DE586369C - Firing for steam boilers or the like heated with liquid or dusty fuel. - Google Patents

Description

Firing for heated with liquid or powdered fuel Steam boiler o. The like. The object of the invention forms a with liquid or pulverulent fuel. to be operated and with facility to achieve a circular movement of the fuel-air mixture for steam boilers and the like, the known firings are compared with a new and peculiar one Training of the device to achieve the circular movement of the fuel air mixture and proves to be particularly advantageous as a high-performance combustion system.

The progressive increase in the performance of steam boilers and their firing systems has also resulted in a progressive increase in the size of the combustion chambers. This was necessary to avoid unpleasant side effects, such as B. local overheating, strong ash deposits, stab flaming and the like. To prevent. Particularly in steam boiler systems with pulverized coal combustion, such side effects require large combustion chambers. The systems designed in this way, however, become expensive and confusing, and in addition the large dimensions of the combustion chambers can in most cases only partially and incompletely reduce the harmful effects of the accompanying phenomena mentioned. One is therefore even "often forced to forego coal dust firing, which is advantageous per se, if it gives rise to the fear of excessive fly ash, as is the case with systems with artificial drafts, for example, but there is also the risk that, as a result of afterburning in the area of Heating surfaces Damage to these heating surfaces is caused by local overheating or the water cycle is disturbed. It has therefore recently been attempted to achieve a favorable burnout of the fuel and a shortening of the flame paths by trying to set the burning fuel-air mixture in circling motion However, the measures taken so far, especially in the case of hydrocarbon gas generators, have only met a minor degree, especially when the fuel tends to form long flames.

One has z. B. suggested the fuel and the air in more or to be blown into a combustion chamber with a round cross-section in a less tangential direction and in this way to bring about the circular movement. This is inexpedient because the fuel is blown against the chamber wall, which acts as a guide surface should work. In doing so, the living force of the fuel jet is largely destroyed, and coarser components of the fuel can fail from the outset without to be able to come to sufficient combustion. After one for this reason only with proportionately work at a slower pace can, can also not achieve a lively circular movement of the fuel-air mixture and the less coarse components will be prematurely affected by the pulling effect recorded, especially if you blow in additional air from below. Even with these institutions the combustion chamber must therefore be made very high in order to achieve sufficient burnout to achieve the fuel.

Institutions based on similar considerations in which the Guide surface into the interior of the combustion chamber in the form of a cylinder crossing it is laid, - against which fuel and air are blown in a tangential direction, suffer from the same defects and therefore do not give a satisfactory effect.

A proposed device for oil firing, in which a rotatable deflector mounted in the area of (51 nozzles and air or steam nozzles is, does not come for the extension of the burning path with a small flame space in question. The deflector moved by the gas flow, i.e. consuming flow energy can be used to mix oil and air or oil and steam to a certain extent Contribute dimensions, but it can not result in a circular extension of the focal path Induce movement of the mixture.

Equally unsuitable is a device known for grate firing, in which a screw conveyor is provided behind the grate in the gas flue. This in axial Direction of the conveying screw only results in an acceleration of the combustion gases, would even be shortened in the transfer to pulverized coal furnaces and the like the time required for a good burnout. Through the invention the disadvantages of the previously known firing systems are avoided. This is according to the invention achieved in that a rotor is arranged in the combustion chamber by its rotation the burning mixture of combustion air and fuel in and around him circular movement is offset, so that a small flame or combustion chamber large flame path is created and the mixture is completely burned out before it hits the contact heating surfaces.

In this way, an I ', total burning of the fuel in the boiler passes or in the immediate area of heating surfaces.

It is also not to be feared that z. B. with pulverized coal firing coarser parts are thrown against the wall of the combustion chamber by the centrifugal effect and fail prematurely. Such as B. show known dust collector where the dust is collected by impellers and attached to their perimeter along with the air to be conveyed in deposition chambers are to have sufficient acceleration To achieve light goods in the radial direction, specially designed impellers large diameter is required, while in cyclone-type dust collectors large Flow velocities are required and also special facilities Must be taken to avoid entrainment of dust through the central air outlet to prevent. In contrast, the device according to the invention has it without further in the hand to train the rotor in such a way and with such speed itself to let rotate that .the circular movement of the fuel-air mixture in reasonable Limits remain and fuel particles are not ejected.

It is thus possible, by means of the invention, to substantially reduce the fuel consumption better way to use than before and the residual losses of the system as well as the Significantly reduce fly ash emissions. Coal dust firing can therefore also to be used in those cases in which one has hitherto been aware of the same with regard to had to do without the aspects mentioned at the beginning.

Claims (7)

PATENT CLAIMS: e.g. Firing for with liquid or powdery Fuel-heated steam boiler or the like with a device for achieving a circular flow Movement of the fuel-air mixture, characterized in that in the combustion chamber a rotor is installed, the rotation of which causes the burning mixture of combustion air and fuel in with it respectively around. it is moved in a circular motion, so that with a small flame or combustion chamber, a large flame path is created and a complete one Burnout of the mixture can take place before the same on the contact heating surfaces meets. 2. Furnace according to claim i, characterized in that the rotor a-us a roller (f) provided with conveying surfaces (e), the supply of the Fuel and the combustion air can be done in any known manner. 3. Furnace according to claim i, characterized in that the rotor is used as a device for supplying fuel or fuel and combustion air or combustion air trained alone is and from a hollow roller (k) with advantageous wall openings (L) extending tangentially to its axis. ¢. Firing according to claim 3, characterized in that the hollow roller (k) is also hollow Conveyor blades is formed, the latter Duvchgangskanalkanals for the fuel or the combustion air or both. 5. Firing according to claim r to q., characterized in that two or more rotors with the same or different Direction of rotation and with axes of rotation running parallel or at an angle to one another in the combustion chamber are arranged. 6. Furnace according to claim 3 to 5, characterized in that that the drive of the rotor by .the reaction of the or the under pressure in tangential Direction to its axis of rotation emerging operating means takes place or through the same is supported. 7. Firing according to claim r to 6, characterized in that they are housed in a combustion gas chamber adjoining the main combustion chamber is.