Device and method for preparing potassium sulfite

Abstract

The device comprises a potassium sulfite reaction kettle and a sulfur dioxide buffer tank, a reaction kettle jacket is arranged outside the potassium sulfite reaction kettle, the reaction kettle jacket is connected with a circulating water pipeline, a discharging opening in the bottom of the reaction kettle is connected to a potassium sulfite circulating pump, and the sulfur dioxide buffer tank is connected with a sulfur dioxide circulating pump. An outlet of the potassium sulfite circulating pump is connected to an ejector, a discharge port of the ejector extends into the potassium sulfite reaction kettle and is connected with a telescopic guide pipe, an outlet of the sulfur dioxide buffer tank is connected to a side port of the ejector, and a distribution mechanism is arranged in the potassium sulfite reaction kettle. An existing potassium hydroxide product and sulfur dioxide produced by a company react to generate the potassium sulfite solution, the production cost is low, the reaction process is simple, operation is convenient, the production cost is greatly reduced, an aqueous solution is directly generated and conveyed to saline water for treatment and use through a pipeline, and the manual burdening step is omitted.

Description

Technical Field

[0001] The invention relates to the technical field of preparing refined agents in the ion membrane alkali production industry, and in particular to a device and method for preparing potassium sulfite. Background Art

[0002] Potassium sulfite is a widely used chemical raw material. In the photographic industry, it is used as a reducing agent for developer. In the food industry, it is used as a bleaching agent, preservative, and antioxidant to preserve fresh fruits, vegetables, and meat. In the printing and dyeing industry, it is used as a reducing agent for dyes. It can also be used as a bleaching agent in the processing of wool and silk and in pulp and papermaking. In this ion membrane alkali production process, it is mainly used to control free chlorine in brine.

[0003] At present, there are two main methods for producing potassium sulfite: potassium carbonate method and potassium hydroxide method. The process of producing potassium sulfite by potassium carbonate method is to pass sulfur dioxide into potassium carbonate solution for reaction, add an equal amount of potassium carbonate after the solution is saturated, and then evaporate and crystallize to obtain it. Its main reaction formula is: SO2+K2CO3=K2SO3+CO2. The purity of potassium sulfite prepared by this method is poor. Potassium hydroxide method is to produce potassium sulfite by reacting potassium hydroxide with sulfur dioxide. Its main reaction formula is 2KOH+SO2=K2SO3+H2O, and this method can produce relatively pure potassium sulfite.

[0004] At present, during the treatment of ion membrane alkali brine, chlorine-containing brine is added to decompose organic carbon, and the excess free chlorine in the brine needs to be neutralized by adding potassium sulfite. Currently, industrial potassium sulfite is a niche product on the market, with a small output, difficult to purchase, and relatively expensive. Purchasing solid potassium sulfite will greatly increase the cost of the ion membrane alkali brine treatment process. Our company currently has a sulfuric acid device that produces excess sulfur dioxide gas. Using the product potassium hydroxide and sulfur dioxide to produce potassium sulfite solution for self-use will greatly save production costs. Therefore, it is urgent to develop a process device and method for preparing potassium sulfite. Summary of the invention

[0005] In order to solve the problems mentioned in the above background technology, the present invention provides a device and method for preparing potassium sulfite.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A device for preparing potassium sulfite comprises a potassium sulfite reactor and a sulfur dioxide buffer tank, wherein a reactor jacket is arranged outside the potassium sulfite reactor, the reactor jacket is connected with a circulating water pipeline, a discharge port at the bottom of the reactor is connected to a potassium sulfite circulating pump, an outlet of the potassium sulfite circulating pump is connected to an ejector, a discharge port of the ejector extends to the interior of the potassium sulfite reactor and is connected with a telescopic conduit, an outlet of the sulfur dioxide buffer tank is connected to a side port of the ejector, a distribution mechanism is arranged inside the potassium sulfite reactor, the bottom end of the telescopic conduit is communicated with the distribution mechanism, a cylinder is installed at the top end of the potassium sulfite reactor, an output shaft of the cylinder extends to the interior of the potassium sulfite reactor and is connected with the distribution mechanism.

[0008] Preferably, the distribution mechanism includes an annular lifting tube, the top end of the annular lifting tube is fixed to the output end of the cylinder, the bottom end of the telescopic guide tube is connected to the interior of the annular lifting tube, the inner ring of the annular lifting tube is provided with an annular mounting port, a first annular baffle is rotatably mounted inside the annular mounting port, and a plurality of liquid guiding curved pipes are mounted on the first annular baffle.

[0009] Preferably, a second annular baffle is fixed inside the annular lifting tube, the first annular baffle and the second annular baffle are in close contact, and corresponding through holes are provided on the first annular baffle and the second annular baffle. When the through holes on the first annular baffle and the second annular baffle are aligned, the gas inside the annular lifting tube can enter the liquid guiding elbow unimpeded.

[0010] Preferably, the bottom end of the liquid guiding curved tube is fixed to a circular ring bracket via a first connecting rod, and the circular ring bracket is rotatably connected to the bottom end of the annular lifting tube.

[0011] Preferably, an annular guide rail is fixed to the bottom end of the annular lifting tube, a second bracket is fixed to the bottom end of the annular bracket, a slider is fixed to one end of the second bracket away from the annular bracket, and the slider is slidably mounted on the annular guide rail.

[0012] Preferably, a vertically arranged cylinder is fixed inside the potassium sulfite reactor, a spiral guide groove is provided on the outside of the cylinder, the cylinder passes through a circular ring bracket, a spiral guide groove is provided on the outside of the cylinder, a horizontally arranged guide rod is fixed on the inner wall of the circular ring bracket, and one end of the guide rod extends into the spiral guide groove.

[0013] Preferably, the top end of the liquid guiding elbow is connected to a vertical conduit, and a nozzle is fixed to the top end of the vertical conduit.

[0014] Preferably, a stirring branch is installed outside the vertical conduit, and the heights of the vertical conduits are different.

[0015] Preferably, the device further comprises a pressure gauge, a thermometer, a regulating valve, and a flow meter, and a pH online detection device is provided on the outlet circulation pipeline of the potassium sulfite circulation pump.

[0016] A method for preparing potassium sulfite comprises the following steps:

[0017] S1: The potassium hydroxide delivery pump delivers potassium hydroxide into the potassium sulfite reactor, and a quantitative potassium hydroxide solution is added at one time through the liquid level meter;

[0018] S2: The potassium hydroxide is circulated in the ejector through the potassium sulfite circulation pump, and the jacket of the reactor is connected to the circulating water and opened to control the reaction temperature;

[0019] S3: Control the sulfur dioxide to flow into the ejector through the conditional valve, and the sulfur dioxide and sodium hydroxide are fully mixed and reacted to generate potassium sulfite. The amount of sulfur dioxide added is controlled according to the pressure and temperature of the potassium sulfite reactor;

[0020] S4: PH online detection: When the PH of potassium sulfite in the potassium sulfite reactor is close to neutral, the sulfur dioxide is turned off and the potassium sulfite solution is sent to the potassium sulfite temporary storage tank through the outlet branch line of the potassium sulfite circulation pump.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The present invention utilizes existing raw materials, sulfur dioxide and potassium hydroxide, to react and generate potassium sulfite. Compared with purchasing potassium sulfite from outside, the cost is greatly reduced. The aqueous solution is directly generated and transported to the brine for treatment through a pipeline, thus saving the manual batching step.

[0023] 2. During the reaction of sulfur dioxide and potassium hydroxide, a jet pump is used to fully mix the gas and liquid to increase the reaction rate, allowing the introduced sulfur dioxide to react completely and preventing the generation of sulfur dioxide tail gas; the reactor jacket is equipped with circulating water for cooling, and the circulating water is used to remove the heat generated by the reaction to promote the reaction. A pH meter is installed on the reactor circulation line to keep the reaction at a weak alkaline state, which can effectively prevent the generation of potassium bisulfite due to excessive sulfur dioxide.

[0024] 3. There is no wastewater or waste residue discharge, and the discharge of the three wastes meets environmental protection requirements; it not only improves economic benefits, but also improves environmental benefits.

[0025] 4. The design of the annular lifting pipe, the first annular baffle, the second annular baffle, the liquid guiding elbow, the annular bracket and other components in the distribution mechanism enables the nozzle to spray liquid intermittently, forming a local high concentration area in the kettle, and promoting more uniform mixing between the liquids.

[0026] 5. The circular bracket can rotate relative to the annular lifting tube, driving the stirring branch to stir the material and accelerate the reaction. At the same time, the heights of the vertical conduits are not equal, making the dispersion of the incoming liquid higher;

[0027] 6. The spiral guide groove on the cylinder cooperates with the guide rod on the inner wall of the circular ring bracket, and drives the circular ring bracket to rotate when the annular lifting tube moves, thereby realizing the automatic stirring and liquid dispersing functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 is a process flow chart of the present invention;

[0030] Figure 2 This is a front view of a potassium sulfite reactor of the present invention;

[0031] Figure 3 This is a cross-sectional view of the potassium sulfite reactor of the present invention from the main perspective;

[0032] Figure 4 It is a sectional view of a potassium sulfite reactor of the present invention from a three-dimensional perspective;

[0033] Figure 5 for Figure 3 A zoomed-in detail of position A in the middle;

[0034] Figure 6 This is an enlarged detail view of the distribution mechanism of the present invention from the first perspective;

[0035] Figure 7 This is an enlarged detail view of the distribution mechanism of the present invention from a second viewing angle;

[0036] Figure 8 This is an enlarged detail view of the distribution mechanism of the present invention from a third viewing angle;

[0037] Fig. 9 It is a schematic diagram of the matching relationship between the circular ring bracket and the cylinder of the present invention;

[0038] Fig.10 This is an enlarged detail view of the location of the liquid guide elbow of the present invention;

[0039] In the figure: 1 potassium sulfite reactor, 101 potassium sulfite reactor, 102 ejector, 1021 ejector side port, 103 telescopic guide tube, 2 annular lift tube, 201 second annular baffle, 202 annular guide rail, 3 first annular baffle, 301 liquid guide elbow, 302 vertical guide tube, 303 nozzle, 304 nozzle, 4 annular bracket, 401 first connecting rod, 402 second bracket, 403 guide rod, 5 cylinder, 501 spiral guide groove, 6 cylinder. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] Example 1

[0042] Reference Figure 2-10 , a device for preparing potassium sulfite, comprising a potassium sulfite reactor 1 and a sulfur dioxide buffer tank, a reactor jacket 101 is provided on the outside of the potassium sulfite reactor 1, a circulating water pipeline is connected to the reactor jacket 101, a discharge port at the bottom of the reactor is connected to a potassium sulfite circulation pump, an outlet of the potassium sulfite circulation pump is connected to an ejector 102, an ejector 102 discharge port extends to the interior of the potassium sulfite reactor 1 and is connected to a telescopic conduit 103, an outlet of the sulfur dioxide buffer tank is connected to a side port 1021 of the ejector, a distribution mechanism is provided inside the potassium sulfite reactor 1, a bottom end of the telescopic conduit 103 is connected to the distribution mechanism, a cylinder 6 is installed on the top of the potassium sulfite reactor 1, an output shaft of the cylinder 6 extends to the interior of the potassium sulfite reactor 1 and is connected to the distribution mechanism;

[0043] The potassium hydroxide is driven to circulate in the ejector 102 by the power of the potassium sulfite circulation pump, and the sulfur dioxide is drawn into the liquid by the power of the liquid circulation and brought into the potassium sulfite reactor 1. The mixing effect is improved through circulation, and the reaction rate is increased. The distribution mechanism can improve the dispersion uniformity of the return liquid and further improve the mixing effect.

[0044] The distribution mechanism includes an annular lifting pipe 2, the top of which is fixed to the output end of the cylinder 6, the bottom of the telescopic guide tube 103 is connected to the inside of the annular lifting pipe 2, the inner ring of the annular lifting pipe 2 is provided with an annular mounting opening, a first annular baffle 3 is rotatably mounted inside the annular mounting opening, and a plurality of liquid guiding curved pipes 301 are mounted on the first annular baffle 3;

[0045] The cylinder 6 can drive the annular lifting tube 2 to move up and down, thereby driving the liquid guiding curved tube 301 to move up and down. The top of the liquid guiding curved tube 301 is connected to a vertical conduit 302, and a nozzle 303 is fixed to the top of the vertical conduit 302. By continuously driving the nozzle 303 to move up and down, the mixing effect can be further improved.

[0046] Among them, a second annular baffle 201 is fixed inside the annular lifting tube 2, the first annular baffle 3 and the second annular baffle 201 are in close contact, and corresponding through holes are opened on the first annular baffle 3 and the second annular baffle 201. When the through holes on the first annular baffle 3 and the second annular baffle 201 are aligned, the gas inside the annular lifting tube 2 can enter the liquid guiding curved tube 301 without hindrance.

[0047] The bottom end of the liquid guiding curved tube 301 is fixed to a circular bracket 4 through a first connecting rod 401, the circular bracket 4 is rotatably connected to the bottom end of the circular lifting tube 2, a circular guide rail 202 is fixed to the bottom end of the circular lifting tube 2, a second bracket 402 is fixed to the bottom end of the circular bracket 4, a slider is fixed to one end of the second bracket 402 away from the circular bracket 4, and the slider is slidably mounted on the circular guide rail 202;

[0048] A plurality of liquid guiding curved pipes 301 are fixed together by a circular ring bracket 4, and are rotatably mounted on the circular lifting tube 2 by a second bracket 402. The circular ring bracket 4 can rotate relative to the circular lifting tube 2. When the circular ring bracket 4 rotates, the first circular baffle 3 and the second circular baffle 201 can rotate relatively continuously, so that the through holes on the first circular baffle 3 and the second circular baffle 201 are intermittently aligned, so that the nozzle 303 intermittently sprays liquid, forming local high-concentration areas in the reactor. These high-concentration areas will cause a strong concentration gradient to be generated between the liquid and the existing material in the reactor. According to Fick's law, the diffusion rate of a substance is proportional to the concentration gradient. This larger concentration gradient can accelerate the diffusion process of the substance, thereby making the mixing between the liquids more uniform.

[0049] Among them, a vertically arranged cylinder 5 is fixed inside the potassium sulfite reactor 1, a spiral guide groove 501 is opened on the outer side of the cylinder 5, the cylinder 5 passes through the circular ring bracket 4, a spiral guide groove 501 is opened on the outer side of the cylinder 5, and a horizontally arranged guide rod 403 is fixed on the inner wall of the circular ring bracket 4, and one end of the guide rod 403 extends into the spiral guide groove 501;

[0050] When the annular lifting tube 2 moves, the annular bracket 4 moves up and down along the cylinder 5. Since one end of the guide rod 403 extends into the spiral guide groove 501, the annular bracket 4 can be driven to rotate relative to the annular lifting tube 2. A stirring branch 304 is installed on the outside of the vertical conduit 302. When the annular bracket 4 rotates, it can drive the stirring branch 304 to stir the material and accelerate the reaction.

[0051] Wherein, a stirring branch 304 is installed outside the vertical conduit 302, and the heights of the vertical conduits 302 are not equal;

[0052] This allows the multiple nozzles 303 to be more widely distributed in horizontal height, further improving the dispersion of the incoming liquid.

[0053] The device also includes a pressure gauge, a thermometer, a regulating valve, a flow meter, and a PH online detection is arranged on the outlet circulation pipeline of the potassium sulfite circulation pump.

[0054] Reference Figure 1 , a method for preparing potassium sulfite, comprising the following steps:

[0055] S1: The potassium hydroxide delivery pump delivers potassium hydroxide into the potassium sulfite reactor 1, and a quantitative potassium hydroxide solution is added at one time through the liquid level meter;

[0056] S2: The potassium hydroxide is circulated in the ejector 102 through the potassium sulfite circulation pump, and the jacket of the reactor 101 is connected to the circulating water and opened to control the reaction temperature;

[0057] S3: Control the sulfur dioxide to be introduced into the ejector 102 through the conditional valve, and the sulfur dioxide and sodium hydroxide are fully mixed and reacted to generate potassium sulfite. The amount of sulfur dioxide added is controlled according to the pressure and temperature of the potassium sulfite reactor 1, and the reaction temperature can be controlled below 40°C;

[0058] S4: PH online detection: When the PH of potassium sulfite in potassium sulfite reactor 1 is close to neutral, sulfur dioxide is turned off, and the potassium sulfite solution is sent to the potassium sulfite temporary storage tank through the outlet branch line of the potassium sulfite circulation pump.

[0059] After three months of continuous and stable operation, the potassium sulfite solution was prepared by this device, and the reaction temperature could be effectively controlled below 40°C. The pH value and sulfur dioxide regulating valve were interlocked, and the reaction endpoint was controlled relatively smoothly. The potassium sulfite content produced was stable at about 30%, and the residual potassium hydroxide content was less, indicating that the reaction was relatively thorough, and the total potassium bisulfite content of the solution was within the index range; the potassium sulfite solution with good reaction could be directly transported to the brine section through a pipeline for use, saving the original step of feeding solid materials; at the same time, the operation was simple, and most of the entire device was automatically controlled. The implementation of this invention has created great production benefits, reduced the production cost of ion membrane alkali production in disguise, improved the production level, and enhanced the company's product competitiveness.

[0060] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0061] In the present invention, unless otherwise clearly specified and limited, the terms "set", "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0062] The control method of the present invention is automatic control through a controller. The control circuit of the controller can be implemented by simple programming by technicians in this field. The provision of power is also common knowledge in this field. The present invention is mainly used to protect mechanical devices, so the present invention will no longer explain the control method and circuit connection in detail.

[0063] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A device for preparing potassium sulfite, comprising a potassium sulfite reactor (1) and a sulfur dioxide buffer tank, characterized in that: The potassium sulfite reactor (1) is provided with a reactor jacket (101) on the outside, the reactor jacket (101) is connected to a circulating water pipeline, the discharge port at the bottom of the reactor is connected to a potassium sulfite circulating pump, the outlet of the potassium sulfite circulating pump is connected to an ejector (102), the discharge port of the ejector (102) extends to the inside of the potassium sulfite reactor (1) and is connected to a telescopic conduit (103), the outlet of the sulfur dioxide buffer tank is connected to a side port (1021) of the ejector, a distribution mechanism is provided inside the potassium sulfite reactor (1), the bottom end of the telescopic conduit (103) is connected to the distribution mechanism, a cylinder (6) is installed at the top end of the potassium sulfite reactor (1), the output shaft of the cylinder (6) extends to the inside of the potassium sulfite reactor (1) and is connected to the distribution mechanism.

2. A device for preparing potassium sulfite according to claim 1, characterized in that: The distribution mechanism comprises an annular lifting pipe (2), the top end of the annular lifting pipe (2) is fixed to the output end of the cylinder (6), the bottom end of the telescopic guide tube (103) is connected to the inside of the annular lifting pipe (2), the inner ring of the annular lifting pipe (2) is provided with an annular mounting opening, a first annular baffle (3) is rotatably mounted inside the annular mounting opening, and a plurality of liquid guiding curved pipes (301) are mounted on the first annular baffle (3).

3. A device for preparing potassium sulfite according to claim 1, characterized in that: A second annular baffle (201) is fixed inside the annular lifting tube (2); the first annular baffle (3) and the second annular baffle (201) are in close contact; corresponding through holes are provided on the first annular baffle (3) and the second annular baffle (201); when the through holes on the first annular baffle (3) and the second annular baffle (201) are aligned, gas inside the annular lifting tube (2) can enter the liquid guiding curved tube (301) without hindrance.

4. A device for preparing potassium sulfite according to claim 3, characterized in that: The bottom end of the liquid guiding curved tube (301) is fixed to a circular ring bracket (4) via a first connecting rod (401), and the circular ring bracket (4) is rotatably connected to the bottom end of the annular lifting tube (2).

5. A device for preparing potassium sulfite according to claim 4, characterized in that: A circular guide rail (202) is fixed to the bottom end of the circular lifting tube (2), a second bracket (402) is fixed to the bottom end of the circular bracket (4), a slider is fixed to the end of the second bracket (402) away from the circular bracket (4), and the slider is slidably mounted on the circular guide rail (202).

6. A device for preparing potassium sulfite according to claim 5, characterized in that: A vertically arranged cylinder (5) is fixed inside the potassium sulfite reaction kettle (1), a spiral guide groove (501) is provided on the outer side of the cylinder (5), the cylinder (5) passes through the circular ring bracket (4), a spiral guide groove (501) is provided on the outer side of the cylinder (5), a horizontally arranged guide rod (403) is fixed on the inner wall of the circular ring bracket (4), and one end of the guide rod (403) extends into the spiral guide groove (501).

7. A device for preparing potassium sulfite according to claim 6, characterized in that: The top end of the liquid guiding curved pipe (301) is connected to a vertical conduit (302), and a nozzle (303) is fixed to the top end of the vertical conduit (302).

8. A device for preparing potassium sulfite according to claim 7, characterized in that: A stirring branch (304) is installed outside the vertical conduit (302), and the heights of the vertical conduits (302) are different.

9. A device for preparing potassium sulfite according to claim 1, characterized in that: The device also includes a pressure gauge, a thermometer, a regulating valve, and a flow meter. The outlet circulation pipeline of the potassium sulfite circulation pump is provided with a PH online detection.

10. A method for preparing potassium sulfite, using a device for preparing potassium sulfite as claimed in any one of claims 1 to 9, characterized in that: The following steps are involved: S1: The potassium hydroxide delivery pump delivers potassium hydroxide into the potassium sulfite reaction kettle (1), and a quantitative amount of potassium hydroxide solution is added at one time through a liquid level meter; S2: The potassium hydroxide is circulated in the ejector (102) through the potassium sulfite circulation pump, and the circulating water of the reactor jacket (101) is turned on to control the reaction temperature; S3: Control the sulfur dioxide to flow into the ejector (102) through the conditional valve, and the sulfur dioxide and sodium hydroxide are fully mixed and reacted to generate potassium sulfite. The amount of sulfur dioxide added is controlled according to the pressure and temperature of the potassium sulfite reactor (1); S4: PH online detection: When the pH of potassium sulfite in the potassium sulfite reactor (1) is close to neutral, the sulfur dioxide is turned off and the potassium sulfite solution is sent to the potassium sulfite temporary storage tank through the outlet branch line of the potassium sulfite circulation pump.

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