Ammonia desuperheater used in refrigeration

Rajesh (Senior Engineer) (30 Points)

12 January 2018

Desuperheater is a device used to save the energy by cooling a superheated steam in a power generation plant. Superheated steam has important advantages on certain applications, for example, when used in power stations to drive turbines. For efficient use on heating applications however, the steam must be desuperheated.

Desuperheating is the process by which superheated steam is restored to its saturated state, or the superheat temperature is reduced. Basically there are two types of superheaters.

• Indirect contact type - The medium used to cool the superheated steam does not come into direct contact with it. A cooler liquid or gas may be employed as the cooling medium, for example, the surrounding air. Examples of this type of desuperheater are shell and tube heat exchangers.

• Direct contact type - The medium used to cool the superheated steam comes into direct contact with it. In most cases, the cooling medium is the same fluid as the vapour to be desuperheated, but in the liquid state. For example, in the case of steam desuperheaters, water is used.

Design Features of a Desuperheater

High efficient atomization.
Accurate and repeatable control fluid temperature.
Tight shut off variable spray unit.
High range ability variable area spray unit.
Erosion resistance materials of selection.
Ease of installation.
Low maintenance features.
High integrity sealing arrangement.
Thoroughly checked at factory to ensure that it meets the specified performance on site with high integrity.
Quality assurance at every stage of manufacturing.
Comprehensively designed and tested to ensure its optimum performance for the tough process Parameters specified.