The history of the Institute of Process Engineering of the Brno University of Technology (BUT), Czech Republic, dates right back to 1960, when the core centre was established. Since that time the centre has gone through several changes before eventually taking its present form as an independent institute that is one of the world’s leading centres in its field. The Institute has several departments, including the Department of Thermal Processes and Gas Purification, which is engaged in the development of burners. In recent years, the main experts at the department Ing. Pavel Skryja and Ing. Petr Bělohradský, Ph.D. have been participating in the development of all below-mentioned burners.
When developing new types of burner, it is important to make maximum use of both gaseous and liquid waste. A combined oil-and-gas fired burner, ensuring a high stability of burning is one of the proposed burners. The burner is able to fire e.g. gaseous fuels with a low heating value and liquid biofuels or liquid wastes that are by-products resulting from the production of biofuels. The burner is suitable for process furnaces and afterburning chambers. The gas burner is a ‘Low NOx’ type (i.e. production of oxides of nitrogen is suppressed) and equipped with a stepped fuel supply. Liquid fuel is dispersed under pressure. This burner is protected as a utility model.
Even when greater amounts of excessive combustion air are present, e.g. when lean fuels are being burnt, burning stability is ensured by means of a special burner head. The principle of this technical solution lies in a burner head designed as a toroid and equipped with high-performance nozzles in the front chamfering area. Underneath there are stabilization nozzles and a flame holder. This burner head is protected as a utility model and is patented. In addition, a European Patent Application has been filed. Liquid fuel is dispersed using three special pressure nozzles. The unique solution of such arrangement allows for the thorough mixing of liquid fuel and combustion air.
An injection-type stabilization burner intended for industrial boilers and furnaces with an output of 10 to 30 kW has also been innovated. In this case scientists concentrated their efforts on the burner head and made it removable. An ignition and flame-sensing electrode runs through it and the combustion of the gas-and-air mixture takes place inside. Its major advantage lies in its design, which ensures that burning is highly stable. The head also has a high resistance to ‘flashback’ (especially in the case of hydrogenous gases). The innovated burner head can be used for multiple burner types, i.e. for both stabilization and injection-type ignition burners. All they need is a suitable end piece to be connected. The solution described here is protected with a patent.
The other two burners are intended for burning gaseous fuel, especially to generate heat in overpressure or vacuum boilers, i.e. for power generation plants. They are monoblock types and feature two-stage burning. Burning stage I occurs in the combustion channel and is characterized by a swirling flame, whilst burning stage II occurs upstream of the burner and is characterized by a free flame.The former is protected as a utility model and a patent application has been filed. With respect to its combustion channel – characterized by burning fuel with a high amount of excess oxygen – the burner is quite unique. For firing stage II, four secondary nozzles are used. The latter design is also protected as a utility model and a CZ and European patent application have been filed. Both burner types are characterized by burning 20% fuel in the stage I combustion channel using a specially developed burner head and a swirler. For firing stage II, six secondary nozzles are used. Both burners are ‘Low NOx’ types, so they offer considerably improved burning, including reduced concentrations of harmful emissions. They were developed in cooperation with PBS Power Equipment, s. r. o. as part of the ALFA Programme project run by the Technology Agency of the Czech Republic (TAČR ALFA).
The latest invention solves the issue of how to dispose of oils containing various impurities. These impurities in general prevent the burning of oils, because they cause the clogging of nozzles. The proposed YE – atomization nozzle allows the burning of oils with particular substances up to a size of 2 mm. Such oils occur when materials are processed by pyrolysis, or they can be trapped in the waste water treatment facilities of chemical plants or refineries. The nozzle can be installed in common steam and hot water boilers or process furnaces without significant difficulty or excessive investment costs. The new technology will enable waste oil to be used as fuel, while at the same time complying with the statutory regulations. Hence operators will not only save costs otherwise spent on waste oil disposal, but also will not need to purchase conventional fuel. A Czech and European patent applications have been filed and utility model have been gained for the YE - atomization nozzle design.
Source of illustrations: Flame – Ludmila Navrátilová, CTT
Burner – authors’ archive, ÚPI
Refinery - https://commons.wikimedia.org/wiki/File:Vohburg_BayOil1.jpg
