Abstract: [Problem to be Solved] To enhance the performance for separation of oil mist from blow-by gas. [Solution] A filter element 13 which is to be attached to an oil separator unit 3 includes a core 31. This core is a double tube having an internal cylindrical member 34 and an external cylindrical member 35, and a space between the internal cylindrical member and the external cylindrical member is used as a separation chamber 36. An injection hole 39 for injecting blow-by gas while increasing its flow velocity is provided in the internal cylindrical member. A surface which is an inner wall surface of the external cylindrical member and which faces the injection hole is a spraying surface onto which the blow-by gas injected from the injection hole is sprayed. Moreover, an opening for oil discharge from which oil OL condensed on the spraying surface is discharged, and an opening for discharge from which the blow-by gas from which oil mist has been separated is discharged are provided in the core.

Abstract: [Problem to be Solved] To enhance the performance for separation of oil mist from blow-by gas. [Solution] A filter element 13 which is to be attached to an oil separator unit 3 includes a core 31. This core is a double tube having an internal cylindrical member 34 and an external cylindrical member 35, and a space between the internal cylindrical member and the external cylindrical member is used as a separation chamber 36. An injection hole 39 for injecting blow-by gas while increasing its flow velocity is provided in the internal cylindrical member. A surface which is an inner wall surface of the external cylindrical member and which faces the injection hole is a spraying surface onto which the blow-by gas injected from the injection hole is sprayed. Moreover, an opening for oil discharge from which oil OL condensed on the spraying surface is discharged, and an opening for discharge from which the blow-by gas from which oil mist has been separated is discharged are provided in the core.