SK6676Y1 - Heat exchanger exhaust gases - air - Google Patents

Abstract

Heat exchanger exhaust gases - air for melting unit for recovery of waste heat of exhaust gas from the melting unit comprising at least three segments (8) arranged in the three spatial axes, wherein the part of the segments (8) is coiled and the part of the segments (8) is firmly anchored. Through the each segment (8) central passes a flue pipe concentrically located in a rigid housing, forming a cooling spaces around flues, in which are at the ends located the tangential air inlets / outlets. At an exhaust gas inlet (5) is located an output (2) of preheated air and at an exhaust gas outlet (6) is located a cold air inlet (7). In the bending places of the segments (8) are installed the elbows (4) with the inspection openings and in the bending places of the segments (8) are integrated the flexible hose jumpers (1) to the air guiding and the elements (3) to the disbursement and to the flow control, the rotary valves or the sliding closures.

Description

The technical solution generally relates to a flue gas heat exchanger-air heat exchanger design, which recovers the low and medium potential waste heat from the melting units, particularly with high particulate dust in the flue gas. Technical solutions generally belong to the field of engineering, mainly in the metallurgical industry.

BACKGROUND OF THE INVENTION

The use of waste heat from industry is one of the most important tools to reduce energy consumption and eliminate CO ₂ emissions in industry. Several solutions of systems that utilize waste heat from melting aggregates are known. Devices that exchange energy between systems and objects with different parameters are called heat exchangers. In the metallurgical industry, a number of recuperative heat exchangers are used to recover waste heat.

Most of the commercially available heat exchangers hitherto are not designed for use in the heavy metallurgical industry due to the aggressive flue gas environment and their high stickiness, making it impossible to use standard heat exchangers. These shortcomings have evoked the design of a system for recovering heat from flue gases from melting aggregates that would be able to operate even in such an environment taking into account specific requirements. These specific requirements include, in particular, ensuring the simple and efficient cleaning of the heat exchange surfaces from the flue gas deposits and the adaptation of the structure to the simple interchangeability of the main parts coming into contact with the flue gases.

This effort results in a newly created device for recovering heat from the waste heat of the flue gas from the melting unit according to this utility model.

The essence of the technical solution

These drawbacks from the prior art are overcome by the flue gas-air heat exchanger for the melting unit according to this utility model. The system of utilization of flue gas heat from the technological process of melting in the melting aggregate acquires unused heat contained in the flue gas and transfers it to the supply air for natural gas combustion in its own recuperative burner. The essence of the technical solution according to the utility model is that in the flue gas-air heat exchanger, a system of flue gas ducts, which are equipped with a steel jacket, serves to heat the air. This creates a space around the flue gas pipe through which cold air supplied from a tangentially connected fan or blower is forced upstream of the flue gas flow. A fan or blower placed on the floor may blow air directly into the burner and / or the blown air is guided through the cooling spaces around the flue gas ducts, a rigid steel casing lining and flexible hose couplings already pre-heated. This concept is designed so that at the flue gas inlet of the flue gas heat exchanger - air, the outlet of the preheated air is situated and at the flue gas outlet of the flue gas heat exchanger - air there is the inlet of the cold air. The flue gas-air heat exchanger comprises at least three segments arranged in three spatial axes, where a part of the segments is pivotable and a part of the segments is fixedly anchored. Preferably, the two segments are pivotable and one segment is rigidly anchored. This means that even through each segment of the flue gas-air heat exchanger, the flue gas duct is centrally located in a rigid steel housing. This creates cooling spaces around the flue gas ducts in which tangential air stages / outlets are located at the ends. At the bending points of the flue gas pipes, i. j. knees are also installed on the segments themselves. These serve as inspection, respectively. cleaning holes. In the places where the segments are bent, elements for flow control and flow control, swivel flaps or plug-in closures are also included.

The advantages of the flue gas-air heat exchanger for the melting unit according to the invention are evident from the external effects. In particular, the effect of the proposed design is to allow the simple and efficient cleaning of the heat-exchanging surfaces from the flue gas deposits which impair the heat transfer. The design also allows for easy interchangeability of corroded parts that come into contact with the flue gas. Because material research has not revealed a significantly higher resistance to corrosion-resistant steels or cast iron, the way of using affordable materials and replacing them in corrosion wear has been chosen. The specific conditions of the melting aggregates, such as the tilting of the furnace and the existing disposition possibilities of the furnace itself, the surrounding technological equipment and the premises in the production hall have led to all parts of the flue gas heat exchanger system air to be used in the furnace and in the immediate vicinity of the furnace.

BRIEF DESCRIPTION OF THE DRAWINGS

The flue gas heat exchanger - air for the melting unit for utilizing the waste heat of the flue gas from the melting unit remelting secondary aluminum will be more clearly illustrated in the accompanying drawings, where FIG. 1 is a side view of the location of the flue gas-air heat exchanger in the complex of the melting unit. In FIG. 2 shows a solution of the flue gas-air heat exchanger itself. In FIG. 3 is a top view of the location of the flue gas-air heat exchanger in the complex of the melting unit.

It is to be understood that the various embodiments of the invention shown in the individual figures are presented by way of illustration and not by way of limitation of particular embodiments. It is also understood that the various embodiments of the invention shown in the individual figures are made of materials known to those skilled in the art.

Those skilled in the art will find or be able to ascertain, using no more than routine experimentation, equivalent embodiments of the invention. Such equivalents will also fall within the scope of the following protection claims.

Example

In this example of a particular embodiment, a flue gas-air heat exchanger for a melting unit constructed according to a utility model is illustrated in FIG. 1 to 3. It is a heat exchanger system which is located on the furnace and next to the furnace of the melting aggregate with additional supplementary and fastening elements. The flue gases from the furnace of the melting aggregate transfer heat first to the air for their own regenerative burner and then, in one possible embodiment, leave for the chimney. Flue gas - air heat exchanger consists of a system of modules assembled into a functional unit. These are three flue gas pipe segments 8, four elbows 4 with inspection openings, a swivel joint, and other elements 3 such as a flue gas plug, two shut-off flaps, support devices such as brackets and stands and other fasteners. Elbows 4 made of sheet steel are installed in places where the flue gas direction changes by 90 °. On the inside, they are protected against the heat of flue gas by an insulating layer of refractory concrete. One whole wall is an inspection opening, which also serves as a cleaning opening. The opening closure is in the form of a door on the hinges. It is sealed with cord and secured with wedge fuses and wing nuts.

The flue gas ducts are coarse steel pipes, which at the same time have the function of a heat exchange surface to heat the air to the regenerative burner. Due to thermal expansion, they contain telescopic expansion elements sealed with cords and at the beds. They are fastened to the fittings and elbows 4 by flanges and screws.

The space for heated air around the flue gas pipes is formed by thin-walled steel casing pipes mounted on the flue gas pipes in a detachable manner. The three heated air spaces are interconnected by flexible air ducts 1 in series, thus forming a path for a single air flow from the ventilator to the steel pipe continuing into the burner. Air to the flue gas heat exchanger - the air enters tangentially and progresses spirally around the inner flue gas pipe and exits tangentially again. At the flue gas inlet 5, the preheated air outlet 2 is situated, and at the flue gas outlet 6, the cold air inlet 7 is situated.

In the axis of rotation of the furnace, i. j. tilting of the furnace during pouring of the melt is a rotary joint from the flue gas duct. It is of simple construction with axial rotation of the movable part. The seal is a slot and suction effect of the flowing flue gas. For the joint to function properly, it must be positioned exactly in the axis of the furnace tilt pins. On the furnace and on the floor, the exchanger and the flue gas ducts are supported by brackets and stands, which are height adjustable during assembly.

The flue gas flows from the furnace of the melting aggregate through the open cap gradually through the flue gas ducts and elbows. The cold air from the fan behind the blower separately flows through flexible hose couplings 1 through the individual segments 8 of the flue gas heat exchanger - air upstream of the flue gas, thus eliminating assembly inaccuracies but mainly tilting the furnace and the flue gas heat exchanger outlet. furnace led into the burner.

Industrial usability

The flue gas heat exchanger - air for utilizing the waste heat of the flue gases from the melting aggregate remelting secondary aluminum according to this technical solution represents a device usable in the metallurgical industry with sufficient amount of low and medium potential waste heat from the melting aggregates.

Claims (4)

Flue gas heat exchanger - air for a melting plant for recovering the waste heat of a flue gas from a melting plant, characterized in that it consists of at least three segments (8) arranged in three spatial axes, where part of the segments (8) is twistable and 8) is rigidly anchored, with the flue gas pipe centrally extending through each segment (8) concentrically housed in a rigid casing creating cooling spaces around the flue gas ducts in which tangential air stages / outlets are located at the ends; a pre-heated air outlet (2) is situated at the flue gas inlet (5) and a cold air inlet (7) is situated at the flue gas outlet (6). Flue gas heat exchanger - air for a melting plant for utilizing the waste heat of the flue gases from the melting plant according to claim 1, characterized in that it consists of three segments (8) arranged in three spatial axes, wherein the two segments (8) are twistable and one the segment (8) is firmly anchored. Flue gas heat exchanger - air for the melting unit for utilizing the waste heat of the flue gases from the melting unit according to claims 1 to 2, characterized in that elbows (4) with inspection openings are installed at the bends of the segments (8). Flue gas heat exchanger - air for the melting unit for utilizing the waste heat of the flue gases from the melting unit according to at least one of Claims 1 to 3, characterized in that flexible hose ducts (1) for the air conduction and elements (3) for flow control and flow control, swivel flaps or slide shutters.