Drying chamber, drying unit, drier of recycled abrasive and method for drying wet recycled abrasive

Abstract

Drying of recycled abrasive that can be recycled separated or as a part of the full recycling system. Sorted and meshed wet recycled abrasive is kept in a hopper for wet recycled abrasive, it is continuously delivered using a screw feeder into a drying chamber on a vibration mesh. Air is blown in the chamber, using an air flow generator, under a vibration mesh. The recycled abrasive is moved and lifted on the mesh using air flow and mesh vibration, this provides for clots of recycled abrasive to break down to particles of recycled abrasive and abrasive mixes and dries.

Claims

1. A drying chamber (5) for drying of recycled abrasive characterized by the fact that it contains a vibrating mesh (12), a collecting vessel (13) with sloped bottom, that is positioned above the vibrating mesh (12) and occupies 50 to 80% of area above the vibrating mesh (12), which limits a free space (16) where a vertical blades (20) are positioned, between an internal wall of the drying chamber (5) and an external wall of the collecting vessel (13) and the collecting vessel (13) empties into an output (15) of dry recycled abrasive from the drying chamber (5).

2. The drying chamber (5) for drying of recycled abrasive according to claim 1 characterized by the fact that the bottom of the collecting vessel (13) is sloped towards the vibrating mesh (12) with angle 5 to 20.

3. The drying chamber (5) for drying of recycled abrasive according to claim 1 or 2 characterized by the bottom of the collecting vessel (13) contains a groove (25) that empties into the output (15) of dry recycled abrasive from the drying chamber (5).

4. The drying chamber (5) for drying of recycled abrasive according to claim 1 characterized by the fact that it has sensors (23) installed to detect quantity of recycled abrasive.

5. The drying chamber (5) for drying of recycled abrasive according to claim 1 characterized by the fact that a vibration frame (14) has been fixed to vibrating mesh (12) and two vibro motors (11) are fixed to it.

6. The drying chamber (5) for drying of recycled abrasive according to claim 1 characterized by the fact that the vibro motors (11) work at 2000 to 4000 rpm.

7. A drying unit (22) characterized by the fact that it consists of drying chamber (5) according to claim 1, connected in its upper part to a chimney (18) for exhaust of dust particles and connected in its lower part to an air chamber (17), wherein the chimney (18) in fitted with input (19) of wet recycled abrasive and an air outlet (F) and the air chamber (17) empties to a source (6) of air flow.

8. The drying unit (22) according to claim 7 characterized by the fact that the source (6) of air flow generates air with velocity 0.76 to 1.23 m/s and pressure 498 to 306 Pa.

9. The drying unit (22) according to claim 8 characterized by the fact that the source (6) of air flow generates air with velocity 0.85 to 1.04 m/s and pressure 442 to 362 Pa.

10. The drying unit (22) according to claim 7 characterized by the fact that the source (6) of air flow is a fan.

11. The drying unit (22) according to claim 10 characterized by the fact that the fan sucks waste heat from a hydraulic oil cooler.

12. A drier of recycled abrasive (21) with a cyclone separator (9) characterized by the fact that it contains the drying unit (22) according to claim 7, a hopper (3) for wet recycled abrasive, a hopper (7) for dry recycled abrasive and a scale (8), where a screw feeder (4) is positioned in narrow bottom of the hopper (3) for wet recycled abrasive, which empties into an input (19) of wet recycled abrasive into the drying unit (22), the chimney (18) of the drying unit (22) empties into the upper part of the cyclone separator (9) and an output (15) of dry recycled abrasive from the drying chamber (5) empties to its lower part, the lower part of the cyclone separator (9) is tightly connected to the hopper (7) for dry recycled abrasive and the hopper (7) for dry recycled abrasive is placed on the scale (8).

13. The drier of recycled abrasive (21) according to claim 11 characterized by output (15) of dry recycled abrasive from the drying chamber (5) is equipped with the sensor (23).

14. A method for drying wet recycled abrasive using the drying chamber (5) according to claim 1 characterized by the fact that the drying chamber (5) is inserted into air flow with velocity 0.78 to 1.23 m/s and pressure 500 to 300 Pa, which is heated with waste heat from operation of machines for hydroabrasive separation with water jet, the vibrating mesh (12) vibration is set off, with rate 1500 rpm or more, wet recycled abrasive (C) is delivered to the vibrating mesh (12) and dry recycled abrasive (D) from the output (15) of dry recycled abrasive from the drying chamber is collected into the hopper (7) for dry recycled abrasive.

Description

SUMMARY OF PRESENTED DRAWINGS

(1) FIG. 1: Schematic drawing of recycled abrasive drier

(2) FIG. 2: Detail cut view of drying chamber

(3) FIG. 3: Side view of recycled abrasive drier

(4) FIG. 4: View of recycled abrasive drier

(5) FIG. 5: Top view of recycled abrasive drier

(6) FIG. 6: View of collecting vessel with mesh

(7) FIG. 7: Detail of collecting vessel

(8) FIG. 8: Table of drying process with various level of moisture of recycled abrasive and various temperature of flowing air

(9) FIG. 9: Chart of dependence of drying time on moisture of recycled abrasive and temperature of flowing air

(10) FIG. 10: Chart of dependence of temperature of flowing air on drying output with entry moisture level of recycled abrasive 10%, 7% and 4%

EXAMPLES OF INVENTION EXECUTION

Example 1

(11) Drying Chamber 5

(12) Drying chamber 5 involved vibrating mesh 12 fixed to vibration frame 14 along the perimeter and also in the centre, namely using a system 24 to fix the mesh, drying chamber 5 involved also collecting vessel 13 positioned above the mesh 12 which had the bottom sloped towards outlet 15 of dry recycled abrasive from the drying chamber. 5 vertical blades 20 were positioned in space 16 between the wall of drying chamber 5 and the wall of collecting vessel 13 to deflect grains of recycled abrasive into vertical movement.

Example 2

(13) Process of Recycled Abrasive DryingAlmandine Garnet of Australian Origin in Equipment from Example 1

(14) Almandine garnet of Australian origin contained SiO.sub.2, Al.sub.2O.sub.3, FeO, grain size 150-300 m, 80 MESH. Drying chamber 5 was positioned in air flow E with velocity 0.87 m/s, pressure 432 Pa and temperature 35 C. Mesh vibration 12 was ON, 10 kg of wet recycled abrasive with moisture of 15% was dosed on mesh 12. Drying time of recycled abrasive was 11 minutes, when all the dried recycled abrasive was transported to outlet 15 of dry recycled abrasive from the drying chamber 5.

Example 3

(15) Process of Abrasive DryingAlmandine Garnet of Australian Origin in Equipment from Example 1

(16) Almandine garnet of Australian origin contained SiO.sub.2, Al.sub.2O.sub.3 and FeO, grain size 200-600 m, 50 MESH. Drying chamber 5 was positioned in air flow E with velocity 0.87 m/s, pressure 432 Pa and temperature 35 C. Mesh vibration 12 was ON, 10 kg of wet recycled abrasive with moisture of 15% was dosed on mesh 12. Drying time of recycled abrasive was 12.5 minutes, when all the dried recycled abrasive was transported to outlet was transported to outlet 15 of dry recycled abrasive from the drying chamber 5.

Example 4

(17) Drier of Recycled Abrasive 21 in Static Conditions

(18) Drier of recycled abrasive 21 involved hopper 3 wet recycled abrasive which was connected using screw feeder 4 to drying unit 22, cyclone separator 9 and hopper 7 of dry recycled abrasive with a scale.

(19) Drying unit 22 involved drying chamber 5, chimney 18 and air chamber 17. Chimney 18 emptied with air outlet F into cyclone separator 9, it was fitted with inlet 19 of wet recycled abrasive from screw feeder 4, which was placed on bottom of feeder 3 of wet recycled abrasive. Two vibro motors 11 fixed to vibration frame 14 were positioned in the upper part of air chamber 17 and air chamber 17 emptied to the fan which was used as source 6 of air flow. Drying chamber 5 involved vibrating mesh 12 fixed to vibration frame 14 along the perimeter and also in the centre, namely using system 24 to fix the mesh, drying chamber 5 also contained collecting vessel 13 with height 100 mm and diameter 400 mm. Collecting vessel 13 was positioned above mesh 12 with diameter 680 mm, and 30 mm above this mesh 12. 6 vertical blades 20 were positioned in space 16 between the wall of drying chamber 5 and the wall of collecting vessel 13 to deflect grains of recycled abrasive into vertical movement. Air from air chamber 17 flowed through mesh 12 upwards into drying chamber 5. Vibrating mesh 12 shook grains of recycled abrasive and they moved along the perimeter of drying chamber 5. The total height that the grains of recycled abrasive had to overcome to get into collecting vessel 13 was 130 mm. Collecting vessel 13 had a groove terminating in outlet 15 in its bottom sloped towards outlet 15 of dry recycled abrasive from drying chamber 5, and the other end of the outlet terminated in a wall of cyclone separator 9 to its low edge which provided for sealing of the system and the hopper of dry recycled abrasive was connected to cyclone separator 9 tightly which prevented loss of recycled abrasive and its whirling around. Sensor 23 was positioned at the end of pipe of outlet 15

(20) Chimney 18 emptied in the cyclone separator to remove small dust off outlet air F. After entry of dry recycled abrasive into cyclone separator 9, centrifugal force separated particles of recycled abrasive from air flow. Dry recycled abrasive D fell because of gravy down into connected hopper 7 for dry recycled abrasive (large capacity sack) which was laid on pallet scale 8 which provided for continuous monitoring of weight of dry recycled abrasive D.

Example 5

(21) Drying Process in Drier of Recycled Abrasive 21

(22) Hopper for wet recycled abrasive 3 was filled with wet recycled abrasive, almandine garnet of Australian origin with weight 300 kg, grain size 150-300 m, 80 MESH. We started the fan, then we started vibration of vibration mesh 12 at frequency 3000 rpm, screw feeder 4 loaded the first dose of recycled wet abrasive with weight 1.5 kg and moisture 10% from hopper 3. Recycled abrasive moved on vibration mesh 12, it was aerated with incoming air with flow rate 5400 m.sup.3/hour, velocity 1.5 m/s and pressure 398 Pa with temperature 25 C. Weight increase was monitored using a scale, the process dosingdryingweighting was repeated after weight increase on the scale minus 10% (water share) in loaded weight of wet recycled abrasive C was achieved.

(23) After screw feeder 4 was empty, the equipment was switched OFF automatically. 270 kg of recycled abrasive has got dry, the drying time was 7.2 hours, recycled abrasive lost 26.7 kg of its weight compared with wet conditions, which is just 10%.

Example 6

(24) Drying Unit 22 in Static Conditions

(25) Drying unit 22 involved drying chamber 5, chimney 18 and air chamber 17. Chimney 18 was fitted with inlet 19 for wet recycled abrasive and ait outlet F. Two vibro motors 11 fixed to vibration frame 14 were positioned in the upper part of air chamber 17 and air chamber 17 emptied into a fan, which was used as source 6 of air flow.

(26) Drying chamber 5 involved vibrating mesh 12 fixed to vibration frame 14 and collecting vessel 13 with height 156.5 mm and diameter 500 mm. Collecting vessel 13 was sloped at 12 towards mesh 12, it had groove 25, which emptied into outlet 15 of dry recycled abrasive from the drying chamber 5, collecting vessel 13 was positioned concentrically with mesh 12 with diameter 710 mm and height 28.5 mm above mesh 12. Air flow occurs in annulus space 16 (710/500 mm) and it lifts and aerates recycled abrasive to dry. There were 8 vertical blades 20 to deflect grains into vertical movement. The total height that the grains of abrasive had to overcome was 185 mm. Sensors 23 were installed on collecting vessel 13 to detect quantity of dry recycled abrasive, providing for continuous drying process with optimum rate of dosing of wet recycled abrasive.

Example 7

(27) Process of Drying Recycled Abrasive in Drying Unit 22

(28) Drying of almandine garnet of Australian origin containing SiO.sub.2, Al.sub.2O.sub.3 and FeO.

(29) The operator relieved the scale before starting the process, switched the main switch ON, calibrated (reset) the scale, again loaded the scale with dry recycled abrasive, switched the equipment, the control system detected 100 kg of dry recycled abrasive on output. Hopper for wet recycled abrasive 3 was filled with wet recycled abrasive with weight 400 kg, grain size 150-300 m, 80 MESH. We started the fan, then we started vibration of vibration mesh 12 at frequency 3000 rpm, screw feeder 4 loaded the first dose of recycled wet abrasive with weight 2 kg and moisture 10% from hopper 3.

(30) Recycled abrasive moved on the vibration mesh, it was aerated with incoming air with velocity 1 m/s and pressure 375.47 Pa and temperature 22 C. Weight increase was monitored using a scale, the process dosingdryingweighting was repeated after weight increase on the scale minus 10% (water share) in loaded weight of wet recycled abrasive was achieved.

(31) After hopper 3 and screw feeder 4 were empty, the equipment was switched OFF automatically. 358 kg of recycled abrasive has got dry, the drying time was 12 hours, recycled abrasive lost 42 kg of its weight compared with wet conditions.

Example 8

(32) Process of Drying Recycled Abrasive in Drying Unit 22

(33) The operator relieved the scale before starting the process, switched the main switch ON, calibrated (reset) scale 8, again loaded scale 8 with dry recycled abrasive, switched the equipment, the control system detected 50 kg of dry recycled abrasive on output. Hopper for wet recycled abrasive 3 was filled with wet recycled abrasive, namely mixture of SiO.sub.2 and Al.sub.2O.sub.3 with weight 420 kg and average moisture 9.8%, grain size was 300-150 m, 80 MESH. We started the fan which is source (6) of air flow (E) with acoustic pressure 77 dB with air flow 1.5 m.sup.3/s. Then vibro motors 11 were switched ON to vibrate vibration mesh 12 at frequency 3000 rpm. Screw feeder 4 delivered the first dose of recycled wet abrasive with weight 1.5 kg and moisture 15.5% from hopper 3 for wet recycled abrasive to mesh 12. Moisture of loaded wet recycled abrasive decreased during the process, as the highest share of water left bottom of hopper 3 for wet recycled abrasive in the first doses of wet recycled abrasive.

(34) Recycled abrasive moved on vibration mesh 12, it was aerated with incoming air with air speed 1.02 m/s, temperature 24 C. and pressure 368.52 Pa. Weight increase was monitored using scale 8, the process dosingdryingweighting was repeated after weight increase on the scale minus 10% (water share) in loaded weight of wet recycled abrasive was achieved. 420 kg of recycled abrasive has got dry, the drying time was 6 hours, recycled abrasive lost 42.5 kg of its weight, compared with wet conditions, which corresponds to moisture of recycled abrasive and removed dust particles. The output of the drying process was 33 kg/hour.

Example 9

(35) Process of Abrasive Drying in Drying Unit 22

(36) Hopper 3 for wet recycled abrasive was filled with wet recycled abrasive mixture of SiO.sub.2, Al.sub.2O.sub.3 and FeO with weight 283 kg and average moisture 10%, grain size was 300-150 m, 80 MESH. We started the fan with air flow 1.5 m.sup.3/sec. Then vibro motors 11 were switched ON to vibrate vibration mesh 12 at frequency 3000 rpm. Screw feeder 4 delivered the first dose of recycled wet abrasive with weight 1.5 kg and moisture 15.5% from hopper 3 for wet recycled abrasive to mesh 12

(37) Moisture of loaded abrasive decreased during the process, as the highest share of water left bottom of hopper 3 for wet recycled abrasive in the first doses of wet abrasive.

(38) Recycled abrasive moved on vibration mesh 12, it was aerated with incoming air with air speed 1.02 m/s, temperature 19 C. and pressure 368.52 Pa. Weight increase was monitored using scale 8, the process dosingdryingweighting was repeated after weight increase on the scale minus 10% (water share) in loaded weight of wet recycled abrasive was achieved. 257 kg of recycled abrasive has got dry, the drying time was 15.5 hours, recycled abrasive lost 25.7 kg of its weight compared with wet conditions, which corresponds to moisture of recycled abrasive and removed dust particles. The output of the drying process was 19 kg/hour.

Example 10

(39) We performed a test with variable rate of air flow, namely 1.04 m/s to 1.23 m/s, and transport pressure in range 306-360 Pa in change in sine curve with wave with time change 20 seconds at air temperature 23 C.

(40) The total drying time was 1.1 hour and quantity of dry recycled abrasive was 72.3 kg. The input wet recycled abrasive had moisture 10%. The drying process was quite efficient, 66 kg of recycled abrasive per hour has got dry.

Example 11

(41) Dependence of flowing air temperature on drying time of recycled abrasive was examined. The tests ran with input specimen 10 kg. The results concerning achieved times, energy input and temperature are presented in FIGS. 8 to 10. Above all, link between air flow temperature and energy input must be considered as change of temperature because of additional heating. Then, temperature always changes according to change in power input. This fact must be considered as increase of drying potential not only because of higher temperature but also because of lower relative air humidity. From the results we can derive linear dependence both in energy inputdrying capacity and input moisturedrying capacity. This finding allows to deduce that the drying rate of input is proportional to its moisture which had not been considered. The original assumption was that when water quantity in recycled abrasive decreases, more recycled abrasive can lift and drying will be more efficient.

LIST OF MARKS FOR TERMS

(42) A. Input of mixture from cutting bench B. wastefine fraction C. wet recycled abrasive D. dry recycled abrasive E. air input F. air output 1. desludging 2. desludging separator 3. hopper for wet recycled abrasive 4. feeder 5. drying chamber 6. source of air flow 7. hopper for dry recycled abrasive 8. scale 9. cyclone separator 10. electric panel 11. vibro motor 12. mesh 13. collecting vessel 14. vibration frame 15. output of dry recycled abrasive from the drying chamber 5 16. free space between wall of collecting vessel 13 and wall of drying chamber 5 17. air chamber 18. chimney 19. input of wet recycled abrasive into drying unit 21 20. blades 21. drier of recycled abrasive 22. drying unit 23. sensor 24. system to fix mesh 25. groove of collecting vessel 13 26. wall of collecting vessel 13

APPLICABILITY IN INDUSTRY

(43) Cutting with high pressure water jet, accessories to CNC machines for cutting with high pressure water jet. Recycling abrasive material used for cutting with high pressure water jet.