Blast Protection Damper

Abstract

A blast wave damper comprises a section of duct ( 14 ), with a multiplicity of rigid elements ( 18 ) each extending across the duct. All the elements are parallel to each other, and they are arranged in an array consisting of a multiplicity of lines, each such line extending across the duct ( 14 ). The elements in one line are staggered relative to the elements in an adjacent line, and the gaps between successive elements within a line are no wider than the widths of the elements. There may be ten columns of tubular elements in a regular array. This may be combined with a louvre mechanism ( 20 ) arranged to shut if the pressure drop exceeds a threshold.

1 . A blast protection damper comprising a section of duct, with a multiplicity of substantially rigid elements each extending across the duct the elements all extending parallel to each other and being arranged in an array consisting of a multiplicity of lines of said elements, each such line extending across the duct, the elements in one line being staggered relative to the elements in an adjacent line, and the gaps between successive elements within a line being no wider than the widths of the elements. 
   
   
       2 . A damper as claimed in  claim 1  wherein the lines are straight lines, and within each line the elements are equally spaced. 
   
   
       3 . A damper as claimed in  claim 1  wherein there are between eight and fifteen lines of elements in the array. 
   
   
       4 . A damper as claimed in  claim 3  wherein there are ten lines of elements in the array. 
   
   
       5 . A damper as claimed in any one of the preceding  claim 1  wherein the elements are of cylindrical shape. 
   
   
       6 . A damper as claimed in  claim 1  wherein the elements within a single line occupy at least 50% of the projected area. 
   
   
       7 . A damper as claimed in  claim 1  also comprising a louvre which is arranged to shut if the pressure in the duct exceeds a threshold. 
   
   
       8 . A damper as claimed in  claim 5  wherein the elements are tubular.