Dividing wall column

The invention relates to a dividing wall column (100), a vertical partition plate is arranged in the dividing wall column, a pre-fractionation section (1) and a main column section (3) are formed on the two sides of the vertical partition plate respectively, and the dividing wall column (100) is provided with a first feeding pipeline (S1) connected with the pre-fractionation section (1) and a first side extraction pipeline (S3) connected with the main column section (3). The dividing wall column (100) is provided with a first switching device (V3) capable of connecting or disconnecting the first side extraction pipeline (S3). 本发明涉及一种隔壁塔(100)，该隔壁塔内部布置有垂直隔板，该垂直隔板的两侧分别形成预分馏段(1)和主塔段(3)，该隔壁塔(100)具有与所述预分馏段(1)相连的第一供料管线(S1)和与所述主塔段(3)相连的第一侧采管线(S3)，其特征在于，所述隔壁塔(100)具有能够接通或断开所述第一侧采管线(S3)的第一开关装置(V3)。