RESEARCH ARTICLE Inﬂuence of Oriﬁce Position Deviations on Distribution Performance of Gravity-Type Liquid Distributor Analyzed Through Mathematical Pathway Jinsheng Sun 1 • Zhiwei Zhang 1 • Chengtian Cui 1 • Tianpei Li 1 • Sheng Fu 1 Received: 7 September 2016 / Revised: 30 November 2016 / Accepted: 10 March 2017 Ó Tianjin University and Springer-Verlag GmbH Germany 2017 Abstract The distribution performance of the gravity-type liquid distributor (GTLD) signiﬁcantly affects column operation efﬁciency and the consequent product quality. In industrial settings, maldistribution is normally considered to be caused by vertical positional or coplanarity errors stemming from deﬂections associated with manufacture and installation, or even by excessive weight. The lack of estimation protocols or standards impedes the description of this error, which inﬂuences the corresponding outﬂow rates. Given this situation, the paper proposes a lumped parameter, oriﬁce position deviation (OPD), to facilitate the calculation of the relative discharge rate error (RDRE) based on a formula derivation, which allows the systematic analysis of the inﬂuence of a single oriﬁce or weir OPD. The paper introduces a sensitivity factor K as a concise and uniﬁed expression in theoretical RDREs for calibrating the inﬂuence of OPD on the RDREs of geometrically different oriﬁces and weirs. With respect to the GTLD, a larger K indicates the need for more strict OPD requirements. The paper veriﬁes that the extent of GTLD outﬂow nonuni- formity is associated with diverging tendencies regarding its morphology, especially in the oriﬁce and weir, which can be determined using our proposed procedures. Keywords Liquid distributor  Installation  Oriﬁce position deviation  Relative discharge rate error  Sensitivity factor Introduction The liquid distributor, a key column internally installed at the top of or in between packed beds, redistributes returning liquid, reﬂux, and (or) feeding stream(s) between the packed beds [1, 2], as shown in Fig. 1. With respect to their hydrodynamics, liquid distributors can be classiﬁed according to the driver of the liquid ﬂow as either gravity or pressure types. In terms of their structural appearance, these distributors include tube, groove, spray, and disc types. Their ﬂuid outﬂow patterns include oriﬁces, weirs, and nozzle types [3]. The performance of liquid distributors has been studied both experimentally and theoretically for over 80 years [4]. The product quality, process safety, and operation efﬁ- ciency of a distillation column largely depend on the dis- tribution quality of the liquid distributor. A uniform liquid distribution has three qualiﬁcation standards: sufﬁcient spraying point density, geometrically uniform distribution of the spraying points, and uniformity of discharge by the spraying points [5]. Levelness and planarity strongly affect the uniformity of the discharge rate of the spraying points and the distribution performance of gravity-type liquid distributors (GTLDs), as opposed to their pressure-type counterparts [5]. Fractionation Research Inc. (FRI) has investigated this inﬂuence by measuring the theoretical discharge ﬂow rate, based on both engineering experience and experimentation [2, 5, 6]. Based on the work of Kunesh et al. [4], Ahmad and Kunesh [7] found maldistribution to worsen with increasing unlevelness, which is more Electronic supplementary material The online version of this article (doi:10.1007/s12209-017-0078-6) contains supplementary material, which is available to authorized users. & Jinsheng Sun jssun2006@vip.163.com 1 School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China 123 Trans. Tianjin Univ. DOI 10.1007/s12209-017-0078-6