Fusion heat recovery and combustion gases filtering system with electric power production

Abstract: The system comprises providing every oven (1) used in a ceramic enamelling plant with an operative unit (3) that works with an exchanger (4) and a filter (5) that allows most of the waste products entrained by the fumes to be recovered, sent back to the oven (1) and hence be recycled. The operative units (3) of the various ovens (1), in accordance with the improvements, are in direct communication and in open circuit with an output exchanger (9) associated with a turbogenerator (10), using air as the heat transmission fluid. The turbogenerator (10) includes a secondary circuit (11) of the exchanger (9), using a vapour fluid to drive a turbine (12) that in turn drives an alternator (13) for generating electric power.

Description: OBJECT OF THE INVENTION The present invention relates to a number of improvements made to a heat recovery and gases filtering system at the outputs from industrial fusion ovens, which system allows both high yields to be obtained in the production of electric power and fumes to be perfectly scrubbed, the waste products obtained being moreover recyclable. The process claimed in the main patent of invention is especially applicable to the glass-ceramics and chemical industry but applies equally in any other field requiring a similar level of performance. This system uses a fluid, preferably water, which equally includes a high molecular mass organic fluid, as a heat exchanging product, flowing in a second circuit to drive a turbine and, through the latter, an appropriate alternator generating electric power. The improvements of the invention are based upon the use of air as the heat transmission fluid, and vapour as the fluid in the second circuit for driving the generator. BACKGROUND OF THE INVENTION The heat recovery and combustion gases filtering system described in main patent of invention number 9302634, and especially applicable to ceramic enamelling plants, is devised to resolve the loss of waste products entrained by the exhaust gases, in such a way that, based upon the subject system, on the one hand, the waste products obtained from filtering can be recycled, and, on the other, energy can be made the most of. To that end, said system subject of the main patent of invention provides an operative filtering unit for each of the ovens used in the plant, working with the respective heat exchanger to allow such filtering to be carried out under the best possible conditions, such operative unit being located over the oven exhaust passage as such in order for hot water to be obtained using such exchanger, at a temperature ranging between 90 and 150°C, as well as cold fumes that allow flexible bag or cap filters to be used, from which waste products are obtained that are recyclable back to a specific and unitary oven, since originating therein. The various heat exchangers working with the respective ovens are interconnected in parallel and associated with a joint circuit provided with a second heat exchanger that relates the said circuit, which is preferably a water circuit, to a second circuit through which a high molecular mass organic fluid flows, in order to drive a turbine and, through the same, a respective alternator generating electric power, i.e. constituting an organic cycle turbogenerator. In short, in this system subject of the main patent of invention, a filter is provided at the output from each oven for the fumes, after such fumes have passed through a heat exchanger, a special feature being that the heat exchanger is associated with a heat exchanging circuit, the fluid in which circuit is preferably water, the water circuit being the meeting point for all the operative units of the various ovens, each unit comprising the respective filter and the heat exchanger, and a manifold and an aspirator expediting the flow of gases. The water circuit is associated with a second output exchanger through which the water heated in the input exchangers to a temperature ranging between 90 and 150°C, transmits its heat to a turbogenerator, with a circuit that has a high molecular mass organic fluid for driving a turbine with which an alternator is associated for the generation of output electric current. DESCRIPTION OF THE INVENTION The improvements of the invention are specifically applicable to the system described in the previous section, i.e. to the system claimed in main patent of invention number 9302634, the first improvement being based on the use of air instead of water as the heat transmission fluid, which is much cheaper and allows closed cooling circuits to be eliminated, which means that an open circuit may be used. Furthermore, the use of air as the heat transmission fluid is not only less expensive than water, oil or other liquid fluids, but moreover allows no waste products whatsoever to be created. It is also noteworthy that the use of air as fluid allows the circuit at which the various exchangers of the units associated with each of the ovens meet to be eliminated, thereby avoiding a closed circuit return from the output exchanger to the input exchanger, as the case may be, for if air is used as the heat fluid, the discharge will take place directly to the atmosphere. Another of the improvements lies in that the circuit in which the respective turbogenerator is integrated makes use of a vapour fluid or an organic fluid. DESCRIPTION OF THE DRAWINGS In order to provide a fuller description and contribute to a complete understanding of the characteristics of the invention, in accordance with a preferred practical embodiment thereof, a sheet of drawings is attached as an integral part of the description which, while purely illustrative and not fully comprehensive, shows the following: Figure 1.- Is a diagram showing the fusion heat recovery and combustion gases filtering system, with electric power production, wherein two ovens are used and wherein the fluid used for heat transmission is a liquid such as water or oil. Figure 2.- Is another diagrammatic representation of the system in accordance with the improvements of the present addition certificate, i.e. using air as the heat transmission fluid, thereby eliminating the return circuit, for the air will be evacuated directly to the atmosphere. PREFERRED EMBODIMENT OF THE INVENTION Bearing in mind that the diagram of figure 1 represents a system in accordance with the description given in main patent of invention number 9302634, and that figure 2 has been drawn with the improvements subject of the present addition certificate, the characteristics of the former should usefully be recalled to see where the improvements actually lie. In this sense, figure 1 shows a variable number of ovens (1-1') the exhaust passage (2) of which is provided for every oven (1) with an operative unit (3) working with a heat exchanger (4) to cool the gases or fumes down to a suitable temperature in order for the same to be filtered as best as possible in a self-cleaning textile bag or cap filter (5) in such a way that the waste products extracted by the filter (5) can reach a manifold (6) from which they can again move into the oven (1) to be recycled, according to the arrow shown in the figure, the filter (5) working with a conventional aspirator (7) that expedites the flow of the gases. The exchanger (4) is associated with a circuit (8), preferably a water circuit, although oil or any other heat transmission fluid can also be used, the operative units (3) of the various ovens (1) all meeting at this water circuit (8), the water circuit being associated with a second output exchanger (9) through which the water heated in the input exchangers (4) to a temperature ranging between 90 and 150°C transmits its heat to a turbogenerator (10), with a circuit (11) that has a high molecular mass organic fluid to drive a turbine (12) with which an alternator (13) is associated for the generation of output electric current (14). The system in accordance with the improvements, represented in figure 2, uses air in lieu of water or oil as the heat transmission fluid. In other words, gases from the ovens (1-1') flow through the exchangers (4), then through the filters (5), associated with the aspirator (7) which expedites the flow of such gases, which components are established in each operative unit (3) as explained hereinbefore, and waste products reach a manifold (6) from which they can again move back into the respective oven, as explained hereinbefore. Now then, in accordance with the improvements, air will be used as the heat transmission fluid, in which case there is neither a return nor a circuit as identified in figure 1 with the reference numeral (8), which means that only components such as valves and other elements (8') are included for gases to flow from the exchangers (4) to the output exchanger (9). In other words, in accordance with the improvements, air is used as the heat transmission fluid and the temperature to be attained will range between 90 and 400°C in lieu of between 90 and 150°C referred to hereinbefore. As explained before, since air is used as the heat fluid, the closed circuit return from the output exchanger (9) will no longer be required, for the air will be discharged directly to the atmosphere. On the other hand, it is noteworthy that the turbogenerator (10) circuit uses a water vapour fluid, although a high molecular mass organic fluid can also be used, depending in each case on the temperature and characteristics of the heat fluid chosen. With the system in accordance with the improvements, not only may the powder contained in the exhaust gases from every oven (1) be separated and hence be used in the relevant oven, thereby increasing frit production and drastically reducing the amount of waste powder to be disposed of, but moreover the plant will be more economical, for on the one hand the fluid used costs no money and on the other the closed cooling circuits may be eliminated and an open circuit maintained, and further a more economical maintenance is achieved since air is used and no waste products will be created in the passages. Another element that helps reduce the economical cost lies in that the circuit in which the system units (3) all used to meet is eliminated in this case and the fluid passes directly, through the components (8'), to the output exchanger (9).

Claims: A fusion heat recovery and combustion gases filtering system with electric power production, which is especially applicable to ceramic enamelling plants and the like, where several ovens are used with various kinds of enamel, and every oven (1) is provided with an operative filtering unit (3) working with a heat exchanger (4) that cools the fumes, a filter (5) wherein the powdered enamel is recovered to be sent back to the oven (1) and hence recycled, the operative units (3) being connected to a second output exchanger (9) transmitting the heat absorbed to a turbogenerator circuit (10, 11) (10) in which a turbine (12) is provided to drive an alternator (13) that generates the electric power into which the heat energy extracted from the fumes is transformed as they leave the ovens (1), characterised in that the heat transmission fluid is air, the air being established in an open circuit with direct communication between the exchangers (4) and the output exchanger (9) and exiting directly to the atmosphere; the turbogenerator (10) circuit being provided to use a vapour fluid or a high molecular mass organic fluid. A fusion heat recovery and combustion gases filtering system with electric power production, as in claim 1, characterised in that the heat transmission fluid heated in the exchangers (4) reaches a temperature ranging between 90 and 400°C.

Inventors: NEBOT APARICI ANTONIO, NEBOT APARICI, ANTONIO, Nebot Aparici, Antonio, Colorobbia Espana, S.A.
Applicants: COLOROBBIA ESPANA SA, COLOROBBIA ESPANA, S.A.
Application year: 1997
Main classification: F01K3
IPC codes: F27D17, F01K3, C03B5