{"id":14649,"date":"2021-08-17T15:45:00","date_gmt":"2021-08-17T20:45:00","guid":{"rendered":"https:\/\/blog.wika.com\/us\/\/?p=14649"},"modified":"2025-11-07T14:05:52","modified_gmt":"2025-11-07T19:05:52","slug":"venturi-nozzles-reduce-uneven-coking-ethylene-production","status":"publish","type":"post","link":"https:\/\/blog.wika.com\/us\/applications\/venturi-nozzles-reduce-uneven-coking-ethylene-production\/","title":{"rendered":"Venturi Nozzles Improve Flow Distribution, Reduce Uneven Coking During Ethylene Production"},"content":{"rendered":"

Venturi nozzles help regulate feedstock flow rates in order to minimize uneven coking inside the radiant tube walls of furnaces. Along with tubeskin thermocouple assemblies, Venturi nozzles enable ethylene crackers to operate more efficiently.<\/strong><\/p>\n

Refineries<\/a> and petrochemical<\/a> plants are familiar with WIKA\u2019s many temperature measurement solutions \u2013<\/a>\u00a0our multipoint thermocouple assemblies<\/a> and other electronic temperature sensors are the go-to options for hydrocrackers<\/a>, hydrotreaters<\/a>, steam methane reformers<\/a>, and distillation units. But our instruments for process industries do not stop there. WIKA also manufactures critical Venturi nozzles and other primary flow elements for ethylene crackers.<\/p>\n

Steam cracking process in ethylene production<\/h2>\n

The most common way to obtain ethylene (C2<\/sub>H4<\/sub>) is to use steam to break the long carbon chains of ethane (C2<\/sub>H6<\/sub>) and other hydrocarbons. This is pyrolysis, or steam cracking \u2013 a very demanding process with some of the harshest working conditions in the industry.<\/p>\n

A typical cracking furnace has one or two rectangular fireboxes with vertical radiant coils in the center between two radiant refractory walls. These radiant coils superheat the hydrocarbon feedstock and the steam stream, with the reaction products in the tubes reaching temperatures of up to 1,560\u00b0F (850\u00b0C). In addition to extremely high temperatures, steam crackers must also deal with high pressures and corrosive media.<\/p>\n

What is coke formation in thermal cracking?<\/h2>\n

A major challenge of ethylene production is coke formation during steam cracking. Coking and fouling occur when the high-boiling-point molecules formed during cracking collect inside radiant furnace tubes<\/a> and then polymerize.\u00a0This coke layer increases the temperature of furnace tubes, and the results are additional pressure drops, reduced yield, increased energy consumption, and shortened tube life.<\/p>\n

What determines how much coke is formed on tube walls?<\/h2>\n

The amount of coke formed on a furnace\u2019s tube walls is a function of several factors:<\/p>\n