Supply system for absorbent in wet desulphurization tower

Abstract

The utility model relates to a supply system for an absorbent in a wet desulphurization tower. According to the supply system, a slurry collecting device, a pH detection branch line, an SO2 detection branch line and a slurry circulation main line are arranged on each spraying layer of the absorption tower; through the combined action of the slurry collecting device, the pH detection branch line and the pH detection device, the pH value of slurry in each spraying layer can be accurately monitored, and through the combined action of the SO2 detection branch line and the SO2 detection device, the SO2 concentration of flue gas in each spraying layer can be accurately monitored. Moreover, according to the pH value of the slurry in each spraying layer and the SO2 concentration data of the flue gas, the addition amount of the absorbent in each spraying layer is independently adjusted, and the problem of mismatched absorbent supply caused by single-point control of the absorbent in the prior art can be avoided.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of flue gas desulfurization, and in particular to a supply system of absorbent in a wet desulfurization tower. BACKGROUND

[0002] Industrial flue gas contains a large amount of sulfur dioxide, which will cause serious environmental pollution if directly discharged into the atmosphere, so desulfurization treatment must be carried out before the discharge of industrial flue gas. When the wet desulfurization technology is used for desulfurization treatment, limestone slurry needs to be supplied to the desulfurization tower through the slurry supply system. The limestone in the gypsum slurry reacts with SO2 to become gypsum, so that the pH value of the gypsum slurry in the desulfurization tower is stabilized within a certain range. When the slurry supply system fails and cannot supply limestone slurry, the pH value will decrease, resulting in a decrease in desulfurization efficiency.

[0003] CN102188894A discloses a flue gas desulfurization absorbent supply method and system, which comprises: supplying desulfurization absorbent to the desulfurization absorption tower by using a slurry supply device; obtaining the pH value of the gypsum slurry in the desulfurization absorption tower; determining whether the obtained pH value is lower than the preset minimum pH value; if so, controlling the standby slurry supply device to supply desulfurization absorbent to the pit of the desulfurization absorption tower. When the pH value of the gypsum slurry in the absorption tower is too low due to the failure of the desulfurization absorbent supply system, the flue gas desulfurization absorbent supply system can supply desulfurization absorbent to the pit of the desulfurization absorption tower in time to prevent SO2 in the flue gas from polluting the air.

[0004] Although the prior art can supply absorbent according to the pH value of the slurry, the slurry pH measurement is single-point measurement, which cannot accurately reflect the true pH value of the slurry in the desulfurization tower, and the supply point of the absorbent is also single-point supply, so the absorbent cannot uniformly enter the slurry in the absorption tower, resulting in over-supply of the absorbent and even affecting the quality of gypsum. UTILITY MODEL CONTENTS

[0005] The utility model aims at providing a supply system of absorbent in a wet desulfurization tower to solve the problem of mismatched supply of absorbent caused by inaccurate slurry pH value and single-point control of absorbent in the prior art.

[0006] In order to achieve the above-mentioned purpose, the utility model provides a supply system of absorbent in a wet desulfurization tower, which comprises a desulfurization tower, a pH detection unit, a SO2 detection unit and an absorbent supply unit.

[0007] The pH detection unit comprises a slurry collecting device, a pH detection main line, a pH detection branch line and a pH detection device arranged on the pH detection branch line.

[0008] The SO2 detection unit comprises an SO2 detection main line, an SO2 detection branch line, and an SO2 detection device arranged on the SO2 detection branch line.

[0009] The absorbent supply unit comprises a slurry circulation main line, a circulation pump arranged on the slurry circulation main line, and a spray flow regulating valve arranged on the slurry circulation main line.

[0010] Each spray layer of the desulfurization tower is configured with a slurry collecting device, a pH detection branch line, an SO2 detection branch line, and a slurry circulation main line; the slurry collecting device is arranged on the inner wall of each spray layer to form a slurry collecting chamber.

[0011] The inlet of the pH detection branch line extends to the slurry collecting chamber of the slurry collecting device; the inlet of the SO2 detection branch line extends to the internal chamber of the spray layer; the inlet of the slurry circulation main line is in communication with the outlet of the desulfurization slurry pool in the desulfurization tower, and the outlet of the slurry circulation main line is in communication with the inlet of the spray device of the desulfurization tower.

[0012] The outlet of the pH detection branch line is in communication with the inlet of the pH detection main line; the outlet of the pH detection main line is used to be in communication with a pit; the outlet of the SO2 detection branch line is in communication with the inlet of the SO2 detection main line; and the outlet of the SO2 detection main line is used to be in communication with an absorption tower.

[0013] Optionally, the slurry collecting device is formed as a cylinder body with an opening to form the slurry collecting chamber in the cylinder body; the cross section of the slurry collecting device along the radial direction of the cylinder body is a semicircular cross section; and the angle α between the axial direction of the cylinder body and the inner wall of the desulfurization tower is 70-80°.

[0014] Optionally, the diameter of the semicircular cross section is 100-150 mm, and the length of the slurry collecting device is 500-600 mm.

[0015] Optionally, the slurry collecting device is arranged below the spray device in the spray layer corresponding to the slurry collecting device; and the distance between the opening of the slurry collecting device and the spray device is 500-600 mm.

[0016] Optionally, the inlet of the SO2 detection branch line is arranged below the spray device in the spray layer corresponding to the SO2 detection branch line; and the distance between the inlet of the SO2 detection branch line and the spray device is 200-300 mm.

[0017] Optionally, the length of the SO2 detection branch line extending to the internal chamber of the spray layer is 100-200 mm.

[0018] Optionally, the number of spray layers in the desulfurization tower is four.

[0019] Optionally, the spray layers of the desulfurization tower are sequentially a first spray layer, a second spray layer, a third spray layer, and a fourth spray layer from bottom to top.

[0020] The desulfurization slurry pools of the desulfurization tower are sequentially a first slurry pool, a second slurry pool, a third slurry pool, and a fourth slurry pool from top to bottom.

[0021] The first spray layer is in communication with the first slurry pool through a slurry circulation main line.

[0022] The second spray layer is in communication with the second slurry pool through a slurry circulation main line.

[0023] The third spray layer is in communication with the third slurry pool through a slurry circulation main line.

[0024] The fourth spray layer is in communication with the fourth slurry pool through a slurry circulation main line.

[0025] Optionally, the supply system further comprises a DCS control unit.

[0026] The DCS control unit is electrically connected with the pH detection device, the SO2 detection device, and the spray flow regulating valve, for accepting the pH signal and the SO2 signal of the pH detection device and the SO2 detection device corresponding to each spray layer, and adjusting the opening of the spray flow regulating valve corresponding to each spray layer according to the pH signal and the SO2 signal.

[0027] Optionally, a fresh limestone slurry branch line is arranged on the slurry circulation main line, and an inlet of the fresh limestone slurry branch line is in communication with a fresh limestone source, so that fresh limestone slurry can enter the slurry circulation main line.

[0028] A liquid supplement regulating valve is arranged on the fresh limestone slurry branch line.

[0029] The DCS control unit is electrically connected with the pH detection device and the liquid supplement regulating valve, for accepting the pH signal of the pH detection device corresponding to each spray layer, and adjusting the opening of the liquid supplement regulating valve corresponding to each spray layer according to the pH signal.

[0030] By the technical scheme, one slurry collecting device and one pH detection branch line, one SO2 detection branch line and one slurry circulation main line are arranged in each spray layer of the absorption tower; through the joint action of the slurry collecting device, the pH detection branch line and the pH detection device, the pH value of the slurry in each spray layer can be accurately monitored, and through the joint action of the SO2 detection branch line and the SO2 detection device, the SO2 concentration of the flue gas in each spray layer can be accurately monitored. Moreover, according to the slurry pH value and the SO2 concentration data in each spray layer, the addition amount of the absorbent in each spray layer is independently adjusted, and the problem of mismatched supply of the absorbent caused by single-point control of the absorbent in the prior art can be avoided.

[0031] Other features and advantages of the present application will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0032] The accompanying drawings are included to provide a further understanding of the present application, and constitute a part of the specification, and are used together with the following detailed description to explain the present application, but do not constitute a limitation on the present application. In the drawings:

[0033] Figure 1 is a schematic diagram of a slurry collecting device according to the present application.

[0034] Figure 2 is a schematic diagram of a cross section of the slurry collecting device along the radial direction of the cylinder.

[0035] BRIEF DESCRIPTION OF DRAWINGS

[0036] 1 desulfurization tower; 2 pH detection main line; 3 pH detection branch line; 4 pH detection device; 5 slurry collecting device; 6 pit; 7 SO2 detection branch line; 8 SO2 detection main line; 9 SO2 detection device; 10 absorption tower; 11 slurry circulation main line; 12 circulating pump; 13 fresh limestone slurry branch line;

[0037] A first spray layer; B second spray layer; C third spray layer; D fourth spray layer; E first slurry pool; F second slurry pool; G third slurry pool; H fourth slurry pool. DETAILED DESCRIPTION

[0038] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0039] In the present application, unless otherwise stated, the orientation words such as "up" and "down" generally refer to the up and down of the device in the normal use state, for example, with reference to Figure 1The terms "first", "second", "third", "fourth" are only used for description purpose and cannot be understood as indicating or implying relative importance or implying the number of the indicated technical features. Therefore, the features defined as "first", "second", "third", "fourth" can explicitly or implicitly include one or more of the features. In the description of the utility model, the meaning of "multiple" is two or more than two, unless otherwise specifically limited.

[0040] As shown in Figure 1 The utility model provides a kind of supply system of absorbent in wet desulfurization tower, which includes desulfurization tower 1, pH detection unit, SO2 detection unit and absorbent supply unit;

[0041] The pH detection unit includes slurry collecting device 5, pH detection main line 2, pH detection branch line 3 and pH detection device 4 arranged on the pH detection branch line 3;

[0042] The SO2 detection unit includes SO2 detection main line 8, SO2 detection branch line 7 and SO2 detection device 9 arranged on the SO2 detection branch line 7;

[0043] The absorbent supply unit includes slurry circulation main line 11, circulating pump 12 arranged on the slurry circulation main line 11 and spray flow regulating valve arranged on the slurry circulation main line 11;

[0044] Each spray layer of the desulfurization tower 1 is configured with one slurry collecting device 5, one pH detection branch line 3, one SO2 detection branch line 7 and one slurry circulation main line 11;The slurry collecting device 5 is arranged on the inner wall of each layer of spray layer to form a slurry collecting chamber;

[0045] The inlet of the pH detection branch line 3 extends to the slurry collecting chamber of the slurry collecting device 5;The inlet of the SO2 detection branch line 7 extends to the internal chamber of the spray layer;The inlet of the slurry circulation main line 11 communicates with the outlet of the desulfurization slurry pool in the desulfurization tower 1, and the outlet of the slurry circulation main line 11 communicates with the inlet of the spray device of the desulfurization tower 1;

[0046] The outlet of the pH detection branch line 3 communicates with the inlet of the pH detection main line 2;The outlet of the pH detection main line 2 is used for communicating with pit 6;The outlet of the SO2 detection branch line 7 communicates with the inlet of the SO2 detection main line 8;The outlet of the SO2 detection main line is used for communicating with absorption tower 10.

[0047] By the technical scheme, one slurry collecting device 5 and one pH detection branch 3, one SO2 detection branch 7 and one slurry circulating main line 11 are arranged in each spray layer of the absorption tower 10; through the joint action of the slurry collecting device 5, the pH detection branch 3 and the pH detection device 4, the pH value of the slurry in each spray layer can be accurately monitored, and through the joint action of the SO2 detection branch 7 and the SO2 detection device 9, the SO2 concentration of the flue gas in each spray layer can be accurately monitored. Moreover, according to the pH value of the slurry and the SO2 concentration data of the flue gas in each spray layer, the addition amount of the absorbent in each spray layer is independently adjusted, so that the problem of mismatched supply of the absorbent caused by single-point control of the absorbent in the prior art can be avoided.

[0048] In an embodiment, the desulfurization tower 1 is a conventional selection in the art, and no special requirement is made in the present application. It should be noted that the desulfurization tower 1 of the present application comprises a plurality of spray layers. In this embodiment, the spray layer refers to a section where the spraying device is located and a partial area below the section.

[0049] In an embodiment, the number of spray layers in the desulfurization tower 1 is 2-5.

[0050] In a preferred embodiment, the number of spray layers in the desulfurization tower 1 is 4.

[0051] In a specific embodiment, the spray layers of the desulfurization tower 1 are sequentially a first spray layer A, a second spray layer B, a third spray layer C and a fourth spray layer D from bottom to top.

[0052] In an embodiment, the lower part of the desulfurization tower 1 forms a slurry collecting chamber for storing the mixed slurry of limestone and gypsum obtained after reaction with sulfur dioxide.

[0053] In an embodiment, the desulfurization slurry pool of the desulfurization tower 1 is sequentially divided into a first slurry pool E, a second slurry pool F, a third slurry pool G and a fourth slurry pool H from top to bottom.

[0054] In an embodiment, the first spray layer A is communicated with the first slurry pool E through one slurry circulating main line 11; the second spray layer B is communicated with the second slurry pool F through one slurry circulating main line 11; the third spray layer C is communicated with the third slurry pool G through one slurry circulating main line 11; and the fourth spray layer D is communicated with the fourth slurry pool H through one slurry circulating main line 11.

[0055] In an embodiment, the slurry circulating main line 11 is provided with a fresh limestone slurry branch 13, one end of the fresh limestone slurry branch 13 is communicated with a fresh limestone source, and the other end of the fresh limestone slurry branch 13 is communicated with the slurry circulating main line 11.

[0056] In one embodiment, the fresh limestone slurry branch 13 is provided with a liquid supplement regulating valve.

[0057] In the above embodiment, by providing the fresh limestone slurry branch 13, fresh limestone slurry can be supplemented when the pH value of the circulating slurry does not meet the standard, and by providing the liquid supplement regulating valve, the amount of fresh limestone added can be adjusted to achieve stable and safe addition of limestone slurry.

[0058] As shown in Figure 2 The slurry collecting device 5 is formed as a cylinder with an opening to form the slurry collecting chamber inside the cylinder, and the cross section of the slurry collecting device along the radial direction of the cylinder is a semicircular cross section. In this embodiment, the cylinder of the slurry collecting device 5 and the inner wall of the desulfurization tower 1 form a slurry collecting chamber that can accommodate slurry.

[0059] In one embodiment, the size of the slurry collecting device 5 includes: the diameter of the semicircular cross section is 100-150 mm; the length of the slurry collecting device 5 is 500-600 mm. In this embodiment, the slurry collecting device 5 with appropriate size is used, and the slurry it accommodates can meet the amount required for measurement testing by the pH detection device 4.

[0060] In one embodiment, the opening direction of the slurry collecting device 5 is upward, and the angle α between the axial direction of the cylinder of the slurry collecting device 5 and the inner wall of the desulfurization tower 1 is 70-80°. In this embodiment, the slurry collecting device 5 is arranged upward at a certain angle, so that the mixture of gypsum and limestone produced after desulfurization can enter the slurry collecting device 5 through the opening thereof and be stored in the slurry collecting chamber. When the pH value starts to be measured, the accommodated slurry enters the pH detection main line 2 through the pH detection branch line 3, and then enters the pit 6.

[0061] In one embodiment, the slurry collecting device 5 is arranged below the spraying device in the spraying layer corresponding to the slurry collecting device 5, and the distance between the inlet of the slurry collecting device 5 and the spraying device is 500-600 mm.

[0062] In one embodiment, the inlet of the pH detection branch line 3 extends into the slurry collecting chamber, and the inlet of the pH detection branch line 3 is close to the bottom of the slurry collecting chamber.

[0063] In one embodiment, according to the actual production needs and the size of the desulfurization tower 1, multiple slurry collecting devices 5 can be arranged in each spraying layer, and the multiple slurry collecting devices 5 are arranged at different positions of the spraying layer.

[0064] In one embodiment, each slurry collecting device 5 is provided with a pH detection branch 3.

[0065] In the above embodiment, when the slurry collecting device 5 and the pH detection branch 3 are arranged at a suitable position of the spray layer, the slurry sprayed by the spraying device of the spray layer can fully react with the sulfur dioxide in the spray layer, and is not excessively reacted by the gas phase under the spray layer, and the slurry collected at the above position can represent the true pH value of the slurry in the spray layer, thereby further improving the accuracy of pH detection.

[0066] In one embodiment, the pH detection device 4 used in the utility model is a conventional selection in the field, and no special requirement is made in the application.

[0067] In one embodiment, a program-controlled valve is further arranged on the pH detection branch 3, so that the slurry collected in the slurry collecting device 5 is subjected to pH detection through the pH detection branch 3 at intervals.

[0068] In one embodiment, the inlet of the SO2 detection branch 7 is arranged below the spraying device in the spray layer corresponding to the SO2 detection branch 7, and the distance between the inlet of the SO2 detection branch 7 and the spraying device is 200-300 mm. In the embodiment, the inlet of the SO2 detection branch 7 is relatively close to the spraying device, and the closer to the spraying device, the higher the removal rate of sulfur dioxide in the flue gas, and the less the content of sulfur dioxide in the flue gas, so that the sulfur dioxide detection of the flue gas can better reflect the desulfurization effect of each bed layer.

[0069] In one embodiment, the SO2 detection branch 7 extends to the internal chamber of the spray layer by a length of 100-200 mm. In the embodiment, the SO2 detection branch 7 is extended to the internal chamber of the spray layer by a certain length, so as to avoid that the slurry sprayed by the spraying device enters the SO2 detection branch 7 and accumulates in the pipeline, thereby causing blockage and other adverse phenomena.

[0070] In one embodiment, the inlet of the SO2 detection branch 7 can be downward.

[0071] In one embodiment, the SO2 detection device 9 used in the utility model is a conventional selection in the field, and no special requirement is made in the application.

[0072] In one embodiment, the supply system further comprises a DCS control unit for automatically adjusting the spraying amount of the spraying flow of the corresponding spray layer according to the pH value and the SO2 concentration.

[0073] In one embodiment, the DCS control unit is electrically connected with the pH detection device 4, the SO2 detection device 9 and the spray flow regulating valve, for receiving the pH signal and the SO2 signal of the pH detection device 4 and the SO2 detection device 9 corresponding to each spray layer, and adjusting the opening of the spray flow regulating valve corresponding to each spray layer according to the signal.

[0074] In one embodiment, the DCS control unit is electrically connected with the pH detection device 4 and the liquid supplement regulating valve, for receiving the pH signal of the pH detection device 4 corresponding to each spray layer, and adjusting the opening of the liquid supplement regulating valve corresponding to each spray layer according to the signal.

[0075] In the above embodiment, the circulating slurry of each spray layer is taken from different positions of the desulfurization slurry pool, and the proportion of limestone and gypsum in the slurry of each spray layer and the spray amount of the circulating slurry need to be independently adjusted due to the different proportions of limestone and gypsum in the slurry of different positions. The DCS control unit flexibly adjusts the opening of the spray flow regulating valve corresponding to each spray layer according to the detected pH value and SO2 concentration of each spray layer, thereby realizing independent adjustment of the spray flow of each spray layer. The DCS control unit flexibly adjusts the opening of the liquid supplement regulating valve corresponding to each spray layer according to the detected pH value of each spray layer, thereby realizing independent adjustment of the proportion of limestone and gypsum in the slurry sprayed in each spray layer.

[0076] The preferred embodiments of the present application are described in detail above in combination with the drawings, but the present application is not limited to the specific details in the above embodiments, and various simple modifications can be made to the technical solutions of the present application within the technical concept of the present application, and these simple modifications all belong to the protection scope of the present application.

[0077] In addition, it should be noted that each specific technical feature described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present application will not further describe various possible combination manners.

[0078] In addition, various different embodiments of the present application can also be combined in any manner, as long as they do not deviate from the technical concept of the present application, and they should also be considered as disclosed content of the present application.

Claims

1. A supply system for absorbent in a wet desulfurization tower, characterized in that, The supply system includes a desulfurization tower, a pH detection unit, an SO2 detection unit, and an absorbent supply unit; The pH detection unit includes a slurry collection device, a pH detection main line, a pH detection branch line, and a pH detection device installed on the pH detection branch line. The SO2 detection unit includes an SO2 detection main line, an SO2 detection branch line, and an SO2 detection device installed on the SO2 detection branch line. The absorbent supply unit includes a slurry circulation main line, a circulation pump installed on the slurry circulation main line, and a spray flow regulating valve installed on the slurry circulation main line. Each spray layer of the desulfurization tower is equipped with a slurry collection device, a pH detection branch line, an SO2 detection branch line, and a slurry circulation main line; the slurry collection device is set on the inner wall of each spray layer to form a slurry collection chamber; The inlet of the pH detection branch extends to the slurry collection chamber of the slurry collection device; the inlet of the SO2 detection branch extends to the internal chamber of the spray layer; the inlet of the slurry circulation main line is connected to the outlet of the desulfurization slurry pool in the desulfurization tower, and the outlet of the slurry circulation main line is connected to the inlet of the spray device of the desulfurization tower. The outlet of the pH detection branch line is connected to the inlet of the pH detection main line; the outlet of the pH detection main line is used to connect to the pit; the outlet of the SO2 detection branch line is connected to the inlet of the SO2 detection main line; the outlet of the SO2 detection main line is used to connect to the absorption tower.

2. The supply system according to claim 1, characterized in that, The slurry collection device is formed as a cylinder with an opening to form the slurry collection chamber inside the cylinder; The slurry collection device has a semi-circular cross-section along the radial direction of the cylinder. The angle α formed between the axial direction of the cylinder and the inner wall of the desulfurization tower is 70~80°.

3. The supply system according to claim 2, characterized in that, The diameter of the semi-circular cross-section is 100~150mm, and the length of the slurry collection device is 500~600mm.

4. The supply system according to claim 1, characterized in that, The slurry collection device is located below the spraying device in the spraying layer corresponding to the slurry collection device; The distance between the opening of the slurry collection device and the spraying device is 500~600mm.

5. The supply system according to claim 1, characterized in that, The entrance to the SO2 detection branch is located below the spray device in the spray layer corresponding to the SO2 detection branch. The distance between the inlet of the SO2 detection branch and the spray device is 200~300mm.

6. The supply system according to claim 1, characterized in that, The length of the SO2 detection branch extending into the internal cavity of the spray layer is 100~200mm.

7. The supply system according to claim 1, characterized in that, The desulfurization tower has four spray layers.

8. The supply system according to claim 7, characterized in that, The spray layers of the desulfurization tower are, from bottom to top, the first spray layer, the second spray layer, the third spray layer and the fourth spray layer; The desulfurization slurry pool of the desulfurization tower is divided into a first slurry pool, a second slurry pool, a third slurry pool and a fourth slurry pool from top to bottom; The first spray layer is connected to the first slurry tank through a slurry circulation main line; The second spray layer is connected to the second slurry tank via a slurry circulation main line; The third spray layer is connected to the third slurry tank through a slurry circulation main line; The fourth spray layer is connected to the fourth slurry tank via a slurry circulation main line.

9. The supply system according to claim 1, characterized in that, The supply system also includes a DCS control unit; The DCS control unit is electrically connected to the pH detection device, the SO2 detection device, and the spray flow regulating valve. It is used to receive the pH signal and SO2 signal from the pH detection device and the SO2 detection device corresponding to each spray layer, and adjust the opening degree of the spray flow regulating valve corresponding to each spray layer according to the pH signal and SO2 signal.

10. The supply system according to claim 9, characterized in that, A fresh limestone slurry branch line is provided on the slurry circulation main line. The inlet of the fresh limestone slurry branch line is used to connect with a fresh limestone source so that fresh limestone slurry can enter the slurry circulation main line. The fresh limestone slurry branch line is equipped with a liquid replenishment regulating valve; The DCS control unit is electrically connected to the pH detection device and the replenishment regulating valve, and is used to receive the pH signal from the pH detection device corresponding to each spray layer, and adjust the opening degree of the replenishment regulating valve corresponding to each spray layer according to the pH signal.

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