Low-concentration odor heat exchange device

Abstract

The utility model provides a low-concentration odor heat exchange device, which aims at solving the problem of heat loss caused by the fact that heat energy is not recycled due to the fact that parallel heat exchange is adopted in the prior art, and comprises a gas inlet end, a gas outlet end and a gas outlet end, the gas inlet end is used for the inflow of high-temperature low-concentration odor recovered in the pulping process; the air outlet end is used for enabling the low-temperature and low-concentration odor subjected to heat exchange to flow out; the heat exchange pipe section is arranged between the air inlet end and the air outlet end, the heat exchange pipe section is divided into a plurality of groups of heat exchange areas, each group of heat exchange areas is provided with a soft water inlet and a soft water outlet, the soft water outlet of the previous group of heat exchange areas is connected with the soft water inlet of the next group of heat exchange areas in series, and the soft water outlet of the next group of heat exchange areas is connected with the soft water inlet of the next group of heat exchange areas in series. Soft water is subjected to heat exchange through the previous group and then flows into the next group to be subjected to heat exchange again. According to the tandem heat exchanger, heat recovery is effectively achieved, the temperature of a recovered soft water outlet is higher, and the tandem heat exchanger has higher application value.

Description

Technical Field

[0001] The utility model relates to the technical field of low-concentration odor recovery in a papermaking process, in particular to a low-concentration odor heat exchange device. Background Art

[0002] As we all know, the pulp and paper industry is one of the four major polluting industries in the world, and cooking black liquor and bleaching wastewater are the main pollution sources of the pulp and paper industry. At the same time, the pulp and paper industry is also one of the industries with high material consumption and high energy consumption. With the development of industry, pollution and energy problems are gradually becoming urgent problems that countries around the world need to solve. Therefore, maximizing the treatment of black liquor generated in the pulp and paper production process and recovering heat energy are important and indispensable links in pulp and paper production.

[0003] At present, the pulping production process of a paper mill mainly includes a pulping section and a supporting alkali recovery section. The low-concentration odor gas produced by the pulping of a newly designed paper mill has a high heat content. In order to recycle the low-concentration odor gas again, a common practice is to pass it into an alkali recovery boiler to burn it. The alkali furnace uses the low-concentration odor gas as tertiary air to enter the furnace for combustion. Before entering the furnace for combustion, the low-concentration odor gas needs to be cooled by the circulating water of the evaporative cooling tower through a heat exchanger. The condensed gas is then separated from the gas and water to obtain a relatively dry gas to help combustion. However, in the process of condensation, since no heat energy is recovered, the energy consumption of the cooling tower is increased, which brings economic losses. In addition, the prior art does not have a heat exchange device that can effectively recover the high heat of the low-concentration odor gas generated in the pulping process.

[0004] Therefore, providing a low-concentration odor heat exchange device that can recover heat energy and effectively recycle the energy of low-concentration odor is a technical problem that urgently needs to be solved. Utility Model Content

[0005] The low-concentration odor heat exchange device of the utility model aims to solve the problem that the heat exchanger in the prior art cannot realize the recovery and utilization of the low-concentration odor heat energy after heat exchange because the soft water pipes in each heat exchange temperature zone are connected in parallel.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A low-concentration odor heat exchange device, the low-concentration odor heat exchange device comprising:

[0008] An air inlet end, the air inlet end is used for the inflow of high-temperature low-concentration odor gas recovered in the pulping process;

[0009] An air outlet end, the air outlet end is used for the outflow of low-temperature and low-concentration odor after heat exchange; and

[0010] The heat exchange pipe section is arranged between the air inlet and the air outlet, and the heat exchange pipe section is divided into several groups of heat exchange areas, each group of heat exchange areas is equipped with a soft water inlet and a soft water outlet, wherein the soft water outlet of the previous group of heat exchange areas and the soft water inlet of the next group of heat exchange areas are connected in series, so as to allow the soft water to flow into the next group for further heat exchange after heat exchange in the previous group; wherein,

[0011] The soft water inlet of the first group of heat exchange zones of the heat exchange tube section is connected to the normal temperature soft water pipeline of the deaerator;

[0012] The soft water outlet of the last group of heat exchange zones of the heat exchange tube section is connected to the return water pipeline of the deaerator.

[0013] The low-concentration odor heat exchange device of the utility model changes the parallel heat exchange zone structure into a series type on the basis of the prior art, that is, the water inlet and the water outlet are disconnected, that is, a soft water inlet and a soft water outlet are installed on each group of heat exchange zones, and the soft water outlet of the previous group of heat exchange zones and the soft water inlet of the next group of heat exchange zones are connected in series. The water after heat exchange in each heat exchange zone (the temperature of each group of heat exchange zones is different, this is because the high-temperature low-concentration odor exchanges heat with the inflowing cooling water after passing through the heat exchange plate of the heat exchanger, and the process of conversion from low temperature to medium temperature and then to high temperature is realized after each stage of heat exchange) enters the next temperature zone for heat exchange again until the heat exchange in the last temperature zone. Since the last stage of heat exchange zone is close to the inlet end of the high-temperature low-concentration odor, the outlet water obtained in this way is also the highest temperature. The outlet is connected to a deaerator, and the deaerator requires a high outlet water temperature. Therefore, the heat energy exchange can be maximized, the heat emission can be reduced, and the soft water temperature can be increased, thereby reducing the steam consumption required for boiler feed water preheating.

[0014] As the preferred technical solution:

[0015] In the low-concentration odor heat exchange device as described above, the plurality of heat exchange zones are three groups, namely the first heat exchange zone, the second heat exchange zone and the third heat exchange zone; wherein,

[0016] The first heat exchange zone is close to the gas outlet, and is provided with a first soft water inlet and a first soft water outlet. The first soft water inlet is connected to the normal temperature soft water pipeline of the deaerator, and is used to allow normal temperature soft water to enter the first heat exchange zone through the first soft water inlet for the first heat exchange, and the soft water after the heat exchange flows out from the first soft water outlet;

[0017] The second heat exchange zone is located between the first heat exchange zone and the third heat exchange zone, and is provided with a second soft water inlet and a second soft water outlet. The second soft water inlet and the first soft water outlet are connected in series, and are used for the soft water after the first heat exchange to flow out from the first soft water outlet and then flow into the second soft water inlet and enter the second heat exchange zone for the second heat exchange, and the soft water after the heat exchange flows out from the second soft water outlet;

[0018] The third heat exchange zone is located at the gas outlet end, and is provided with a third soft water inlet and a third soft water outlet. The third soft water inlet and the second soft water outlet are connected in series, and are used for allowing the soft water after the second heat exchange to flow out from the second soft water outlet and then flow into the third soft water inlet and enter the third heat exchange zone for the third heat exchange. The soft water after the heat exchange flows out from the third soft water outlet, and the third soft water outlet is connected to the return water pipe of the deaerator.

[0019] In the low-concentration odor heat exchange device as described above, flanges are installed on both the air inlet end and the air outlet end.

[0020] In the low-concentration odor heat exchange device as described above, a flow control valve is provided on the pipe connecting the soft water inlet of the first group of heat exchange zones with the normal temperature soft water pipe of the deaerator.

[0021] In the low-concentration odor heat exchange device as described above, a flow control valve is provided on the pipe connecting the soft water outlet of the last group of heat exchange zones with the return water pipe of the deaerator.

[0022] Compared with the prior art, the beneficial effects of the utility model are:

[0023] The utility model low-concentration odor heat exchange device connects the cooling water inlet and outlet of each heat exchange zone in series, which reduces the operating load of the evaporative cooling tower, reduces heat emission, and saves electricity consumption compared to the parallel connection method of the prior art. It effectively reuses waste energy, increases the feed water temperature, and reduces the low-pressure steam consumption required for boiler feed water preheating. Due to energy saving, it can indirectly generate economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 It is a structural schematic diagram of a low-concentration odor heat exchange device in the prior art;

[0026] Figure 2 This is a schematic diagram of the structure of the low-concentration odor heat exchange device of the utility model;

[0027] Figure markings: 1-low-concentration odor inlet; 2-low-concentration odor outlet; 3-cooling tower circulating water inlet; 4-cooling tower circulating water outlet; 5-cooling water flow direction; 6-water inlet header; 7-water outlet header; 8-circulating water flow direction; 101-first soft water inlet; 102-first soft water outlet; 201-second soft water inlet; 202-second soft water outlet; 301-third soft water inlet; 302-third soft water outlet; 300-normal temperature soft water inlet; 400-heat exchange soft water outlet. DETAILED DESCRIPTION

[0028] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0029] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the products of the present invention are conventionally placed when in use, or are the orientations or positional relationships conventionally understood by those skilled in the art, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0030] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0031] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0033] The disclosure below provides many different embodiments or examples for realizing different structures of the utility model. In order to simplify the disclosure of the utility model, the components and settings of specific examples are described below. Of course, they are merely examples, and the purpose is not to limit the utility model. In addition, the utility model may repeat reference numbers and / or reference letters in different examples, and such repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the utility model provides various specific examples of processes and materials, but those of ordinary skill in the art may be aware of the application of other processes and / or the use of other materials.

[0034] The embodiments of the present utility model are described in detail below with reference to the accompanying drawings.

[0035] The heat exchanger of the prior art has a structural schematic diagram as shown in Figure 1As shown, the same water inlet header 6 and the same water outlet header 7 are used, which are connected in parallel with the heat exchange zones of each temperature zone. The heat exchange process is as follows: the cooling tower circulating water or normal temperature soft water enters the first heat exchange zone from the cooling tower circulating water inlet 3 through the water inlet header 6 according to the arrow direction of the circulating water flow direction 8, and flows into the water outlet header 7 after heat exchange in the first heat exchange zone according to the arrow direction of the cooling water flow direction 5. The cooling water continues to move forward in the water inlet header 6 and enters the second heat exchange zone. After heat exchange in the second heat exchange zone according to the arrow direction of the cooling water flow direction 5, it flows into the water outlet header 6 again, and then enters the third heat exchange zone, the fourth heat exchange zone..., until the cooling water enters the last stage of the heat exchange zone, exchanges heat, and then flows out from the cooling tower circulating water outlet 4 according to the arrow direction of the circulating water flow direction 8, and the low concentration After the high-temperature airflow at the odor inlet 1 flows into the heat exchange of different temperature zones, a low-temperature airflow is obtained at the low-concentration odor outlet 2. After flowing out, it passes through the gas-liquid separator to obtain dry low-temperature gas. Although the whole process realizes the heat exchange of high-temperature low-concentration odor to low-temperature low-concentration odor, the problems of this heat exchanger are: 1. During the whole heat exchange process, since the cooling water continuously enters the water inlet header, the cooling tower will continue to work, the energy consumption is very high, and a large amount of economic losses will be caused; 2. In the process of heat exchange, the heat energy is not effectively recovered, and a large amount of heat energy is lost in the process of heat exchange; 3. The water after heat exchange in the low-temperature zone and the water after heat exchange in the high-temperature zone are mixed at a lower temperature, and it is almost difficult to obtain a high outlet water temperature.

[0036] The present invention provides a low-concentration odor heat exchange device, comprising:

[0037] The air inlet end is used for the inflow of high-temperature low-concentration odor recovered in the pulping process. The air inlet end is equipped with a flange for connecting with the ventilation pipe for the inflow of low-concentration odor before heat exchange;

[0038] An air outlet end, the air outlet end is used for the outflow of low-temperature and low-concentration odor after heat exchange, and the air outlet end is installed with a flange for connecting with a return air duct for the outflow of low-concentration odor after heat exchange; and,

[0039] The heat exchange pipe section is arranged between the air inlet and the air outlet. The heat exchange pipe section is divided into several groups of heat exchange areas. Each group of heat exchange areas is equipped with a soft water inlet and a soft water outlet. The soft water outlet of the previous group of heat exchange areas and the soft water inlet of the next group of heat exchange areas are connected in series to allow the soft water to flow into the next group for further heat exchange after the previous group of heat exchange.

[0040] The soft water inlet of the first group of heat exchange zones of the heat exchange tube section is connected to the normal temperature soft water pipeline of the deaerator;

[0041] The soft water outlet of the last group of heat exchange zones of the heat exchange tube section is connected to the return water pipeline of the deaerator.

[0042] A flow control valve is arranged on the pipeline connecting the soft water inlet of the first group of heat exchange zones with the normal temperature soft water pipeline of the deaerator.

[0043] A flow control valve is provided on the pipeline connecting the soft water outlet of the last group of heat exchange zones and the return water pipeline of the deaerator.

[0044] As a more preferred embodiment, the utility model embodiment provides a low-concentration odor heat exchange device with three groups of heat exchange zones, namely a first heat exchange zone, a second heat exchange zone and a third heat exchange zone, such as Figure 2 As shown:

[0045] The first heat exchange zone is close to the gas outlet, that is, close to the low-concentration odor outlet 2. The first heat exchange zone is provided with a first soft water inlet 101 and a first soft water outlet 102, wherein the first soft water inlet 101 is connected to the normal temperature soft water pipeline of the deaerator, and is used for normal temperature soft water to enter the normal temperature soft water inlet 300, and then enter the first heat exchange zone through the first soft water inlet 101 for the first heat exchange. The normal temperature soft water flows into the first heat exchange zone and flows in the direction of the arrow of the cooling water flow direction 5. The soft water after heat exchange flows out from the first soft water outlet 102;

[0046] The second heat exchange zone is located between the first heat exchange zone and the third heat exchange zone, and is provided with a second soft water inlet 201 and a second soft water outlet 202. The second soft water inlet 201 and the first soft water outlet 102 are connected in series, and are used for the soft water after the first heat exchange to flow out from the first soft water outlet 102 in the direction of the arrow of the circulating water flow direction 8, and then flow into the second soft water inlet 201 to enter the second heat exchange zone for the second heat exchange. During the heat exchange, the soft water flows in the direction of the arrow of the cooling water flow direction 5, and the soft water after the heat exchange flows out from the second soft water outlet 202;

[0047] The third heat exchange zone is located at the gas outlet end, that is, close to the low-concentration odor inlet 1, and is provided with a third soft water inlet 301 and a third soft water outlet 302. The third soft water inlet 301 and the second soft water outlet 302 are connected in series, and are used for the soft water after the second heat exchange to flow out from the second soft water outlet 202 in the direction of the arrow of the circulating water flow direction 8, and flow into the third soft water inlet 301 to enter the third heat exchange zone for the third heat exchange. During heat exchange, it flows in the direction of the arrow of the cooling water flow direction 5, and the soft water after heat exchange flows out from the third soft water outlet 302. The third soft water outlet 302 is connected to the return water pipe of the deaerator, and finally the soft water after heat exchange flows out from the heat exchange soft water outlet 400 and flows back to the deaerator for boiler feed water.

[0048] The utility model discloses a low-concentration odor heat exchange device, which divides the atmosphere of the heat exchange pipe section into several heat exchange zones. Different heat exchange zones form different heat exchange temperature zones due to continuous heat exchange with the low-concentration odor. The high-temperature low-concentration odor is successively heat exchanged with the high-temperature (third heat exchange zone), the medium-temperature (second heat exchange zone) and the low-temperature (first heat exchange zone) to obtain low-temperature low-concentration odor. At the same time, soft water at room temperature is used as circulating water. After entering the heat exchange plate in the heat exchanger, it is also circulated from the low-temperature (first heat exchange zone), the medium-temperature (second heat exchange zone) to the high-temperature (third heat exchange zone) heat exchange zone, and high-temperature circulating water is obtained at the outlet. On the one hand, this series connection realizes gradual heat exchange and effectively reduces the impact on the life of the equipment due to excessive temperature difference. On the other hand, heat energy is effectively recovered in the whole process, which greatly saves the power consumption of the equipment, effectively reuses the waste energy, improves the feed water temperature, reduces the low-pressure steam consumption required for boiler feed water preheating, indirectly generates economic benefits, and has a good application prospect.

Claims

1. A low-concentration odor heat exchange device, characterized in that: The low-concentration odor heat exchange device comprises: An air inlet end, the air inlet end is used for the inflow of high-temperature low-concentration odor gas recovered in the pulping process; An air outlet end, the air outlet end is used for the outflow of low-temperature and low-concentration odor after heat exchange; and The heat exchange pipe section is arranged between the air inlet and the air outlet, and the heat exchange pipe section is divided into several groups of heat exchange areas, each group of heat exchange areas is equipped with a soft water inlet and a soft water outlet, wherein the soft water outlet of the previous group of heat exchange areas and the soft water inlet of the next group of heat exchange areas are connected in series, so as to allow the soft water to flow into the next group for further heat exchange after heat exchange in the previous group; wherein, The soft water inlet of the first group of heat exchange zones of the heat exchange tube section is connected to the normal temperature soft water pipeline of the deaerator; The soft water outlet of the last group of heat exchange zones of the heat exchange tube section is connected to the return water pipeline of the deaerator.

2. A low-concentration odor heat exchange device according to claim 1, characterized in that: The plurality of groups of heat exchange zones are three groups, namely the first heat exchange zone, the second heat exchange zone and the third heat exchange zone; wherein, The first heat exchange zone is close to the gas outlet, and is provided with a first soft water inlet and a first soft water outlet. The first soft water inlet is connected to the normal temperature soft water pipeline of the deaerator, and is used to allow normal temperature soft water to enter the first heat exchange zone through the first soft water inlet for the first heat exchange, and the soft water after the heat exchange flows out from the first soft water outlet; The second heat exchange zone is located between the first heat exchange zone and the third heat exchange zone, and is provided with a second soft water inlet and a second soft water outlet. The second soft water inlet and the first soft water outlet are connected in series, and are used for the soft water after the first heat exchange to flow out from the first soft water outlet and then flow into the second soft water inlet and enter the second heat exchange zone for the second heat exchange, and the soft water after the heat exchange flows out from the second soft water outlet; The third heat exchange zone is located at the gas outlet end, and is provided with a third soft water inlet and a third soft water outlet. The third soft water inlet and the second soft water outlet are connected in series, and are used for allowing the soft water after the second heat exchange to flow out from the second soft water outlet and then flow into the third soft water inlet and enter the third heat exchange zone for the third heat exchange. The soft water after the heat exchange flows out from the third soft water outlet, and the third soft water outlet is connected to the return water pipe of the deaerator.

3. A low-concentration odor heat exchange device according to claim 1, characterized in that: The air inlet end and the air outlet end are both equipped with flanges.

4. The low-concentration odor heat exchange device according to claim 1, characterized in that: A flow control valve is provided on the pipeline connecting the soft water inlet of the first group of heat exchange zones and the normal temperature soft water pipeline of the deaerator.

5. The low-concentration odor heat exchange device according to claim 1, characterized in that: A flow control valve is provided on the pipe connecting the soft water outlet of the last group of heat exchange zones with the return water pipe of the deaerator.

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