DE3404277A1 - Steam production plant with a flue gas cleaning device - Google Patents

Abstract

For a steam production plant with a flue gas cleaning device, a steam producer is proposed as a single-flue boiler 1 with an upper horizontal gas outlet 2, and with a device for spraying in NH3, a centrifugal dust separator 8, a catalytic nitrogen oxide reactor 5 with dust blowers 5a, and a rotary air preheater 6 with a vertical axis of rotation and adjoined by an electrostatic filter 7 with a horizontal gas passage, arranged in succession in the downward-leading flue 3. The usually empty downward-leading flue is thus optimally used for preliminary dust removal and for elimination of the nitrogen oxides. <IMAGE>

Description

Steam generation system with exhaust gas cleaning device

The invention relates to a steam generation system with an exhaust gas purification device, consisting essentially of a boiler, air preheater and electrostatic precipitator.

In such systems, there is generally a reduction in operating costs an increase in investment costs compared to and vice versa. In terms of a possible Economic provision of electrical energy is therefore required more carefully Considerations in order to find an optimal compromise between investment and operating costs get.

These considerations are made considerably more difficult by the rules for exhaust gas cleaning. While the electrostatic dust separation has become the classic Exhaust gas cleaning processes are to include facilities for desulfurization and for the elimination of nitrogen oxides is still relatively rare. In addition to procedural Questions arise again and again, problems of constructive training and spatial Arrangement of additional pieces of equipment. The latter, like the entire system, to be interpreted in such a way that, on the one hand, the respective legal requirements are met, on the other hand, however, in terms of process and plant costs, competitiveness preserved.

The invention is based on the object in a steam generation system of the type mentioned above, a device for eliminating nitrogen oxides in the exhaust gas to be integrated in a way that saves costs and space.

This object is achieved according to the invention in that as a steam generator a known draw-in boiler with an upper horizontal gas outlet was selected that in the downward throttle cable one after the other a device for injecting of NH3, a catalytic nitrogen oxide reactor with dust blower and a rotary air preheater are arranged with a vertical axis of rotation and that then an electrostatic precipitator is provided with a horizontal gas passage.

In a further development of the inventive idea it is also provided that between the device for injecting NH3 and the dust blower of the catalytic Nitric oxide reactor a centrifugal dust collector is provided.

Including the proposed arrangement of the nitrogen oxide reactor Ancillary units and, if necessary, a centrifugal dust separator in front of the rotary air preheater in the second throttle cable running from top to bottom, not only are the pressure losses reduced to a minimum, but also the space requirements and the cost of materials, which saves operating and system costs compared to comparable systems. This applies to new systems, but also especially when retrofitting into existing ones Investments.

Further details of the invention are based on the in the figures illustrated embodiments explained in more detail: Figure 1 shows an overall view the steam generation plant.

Figure 2 shows a section through the downward throttle cable.

In Figure 1, a draw-in boiler 1 of conventional design is shown is suspended in a support frame 9 and an upper horizontal gas outlet 2 owns. In the downward throttle cable 3, which rests on a further support frame 10, are a device for injecting NH3 one after the other in the direction of gas flow, a centrifugal dust collector, a catalytic nitrogen oxide reactor with a dust blower and a rotary air preheater 6 arranged with a vertical axis of rotation. From the rotary air preheater 6, the gas flow is passed into an electrostatic precipitator 7 with a horizontal gas passage and finally released into the chimney 12 by means of an induced draft fan 11. This arrangement of the system parts to be connected downstream of the boiler meet all of the requirements set out at the beginning particularly useful because the largely unused in conventional systems, second throttle cable leading downwards not only to accommodate the rotary air preheater 6, but also to arrange all necessary for the removal of nitrogen oxides Facilities is used. It is therefore in the smallest possible space and in the shortest possible time Gas path accommodates all functionally required system parts.

In Figure 2, the upper part of the downward throttle cable 3 is still shown once enlarged in section. The from boiler 1 over the upper horizontal Gas outlet 2 incoming gases first pass a device 4 for injection of NH3 and then a centrifugal dust separator 8, to which a dust chute 8a and a discharge 8b belongs. The gases then pass into a multi-stage Nitrogen oxide reactor 5 with an upstream dust '' blower 5a and then in the rotary air preheater. It is readily apparent that, according to the invention, the second gas cable, which is empty per se 3 now in a meaningful way for a certain pre-dedusting by means of centrifugal force and used to eliminate nitrogen oxides.

Claims (2)

PATENT CLAIMS @ Steam generation system with exhaust gas cleaning device, essentially consisting of boiler, air preheater and electrostatic precipitator, characterized in that that the steam generator from a draw-in boiler (1) with an upper horizontal gas outlet (2) consists that in the downward throttle cable (3) one after the other a device (4) for injecting NH3, a catalytic nitrogen oxide reactor (5) with dust blower (5a) and a rotary air preheater (6) are arranged with a vertical axis of rotation and that then an electrostatic precipitator (7) with a horizontal gas passage is provided is. 2. Steam generating system according to claim 1, characterized in that that between the device (4) for injecting NH3 and the dust blower (5a) of the catalytic nitrogen oxide reactor (5) a centrifugal dust collector (8) is provided is.