Additive manufacturing apparatuses including environmental systems and methods of using the same

An additive manufacturing apparatus comprising:

• a process chamber surrounding a print head, a recoat head, and a linear motion stage to which the print head and the recoat head are coupled, wherein the print head and recoat head operate within the process chamber to build a three-dimensional object by depositing a build material and a binder material;
• a first plurality of sensors positioned within the process chamber, wherein the first plurality of sensors comprises at least a temperature sensor and a pressure sensor;
• a particle separation system fluidly coupled to the process chamber to receive a particle-laden stream from the process chamber, wherein the particle separation system separates at least some particles out from the particle-laden stream to produce a reduced-particle stream;
• a filter fluidly coupled to the particle separation system to receive the reduced-particle stream from the particle separation system, wherein the filter removes additional particles from the reduced-particle stream to provide a clean gas stream;
• a blower receiving the clean gas stream;
• a temperature control unit for cooling the clean gas stream;
• a condenser system;
• and
• a second plurality of sensors positioned external to the process chamber and after the particle separation system, the filter, the blower, the temperature control unit, and the condenser system and before the process chamber along a fluid recirculation path, wherein the second plurality of sensors comprises at least a temperature sensor, a pressure sensor, and one or more of a lower explosive limit (LEL) sensor, a humidity sensor, and a vapor sensor;
• wherein the process chamber, the particle separation system, the filter, the blower, the condenser system, and the temperature control unit form a closed loop.

A method of controlling an environment within a process chamber, the method comprising:

• receiving, information regarding a temperature, a pressure, and a vapor content within the process chamber from at least one sensor located within the process chamber;
• removing a particle-laden stream from the process chamber;
• separating particles from the particle-laden stream to provide a clean gas stream;
• adjusting a temperature, a vapor content, or both of the clean gas stream based on the received information to achieve a predetermined temperature, pressure, and vapor content within the process chamber;
• and
• pumping the clean gas stream into the process chamber.