154- Design of multi-factor swirl parent-separator and vane separator for the inlet separator of C4 cycle gas compressors

In petrochemical plants, in units such as atmospheric and vacuum distillation as well as fractionation units, C4 fractions are pumped to higher pressures using compressors for transportation. In the butadiene stripping unit, C4 gases are also transported under pressure through a compressor process. As for the process of pressurizing and transporting the C4 cycle gas via a compressor, this is commonly seen in facilities for the further processing of C4 fractions.

For C4 gases, their properties make it easy to liquefy them under pressure; moreover, C4 gases often contain olefins, and the oligomers of these compounds are viscous. For carbon tetrafluoride gas compression equipment, when selecting the technical design for the inlet separator, it is not advisable to use screen or filter element types of components for separation; this is to avoid frequent clogging of such components as well as the need for regular replacement and maintenance, which would result in high operational and maintenance costs.

Here, the inlet separator of the butylene recycle gas compressor in the design of a C4 deep processing project is taken as an example for analysis and discussion.

The basic operating condition data for the inlet separator of this butane cycle gas compressor was finally edited and organized by luoli519 on 2020-5-28 at 10:47. 1. Operating temperature: 125℃； 2. Operating pressure: 2.0 MPaG ； 3. Gas flow rate: 1008 Kg/h ； 4. Air flow viscosity: 0.013cp ； 5. Composition of the circulating gas: Isobutane, n-Butane, TBA, Propane, Ethane, Methanol, TBHP, Water – 85.7%, 1.6%, 8.5%, 1.3%, 0.2%, 1.0%, 0.3%, 1.2%

The customer requires the design of two inlet separators for their butene recycle gas compressors, using a multi-factor cyclone mother-son separation technology. It is presumed that there are two production lines, each equipped with 2 sets of compressors along with corresponding separators. The multi-factor swirl parent-child separator belongs to the anti-clogging dynamic separation type; unlike screen and filter element-based separators which tend to clog and thus require alternating use of one unit while another is on standby, this separator does not have such a problem. The multi-factor swirl parent-child separator does not require a backup unit.

Based on the basic operating parameters provided by the client, and utilizing our advanced dynamic separation technology design platform, the technical specifications for the multi-factor swirl separator used at the inlet of the butane cycle gas compressor are as follows: I) Design Platform: Novel Proprietary; II) Vessel ID x TL/TL: Inner diameter of the vessel x length of the straight sides: ID 8” x TL/TL 50”; III) C.A. Corrosion allowance: 0.118” (3 mm); IV) Total Pressure Loss (Inlet/Outlet): 1.3 psi (~0.009 MPa); V) Separation efficiency: 100% removal of droplets with a size of 8.75 μm or larger from the gas phase. The outlet gas will contain no more than 0.1 gallon of entrained droplets per MMSCF of gas that passes through the separator. 100% of liquid droplets with a size of 8.75 microns or greater are removed from the gas stream, with the droplet content in the outlet gas being less than 0.1 gallons per million cubic feet.

After reviewing our technical documentation regarding the multi-factor swirl separator for the inlet of this butane cycle gas compressor, we provide the following additional information: Key components: 1) The shell of the G54 high-pressure CNG compressor suction separator, which includes the cylinder, heads, nozzles, flanges, gaskets, bolts, and nuts. Model G54-8-1740.4. It was manufactured by the buyer according to Novel’s designs. The shell of the high-pressure natural gas compressor inlet separator comprises the cylinder body, end caps, connections, flanges, gaskets, as well as bolts and nuts. Model G54-8-1740.4. To be manufactured by the buyer according to the Novel dimension drawings. 2). G54 Cyclone Internals, which include the cyclone element, spiral tubes, equilibrium tubes, top support plate, and bottom support plate. NOVEL G54-12. Supplied by Novel. The G54 multi-factor cyclone internals consist of a cyclone element, spiral conduits, equilibrium tubes, as well as upper and lower tube plates. NEW G54-12. Supplied by Novel. Separator materials: 1) Shell of the G54 High Pressure CNG Compressor Suction Separator. Equivalent to Q345R. Shell of the inlet separator for the G54 high-pressure natural gas compressor. Materials equivalent to Q345R. 2). G54 Cyclone Internals. 16Mn Equivalent. G54 multi-factor cyclone internals. Materials equivalent to 16Mn. Nozzles and Openings of Separator: Configuration of the separator’s outlets: As per the attached drawings from Novel. Refer to the drawings provided by Novel.

This post was last edited by luoli519 on 2020-5-30 at 17:07. The figure below shows the multi-factor swirl separator for the inlet of the butane cycle gas compressor, which was developed by Nuowei Energy Technology Company using its NOVEL precise dynamics separation technology design platform, based on the operating condition data provided by the customer – “Table of Figures and Data”

The customer specified the use of a multi-factor swirl separator for mother-son separation in the technical requirements. In fact, the actual operating pressure of 2.0 MPaG at the inlet separator of the aforementioned butane cycle gas compressor is by no means considered to be below high-pressure or ultra-high-pressure conditions. Therefore, the vane separator was chosen; under these operating conditions, it has advantages over the swirl separator in terms of operational flexibility, pressure drop during operation, and manufacturing cost, among other factors.

For the specific technical performance parameters of dynamic separators such as feather leaf separators and multi-factor swirl parent-child separators, please visit the website of Novae Energy Technology Company or contact them directly to inquire about cooperation.