using the crushed material and also to reduce air pollution while handling the crushed product.
The Vertical shaft Impactor is a more efficient method of crushing the stone and minerals in any required gradation from coarse to fine. While crushing in VSI fine dust is generated. This dust comes out along with the crushed material. The fine dust is undesirable as they may be treated as an impurity and also during process of grading fine dust spreads in atmosphere causing air pollution and occupational hazards. Hence the separation of] the dust from the crushed material is inevitable to prevent all the above problems. Generally water mist is sprayed to suppress the dust at the outlet of the VSI crusher. This helps in reducing the pollution only, but the dust is not separated from the crushed material. Further treatment is required to separate the dust from the crushed material. This dust is Separated by various methods known in the art which is as discussed below.
1. Through sieving or screening'-
The crushed material is separated from the dust by sieving through the vibrating screen, using a fine mesh. The surface area required for sieving is very high to avoid over riding.
The sieve holes get clogged and requires more frequently cleaning of the same. This reduces the efficiency. The screen cloth gets torn/ worn out very fast. For abrasive materials the cloth required to be changed even after every 3-4 Hrs. This increases the maintenance cost. The power consumption is also very high. It also creates sound pollution as the intensity of the sound is more than 60 Db.
2. Air Washing -
Complete crushed product having dust is passed through Air classifier. In this a stream of air is blown perpendicularly towards the flowing material drawing away the fine dust from the crushed product. This requires big air blowers. There is also more wear and tear of the parts. Power consumption is also very high.
3. Water washing -
In this method the crushed product having dust is washed with water over a screw conveyor. The fine dust is washed away by water. This method requires a complete water circulation system. More power is required in this system as whole crushed material is to be washed and handled. There is more wear and tear of the screw conveyor thus increasing the cost of its repairs and maintenance. The water requirement is also very high. If the same water is re-circulated again and again then big settling tanks and filtration plant is required and which occupy a big land.
Thus in all the separating systems known in the art, apart from an additional process, the cost of the running and maintenance is very high. The area required is also very high.
Another lacuna of the VSI crusher is it generates air blow. In some machines it is recirculated to reduce the pollution. This process of re-circulating air, increases the wear of the parts of the machine. This method of re-circulating reduces the pollution but there is wastage of power required to re-circulate the air. Even air classifiers known in the art use blowers to suck the dust or to create negative pressure. The blower fan wears very fast due to dust passing over the fan hence requires replacement every now and then.
Object of the invention-
Thus it is the objective of? the present invention to remove the dust from the crushed material at the source of its generation , so that the crushed material is free from the dust particles.
It is also the objective to simplify the procedure for separation of dust from the crushed material.
It is another objective of the invention to reduce the step of separating the dust from the crushed material.
Furthermore it is also the object to reduce in the extra machinery required for the separation of the dust from the crushed material.
It is also an objective to save the cost of separation of the dust by installation of additional machinery, for its maintenance and repairs .Cost is further saved on power required to run the various separation machines.
It is also the objective to reduce the space required for the purification of the crushed material as it is done within the VSI itself.
It is also the objective to direct the air laden with the dust to the air classifier instead of re-circulation of air within the rotor, thus reducing the wear of the rotor.
The Additional objective is to purify the dust laden air using the positive pressure generated by the rotor itself without application of power or blowers or by creation of negative pressure i.e. vacuum.
Further it is also the objective to separate the dust from the crushed material as well as to further separate the dust of different fineness simultaneously.
It is also an objective to use the classifier as an accessory to the VSI.
It is also the objective to reduce noise pollution while separating the dust from the crushed material.
Further it is also the objective to prevent air pollution by the spread of dust laden air into the surrounding atmosphere and also to prevent occupational hazards because of the dust.
Hence, the present invention purports to achieve all the objectives set above, which will be evident upon perusal of the description of the invention along with the diagrams.
Description of the invention-
The rotor of the Vertical shaft impactor rotates at a high speed to impart energy to the material to be dfushed. The Rotor also acts like a blower and generates heavy blow of air. Obviously some energy is wasted in blowing the air. Generally, this air is recirculated through the rotor to reduce the pollution. The crushed material along with the fine dust exits from the outlet bf the VSI crusher. In this invention the energy wasted in blowing the air is utilized to separate the dust from the crushed material. This air is diversified in upward direction and taken to air Classifier. This reduces the air emission from the out let of the VSI hence reduces the pollution. The crushed product is also free frorri the umjvahted dust.
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Further the diversifiel air is directed in upward direction and is taken to air classifier. This air is laden with thddust particles and by the pressure developed due to the air generated by the rotor is diverted through a pipe into a classifier specially designed for
further separation and collection of the dust particles of different fineness at separate outlets. Thus the air is rendered free from the dust and is shown out after filtration through the bag filters.
Thus the crushed material is freed from the dust and also the dust of varied fineness is separated simultaneously without causing air pollution.
Brief description of the drawings -
Fig, 1 (a) is a cross - sectional schematic view of the VSI showing the procedure for separation of dust from the crushed material.
Fig» 1 (b) is also a cross- sectional schematic view of the VSI showing the direction of dust laden air out through a pipeline to the air classifier, (for smaller models)
Fig 1 (c) is also a cross- sectional schematic view of the VSI showing the direction of dust laden air out through a dome and into pipe to the air classifier where the air generation is more, (bigger models)
Fig 2 shows the schematic construction of the air classifier and the procedure for separation of dust.
Detailed description of the drawings -
Vertical shaft impactor crusher as shown in Fig. 1(A) consists of a vertical shaft (15) which is assembled in bearing housing (2). VSI Body is shown by (1). Rotor is mounted at upper end of the vertical shaft (15).The shaft (15) is driven by belt pulley (16) fitted at the lower end of the shaft. The rotor (3) revolves in a horizontal plane along a vertical axis. The feed material to be crushed enters through the feeding chute (4) through the feed tube (6) and enters into the rotor (3). As the rotor revolves at high RPM the material is thrown away by centrifugal force. The material gains kinetic energy . It strikes on the autogenous ring/ anvil (7) . The material possessing kinetic energy is stopped all of a sudden, due to collision on each other or rock on rock or anvil thus the energy inside the particle blasts it into small pieces. At the same time, the material gets rubbed against each other generating fine dust. When the rotor is revolving at a high speed , it acts as a blower fan and generates High air stream. The air stream is diverted in the upward direction due to autogenous rings. The heavy crushed particles of the material after striking autogenous ring (7) falls down ,and comes out of the VSI crusher from the outlet (8) and is clean from dust.
With the blow of the air generated by the rotor the dust is separated and pushed upwards and taken away by a circular path in the helical annular ring (9) as shown in Fig 1 (B) or through a Dome 9 (1)(C) as shown in Fig. 1(C) and through a pipe (5) to the air classifier. The pipe (5) is inclined at 45 degrees at the horizon and then bent down at the same angle to aid sliding of the dust; downwards without settling in the pipe and thus prevents from clogging . Through piped (5), the air enters the air classifier as shown in Fig 2.
The air classifier shown in fig 2 is specially designed to separate the dust from the air. The whole system is developed on the positive air pressure created by the rotor. The classifier consists of four co- centric cylindrical pipes. The biggest outer circular cylinder (11), a smaller second circular Cylinder (12) which is broad at the top and reducing at the bottom is placed inside circular cylinder (11) within second circular Cylinder (12) is placed a still smaller cylinder (13) which is tapering in shape and gradually reducing in upward direction. A smallest Cylinder (14) which is broad at the top and gradually reducing at the bottom is placed inside cylinder (13). These Cylinders are placed in such a manner that the area of cross section area of air path is gradually increasing . This decreases the velocity of the air. Due to reduction of air velocity the dust particles are unable to cope up and gets separated . A conical vessel (17) is fitted at the bottom of biggest cylinder (11). The coarse dust particles accumulates in this conical vessel and exits through the control valves (19). Similarly, a small conical vessel (18) is fitted at the bottom of taper cylinder (13). This conical vessel no (18) is fitted co centric with conical vessel no (17). The fine dust accumulates in this vessel (18) and exits through out let (20) The biggest cylinder (11) is connected with inlet air pipe (5). The dust laden air from VSI enters classifier through this pipe. The out let pipe (21) is taken out from the smallest Cylinder (14). The air with very fine dust particles in colloidal state is taken to bag filter for filtration.
The dust laden air from VSI enters the air classifier through the cycloid path in downward direction in cylinder (11). Here it takes "U" turn and enters cylinder (12) from the bottom and moves in upward direction. The heavy particles of dust which are unable to take "U" turn are separated from air stream . In cylinder (12) as the cross sectional area gradually increases the air velocity decreases, due to the gravitational force, the particles start descending in the downward direction. Due to decreasing air velocity by increasing the cross sectional area dust particles cannot be air borne for a longer time and settle down. The particles from 75 - 150 microns from cylinders (II) and (12) are collected in the conical vessel (17) and exits through control valve (19). The control valve only lets the dust particles to exit. From cylinder (12) air is again diverted downward direction (complete "IF turn) through cylinder (13) and again takes "u" turn and it enters the central cylinder (14) and flows in upward direction. Again due to reduction in velocity the dust particles fall down and are collected in conical vessel (18) and taken away through control valve (20) The control valves (19) and (20) also prevents the air from passing out. Only fine dust particles are passed out.
The air from central cylinder (14) through outlet pipe (21) goes to the bag filter. This air has dust particles in colloidal states and are filtered in bag filter. Clean air is released in atmosphere.
I CLAIM :-
1. Dust separating system attached along with a vertical shaft Impactor where in the dust is separated from the crushed material and clean crushed material comes out of the VSI simultaneously. The dust is separated ,where it originates by the air pressure which is developed by the rotor due to its high rotating velocity during the crushing of the material. The air laden with the dust is directed through a helical path if the air generated is less or a dome if the air generated is more in upward direction into a specially designed pipe inclined at a particular angle of 45 degrees into a specially designed air classifier which utilizes the positive air pressure and separates the fine dust particles. The dust particles are also separated as per gradation in two sizes and are collected simultaneously.
2. The Separation of dust from crushed material as in claim (1) which is done by the air utilizing the pressurized air blow generated by the rotor.
3. The dust free crushed material as in claim (l)and (2) exits from the outlet at the bottom of the VSI after getting separated from the dust by the air blow generated by the rotor.
4. The air blow as in claim (1) and (2) generated by the rotor, due to its high velocity, which is must to crush the material, further utilized to classify the dust borne air.
5. The direction of the dust laden air as in claim (1) (2) and (4) passed through specific path through upper helical pipe or dome.
6. The utilization of the air blow generated at the rotor as in claim (1) (2) (4) and (5)to divert the air into the classifier.
7. The specially designed air classifier as in claim (1) with co- centric tapering pipes being placed in a co-centric arrangement for changing the path of air in upward and downward direction.
8. The classifier as in claim (1)(2) (4) (6) and (7) being made as an accessory to the VSI. Crushers to utilize the positive pressurized air blow generated by the rotor of the VSI for separating the air.
Any changes and modifications which fall within the sphere of the invention shall be broadly construed to fall within the ambit of the claims.
The present invention relates to a dust separator in a vertical shaft Impactor(VSI). Vertical shaft impactor crushers are used for crushing minerals, stones and hard brittle materials. During crushing process in the VSI, dust is generated, which comes out with the crushed material from the outlet. This dust sometimes acts as an impurity and is not desirable . Dust while emitting from the outlet creates air pollution. Thus the dust has to be removed. In the present invention the dust is separated from the crushed material in the crushing process itself, utilizing the air pressure generated by the rotor and thus producing dust free crushed material. Further it also utilizes the air stream generated by the rotor. The air stream strikes the crushed material and separates dust. The dust laden air is diverted in upward direction, and to air classifier specially designed to classify and separate the dust from air.
|Indian Patent Application Number||913/MUM/2007|
|PG Journal Number||26/2010|
|Date of Filing||15-May-2007|
|Name of Patentee||KALANI JUGAL KISHORE KUNJILAL|
|Applicant Address||H-2, OLD M.I.D.C., SATARA: 415-004|
|PCT International Classification Number||B03B9/00|
|PCT International Application Number||N/A|
|PCT International Filing date|