MUFFLER Russian patent published in 2007 - IPC F01N1/24 

FIELD: mechanical engineering.

SUBSTANCE: invention relates to device s for silencing aerodynamic noise of pneumatic equipment and compressed gas or air exhaust systems. Proposed muffler contains intake branch pipe and housing made of porous material and rigidly coupled with intake branch pipe. Housing contains lower and upper covers with grooves for fixing outer cylindrical bushing made of porous material. Covers of housing are interconnected by inner cylindrical bushing by means of screw engaging with threaded part of bushing. Calibrated holes, diameter d, are made in bushing. Axes of calibrated holes are square to axis of bushing, and cylindrical cup-screen is attached from outside to upper cover of housing. Ratio of height B of housing made of porous material to diameter D of intake branch pipe lies within range of optimum values B/D=5.5-7.5. Ratio of thickness b of outer bushing made of porous material to its height B lies within range of optimum values b/B=0.05-0.1, and value of clearance s between outer bushing made of porous material and cup-screen lies within range of optimum value s=(0.05-0.2)xB. Outer cylindrical bushing is made of material based on aluminum-bearing alloys with subsequent filling with titanium hydride or air, density within 0.5 and 0.9 kg/cu.m and the following strength properties: compression strength within 5 and 10 MPa.

EFFECT: increased efficiency of noise silencing.