A hot blast stove flue gas waste heat recovery system

Abstract

The application provides a hot blast furnace flue gas waste heat recovery system, and relates to the technical field of flue gas waste heat recovery.The system comprises a hot blast furnace with a flue gas outlet, a washing and drying oven with a washing chamber and a drying chamber which are independent of each other, a water inlet at the upper part of the washing chamber, a water outlet at the lower part of the washing chamber, a flue gas outlet at the upper part of the drying chamber, a flue gas inlet at the lower part of the drying chamber, a dust removal device connected between the flue gas outlet and the flue gas inlet, a heat exchanger with a first channel, a second channel and a third channel, the flue gas outlet, the first channel and the water inlet being connected in sequence, the flue gas outlet being connected with the second channel, and the water outlet, the third channel and the water inlet being connected in sequence.The application avoids the particles in the flue gas from adhering to the surface of the workpiece in the drying chamber, and increases the temperature of the washing water, which is beneficial to washing the oil stains on the surface of the workpiece and increasing the temperature of the surface of the workpiece, thereby reducing the difficulty of subsequent drying.

Description

Technical Field

[0001] This utility model relates to the field of flue gas waste heat recovery technology, and in particular to a hot blast stove flue gas waste heat recovery system. Background Technology

[0002] Hot blast furnaces are widely used in various fields. When hot blast furnaces are working, they generate a large amount of high-temperature dusty flue gas, and the waste heat of this flue gas can be recovered and utilized.

[0003] The patent document discloses a waste heat recovery and utilization device for hot air furnace flue gas (application number CN202420332996.5), which uses the waste heat of hot air furnace flue gas to directly dry agricultural products in the drying oven, and uses the heat recovered by the heat exchanger to heat cold air to indirectly dry agricultural products; the flue gas will return to the drying oven after leaving the drying oven, thus making full use of the waste heat of the flue gas to dry agricultural products.

[0004] However, if the above solution is directly applied to the steel industry to use the waste heat of hot blast stove flue gas to dry cleaned workpieces, the following drawbacks will exist:

[0005] 1. When a portion of the dust-laden flue gas comes into direct contact with a damp workpiece, the particulate matter in the flue gas easily combines with water and adheres to the surface of the workpiece, resulting in incomplete cleaning.

[0006] 2. The heat recovery rate of ordinary heat exchangers is generally not very high (non-contact heat exchange), which brings the following problems: On the one hand, the flue gas still has a relatively high temperature after passing through the heat exchanger, and the waste heat of this part of the flue gas can be further recovered and utilized; on the other hand, the temperature of the hot air obtained after the cold air is heated is not very high, while the flue gas that directly enters the oven has a relatively high residual temperature after leaving the oven (the flue gas stays in the oven for a limited time). If the relatively low-temperature hot air and the flue gas with a relatively high residual temperature leaving the oven are combined, the two will exchange heat, which will reduce the temperature of the gas returning to the oven, affecting the waste heat recovery rate of the flue gas, and there is still room for further improvement. Utility Model Content

[0007] In view of the above situation, the present invention provides a hot blast stove flue gas waste heat recovery system, which aims to solve the defects pointed out in the background art.

[0008] To achieve the above objectives, this utility model provides the following technical solution:

[0009] This utility model provides a waste heat recovery system for hot blast stove flue gas, including:

[0010] Hot air furnace, equipped with a flue gas vent;

[0011] The washing and drying oven has independent washing and drying chambers; the washing chamber has a water inlet at the top and a drain at the bottom; the drying chamber has a flue gas outlet at the top and a flue gas inlet at the bottom.

[0012] Dust removal equipment is connected between the exhaust port and the flue gas inlet;

[0013] The heat exchanger has a first channel, a second channel, and a third channel; the flue gas outlet, the first channel, and the water inlet are connected in sequence; the flue gas outlet is connected to the second channel; and the drain outlet, the third channel, and the water inlet are connected in sequence.

[0014] In some embodiments of this utility model, the dust removal equipment includes a cyclone dust collector.

[0015] In some embodiments of this utility model, a storage tank for storing cleaning fluid is also included, with the outlet of the storage tank connected to the inlet.

[0016] In some embodiments of this utility model, a flow meter is provided between the third channel and the inlet; a flow regulating valve is provided at the outlet of the storage tank, and the flow regulating valve is associated with the flow meter.

[0017] In some embodiments of this utility model, a purification water tank is also included, and the exhaust port, the second channel and the purification water tank are connected in sequence.

[0018] In some embodiments of this utility model, a filter is also included. The filter is connected between the drain outlet and the third channel. The filter is connected to the third channel through a clean water pipe, and a first valve is provided on the clean water pipe.

[0019] In some embodiments of this invention, a water replenishment tank connected to the third channel is also included.

[0020] In some embodiments of this utility model, the water supply tank is connected to the clean water pipe via a water supply pipe, and a second valve is provided on the water supply pipe, with the first valve and the second valve connected in parallel.

[0021] The embodiments of this utility model have at least the following advantages or beneficial effects:

[0022] By setting up a hot air furnace, washing and drying oven, dust removal equipment, and heat exchanger, particulate matter in the flue gas is prevented from entering the drying chamber and adhering to the surface of the workpiece. The flue gas directly from the hot air furnace and the waste heat from the flue gas discharged from the drying chamber are used to heat the cleaning water, raising the temperature of the cleaning water. This is more conducive to washing away impurities such as oil and metal shavings from the surface of the workpiece, and it can also increase the surface temperature of the workpiece, reducing the difficulty of subsequent drying.

[0023] Other features and advantages of this invention will be set forth in the following description. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the waste heat recovery system for hot blast stove flue gas.

[0026] icon:

[0027] 1-Hot air furnace, 11-Smoke exhaust port

[0028] 2-Washing and drying oven, 21-Washing chamber, 211-Water inlet, 212-Drain outlet, 213-Spray head, 22-Drying chamber, 221-Flue gas outlet, 222-Flue gas inlet.

[0029] 3-Cyclone dust collector,

[0030] 4-Heat exchanger, 41-First channel, 42-Second channel, 43-Third channel

[0031] 5-Liquid storage tank,

[0032] 6-Filter, 61-Clean water pipe, 62-First valve

[0033] 7-Water supply tank, 71-Water supply pipe, 72-Second valve

[0034] 8-Purification water tank. Detailed Implementation

[0035] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the present invention.

[0036] In the description of the embodiments of this utility model, it should be understood that the terms "upper", "lower", "inner", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the embodiments of this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this utility model.

[0037] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0038] In this embodiment of the invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this embodiment of the invention according to the specific circumstances.

[0039] The embodiments of this utility model will be described in detail below.

[0040] Example

[0041] See Figure 1 This embodiment provides a waste heat recovery system for flue gas from a hot air furnace 1, including a hot air furnace 1, a washing and drying oven 2, a dust removal device, a heat exchanger 4, a liquid storage tank 5, a filter 6, and a water replenishment tank 7.

[0042] The hot air furnace 1 has a flue gas outlet 11.

[0043] The washer-dryer 2 has an independent washing chamber 21 and a drying chamber 22. The washing chamber 21 has a water inlet 211 at the top and a drain outlet 212 at the bottom. The water inlet 211 is connected to a spray head 213, and multiple spray heads 213 are evenly distributed inside the upper part of the washing chamber 21. The drying chamber 22 has a flue gas outlet 221 at the top and a flue gas inlet 222 at the bottom.

[0044] The dust removal equipment is connected between the exhaust port 11 and the flue gas inlet 222. The dust removal equipment includes a cyclone dust collector 3.

[0045] The heat exchanger 4 has a first channel 41, a second channel 42, and a third channel 43. The flue gas outlet 221, the first channel 41, and the water inlet 211 are connected in sequence. The exhaust outlet 11, the second channel 42, and the purified water tank 8 are connected in sequence. The drain outlet 212, the third channel 43, and the water inlet 211 are connected in sequence. A flow meter (not shown in the figure) is installed between the third channel 43 and the water inlet 211.

[0046] The storage tank 5 is used to store cleaning fluid. The outlet of the storage tank 5 is connected to the inlet 211. A flow regulating valve (not shown in the figure) is installed at the outlet of the storage tank 5. The flow regulating valve is associated with the flow meter.

[0047] Filter 6 is connected between drain outlet 212 and third channel 43. Filter 6 is connected to third channel 43 via clean water pipe 61, and a first valve 62 is installed on clean water pipe 61. Filter 6 contains a filter screen.

[0048] The water supply tank 7 is connected to the clean water pipe 61 via the water supply pipe 71. The water supply pipe 71 is equipped with a second valve 72, and the first valve 62 and the second valve 72 are connected in parallel.

[0049] The working principle of the waste heat recovery system of hot blast stove 1 is as follows:

[0050] Cleaning water is sprayed from spray head 213 onto the surface of the workpiece to be cleaned in cleaning chamber 21 to rinse away oil stains, etc., and then returns to cleaning chamber 21 through filter 6 and third channel 43 to achieve circulation; the flow regulating valve is associated with the flow meter to adjust the amount of cleaning liquid according to the flow rate of the cleaning water. After being cleaned, the workpiece is transferred from cleaning chamber 21 to drying chamber 22. After the high-temperature flue gas from hot air furnace 1 is discharged from exhaust port 11, part of the high-temperature flue gas enters the purification water tank 8 through second channel 42 to cool and remove particulate matter before being discharged; the other part of the high-temperature flue gas enters the drying chamber 22 after the dust removal equipment removes particulate matter, and dries the surface of the cleaned workpiece. The flue gas in drying chamber 22 is discharged from flue gas outlet 221 into first channel 41 and is heated by the high-temperature flue gas in second channel 42, and then merges with the cleaning water near water inlet 211 (which has been heated by the high-temperature flue gas in second channel 42) for heat exchange, further increasing the temperature of the cleaning water, which is more conducive to washing away oil stains, etc.

[0051] This embodiment is based on existing technology and has been modified accordingly; compared with existing technology, this embodiment has at least the following beneficial effects:

[0052] 1. By setting up the hot air furnace 1, the washing and drying oven 2, the dust removal equipment and the heat exchanger 4, it is possible to prevent particulate matter in the flue gas from entering the drying chamber 22 and adhering to the surface of the workpiece. At the same time, the flue gas directly from the hot air furnace 1 and the waste heat of the flue gas discharged from the drying chamber 22 are used to heat the cleaning water, thereby raising the temperature of the cleaning water. This is more conducive to washing away impurities such as oil stains and metal shavings from the surface of the workpiece. On the other hand, it can increase the temperature of the workpiece surface and reduce the difficulty of subsequent drying (or improve the subsequent drying efficiency).

[0053] 2. By linking the flow regulating valve to the flow meter, the amount of cleaning fluid can be adjusted according to the flow rate of the cleaning water, thus avoiding waste of cleaning fluid.

[0054] 3. The use of filter 6 reduces the consumption of cleaning water. Furthermore, when the filter screen of filter 6 becomes clogged, the second valve 72 can be opened and the first valve 62 closed to backwash the filter screen, thereby extending the replacement cycle of the filter screen in filter 6. When both the second valve 72 and the first valve 62 are open, cleaning water can be added.

[0055] Finally, it should be noted that the above are merely preferred embodiments of this application and are not intended to limit this application. For those skilled in the art, this application can have various modifications and variations. Without conflict, the embodiments and features described in the embodiments of this application can be arbitrarily combined with each other. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A waste heat recovery system for hot blast stove flue gas, characterized in that, include: Hot air furnace, equipped with a flue gas vent; The washer-dryer has separate washing and drying chambers. The cleaning chamber has a water inlet at the top and a drain outlet at the bottom; the drying chamber has a flue gas outlet at the top and a flue gas inlet at the bottom. Dust removal equipment is connected between the exhaust port and the flue gas inlet; A heat exchanger having a first channel, a second channel, and a third channel; the flue gas outlet, the first channel, and the water inlet are connected in sequence; the flue gas outlet and the second channel are connected; and the drain outlet, the third channel, and the water inlet are connected in sequence.

2. The waste heat recovery system for hot blast stove flue gas according to claim 1, characterized in that, The dust removal equipment includes a cyclone dust collector.

3. The hot blast stove flue gas waste heat recovery system according to claim 1, characterized in that, It also includes a storage tank for storing cleaning fluid, the outlet of which is connected to the inlet.

4. The hot blast stove flue gas waste heat recovery system according to claim 3, characterized in that, A flow meter is installed between the third channel and the inlet; a flow regulating valve is installed at the outlet of the liquid storage tank, and the flow regulating valve is associated with the flow meter.

5. The hot blast stove flue gas waste heat recovery system according to claim 1, characterized in that, It also includes a purification water tank, and the exhaust port, the second channel and the purification water tank are connected in sequence.

6. The hot blast stove flue gas waste heat recovery system according to any one of claims 1 to 5, characterized in that, It also includes a filter connected between the drain outlet and the third channel. The filter is connected to the third channel via a water purification pipe, and a first valve is provided on the water purification pipe.

7. The hot blast stove flue gas waste heat recovery system according to claim 6, characterized in that, It also includes a water replenishment tank connected to the third channel.

8. The hot blast stove flue gas waste heat recovery system according to claim 7, characterized in that, The water supply tank is connected to the clean water pipe via a water supply pipe. A second valve is installed on the water supply pipe, and the first valve and the second valve are connected in parallel.

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