Light weight vaneless compressor containment design

Abstract

A vaneless compressor containment design has an inner bolt circle with more than three fasteners situated in the vaneless space to cut up tri-hub pieces to smaller pieces prior to reaching an outer bolt circle and its associated flange. This containment design may allow a thinner radial wall thickness for the outermost flange as compared to the conventional design. The thinner radial wall thickness may reduce the weight of the compressor. This weight reduction may be achieved with little or no increase in the compressor space envelope.

1 . A system for an impeller comprising:
 a housing surrounding the impeller;   a diffuser passage defined by the housing; and   first and second sets of fasteners or passage obstructers having shoulders or obstructing portions, the obstructing portions extending through the diffuser passage, wherein   the first set of passage obstructers is disposed circumferentially about a first radius;   the second set of passage obstructers is disposed circumferentially about a second radius; and   the first radius is smaller than the second radius.   
     
     
         2 . The system of  claim 1 , wherein the length of the obstructing portions are greater than the width of the diffuser passage. 
     
     
         3 . The system of  claim 1 , wherein the fasteners or passage obstructers include a fastener portion having a fastener shoulder, and wherein the diameter of the obstructing portion is less than or equal to the diameter of the fastener shoulder. 
     
     
         4 . The system of  claim 1 , wherein said diffuser passage comprises a vaneless diffuser. 
     
     
         5 . The system of  claim 1 , wherein the passage obstructer includes a fastener portion, wherein the housing comprises a shroud, scroll proper, scroll flange, and scroll backing housing, wherein the scroll backing housing and shroud are tied by the first set of fasteners, and the scroll backing housing and the scroll flange are tied by the second set of fasteners. 
     
     
         6 . The system of  claim 1 , wherein the fasteners or passage obstructers are in contact with the housing and extend axially though the diffuser passage. 
     
     
         7 . The system of  claim 1 , wherein each of the first set of fasteners or passage obstructers is arranged equidistantly between adjacent ones of the second set of fasteners or passage obstructers. 
     
     
         8 . The system of  claim 1 , wherein the first set of fasteners or passage obstructers includes seven passage obstructers arranged equidistantly about a circumference defined by the first radius. 
     
     
         9 . The system of  claim 8 , wherein the second set of fasteners or passage obstructers includes seven passage obstructers arranged equidistantly about a circumference defined by the second radius. 
     
     
         10 . The system of  claim 9 , wherein each of the first set of passage obstructers is arranged equidistantly between adjacent ones of the second set of passage obstructers. 
     
     
         11 . The system of  claim 1 , wherein:
 the first set of passage obstructers are disposed between a scroll and the impeller; and   the second set of passage obstructers are disposed between the scroll and a housing containment structure.   
     
     
         12 . The system of  claim 1 , wherein the first and second passage obstructers are disposed between a housing containment structure and the impeller. 
     
     
         13 . A containment system for a compressor having a vaneless diffuser comprising first and second sets of passage obstructers having obstructing portions, the obstructing portions extending through a diffuser passage, wherein
 the first set of passage obstructers is disposed circumferentially about a first radius;   the second set of passage obstructers is disposed circumferentially about a second radius; and   the first radius is smaller than the second radius.   
     
     
         14 . The system of  claim 13 , wherein the first set of passage obstructers includes seven passage obstructers arranged equidistantly about a circumference defined by the first radius. 
     
     
         15 . The system of  claim 14 , wherein the second set of passage obstructers includes seven passage obstructers arranged equidistantly about a circumference defined by the second radius. 
     
     
         16 . The system of  claim 15 , wherein each of the first set of passage obstructers is arranged equidistantly between adjacent ones of the second set of passage obstructers. 
     
     
         17 . A method of containing a burst impeller fragment in case an impeller bursts during operation of a compressor, comprising:
 obstructing a predicted path of the burst impeller fragment with first and second sets of passage obstructers having obstructing portions, the first set of passage obstructers being disposed circumferentially about a first radius, the second set of passage obstructers being disposed circumferentially about a second radius, and the first radius being smaller than the second radius, such that if the impeller bursts during the operation of the compressor, at least a portion of the energy of the burst impeller fragment will be absorbed by at least one of the obstructing portions.   
     
     
         18 . The method of  claim 17 , wherein obstructing the predicted path of the burst impeller fragment includes obstructing the predicted path of the burst impeller fragment such that the radial movement of the burst impeller fragment is capable of being halted by contact with the passage obstructer. 
     
     
         19 . The method of  claim 17 , wherein the predicted path is obstructed such that the velocity of the burst impeller fragment will be reduced by contact with the passage obstructer if the impeller bursts during the operation of the compressor. 
     
     
         20 . The method of  claim 17 , wherein the obstructing of the predicted path is performed such that at least a portion of the energy absorbed will be absorbed by bending of at least one of the obstructing portions upon being impacted by the burst impeller fragment.