Patent ID: 8197700
Filing Date: 2012-06-12
Classification: B01D

Abstract:
1. A computerized method of sizing a three-phase separator comprising the steps of: (a) providing a computer having a database defining fields, at least a portion of the fields containing available preselected sizes for a plurality of predefined separators, the fields also containing a preselected length to diameter ratio, a minimum required light liquid level for a light liquid phase, and a minimum required heavy liquid level for a heavy liquid phase associated with each of the preselected sizes for the predefined separators, the computer also having memory with instructions stored therein, the instructions including a design conditions calculator to calculate preselected design conditions related to a fluid entering the predefined separator responsive to predetermined values entered by an operator, a separation time calculator to calculate rising time of the light liquid droplets in the heavy liquid and settling time of the heavy liquid droplets in the light liquid responsive to a calculated light liquid holdup volume and a calculated heavy liquid holdup volume that are calculated by a holdup volume calculator, a terminal velocity calculator to calculate the terminal velocity of the vapor responsive to the predetermined values entered by an operator, a required vapor flow area calculator to calculate the required vapor flow area responsive to the terminal velocity of the vapor, and a minimum dimension retriever that retrieves a smallest available length and a smallest available diameter for a separator from the database responsive to length to diameter ratios entered by the operator; (b) entering the predetermined values by an operator, and a range of length to diameter ratios defined by a minimum length to diameter ratio and a maximum length to diameter ratio, the minimum and maximum length to diameter ratios being defined by the operator; (c) calculating the design conditions with the design conditions calculator responsive to the predetermined values entered by the operator, the design conditions including a required light liquid holdup volume, a required light liquid surge volume, a required heavy liquid holdup volume, a required heavy liquid surge volume, and a required total light liquid volume; (d) retrieving from the fields the smallest available minimum diameter and the smallest available minimum length with the minimum dimension retriever responsive to the range of length to diameter ratios entered by the operator; (e) retrieving from the fields the minimum required light liquid level, and the minimum required heavy liquid level responsive to the smallest available minimum length and smallest available minimum diameter determined responsive to the length to diameter ratios; (f) calculating a volume of the heavy liquid and a volume of the light liquid responsive to the length, the diameter, the minimum required light liquid level, and the minimum required heavy liquid level, the volume of the heavy liquid defining a calculated heavy liquid holdup volume and the volume of the light liquid defining a calculated light liquid holdup volume, the heavy liquid holdup and light liquid holdup volumes being responsive to the dimensions of the separator; (g) incrementally increasing the minimum required heavy liquid level and repeating step (f) until the calculated heavy liquid holdup volume is at least as great as the required heavy liquid holdup volume; (h) incrementally increasing the minimum required light liquid level and repeating steps (f)-(g) for the calculated light liquid holdup volume to be at least as great as the required total light liquid volume; (i) calculating the rising time of the light liquid droplets in the heavy liquid and the settling time of the heavy liquid droplets in the light liquid responsive to the calculated light liquid and heavy liquid holdup volumes; (j) incrementally increasing the length of the separator by a predetermined length incremental step; (k) confirming an associated length to diameter ratio based upon the incrementally increased separator length is less than the maximum length to diameter ratio entered by the operator and repeating steps (f)-(j) and replacing the smallest available minimum length with the incrementally increased separator length for the rising time of the light liquid droplets in the heavy liquid to be less than heavy liquid resistance time and the settling time of the heavy liquid droplets in the light liquid to be less than the light liquid residence time; (l) incrementally increasing the diameter of the separator by a predetermined diameter incremental step; (m) confirming the maximum diameter from the database having available sizes for separators is at least as great as the separator diameter based upon the incrementally increased separator diameter and repeating steps (e)-(l) and replacing the smallest available minimum diameter with the incrementally increased separator diameter for the length to diameter ratio to be less than the maximum length to diameter ratio, the computer being operable to provide a prompt to the operator that the separator diameter exceeds the maximum diameter from the database having available sizes for separators; (n) calculating the terminal velocity of the vapor responsive to the predetermined values entered by the operator; (o) calculating the required vapor flow area responsive to the terminal velocity of the vapor; (p) providing a vapor phase height calculator to calculate a calculated vapor phase height responsive to the separator diameter, the heavy liquid level, and the light liquid level; (q) providing a vapor phase area calculator to calculate a calculated vapor phase area responsive to the separator length, the separator diameter, and the calculated vapor phase height; (r) calculating the calculated vapor phase height with the vapor phase height calculator; (s) calculating the calculated vapor phase area with the vapor phase area calculator; (t) incrementally increasing the separator length by the predetermined length incremental step; (u) repeat steps (j)-(t) above for the calculated vapor phase area to be at least as great as the required vapor flow area; (v) incrementally increasing the diameter of the separator by a predetermined diameter incremental step; (w) confirming the maximum diameter from the database having available sizes for separators is at least as great as the separator diameter based upon the incrementally increased separator diameter and repeating steps (e)-(v) and replacing the smallest available minimum diameter with the incrementally increased separator diameter for the length to diameter ratio to be less than the maximum length to diameter ratio, the computer being operable to provide a prompt to the operator that the separator diameter exceeds the maximum diameter from the database having available sizes for separators; and (x) reporting the length and diameter of the separator.