Comprehensive utilization system for acid-making steam

Abstract

The utility model discloses a comprehensive utilization system for acid-making steam, and belongs to the technical field of phosphorus chemical industry. Comprising a desalted water preparation system, a steam pipe network, a steam power generation device and a temperature sensor, the desalted water preparation system comprises a raw water storage tank, a desalted water preparation device and a deaerator which are sequentially connected, a sulfuric acid production system comprises a sulfur melting device, a waste heat boiler and a heat energy recovery device, and the deaerator is connected with the waste heat boiler and the heat energy recovery device. A steam outlet of the heat energy recovery device is connected with a steam pipe network; the steam pipe network is connected with the sulfur melting device and the deaerator; an air inlet of the steam power generation device is connected with a steam outlet of the waste heat boiler, and an air outlet of the steam power generation device is connected with a steam pipe network to supply power to the desalted water preparation system and the sulfuric acid production system; a temperature sensor and a steam inlet pipe are arranged in the raw water storage tank; a control valve is arranged on the steam inlet pipe, is connected with a steam pipe network, and is communicated below the liquid level; the control valve is opened only when the temperature detected by the temperature sensor is lower than the preset temperature.

Description

Technical Field

[0001] The utility model belongs to the technical field of phosphorus chemical industry, and particularly relates to a comprehensive utilization system of acid-making steam, which can reduce energy consumption. Background Art

[0002] The sulfuric acid plant mainly consists of two processes: sulfur burning conversion and absorption. The sulfur burning conversion process completes the process reaction of sulfur combustion to generate SO2 and catalytic oxidation of SO2 to generate SO3, and the absorption process uses concentrated sulfuric acid to absorb SO3 to obtain sulfuric acid.

[0003] For example, the patent with application number CN200910208733.3 discloses a method and device for preparing sulfuric acid, which includes: burning liquid sulfur and pure oxygen in a sulfur incinerator and discharging furnace gas after combustion; using the heat released by the combustion to heat the boiler feed water in the boiler coil and / or the steam in the steam superheater coil arranged in the sulfur incinerator; passing the furnace gas into a converter containing a catalyst for reaction, so that sulfur dioxide and pure oxygen in the furnace gas react to generate sulfur trioxide, and the converted gas discharged after the reaction is cooled by heat exchange and then passed into an absorption tower, and the sulfur trioxide is absorbed by concentrated sulfuric acid to generate sulfuric acid.

[0004] For example, the patent with application number CN202221794168.0 discloses a device for improving the steam production rate of high-temperature and high-pressure steam in sulfuric acid production, which includes a sulfur incinerator, a high-temperature absorption tower and a converter. The output end of the sulfur incinerator is connected to the converter through a high-pressure waste heat boiler. The converters are sequentially divided into section I, section II, section III and section IV from top to bottom; the process gas outlet of section I of the converter is connected to section II of the converter through a high-temperature superheater, the process gas outlet of section II of the converter is connected to section III of the converter through a hot-to-hot heat exchanger, and the process gas outlet of section III of the converter is sequentially connected to the bottom of the high-temperature absorption tower through a cold-to-hot heat exchanger and an air preheater.

[0005] Sulfur combustion can generate a large amount of heat, and the flue gas temperature is above 1000℃. Before conversion, the flue gas can be cooled and steam can be generated through waste heat boilers and heat recovery devices (usually heat exchangers or boilers). Usually, waste heat boilers generate medium-pressure steam, and heat recovery devices generate low-pressure steam. The low-pressure steam is directly sent to the steam network, and the medium-pressure steam is sent to the steam network after decompression. The steam in the steam network is sent to the sulfur melting device and the ammonium phosphate production system for use. Figure 1 The figure is a functional block diagram of the existing comprehensive utilization system of acid-making steam. When the applicant adopts the existing comprehensive utilization system of acid-making steam, the applicant finds the following two problems:

[0006] (1) Using a temperature and pressure reducer to reduce pressure is a waste of energy;

[0007] (2) When the reverse osmosis filter is at low temperature (such as in winter), the wastewater rate is higher. Utility Model Content

[0008] The embodiment of the utility model provides a comprehensive utilization system of acid steam. In this system, medium-pressure steam is converted into low-pressure steam while generating electricity to be incorporated into the steam network, providing electricity for the production plant. In winter, when preparing desalted water, raw water is heated by steam (with surplus) to reduce the generation of concentrated water. The technical solution is as follows:

[0009] The utility model provides a comprehensive utilization system of acid-making steam, which includes a desalted water preparation system, a steam network, a steam power generation device and a temperature sensor. The desalted water preparation system includes a raw water storage tank, a desalted water preparation device and a deaerator connected in sequence. The sulfuric acid production system includes a sulfur melting device, a waste heat boiler and a heat recovery device. The deaerator is connected to the waste heat boiler and the heat recovery device. The steam outlet of the heat recovery device is connected to the steam network, and the steam network is connected to the sulfur melting device and the deaerator; the air inlet of the steam power generation device is connected to the steam outlet of the waste heat boiler, and the air outlet is connected to the steam network, which supplies power to the desalted water preparation system and the sulfuric acid production system; the raw water storage tank is provided with a temperature sensor and a steam inlet pipe; the steam inlet pipe is provided with a control valve, which is connected to the steam network and is introduced below the liquid surface; the control valve is opened only when the temperature detected by the temperature sensor is lower than a predetermined temperature.

[0010] Furthermore, the steam pipeline network in the embodiment of the utility model provides steam for the ammonium phosphate production system, and the steam power generation device provides power for the phosphoric acid production system and the ammonium phosphate production system.

[0011] Among them, the sulfuric acid production system in the embodiment of the utility model includes a sulfur melting device, a sulfur incinerator, a waste heat boiler, a heat recovery device, a converter and an absorption tower which are connected in sequence.

[0012] Among them, the desalted water preparation device in the embodiment of the utility model includes a concentrated water storage tank and a multi-media filter, an activated carbon filter, a security filter, a reverse osmosis filter, an intermediate water tank, an ion exchange unit and a desalted water storage tank connected in sequence, the concentrated water storage tank is connected to the concentrated water outlet of the reverse osmosis filter, and the desalted water storage tank is connected to the deaerator.

[0013] Furthermore, the comprehensive utilization system in the embodiment of the utility model also includes a liquid level meter and a temperature controller, the liquid level meter is arranged in the desalted water storage tank, the control valve is an electrically controlled valve, and the electrically controlled valve, temperature sensor and liquid level meter are all electrically connected to the temperature controller; the control valve is opened only when the temperature detected by the temperature sensor is lower than the predetermined temperature and the water level of the desalted water storage tank is lower than the predetermined water level.

[0014] Among them, the steam power generation device in the embodiment of the utility model is a steam turbine generator, whose input steam pressure is 3.5-4.5Mpa, and whose output steam pressure is less than 0.7Mpa.

[0015] Specifically, the output of the sulfuric acid production system in the embodiment of the utility model is 30Wt / a, and the power of the steam power generation device is 7000-8000KW / h.

[0016] Specifically, the output of the sulfuric acid production system in the embodiment of the utility model is 30Wt / a, the volume of the raw water storage tank is 70-100 cubic meters, and the inner diameter of the steam inlet pipe is 40-70mm.

[0017] The beneficial effects of the technical solution provided by the embodiment of the utility model are as follows: the embodiment of the utility model provides a comprehensive utilization system of acid-making steam, in which medium-pressure steam is converted into low-pressure steam while generating electricity to be incorporated into the steam network, providing electric energy for the production plant. In winter, when preparing desalted water, raw water is heated by steam (with surplus) to reduce the generation of concentrated water, thereby generating more desalted water, which actually saves energy consumption and reduces the cost of wastewater treatment (treating concentrated water). BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is the principle block diagram of the existing comprehensive utilization system of acid-making steam;

[0019] Figure 2 Schematic diagram of the comprehensive utilization system of acid-making steam in the embodiment of the utility model;

[0020] Figure 3 It is the principle block diagram of the desalted water preparation system;

[0021] Figure 4 This is a schematic diagram of the power supply of a steam power generation device. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the utility model clearer, the utility model will be further described in detail below with reference to the accompanying drawings.

[0023] Example 1

[0024] See also Figure 2-4Embodiment 1 provides a comprehensive utilization system for acid-making steam, which includes a desalted water preparation system, a steam network, a steam power generation device, and a temperature sensor (thermometer or electronic sensor, etc.). The desalted water preparation system includes a pretreatment device (specifically, a sedimentation tank), a raw water storage tank, a desalted water preparation device, and a deaerator, etc., which are sequentially connected through pipelines. The desalted water preparation device includes a concentrated water storage tank (usually output to a wastewater treatment system) and a multi-media filter, an activated carbon filter, a security filter, a reverse osmosis filter, an intermediate water tank, an ion exchange unit, and a desalted water storage tank, etc., which are sequentially connected through pipelines. The concentrated water storage tank is connected to the concentrated water outlet of the reverse osmosis filter through a pipeline, and the desalted water storage tank is connected to the deaerator through a pipeline. The sulfuric acid production system includes a sulfur melting device, a sulfur incinerator, a waste heat boiler, a heat recovery device (specifically, an HRS boiler), a converter and an absorption tower, etc., which are connected in sequence through pipelines. The sulfur melting device includes multiple filters and multiple heating tanks (including a fast sulfur melting tank, a coarse filter tank, an auxiliary filter tank, an intermediate tank or a fine filter tank, etc., which are provided with a steam heating jacket and a coil heater). The deaerator is connected to the waste heat boiler and the heat recovery device through pipelines to provide oxygen-free desalted water. The ammonium phosphate production system includes a reactor, a concentration device, a molding device (granulation or powder spraying device) and an exhaust gas treatment device. The steam outlet (output low-pressure steam) of the heat recovery device is directly connected to the steam network through a pipeline; the steam outlet (output medium-pressure steam) of the waste heat boiler is connected to the air inlet of the steam power generation device through a pipeline, and the air outlet (output low-pressure steam) of the steam power generation device is connected to the steam network through a pipeline. The steam power generation device supplies power to the desalted water preparation system, sulfuric acid production system, phosphoric acid production system, ammonium phosphate production system and other structures. The steam network is connected to the sulfur melting device (specifically the heating tank), the deaerator and the phosphate ammonium production system (specifically the reactor and the concentration device) to provide heating steam for the sulfur melting device, the deaerator and the phosphate ammonium production system. A temperature sensor and a steam inlet pipe are provided in the raw water storage tank. A control valve is provided on the steam inlet pipe, which is connected to the steam network and is passed below the liquid surface in the raw water storage tank (specifically passed into the lower part of the raw water storage tank). The control valve (manual control or automatic control) is opened only when the temperature sensor detects that the temperature of the raw water is lower than the predetermined temperature (determined according to the working temperature of the reverse osmosis filter, specifically, the low value of the working temperature of the reverse osmosis filter plus 1-5°C (the heated raw water will be slightly cooled when it reaches the reverse osmosis filter)). Specifically, in winter, the temperature of the raw water in the raw water storage tank is controlled to be 23-46°C, preferably 25-28°C, to ensure that the reverse osmosis filter has a lower wastewater rate. Taking Yichang in winter as an example, when the raw water temperature is controlled at 25-28℃, the wastewater rate of the reverse osmosis filter is about 30%; if no steam is introduced for heating, the wastewater rate of the reverse osmosis filter is 40-45%.

[0025] Among them, the steam power generation device in the embodiment of the utility model is a steam turbine generator, whose input steam pressure is 3.5-4.5Mpa, and whose output steam pressure is less than 0.7Mpa.

[0026] Specifically, the output of the sulfuric acid production system in the embodiment of the utility model is 30Wt / a, the power of the steam power generation device is 7000-8000KW / h, the volume of the raw water storage tank is 70-100 cubic meters, and the inner diameter of the steam inlet pipe is 40-70mm.

[0027] Example 2

[0028] See also Figure 3 , Example 2 provides a comprehensive utilization system for acid steam, and its structure is basically the same as that of Example 1, except that: the comprehensive utilization system provided in this embodiment adopts an automatic control method to open and close the control valve, and the comprehensive utilization system in this embodiment also includes a liquid level meter (specifically an electronic liquid level meter) and a temperature controller (conventional structure), the liquid level meter is arranged in the desalted water storage tank, the temperature sensor is an electronic thermometer, and the control valve is an electric control valve. The electric control valve, the temperature sensor and the liquid level meter are all electrically connected to the temperature controller; the temperature sensor controls the electric control valve according to the detection results of the temperature sensor and the liquid level meter. The control valve is opened only when the temperature detected by the temperature sensor is lower than the predetermined temperature (such as lower than 23°C) and the water level of the desalted water storage tank is lower than the predetermined water level (at this time, the amount of desalted water is insufficient and desalted water needs to be prepared), and other structures work in coordination.

[0029] Example 3

[0030] Example 3 provides a comprehensive utilization system of acid-making steam, the structure of which is basically the same as that of Example 1, except that the output of the sulfuric acid production system in the embodiment of the utility model is 30Wt / a. The input steam pressure of the steam power generation device is 3.82Mpa, the output steam pressure is 0.5Mpa, and the power is 7500KW / h. The specifications of the raw water storage tank are 5m in diameter and 5m in height. The specifications of the steam inlet pipe are DN50.

[0031] In this embodiment, pumps, fans, flow meters or valves are arranged on the pipelines between the structures as required.

[0032] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A comprehensive utilization system of acid-making steam, comprising a desalted water preparation system and a steam network, wherein the desalted water preparation system comprises a raw water storage tank, a desalted water preparation device and a deaerator connected in sequence, and a sulfuric acid production system comprises a sulfur melting device, a waste heat boiler and a heat recovery device, wherein the deaerator is connected to the waste heat boiler and the heat recovery device, the steam outlet of the heat recovery device is connected to the steam network, and the steam network is connected to the sulfur melting device and the deaerator; characterized in that: The comprehensive utilization system also includes a steam power generation device and a temperature sensor; the air inlet of the steam power generation device is connected to the steam outlet of the waste heat boiler, and the air outlet is connected to the steam pipe network, which supplies power to the desalted water preparation system and the sulfuric acid production system; the raw water storage tank is provided with a temperature sensor and a steam inlet pipe; the steam inlet pipe is provided with a control valve, which is connected to the steam pipe network and is introduced below the liquid surface; the control valve is opened only when the temperature detected by the temperature sensor is lower than the predetermined temperature.

2. The comprehensive utilization system of acid-making steam according to claim 1, characterized in that: The steam pipeline network provides steam for the ammonium phosphate production system, and the steam power generation device provides power for the phosphoric acid production system and the ammonium phosphate production system.

3. The comprehensive utilization system of acid-making steam according to claim 1, characterized in that: The sulfuric acid production system comprises a sulfur melting device, a sulfur incinerator, a waste heat boiler, a heat energy recovery device, a converter and an absorption tower which are connected in sequence.

4. The comprehensive utilization system of acid-making steam according to claim 1, characterized in that: The desalted water preparation device comprises a concentrated water storage tank and a multi-media filter, an activated carbon filter, a security filter, a reverse osmosis filter, an intermediate water tank, an ion exchange unit and a desalted water storage tank connected in sequence; the concentrated water storage tank is connected to the concentrated water outlet of the reverse osmosis filter, and the desalted water storage tank is connected to a deaerator.

5. The comprehensive utilization system of acid-making steam according to claim 4, characterized in that: The comprehensive utilization system also includes a liquid level meter and a temperature controller. The liquid level meter is arranged in the desalted water storage tank. The control valve is an electrically controlled valve. The electrically controlled valve, the temperature sensor and the liquid level meter are all electrically connected to the temperature controller. The control valve is opened only when the temperature detected by the temperature sensor is lower than a preset temperature and the water level in the desalted water storage tank is lower than a preset water level.

6. The comprehensive utilization system of acid-making steam according to claim 1, characterized in that: The steam power generation device is a steam turbine generator, the input steam pressure of which is 3.5-4.5Mpa, and the output steam pressure of which is less than 0.7Mpa.

7. The comprehensive utilization system of acid-making steam according to claim 6, characterized in that: The output of the sulfuric acid production system is 30Wt / a, and the power of the steam power generation device is 7000-8000KW / h.

8. The comprehensive utilization system of acid-making steam according to claim 7, characterized in that: The output of the sulfuric acid production system is 30Wt / a, the volume of the raw water storage tank is 70-100 cubic meters, and the inner diameter of the steam inlet pipe is 40-70 mm.

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