Vertical Separator with Flush Inlet Nozzles or Inlet Nozzle with 90° Elbow (Gas - Oil)
 
  Process Calculation
                           
                    ( Enter values only in yellow cells)    
  DATA INPUT
                                 
    Gas Standard Volumetric Flow, Qs  =  MMSCFPD API Gravity of Condensate, GsL =  °  
                                 
    Standard Pressure, Ps =  psia Specific Gravity of Gas, GsG  =    
                 
Standard Temperature, Ts =  °F Liquid Flow Rate, QL =  BPD
TsR =  °R
Operating Pressure, Po =  psig Compressibility Factor @ ToR (Z) =
 psia
Operating Temperature, To =  °F Compressibility Factor @ TsR (Zs) =
ToR =  °R
Fluid Retention time (operation), Tr1 =  min With Mesh
Fluid Retention time  alarm high (emergency), Tr2 =  min With Alarms
Fluid Retention time  alarm low (emergency), Tr3 =  min
The velocity of the gas in the outlet nozzle, VGN =  ft/s (Considering Maximum Allowable: 60-90 ft/s)
The condensate exit velocity, VLN =  ft/s (Considering Maximum Allowable: 3 ft/s)
                                 
                               
  CALCULATIONS
                                 
    Specific Gravity, GS =         GS =   141,5                
              °API+131.5                
                                 
              Liquid Density, ρL =    lbs/ft³       ρL = GS x ρwater              
                                 
              Air Density, ρair =    lbs/ft³   ρair =   P x PM                
              R x ToR x Z                
                                 
    Gas density: ρG =    lbs/ft³       ρG = GS x ρair              
                                 
    Condensate Mass Flow: WL =    lbs/s   WL =   QL x ρL x 5.61            
              24x3600            
                                 
    Gas Flow rate, QG =     ft³/s   QG =   Ps x Qs x ToR x Z      
              P x TsR x Zs x 24 x 3600      
                                 
    Gas Mass Flow: WG =    lbs/s        WG = QG x ρG              
                                 
    Relationship WL / WG =                            
                                 
    K =          K = 0.35    if    WL/WG < 0.1      
               K = 0.25    if    0.1 ≤ WL/WG ≤ 1      
               K = 0.20    if    WL/WG > 1      
                                 
    Gas Speed Calculation, VG =    ft/s     VG =   K   x ( ρL - ρG ) ½      
              ρG        
                                 
    Cross Sectional Area Calculation, A =    ft²     A =   QG                
              VG                
                                 
    Vessel Inner Diameter Calculation, Dc =  ft     Dc = ( 4 x A ) ½            
            π              
                                 
    Selected Vessel Inner Diameter, D =    ft                        
                                 
    Definitive Cross Sectional Area, A =    ft²   A =   D² x π                
              4                
                                 
    Liquid Flow Rate Calculation, QL =     ft³/s   QL =   WL                
              ρL                
                                 
    Mixture density, ρMIX =    lbs/ft³   ρMIX =   WL + WG                
              QL + QG                
                                 
    Speed in Nozzle, for the mixture VM =    ft/s   VMIX = 80                
     (Maximum Allowable: 30 ft/s)  ft/s   (ρMIX)¹ʹ²                
                                 
    Inlet Nozzle Diameter, dI =    in.     dI = ( 4(QL+QG) ) ½            
    Selected Inlet Nozzle Diameter, dI  =  in.   π x VMIX              
                                 
    Height between the inlet nozzle’s top                            
    and the drum’s top tangent line, h1 =    ft   Height between the inlet nozzle’s top and the drum’s top  
            tangent line, hnoozle-tang  (h1):          
            - Perpendicular entry and no mesh: 920 mm (Approx 3 ft) or  
            0.5D, whichever is greater.            
            - Perpendicular entry and with a mesh: 400 mm (16 in) or  
            0.15D, whichever is greater + 150 mm (6 in) + 610 mm (24 in)  
            or 0.5D, whichever is greater.            
                                 
    Fluid Retention time (operation), Tr1 =    min.   For Crude ºAPI  ≥   40  → Tr1 = 1½ min    
            For Crude 25  <  ºAPI  <   40  →  Tr1 = 3 min    
            For Crude ºAPI  ≤  25  →  Tr1 = 5 min      
                                 
    Fluid Retention Volume (operation), Vr1 =   ft³   Vr1 = 60 x QL x Tr1              
                                 
    Height the liquid in the vessel (operation), h4 =    ft   h4 =   Vr1                
              A                
                                 
    Height the liquid in the vessel hdp-HHLL, h2 =    ft   In the case of vertical drums with perpendicular entry:  
    Consideging minimun of 0.3D, hdp-HHLL, h2 =    ft   hNAAL-boq = dI  
                                 
    Fluid Retention Volume alarm high (emergency), Vr2 =     ft³   Vr2 = 60 x QL x Tr2              
                                 
    Height the liquid in the vessel alarm high (emergency), h3 =    ft   h3 =   Vr2                
              A                
                                 
    Fluid Retention Volume alarm low (emergency), Vr3 =     ft³   Vr3 = 60 x QL x Tr3              
                                 
    Height the liquid in the vessel alarm low (emergency), h5 =   ft   h5 =   Vr3                
              A                
                                 
    Height the liquid in the vessel hLLLL-botton, h6 =      ft The minimum distance (h6) from the low-low level of liquid  
            LLLL to the liquid outlet nozzle is 9 in. minimum.    
                                 
    Vessel Length, L =    ft    L = h1 + dp + h2 + h3 + h4 + h5 + h6      
                                 
    Gas Outlet Nozzle Diameter, dG =    in.   dG = ( 4QG ) ½            
    Selected Gas Outlet Nozzle Diameter, dG  =    in.   π x VGN              
                                 
    Liquid Outlet Nozzle Diameter, dL =    in.   dL = ( 4QL ) ½            
    Selected Liquid Outlet Nozzle Diameter, dL  =    in.   π x VLN              
                                 
    Check  
    Estimate the total length seam to seam of the vessel considering economic relations L/D of the vessel with the margin from 2.5 to 6.    
    Verify that the final computed L / D ratio falls in this range. If L is too low, arbitrarily provide more time of liquid retention if L is too high,    
    follow a horizontal design. Whenever possible, the lengths and diameters should be adjusted to produce sizes that match the standard    
    designs of the equipment suppliers.                            
                                 
    LMIN =  ft   LMIN = 2.5 x D                
    LMAX =  ft   LMAX = 6 x D                
    Vessel Length, L =    ft              
                                 
                                 
                       
Vertical Separator with Flush Inlet Nozzles or Inlet nozzle with 90° Elbow (Gas - Oil)
  Schematic Drawing  
 
    Imagen que contiene mapa, texto Descripción generada con confianza muy alta                    
                         
                         
                         
                         
                         
                         
                         
                         
                         
                         
                         
                         
                         
                         
                         
                         
                         
                         
                         
                         
                         
                         
                         
                         
                         
                         
                         
                         
                         
                         
                         
    DIMENSIONS    
                         
    Vessel Inner Diameter Calculation, D =    ft          
    Vessel Length, L tan-tan =    ft          
    Selected Inlet Nozzle Diameter, dI  =  in.          
    Selected Gas Outlet Nozzle Diameter, dG  =    in.          
    Selected Liquid Outlet Nozzle Diameter, dL  =    in.          
Height between the inlet nozzle’s top
    and the drum’s top tangent line, h1 =    ft          
                         
    Height the liquid in the vessel hdp-HHLL, h2 =  ft          
                         
    Height the liquid in the vessel (emergency), h3 =   ft          
                         
    Height the liquid in the vessel (operation), h4 =   ft          
                         
    Height the liquid in the vessel (emergency), h5 =   ft          
                         
    Height the liquid in the vessel hLLLL-botton, h6 =      ft          
                         
NOTES:
    1. If applicable: five minutes of liquid flow between HHLL and HLL (same for LLLL and LLL). If it does not apply, there is only HLL and LLL.    
    2. Height between HLL and LLL depends on the retention minutes based on the flow of liquid feed.    
    3. The minimum distance from the low-low level of liquid LLLL to the liquid outlet nozzle is 9 in.    
    4. Set the height from the inlet nozzle and the Mesh or the upper tangent line (hnozzle-Mesh or hnozzle-tan).
- For the case of vertical drums with flush inlet nozzles or Inlet nozzle with 90° elbow and without mesh, use a minimum of 3.0 feet or 0.5 times the diameter of the drum (whichever is greater), between the inlet nozzle and the upper tangent line (hnozzle-tan).
- For the case of vertical drums with flush inlet nozzles or Inlet nozzle with 90° elbow and with mesh, use a minimum of  24 in. or 0.5 times the diameter of the drum (whichever is greater), between the inlet nozzle and the bottom of the mesh (hnozzle-Mesh) + 6 in. for the mesh + 16 in. or 0.15D, whichever is greater between the top of the mesh and the upper tangent line (hMesh-tan). 		 
    5. The height will depend on the type of entry as follows:
- In the case of vertical drums with flush inlet nozzles or Inlet nozzle with 90° elbow: h2 = dI 		   
                         
                                           
    Discussion and References  
    Vertical Separator with Flush Inlet Nozzles or Inlet nozzle with 90°  Elbow (Gas - Oil)  
    Process Calculation  
    Reference Books  
  - 1. Campbell, John M., “Gas Conditioning and Processing” (1976).    
  - 2. Kerns, G.D., “New Charts Speed Drum Sizing", HYDRO. PROC. 39 (7). (July, 1960).
    
  - 3. Lobdell, W. R., y L. M. Ayers, “Separators Cut Weight, Cost for Gas–Production Equipment,  (March 10, 1975).
    
  - 4. Perry, Robert H., y Cecil H. Chilton, “Chemical Engineers’ Handbook,” Fifth
Edition, McGraw–Hill, (1973). 		   
  - 5. Watkins, R.N., “Sizing Separators and Accumulators”, HYDRO. PROC. 46(11), (Nov. 1967).
    
  - 6. Svrcek. W.Y, Monmery, W.D., “Design two phase separators within the right limits”, Chemical Engineering Progress, Octubre 1993.    
  - 7. Gas Processor Suppliers Association (GPSA) Engineering Data Book, Vol 1, Section 7 “Separators and Filter”. Tenth Edition, 1987.    
       
    Density Calculation of Condensate: ρL (lbs/ft³)        
    Specific Gravity:            
        GS = 141,5                        
      °API+131.5                        
    Liquid Density:            
    ρL = GS x ρwater                            
    Where:              
    ρwater = 62.4 lb/ft3              
                                         
    Density Gas Calculation: ρG (lbs/ft³)        
    Air Density: ρAIR @ Operating Temperature, °F            
      ρair =   PxPM                            
        RxTxZ                            
    Where:              
    P = absolute pressure (PSIA)              
    P = Operating Pressure, Po + 14.7  (PSIA)              
    MW = Molecular Weight - air (28.97 lbm / lbmol)        
    R = universal gas constant (10.73 lbm/lbmol°R)          
    T = absolute temperature (°R)              
    T = To + 460 °R              
    Z = compressibility factor              
                                         
     Gas density: ρG (lbs/ft³)            
      ρG= GS x ρair                          
                                         
    Condensate Mass Flow: WL (lbs/s)            
    WL =   QL x ρL x 5.61                      
      24x3600                    
    Where:                  
    QL = Liquid Flow Rate, BPD                  
    ρL = Liquid Density, lbs/ft³                  
                                         
    Gas Flow Rate, QG (ft³/s)            
      QG =   Ps x Qs x ToR x Z                  
        P x TsR x Zs x 24 x 3600                  
    Where:              
    Ps = 14.7 PSIA              
    Qs = Gas Standard Volumetric Flow, MMSCFPD          
    ToR = To + 460, °R              
    Z = compressibility factor @ ToR              
    P = Po +14.7, PSIA              
    TsR = Ts + 460, °R              
    Zs = compressibility factor @ TsR              
                                         
    Gas Mass Flow: WG, (lbs/s)            
      WG = QG x rG                          
    Where:                        
    QG = Gas Flow Rate, ft³/s                  
    ρG = Gas Density, lbs/ft³                  
                                         
    Relationship WL / WG              
           K = 0,35 if   WL < 0,1              
        WG              
           K = 0,25 if   0,1 ≤ WL ≤ 1          
        WG          
           K = 0,20 if   WL > 1              
        WG            
 
                                         
    Gas Speed Calculation, VG (ft/s)            
      VG = K   x ( ρL - ρG ) ½                
 
    ρG                  
                                         
    Cross Sectional Area Calculation, A (ft²)            
      A =   QG                              
        VG                              
                                         
    Vessel Inner Diameter Calculation, D (ft)            
      D = ( 4 x A ) ½                        
      π                          
                                         
    Definitive Cross Sectional Area, A (ft²)            
      A = D² x π                            
      4                            
                                         
    Liquid Flow Rate Calculation, QL (ft/s)          
 
      QL =   WL                              
        ΡL                            
                                       
    Mixture density, ρMIX            
      ρMIX =   WL + WG                        
 
QL + QG
                                       
    Allowable Speed in Nozzle, for the mixture (Maximum Allowable: 30 ft/s)            
    VMIX = 80                          
    (ρMIX)¹ʹ²                          
                                         
    Inlet Nozzle Diameter, dI            
      dI = ( 4 (QL+QG) ) ½                      
      π x VMIX                        
                                         
    Vessel Length, L            
      LMIN = 2.5 x D                            
      LMAX = 6 x D                            
    Height between the inlet nozzle’s top and the drum’s top tangent line, hnoozle-tang  (h1)
- With tangential entry: 1200 mm (Approx 4 fts)
- No tangential entry and no mesh: 920 mm (Approx 3 fts) or 0.5D, whichever is greater.
- No tangential entry and with a mesh: 400 mm (16 in) or 0.15D, whichever is greater + 150 mm (6 in) + 610 mm (24 in) or 0.5D, whichever is greater. 		   
    Height between the inlet noozle’s bottom and HHLL: (h2)
- In the case of vertical drums with tangential entry: hNAAL-boq = DVESSEL + 150mm (6 ")
- In the case of vertical drums without tangential entry: hNAAL-boq = dI 		   
    Height between HLL and LLL (h4) depends on the retention minutes based on the flow of liquid feed.
The liquid operation retention volume, between the HLL and the LLL (h4), is obtained by multiplying the liquid feed flow by the retention time: 		   
      Vr1 = 60 x QL x Tr1   and   h4 = Vr1/A            
      Retention Time, Tr1        
      For Crude ºAPI  ≥   40  ®  Tr1 = 1½ min          
      For Crude 25  <  ºAPI  <   40  ®  Tr1 = 3 min          
      For Crude ºAPI  ≤  25  ®  Tr1 = 5 min          
                                         
    The liquid retention volume per operator response time when an alarm is triggered (either high or low), between the HHLL and the LLLL, is obtained by multiplying the liquid feed flow by the assumed response time, (Tr2) which is estimated at 5 min (300 s), (Tr3) from HLL to HHLL, and 5 min more (300 s), from LLL to LLLL:    
      Vr2 = 60 x QL x Tr2   and   h3 = Vr2/A            
      Vr3 = 60 x QL x Tr3   and   h5 = Vr3/A            
    In the case that there are no switches and/or alarms of LLLL and HHLL, this additional volume is null.    
    The minimum distance from the low-low level of liquid LLLL to the liquid outlet nozzle (h6) is 230 mm minimum (9 in).    
    Vessel Length, L                              
      L = h1 + dp + h2 + h3 + h4 + h5 + h6                
    Gas Outlet Nozzle Diameter, dG            
    Considering VGN = 60-90 ft/s            
      dG = ( 4QG ) ½                        
      π x VGN                          
                                         
    Liquid Outlet Nozzle Diameter, dL            
    Considering VLN = 3 ft/s            
      dL = ( 4QL ) ½                        
π x VLN