Descripción: TWO PHASE FLOW, SLUG FLOW, HEAT TRANSFER
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Catchers of Heaven OverviewFull description
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Slug Catcher Sizing SpreadsheetFull description
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Design Guide and Reporting Template
Descripción: Slug Catcher Sizing Spreadsheet
Descripción: Consulta SLUG
Two options are available for separating the gas liquid mixture at the exit of a two phase flow pipeline operating under slug flow conditions. These are a traditional vessel type separator and a...
Descripción: Two options are available for separating the gas liquid mixture at the exit of a two phase flow pipeline operating under slug flow conditions. These are a traditional vessel type separator and a...
Descripción: slug catcher equipos flujos
Descripción: Design Guide and Reporting Template
Design Guide and Reporting TemplateFull description
Slugcatcher is the name of a unit in the gas refinery or petroleum industry in which slugs at the outlet of pipelines are collected or caught. A slug is a large quantity of gas or liquid that exists in the pipeline.
Slugs existing in the pipeline can overload the gas/liquid handling capacity of the plant at the pipeline outlet, as they are often produced at a much larger rate than the equipment is designed for. Slugs can be generated by different mechanisms in a pipeline:
• Terrain Slugging is caused by the elevations in the pipeline, which follows the ground elevation or sea bed. Liquid can accumulate at a low point of the pipeline until sufficient pressure builds up behind it. Once the liquid is pushed out of the low point, it can form a plug.
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•Hydrodynamic slugging is caused by gas flowing at a fast rate over a slower flowing liquid phase. The gas will form waves on the liquid surface, which may grow to bridge the whole cross section of the line. This creates a blockage on the gas flow, which travels as a slug through the line.
• Riser Based Slugging also known as severe slugging is associated with the pipeline risers often found in offshore oil production facilities. Liquids accumulate at the bottom of the riser until sufficient pressure is generated behind it to push the liquids over the top of the riser, overcoming the static head. Behind this slug of liquid follows a slug of gas, until sufficient liquids have accumulated at the bottom to form a new liquid plug.
Slugs formed by terrain slugging, hydrodynamic slugging or riser based slugging are periodical in nature. Whether a slug is able to reach the outlet of the pipeline depends on the rate at which liquids are added to the slug at the front (ie. in the direction of the flow) and the rate at which liquids leave the slug at the back. Some slugs will grow as they travel the pipeline, while others are dampened and disappear before reaching the outlet of the pipeline.
• A slug catcher is a vessel with a significant buffer volume to store the largest slugs expected from the upstream system. • The slug catcher is located between the outlet of the pipeline and the processing equipment. • The buffered liquids can be drained to the processing equipment at a much slower rate to prevent overloading the system. As slugs are a periodical phenomenon, the slug catcher should be emptied before the next slug arrives. • Slug catchers can be used continuously or on demand. • A slug catcher permanently connected to the pipeline will buffer all production, including the slugs, before it is sent to the gas and liquid handling facilities
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• This is used for difficult to predict slugging behaviour found in terrain slugging, hydrodynamic slugging or riser based slugging. • The slug catcher can be by-passed in normal operation and be brought online when a slug is expected, usually during pigging operations.
Slug catchers are used at the terminus of offshore pipelines: to catch large slugs of liquid in pipelines, to hold these slugs temporarily, and then to allow them to follow into downstream equipment and facilities at a rate at which the liquid can be handled properly.
Slug catchers may be either a vessel or constructed of
vessel-type slug catcher could range from a simple knock-out vessel to a more sophisticated lay-out. This type is preferred in the case of limited plot sizes (e.g. offshore platforms).
made of pipeline materials. This type allows for wide ranges of flow situations and configurations with different shapes of the available ground area. The advantage of a multiplepipe slug catcher is that it is easy to operate since no flow controls are required.
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Types of Slug catcher
Multiple-pipe slug catcher (continue1) The configuration of a pipe-type slug catcher consists of the following parts: Fingers for gas/liquid separation and liquid storage capacity
parts are virtually disconnected. It consists basically of a large separator with the liquid outlet connected to a long single pipe-loop. The incoming gas/liquid stream is separated in the vessel.
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This type of slug catcher is particularly suited to offshore applications where the separator can be placed on the platform and the parking loop on the sea-bed.
Slug catcher volume (VSC) must be able to: 1. intercept the maximum possible slug size emerging from the two-phase pipeline at any moment (VINT). 2. It should also contain a buffer volume of condensate (VBUFFER) in order to guarantee liquid supply to treating facilities downstream of the slug catcher.
The intercepting capacity of the slug catcher is determined by the nature and operating philosophy of the system. If the pipeline is to be pigged regularly, it can be sized according to the amount of liquid expected to accumulate between pigging intervals.
(SGV) based on equilibrium hold-up conditions can be very large and a special operating and pigging philosophy may have to be devised to limit the size of a slug catcher. The size of (VBUFFER) is largely determined by the characteristics of the liquid-treatment facilities and required plant flexibility.
