Bubbling type quick lime digestion device and digestion method

Abstract

The invention provides a bubbling type quick lime digestion device and a digestion method. The device comprises a hollow base and a cylindrical reactor fixedly arranged at the center of the hollow base, in the upward direction of the hollow base, a product collecting tank and at least two overflow circular rings are annularly arranged on the side surface of the cylindrical reactor; the diameter of the product collecting groove is larger than that of the adjacent overflow circular ring, and the diameters of the overflow circular rings are gradually reduced in the direction of the product collecting groove. Limestone is digested in a bubbling mode, continuous digestion can be achieved, calcium hydroxide with the high specific surface area is obtained, and therefore the digestion efficiency is improved, energy consumption and pollution are reduced, operation is convenient, production efficiency is high, and the efficient uniform mixing capacity is achieved; the problems that in the prior art, blocky quick lime is buried in slaked lime powder, and unreacted particle impurities are doped in a finished product are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of calcium hydroxide production, and relates to a quicklime digestion device, in particular to a bubbling quicklime digestion device and a digestion method. Background Art

[0002] Calcium hydroxide is commonly known as slaked lime or hydrated lime, and its aqueous solution is called clear lime water. Calcium hydroxide has the general properties of an alkali and is a strong base. Calcium hydroxide is a binary strong base, but it is only slightly soluble in water. Calcium hydroxide is widely used in industrial flue gas desulfurization, but the direct purchase cost is high, so using a lime digestion reactor to digest quicklime with water to produce calcium hydroxide can reduce costs.

[0003] The digestion process of lime is one of the key steps in its industrial application, but the multi-stage digestion reactors currently used in industry generally have problems such as incomplete digestion, low efficiency, and uneven mixing. When in use, the traditional lime digestion reactor inputs quicklime and water into the digester, generates slaked lime through contact reaction, and finally outputs it from the discharge pipe. However, the inventors found during use that the unreacted block quicklime will be buried in the powder of slaked lime during the reaction, making it difficult to fully contact with water, resulting in incomplete reaction, and the finished product is doped with unreacted CaO impurities, affecting the subsequent storage and use of slaked lime. In order to solve the above problems, most industries usually fully crush the quicklime before adding it to avoid forming large blocks, so that it can fully contact and react with water in the digester, improve the digestion effect, but increase the electricity cost.

[0004] When preparing high specific surface area calcium hydroxide, there will be many problems in the digestion process. When the rotary drum digestion equipment is digested, the obtained slaked lime is not fully and thoroughly digested due to the lack of stirring and the solution existing in the equipment for a period of time. The impurity content is high. Therefore, how to improve the efficiency of lime digestion, reduce production costs, and avoid resource waste and secondary pollution in industrial production is essential. The traditional quicklime digester usually includes a digestion device and a water distribution device. After the water distribution device sprays water to the quicklime in the digester according to a certain water supply, the quicklime is strongly stirred in the digester through the rotation of the spiral agitator blades and gradually dissolved, digested, and matured. The stirring blades simultaneously push the digested quicklime forward. However, there are many challenges in actual operation, which affect the digestion efficiency and product quality. The core of the digestion device is a reaction chamber, in which the quicklime reacts chemically with water. It is usually a fixed or rotating reaction chamber, and there is no effective stirring mechanism inside, resulting in insufficient contact between the quicklime and water and uneven reaction. In the rotary drum digestion equipment, the residence time of the lime slurry in the reaction chamber is uneven, resulting in unstable quality of the generated calcium hydroxide. The water distribution device sprays water evenly on the quicklime through nozzles, but due to design or layout limitations, the water distribution may be uneven, affecting the digestion effect.

[0005] CN202320514965.7 discloses a lime digestion machine, which has a complex internal structure and time-consuming shutdown for cleaning; the digestions disclosed in CN202222598516.3, CN202222598516.3, etc. have problems such as high energy consumption, uneven stirring and difficult maintenance. At present, digestion reactors of different styles and functions have been disclosed in the prior art, and the efficiency of lime digestion has been improved through continuous improvement. However, there are still disadvantages such as incomplete digestion, low efficiency, presence of impurities, and uneven feeding.

[0006] Based on the above problems, it is necessary to provide an efficient, energy-saving and environmentally friendly limestone digestion method to solve the problems existing in the prior art that the lumps of quicklime are buried in the slaked lime powder, resulting in the inclusion of unreacted particulate impurities in the finished product. Summary of the invention

[0007] The object of the present invention is to provide a bubbling quicklime digestion device and digestion method. The device is a bubbling bed reactor for continuous digestion, which digests limestone by bubbling, can achieve continuous digestion, obtain high specific surface area calcium hydroxide, thereby improving digestion efficiency, reducing energy consumption and pollution, and is easy to operate, high in production efficiency, and has efficient mixing ability, solving the problems existing in the prior art that block quicklime is buried in slaked lime powder, resulting in the doping of unreacted granular impurities in the finished product.

[0008] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a bubbling quicklime digestion device, the device comprising a hollow base, and a cylindrical reactor fixedly arranged at the center of the hollow base;

[0010] In the direction upward from the hollow base, the side ring of the cylindrical reactor is provided with a product collecting groove and at least two overflow rings;

[0011] The diameter of the product collecting groove is greater than the diameter of the adjacent overflow ring, and the diameter of the overflow ring decreases step by step along the direction of the product collecting groove.

[0012] In the present invention, the digestion reaction of quicklime is carried out in a cylindrical reactor, and the emulsified slurry formed during the reaction overflows from the top of the cylindrical reactor to the overflow ring on the periphery of the cylindrical reactor. After at least two overflows, the digestion product slaked lime Ca(OH)2 slurry is obtained in the product collecting tank.

[0013] Among them, the purpose of setting at least two overflow rings is that the reactants overflow from the top of the cylindrical reactor into the overflow rings arranged in a stepped manner. When the reactants overflow in the upper overflow ring, they will flow to the lower overflow ring, ensuring that the reactants have enough residence time for full reaction and removing water-insoluble impurities such as limestone and aluminosilicates. The design of multiple overflow rings can improve the reaction efficiency and ensure that the lime is fully digested. Each layer of overflow rings plays a role of layered reaction and step-by-step flow.

[0014] In the present invention, the height of the cylindrical reactor is 100 to 150 cm, for example, 100 cm, 110 cm, 120 cm, 136 cm, 140 cm or 150 cm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0015] Preferably, the diameter of the cylindrical reactor is 60 to 80 cm, for example, 60 cm, 64 cm, 68 cm, 72 cm, 76 cm or 80 cm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0016] As a preferred technical solution of the present invention, the diameter difference between two adjacent overflow rings is 10 to 20 cm, for example, it can be 10 cm, 12 cm, 14 cm, 16 cm, 18 cm or 20 cm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0017] Preferably, the diameter of the overflow ring closest to the top of the cylindrical reactor is 30 to 60 cm larger than the diameter of the cylindrical reactor, for example, it can be 30 cm, 35 cm, 40 cm, 45 cm, 50 cm, 55 cm or 60 cm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0018] Preferably, the distance between the overflow ring closest to the top of the cylindrical reactor and the top of the cylindrical reactor is 10 to 20 cm, for example, it can be 10 cm, 12 cm, 14 cm, 16 cm, 18 cm or 20 cm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0019] Preferably, the height difference between two adjacent overflow rings is 20 to 50 cm, for example, 20 cm, 25 cm, 30 cm, 35 cm, 40 cm, 45 cm or 50 cm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0020] Preferably, an overflow weir is provided at one end of the overflow ring away from the cylindrical reactor.

[0021] Preferably, the height of the overflow weir is 2 to 3 cm, for example, 2 cm, 2.2 cm, 2.4 cm, 2.6 cm, 2.8 cm or 3 cm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0022] Preferably, the number of the overflow rings is 2 to 4, for example, 4, 3 or 4.

[0023] In the present invention, the height of the overflow weir is 2 to 3 cm. If the height is too high, the slurry obtained by overflowing from the top of the cylindrical reactor will not flow out easily. If the height is too low, it will not provide sufficient reaction time and effectively remove impurities in the slaked lime slurry.

[0024] As a preferred technical solution of the present invention, the distance between the overflow ring closest to the product collecting tank and the product collecting tank is 20 to 30 cm, for example, it can be 20 cm, 22 cm, 24 cm, 26 cm, 28 cm or 30 cm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0025] Preferably, the product collecting tank is seamlessly fixedly connected to the hollow base.

[0026] Preferably, the depth of the product collecting tank is 20 to 30 cm, for example, 20 cm, 22 cm, 24 cm, 26 cm, 28 cm or 30 cm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0027] Preferably, a product outlet groove is provided on the side of the product collecting groove.

[0028] In the present invention, the function of the product outlet tank is to outlet the calcium hydroxide slurry in the product collecting tank.

[0029] As a preferred technical solution of the present invention, a through hole is provided at the connection between the cylindrical reactor and the hollow base.

[0030] Preferably, the through hole is used to collect waste residue from the digestion reaction.

[0031] Preferably, a debris removal hole is provided at the bottom of the hollow base.

[0032] In the present invention, the hollow base and through holes are designed to collect lime slag and impurities, ensuring the easy maintenance of the reactor. During the digestion reaction, heavier slag and impurities will be deposited in the hollow area at the bottom, and then the lime slag and impurities will be regularly cleaned and removed through the impurity removal holes, ensuring the long-term and efficient operation of the reactor.

[0033] As a preferred technical solution of the present invention, a filtering device is provided at the bottom end of the cylindrical reactor.

[0034] Preferably, the filtering means comprises a screen.

[0035] In the present invention, according to the different particle sizes of quicklime used in the digestion reaction, a screen with a suitable aperture range is selected to reduce or avoid the loss of the reaction raw material quicklime during the digestion reaction.

[0036] Preferably, a stirring device is fixedly arranged inside the cylindrical reactor via a fixed bracket.

[0037] Preferably, the stirring device comprises a U-shaped stirring paddle or a spiral stirring paddle.

[0038] In the present invention, the stirring device is suitable for powerful stirring and uniform mixing of chemical reaction slurry, and can provide sufficient strength and stability during the stirring process to ensure uniform mixing of the slurry; in addition, the material of the stirring paddle includes stainless steel or other corrosion-resistant materials to adapt to high-intensity and long-term operation in the chemical reaction environment; the stirring device of the present invention helps to achieve uniform and efficient mixing of the slurry in the reactor, avoiding dead corners and uneven reactions.

[0039] As a preferred technical solution of the present invention, a water inlet hole is provided on the side of the cylindrical reactor.

[0040] Preferably, the distance between the water inlet hole and the hollow base is 3 to 5 cm, for example, 3 cm, 3.4 cm, 3.8 cm, 4.2 cm, 4.6 cm or 5 cm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0041] In the present invention, the quicklime digestion reaction is carried out in a cylindrical reactor, solid quicklime is fed at the top of the cylindrical reactor, and water is introduced through the water inlet at the lower end of the cylindrical reactor. Driven by the water flow, the upper part of the cylindrical reactor is filled with slaked lime slurry.

[0042] In a second aspect, the present invention provides a digestion method using the 7-bubbling quicklime digestion device provided in the first aspect, the digestion method comprising:

[0043] Water and quicklime are continuously added into the cylindrical reactor to carry out digestion reaction under stirring, and then after at least two levels of overflow, calcium hydroxide slurry is collected in a product collecting tank.

[0044] As a preferred technical solution of the present invention, the temperature of the water is 25-100°C, for example, it can be 25°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C or 100°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0045] Preferably, the mass ratio of quicklime to water is 1:4-6, for example, 1:4, 1:4.4, 1:4.8, 1:5.2, 1:5.6 or 1:6, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0046] In the present invention, the form of the quicklime is not limited, and it may be in powder form or in block form.

[0047] Preferably, the water is added through the water inlet, and the water addition rate is 6 to 30 kg / min, for example, 6 kg / min, 10 kg / min, 15 kg / min, 20 kg / min, 25 kg / min or 30 kg / min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0048] As a preferred technical solution of the present invention, the quicklime is added through the top of the cylindrical reactor.

[0049] Preferably, the addition rate of quicklime is 2 to 5 kg / min, for example, it can be 2 kg / min, 2.3 kg / min, 2.6 kg / min, 2.9 kg / min, 3.2 kg / min, 3.5 kg / min, 3.8 kg / min, 4.1 kg / min, 4.4 kg / min, 4.7 kg / min or 5 kg / min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0050] Preferably, the purity of the quicklime is ≥ 70%, for example, it can be 70%, 75%, 80%, 85%, 90% or 95%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0051] As a preferred technical solution of the present invention, the digestion reaction time is 40 to 70 minutes, for example, it can be 40 minutes, 45 minutes, 50 minutes, 55 minutes, 60 minutes, 65 minutes or 70 minutes, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0052] Preferably, the stirring speed is 5 to 20 r / min, for example, 5 r / min, 8 r / min, 11 r / min, 14 r / min, 17 r / min or 20 r / min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0053] As a preferred technical solution of the present invention, the digestion method further comprises: sequentially performing filter pressing treatment and drying treatment on the calcium hydroxide slurry;

[0054] Preferably, the drying temperature is 105-120°C, for example, 105°C, 108°C, 111°C, 114°C, 117°C or 120°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0055] Preferably, the drying time is 10 to 12 hours, for example, 10 hours, 10.4 hours, 10.8 hours, 11.2 hours, 11.6 hours or 12 hours, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0056] The numerical range described in the present invention not only includes the point values ​​listed above, but also includes any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0057] Compared with the prior art, the present invention has the following beneficial effects:

[0058] (1) The bubbling quicklime digestion device provided by the present invention realizes wet continuous digestion of quicklime through a cylindrical reactor and a multi-layer overflow ring design, and can effectively improve the utilization rate of the reactor, thereby improving the digestion efficiency and reducing energy consumption and pollution;

[0059] (2) The calcium hydroxide obtained by the digestion reaction using the bubbling quicklime digestion device provided by the present invention has a large specific surface area of ​​54 to 66 m 2 / g;

[0060] (3) The bubbling quicklime digestion device provided by the present invention has a simple structure, simple operation and a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 A schematic diagram of the structure of a bubbling quicklime digestion device provided in a specific embodiment of the present invention;

[0062] Figure 2 A cross-sectional view of a bubbling quicklime digestion device provided in a specific embodiment of the present invention;

[0063] Among them, 1 is a hollow base, 2 is a cylindrical reactor, 3 is a product collecting tank, 4 is an overflow ring, 5 is an overflow weir, 6 is a product outlet tank, and 7 is a water inlet. DETAILED DESCRIPTION

[0064] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0065] In one specific embodiment, the present invention provides a bubbling quicklime digestion device, such as Figure 1 and Figure 2 As shown, the device comprises a hollow base 1, and a cylindrical reactor 2 fixedly arranged at the center of the hollow base 1;

[0066] From the hollow base 1 upward, the side ring of the cylindrical reactor 2 is provided with a product collecting groove 3 and at least two overflow rings 4;

[0067] The diameter of the product collecting groove 3 is greater than the diameter of the adjacent overflow ring 4 , and the diameter of the overflow ring 4 decreases step by step along the direction of the product collecting groove 3 .

[0068] The diameter difference between two adjacent overflow rings 4 is 10 to 20 cm; the height difference between two adjacent overflow rings 4 is 20 to 50 cm; an overflow weir 5 is provided at one end of the overflow ring 4 away from the cylindrical reactor 2; the height of the overflow weir 5 is 2 to 3 cm; the diameter of the overflow ring 4 closest to the top of the cylindrical reactor 2 is 30 to 60 cm larger than the diameter of the cylindrical reactor 2; the distance between the overflow ring 4 closest to the top of the cylindrical reactor and the top of the cylindrical reactor 2 is 10 to 20 cm;

[0069] The product collecting tank 3 is seamlessly fixedly connected to the hollow base 1; the depth of the product collecting tank 3 is 20 to 30 cm; the distance between the overflow ring closest to the product collecting tank and the product collecting tank is 20 to 30 cm; a product outlet tank 6 is provided on the side of the product collecting tank 3;

[0070] A through hole is provided at the connection between the cylindrical reactor 2 and the hollow base 1; the through hole is used to collect waste residues from the digestion reaction; a removal hole is provided at the bottom of the hollow base 1;

[0071] A filtering device is provided at the bottom end of the cylindrical reactor 2; a stirring device is fixedly provided inside the cylindrical reactor 2 via a fixed bracket;

[0072] A water inlet 7 is provided on the side of the cylindrical reactor 2; the distance between the water inlet 7 and the hollow base 1 is 3-5 mm.

[0073] In a specific embodiment, the present invention provides a digestion method using the above-mentioned bubbling quicklime digestion device, the digestion method comprising:

[0074] Mix water at a temperature of 25 to 100° C. and quicklime with a purity of ≥70% in a mass ratio of 1:4 to 6 in a cylindrical reactor, perform a digestion reaction for 40 to 70 minutes under stirring at a speed of 5 to 20 r / min, and then collect calcium hydroxide slurry in a product collecting tank after at least two overflows; finally, perform filter pressing and drying on the calcium hydroxide slurry in turn;

[0075] Wherein, the quicklime is added through the top of the cylindrical reactor, and its adding rate is 2-5 kg / min; the water is added through the water inlet hole.

[0076] To better illustrate the present invention and facilitate understanding of the technical solution of the present invention, typical but non-limiting embodiments of the present invention are as follows:

[0077] Example 1

[0078] This embodiment provides a bubbling quicklime digestion device, such as Figure 1 and Figure 2 As shown, the device comprises a hollow base 1, and a cylindrical reactor 2 fixedly arranged at the center of the hollow base 1;

[0079] From the hollow base 1 upward, the side ring of the cylindrical reactor 2 is provided with a product collecting groove 3 and at least two overflow rings 4;

[0080] The diameter of the product collecting groove 3 is greater than the diameter of the adjacent overflow ring 4 , and the diameter of the overflow ring 4 decreases step by step along the direction of the product collecting groove 3 .

[0081] The diameter difference between two adjacent overflow rings 4 is 20 cm; the height difference between two adjacent overflow rings 4 is 50 cm; an overflow weir 5 is provided at one end of the overflow ring 4 away from the cylindrical reactor 2; the height of the overflow weir 5 is 2.5 m; the diameter of the overflow ring closest to the top of the cylindrical reactor is 60 cm larger than the diameter of the cylindrical reactor; the distance between the overflow ring closest to the top of the cylindrical reactor and the top of the cylindrical reactor is 20 cm;

[0082] The product collecting tank 3 is seamlessly fixedly connected to the hollow base 1; the depth of the product collecting tank 3 is 25 cm; the distance between the overflow ring closest to the product collecting tank and the product collecting tank is 25 cm; a product outlet tank 6 is provided on the side of the product collecting tank 3;

[0083] A through hole is provided at the connection between the cylindrical reactor 2 and the hollow base 1; the through hole is used to collect waste residues from the digestion reaction; a removal hole is provided at the bottom of the hollow base 1;

[0084] A filtering device is provided at the bottom end of the cylindrical reactor 2; a stirring device is fixedly provided inside the cylindrical reactor 2 via a fixed bracket;

[0085] A water inlet 7 is provided on the side of the cylindrical reactor 2; the distance between the water inlet 7 and the hollow base 1 is 4 mm.

[0086] Example 2

[0087] This embodiment provides a bubbling quicklime digestion device, which includes a hollow base 1 and a cylindrical reactor 2 fixedly arranged at the center of the hollow base 1;

[0088] From the hollow base 1 upward, the side ring of the cylindrical reactor 2 is provided with a product collecting groove 3 and at least two overflow rings 4;

[0089] The diameter of the product collecting groove 3 is greater than the diameter of the adjacent overflow ring 4 , and the diameter of the overflow ring 4 decreases step by step along the direction of the product collecting groove 3 .

[0090] The diameter difference between two adjacent overflow rings 4 is 15 cm; the height difference between two adjacent overflow rings 4 is 40 cm; an overflow weir 5 is provided at one end of the overflow ring 4 away from the cylindrical reactor 2; the height of the overflow weir 5 is 3 cm; the diameter of the overflow ring closest to the top of the cylindrical reactor is 50 cm larger than the diameter of the cylindrical reactor; the distance between the overflow ring closest to the top of the cylindrical reactor and the top of the cylindrical reactor is 15 cm;

[0091] The product collecting tank 3 is seamlessly fixedly connected to the hollow base 1; the depth of the product collecting tank 3 is 30 cm; the distance between the overflow ring closest to the product collecting tank and the product collecting tank is 20 cm; a product outlet tank 6 is provided on the side of the product collecting tank 3;

[0092] A through hole is provided at the connection between the cylindrical reactor 2 and the hollow base 1; the through hole is used to collect waste residues from the digestion reaction; a removal hole is provided at the bottom of the hollow base 1;

[0093] A filtering device is provided at the bottom end of the cylindrical reactor 2; a stirring device is fixedly provided inside the cylindrical reactor 2 via a fixed bracket;

[0094] A water inlet 7 is provided on the side of the cylindrical reactor 2; the distance between the water inlet 7 and the hollow base 1 is 5 mm.

[0095] Example 3

[0096] This embodiment provides a bubbling quicklime digestion device, which includes a hollow base 1 and a cylindrical reactor 2 fixedly arranged at the center of the hollow base 1;

[0097] From the hollow base 1 upward, the side ring of the cylindrical reactor 2 is provided with a product collecting groove 3 and at least two overflow rings 4;

[0098] The diameter of the product collecting groove 3 is greater than the diameter of the adjacent overflow ring 4 , and the diameter of the overflow ring 4 decreases step by step along the direction of the product collecting groove 3 .

[0099] The diameter difference between two adjacent overflow rings 4 is 17 cm; the height difference between two adjacent overflow rings 4 is 20 cm; an overflow weir 5 is provided at one end of the overflow ring 4 away from the cylindrical reactor 2; the height of the overflow weir 5 is 2 cm; the diameter of the overflow ring closest to the top of the cylindrical reactor is 40 cm larger than the diameter of the cylindrical reactor; the distance between the overflow ring closest to the top of the cylindrical reactor and the top of the cylindrical reactor is 10 cm;

[0100] The product collecting tank 3 is seamlessly fixedly connected to the hollow base 1; the depth of the product collecting tank 3 is 20 cm; the distance between the overflow ring closest to the product collecting tank and the product collecting tank is 30 cm; a product outlet tank 6 is provided on the side of the product collecting tank 3;

[0101] A through hole is provided at the connection between the cylindrical reactor 2 and the hollow base 1; the through hole is used to collect waste residues from the digestion reaction; a removal hole is provided at the bottom of the hollow base 1;

[0102] A filtering device is provided at the bottom end of the cylindrical reactor 2; a stirring device is fixedly provided inside the cylindrical reactor 2 via a fixed bracket;

[0103] A water inlet 7 is provided on the side of the cylindrical reactor 2; the distance between the water inlet 7 and the hollow base 1 is 3 mm.

[0104] Example 4

[0105] This embodiment provides a bubbling quicklime digestion device, which differs from the embodiment 1 only in that:

[0106] In this embodiment, the height difference between two adjacent overflow rings 4 is adjusted to 10 cm.

[0107] Example 5

[0108] This embodiment provides a bubbling quicklime digestion device, which differs from the embodiment 1 only in that:

[0109] In this embodiment, the height of the overflow weir 5 is adjusted to 0.5 cm.

[0110] Example 6

[0111] This embodiment provides a bubbling quicklime digestion device, which differs from the embodiment 1 only in that:

[0112] In this embodiment, the height of the overflow weir 5 is adjusted to 4 cm.

[0113] Example 7

[0114] This embodiment provides a bubbling quicklime digestion device, which differs from the embodiment 1 only in that:

[0115] In this embodiment, the distance between the water inlet hole 7 and the hollow base 1 is adjusted to 10 cm.

[0116] Example 8

[0117] This embodiment provides a bubbling quicklime digestion device, which differs from the embodiment 1 only in that:

[0118] In this embodiment, the stirring device disposed inside the cylindrical reactor 2 is omitted.

[0119] Comparative Example 1

[0120] This comparative example provides a bubbling quicklime digestion device, which differs from Example 1 only in that:

[0121] In this comparative example, the overflow ring 4 arranged around the side of the cylindrical reactor 2 is omitted.

[0122] Comparative Example 2

[0123] This comparative example provides a bubbling quicklime digestion device, which differs from Example 1 only in that:

[0124] In this comparative example, the diameter difference between two adjacent overflow rings 4 is adjusted to 0 cm.

[0125] Comparative Example 3

[0126] This comparative example provides a bubbling quicklime digestion device, which differs from Example 1 only in that:

[0127] In this comparative example, the hollow base is adjusted to a solid base.

[0128] Application Example 1

[0129] This application example provides a digestion method using the bubbling quicklime digestion device provided in Example 1, and the digestion method comprises:

[0130] Mix water at a temperature of 65° C. and quicklime with a purity of 80% in a mass ratio of 1:5 in a cylindrical reactor, perform a digestion reaction for 55 minutes under a stirring state at a speed of 13 r / min, and then collect calcium hydroxide slurry in a product collecting tank after two-stage overflow;

[0131] Wherein, the quicklime is added through the top of the cylindrical reactor, and its adding rate is 3.5 kg / min; the water is added through the water inlet.

[0132] Application Example 2

[0133] This application example provides a digestion method using the bubbling quicklime digestion device provided in Example 2, the digestion method comprising:

[0134] Mix water at a temperature of 25° C. and quicklime with a purity of 70% in a mass ratio of 1:4 in a cylindrical reactor, perform a digestion reaction for 70 minutes under a stirring state at a speed of 5 r / min, and then collect calcium hydroxide slurry in a product collecting tank after three-stage overflow;

[0135] Wherein, the quicklime is added through the top of the cylindrical reactor, and its adding rate is 2kg / min; the water is added through the water inlet.

[0136] Application Example 3

[0137] This application example provides a digestion method using the bubbling quicklime digestion device provided in Example 3, and the digestion method comprises:

[0138] Mix water at a temperature of 100° C. and quicklime with a purity of 85% in a mass ratio of 1:6 in a cylindrical reactor, perform a digestion reaction for 40 minutes under a stirring state at a speed of 20 r / min, and then collect calcium hydroxide slurry in a product collecting tank after four-stage overflow;

[0139] Wherein, the quicklime is added through the top of the cylindrical reactor, and its adding rate is 5kg / min; the water is added through the water inlet.

[0140] Application Example 4

[0141] This application example provides a digestion method using the bubbling quicklime digestion device provided in Example 4, and the digestion method is the same as that in Application Example 1.

[0142] Application Example 5

[0143] This application example provides a digestion method using the bubbling quicklime digestion device provided in Example 5, and the digestion method is the same as that in Application Example 1.

[0144] Application Example 6

[0145] This application example provides a digestion method using the bubbling quicklime digestion device provided in Example 6, and the digestion method is the same as that in Application Example 1.

[0146] Application Example 7

[0147] This application example provides a digestion method using the bubbling quicklime digestion device provided in Example 7, and the digestion method is the same as that in Application Example 1.

[0148] Application Example 8

[0149] This application example provides a digestion method using the bubbling quicklime digestion device provided in Example 8, and the digestion method is the same as that of Application Example 1.

[0150] Application Example 9

[0151] This application example provides a digestion method using the bubbling quicklime digestion device provided in Example 1. The digestion method is different from that in Application Example 1 only in that:

[0152] In this application example, the mass ratio of water to quicklime is adjusted to 1:2.

[0153] Application Example 10

[0154] This application example provides a digestion method using the bubbling quicklime digestion device provided in Example 1. The digestion method is different from that in Application Example 1 only in that:

[0155] In this application example, the mass ratio of water to quicklime is adjusted to 1:8.

[0156] Comparative application example 1

[0157] This comparative application example provides a digestion method using the bubbling quicklime digestion device provided in Comparative Example 1, and the digestion method is the same as that of Application Example 1.

[0158] Comparative Application Example 2

[0159] This comparative application example provides a digestion method using the bubbling quicklime digestion device provided in Comparative Example 2, and the digestion method is the same as that of Application Example 1.

[0160] Comparative Application Example 3

[0161] This comparative application example provides a digestion method using the bubbling quicklime digestion device provided in Comparative Example 3, and the digestion method is the same as that of Application Example 1.

[0162] Performance testing:

[0163] The calcium hydroxide slurry provided in the above application examples and comparative application examples was subjected to filter pressing treatment and drying treatment at 110° C. for 12 hours to obtain calcium hydroxide solid, and the obtained calcium hydroxide solid was subjected to specific surface area test, pore volume test and purity test, and the results are shown in Table 1. ;

[0164] Table 1

[0165] <![CDATA[Specific surface area (m 2 / g)]]> Pore ​​volume (cc / g) Purity (wt%) Application Example 1 54.4429 0.221635 90.5 Application Example 2 60.5651 0.280474 89.3 Application Example 3 65.329 0.316101 89.1 Application Example 4 56.1909 0.233431 90.3 Application Example 5 53.2043 0.232827 84.7 Application Example 6 43.0335 0.190226 91.2 Application Example 7 51.4947 0.215323 89.6 Application Example 8 59.4617 0.261425 80.3 Application Example 9 41.0132 0.14785 89.5 Application Example 10 52.7941 0.208678 90.1 Comparative application example 1 45.7295 0.199898 83.3 Comparative Application Example 2 53.0611 0.224946 88.4 Comparative Application Example 3 40.9501 0.186343 88.8

[0166] According to Table 1, we can know the following points:

[0167] (1) Comprehensive analysis of application examples 1-3 shows that the calcium hydroxide obtained by the digestion reaction using the device provided by the present invention has a higher specific surface area and purity;

[0168] (2) Comprehensive analysis of Application Example 1 and Application Examples 4-6 shows that the arrangement of the overflow ring will affect the reaction efficiency. When the height difference between two adjacent overflow rings is low (such as in Application Example 4), it will result in failure to provide sufficient reaction time and effectively remove impurities in the slaked lime slurry.

[0169] When the overflow weir height of the overflow ring is too high (such as application example 6), it will make it difficult for the slurry to flow out;

[0170] When the overflow weir height of the overflow ring is too low (such as in Application Example 5), it will result in failure to provide sufficient reaction time and effectively remove impurities in the slaked lime slurry;

[0171] (4) Comprehensive analysis of Application Examples 1 and 8 shows that when no stirring is performed during the digestion reaction, the reaction will be incomplete;

[0172] (5) Comprehensive analysis of Application Example 1 and Comparative Application Examples 1-2 shows that the presence of the overflow ring can prolong the residence time of the reactants during the digestion reaction, making the reaction more thorough; when the overflow ring is omitted (such as Comparative Example 1), the impurity content in the collected product slurry will increase;

[0173] When the overflow rings are not distributed in a stepped manner, only a single-layer overflow effect will be achieved, and the purity and specific surface area of ​​the obtained calcium hydroxide will be reduced.

[0174] In summary, the present invention performs limestone digestion by bubbling, can realize continuous digestion, obtain calcium hydroxide with a high specific surface area, thereby improving digestion efficiency, reducing energy consumption and pollution, and is easy to operate, has high production efficiency, and has efficient mixing ability, thereby solving the problems existing in the prior art that block quicklime is buried in slaked lime powder, resulting in the doping of unreacted particulate impurities in the finished product, and the like.

[0175] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention are within the protection scope and disclosure scope of the present invention.

Claims

1. A bubbling quicklime digestion device, characterized in that: The device comprises a hollow base and a cylindrical reactor fixedly arranged at the center of the hollow base; In the direction upward from the hollow base, the side ring of the cylindrical reactor is provided with a product collecting groove and at least two overflow rings; The diameter of the product collecting groove is greater than the diameter of the adjacent overflow ring, and the diameter of the overflow ring decreases step by step along the direction of the product collecting groove.

2. The bubbling quicklime digestion device according to claim 1, characterized in that: The diameter difference between two adjacent overflow rings is 10 to 20 cm; Preferably, the height difference between two adjacent overflow rings is 20 to 50 cm; Preferably, an overflow weir is provided at one end of the overflow ring away from the cylindrical reactor; Preferably, the height of the overflow weir is 2 to 3 cm; Preferably, the number of the overflow rings is 2 to 4.

3. The bubbling quicklime digestion device according to claim 1 or 2, characterized in that: The product collecting tank is seamlessly and fixedly connected to the hollow base; Preferably, the depth of the product collection tank is 20 to 30 cm; Preferably, a product outlet groove is provided on the side of the product collecting groove.

4. The bubbling quicklime digestion device according to any one of claims 1 to 3, characterized in that: A through hole is provided at the connection between the cylindrical reactor and the hollow base; Preferably, the through hole is used to collect waste residue from the digestion reaction; Preferably, a debris removal hole is provided at the bottom of the hollow base.

5. The bubbling quicklime digestion device according to any one of claims 1 to 4, characterized in that: A filtering device is provided at the bottom end of the cylindrical reactor; Preferably, the filtering device comprises a screen; Preferably, a stirring device is fixedly arranged inside the cylindrical reactor via a fixed bracket; Preferably, the stirring device comprises a U-shaped stirring paddle or a spiral stirring paddle.

6. The bubbling quicklime digestion device according to any one of claims 1 to 5, characterized in that: A water inlet hole is provided on the side of the cylindrical reactor; Preferably, the distance between the water inlet hole and the hollow base is 3 to 5 mm.

7. A digestion method using the bubbling quicklime digestion device according to any one of claims 1 to 6, characterized in that: The digestion method comprises: Water and quicklime are continuously added into the cylindrical reactor to carry out digestion reaction under stirring, and then after at least two levels of overflow, calcium hydroxide slurry is collected in a product collecting tank.

8. The digestion method according to claim 7, characterized in that: The temperature of the water is 25-100°C; Preferably, the mass ratio of water to quicklime is 1:4-6; Preferably, the water is added through a water inlet, and the water addition rate is 6-30 kg / min; Preferably, the quicklime is added through the top of the cylindrical reactor; Preferably, the addition rate of quicklime is 2-5 kg / min; Preferably, the purity of the quicklime is ≥70%.

9. The digestion method according to claim 7 or 8, characterized in that: The digestion reaction time is 40 to 70 minutes; Preferably, the stirring speed is 5 to 20 r / min.

10. The digestion method according to any one of claims 7 to 9, characterized in that: The digestion method further comprises: sequentially performing filter pressing and drying on the calcium hydroxide slurry; Preferably, the drying temperature is 105-120°C; Preferably, the drying time is 10 to 12 hours.

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