BRIEF DESCRIPTION OF DRAWINGS
The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
FIG. 1 is a conventional slurry supply system;
FIGS. 2, 3 and 4 are a schematic views of a slurry supply system of the invention;
FIG. 5 depicts loop A of the slurry supply system of the invention undergoing cleaning by a tank with KOH solution;
FIG. 6 depicts a combination of two slurry supply systems of the invention; and
FIG. 7 depicts combination of a conventional slurry supply system and a slurry system of the invention.
DETAILED DESCRIPTION OF INVENTION
FIG. 2 depicts a slurry supply system of the invention. The slurry supply system comprises a supply unit 100, a loop A and a loop B. The supply unit 100 comprises a station A and a station B. In this embodiment, the station A and station B have the same structure. The station A comprises a tank 10, a pump 20, and a first valve module having valves 30, 40, 50, 601, 603 and 604 (first valve, second valve, third valve, sixth valve, fifth valve and fourth valve). The station B comprises a tank 10′, a pump 20′, and a second valve module having valves 30′, 40′, 50′, 602, 605 and 606 (seventh valve, eighth valve, ninth valve, twelfth valve, eleventh valve and tenth valve). The loop A is connected to both the station A and station B, and the loop B is also connected to both station A and station B. The loop A is connected to the station A via the valves 30, 40, 50, and to the station B via the valves 30′, 40′ and 50′. The loop B is connected to the station A via the valves 603 and 604, and to the station B via the valves 605 and 606. When the valves 30 and 40 are opened, and the valve 50 is closed, slurry is driven by the pump 20 from the tank 10 to the loop A. When the valves 30 and 40 are closed, and the valve 50 is opened, slurry in runs through station A. When valve 603 and 604 are opened and the valve 601 is closed, slurry is driven by the pump 20 from the tank 10 to the loop B. When valve 603 and 604 are closed and the valve 601 is opened, slurry runs through station A. When the valves 30′ and 40′ are opened and the valve 50′ is closed, slurry is driven by the pump 20′ from the tank 10′ to loop A. When the valves 30′ and 40′ are closed and the valve 50′ is opened, slurry runs through station B. When the valves 605 and 606 are opened and the valves 602 are closed, slurry is driven by the pump 20′ from the tank 10′ to loop B. When the valves 605 and 606 are closed and the valves 602 are opened, slurry runs through station B. Slurry selectively runs in loop A or loop B. Loop A is connected to the points of use via a first valve device 120, and the loop B is connected to the points of use via a second valve device 140.
In FIG. 2, slurry is supplied from the station A to the points of use 500 via the loop A with the valves 30, 40 and 50′ open. The loop A is indicated by a thick line for slurry supply and the loop B is indicated by a thin line for no slurry supply. When the loop A is to be maintained, the station B supplies slurry to the loop B with the valves 601, 605 and 606 open and the valves 602, 603 and 604 closed. At this time, slurry in the loop A still runs, as shown in FIG. 3, the loop A and the loop B are both indicated by thick lines. When slurry in the loop B reaches a stable state, the first valve device 120 is gradually closed and the second valve device 140 is gradually opened simultaneously. When the first valve device 120 is completely closed and the second valve device 140 is completely open, slurry is supplied from the station B to the points of use 500 via the loop B, as shown in FIG. 4. The loop B is indicated by a thick line and the loop A is indicated by a thin line. The station A shuts down. A tank 800 filled with KOH solution is connected to loop A as shown in FIG. 5. Pump 810 circulates KOH solution in loop A for cleaning. The tank 800 can also be connected to loop B for cleaning. The KOH solution in tank 800 can also be used to clean station A, station B or points of use 500 via loop A or loop B.
In conventional use, when slurry is expended, slurry supply can be switched from station A to station B. In the invention, as loop A and loop B are independently connected to station A and station B, slurry can be supplied from station A to station B or from station B to station A when either loop A or loop B is used. For example, when loop A is used and slurry is supplied from station A and slurry is expended, slurry supply can be switched from station A to station B. Station A is replenished. After a certain period when loop A is to be maintained and the station A is replenished, slurry can be supplied from station A to loop B with the valves 602, 603 and 604 open and the valves 601, 605 and 606 closed. When slurry in loop B reaches a stable state, the second valve device 140 is gradually opened and the first valve device 120 is gradually closed, whereby the slurry supply is switched from loop A to loop B.
FIG. 6 depicts combination of two slurry supply systems of the invention. Station B in slurry supply system 1000 is connected to Station B in slurry supply system 2000. Slurry can be provided from slurry supply system 1000 to slurry supply system 2000 to replenish station B in supply system 2000.
FIG. 7 depicts combination of a conventional slurry supply system and a slurry system of the invention. Station B in the slurry supply system 1000 of the invention is connected to the station A of the conventional slurry system 3000. Slurry can be provided from the conventional slurry supply system 3000 to slurry system 1000.
While the invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.