The invention provides a horizontal flash tank for a centrifugal unit. The horizontal flash tank comprises a head, a shell body, a liquid inlet
pipe, a liquid outlet, a liquid spraying liquid return opening and an
oil cooling liquid return opening. The liquid inlet
pipe and the head are welded deep in the inside of the flash tank, an end opening of the liquid inlet
pipe is upward, the end portion of the liquid inlet pipe is drilled, and the end opening of the liquid inlet pipe is welded through a plug plate. The liquid spraying liquid return opening and the
oil cooling liquid return opening are welded to the shell body, and an opening portion is provided with an
impact-resistant baffle. A baffle, a certain distance from the
impact-resistant baffle, is welded close to the right side of the
impact-resistant baffle. The right side of the baffle is provided with a fixing gird plate and a first-level filtering screen which are welded to the shell body. An air absorbing baffle is arranged under an air outlet and welded to the shell body. A second-level filtering demisting screen
assembly is arranged under the air absorbing baffle, two sides of the second-level filtering demisting screen
assembly are provided with end plates, and the end plates and the second-level filtering demisting screen
assembly are welded to the shell body. The horizontal flash tank can effectively lower
noise and severe fluctuation of a liquid face generated after high-speed liquid refrigerants enters the flash tank, and eliminate the phenomenon that liquid exists in gas.