Technical field

The invention relates generally to the design solution of the heat exchange equipment combustion products - water of a smelting aggregate, which recovers low and medium potential waste heat from smelting aggregates particularly those with high drift of dust particles contained in the exhaust gas. The invention pertains generally to the field of engineering, mostly to the steel industry.

The prior art

Use of industrial waste heat is one of the most important tools for reduction of energy consumption and elimination of C0 ₂ emissions in industry. There is a number of system solutions that use waste heat from smelting aggregates. Devices that are used to exchange energy between systems and objects with different parameters are known as heat exchangers. In the steel industry a variety of recuperative heat exchangers is used for the waste heat recovery.

The bulk of currently commercially available heat exchangers is designed for use in heavy steel industry, given the aggressive environment of flue gases and their high adhesiveness, which excludes the use of standard heat exchangers. Aforementioned drawbacks evoked a proposal of a system for recovering heat from flue gases from smelting aggregates, which would be able to work even in such environment, taking into account the specific requirements. These specific requirements can be classified mainly as provision of a simple and effective cleanability of heat exchanging surfaces from the flue gas deposits and adaptation of design to simple interchangeability of the main parts in contact with the flue gases.

The result of this effort is the newly created device designed for recovery of heat from the flue gas waste heat of the smelting aggregate.

Summary of the invention

According to the present invention the heat exchange equipment combustion products - water eliminates the above-mentioned drawbacks of the prior art. The system using the heat from the flue gases of a technological process of smelting in a smelting aggregate receives waste heat contained in the flue gases and transfers it to the plant energy system for water heating. The essence of the invention of the heat exchange equipment combustion products - water used to heat the hot water with a closed water circuit according to the invention lies in the fact that it consists of a vertical flue gas chamber with a flue inlet at the bottom of the flue chamber and a flue gas outlet to the chimney in the upper part of the flue chamber, whereby there is a horizontally layered system of segments with field pipes for the flow of heated water. Distributions of segments with field pipes are led to one outer wall of the flue chamber. System of segments with field tubes is provided with an upper cool water inlet and lower hot water outlet. On one side, the segments are provided with a first fluid chamber and the second fluid chamber located behind the first one. A set of internal tubes extends from the first fluid chamber with spaces between them, which in turn pass across the second fluid chamber up to the end of the segments. Outer tubes with larger diameter leading into the second fluid chamber are put on the internal pipes. The distal end of the outer tubes is closed. The first fluid chambers and a second fluid chambers of individual superimposed segments are connected by interconnecting elements. The upper cool water inlet is guided to the segments in two parallel branches. Due to assembly and disassembly, field tubes are divided into segments, allowing their easy replacement in case of a failure. Flue gas chamber is accessible from three sides via openable doors allowing easy and efficient cleaning. Flue gas and water flow is controlled by flaps, gate valves and valves controlled by an automatic control system. If necessary, they can be controlled manually. Flow of water in the field tubes can occur in two ways. In the first way, the water flows via internal diameter at the end of the inner tube, where the water flow reverses and the water flows back via cross-section of the annulus defined by the diameter of the outer tube. Field tubes with functional spaces for the flue gas flow fill the entire cross-section of the flue chamber. Flue gas flows perpendicularly, i.e. transversely to the field tubes arranged within a segment into a set. The segments are interconnected by interconnecting elements, e.g. hoses, so that the water flowing from the inlet to the heat exchange equipment combustion products - water flows parallelly in two branches to the outlet from the heat exchange equipment combustion products - water. A cleaning opening is located in the lower area of the flue gas inlet.

Benefits of the heat exchange equipment combustion products - water for the smelting aggregate according to the invention result from the effects which are reflected in operation. The effects consist mainly in the fact that the designed construction allows for easy and efficient cleaning of the heat transfer surfaces from flue gas deposits which impair heat transfer. The design also allows for easy interchangeability of corroded parts that come into contact with the flue gases. As the research of materials demonstrated significantly higher corrosion resistance of steel or cast iron, we chose to use affordable materials and possibility of their replacement in case of corrosion. Specific conditions of smelting aggregates such as furnace tilting and existing dispositional options of the furnace itself, the surrounding technological equipment and areas in the production hall led to the installation of all parts of a heat exchange equipment combustion products - air for flue gas waste heat recovery from the smelting unit on the furnace and in the immediate vicinity of the furnace.

Description of drawings

The heat exchange equipment combustion products - water for the smelting aggregate for flue gas waste heat recovery from the smelting aggregate, recasting secondary aluminium, will be explained in more detail in the accompanying drawings, in which Fig. 1 demonstrates an axonometric view of the comprehensive solution of heat exchange equipment combustion products - water. Fig. 2 shows a solution of one segment with field tubes of the heat exchange equipment combustion products - water system. Fig. 3 shows a side view of the solution of interconnection of segments by field tubes. Fig. 4 shows in two side views a system solution of the heat exchange equipment combustion products - water.

It is understood that the various implementations of the invention shown in the various figures are represented for illustration and not as limitation to specific implementation. It is also understood that the various implementations of the invention shown in the various figures are constructed of materials known to the professionals skilled in the art.

Using no more than routine experimentation, professionals skilled in the art shall find or shall be able to ascertain equivalent implementations of the invention. Such equivalents shall also fall within the scope of the following claims.

Example of implementation

This example of a specific implementation describes a heat exchange equipment combustion products - water for the smelting aggregate constructed in accordance with the invention schematically shown in Fig. 1 to 4.

It is a system of heat exchangers, which is located near the furnace of the smelting aggregate. Flue gases from the furnace of the smelting aggregate transmit heat first to the air for its own recuperative burner, and then to the water into the boiler for heating and heating of domestic hot water, and then they escape to the chimney. Heat exchange equipment combustion products - water consists of a vertical flue gas chamber 1 with a flue inlet 2 at the bottom of the flue chamber 1 and a flue gas outlet 3 to the chimney in the upper part of the flue chamber L In the flue gas chamber J_, there is a horizontally layered system of segments 4 with field pipes for the flow of heated water. Distributions 5 of segments 4 with field pipes are led to one outer wall of the flue chamber L System of segments 4 with field tubes is provided with an upper cool water inlet 6 and lower hot water outlet 7. On one side, the segments 4 are provided with a first fluid chamber 8 and the second fluid chamber 9 located behind the first one. A set of internal tubes J extends from the first fluid chamber 8 with spaces between them, which in turn pass across the second fluid chamber 9 up to the end of the segments 4. Outer tubes Π. with larger diameter leading into the second fluid chamber 9 are put on the internal pipes 10. The distal end of the outer tubes ϋ is closed. The first fluid chambers 8 and second fluid chambers 9 of individual superimposed segments 4 are connected by interconnecting elements 12. The upper cool water inlet 6 is guided to the segments 4 in two parallel branches. Due to assembly and disassembly, field tubes are divided into segments 4, allowing their easy replacement in case of a failure. Flue gas chamber I is accessible from three sides via openable doors allowing easy and efficient cleaning. Flue gas and water flow is controlled by flaps, gate valves and valves controlled by an automatic control system. If necessary, they can be controlled manually. Flow of water in the field tubes can occur in two ways. In the first way, the water flows via internal diameter at the end of the inner tube 10, where the water flow reverses and the water flows back via cross-section of the annulus defined by the diameter of the outer tube Π_· In the second way, the water flows via cross-section of the annulus defined by the diameter of the outer tube J_l , there, the water flow reverses and the water flows back via internal diameter of the inner tube 10. Field tubes with functional spaces for the flue gas flow fill the entire cross-section of the flue chamber L Flue gas flows perpendicularly, i.e. transversely to the field tubes arranged within a segment 4 into a set. The segments 4 are interconnected by interconnecting elements 12, e.g. hoses, so that the water flowing from the inlet to the heat exchange equipment combustion products - water flows parallelly in two branches to the outlet from the heat exchange equipment combustion products - water. A cleaning opening is located in the lower area of the flue gas inlet 2.

Distributions 5 of the segments 4 with field tubes are guided so that the upper cool water inlet 6 is led to the second fluid chamber 9 of segment 4 with field tubes of the highest level via connecting elements 12, as well as to the second level of the second fluid chamber 9 of the segment 4 with field tubes. The first fluid chamber 8 of the segment 4_with field tubes of the highest first level is connected via connecting element 12 to the first fluid chamber 8 of the segment 4 with field tubes of the third level, while the first fluid chamber 8 of the segment 4 with field tubes of the second level is connected via connecting element 12 to the first fluid chamber 8 of the segment 4 with field tubes of the fourth level. The second fluid chamber 9 of the segment 4 with field tubes of the third level is connected via connecting element 12 to the second fluid chamber 9 of the segment 4 with field tubes of the fifth level, and the second fluid chamber 9 of the field tubes of the fourth level is connected via connecting element 12 to the second fluid chamber 9 of the segment 4 with field tubes of the sixth level, which then continues up to the last level of the system of segments 4 with field tubes.

Industrial use

Heat exchange equipment combustion products - water for flue gas waste heat recovery from the smelting aggregate, recasting secondary aluminium, according to this invention, is a device usable in the steel industry with a sufficient amount of low and intermediate potential waste heat from the smelting aggregates particularly those with high drift of dust particles contained in the exhaust gas.