JPS6214203B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an exhaust heat recovery device for a copper smelting converter.

The converter used to produce blister copper, which is mainly composed of metallic copper, by air oxidizing pine, which is a sulfide mainly composed of copper and iron, generates high concentrations of SO ₂ and dust during operation. Containing high temperature exhaust gas is generated. Normally, such exhaust gas is used for sulfuric acid production after coarse dust in the exhaust gas is removed in a dust chamber installed at the converter exhaust gas outlet, and fine dust is removed using a high-temperature cottle and subsequent various purification devices. It is sent to the process. The exhaust gas discharged from the dust chamber at this time is a high-temperature gas of about 700 to 800°C, and the gas temperature must be lowered to about 300 to 400°C before being introduced into the high-temperature chamber. Usually, methods such as dilution with air or spraying water into the gas are used as means for cooling the exhaust gas, but these methods are not preferred in terms of an increase in the amount of gas and heat loss.

It is considered that the most desirable exhaust gas cooling means is to install a boiler for exhaust heat recovery between the converter and the high-temperature kettle because it does not increase the amount of gas and can also recover exhaust heat. Conventionally, an exhaust heat recovery device using this method has been proposed and is actually in operation, but in such a conventional device, one boiler is installed for each converter.

Basically, converters are operated in a batch manner, and the operating time is intermittent, and the net operating time for each furnace is short, so the operating rate of the boiler is extremely low. Furthermore, as mentioned above, the exhaust gas from the converter contains a high concentration of SO ₂ and dust, so these corrosive dusts adhere to the boiler tube, and when the boiler cools down due to the shutdown of the converter, the boiler tube There was a risk of corrosion. In order to solve this problem, conventionally, a heat-retaining means was required to keep the outer surface temperature of the boiler tube above the dew point even if the operation of the converter was stopped.

Furthermore, even when a converter is in operation, its operation consists of a production period and a copper production period, and before and after each period there is a wind stop for charging other raw materials or discharging products such as blister copper. Moreover, since there is a wind stoppage due to the time cycle, in addition to the short net operating time as mentioned above, starting and stopping are frequently repeated. Since converter exhaust gas contains high concentration of SO ₂ and dust,
It is necessary to prevent gas leakage from around the converter by always starting gas suction before starting the furnace and stopping gas suction after the furnace has stopped. Therefore, a large amount of cold air is introduced into the boiler immediately before the converter starts and after the converter stops. In particular, when a converter starts, a large amount of cold air is introduced into the boiler, followed by high-temperature gas, which causes the boiler temperature to change suddenly and the water level in the boiler shell to fluctuate significantly. The conditions were extremely poor. In addition, once the inside of the boiler has been cooled by introducing a large amount of cold air, it takes time to recover the amount of steam and pressure generated even after introducing high-temperature gas.
It was completely impossible to use the steam generated from the converter boiler for power generation.

Therefore, the main object of the present invention is to realize a high rate of waste heat recovery with the minimum number of installed boilers in an exhaust heat recovery device for a copper smelting converter including a two-furnace simultaneous blowing converter. It is in.

Another object of the present invention is to increase the efficiency of a boiler installed in an exhaust heat recovery device for a copper smelting converter including a two-furnace simultaneous blowing converter.

Another object of the present invention is to maintain heat of the boiler tube while the converter is not in operation for the purpose of preventing corrosion of the boiler tube in an exhaust heat recovery device for a copper smelting converter including a two-furnace simultaneous blowing converter. There are things that make it unnecessary.

Another object of the present invention is to provide an exhaust heat recovery system for a copper smelting converter including a two-furnace simultaneous blowing converter, to reduce boiler cooling caused by cold air introduced at the start and stop of the converter and the adverse effects thereof. This makes boiler management easier, thereby enabling stable steam generation.
The purpose is to enable the steam generated by the converter boiler to be used for power generation.

According to the present invention, an exhaust heat recovery device for a copper smelting converter includes a common pipe on the inlet side and outlet side for communicating in parallel two or more boilers each having a control valve at the inlet and outlet. A plurality of converters having two or more furnaces capable of simultaneous blowing operation of two furnaces are connected to a portion between the control valves at the inlet of each of the boilers of each of the common pipes, and each of the boilers of each of the common pipes An exhaust gas conduit is connected to a portion between the control valves at the outlet, and the connection position of the exhaust gas conduit and the control valve at each boiler outlet are connected to the portion of each common pipe between the control valves at the boiler inlet. The intermediate portion and the intermediate portion are connected by a bypass conduit having a control valve provided in the intermediate portion.

With this configuration, the present invention provides novel effects as listed below.

Each common tube provides an annular flow path for the exhaust gas from the converter to the exhaust gas conduit, reducing the resistance in the tube for said exhaust gas. This reduces the power cost for sending the exhaust gas and also makes it possible to reduce the amount of free air that enters the pipe.

Since the internal resistance of exhaust gas is small, it is possible to use small diameter pipes and reduce equipment costs.

By combining the opening and closing of the control valves installed at the inlet and outlet of each boiler and the control valves installed in each bypass pipe, only cold air is supplied to the boiler when one furnace is stopped in a two-furnace simultaneous blowing operation. This makes it possible to avoid the inflow of water, eliminate boiler cooling and its accompanying negative effects, and enable stable steam generation from the boiler.

Next, the exhaust heat recovery device for a copper smelting converter according to the present invention will be described in detail with reference to the drawings.

Generally, multiple converter furnaces for copper smelting are installed, in this example six converters 2a, 2b, 2c, 2d, 2e, and 2f are installed, two of which are idled for furnace repair or as a reserve furnace, and the other four converters are is configured to operate. Six converters 2a, 2b, 2c, 2d, 2e and 2f
are dust chambers 4a, 4b, 4c, 4d, respectively.
4e and 4f, and coarse dust in the converter exhaust gas is removed by the dust chamber.

Each dust chamber 4a, 4b, 4c, 4d, 4
The outlets e and 4f are interconnected by a common conduit 30. The common line 30 is connected to the inlets of boilers 26 and 28, which in this example are two, fewer than the number of converters. The flue or flue gas outlet of each boiler 26 and 28 is interconnected by a line 32 and communicated by a line 34 to a hot cottle 36. Although two high-temperature hotterrels 36 are provided in this embodiment, the present invention is not limited to this.

The converter exhaust gas from which particulate dust has been removed in the high-temperature cottle 36 is sent to a normal sulfuric acid manufacturing process via a pipe 38.

In this embodiment, a bypass pipe 42 and a bypass pipe 42 are provided between the common pipes 30 and 32 to allow the converter exhaust gas to flow directly from the common pipe 30 to the flue outlet pipe 32 without going through the boilers 26 and 28. 44 are provided. Valves 46,4 are provided at the inlet and outlet of the boilers 26 and 28 and at the bypass lines 42 and 44.
8, 50, 52, 54 and 56 are arranged.

Next, the operation of the exhaust heat recovery device configured as described above will be explained.

As mentioned above, if four of the converters in the series are in operation, two of them are in the process of blowing air. To be more specific, one unit is in the copper production stage, the other is in the production stage, and the other two are shut down due to loading raw materials, discharging output, or waiting for operation in the time cycle. There is.

In such a situation, ie, when two converters are co-blowing, valves 54 and 56 are closed and all other valves are open. Therefore, the hot exhaust gas from the converter 2 flows from the dust chamber 4 into the common line 30 and then into the boilers 26 and 2.
8 to the conduits 32, 34.

The hot exhaust gas from the dust chamber 4 is heat exchanged in the boilers 26 and 28 and is therefore transferred to the pipe 32.
The temperature of the exhaust gas fed to the high-temperature cottle 36 via 34 and 34 is reduced to about 300°C to 400°C. On the other hand, high-temperature, high-pressure steam generated in the boilers 26 and 28 is fed, for example, to a power generation turbine 60.

On the other hand, one of the converters in the process of blowing air was producing copper or copper.
When stopping due to the end of the period, valves 46 and 4
8 or 50 and 52 are closed and valves 54 or 56 are open. Therefore, the exhaust gas from the dust chamber whose temperature has dropped due to the shutdown of the converter operation is not introduced into the boiler 26 or 28.
Bypass line 42 or 44 and lines 32, 3
4 into the hot cottle 36.

Also, immediately before the converter 2 is started, the valves 46 and 48 or 50 and 52 are closed, and the valve 54 is closed.
Alternatively, 56 is open, and the cold air from the converter 2 and dust chamber 4 is not introduced into the boiler 26 or 28, and the bypass line 42 or 44 is opened.
and is introduced directly into the high-temperature barrel 36 via lines 32 and 34.

In the above description, valves 46, 4 are provided at the inlets and outlets of boilers 26 and 28 to use bypass lines.
Although the mode of arranging 8, 50, and 52 was explained,
Actually, even if such a valve is not provided, the converter exhaust gas automatically flows through the bypass pipes when the bypass pipes 42 and 44 are opened due to the resistance of the boiler itself. Therefore, the valves 46, 48, 50 and 52 are not essential elements in the exhaust heat recovery device of the present invention.

Furthermore, the bypass line 42 or 4 of the device
4 is automatically opened and closed by measuring with a temperature detector 70 that the temperature in the pipe line 30, that is, in the converter exhaust gas, has fallen below a predetermined value, and by opening and closing the control valves 54 and 56. You can also do that.

As understood from the above explanation, in the waste heat recovery apparatus of the present invention, the boilers 26 and 28 are cooled by cold air from the converter and dust chamber generated depending on the operating state of the converter. Therefore, boiler operation can be continued without taking complicated and uneconomical measures such as installing special auxiliary combustion equipment to heat the boiler until hot exhaust gas is fed to the boiler again. Can be maintained in good management condition.

Stopping two converters that are blowing air at the same time should be avoided for the good operation of a sulfuric acid plant, so in the above explanation, if one converter is stopped, 54, boiler 26 by opening one of the bypass flue valves of 56.
Alternatively, although it has been stated that gas should not be introduced into boilers 28, if both converters are forced to stop due to operational reasons, both valves 54 and 56 of the bypass pipes should be opened, and gas should be introduced into boilers 26 and 28. It should be noted that it is possible that all gas introductions may be stopped.

By using the exhaust heat recovery device according to the present invention configured as described above, it is possible to avoid unnecessary installation of a boiler, and the operating rate of the boiler can be significantly increased. Furthermore, there is no need to insulate the boiler tube to prevent corrosion while the converter is not in use, which was required in conventional equipment, and there is an advantage that the boiler can be easily managed. Furthermore, the boiler used in the exhaust heat recovery device of the present invention enables stable generation of steam, making it possible to utilize steam generated by a converter boiler for power generation, which was previously considered impossible.

[Brief explanation of the drawing]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The drawing is a schematic explanatory view showing one embodiment of an apparatus for recovering exhaust heat from a converter for copper smelting according to the present invention. 2: Converter, 4: Dust chamber, 26, 28:
Boiler, 42, 44: Bypass pipeline, 36: High temperature kettle.

Claims (1)

[Scope of Claims] 1. An exhaust heat recovery device for a plurality of copper smelting converters operated at the same time with two furnaces, which connects two or more boilers and the inlets of the boilers in parallel, and an inlet side common pipe having a control valve on each inlet side; and an outlet side common pipe connecting the outlet of the boiler in parallel and having a control valve on each outlet side of the boiler, Connecting the plurality of converters to a portion of the pipe between the control valves at each boiler inlet, Connecting an exhaust gas conduit to a portion of the outlet side common pipe between the control valves at each boiler outlet, A control valve is connected to an intermediate portion of the inlet common pipe between the control valves at each of the boiler inlets, and a portion of the outlet side common pipe between the connection position of the exhaust gas conduit and each of the control valves at the boiler outlet. An exhaust heat recovery device for a copper smelting converter, characterized in that it is connected by a bypass pipe provided with. 2. The device according to claim 1, wherein two boilers are installed. 3. The device according to claim 1, wherein six converters are installed. 4. The device according to claim 1, wherein the control valves of the boiler and the bypass line are opened and closed by a temperature sensor. 5. The device according to claim 1, wherein the exhaust gas conduit is connected to a high temperature cottle.