# US 2019/0314849 A1 · Passive Filter for Aerosol Printing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0314849 A1 - Document ID: US20190314849A1 - Status: Published application - Kind: A1 - Application number: 16/285,338 - Filed: 2019-02-26 - Published: 2019-10-17 - Earliest claimed: 2018-04-11 - Assignees: Government of the United States as Represented by the Secretary of the Air Force - Applicants: Government of the United States as represented by the Secretary of the Air Force - Inventors: Michael F. Durstock; James R. Deneault - Web page: https://patentgrep.com/patent/US20190314849A1 ## CPC - B01J 13/0095: {Preparation of aerosols} - B05B 15/40: Filters located upstream of the spraying outlets - B05B 1/34: designed to influence the nature of flow of the liquid or other fluent material, e.g. to produce swirl (designed to control volume of flow B05B1/30) - B05B 7/0012: {Apparatus for achieving spraying before discharge from the apparatus} - B05B 15/50: Arrangements for cleaning; Arrangements for preventing deposits, drying-out or blockage; Arrangements for detecting improper discharge caused by the presence of foreign matter - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - B05B: SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES (spray-mixers with nozzles B01F25/72; processes for applying liquids or other fluent materials to surfaces by spraying B05D) ## Abstract A passive filter for an aerosol printing system. The passive filter includes a housing having a fluid inlet port at a first end and a fluid outlet port at a second end, the fluid inlet and outlet ports being coaxial. A chamber is disposed within the housing and has a ceiling, a base, at least one wall between the ceiling and the base, a chamber entrance in the ceiling, and a chamber exit. The chamber entrance and exit being coaxial to the fluid inlet and outlet ports. The chamber exit is disposed within chamber between the chamber entrance and the base and defining a circumferential trough about the chamber exit. ## Claims ### Claim 1 A passive filter for a confluent aerosol printing system, the passive filter comprising: a housing having a fluid inlet port at a first end and a fluid outlet port at a second end, the fluid inlet and outlet ports being coaxial; a chamber disposed within the housing and having a ceiling, a base, at least one wall between the ceiling and the base, a chamber entrance in the ceiling, and a chamber exit, the chamber entrance and exit being coaxial to the fluid inlet and outlet ports; and wherein the chamber exit is disposed within chamber between the chamber entrance and the base and defining a circumferential trough about the chamber exit. ### Claim 2 (depends on 1) The passive filter of claim 1, wherein a diameter of the chamber exit is equal to or less than a diameter of the chamber entrance. ### Claim 3 (depends on 1) The passive filter of claim 1, wherein an angular wall extends between the chamber exit and the base of the chamber and the trough is formed between the angular wall and the at least one wall of the chamber. ### Claim 4 (depends on 1) The passive filter of claim 1, wherein a diameter of the chamber is greater than a diameter of the chamber entrance. ### Claim 5 (depends on 4) The passive filter of claim 4, wherein expansion of an aerosol entering the chamber from the chamber entrance filters the aerosol. ### Claim 6 (depends on 1) The passive filter of claim 1, wherein the fluid inlet port is configured to be operably coupled to an aerosol chamber. ### Claim 7 (depends on 1) The passive filter of claim 1, wherein the fluid outlet port is configured to be operably coupled to a print head. ### Claim 8 (depends on 1) The passive filter of claim 1, wherein the housing includes a first housing portion including the inlet port and the chamber entrance and a second housing portion including the outlet port and the chamber exit, the first housing portion and the second housing portion configured to be removably connected for forming the filter chamber. ### Claim 9 A passive filter for a confluent aerosol printing system, the passive filter comprising: a housing having a fluid inlet port at a first end and a fluid outlet port at a second end, the fluid inlet and outlet ports being coaxial; a first chamber disposed within the housing and having a first ceiling, a first base, at least one wall between the first ceiling and the first base, a first chamber entrance in the first ceiling, and a first chamber exit, the first chamber entrance and exit being coaxial to the fluid inlet and outlet ports, wherein the first chamber exit is disposed within first chamber between the first chamber entrance and the first base and defining a first circumferential trough about the first chamber exit; and a second chamber disposed within the housing between the first chamber and the fluid outlet port, the second chamber having a second ceiling, a second base, at least one wall between the second ceiling and the second base, a second chamber entrance in the second ceiling, and a second chamber exit, the second chamber entrance and exit being coaxial to the fluid inlet and outlet ports, wherein the second chamber exit is disposed within second chamber between the second chamber entrance and the second base and defining a second circumferential trough about the second chamber exit. ### Claim 10 (depends on 9) The passive filter of claim 9, wherein a diameter of the first chamber exit is equal to or less than a diameter of the first chamber entrance. ### Claim 11 (depends on 9) The passive filter of claim 9, wherein a diameter of the second chamber exit is equal to or less than a diameter of the second chamber entrance. ### Claim 12 (depends on 9) The passive filter of claim 9, wherein an angular wall extends between the first chamber exit and the first base of the first chamber and the first trough is formed between the angular wall and the at least one wall of the first chamber. ### Claim 13 (depends on 9) The passive filter of claim 9, wherein an angular wall extends between the second chamber exit and the second base of the second chamber and the second trough is formed between the angular wall and the at least one wall of the second chamber. ### Claim 14 (depends on 9) The passive filter of claim 9, wherein a diameter of the first chamber is greater than a diameter of the first chamber entrance. ### Claim 15 (depends on 9) The passive filter of claim 9, wherein a diameter of the second chamber is greater than a diameter of the second chamber entrance. ### Claim 16 (depends on 9) The passive filter of claim 9, wherein expansion of an aerosol entering the first chamber from the first chamber entrance filters the aerosol. ### Claim 17 (depends on 16) The passive filter of claim 16, wherein expansion of the aerosol entering the second chamber from the second chamber entrance further filters the aerosol. ### Claim 18 (depends on 9) The passive filter of claim 9, wherein the fluid inlet port is configured to be operably coupled to an aerosol chamber. ### Claim 19 (depends on 9) The passive filter of claim 9, wherein the fluid outlet port is configured to be operably coupled to a print head. ### Claim at position 20 20-31. (canceled)