Energy-saving device for natural gas solid alkali heating furnace in chlor-alkali production

Abstract

This utility model relates to the field of chlor-alkali production technology and is an energy-saving device for a natural gas solid alkali heating furnace used in chlor-alkali production. It includes a solid alkali heating furnace, a combustion air heater, a natural gas heater, and a combustion air blower. A first natural gas pipeline is fixedly connected to the lower inlet of the natural gas heater. A second natural gas pipeline is fixedly connected between the lower outlet of the natural gas heater and the top inlet of the solid alkali heating furnace. A first flue gas pipeline is fixedly connected between the lower flue gas outlet of the solid alkali heating furnace and the natural gas heater. A second flue gas pipeline is fixedly connected between the natural gas heater and the combustion air heater. The first combustion air pipeline is fixedly connected between the outlet of the combustion air blower and the combustion air heater. This utility model utilizes the heat from the flue gas in the solid alkali heating furnace to heat the natural gas and combustion air, increasing the temperature of the natural gas before combustion, reducing heat loss, and thus reducing energy consumption. It features safety, energy saving, and environmental protection.

Description

Technical Field

[0001] This utility model relates to the field of chlor-alkali production technology and is an energy-saving device for a natural gas solid alkali heating furnace used in chlor-alkali production. Background Technology

[0002] Currently, some solid alkali units in chlor-alkali chemical production facilities utilize natural gas-fired solid alkali heaters. These heaters concentrate the liquid alkali obtained from the electrolysis process through evaporation to produce high-concentration solid alkali products. The natural gas-fired solid alkali heaters use natural gas as fuel, which is thoroughly mixed with combustion air and combusted via a burner to generate a high-temperature flame and heat. This heat is transferred through furnace tubes and other components to molten salt circulating within the tubes. The molten salt, acting as a heat carrier, is heated to the required temperature and then transported to the final concentrator. There, it undergoes counter-current heat exchange with approximately 62% alkali solution, concentrating the solution to a high concentration of over 98.2%, thus completing the solid alkali evaporation and concentration process.

[0003] Compared to coal or heavy oil heating, natural gas-fired solid alkali heaters produce fewer combustion pollutants and are more likely to meet environmental protection requirements. However, existing natural gas-fired solid alkali heaters still suffer from insufficient thermal efficiency design, such as inadequate recovery of flue gas waste heat. Additionally, the relatively low temperature of the natural gas and combustion air entering the heater also leads to additional heat consumption. Summary of the Invention

[0004] This utility model provides an energy-saving device for a natural gas solid alkali heating furnace used in chlor-alkali production, which overcomes the shortcomings of the prior art and can effectively solve the problems of low thermal efficiency and high natural gas consumption of existing solid alkali heating furnaces.

[0005] The technical solution of this utility model is achieved through the following measures: An energy-saving device for a natural gas solid alkali heating furnace for chlor-alkali production, comprising a solid alkali heating furnace, a combustion air heater, a natural gas heater, and a combustion air blower. A first natural gas pipeline is fixedly connected to the lower air inlet of the natural gas heater. A second natural gas pipeline is fixedly connected between the lower air outlet of the natural gas heater and the top natural gas inlet of the solid alkali heating furnace. An ignition inlet pipeline is fixedly connected between the first natural gas pipeline and the top ignition inlet of the solid alkali heating furnace. A first flue gas pipeline is fixedly connected between the lower flue gas outlet of the solid alkali heating furnace and the right air inlet of the natural gas heater. A second flue gas pipeline is fixedly connected between the left air outlet of the natural gas heater and the lower air inlet of the combustion air heater. A flue gas emission pipeline is fixedly connected to the upper air outlet of the combustion air heater. A first combustion air pipeline is fixedly connected between the air outlet of the combustion air blower and the right air inlet of the combustion air heater. A second combustion air pipeline is fixedly connected between the left air outlet of the combustion air heater and the upper combustion air inlet of the solid alkali heating furnace.

[0006] The following are further optimizations and / or improvements to the above-mentioned utility model technical solution:

[0007] The lower feed end of the aforementioned solid alkali heating furnace is fixedly connected to a molten salt feed pipeline, and the upper discharge end of the solid alkali heating furnace is fixedly connected to a molten salt discharge pipeline.

[0008] A third combustion air pipeline is fixedly connected between the first and second combustion air pipelines.

[0009] A first combustion air valve is fixedly installed on the first combustion air pipeline between the aforementioned combustion air blower and the third combustion air pipeline. A second combustion air valve is fixedly installed on the first combustion air pipeline between the third combustion air pipeline and the combustion air heater. A third combustion air valve is fixedly installed on the third combustion air pipeline.

[0010] A first connecting pipeline is fixedly connected between the first natural gas pipeline and the second natural gas pipeline between the aforementioned ignition intake pipeline and the natural gas heater.

[0011] The aforementioned ignition inlet pipeline and the second natural gas pipeline between the first connecting pipeline and the solid alkali heating furnace are fixedly connected by a second connecting pipeline.

[0012] A first natural gas valve is fixedly installed on the first natural gas pipeline between the ignition inlet pipeline and the first connecting pipeline; a second natural gas valve is fixedly installed on the first natural gas pipeline between the first connecting pipeline and the natural gas heater; a third natural gas valve is fixedly installed on the second natural gas pipeline between the first connecting pipeline and the natural gas heater; a fourth natural gas valve is fixedly installed on the first connecting pipeline; a fifth natural gas valve is fixedly installed on the second connecting pipeline; a sixth natural gas valve is fixedly installed on the second natural gas pipeline between the second connecting pipeline and the solid alkali heater; and a seventh natural gas valve is fixedly installed on the ignition inlet pipeline between the second connecting pipeline and the solid alkali heater.

[0013] This utility model has a reasonable and compact structure and is easy to use. It utilizes the heat from the flue gas of the solid alkali heating furnace to heat the natural gas and combustion air, thereby increasing the temperature of the natural gas before combustion, reducing heat loss, and thus reducing energy consumption. It is safe, energy-saving, and environmentally friendly. Attached Figure Description

[0014] Appendix Figure 1 This is a schematic diagram of the process flow of this utility model.

[0015] The codes in the attached diagram are as follows: 1 is the solid alkali heating furnace, 2 is the combustion air heater, 3 is the natural gas heater, 4 is the combustion air fan, 5 is the first natural gas pipeline, 6 is the second natural gas pipeline, 7 is the ignition inlet pipeline, 8 is the first flue gas pipeline, 9 is the second flue gas pipeline, 10 is the flue gas discharge pipeline, 11 is the first combustion air pipeline, 12 is the second combustion air pipeline, 13 is the molten salt feed pipeline, 14 is the molten salt discharge pipeline, 15 is the third combustion air pipeline, 16 is the first connecting pipeline, 17 is the second connecting pipeline, 18 is the first combustion air valve, 19 is the second combustion air valve, 20 is the third combustion air valve, 21 is the first natural gas valve, 22 is the second natural gas valve, 23 is the third natural gas valve, 24 is the fourth natural gas valve, 25 is the fifth natural gas valve, 26 is the sixth natural gas valve, and 27 is the seventh natural gas valve. Detailed Implementation

[0016] This utility model is not limited to the following embodiments, and the specific implementation method can be determined according to the technical solution of this utility model and the actual situation. In this utility model, unless otherwise specified, the equipment and devices used are all existing and publicly known equipment and devices in the art. In this utility model, for ease of description, the description of the relative positional relationships of each component is based on the appendix to the specification. Figure 1 The layout is described using a diagrammatic method, such as the positional relationships of front, back, top, bottom, left, and right, which are based on the instructions attached. Figure 1 The orientation of the layout is determined by the direction of the map.

[0017] The present invention will be further described below with reference to the embodiments and accompanying drawings:

[0018] Example 1: As shown in the attached document Figure 1 As shown, the energy-saving device for the natural gas solid alkali heating furnace used in chlor-alkali production includes a solid alkali heating furnace 1, a combustion air heater 2, a natural gas heater 3, and a combustion air blower 4. A first natural gas pipeline 5 is fixedly connected to the lower inlet end of the natural gas heater 3. A second natural gas pipeline 6 is fixedly connected between the lower outlet end of the natural gas heater 3 and the top natural gas inlet end of the solid alkali heating furnace 1. An ignition inlet pipeline 7 is fixedly connected between the first natural gas pipeline 5 and the top ignition inlet end of the solid alkali heating furnace 1. The lower flue gas outlet end of the solid alkali heating furnace 1 is connected to... A first flue gas pipeline 8 is fixedly connected to the right air inlet of the natural gas heater 3. A second flue gas pipeline 9 is fixedly connected to the left air outlet of the natural gas heater 3 and the lower air inlet of the combustion air heater 2. A flue gas discharge pipeline 10 is fixedly connected to the upper air outlet of the combustion air heater 2. A first combustion air pipeline 11 is fixedly connected to the right air inlet of the combustion air heater 2. A second combustion air pipeline 12 is fixedly connected to the left air outlet of the combustion air heater 2 and the upper combustion air inlet of the solid alkali heating furnace 1.

[0019] The energy-saving device for the natural gas solid alkali heating furnace used in chlor-alkali production can be further optimized and / or improved according to actual needs:

[0020] Example 2: Its difference from Example 1 is as follows: (See attached) Figure 1 As shown, the lower feed end of the solid alkali heating furnace 1 is fixedly connected to the molten salt feed pipeline 13, and the upper discharge end of the solid alkali heating furnace 1 is fixedly connected to the molten salt discharge pipeline 14.

[0021] Example 3: Its difference from Examples 1 to 2 is as follows: (See attached) Figure 1 As shown, a third combustion air pipeline 15 is fixedly connected between the first combustion air pipeline 11 and the second combustion air pipeline 12.

[0022] Example 4: Its difference from Examples 1 to 3 is as follows: (See attached) Figure 1 As shown, a first combustion air valve 18 is fixedly installed on the first combustion air pipeline 11 between the combustion air blower 4 and the third combustion air pipeline 15. A second combustion air valve 19 is fixedly installed on the first combustion air pipeline 11 between the third combustion air pipeline 15 and the combustion air heater 2. A third combustion air valve 20 is fixedly installed on the third combustion air pipeline 15.

[0023] Example 5: It differs from Examples 1 to 4 in that, as shown in the appendix... Figure 1 As shown, a first connecting pipeline 16 is fixedly connected between the first natural gas pipeline 5 and the second natural gas pipeline 6 between the ignition intake pipeline 7 and the natural gas heater 3.

[0024] Example 6: Its difference from Examples 1 to 5 is as follows: (See attached) Figure 1 As shown, a second connecting pipeline 17 is fixedly connected between the ignition inlet pipeline 7, the first connecting pipeline 16, and the second natural gas pipeline 6 between the solid alkali heating furnace 1.

[0025] Example 7: Its difference from Examples 1 to 6 is as follows: (See attached) Figure 1 As shown, a first natural gas valve 21 is fixedly installed on the first natural gas pipeline 5 between the ignition inlet pipeline 7 and the first connecting pipeline 16; a second natural gas valve 22 is fixedly installed on the first natural gas pipeline 5 between the first connecting pipeline 16 and the natural gas heater 3; a third natural gas valve 23 is fixedly installed on the second natural gas pipeline 6 between the first connecting pipeline 16 and the natural gas heater 3; a fourth natural gas valve 24 is fixedly installed on the first connecting pipeline 16; a fifth natural gas valve 25 is fixedly installed on the second connecting pipeline 17; a sixth natural gas valve 26 is fixedly installed on the second natural gas pipeline 6 between the second connecting pipeline 17 and the solid alkali heater 1; and a seventh natural gas valve 27 is fixedly installed on the ignition inlet pipeline 7 between the second connecting pipeline 17 and the solid alkali heater 1.

[0026] As required, valves and instruments to ensure the normal operation of the energy-saving device for the natural gas solid alkali heating furnace used in chlor-alkali production are fixedly installed on each pipeline.

[0027] When starting up the natural gas-fired solid alkali heater 1, the combustion air blower 4 is activated to ventilate the heater 1. After the ventilation is deemed adequate, the seventh natural gas valve 27 is opened, and ignition gas is introduced into the heater 1 for ignition. After successful ignition, the third natural gas valve 23, the second natural gas valve 22, and the first natural gas valve 21 are opened sequentially, the fourth natural gas valve 24 and the fifth natural gas valve 25 are closed, and the sixth natural gas valve 26 is opened to supply gas for combustion in the solid alkali heater 1. Simultaneously, the high-temperature flue gas generated by the combustion in the solid alkali heater 1 is used to heat the natural gas and the combustion air. The natural gas used in the solid alkali heater 1 is heated from 25°C to 125°C by the natural gas heater 3. According to the heat transfer theory (Q=C*M*△t), the natural gas consumption at full load production is 1000 m³ / hour. 3 Calculation (C=2156J / (kg·k); ρ=0.75kg / m) 3 Up to 0.8kg / m 3 It can save 161,700 KJ to 172,480 KJ per hour, and with 8,000 hours of operation per year, each natural gas solid alkali heating furnace can save approximately 47.1 tons of standard coal per year.

[0028] In summary, this utility model provides an energy-saving device for a natural gas solid alkali heating furnace used in chlor-alkali production. It utilizes the high-temperature flue gas generated by the solid alkali heating furnace to preheat the natural gas and combustion air, raising the temperature of the natural gas used as fuel from 25°C to 125°C. By preheating, the temperature of the natural gas and combustion air before combustion is increased, reducing heat loss and thus reducing energy consumption. It features safety, energy saving, and environmental protection.

[0029] The above technical features constitute various embodiments of this utility model, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

Claims

1. An energy saving device for a natural gas solid caustic soda heating furnace for chlor-alkali production, characterized in that The system includes a solid alkali heater, a combustion air heater, a natural gas heater, and a combustion air blower. A first natural gas pipeline is fixedly connected to the lower inlet of the natural gas heater. A second natural gas pipeline is fixedly connected between the lower outlet of the natural gas heater and the top natural gas inlet of the solid alkali heater. An ignition inlet pipeline is fixedly connected between the first natural gas pipeline and the top ignition inlet of the solid alkali heater. A first flue gas pipeline is fixedly connected between the lower flue gas outlet of the solid alkali heater and the right inlet of the natural gas heater. A second flue gas pipeline is fixedly connected between the left outlet of the natural gas heater and the lower inlet of the combustion air heater. A flue gas discharge pipeline is fixedly connected to the upper outlet of the combustion air heater. A first combustion air pipeline is fixedly connected between the outlet of the combustion air blower and the right inlet of the combustion air heater. A second combustion air pipeline is fixedly connected between the left outlet of the combustion air heater and the upper combustion air inlet of the solid alkali heater.

2. The energy saving device for natural gas solid caustic soda heating furnace for chlor-alkali production according to claim 1, characterized in that The lower feed end of the solid alkali heating furnace is fixedly connected to a molten salt feed pipeline, and the upper discharge end of the solid alkali heating furnace is fixedly connected to a molten salt discharge pipeline.

3. The energy saving device for natural gas solid caustic soda heating furnace for chlor-alkali production according to claim 1 or 2, characterized in that A third combustion air pipeline is fixedly connected between the first and second combustion air pipelines.

4. The energy-saving device for a natural gas solid alkali heating furnace for chlor-alkali production according to claim 3, characterized in that... A first combustion air valve is fixedly installed on the first combustion air pipeline between the combustion air blower and the third combustion air pipeline. A second combustion air valve is fixedly installed on the first combustion air pipeline between the third combustion air pipeline and the combustion air heater. A third combustion air valve is fixedly installed on the third combustion air pipeline.

5. The energy saving device for natural gas solid caustic soda heating furnace for chlor-alkali production according to claim 1 or 2 or 4, characterized in that A first connecting pipeline is fixedly connected between the first natural gas pipeline and the second natural gas pipeline between the ignition intake pipeline and the natural gas heater.

6. The energy saving device for natural gas solid caustic soda heating furnace for chlor-alkali production according to claim 3, characterized in that A first connecting pipeline is fixedly connected between the first natural gas pipeline and the second natural gas pipeline between the ignition intake pipeline and the natural gas heater.

7. The energy saving device for natural gas solid caustic soda heating furnace for chlor-alkali production according to claim 5, characterized in that The ignition inlet pipeline is fixedly connected to the second natural gas pipeline between the first connecting pipeline and the solid alkali heating furnace.

8. The energy-saving device for a natural gas solid alkali heating furnace for chlor-alkali production according to claim 6, characterized in that... The ignition inlet pipeline is fixedly connected to the second natural gas pipeline between the first connecting pipeline and the solid alkali heating furnace.

9. The energy-saving device for the natural gas solid caustic soda heating furnace of chlor-alkali production according to claim 7 or 8, characterized in that A first natural gas valve is fixedly installed on the first natural gas pipeline between the ignition inlet pipeline and the first connecting pipeline; a second natural gas valve is fixedly installed on the first natural gas pipeline between the first connecting pipeline and the natural gas heater; a third natural gas valve is fixedly installed on the second natural gas pipeline between the first connecting pipeline and the natural gas heater; a fourth natural gas valve is fixedly installed on the first connecting pipeline; a fifth natural gas valve is fixedly installed on the second connecting pipeline; a sixth natural gas valve is fixedly installed on the second natural gas pipeline between the second connecting pipeline and the solid alkali heater; and a seventh natural gas valve is fixedly installed on the ignition inlet pipeline between the second connecting pipeline and the solid alkali heater.

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