Method to process fumes and relative device

Details Method to process fumes and relative device Method to process fumes and relative device

1999-10-20

2000-12-19

Hoang, Tu Ba

Industrial electric heating furnaces

Environmental control

Arc furnace

373 8, 373 80, F27D 1700

Patent

active

06163560&

DESCRIPTION:

BRIEF SUMMARY
FIELD OF APPLICATION

This invention concerns a method to process fumes and the device which achieves the method.
The invention is applied in the field of steel production to perform a preliminary processing of the fumes discharged from the furnace before they are sent to the filtering and purification plants and discharged into the atmosphere.
The invention is applied particularly, though not exclusively, in processing fumes used to pre-heat scrap which is to be loaded into the furnaces.
The invention optimizes the combustion of CO and volatile and aromatic substances contained in the fumes, thus rendering the work of the final purification plants and discharge into the atmosphere less onerous.
The invention can be used both in completely new plants for the processing of fumes, appropriately laid out, and also in existing plants by revamping.


STATE OF THE ART

The state of the art covers steel production plants where the furnaces are loaded with scrap which has been pre-heated by the heat of the fumes discharged from the furnaces themselves during the melting cycles, through the aperture, or fourth hole, on the roof of the furnace.
Among the various systems to pre-heat the scrap, it is known to convey the fumes discharged from the furnace directly inside the baskets used to load the scrap by means of the appropriate pipes which are connected on one side to the fourth hole of the furnace and which cooperate on the other side with an inlet aperture made in the structure of the baskets or in their cover. The baskets are also equipped with at least one outlet aperture through which the fumes are discharged and conveyed to the purification plants and discharged into the atmosphere.
A first disadvantage of this method is that the fumes leaving the baskets, or leaving the furnace if there is no pre-heating of the scrap, travel at extremely high speed.
The high speed of the fumes prevents the purification and discharge system from functioning efficiently; the powders, particles and other polluting substances contained in the fumes are therefore retained and filtered only to a limited extent.
The high speed of the fumes, moreover, causes a premature wear of the components, particularly the filter means and the cooling means for the pipes, which are included in such plants to purify and discharge the fumes.
Furthermore, the high speed of the fumes also prevents the post-combustion processes, which may be included upstream of the purification and processing plants, from performing efficiently.
It should be considered that, in plants where the scrap is pre-heated, the fumes, which are already highly pollutant in themselves as they leave the furnaces, absorb further powders and noxious and pollutant substances as they pass through the scrap contained in the baskets.
Consequently, the filter means of the plants to purify and discharge the fumes are always working under extreme conditions, and need frequent cleaning, maintenance and/or replacement; this causes frequent and prolonged downtimes in the melting cycles and therefore a reduced productivity of the whole steel plant.
In order to limit the speed of the fumes before they are sent to the purification and discharge plants, various solutions have been proposed, but they have not shown themselves to be at all functional and/or they are very expensive and/or not very efficient.
These solutions are substantially based only on particular geometric conformations of the conduits which convey the fumes; they therefore only manage to obtain satisfactory results at the expense of construction complexity and costs, of management and maintenance.
FR-A-2105394 shows a device to process the gases arriving from a melting plant in which there are means at the inlet to induce a cyclonic development in the gases and tangential burners arranged against the current with regards to the direction of rotation of the fumes.
This device does not make it possible to reduce the speed of the fumes between the inlet and the outlet, so that in any case the processing is unsatisfactory.
U.S. P

REFERENCES:
patent: 3843329 (1974-10-01), Longley
patent: 3898317 (1975-08-01), Hemsath et al.
patent: 4124681 (1978-11-01), Reed et al.
patent: 4437186 (1984-03-01), Inai
patent: 4526678 (1985-07-01), Myhren et al.
patent: 4611339 (1986-09-01), Saitoh
patent: 4867676 (1989-09-01), Buzetzki
patent: 5265117 (1993-11-01), Pernet et al.
patent: 5787108 (1998-07-01), Pavlicevic et al.

Affiliated with

Also associated with

Rating

Method to process fumes and relative device does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method to process fumes and relative device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method to process fumes and relative device will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-276390