JPH0429201Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is a waste heat boiler that extracts thermal energy from high-temperature exhaust gas containing a large amount of dust, such as that emitted from an electric arc furnace, and uses it effectively. It is related to.

[Prior art and its problems] Various attempts have been made to recover and effectively use the thermal energy of high-temperature exhaust gas discharged from an arc furnace to save energy. One of them is to provide a boiler in the exhaust gas line as shown in Japanese Patent No. 59-79403. However, since the exhaust gas discharged from the arc furnace contains a large amount of dust that is easily solidified by cooling, there has been a problem that the dust adheres to the inside of the boiler and significantly impairs air permeability in a short period of time.

[Purpose of the invention and means for achieving the same] Therefore, the present invention aims to provide a waste heat boiler that is less likely to cause trouble due to dust adhesion.

In order to achieve this purpose, the waste heat boiler of the present invention has a boiler tube arranged on the inner peripheral surface of the vertical cylinder, and the upper side walls of the vertical cylinder are arranged so that the exhaust gas can collide head-on at the upper part of the vertical cylinder. A pair of exhaust gas inlet ports are provided symmetrically at the positions, and the side wall of the vertical cylinder that continues directly below the exhaust gas inlet ports is formed into an inclined surface shape that narrows downward, and an exhaust port is provided in the lower side wall of the vertical cylinder. It is characterized by having a hopper for discharging dust at the bottom.

[Operation] Exhaust gas entering from both exhaust gas inlets collides head-on at the upper part of the vertical cylinder, and at the same time is radiatively cooled by the boiler tube on the inner circumferential surface. Then, the large particles of dust that are generated then descend directly into the cylinder and are captured by the hopper.

[Example] In the figure, 1 and 1 are an arc furnace, and 2 and 2 are ducts for exhaust gas discharged from this arc furnace, and the ducts are symmetrically provided at opposite positions on the upper side wall of the vertical cylinder 3. The exhaust gas inlets 4, 4 are connected to the exhaust gas inlets 4, 4. The side wall of the vertical cylinder 3 that continues directly below the introduction ports 4, 4 is formed into an inclined surface 5, 5 that narrows downward. 6, 6... are boiler tubes (water tubes) disposed on the inner peripheral surface of the vertical cylinder. Reference numeral 7 indicates an exhaust port provided in the lower side wall of the vertical tube 3, and 8 indicates an exhaust flue. Moreover, 9 is a hopper for discharging dust provided at the bottom of the vertical cylinder 3.

In the exhaust heat boiler configured in this way, the high temperature exhaust gas discharged from the arc furnaces 1, 1 is transferred from the exhaust gas inlets 4, 4 to the vertical tube 3 as shown by the arrows in the figure.
They go inward and collide with each other in the center. This collision causes the fine dust components contained in the exhaust gas to collide with each other in the air. At the same time, the surrounding boiler tubes 6, 6, . . . radiately cool the material to lower the temperature and precipitate large particles of dust. The dust descends directly inside the vertical tube 3 and is deposited on the popper 9. In addition, while the exhaust gas descends in the vertical pipe 3 toward the exhaust port 7, it is further radiatively cooled by the surrounding boiler tube 6, and its sensible heat is transferred to the water or steam in the boiler tube 6, and the exhaust gas generates its own It is discharged into the flue 8 after lowering its temperature.

Note that dust is prevented from sliding down and accumulating on the slopes 5, 5, and the dust accumulated on the hopper 9 is periodically disposed of outside.

[Effects of the invention] As described above, the waste heat boiler of the present invention collides the exhaust gas head-on at the upper part of the vertical cylinder and at the same time cools the exhaust gas radiatively by the surrounding boiler tube, which makes it possible to eliminate large particles of dust. It can be deposited within the vertical cylinder. Since the separated dust can be directly descended inside the vertical cylinder and deposited on the hopper, adhesion of dust to the internal surface of the vertical cylinder and the boiler tube as in the conventional case can be prevented as much as possible. This eliminates the problem of loss of air permeability due to dust adhesion, making it very suitable for heat recovery from dusty exhaust gas such as arc furnace exhaust gas.

[Brief explanation of the drawing]

The drawing is a longitudinal sectional view of a waste heat boiler showing an embodiment of the present invention. 3... Vertical cylinder, 4, 4... Exhaust gas inlet, 5, 5
... Inclined surface, 6 ... Boiler tube, 7 ... Discharge port, 9 ... Dust discharge hopper.

Claims (1)

[Scope of utility model registration request] A boiler tube is arranged on the inner circumferential surface of the vertical cylinder, and a pair of exhaust gas inlets are symmetrically provided at opposing positions on the upper side wall of the vertical cylinder so that the exhaust gas can collide head-on at the upper part of the vertical cylinder. The side wall of the vertical cylinder that continues directly below is formed into an inclined surface shape that narrows downward, and the lower side wall of the vertical cylinder is further provided with an exhaust port, and the bottom of the vertical cylinder is provided with a hopper for discharging dust. Characteristic exhaust heat boiler.