Centrifugal Separators

For Horizontal Piping...

HORIZONTAL T SEPARATOR

Tangential Inlet - angled down to improve separator efficiency. Stainless steel striking plate at inlet impingement significantly reduces sidewall erosion.
Vortex Finder - picks up clean, dry swirling gases from center flow area and directs them to the outlet and back to the flow line.
Penn Cone - PµC™ maximizes separator efficiency. Perforations allow entrainment to harmlessly escape center flow area.
Outer Flow Area - The downward spinning gas flows, in an increasingly smaller concentric pattern, greatly increases the centrifugal force to throw out hard-to-get entrainment.
Drain Baffle - Perforated plate allows for free flow of entrainment to drain area. Re-entrainment is substantially restricted.

The funnel of a cyclone is an example of the shape a swirling gas assumes. This is commonly called a vortex flow. Large "circles" of gas revolve downward into graduated smaller circles, with an ever increasing centrifugal force. Penn's cone-shaped baffle matches the funnel-shaped configuration of the vortex flow and the entire perforated basket helps eliminate moisture from the flow path along its entire length. This cone also has the advantage of providing a dead-airspace outside the centerflow area, where separated water particles drop harmlessly down through the perforated plate to the drain so that moisture cannot be picked up again by the flowing gas. Because the Penn Cyclonic Separator is also designed for natural vortex flow, pressure drop is minimized, while an extremely high separator efficiency is maintained.

FOR VERTICAL PIPING

DOWNFLOW

Entrainment separation is easily accomplished in "down-comers" with the Penn Downflow Separator. Penn's Helical Baffle, PHB™ quietly develops clean, cyclonic spinning permitting reversal of flow to center vortex finder without picking up separated entrainment. Penn's Downflow Separator fits directly into the flow line and requires a minimum of space. Dimensions are available in Spec. sheet No. ID 418- R4

UPFLOW

Penn's Upflow Separator is specifically designed for "pipe-risers". Note that special treatment is given to the insertion of Penn's Helical Baffle, PHB™ so that an area exists outside the main flow area where entrainment can flow to the drain area without being picked up by the main flow steam. The outer wall of the separator forms a boundary on which entrainment droplets continually collect and slip down into the low flow area and from there to the drain.
For dimensions ask for Spec. sheet No. ID 418 - R4

Separator Efficiency

Proper separator sizing is an important factor in solving the entrainment problem. Used of accompanying "Chart S" for steam flow will yield the proper separator selection necessary to insure less than one-half percent entrainment at the exit of the separator, for particles 10 microns and larger. Separator sizes are indicated as functions of operating pressure and mass flow rates. These charts should be used when maximum separation is desired. Determining the final quality (Qf) of the steam flow is simplified by the fact that separator efficiency (Ns) is never less than 98% ON "T" type separators and 90% for straight thru model.

Therefore, knowing the initial quality (Qi), the final quality (Qf) can be solved for from the above equation (solving for Qf). For example, with initial quality of 90%.

Qf = [.98 (1.0- Qi)] + Qi   Qf = 99.8%

If this is a higher exit quality than is necessary for your application, you may be able to optimize separator size, as discussed on page 7.

Separator Pressure Drop

The right side of Chart S gives maximum pressure drop. Simply read horizontally from separator size (at correct PSIA) and read pressure drop on right axis.

Using Chart E

To select the particular separator needed:

1. Know the minimum entrainment acceptable.
2. Using the minimum entrainment acceptable, solve for the minimum acceptable efficiency by using equation Ns= QF-QI / 1.O-QI as discussed on page 5. Where QF=Final Quality and QI=lnlet Quality

3. From Chart E find the corresponding inlet velocity. (For example, if a 95.4% separator efficiency is required, an inlet velocity of 130 f.p.s. can be used.)

4. Inlet diameter, d in inches, may be determined from the following equations. For steam,

where m is the #/Hr. flow, v is the steam's specific volume (see Fig. 8), V is the inlet velocity from Chart E in F.P.S. For gases;

where SCFM is the standard volume flow (@60°F, 14.7 psia), P is the PSIA operating pressure, Ft and Fg are Figure 5 and 6 correction factors (Fg=1 when gas is Air), V is the inlet velocity from Chart E in F.P.S.

If the diameter is calculated to be an intermediate value between nominal diameters, the next largest nominal diameter should be chosen to assure the required efficiency.

TEMPERATURE CORRECTION FACTOR CHART Fig. 5-FT

Since the selector chart for gases (Chart A) is based on the air flow at 60°F, a correction factor is necessary when using other gases and temperatures. Figures 5 and 6 determine these factors, corresponding to gas operating temperature and molecular weight. A table of molecular weights for common gases is found in Figure 7. When the known gas flow rate is multiplied by these correction factors, Ft and Fg, the equivalent air flow rate (EAFR=SCFM x Ft x Fg) is determined and the selector Chart A is ready for use.

(Note that when the gas is air at 60°F, the correction factors are one so that the known flow rate is the equivalent flow rate, at standard temperature and pressure (STP) conditions.)

Table of Specific Volumes - Fig. 8 Operating psig Pressure psia S.P. Vol. ft3/lbm 0 14.7 28.83 5 20 20.09 10 25 16.30 20 35 11.90 30 45 9.40 40 55 7.79 50 65 6.65 60 75 5.81 80 95 4.65 100 115 3.88 125 140 3.22 150 165 2.75 175 190 2.40 200 215 2.14 250 265 1.74 300 315 1.47 400 415 1.12 500 515 0.90 (Note: interpolate for intermediate pressure) Table of Molecular Weights - Fig. 7 Substance Formula MW Acetylene C2H2 26.00 Ammonia NH3 17.03 Argon Ar 39.94 Carbon Dioxide CO2 44.01 Carbon Monoxide CO 28.01 Chlorine CL2 70.91 Ethane C2H6 30.07 Helium He 4.00 Hydrogen H2 2.02 Methane CH4 16.04 Natural Gas 75% CH4; 25% N2 19.00 Nitrogen N2 28.02 Nitrous Oxide N2O 44.02 Oxygen O2 32.00 Propane C3H8 44.10 Sulfur Dioxide SO2 64.06

To provide clean dry steam from a low or high pressure boiler a Penn Centrifugal Steam Separator is installed on the steam header from the boiler. This Separator can provide steam of 99.8% quality. The drain of the separator can be piped back to the system or drain. (See Fig. 2)

Other uses include cleaning steam prior to turbines, Autoclaves, and other steam powered equipment.

A Penn Inline Separator is often used between the compressor and the Air Dryer. The separator can clean moisture from the air before the air enters the dryer. The separator does not lower the dew point of the air, but can increase the efficiency or down time of the dryer. (See Fig. 3)

Separators are also used prior to air operated equipment, on natural gas lines, or on other air or gas process.