Apparatus and method for handling easily polymerizable substance, apparatus for extracting liquid from apparatus under reduced pressure, and process for producing easily polymerizable substance

An apparatus for handling an easily polymerizable substance, comprising:

• a decompressor for handling under reduced pressure a liquid containing the easily polymerizable substance;
• a liquid extraction pipe for extracting the liquid from said decompressor, said liquid extraction pipe having an upstream end that opens in said decompressor;
• a pump in a mid-section of said liquid extraction pipe;
• a first strainer connected to said liquid extraction pipe on an upstream side of said pump;
• a second strainer connected to said liquid extraction pipe on the upstream side of said pump, said second strainer being in parallel with said first strainer;
• a first valve on an upstream side of said first strainer;
• a second valve on a downstream side of said first strainer;
• a third valve on a upstream side of said second strainer;
• a fourth valve on a downstream side of said second strainer;
• a first exhaust device for exhausting air from a part between said first valve and said second valve;
• a second exhaust device for exhausting air from a part between said third valve and said fourth valve;
• and
• a branch pipe connecting said part between said first and second valves and said part between said third and fourth valves with a part of said liquid extraction pipe on a downstream side of said pump,
• wherein said decompressor comprises a device for distilling under reduced pressure an easily polymerizable polymer selected from the group consisting of acrylic acid, methacrylic acid, and esters thereof.