The present invention provides a structure that improves sound absorption coefficient. The present invention provides a structure comprising: a foam resin layer formed of a foam material having a foaming ratio of 1.1 to 8 times; and a sound absorbing layer formed of a foam material having a foaming ratio of 10 to 30 times, the sound absorbing layer laminated on the foam resin layer.

The present invention provides a structure that improves sound absorption coefficient. The present invention provides a structure comprising: a foam resin layer formed of a foam material having a foaming ratio of 1.1 to 8 times; and a sound absorbing layer formed of a foam material having a foaming ratio of 10 to 30 times, the sound absorbing layer laminated on the foam resin layer.

Disclosed is a muffler for a water-cooled chiller or air-cooled of a vapor-compression or absorption refrigeration system, the muffler having: an upstream case (110) having a fluid inlet (120); a downstream case (115) connected to the upstream case at a downstream end of the upstream case, the downstream case having a fluid outlet (125); the upstream case having a plurality of axially adjacent outer muffler rings (145) and a plurality of axially adjacent inner muffler rings (155), the outer muffler rings being axially coextensive and a radially exterior to the inner muffler rings and defining a fluid inlet passage (140) therebetween, wherein the outer muffler rings and inner muffler rings are a metal mesh material.

Disclosed is a muffler for a water-cooled chiller or air-cooled of a vapor-compression or absorption refrigeration system, the muffler having: an upstream case (110) having a fluid inlet (120); a downstream case (115) connected to the upstream case at a downstream end of the upstream case, the downstream case having a fluid outlet (125); the upstream case having a plurality of axially adjacent outer muffler rings (145) and a plurality of axially adjacent inner muffler rings (155), the outer muffler rings being axially coextensive and a radially exterior to the inner muffler rings and defining a fluid inlet passage (140) therebetween, wherein the outer muffler rings and inner muffler rings are a metal mesh material.

A duct includes a foam-filled honeycomb core structure having a tubular shape. The duct further includes an air-impermeable duct wall coupled to an exterior surface of the foam-filled honeycomb core structure.

A duct includes a foam-filled honeycomb core structure having a tubular shape. The duct further includes an air-impermeable duct wall coupled to an exterior surface of the foam-filled honeycomb core structure.

Disclosed is a muffler for a water-cooled chiller or air-cooled of a vapor-compression or absorption refrigeration system, the muffler having: an upstream case having a fluid inlet; a downstream case connected to the upstream case at a downstream end of the upstream case, the downstream case having a fluid outlet; the upstream case having a plurality of axially adjacent outer muffler rings and a plurality of axially adjacent inner muffler rings, the outer muffler rings being axially coextensive and a radially exterior to the inner muffler rings and defining a fluid inlet passage therebetween, wherein the outer muffler rings and inner muffler rings are a metal mesh material.

Disclosed is a muffler for a water-cooled chiller or air-cooled of a vapor-compression or absorption refrigeration system, the muffler having: an upstream case having a fluid inlet; a downstream case connected to the upstream case at a downstream end of the upstream case, the downstream case having a fluid outlet; the upstream case having a plurality of axially adjacent outer muffler rings and a plurality of axially adjacent inner muffler rings, the outer muffler rings being axially coextensive and a radially exterior to the inner muffler rings and defining a fluid inlet passage therebetween, wherein the outer muffler rings and inner muffler rings are a metal mesh material.

Disclosed is a muffler for a water-cooled chiller or air-cooled of a vapor-compression or absorption refrigeration system, the muffler having: an upstream case (110) having a fluid inlet (120); a downstream case (115) connected to the upstream case at a downstream end of the upstream case, the downstream case having a fluid outlet (125); the upstream case having a plurality of axially adjacent outer muffler rings (145) and a plurality of axially adjacent inner muffler rings (155), the outer muffler rings being axially coextensive and a radially exterior to the inner muffler rings and defining a fluid inlet passage (140) therebetween, wherein the outer muffler rings and inner muffler rings are a metal mesh material.

A duct includes a foam-filled honeycomb core structure having a tubular shape. The duct further includes an air-impermeable duct wall coupled to an exterior surface of the foam-filled honeycomb core structure.