Filter capable of automatically cutting off gas flow

A filter capable of automatically cutting off gas flow, comprising:

• a housing with a cavity, the housing being provided with an inlet end and an outlet end;
• a filter element disposed in the cavity, wherein the filter element is provided with a first chamber formed by being enclosed by a filter media, a second chamber communicated with the outlet end is formed between the filter element and the housing, and a flow channel is disposed between the first chamber and the inlet end;
• and
• a blocking mechanism disposed in the flow channel;
• wherein the filter element is provided with an unblocking member, and the blocking mechanism has an unblocking state in which the blocking mechanism is cooperated with the unblocking member to allow a gas flow to flow out of the flow channel, and a blocking state in which the blocking mechanism prevents the gas flow from flowing out of the flow channel;
• wherein the filter comprises an elastic member that exerts an elastic restoring force on the filter element, wherein the elastic restoring force exerted by the elastic member on the filter element is capable of preventing the filter element from moving downward relative to the blocking mechanism;
• and
• wherein a relationship between a final deformation amount of the elastic member and a pressure drop of the filter element satisfies the following formula:
• L
• s
• =
• πΔ
• ⁢
• p
• s
• k
• [
• r
• 1
• 2
• +
• 2
• r
• 1
• -
• r
• 2
• ⁢
• (
• r
• 2
• 3
• -
• r
• 1
• 3
• 3
• -
• r
• 2
• 2
• -
• r
• 1
• 2
• 2
• )
• ]
• ,
• where Ls represents a final deformation amount of the elastic member, in unit of mm;
• Δps represents a pressure drop of filter element, in unit of Pa;
• k represents an elastic coefficient;
• r1 represents a radius of the first chamber, in unit of mm;
• and r2 represents a radius of the filter element.