Exhaust pipe having means for preventing deposition of a reaction by-product and method for preventing deposition of a reaction by-product

Abstract

An exhaust pipe () includes an inner cylinder () having an exhaust gas passage (') formed therein, an outer cylinder provided outside the inner cylinder with a gap () being formed therebetween and a heating device () attached to the inner cylinder. The gap () is communicated with the exhaust gas passage (′). When a gas is discharged from the reaction vacuum chamber, a vacuum is created not only in the exhaust gas passage (′) but also in the gap (). Therefore, release of heat from the heating device to the outside can be suppressed. Consequently, the inner cylinder () can be efficiently heated to a sufficiently high temperature, thus preventing deposition and accumulation of a substance contained in the discharged gas on the inner surface of the inner cylinder (). The deposition and accumulation of such a substance can also be prevented by forming a gas flow layer () of, for example, an inert gas, along the inner surface of the inner cylinder (