Filtration apparatus

Abstract

A filtration apparatus is provided which is easy to maintain, manage and which enables preservation of filtration characteristics due to the fact that filtration is carried out by use of a gelatinous filter apparatus. In the filtration apparatus, filtration characteristics can be maintained by providing a bubble supplying mechanism for removing a sedimentary layer comprising removables that is formed on a surface of a filtration film and a filtration characteristics restoring mechanism for restoring the filter film clogged by the removables by causing a back-flow of filtered water accumulated in a cistern. Filtration apparatus maintenance and management are facilitated by improving recovery efficiency of the precipitated removables by tapering a lower part inside a raw water tank and providing a recovery tank for recovering removables via a valve.

1 . A filtration apparatus comprising: 
 a tank for housing a fluid containing removables,    a filter apparatus for filtering the fluid,    an air diffuser located under the filter apparatus and generating air bubbles inside the fluid,    an air pump for supplying gas via an air pipe connected to the air diffuser,    wherein the air pipe is provided with an adjustment valve regulated in advance so that a predetermined amount of gas is caused to pass therethrough, and a stop valve for blocking or releasing the gas that passes through the air pipe.    
     
     
         2 . The filtration apparatus of  claim 1 , wherein the air pipe is provided a first path and a second path which are parallel to each other, the first path being provided with a first adjustment valve and a first stop valve and the second path being provided with a second adjustment valve and a second stop valve, wherein an amount of gas flowing through the first adjustment valve is less than an amount of gas flowing through the second adjustment valve.  
     
     
         3 . The filtration apparatus of  claim 2 , wherein when any one of the stop valves is in an open state, the other stop valves are in a close state.  
     
     
         4 . The filtration apparatus of  claim 2 , wherein the air pipe is further provided with a parallel third path, the third path being provided with a third adjustment valve and a third stop valve.  
     
     
         5 . A filtration apparatus comprising: 
 a tank for housing a fluid containing colloidal removables,    a filter apparatus formed of a first filter immersed inside the tank and a second filter comprising a gel film adhered to a surface of the first filter,    an air diffuser located under the filter apparatus and generating air bubbles inside the fluid,    an air pump for supplying gas via an air pipe connected to the air diffuser,    wherein the air pipe is provided with an adjustment valve regulated in advance so that a predetermined amount of gas is caused to pass therethrough, and a stop valve for blocking or releasing the gas that passes inside the air pipe.    
     
     
         6 . The filtration apparatus of  claim 5 , wherein the air pipe is provided a first path and a second path which are parallel to each other, the first path being provided with a first adjustment valve and a first stop valve and the second path being provided with a second adjustment valve and a second stop valve, wherein an amount of gas flowing through the first adjustment valve is less than an amount of gas flowing through the second adjustment valve.  
     
     
         7 . The filtration apparatus of  claim 6 , wherein when any one of the stop valves is in an open state, the other stop valves are in a close state.  
     
     
         8 . The filtration apparatus of  claim 6 , wherein filtration is carried out using the filter apparatus by keeping the first valves only in an open state and mixing the fluid inside the tank by the air bubbles generated from the air diffuser.  
     
     
         9 . The filtration apparatus of  claim 6 , wherein the second filter comprising a gel film is separated from the first filter by keeping the second valves only in an open state and generating air bubbles inside the tank by means of the air diffuser.  
     
     
         10 . The filtration apparatus of  claim 6 , wherein the air pipe is further provided with a parallel third path, the third path being provided with a third adjustment valve and a third stop valve, so that when filtration by the filter apparatus is halted, only the third stop valve is in an open state.  
     
     
         11 . The filtration apparatus of any of the claims from  1  thru  10 , wherein the removables are CMP slurry.  
     
     
         12 . The filtration apparatus of any of the claims from  1  thru  10 , wherein the removables comprise CMP slurry and process waste generated during the CMP process.  
     
     
         13 . A filtration apparatus comprising: 
 a tank for housing a fluid containing removables,    a filter apparatus formed of a first filter immersed inside the tank and a second filter comprising the removables deposited on a surface of the first filter,    a pump connected to the filter apparatus via a pipe,    wherein the second filter is formed by the fluid passing through the first filter by applying a suction pressure from the pump and,    the filter apparatus thus having the second filter formed filters the fluid by causing the fluid to pass by applying a suction pressure from the pump,    wherein the suction pressure of the pump in a process of forming the second filter is larger than in a process of filtering the fluid.    
     
     
         14 . The filtration apparatus of  claim 13 , wherein the pump is provided with an alternating-current motor controlled by an inverter circuit, or a direct-current motor controlled by a voltage.  
     
     
         15 . The filtration apparatus of  claim 13 , wherein the suction pressure is adjusted by a providing a release valve in the pipe.  
     
     
         16 . The filtration apparatus of  claim 13 , wherein a barometer for measuring the suction pressure is provided in the pipe.  
     
     
         17 . The filtration apparatus of  claim 13 , wherein in a process of forming the second filter, the fluid flowing through the pipe is returned to the tank, whereas in a process of filtration, the fluid passing through the pipe is discharged outside of the filtration apparatus.  
     
     
         18 . A filtration apparatus comprising: 
 a tank for housing a fluid containing colloidal removables,    a filter apparatus formed of a first filter immersed inside the tank and a second filter comprising a gel film adhered to a surface of the first filter,    a pump connected to the filter apparatus via a pipe,    wherein the second filter is formed by the fluid passing through the first filter by applying a suction pressure from the pump and,    the filter apparatus thus having the second filter formed filters the fluid by causing the fluid to pass by applying a suction pressure from the pump,    wherein the suction pressure of the pump in a process of forming the second filter is larger than in a process of filtering the fluid.    
     
     
         19 . The filtration apparatus of  claim 18 , wherein the pump is provided with an alternating-current motor controlled by an inverter circuit, or a direct-current motor controlled by a voltage.  
     
     
         20 . The filtration apparatus of  claim 18 , wherein the suction pressure is controlled by providing a release valve in the pipe.  
     
     
         21 . The filtration apparatus of  claim 18 , wherein a barometer for measuring the suction pressure is provided in the pipe.  
     
     
         22 . The filtration apparatus of  claim 18 , wherein in a process of forming the second filter, the fluid flowing through the pipe is returned to the tank, whereas in a process of filtration, the fluid passing through the pipe is discharged outside of the filtration apparatus.  
     
     
         23 . The filtration apparatus pf  claim 18 , wherein the suction pressure is controlled so that a material of the gel forming the second filter does not enter the first filter.  
     
     
         24 . A filtration apparatus comprising: 
 a tank for housing a fluid containing removables,    a filter apparatus immersed inside the tank,    a recovery tank for removables precipitation which communicates with a lower part of the tank via a valve,    wherein the recovery tank is detachable from the tank by closing the valve and detaching the recovery tank from the tank to thus recover removables precipitated in the recovery tank.    
     
     
         25 . The filtration apparatus of  claim 24 , wherein the tank has a tapered bottom and the recovery tank is connected to a lowermost part of the bottom.  
     
     
         26 . The filtration apparatus of  claim 24 , wherein the recovery tank is placed on a transfer vehicle.  
     
     
         27 . The filtration apparatus of  claim 24 , wherein the filter apparatus is formed of a first filter and a second filter comprising removables and deposited on a surface of the first filter and the second filter separated from the first filter precipitates in the recovery tank.  
     
     
         28 . The filtration apparatus of  claim 24 , further comprising an air diffuser for generating air bubbles from a lower part of the filter apparatus, wherein the removables adhered to inner walls of the tank are caused to precipitate to the in the recovery tank by the air bubbles.  
     
     
         29 . A filtration apparatus comprising: 
 a tank for housing a fluid containing colloidal removables,    a filter apparatus formed of a first filter immersed inside the tank and a second filter comprising a gel film adhered to a surface of the first filter,    a recovery tank for removables precipitation which communicates with a lower part of the tank via a valve,    wherein the recovery tank is detachable from the tank by closing the valve and detaching the recovery tank from the tank to thus recover removables precipitated in the recovery tank.    
     
     
         30 . The filtration apparatus of  claim 29 , wherein the tank has a tapered bottom and the recovery tank is connected to a lowermost part of the bottom.  
     
     
         31 . The filtration apparatus of  claim 29 , wherein recovery tank is placed on a transfer vehicle.  
     
     
         32 . The filtration apparatus of  claim 29 , wherein the gelatinous second filter separated from the first filter precipitates in the recovery tank.  
     
     
         33 . The filtration apparatus of  claim 29 , wherein inner walls of the tank comprise a material with excellent water-shedding properties.  
     
     
         34 . The filtration apparatus of  claim 29 , wherein inner walls of the tank comprise a resin.  
     
     
         35 . The filtration apparatus of  claim 29 , further comprising an air diffuser for generating air bubbles from a lower part of the filter apparatus, wherein the removables adhered to inner walls of the tank are caused to precipitate in the recovery tank by the air bubbles.  
     
     
         36 . A filtration apparatus comprising: 
 a tank for housing a fluid containing removables, 
 a filter apparatus formed of a first filter immersed inside the tank and a second filter comprising removables deposited on a surface of the first filter,  
   a pump connected to the filter apparatus via a pipe,    a peel cistern connected to the pipe and storing filtered water filtered by the filter apparatus,    wherein the peel cistern is located at a level above a fluid level of the fluid contained in the tank and when the second filter clogs and a flow rate of the filtered water decreases, the second filter is removed by causing the filtered water accumulated in the peel cistern to flow back in the filter apparatus via the pipe.    
     
     
         37 . The filtration apparatus of  claim 36 , wherein a capacity of the peel cistern is set to be equal or above the sum of the halves of the inner product of each filter apparatus immersed in the fluid.  
     
     
         38 . The filtration apparatus of  claim 36 , wherein upon separation of the second filter, the pump is halted and a suction pressure applied to the filter apparatus is cancelled.  
     
     
         39 . A filtration apparatus comprises: 
 a tank for housing a fluid containing colloidal removables,    a filter apparatus formed of a first filter immersed inside the tank and a second filter comprising a gel film attached to a surface of the first filter,    a pump connected to the filter apparatus via a pipe,    a peel cistern connected to the pipe and storing filtered water filtered by the filter apparatus,    wherein the peel cistern is located at a level above a fluid level of the fluid contained in the tank and when the second filter clogs and a flow rate of the filtered water decreases, the gelatinous second filter is removed by causing the filtered water accumulated in the peel cistern to flow back to the filter apparatus the via the pipe    
     
     
         40 . The filtration apparatus of  claim 39 , wherein a capacity of the peel cistern is set to be equal or above the sum of the halves of the inner product of each filter apparatus immersed in the fluid.  
     
     
         41 . The filtration apparatus of  claim 39 , wherein upon separation of the second filter, the pump is halted and a suction pressure applied to the filter apparatus is cancelled.