Grating and clean room system comprising the same

Abstract

Grating forming the floor of a clean room minimizes turbulence and enhances the rate at which air is discharged therethrough. The grate includes a base plate having a plurality of through-holes. Each of the through-holes includes a receiving portion through which the air is received and an exhausting portion through which the air is exhausted. The cross-sectional area of the receiving decreases toward the exhausting portion, and the cross-sectional area of the exhausting portion decreases toward the receiving portion.

1 . A grating for as flooring in a clean room, the grate comprising a base plate having a plurality of holes therethrough that serve as channels through which the air in the clean room is discharged, 
 wherein each of the holes has a receiving portion open at one side of the base plate and an exhausting portion open at the other side of the base plate,    the cross-sectional area of the receiving portion decreasing in a direction from said one side of the base plate toward the exhausting portion, and    the cross-sectional area of the exhausting portion decreasing in a direction from said other side of the base plate toward the receiving portion.    
   
   
       2 . The grate as set forth in  claim 1 , wherein the grate has frusto-conical surfaces that define the receiving portion and the exhausting portion, respectively, of each of the holes.  
   
   
       3 . The grate as set forth in  claim 1 , wherein the grate has curved surfaces that define the receiving portion and the exhausting portion respectively, of each of the holes.  
   
   
       4 . The grate as set forth in  claim 1 , wherein each of the holes has a circular cross-sectional shape.  
   
   
       5 . The grate as set forth in  claim 1 , wherein each of the holes has an elongate cross-sectional shape so as to be in the form of a slot.  
   
   
       6 . The grate as set forth in  claim 1 , wherein each of the holes has a middle portion extending a finite distance between the receiving portion and the exhausting portion, the middle portion of the hole having a uniform cross section from the receiving portion to the exhausting portion.  
   
   
       7 . The grate as set forth in  claim 1 , further comprising a tile of polyvinyl chloride attached to the top surface of the base plate.  
   
   
       8 . The grate as set forth in  claim 1 , wherein the total area of ends of the holes at said one side of the grate is about 18% of the total area of said one side of the grate.  
   
   
       9 . The grate as set forth in  claim 1 , wherein the diameter of the widest portion of each of the holes is about 10 mm, and the diameter of the narrowest portion of each of the holes is about 8.5 mm.  
   
   
       10 . A clean room system comprising: 
 a clean room having a ceiling and a floor;    at least one of a fan and a filter disposed in the ceiling of the clean room; and    grating disposed in the floor of the clean room, the grating defining a plurality of holes through which air inside the clean room is discharged through the floor of the clean room, the grating having one side exposed to the interior of the clean room, and another side facing away from the interior of the clean room, and    the cross-sectional area of each of the holes decreasing and then increasing in a direction from said one side of the grating to said another side of the grating.    
   
   
       11 . The clean room system as set forth in  claim 10 , 
 wherein each of the holes of the grating has a receiving portion open at said one side of the grating and an exhausting portion open at the other side of the grating,    the cross-sectional area of the receiving portion decreasing in a direction from said one side of the grating toward the exhausting portion, and    the cross-sectional area of the exhausting portion decreasing in a direction from said another side of the grating toward the receiving portion.    
   
   
       12 . The clean room system as set forth in  claim 11 , wherein the grating has frusto-conical surfaces that define the receiving portion and the exhausting portion, respectively, of each of the holes.  
   
   
       13 . The clean room system as set forth in  claim 11 , wherein the grating has curved surfaces that define the receiving portion and the exhausting portion respectively, of each of the holes.  
   
   
       14 . The clean room system as set forth in  claim 11 , wherein each of the holes of the grating has a middle portion extending a finite distance between the receiving portion and the exhausting portion, the middle portion of the hole having a uniform cross section from the receiving portion to the exhausting portion.  
   
   
       15 . The clean room system as set forth in  claim 10 , wherein each of the holes of the grating has a circular cross-sectional shape.  
   
   
       16 . The clean room system as set forth in  claim 10 , wherein each of the holes of the grating has an elongate cross-sectional shape so as to be in the form of a slot.  
   
   
       17 . The clean room system as set forth in  claim 10 , wherein the grating comprises a tile made of polyvinyl chloride at the top thereof.