SEPARATOR Design of Equipments Process Chemical Engineering 2012 – B Class Second Group 1. Winda Rahma Tiara(03121403018) 2. Ana Barika(03121403038) 3.

SEPARATOR Design of Equipments Process

Chemical Engineering 2012 – B Class

Second Group

1. Winda Rahma Tiara

(03121403018)

2. Ana Barika

(03121403038)

3. Abiyyu Ahmad

(03121403056)

Terminology / Definitions of Separators

Separator is a pressure vessel to separate the fluid mixture (liquid or gas) based on differences in density;1. Separator is one of the major

equipment that have an important role in the operation of oil refineries and natural gas;

2. Separator is used to separate production fluids from the production wells into two or three phases. 

The Principle of Design

Separator works on the principle of separation by specific gravity / density where required vessel volume and specific retention time, so that existing phases can be separated . Determination of the design of the separator is an important thing that will determine the production capacity of all existing facilities.

A. Based on the Phase Separation, Separator can devided into:1. Two Phase Separator

To seperate the liquid phase and gas phase; 2. Three Phase Separator

To seperate liquid, oil, and gas;

B. Based the shapes of Separator can be divided into:1. Horizontal Separator

Used to a flow that have ratio of gas to liquid(Gas-Oil Ratio) is high, for the bubbly flow / for the liquid that comes out from the previous separator;

2. Vertical SeparatorUsed for a fluid flow that have ratio gas-liquid (Gas-Oil Ratio) is low to medium and is expected to occur a liquid that coming shock (slug) in a relatively frequent;

3. Spherical SeparatorSpherical separator is usually only used for small production capacity

THE FACTORS THAT INFLUENCE THE

DESIGN OF SEPARATOR

1.Difference of Density / Mass type; ;

2.Deposition Time A time at which the fluid

stay in the separator;

3.Contact of Surface;

Formula for Design a Separator

21

420

/

m

D

gl

ggeff d

C

ρρ

ρ

P

QZTLd

Keterangan :

d = diameter separator,inLeff = the effective length of the separator where separation

occurs, ftT = operating temperature, oRQg = gas flow rate, (known from experimental data)P = operating pressure, PsiaZ = gas compressibilityρg = density of gas, kg/m3

ρl = density of liquid, kg/m3

CD = coefficient of dragdm = grain size of the liquid to be separated, micron

The capacity of the gas needed to give the combination equations diameter (d) and the effective length of the separator (Leff). The equation used for the separator liquid filled 50% (one-half of the separator) and for the separation of liquid grain diameter of 100 microns is as follows:

persamaan (1)

Calculation procedures of sizing three-phase of horizontal separator are as follows:Preparing Data QL, Qg-, ρg, ρl, m, P, and T;Determining the value of tR;

Calculate d.Leff equation (1) for d <dmax gas that meets the restriction for capacity of gas;

Grain size (dm) that used is 100 microns if the information about it was not available;

Z values obtained by gas compressibility chart;In calculating d.Leff value for gas capacity, the necessary value

coefficient drag (CD) from grain liquid that fall from the gas. CD Rates are determined by the following iteration steps:1. Calculate Vt with this formula : 2/1

0204,0

g

mglt

dV

2. Calculate the value of Re with this formula :

tmg Vd

0049,0Re

34,0Re

3

Re

242/1DC

3. Calculating the value of the CD with the Re value were obtained :

4. Re-count Vt with this formula : 2/1

0119,0

D

m

g

glt C

dV

5. Re-count the Re value (back to the second step) and iterating till the value of CD obtained to constant; Calculate d.Leff equation (1) for d <dmax gas that meets the

restriction of water by equation (1); Determining seam-to-seam length by using one of the following

equations:

Selected combinations of d and LSS that ideal with slenderness ratio (LSS / d) between 3 and 4.

gaskapasitasuntukd

LL effss 12

cairankapasitasuntukLL effss .3

4

Example of Calculating

ProblemSteps of Calculation :1. Determine tR

2. tR = 2 min 2. Counting d.Leff for d <dmax that

meets the capacity restriction of gas. Where dmax = 50

3. We use grain size (dm) 100 micron :

ITEM UNIT VALUE

QgMMSCFD 53,36

QlBLPD 3205,6711

PoperasiPsig 613,8

ToperasioF 42,56

η cp 0,0112

ρgkg/m3 59,8770

ρlkg/m3 529,6824

tRmin 2

Mass flow

gas (m)

ton/day 1216

Mass flow

liquid

ton/day 277,8

Data Calculation of Inlet Separator (Design)

2/1

420

m

D

gl

ggeff d

C

P

QZTLd

Iterating:

*CD = 0,4336Vt = 0,8465

ft/sRe =

2217,5073CD = 0,4145

*CD = 0,4145Vt = 0,8658

ft/sRe =

2268,0659CD = 0,4136

*CD = 0,4136Vt =

0,8667 ft/sRe =

2270,4236CD =

0,4136

Calculate the value of CD Calculate Vt with this formula :

Re-count Vt with this formula :

Calculating the value of the CD with the Re value were obtained :

Calculate the value of Re with this formula :

1495,8023 =0112,0

5710,0.100.8770,590049,00049,0Re

tmg Vd

0,571ft/s

8770,59

100.8770,596824,5290204,00204,0

2/12/1

g

mglt

dV

0,4336 =34,01495,8023

3

1495,8023

2434,0

Re

3

Re

242/12/1DC

2/12/1

0,4336

100

8770,59

8770,596824,5290119,00119,0

D

m

g

glt C

dV

ft/s 0,8465 =

(a.) By using the data comparison of pressure (P) and temperature (T), then the obtained value of Z (compressibility factor). From the graph (Appendix G) obtained Z = 0.84 (Mc Graw-Hill Second Edition).

effss LL .3

4

Counting seam-to-seam length(Lss) with equations for fluid capacity:

(b.) Calculate d.Leff untuk d <dmax that meet the restriction of retention time for oils and water.

7,0.2 lR

eff

QtLd

7,0

)6711,3205(2.2 effLd = 9159,0603

2/1

420

m

D

gl

ggeff d

C

P

QZTLd

2/1

100

4136,0

8770,596824,529

8770,59

8,613

36,53.84,0).56,502(420

effLd = 353,8188 (inch.ft)

Counting seam-to-seam length (LSS) with the equation for Gas capacity:

By Using30<d<5012

dLL effss

Thank You

d Leff LssSlenderness

Ratio Gas

(12Lss/d)

30 11,79396 14,29396 5,717584

32 11,0568375 13,72350417 5,146314063

34 10,40643529 13,23976863 4,672859516

36 9,8283 12,8283 4,2761

38 9,311021053 12,47768772 3,940322438

40 8,84547 12,17880333 3,653641

42 8,424257143 11,92425714 3,406930612

44 8,041336364 11,70800303 3,193091736

46 7,691713043 11,52504638 3,006533837

48 7,371225 11,371225 2,84280625

50 7,076376 11,24304267 2,69833024

The value combination of D and Leff for liquid retention time limits tabulated as

follows:

Cause of Leff in capacity of gas > capacity of liquid. Selected combinations of d and LSS that ideal with slenderness ratio between 3-4. Obtained from the table ,that the ideal size of the separator is :Diameter 38 inch and Lenght 12,4777 ft.

d Leff LssSlenderness

Ratio Gas

(12Lss/d)

30 10,17673365 13,5689782 5,42759128

32 8,94439481 11,92585975 4,472197405

34 7,923062531 10,56408337 3,728500015

36 7,067176146 9,422901529 3,140967176

38 6,342839533 8,457119377 2,670669277

40 5,724412679 7,632550238 2,289765071

42 5,192211046 6,922948062 1,977985161

44 4,730919569 6,307892759 1,720334389

46 4,328478396 5,771304528 1,505557703

48 3,975286582 5,30038211 1,325095527

50 3,663624114 4,884832152 1,172359717

The Value Combination of d, Leff, Lss, & Lss/d for Inlet Separator based Capacity of gas

(Design):