Fan bypass system for contamination control

An image forming device, comprising:

• an image forming section that produces contamination;
• a contamination control apparatus for controlling the contamination, the contamination control apparatus having
• an air mover located in the image forming device, the air mover having an air input and an air output, the air mover configured to move non-compressed air from the air input to the air output;
• a first duct within the image forming device having a first end and a second end, the first end having an opening positioned to receive non-contaminated air that is not contaminated with the contamination, and the second end being fluidly connected to the air input of the air mover such that the air input receives the non-contaminated air from the first duct;
• an exhaust duct within the image forming device having a first end and a second end, the first end being fluidly connected to the air output of the air mover such that the first end of the exhaust duct receives only the non-compressed non-contaminated air from the air output, the exhaust duct being split into a plurality of non-contaminated air exhaust ducts, each of the plurality of non-contaminated air exhaust ducts having a first portion with a first cross section and a second portion having a second cross section, the second cross section being smaller than the first cross section to increase the velocity of the non-contaminated air within;
• and
• a second duct within the image forming device having a first end and a second end, the first end being positioned such that contaminated air from the image forming section of the image forming device is drawn into the first end of the second duct, and the second end of the second duct being fluidly connected to each of the plurality of non-contaminated air exhaust ducts at a position downstream of the air output of the air mover and upstream of the second end of the exhaust duct such that each of the plurality of non-contaminated air exhaust ducts outputting only the non-contaminated air from the air output to the connection with the second duct,
• the second portion of each non-contaminated air exhaust ducts having the smallest cross section of the respective non-contaminate air exhaust duct, the second cross section at the smallest cross section expanding only at the fluid connection with the second end of the second duct and at the fluid connection with another one of the plurality of non-contaminated air exhaust ducts,
• wherein the non-compressed non-contaminated air from the plurality of non-contaminated air exhaust ducts and the contaminated air are mixed together in the exhaust duct downstream of the air output of the air mover and upstream of the second end of the exhaust duct to form a mixed air, and
• the mixed air is exhausted from the second end of the exhaust duct.

A method of controlling contamination in an image forming device, the method comprising:

• moving with an air mover within the image forming device non-contaminated air that is not contaminated with the contamination from inside the image forming device, the air mover configured to move non-compressed air from an air input to an air output of the air mover;
• moving the non-contaminated air through a first duct within the image forming device having a first end and a second end, the first end having an opening positioned to receive the non-contaminated air, and the second end being fluidly connected to the air input of the air mover such that the air input receives the non-contaminated air from the first duct;
• moving the non-compressed non-contaminated air through an exhaust within the image forming device duct having a first end and a second end, the first end being fluidly connected to the air output of the air mover such that the first end of the exhaust duct receives only the non-compressed non-contaminated air from the air output, the exhaust duct being split into a plurality of non-contaminated air exhaust ducts, each of the plurality of non-contaminated air exhaust ducts having a first portion with a first cross section and a second portion having a second cross section, the second cross section being smaller than the first cross section to increase the velocity of the non-contaminated air within, wherein moving the non-compressed non-contaminated air through the exhaust duct includes moving the non-compressed non-contaminated air through the plurality of non-contaminated air exhaust ducts;
• and
• moving contaminated air from a contamination producing element of the image forming device though a second duct within the image forming device having a first end and a second end, the first end being positioned such that the contaminated air is drawn into the first end of the second duct, and the second end of the second duct being fluidly connected to each of the plurality of non-contaminated air exhaust ducts at a position downstream of the air output of the air mover and upstream of the second end of the exhaust duct such that each of the plurality of non-contaminated air exhaust ducts outputting only the non-contaminated air from the air output to the connection with the second duct,
• the second portion of each non-contaminated air exhaust ducts having the smallest cross section of the respective non-contaminate air exhaust duct, the second cross section at the smallest cross section expanding only at the fluid connection with the second end of the second duct and at the fluid connection with another one of the plurality of non-contaminated air exhaust ducts,
• wherein the non-compressed non-contaminated air from the plurality of non-contaminated air exhaust ducts and the contaminated air are mixed together in the exhaust duct downstream of the air output of the air mover and upstream of the second end of the exhaust duct to form a mixed air,
• the mixed air is exhausted from the second end of the exhaust duct, and
• a flow of the non-compressed non-contaminated air in the exhaust duct creates a negative pressure in the second duct, the negative pressure causing the contaminated air to flow through the second duct.