Knockout drum design pdf

Knockout drum level water seal level, pressure, and temperature steam flow to flare collection header purge gas flow flare gas recovery control and monitoring equipment may not be available for maintenance with flare system in service each flare system. Design a vertical gasliquid separator or a knock out drum for separation of liquid droplets entrained in fuel gas flow. Gasliquid separation technology sulzer is a major player in the field of gasliquid and liquidliquid separation technology, offering a full range of innovative products and related services. Ergil has collaborated with gazprom neft middle east b. The liquid in this case is water and the fuel gas phase can be considered to be mostly ethane. Flare knock out drum selection, sizing and troubleshooting kolmetz handbook of process equipment design. Klm technology group practical engineering guidelines for processing plant solutions olefin compressor engineering design guidelines page 5 of 63 rev. The vapor travels upward at a design velocity which minimizes the entrainment of any liquid droplets in the vapor as it exits the top of the vessel.

In the case of low pressure oil wells, the liquid phase will be large in volume as compared to the gas phase. There are a number of reasons why such devices may be needed. Technology new program sizes pressurerelief drums oil. Therefore i thus is a function of the particle reynolds number. In many such vessels, a mist eliminator is provided to r emove. Flaring is defined as a process of controlled burning of exhaust gases which generates heat and noise. Amine flash drum 5 10 minutes glycol flash drum 10 20 minutes cold separator gasngleg 15 30 minutes refrigeration accumulator 5 minutes or based on system requirements refrigeration economizer 3 minutes heat medium surge drum max liquid expansion based on 25% 75% full 28 ref. Condensation can occur when hot process gases cool considerably in the flare gas header and. Flare, knockout drum and flare gas recovery systems registration closing date. A vaporliquid separator drum is a vertical vessel into which a liquid and vapor mixture or a flashing liquid is fed and wherein the liquid is separated by gravity, falls to the bottom of the vessel, and is withdrawn. Flash distillation martin iggland, marco mazzotti eth zurich, institute of process engineering, sonneggstrasse 3, ch8092 zurich, switzerland 1. The flare can handle small sized liquid droplets, making it only necessary for the drum to separate droplets above the 300 to 600 microns range typically above 400 microns. The hydraulic design is a line sizing rating problem design minimizes the differential pressure to ensure each pressure relief device functions properly design is based on specific line size, line length and. These two types of process vessels are utilized throughout the chemical process.

I have a spreadsheet for sizing the knockout drum based on the souderbrown equation, so i will be using the same. The selection and design of knockout drums and catchtanks has been described by grossel 1986. Generally, the drums are designed and built with the same design pressure as the flare header or with 50 psi to resist explosions, see eq. In general, vapor velocity is the dominating factor in determination of the vessel diameter. The condensed hydrocarbon components and water are then recycled and flashed from high pressure suction or knockout drums to the ones at lower pressure to recover the lighter hydrocarbon. The flare line from the units should slope down to drain to the flare knock out drum and the line from the flare knock out drum to the flare stack needs to slope up to drain back to the ko drum. The knockout drum is a powerful tool to remove the combined liquids from a gas stream. Most compressor suction knockout drums are arranged vertically. A flare knockout drum is a vessel in the flare header, designed to remove and accumulate the liquids that are condensed from the relief gases.

The structure of ko drums generally depends on the operating parameters and other plant conditions. Force is dependent on velocity, cross sectional area, density and. Indeed such a knock out drum figure1 is still in use today and it is still being built for new geothermal projects. However, because of the need for a mist eliminator support ring, and because of roundup to the next standard vessel diameter, vertical knockout drums typically have a design. Flaring is a common practice in oilgas exploration, production and processing operations.

The liquids that are discharged from the freewater knockout are further treated in vessels. For optimum separation performance, compressor knockout drums must be properly designed and sized with appropriate mist eliminator elements in correct con. Industries includes a knockout drum in the system design. Further information on typical flare system design can be found in iso 23251 2006. These design guideline are believed to be as accurate as possible, but are very general and not for specific design cases. Pdf parametric approach for the optimal design of knockout. Executive summary an ethylene production plant was designed to meet a product speci cation of 700 metric tons per day. Design of a vaporliquid separator drum or knockout pot, or. Sample problem vertical knock out drum sizing calculations. The knockout drum is designed to completely retain the liquid fraction. To access the working calculator, please sign up for free membership trial this calculator can be used to size a horizontal two phase separator for removal of liquid droplets, such as a knock out drum.

It is achieved by applying good design principles, engineering, and operating and maintenance practices. Design the size of a vaporliquid separator drum or knockout pot, or flash drum, or compressor suction drum is dictated by the anticipated flow rate of vapor and liquid from the drum. Knockout drum description top of whenever a process requires that entrained droplets be removed from a vapor stream, aereons flare industries includes a knockout drum in the system design. The knockout drums are generally set with high efficiency mist eliminators to minimize the carryover of liquid to the following compressor stage. It is important for all parties involved in the design and use of a flare system to have an effective means of communicating and preserving design information about the flare system. Total flare system design and analysis a simple knockout drum no mist eliminator will remove droplets larger than about 380 microns by. Tipe vertikaltipe vertikal keuntungan tipe vertikalkeuntungan tipe vertikalplot area yang diperlukan lebih kecil ppg g penghilangan padatan lebih mudah efisiensi penghilangan cairan tidak dipengaruhi oleh ketinggian. Abstract sizing criteria and design procedures for knock. Figure 1 shows an image of an onshore elevated flare stack where the knockout drum, seal drum, flare stack, molecular seal and flare tip are all visible. This is a sample of the 2 phase separator design calculator. Flash distillation flash evaporation is one of the simplest separation processes. Detailed explanation of high performance vaporliquid separators scrubbers vapor liquid separator designs and manufacturing process. These can be made available in both vertical as well as horizontal configurations.

Operating pressure the operating pressure is the pressure in the vessel during normal operation. Using an efficient mist eliminator will prevent entrainment of all drops larger than 5 to 10 microns. Determine mechanical design of drum that best fits process use safety environment cost effectiveness determine key elements of drum design volume dimensions. A flare system consists of a flare stack and pipes that feed gas to the stack. High back pressure on pressure safety valves psvs in a flare system developing the simulation model, identifying and. A freewater knockout is commonly called a threephase separator because it can separate gas, oil and free water. In the case of a knockout drum suction of a compressor must be designed for the worst case of liquid entrainment that may arise under operating conditions apply a safety factor. Separator design for liquid removal from gas streams john pietranski p. In multistage compressor installas, the proper knockout drum design is seldom the same for all stages. During the design phase there is flexibility between the number of stages, the.

Vessel sizing, internals, safety systems, measurement devices, pipecomponent sizing, etc. In this paper, the optimal design of twophase horizontal knockout drums is addressed. Knockout drums designing knockout drums to include mist eliminators will reduce capital equipment costs and improve efficiency. To obtain the basic relief drum program, journal subscribers can. Pdf in this paper, the optimal design of twophase horizontal knockout drums is addressed. It needs to be precisely designed because the failure of the equipment may lead to economic loss, as well as safety and health risks. Potential auxiliary equipment includes smokesuppression control, blowers, staging equipment, monitors e. So, from my side my groundwork is almost done and seems to be sufficient. Parametric approach for the optimal design of knockout drums. Flare knockout drums working animation instrumentation tools. Olavo cunha leite, olavo cunha leite, in underbalanced drilling.

Separator development water and steam can be separated by flowing the mixture into a large drum. Different design criteria must be used in sizing and selecting a separator for a hydrocarbon stream based on the composition of the fluid mixture. Flash drum design che 4253 design i dimensional analysis for drag. Design of vaporliquid separator knockout drum, flash drum. Difference between knock out drum and flash drum youtube. Design of gasliquid separator for complete degasing. Difference between knock out drum and flash drum alchemy academy. The vessels are design tangential inlet which allows to scrub out the vapoursliquid in gas application. The vapor travels through the gas outlet at a design velocity which minimises the entrainment of any liquid droplets in the vapor as it exits the vessel. Drum, knockout pp, pot, compressor suction drum or compressor inlet drum 2. To this end, api has developed a set of flare datasheets. Knock out pot flow rates are to be calculated via the design of service software package taking into consideration all variables i.

Pdf parametric approach for the optimal design of knockout drums. Hydraulic design flare header is sized to limit the back pressure of each pressure relief device during various emergency events. T back end c2 hydrogenation for ethylene production. Depending on the flow rates and the required separation efficiencies we design and fabricate knockout drums to suit your operational requirements. A knockout drum vertical or horizontal is typically sized for a system load factor of 0. Green oil in ethylene production 48 hydrocarbon asia, janfeb 2007 with permission from publisher of hydrocarbon asia website.

Gravity causes the liquid to settle to the bottom of the vessel, where it is. Knock out vessels are used to slow down gasses and allow liquids to fall out of the gas stream. Contact your local halliburton swt representative for more information. It is assumed that the compression ratio is constant, and that there is a 6 psi pressure drop across each knockout drum. He is also a member of the american chemical society, fine particle society and the combustion institute. Flare design also depends on the sources of the gas being. An optimization model is developed that predicts separator performance subject to nonlinear design constraints. Introduction to chemical engineering for lecture 7. If installed on a personal computer, the program can be used to design a knockout drum or evaluate one in service. Knockout drums relying solely on gravity settling remove only drops larger than 100 microns. Here, the liquid collects at the bottom of the vessel while the gas flows at the upstream.

Sizing criteria and design procedures for knockout drums and catch tanks used in reactor emergency relief systems. Results of indepth analysis aimed to characterize liquid gas separation in horizontal. A liquid stream containing several components is partially. However, because of the need for a mist eliminator support ring, and because of roundup to the next standard vessel diameter, vertical knockout drums typically have a design system load of 0. Additionally i also referred to the gpsa guidelines for the knockout drum design.

Compressor suction drums amacs process tower internals. Excel how to design entrainment separation vessels. Background this course provides a stepbystep development for the design of two types of liquidingas separation devices. Equipment design specification project standards and specifications page 3 of 22 rev.

To do so, 140,010 lbhr of 100% butane is fed to the plant, and 100% of ethane is recycled. The conventional ar rangement is a mesh pad located immediately bel ow the gas exit as in figure 2. Process design of gas vapor liquid separators project standards and specifications page 4 of 45 rev. Condensation can occur when hot process gases cool considerably in the flare gas header and riser, and some gases also go to dew point at ambient. Gbp 3,200 get 10% discount for second and subsequent attendees from same company paid on registration register now limited number of seats available dedicated registration fax. The size a vaporliquid separator drum or knockout pot, or flash drum, or compressor suction drum should be dictated by the anticipated flow rate of vapor and liquid from the drum.

Sarda, and thomas mathew international journal of chemical engineering and applications, vol. Force is dependent on velocity, cross sectional area, density and viscosity. Our commitment to development of technology, combined with application skills and consistent fabrication standards. They were designed for engineers to do preliminary designs and process specification sheets. Design of vaporliquid separator knockout drum, flash drum in metric units. Where there may be solids in the drum, which are not to be drawn off, the liquid outlet may be raised and the low liquid level shall be increased accordingly. A vertical or horizontal separator used mainly to remove any free water that can cause problems such as corrosion and formation of hydrates or tight emulsions, which are difficult to break. High back pressure on pressure safety valves psvs in a. Flash vaporization design of knockout drum brainmass. The liquids that are discharged from the freewater knockout are further treated in vessels called treaters. Compressor suction knockout drum refining, hydrocarbons. He is head of process technology and design methods section, corporate engineering department at hoffman. Quick calculator for horizontal knock out drum sizing based on minimum time required for liquid droplets of a given minimum size to be separated. Design of a vaporliquid separator drum or knockout pot.

So i can place the stack basically anywhere, but i guess another question is are there benefits to placing the knockout drum closer to the rest of the equipment or closer to the flare. In the case of high pressure gas distillate wells the gas volume will. The lighter steam will rise up while the heavier water will fall to the bottom of the drum. The feed to a vaporliquid separator may also be a liquid that is being partially or totally flashed into a vapor and liquid as it enters the separator. A knockout drum and a heat exchanger follow the first three compressor stages, where water and hydrocarbons are removed. The final design must always be guaranteed for the service selected by the manufacturing vendor, but these guidelines will. Separator design for liquid removal from gas streams.