How does a flash drum work?

How does a flash drum work?

A liquid stream containing several components is partially vaporised in a ”flash drum” at a certain pressure and temperature. Because of the large drop in pressure, part of the fluid vaporizes. The vapor is taken off overhead, while the liquid drains to the bottom of the drum, where it is withdrawn.

What does flash drum mean?

[′flash ‚drəm] (chemical engineering) A facility, such as a tower, which receives the products of a preheater or heat exchanger to release pressure; volatile components are vaporized and separated for further fractionation.

What is a flash evaporator used for?

Flash evaporator and liquid-vapor separator are the simplest separation equipment used in chemical industry. Liquid-vapor separators are only used for phase separation, whereas flash evaporators allow for a partial or total component separation.

Why is flash distillation used?

Flash distillation is used in practice for components with large relative volatility, or if the separation based on the vapor–liquid equilibrium (distillation) can be combined with a physical separation based on a liquid–liquid equilibrium.

What does flash separator do?

The purpose of the flash separator is to remove any gas and condensate hydrocarbons from the glycol that was absorbed in the contact tower from the gas stream. “Flashing” refers to the process of liquid hydrocarbons immediately transitioning into vapor when moving from high to low pressure.

What does a flash separator do?

What is a flash type evaporator?

In a flash type evaporator, heated salt water passes through an orifice into an area of lower pressure which is created by an air ejector or vacuum pump. In a two-stage evaporator, water is drawn into the second stage by a lower pressure and the flashing/condensing procedure is repeated.

How do you size a flash drum?

Use a vertical pressure vessel with a length-to-diameter ratio of about 3 to 4, and size the vessel to provide about 5 minutes of liquid inventory between the normal liquid level and the bottom of the vessel (with the normal liquid level being at about the vessel’s half-full level).

What is flash drum used for?

A vapor–liquid separator may also be referred to as a flash drum, breakpot, knock-out drum or knock-out pot, compressor suction drum, suction scrubber or compressor inlet drum, or vent scrubber. When used to remove suspended water droplets from streams of air, it is often called a demister.

Why do flash drums have a mesh pad?

A mesh pad in the upper part of the vessel aids separation and prevents liquid from being carried over with the vapor. 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.

What is a knockout drum?

A Knock-out (KO) drum consists of a vertical vessel specially designed to separate vapor and liquid from a two-phase process flow. Inside you’ll find an inlet diffuser and de-entrainment mesh pad designed to maximize the collection of liquid contained in the vapor as it travels to the top of the vessel.