Vacuum pumping system provided with a soundproofing arrangement

Abstract

A vacuum pumping system includes a vacuum pump and a soundproofing arrangement. The vacuum pump is accommodated in a pump housing. The soundproofing hood surrounds the pump housing and includes a hood air inlet and a hood air outlet. To improve dampening of the noise generated by the vacuum pumping system, one or more additional soundproofing shielding element(s) is/are provided between the hood air inlet and the pump housing air inlet and/or between the hood air outlet and the pump housing air outlet, respectively. The additional soundproofing shielding element(s) may be designed as a casing surrounding the pump housing and including a casing air inlet and a casing air outlet.

What is claimed is: 
     
         1 . A vacuum pumping system comprising:
 a vacuum pump accommodated in a pump housing; and   a soundproofing hood, which surrounds said pump housing and is provided with a hood air inlet, which is in communication with a pump housing air inlet, and with a hood air outlet, which is in communication with a pump housing air outlet,   wherein one or more additional soundproofing shielding element(s) are provided between said hood air inlet and said pump housing air inlet and/or between said hood air outlet port and said pump housing air outlet.   
     
     
         2 . The vacuum pumping system according to  claim 1 , wherein the additional soundproofing shielding element(s) are designed as a casing which surrounds said pump housing and which is provided with a casing air inlet and with a casing air outlet. 
     
     
         3 . The vacuum pumping system according to  claim 1 , wherein said soundproofing hood comprises a roof and a peripheral wall, which is formed by a plurality of side walls and completely surrounding said pump housing. 
     
     
         4 . The vacuum pumping system according to  claim 3 , wherein said hood air inlet is provided in a first side wall of said peripheral wall of said soundproofing hood, at a certain height above the lower edge of said peripheral wall, and said hood air outlet is provided in a second, opposite side wall of said peripheral wall of said soundproofing hood, close to the lower edge of said peripheral wall. 
     
     
         5 . The vacuum pumping system according to  claim 2 , wherein said casing has a top wall, a peripheral wall, formed by a plurality of side walls and completely surrounding said pump housing and a drive motor, and a bottom wall. 
     
     
         6 . The vacuum pumping system according to  claim 5 , wherein said casing air inlet is provided in one of the side walls forming said peripheral wall of said casing and said casing air outlet is provided in said bottom wall of said casing. 
     
     
         7 . The vacuum pumping system according to  claim 6 , wherein:
 said hood air inlet is provided in a first side wall of said peripheral wall of said soundproofing hood, at a certain height above the lower edge of said peripheral wall, and said hood air outlet is provided in a second, opposite side wall of said peripheral wall of said soundproofing hood, close to the lower edge of said peripheral wall; and   said soundproofing hood is arranged with respect to said casing so that said first side wall of said peripheral wall of said soundproofing hood in which said hood air inlet is provided is on the opposite side with respect to said side wall of said peripheral wall of said casing in which said casing air inlet is provided.   
     
     
         8 . The vacuum pumping system according to  claim 6 , wherein said vacuum pumping system further comprises a soundproofing tray arranged below said bottom wall of said casing, at said casing air outlet. 
     
     
         9 . The vacuum pumping system according to  claim 2 , wherein said soundproofing hood is provided with a partition extending from an inner wall of said soundproofing hood to an outer wall of said underlying casing and separating a space in which said hood air inlet and said casing air inlet are arranged from a space in which said hood air outlet and said casing air outlet are arranged. 
     
     
         10 . The vacuum pumping system according to  claim 9 , wherein said partition is formed as a peripheral frame extending all along the inner side of said peripheral wall of said soundproofing hood, at a height below said hood air inlet and above said hood air outlet, and extending to the outer wall of said casing. 
     
     
         11 . The vacuum pumping system according to  claim 1 , wherein said soundproofing hood and/or said one or more additional soundproofing shielding element(s) have a multi-layered structure comprising two or more layers made of soundproofing material. 
     
     
         12 . The vacuum pumping system according to  claim 11 , wherein said soundproofing hood and/or said one or more additional soundproofing shielding element(s) have a first, inner layer made of a sound-absorbing material and a second, outer layer made of sound-insulating material. 
     
     
         13 . The vacuum pumping system according to  claim 1 , wherein said vacuum pumping system further comprises a drive motor for driving said vacuum pump and/or a cooling fan for cooling said vacuum pump. 
     
     
         14 . The vacuum pumping system according to  claim 1 , wherein said vacuum pump is a rotary vane vacuum pump including a pump stator defining a cylindrical stator chamber and a pump rotor received in said stator chamber and having an axis parallel to the axis of the stator chamber and eccentrically arranged relative to the stator chamber axis, said pump stator and said pump rotor being accommodated in said pump housing and said pump housing being filled with oil. 
     
     
         15 . A vacuum pumping system comprising:
 a vacuum pump accommodated in a pump housing,   a casing, which surrounds said pump housing and which is provided with a casing air inlet and with a casing air outlet; and   a soundproofing hood, which covers said casing and is provided with a hood air inlet, which is in communication with said casing air inlet, and with a hood air outlet, which is in communication with said casing air outlet,   wherein said soundproofing hood is provided with a partition extending from an inner wall of said soundproofing hood to an outer wall of said underlying casing and separating a space in which said hood air inlet and said casing air inlet are arranged from a space in which said hood air outlet and said casing air outlet are arranged.