Claims:We Claim,

1. A system for separating fine particles from quarry dust/crushed sand, wherein the fine particles in the range of 150 micron to 2.36mm, 150 micron to 4.75mm are separated and dust below 150 micron is removed from the quarry dust/crushed sand, comprising:

a rotating drum (41) having an inlet (43) for receiving aggregates from one end and a means for blowing counter flow air from opposite end inside the drum (41);

a pre-separator (5) having plurality of stacked, spaced apart slanted plates (51), said pre-separator (5) being connected with drum (41) through a bent exhaust duct (11), the plates (51) allowing particles to strike on and enabling the particles of 100micron to 1mm to collect at the bottom of the pre-separator (5);

a cyclone separator (6) being connected to the pre-separator (5), said cyclone separator (6) separate particles of size in the range of 50-150 micron;

a bag house filter (7) being connected to the cyclone separator (6) through a bent exhaust duct (12) and having plurality of bags wherein the fine particles below 50 microns are trapped and falls below by reverse air flow /pulsejet cleaning system at regular intervals;

characterized in that, said drum (41) is composed of two zones namely a dust collecting zone (401) located downstream to the material inlet (43) and a rotary screening zone (402) located downstream to the dust collecting zone (401).

2. The system for separating fine particles from quarry dust/crushed sand as claimed in claim 1, wherein in screening zone (402), said drum (41) comprises a first rotary screen (402a) located adjacent to the dust collecting zone (401) and a second rotary screen (402b) located adjacent to the first screen (402a).

3. The system for separating fine particles from quarry dust/crushed sand as claimed in claim 1, wherein said drum (41) is provided with a plurality of lifting flight (401a) along the internal wall of the drum (41) which lifts and showers the material inside full section of the drum (41).

4. The system for separating fine particles from quarry dust/crushed sand as claimed in claim 3, wherein said first screen (402a) filters and discharge the particles of 150 micron to 2.36 mm and the second rotary screen (402b) filter and discharge the particles of 2.36mm to 4.75 mm.

5. The system for separating fine particles from quarry dust/crushed sand as claimed in claim 1, wherein Y-chutes (Y1, Y2) with flapper are provided below said first rotary screen (402a) and said second rotary screen (402b).

6. The system for separating fine particles from quarry dust/crushed sand as claimed in claim 1, wherein said drum (41) is equipped with drum inclination setting device for adjusting the inclined position of the drum (41).

7. The system for separating fine particles from quarry dust/crushed sand as claimed in claim 1, wherein the optimum velocity of air being blown inside the drum (41) through the blower is preferably kept in the range of 2-2.4 m/s.

8. The system for separating fine particles from quarry dust/crushed sand as claimed in claim 1, wherein said drum (41) is positioned angularly relative to the horizontal axis so that the material is gravitationally conveyed from the inlet (43) towards the rotary screen zone (402).

9. The system of separating fine particles from quarry dust/crushed sand as claimed in claim 1, wherein the drum (41) is positioned in an inclination at the angle in the range of 50 to 60.

10. A method for separating fine particles from quarry dust/crushed sand comprising a steps of:

a. adjusting the inclination position of the drum (41) at an angle in the range of 50 to 60 ;
b. feeding material (quarry dust/crushed sand) inside the drum (41) from inlet (43);
c. blowing air with velocity in the range of 2-2.4 m/s inside the drum (41) from opposite end thereof;
d. showering material inside the drum (41) through the rotation of the drum (41);
e. discharging the fine particles of 150 micron to 2.36mm from the first screen (402a);
f. discharging the fine particles of 2.36mm to 4.75mm from the second screen (402b);
g. mixing the required material in the range of 150 micron to 2.36mm and 2.36mm to 4.75mm to obtain the material in the range of 150 micron to 4.75mm;
h. carrying dust laden air into the pre-separator (5) from the drum (41) through the bent exhaust dust (11);
i. allowing blown dust to strike on a plurality of plates (51) and collecting the particles of 100micron to 1mm from the bottom of the pre-separator (5);
j. passing the dust laden air into the cyclone separator (6);
k. creating centrifugal force on the particles causing the particles of 50 micron to 150 micron to collect at the bottom of the cyclone separator (6);
l. carrying the dust laden air into the bag house filter (7);
m. trapping the particles of below 50 micron inside the bags and collecting the trapped particles from the bottom of the bag house filter (7);
n. sucking and discharging residue clear air from the bag house filter (7) to atmosphere.

Dated this on 20th March, 2018.
, Description:

FORM 2
THE PATENT ACT 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)
1. TITLE OF THE INVENTION: A System for Separating Sand Particles from Quarry Dust/Crushed Sand and Method thereof

2. APPLICANT:
(a) NAME : MAXMECH EQUIPMENTS PVT. LTD.
(b) NATIONALITY : An Indian
(c) ADDRESS : 410, Iscon Elegance,
Nr. Prahalad Nagar, S.G. Highway,
Ahmedabad - 380 015,
Gujarat, India.

PREMABLE TO THE DESCRIPTION

PROVISIONAL

The following specification describes the invention.
þ COMPLETE

The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF THE INVENTION

The present invention relates to a system and method for treating the dust particles and more particularly it relates to a system and method for separating fine aggregates particles in the range of 150 micron to 2.36mm, 150micron to 4.75mm and for removing dust below 150 micron from quarry dust as well as from crushed sand.

BACKGROUND OF THE INVENTION

Sand mining on either side of the rivers, upstream or in-stream is one of the causes for environmental degradation and also a threat to the biodiversity. Over the alarming rate of unrestricted sand mining which damage the ecosystem of natural habitats of organisms living on the riverbeds, affects fish breeding and migration, spells disaster for the conservation of many bird species, increases saline water in the rivers, etc. The demand for sand continues to increase day by day as building and construction of new infrastructures and expansion of existing ones is continuous thereby placing immense pressure on the supply of the sand resource and hence mining activities are going on legally and illegally without any restrictions. Lack of proper planning and sand management cause disturbance of marine ecosystem and also upset the ability of natural marine processes to replenish the sand. In this situation, the construction industries of developing countries are in stress to identify alternative materials to lessen or eliminate the demand for natural sand. So, quarry waste/crushed sand fine aggregate could be an alternative of natural sand. It is a byproduct generated from quarrying activities involved in the production of crushed coarse aggregates. Quarry waste fine aggregate, which is generally considered as a waste material after the extraction and processing of rocks to form fine particles less than 4.75mm, causes an environmental load due to disposal problem. Hence, the use of quarry waste fine aggregate in concrete mixtures will reduce not only the demand for natural sand but also the environmental burden. Moreover, the incorporation of quarry waste fine aggregate will offset the production cost of concrete. In brief, the successful utilization of quarry waste fine aggregate will turn this waste material into a valuable resource.

The enormous amount of quarry dust/crushed sand is produced during the working of crusher plant and vertical shaft impactor (VSI). In VSI and crusher plant, during crushing of stones, lots of quarry dust is produced which is rarely used and it occupies big space of the useful land in quarry premises for storage purpose. For optimum utilization of said quarry dust, various kinds of systems have been developed heretofore for extracting the fine sand particles from the quarry dust.

In one typical method, the fine aggregates crushed from Vertical Shaft Impactor (VSI) are passed over a screen to separate material of different sizes. This process is also known as gradation of the aggregate. For gradation, different types of screens are used, such as rotary screens, vibrating screens etc. However, said system is appropriate for segregations of large particles and is not accurate and fails to separate fine particles size below 150 micron.

OBJECT OF THE INVENTION

The main object of present invention is to provide a system and method for separating fine particles from quarry dust/crushed sand that overcomes the problems associated with conventional dust removing systems.

Another object of present invention is to provide a system and method for separating fine particles from quarry dust/crushed sand that effectively remove the dust below 150micron and separate fine particles in the range of 150 micron to 2.36mm and 150micron to 4.75mm from the quarry dust/crushed sand.

Further object of the present invention is to provide a system that provides a pollution-free solution by trapping the dust particles from the quarry dust/crushed sand.

SUMMARY OF THE INVENTION

The present invention discloses a system for separating fine particles of various sizes from quarry dust/crushed sand. Said system mainly comprising a drum assembly wherein particles in the range of 150 micron to 2.36mm and 2.36mm to 4.75mm are separated from the quarry dust/crushed sand, a pre-separator having plurality of flappers, said pre-separator being connected with drum assembly, the flappers allowing particles to strike on and enabling the particles of 100micron to 1mm to collect at the bottom of the pre-separator, a cyclone separator being connected to the pre-separator that separate particles of size in the range of 50-150 micron, a bag house filter being connected to the cyclone separator and having plurality of bags wherein the fine particles below 50 microns are trapped and falls below by an automatic cleaning device at regular intervals.

According to present invention, said rotating drum assembly comprises a rotating drum being mounted on a chassis in decline position and having an inlet for receiving quarry dust/crushed sand and a blower for blowing counter flow air with respect to inlet of material inside the drum. Said drum is composed of mainly two zones namely a dust collecting zone located downstream to the material inlet and a rotary screening zone located downstream to the dust collecting zone. Said rotary screens separate the fine particles in range of 150 micron to 2.36mm and 2.36mm to 4.75mm. Further, in dust collecting zone, a plurality of lifting flights is provided along the internal wall of the drum which lifts and showers the material inside full section of the drum. During showering, heavy particles of 150 micron to 4.75mm fall down due to gravitation and small particles below 150 micron blown and exhausted into the pre-separator, cyclone separator and bag house filter successively. Thus, all fine particles from the dust are separated and clear air is left into the atmosphere.

BRIEF DESCRIPTION OF THE DRAWINGS`
Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the present embodiment when taken in conjunction with the accompanying drawings.
Fig. 1 illustrates a schematic view of the system for separating fine particles from quarry dust/crushed sand according to present invention.

Fig. 2 illustrates a perspective view of the system for separating fine particles from quarry dust/crushed sand according to present invention.

Fig. 3 illustrates a perspective view of the rotating drum assembly according to present invention.

Fig. 4 illustrates an inside view of the drum assembly according to the present invention.

Fig. 5 illustrates a perspective view of the showering process carried out in the drum.

Fig. 6 illustrates a perspective view of the cyclone separator and pre-separator in combination according to present invention.

Fig. 7 illustrates a perspective view of the reverse air flow bag house filter according to present invention.

Fig. 8 illustrates a perspective view of the pulsejet bag house filter according to present invention.

DETAILED DESCRIPTION OF THE INVENTION

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of the construction and arrangement of parts illustrated in the accompanied drawings. The invention is capable of other embodiments, as depicted in different figures as described above and of being practiced or carried out in a variety of ways. It is to be understood that the phraseology and terminology employed herein is for the purpose of description and not of limitation.

Fig. 1 and Fig. 2 illustrate a system for separating fine particles of from quarry dust/crushed sand. Further, the present invention separate fine particles of different size from the aggregate i.e. 150 micron to 2.36 micron, 150 micron to 4.75mm and also remove dust particle below 150 micron. In system according to present invention, quarry dust/crushed sand is fed at one end of the system and clean sand particles in the range of 150 micron to 4.75mm is collected at other end. Further, in this system, the dust below 150 micron is also trapped so that environment friendly air particles are released into the atmosphere.

In accordance with embodiment of the present invention, as shown in Fig. 1 and Fig. 2, said system mainly comprises a material feeding hopper (1), a vibro feeder (2) located below the material feeding hopper (1), a feeding belt conveyor (3) that receives material from the bottom of the vibro feeder (2) and conveying the material from the feeding hopper (2) towards a drum assembly (4), a rotating drum assembly (4), a pre-separator (5) being connected with a drum assembly (4) through a bent exhaust pipe (11), a cyclone separator (6) being connected with the pre-separator (5), a bag house filter (7) being connected with cyclone separator (6) through a bent exhaust pipe (12), a common screw conveyor (8) being passed from the bottom of the pre-separator (5), the cyclone separator (6) and the bag house filter (7) for receiving discharged fine particles, an exhaust blower (9) and an insulated control panel (10) for controlling the entire operation of the system.

Said material feeding hopper (1) wherein the quarry dust/crushed sand stored is provided with vibration motor mounted at its discharge end. Further, said material feeding hopper (1) is provided with suitable ramp for continuous dumping of quarry dust/crushed sand. From the bottom of this hopper (1), material is fed to the Vibro Feeder (2) which removes the over size material and discharge the remaining material to feeding belt conveyer (3) by gravity. A flow regulating device is fitted below this hopper (1) to regulate the flow as per requirement. A weigh bridge with electronic load cell is fitted in this conveyor (3) which indicates TPH flow of input material, the same is also displayed in the panel (10). Said TPH flow is set by the regulating device.

Now as shown in Fig. 3 and Fig. 4, said rotating drum assembly (4) comprises a rotating drum (41) preferably made from, but not limited to, heavy duty steel, said rotating drum (41) is mounted on a chassis (42) in declined position and having a material inlet (43) through which material is introduced therein, an outlet (44) for exhausting small dust particles to the pre-separator (5) through said bent exhausting duct (11) (shown in Fig. 2), a friction drive (not shown) for smooth rotation of the drum (41) and a drum inclination setting device (not shown) for adjusting the inclined position of the drum (41).

The detailed configuration of the drum (41) is shown in the Fig. 4. According to Fig. 4, the drum (41) is composed of mainly two zones namely a dust collecting zone (401) located downstream to the material inlet (43) and a rotary screening zone (402) located downstream to the dust collecting zone (401). Said dust collecting zone (401) is provided with a plurality of lifting flights (401a) along the internal wall of the drum (41) which lifts and showers the material inside full section of the drum (41) as shown in Fig. 5. In screening zone (402), the drum (41) is provided with a first rotary screen (402a) located adjacent to the dust collecting zone (401) and a second rotary screen (402b) located adjacent to the first screen (402a). The first screen (402a) allows the particles size in the range 150 micron to 2.36 mm to filter and discharge onto a Y-chute (Y1) provided with flapper gate located below said screen (402a). Said second rotary screen (402b) allows the particles size in the range of 2.36mm to 4.75 mm to filter and discharge onto a Y-chute (Y2) provided with flapper gate located below said screen (402b).
Referring continuous with Fig. 4, due to said flapper gates in Y-chute (Y1) and Y-chute (Y2), required proportion of the material of 150micron to 2.36mm and 2.36mm to 4.75mm is diverted and mixed so that fine material of 150 micron to 4.75mm is obtained as per customer requirement. Then, said fine material in the range of 150micron to 4.75mm is conveyed through a conveyor (C2) into a vertical square duct (D2). Further, the remaining proportion of said discharged material of 150 micron to 2.36mm is conveyed through a belt conveyor (C1) into a vertical square duct (D1). Further, said drum (4) is also provided with discharge chute (403) located downstream to the second screen (402b) for discharging the large particles size above 4.75mm onto a belt conveyor (C3) that convey said material into the vertical square duct (D3).

Said vertical square duct (D1, D2, D3) has a hinged type opening on all sides at regular interval, so that no dust is emitted in the atmosphere and it falls smoothly on the ground making a natural heap. Thus, the smooth stock pile of sand is formed.

Further, at another end of the system, a blower (not shown) is mounted that introduce the air with optimum velocity within the drum (41) (shown by Arrow A). Thus, the material flow and air flow are counter flow. Further, said drum (41) is also equipped with fipple (not shown) that evenly distributes the air inside the drum (41) being blown from the blower. Further, said drum (41) is positioned angularly relative to the horizontal axis so that the material is gravitationally conveyed from the inlet (43) towards the discharge (403).

As shown in Fig. 6, Said pre-separator (5) comprises a plurality of stacked, spaced apart slanted plates (51) that allow particles of the aggregates to strike on and pass through selectively depending upon the size of the particles. Said plates (51) are mounted in angular position so that momentum of dust particles coming from the drum (41) is disturb whereby heavy particles of 100micron to 1 mm is arrested in pre-separator (5) and collected at bottom. The collected particles are discharged from the rotary air lock valve (53) to the common screw conveyer (8) located below said pre-separator (5).

Referring continuous with Fig. 6, Said cyclone separator (6) comprises a conical hollow space wherein high speed rotating air flow is established, an exhaust (61) formed on the top of the cyclone separator (6) and a rotary air lock valve (62) located at bottom of the cylindrical separator (6) for discharging separated fine particles onto the screw conveyer (8).

As shown in Fig. 7, said bag house filter (7) having an duct inlet (71) being connected with the exhaust (61) of the cyclone separator (6) through said bent exhaust duct (12) comprises a plurality of bags wherein the very small fine particles are trapped and falls below by an automatic cleaning device at regular intervals. Further, 3 sets of reverse air flow bag cleaning apparatus (72) is provided on the top of the bag house (7) which is operated by an electric motor. Hence, all the bags are cleaned continuously step by step in rows during the suction.
According to another embodiment, said bag house filter may be a pulsejet system bag house wherein small particles are effectively trapped as shown in Fig. 8.

The working of aforesaid system is described below in detail. First, the raw material (herein quarry dust/crushed sand) is collected in the storage hopper (1). From the bottom of this hopper (1), material is fed into the vibro feeder (2) wherein the oversize material is captured and the remaining material is fed into the belt conveyor (3) by gravity. Said flow regulating device regulates said flow of material being discharged from the vibro feeder (2). Then, said material is conveyed toward the inlet (43) of the drum (41) through the conveyor belt (3). Through said inlet (43), the material is fed into the rotating drum (41). At the same time, air is blown into the drum (41) from opposite end via the blower with optimum velocity preferably in the range of 2-2.4 m/s. Due to fipple, the air flow is uniformly distributed within the drum (41). First, the material is introduced within the dust collecting zone (401). Further, due to continuous rotation of the drum (41), the material is showered with help of lifting flights (401a) inside the drum (41). Due to declined position of the drum (41), the showered material slide towards the rotary screen zone (402). In this zone, the particles in the range of 150 micron to 2.36mm are filtered through the first screen (402a) and discharged onto a belt conveyor (C1) through the Y-chute (Y1). The material above 2.36mm is slide over the second screen (402b) that filters and discharges all particles in the range of 2.36mm to 4.75mm through the Y-chute (Y2). The remaining particles above 4.75mm are discharged through the discharge opening (403) onto the conveyor (C3). Here, the flapper gate of Y-chute (Y1) diverts required proportion of the particles in the range of 150 micron to 2.36mm and flapper gate of Y-chute (Y2) diverts required proportion of the material in the range of 2.36mm to 4.75mm. Thus, said material in the range of 150 micron to 2.36mm and material in the range of 2.36mm to 4.75mm are mixed so that the material of fine particles in the range of 150micron to 4.75 is obtained which is conveyed by said conveyor (C2) into the vertical duct (D2).

Said belt conveyor (C1, C2 and C3) conveys said material to the stockpile. During showering of materials, the dust laden air with fine particles (size below 150 micron) move along with blown air from the drum (41) and enter into the pre-separator unit (5) through the bent pipe (11) from the exhaust (44) (direction of dust air being entered into and exhausted from the pre-separator is indicated by arrow A as shown in Fig. 6).

In pre-separator (5), the particles coming from bent pipe (11) are strike on the plates (51) so that the momentum of dust particles is disturbed. Here, due to loss of momentum, heavy particles of 100micron to 1mm fall into bottom of the pre-separator (5) and are taken out through the rotary valve (53) (shown in Fig. 6). The smaller particles of size below 150 micron which are not trapped by the pre-separator (5) are carried forward along with dust laden air into the cyclone separator (6) through a passage (52). In cyclone separator (6), high speed rotating air flow is established within the conical container (6). Here, air flow in a helical pattern, beginning at the top of the cyclone (6) and ending at the bottom end before exiting in the cyclone in a straight stream through the centre of the cyclone and out the top. Larger (denser) particles of size in the range of 50-150 micron in the rotating stream have too much inertia to follow the tight curve of the stream, and strike the internal wall of the cyclone (6) and then fall to the bottom of the cyclone wherefrom said particles are collected and fall onto the common screw conveyor (8) through the rotary valve (62). Thus, in cyclone dust collector (6), all fines particles of 50-150 micron are collected. In order to trap the particles below 50 micron, the dust with particles below size of 50 micron is carried into the bag house filter (7) through the bent duct (12) by the duct inlet (71). Here, all the fine particles of below 50 micron are trapped inside these bags and falls below by a special automatic cleaning device at regular intervals onto said common conveyor belt (8). The bags are cleaned continuously step by step by said reverse air flow (72)/pulse jet bag cleaning system (direction of dust air being entered into and exhausted from the bag house filter is indicated by arrow B as shown in Fig. 7). Here, after separation of particles from the dust, a clean fresh air is remained as the residue which is left through the duct outlet (73) from the bag filter house (7) and exhausted into the atmosphere by the exhaust blower (9). Thus, the clean sand of different particle size is produced separately.

The present invention is experimented and illustrated more in details in the following example. The example describes and demonstrates embodiments within the scope of the present invention. This example is given solely for the purpose of illustration and is not to be construed as limitations of the present invention, as many variations thereof are possible without departing from spirit and scope.

Example:

The experiment was carried out by feeding the 60 tons/hour quarry dust into the drum. The speed of rotation of drum was kept 10 R.P.M. The 40 to 60. The reading was taken at velocity of air being blown into the drum at 1.6m/s, 2 m/s and 2.2m/s. The achieved results are shown in below table.

Sr. No. Velocity of Air inside Drum (in m/s) Declination of Drum Amount of dust (below 150 micron) in production (in %)
1. 1.6 40 15%
2. 1.6 50 13%
3. 1.6 60 15%
4. 2 40 10%
5. 2 50 8%
6. 2 60 12%
7. 2.4 40 6%
8. 2.4 50 4%
9. 2.4 60 9%

From aforesaid result, it is seen that when the declination of drum is kept 50 to 60, the optimum result is achieved at different-different velocity of air.

The invention has been explained in relation to specific embodiment. It is inferred that the foregoing description is only illustrative of the present invention and it is not intended that the invention be limited or restrictive thereto. Many other specific embodiments of the present invention will be apparent to one skilled in the art from the foregoing disclosure. All substitution, alterations and modification of the present invention which come within the scope of the following claims are to which the present invention is readily susceptible without departing from the spirit of the invention. The scope of the invention should therefore be determined not with reference to the above description but should be determined with reference to appended claims along with full scope of equivalents to which such claims are entitled.

Reference Numerals:

Material Feeding Hopper (1)
Vibro Feeder (2)
Feeding Belt Conveyor (3)
Rotating Drum Assembly (4)
Drum (41)
Chassis (42)
Material Inlet (43)
Outlet (44)
Dust collecting zone (401)
Lifting Flights (401a)
Rotary screening zone (402)
First rotary screen (402a)
Second rotary screen (402b)
Discharge opening (403)
Pre-separator (5)
Plates (51)
Passage (52)
Rotary air lock valve (53)
Cyclone separator (6)
Exhaust (61)
Rotary air lock valve (62)
Bag house filter (7)
Duct Inlet (71)
Air flow bag cleaning apparatus (72)
Duct Outlet (73)
Common screw conveyor (8)
Exhaust blower (9)
Insulated control panel (10)
Bent exhaust duct (11, 12)