WO2002066896A1

WO2002066896A1 - Method for the use of exhausted water steam during the combustion of solid fuels, liquid fuels and gaseous fuels

Info

Publication number: WO2002066896A1
Application number: PCT/BG2002/000003
Authority: WO
Inventors: Boiko Raichev Bojilov; Raicho Boikov Bojilov
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-02-16
Filing date: 2002-02-11
Publication date: 2002-08-29
Anticipated expiration: 2003-08-16
Also published as: BG105259A

Abstract

During the combustion of Industrial Fuels, part of the flame is characterized as a zone of incomplete combustion. Its chemical composition and its temperature create favorable conditions for the reactions typical for the gasification of fuels and for the conversion of generator gases. The exhausted water steam is insufflated into the zone of incomplete combustion by a porous catalyzing nozzle situated in the zone of incomplete combustion and made of a material catalyzing the reactions. The light radiation facilitates these chemical reactions, and it focuses on the porous catalyzing nozzle. The energy of the light radiation depends on the wavelength in the visible and invisible part of the spectrum. A change in the wavelength influences the reactions taking place on the surface of the porous catalyzing nozzle and its proximity.

Description

Method for the Use of Exhausted Water Steam during the Combustion of Solid Fuels, Liquid Fuels, and Gaseous Fuels

Many industrial technologies have certain temperature and thermal requirements. For certain technologies, these requirements are achieved through the combustion of solid fuels, liquid fuels, and gaseous fuels.

The fuels for industrial use differ not only in their physical condition but also in their composition The content of useful (combustible) components, the content of mineral additives and ballast, and the content of deleterious additives determine the worth of a certain fuel. Hydrogen and Carbon are the most important elements of fuels. In solid and liquid fuels, carbon constitutes the major element in the combustible mass and the quantity of hydrogen is considerably smaller than the quantity of carbon At the same time, hydrogen's heat of combustion is roughly three times carbon's heat of combustion. Therefore, an increase in the content of hydrogen in fuels increases their value.

The combustion of fuels is a complex and dynamic process. During combustion, the generated flame is not homogeneous in both composition and temperature. The central part of the flame is deoxidizing (predominantly CO and particles C that have not burned completely). The combustion in the central part of the flame is incomplete: it takes place in a shortage of oxygen, while the temperature varies from hundreds to 1300-1500 K. As the distance from the center of the flame increases the medium becomes more and more oxidizing the temperature increases above 2000 K, and the combustion takes place in a surplus of oxygen, a surplus that depends on the established consumption coefficient of air.

Given the temperature in the deoxidizing zone of the flame, if CO₂, CO, and H^O are

considered from a thermodynamic point of view, then stability decreases from CO₂ to H_jO, so

that CO₂ is the most stable followed by the CO, and fi is the least stable substance. Very

often part of the I ..0 even disintegrates to hydrogen and oxygen. It is known that CO is a strong reducer and combines with oxygen not only when oxygen is uncombined, but also when oxygen is combined. The temperature conditions, as well as the existence of deoxidizing medium (Co and particles C) in the central part of the flame, create favorable conditions for the following reactions while water is brought and insufflated into the same zone:

1) CO + H₂O ^< — > CO₂ + H₂

2) C + H₂O ^<"~ > CO + H_j

3) CO + 0.5 O₂ ^< — > CO₂

4) C + 0.5O₂ ^< — > CO

The oxygen for reactions 3 and 4 comes from the disintegrated water molecules. The light radiation influences the reactions too, and its energy depends on the wavelength in the visible and the invisible part of the spectrum. Thus, a source of light focusing on the porous catalyzing nozzle (achieved through an appropriate wavelength of the light emanated by this source) may influence the reactions taking place on the surface of and in the proximity of the porous catalyzing nozzle. Given the conditions of combustion of industrial fuels, the invention tries to create favorable conditions for reactions 1, 2, 3, and 4 through bringing, insufflating (pulverizing), and disintegrating water steam in the central zone of the flame (the deoxidizing zone of the flame) in order to use the worked off water steam as a highly efficient and ecologically clean fuel. This goal is achieved through a pipeline one of the ends of which ends with a porous catalyzing nozzle. The porous catalyzing nozzle is installed in a way allowing the porous catalyzing nozzle to be in the deoxidizing zone of the flame. The porous catalyzing nozzle plays a key role in the creation of conditions for the complete and quick realization of reactions 1, 2, 3, and 4. The porous catalyzing nozzle is constructed according to the present technologies for porous products, and it made of a catalyst (usually elements with incomplete from inside out ) second electron orbit or their compounds) with a melting point higher than the temperature inside the deoxidizing zone of the flame. The size and the number of the pores in the porous catalyzing nozzle depend on the granule metric composition of the selected catalyst, characteristics that determine the contact (reactionary) surface between the mixed gases and the insufflated water steam. The pressure in the pipeline, as well as in the porous catalyzing nozzle, must be higher than the pressure of the flame in the combustion chamber. The insufflations of water steam into the deoxidizing zone of the flame do not lead to changes in the established regime of combustion of industrial fuels because it does not disturb the overall oxygen balance. It is also possible to insufflate (pulverize) a mixture of water steam and gaseous fuels in different ratios, but in this case, the amount of oxygen (air) needed for the combustion of that additional fuel must be taken into account.

Sample Realization: The porous catalyzing nozzle is fixed to a part of the pipeline, the length of which is about t4 to 5 times the thickness of the thermal insulation of the combustion chamber. The fixation is carried out by one of the known methods, welding, soldering, gluing , thread coupling, bayonet coupling, or flange coupling. The porous catalyzing nozzle can be placed into the deoxidizing zone of the flame according to two methods According to the first method, the worked off water steam is brought by a pipe passing through the jet. According to the second method, the worked off water steam is brought by a pipe passing immediately around the jet. In the case of the sample realization, the second method is considered. During the construction of the thermal insulation, an embrasure (opening) is left nearby the jets. An element with a shape identical to that of the embrasure (opening) is made, so that the opening in that element equals the cross-section of the pipeline. This element is made of thermal insulation material. The pipeline with the porous catalyzing nozzle passes through that element.

This construction makes possible the installation of the pipeline in a way that allows the porous catalyzing nozzle to enter the deoxidizing zone of the flame. In addition, the replacement of the construction is easy and quick. In case of replacement, it is necessary to have a spare element without an opening for the pipeline in order to close entirely the opening in the thermal insulation of the combustion chamber. On the other part of the pipeline that leads to the recuperator situated in the exit flue, monitoring measurement devices for control and maintenance of the pressure are installed after the combustion device used to warm up the worked off water steam. The consumption of water steam depends on the number and dimensions of the pores in the porous catalyzing nozzle (in short, it depends on the granule metric composition of the used catalyst) and on the pressure of the used water steam. Since the porous catalyzing nozzle is suitable for a certain granule metric composition unchanged in the process of exploitation, the consumption of worked off water steam is regulated (changed) by the difference in the pressure of the flame in the combustion chamber and the pressure in the pipeline.

Claims

Claims of the Author(s)

1) A Method for the use of worked off water steam during the combustion of solid fuels, liquid fuels, and gaseous fuels, based on the insufflation (pulverizing) of worked off water steam into the deoxidizing zone (the zone of incomplete combustion) of the flame by a pipeline ending with a porous catalyzing nozzle (appliance) [during the combustion of solid fuels, liquid fuels, and gaseous fuels].

2) A method in accordance with the described'¹ mechanism in the first claim, based on the insufflation (pulverizing) of mixture of worked off water steam and gaseous fuel with ratios of oxygen and carbon from 99: 1 to 50:50 percents.

3) A method in accordance with claim #1 and claim #2, based on the use of a source of light that focuses a sheaf of light on the porous catalyzing , a nozzle that is situated in the deoxidizing zone of the flame.