A hazardous waste pretreatment system containing thionyl chloride and high-chlorine residue

Abstract

The present invention provides a hazardous waste pretreatment system containing thionyl chloride and high-chlorine residue, comprising: a primary reactor, the primary reactor comprising a hydrolysis and crushing zone located at the lower part thereof and a spray demisting zone located above the hydrolysis and crushing zone, wherein the hydrolysis and crushing zone is used to hydrolyze the thionyl chloride and high-chlorine residue in the hazardous waste in an absorption liquid, and the spray demisting zone is used to generate a spray to remove volatile acid gas generated by hydrolysis; and a secondary reactor, the water inlet of the secondary reactor is connected to the water outlet of the primary reactor, the water outlet of the secondary reactor is connected to the spray demisting zone of the primary reactor, and the secondary reactor is connected to an alkali liquid tank. The hazardous waste pretreatment system containing thionyl chloride and high-chlorine residue provided by the present invention simultaneously realizes the hydrolysis and deactivation of thionyl chloride and the stabilization and dechlorination of high-chlorine residue, the equipment unit is compact, and the investment and operation costs are low.

Description

Technical Field

[0001] The invention relates to the field of hazardous waste treatment, and in particular to a hazardous waste pretreatment system containing thionyl chloride and high-chlorine residue. Background Art

[0002] Hazardous waste, also known as hazardous waste, refers to waste that is listed in the national hazardous waste list or identified as having hazardous characteristics according to the national hazardous waste identification standards and identification methods. Hazardous waste has harmful characteristics such as toxicity, explosiveness, flammability, corrosiveness, chemical reactivity, infectiousness, and radioactivity. In view of its environmental risks and threats to human health, hazardous waste has become one of the major environmental problems facing my country.

[0003] Incineration of hazardous waste is a method of treating hazardous waste with the most obvious reduction effect, the most thorough harmlessness, and effective utilization of incineration heat, so it has been widely used. Due to the presence of highly corrosive and highly volatile acid mist, the traditional hazardous waste incineration process cannot directly treat hazardous waste containing thionyl chloride, and such hazardous waste is often mixed with high-chlorine residues, so the physical and chemical system in the field of drug disposal is also not suitable for its treatment.

[0004] Therefore, it is necessary to provide a new safe and stable hazardous waste pretreatment system to solve the volatilization and heat release problems of acid mist in wastes containing thionyl chloride and high-chlorine residues, as well as the problem that high-chlorine residues cannot directly enter the thermal treatment system. Summary of the invention

[0005] A series of simplified concepts are introduced in the Summary of the Invention, which will be further described in detail in the Detailed Description of the Invention. The Summary of the Invention does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the scope of protection of the claimed technical solution.

[0006] In order to solve the above problems, the present invention provides a hazardous waste pretreatment system containing thionyl chloride and high-chlorine residue, comprising:

[0007] A primary reactor, the primary reactor comprising a hydrolysis and crushing zone located at the lower part thereof and a spray and demisting zone located above the hydrolysis and crushing zone, wherein the hydrolysis and crushing zone is used to hydrolyze thionyl chloride and high-chlorine residue in the hazardous waste in an absorption liquid, and the spray and demisting zone is used to generate a spray to remove volatile acid gas generated by hydrolysis; and

[0008] A secondary reactor, wherein the water inlet of the secondary reactor is connected to the water outlet of the primary reactor, the water outlet of the secondary reactor is connected to the spray demisting area of ​​the primary reactor, and the secondary reactor is connected to an alkali solution tank.

[0009] Exemplarily, the primary reactor is provided with a stirring device extending to the hydrolysis and fragmentation zone, and a fragmentor is provided at the bottom of the stirring device.

[0010] Exemplarily, the bottom of the primary reactor is conical, and a raised area is provided on the inner wall of the conical bottom, and the raised area is used to cooperate with the crusher to enhance the collision crushing of the high-chlorine residue.

[0011] Exemplarily, the spray demisting zone includes a spray device disposed at the top of the primary reactor and a hollow ball filler layer disposed below the spray device.

[0012] Exemplarily, the second reactor is connected to a first alkali liquid tank. When the pH value of the absorption liquid in the secondary reactor drops below 9, the alkali liquid in the first alkali liquid tank is introduced into the secondary reactor. When the pH value of the absorption liquid in the secondary reactor rises above 12, the introduction of the alkali liquid is stopped.

[0013] Exemplarily, it also includes a washing and deacidification tower connected to the primary reactor and / or the secondary reactor, and the washing and deacidification tower is used to treat the volatile acid gas discharged from the primary reactor and / or the secondary reactor.

[0014] Exemplarily, the washing and deacidification tower includes a first washing and deacidification tower and a second washing and deacidification tower which are sequentially connected in the flow direction of the volatile acid gas.

[0015] Exemplarily, the first washing and deacidification tower is connected to a second alkali liquid tank.

[0016] Exemplarily, when the pH value of the absorption liquid in the first washing and deacidification tower drops below 9, the alkali liquid in the second alkali liquid tank is introduced into the first washing and deacidification tower, and when the pH value of the absorption liquid in the first washing and deacidification tower rises above 12, the introduction of the alkali liquid is stopped.

[0017] Exemplarily, it also includes a fan connected to the washing and deacidification tower, and the fan is used to provide negative pressure power for the flow of the volatile acid gas.

[0018] Exemplarily, the primary reactor and / or the secondary reactor has a polytetrafluoroethylene or butyl rubber lining.

[0019] Exemplarily, the outlet water of the primary reactor is pumped into the secondary reactor by an inlet pump.

[0020] Exemplarily, the effluent from the secondary reactor is pumped to the spray demisting area of ​​the primary reactor by a circulation pump.

[0021] The hazardous waste pretreatment system containing thionyl chloride and high-chlorine residue provided by the invention realizes the hydrolysis deactivation of thionyl chloride and the stabilization dechlorination of high-chlorine residue at the same time, and the equipment unit is compact and the investment and operation costs are low. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The following drawings of the present invention are used to understand the present invention as part of the present invention. The embodiments of the present invention are shown in the drawings and the description thereof is used to explain the principle of the present invention.

[0023] In the attached figure:

[0024] Figure 1 Schematic diagram of a hazardous waste pretreatment system containing thionyl chloride and high-chlorine residue according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present invention. However, it is apparent to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present invention, some technical features well known in the art are not described.

[0026] In order to fully understand the present invention, a detailed structure will be presented in the following description to illustrate a hazardous waste pretreatment system containing thionyl chloride and high-chlorine residues proposed by the present invention. Obviously, the implementation of the present invention is not limited to the specific details familiar to those skilled in the art of hazardous waste incineration technology. The preferred embodiments of the present invention are described in detail below, but in addition to these detailed descriptions, the present invention may also have other embodiments and should not be interpreted as being limited to the embodiments presented here.

[0027] It should be understood that the purpose of the terms used herein is only to describe specific embodiments and is not intended to limit the present invention. The singular forms "a", "an", and "said / the" are also intended to include plural forms unless the context clearly indicates otherwise. When the terms "comprise" and / or "include" are used in this specification, they indicate the presence of the features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof. The terms "upper", "lower", "front", "back", "left", "right" and similar expressions used in the present invention are for illustrative purposes only and are not limiting.

[0028] Due to the presence of highly corrosive and volatile acid mist, the traditional hazardous waste incineration process cannot directly treat hazardous waste containing thionyl chloride, and this type of hazardous waste is often mixed with high-chlorine residues. Therefore, the physical and chemical systems in the field of drug disposal are also not suitable for its treatment.

[0029] In order to solve the problems existing in the prior art, the present invention provides a hazardous waste pretreatment system containing thionyl chloride and high-chlorine residue, the hazardous waste pretreatment system comprising: a primary reactor, the primary reactor comprising a hydrolysis and crushing zone located at the lower part thereof and a spray demisting zone located above the hydrolysis and crushing zone, wherein the hydrolysis and crushing zone is used to hydrolyze the thionyl chloride and high-chlorine residue in the hazardous waste in an absorption liquid, and the spray demisting zone is used to generate a spray to remove volatile acid gas generated by hydrolysis; and a secondary reactor, the water inlet of the secondary reactor is connected to the water outlet of the primary reactor, the water outlet of the secondary reactor is connected to the spray demisting zone of the primary reactor, and the secondary reactor is connected to an alkali liquid tank.

[0030] The hazardous waste pretreatment system containing thionyl chloride and high-chlorine residue provided by the invention realizes the hydrolysis deactivation of thionyl chloride and the stabilization dechlorination of high-chlorine residue at the same time, and the equipment unit is compact and the investment and operation costs are low.

[0031] In order to fully understand the present invention, detailed structures and / or steps will be presented in the following description to illustrate the technical solutions proposed by the present invention. Preferred embodiments of the present invention are described in detail below, but in addition to these detailed descriptions, the present invention may also have other implementations.

[0032] A hazardous waste pretreatment system according to one embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

[0033] like Figure 1 As shown, the hazardous waste pretreatment system provided in this embodiment includes a primary reactor 1 and a secondary reactor 2. The primary reactor 1 includes a hydrolysis and crushing zone 3 located at the lower part thereof and a spray demisting zone 4 located above the hydrolysis and crushing zone 3. The hydrolysis and crushing zone 3 is used to hydrolyze the thionyl chloride and high-chlorine residue in the hazardous waste in the absorption liquid. The spray demisting zone 4 is used to generate a spray to remove the volatile acid gas generated by the hydrolysis.

[0034] The water outlet of the primary reactor 1 is connected to the water inlet of the secondary reactor 2, and the water outlet of the secondary reactor 2 is connected to the spray demisting area 4 of the primary reactor 1. When the system is running, firstly, the absorption liquid is introduced into the primary reactor 1 through the water supply pipeline, and the absorption liquid is, for example, water or alkali solution. After the liquid level is higher than the water outlet of the primary reactor, the water inlet pump 5 of the secondary reactor 2 is turned on to achieve water inflow into the two reactors at the same time; until both reactors reach the liquid level control line, the circulation pump 6 is started to make the outlet water of the secondary reactor 2 enter the spray demisting area 4 of the primary reactor through the water outlet of the secondary reactor 2, and spray downward to form a spray, thereby establishing the circulation of the absorption liquid in the two reactors.

[0035] After the liquid levels in the primary reactor 1 and the secondary reactor 2 are stable, the discharge port of the primary reactor 1 is opened to feed the primary reactor 1. As an example, the feed rate can be controlled according to the content of thionyl chloride in the hazardous waste to avoid overheating in a local area. After the discharge port is opened, the hazardous waste enters the hydrolysis and crushing zone 3, where the thionyl chloride is hydrolyzed into hydrogen chloride and sulfur dioxide in the absorption liquid. Since there is a stable liquid level in the primary reactor 1, most of the products are absorbed by water; the high-chlorine residue in the hazardous waste undergoes a hydrolysis reaction at the bottom of the primary reactor 1.

[0036] A stirring device 7 extending to the hydrolysis and crushing zone 3 is provided inside the primary reactor 1, and a crusher is provided at the bottom of the stirring device 7, and the crusher is used to cause the high-chlorine residue to collide and crush. In this embodiment, the bottom of the primary reactor 1 is conical, and a raised area is provided on the inner wall of the conical bottom, and the raised area is used to work in conjunction with the crusher to enhance the effect of collision and crushing and promote the efficiency of hydrolysis and dechlorination. After this treatment, the dechlorinated solid phase residue can be discharged through the discharge port at the bottom of the primary reactor 1 and enter the material pit of the hazardous waste treatment plant for preparation.

[0037] The volatile acid mist released from the hydrolysis and crushing zone 3 rises to the spray demisting zone 4, reacts with the spray and is absorbed. Specifically, the spray demisting zone 4 includes a spray device 8 disposed on the top of the primary reactor 1 and a hollow ball packing layer 9 disposed below the spray device 8. The acid mist reacts with the absorption liquid sprayed by the spray device 8 in the hollow ball packing layer 9.

[0038] The absorption liquid with acid mist then enters the secondary reactor 2 through the outlet of the primary reactor 1. The secondary reactor 2 is connected to a first alkali liquid tank 10. When the pH value of the absorption liquid in the secondary reactor drops below 9, the first dosing pump 11 is started to allow the alkali liquid in the first alkali liquid tank 10 to enter the secondary reactor 2 to adjust the pH value of the absorption liquid in the secondary reactor 2. When the pH value of the absorption liquid in the secondary reactor 2 rises to above 12, the first dosing pump 11 is turned off. The absorption liquid adjusted to a strong alkaline state in the secondary reactor 2 is driven by the circulation pump 6 to flow to the spray demisting area 4 of the primary reactor 1, and is sprayed out by the spray device 8, so as to continue to react with the volatile acid gas, thereby realizing the absorption liquid circulation process of the primary reactor 1 and the secondary reactor 2. As an example, a stirring device is also provided in the secondary reactor 2 to allow the alkali liquid to fully react with the absorption liquid. After the absorption liquid is saturated, it can enter the high-salt water system for evaporation treatment.

[0039] The pH value of the absorption liquid can be continuously adjusted by adjusting the secondary reactor 2, and the acid mist removal rate is high and the removal speed is fast. In addition, the overheating of the local area can be avoided by controlling the ratio of the absorption liquid to the waste liquid. The process has strong operability and large flexible adjustment space.

[0040] A small amount of escaped acid gas in the primary reactor 1 and / or the secondary reactor 2 enters the washing and deacidification tower, and is further absorbed by the washing and deacidification tower. As an example, the washing and deacidification tower includes a first washing and deacidification tower 12 and a second washing and deacidification tower 13 connected in sequence along the flow direction of the volatile acid gas, that is, the volatile acid gas discharged from the primary reactor and / or the secondary reactor first enters the first washing and deacidification tower 12, and then enters the second washing and deacidification tower 13. The fan 16 connected to the second washing and deacidification tower 13 provides negative pressure power for the flow of the volatile acid gas.

[0041] The first washing and deacidification tower 12 is connected to a second alkali liquid tank 14. In one embodiment, when the pH value of the absorption liquid in the first washing and deacidification tower 12 drops below 9, the second dosing pump 15 is started to allow the alkali liquid in the second alkali liquid tank 14 to enter the first washing and deacidification tower 12. When the pH value of the absorption liquid in the first washing and deacidification tower 12 rises above 12, the second dosing pump 15 is turned off. In this way, the pH value of the absorption liquid in the first washing and deacidification tower 12 can be adjusted to enhance the absorption effect of the acid mist.

[0042] As an example, the primary reactor and / or the secondary reactor has a polytetrafluoroethylene or butyl rubber lining.

[0043] Continue to refer Figure 1An exemplary workflow of the hazardous waste pretreatment system provided in this embodiment is as follows: first, about 3 tons of water are added to the primary reactor 1 as an absorption liquid; the water inlet pump 5 of the secondary reactor 2 is turned on to allow the absorption liquid to enter the secondary reactor 2; when about 2 tons of water are loaded into the secondary reactor 2, the water replenishment is stopped, and the circulation pump 6 is started to allow the absorption liquid to enter the spray demisting area 4 of the primary reactor 1 to establish a spray cycle of the two reactors; the stirring device 7 is turned on, and about 2 tons of waste (solid-liquid ratio is about 1:1) is added, and the solid-phase high-chlorine residue is hydrolyzed and dechlorinated at the bottom of the primary reactor 1, and the protrusions set on the trapezoidal crusher at the bottom of the stirring device 7 and the inner wall of the conical bottom strengthen the collision crushing and promote the hydrolysis dechlorination efficiency; a large amount of hydrogen chloride and sulfur dioxide produced by the hydrolysis of liquid-phase thionyl chloride are directly absorbed by the absorption liquid in the primary reactor 1, and the released acid mist is absorbed by the absorption liquid sprayed by the spray device 8 in the hollow ball packing layer 9 of the primary reactor 1; a small amount of escaped acid gas enters the first washing and deacidification tower 12 and the second washing and deacidification tower 13 for further treatment. After the above treatment, the solid residue after dechlorination enters the material pit of the hazardous waste treatment plant for mixing, the gas phase can meet the emission standards, and can also be connected to the plant's deodorization system. After the circulating water is saturated, it enters the high-salt water system for evaporation treatment.

[0044] The hazardous waste pretreatment system containing thionyl chloride and high-chlorine residue provided by the invention realizes the hydrolysis deactivation of thionyl chloride and the stabilization dechlorination of high-chlorine residue at the same time, and the equipment unit is compact and the investment and operation costs are low.

[0045] The present invention has been described by the above embodiments, but it should be understood that the above embodiments are only for the purpose of example and description, and are not intended to limit the present invention to the scope of the described embodiments. In addition, it can be understood by those skilled in the art that the present invention is not limited to the above embodiments, and more variations and modifications can be made according to the teachings of the present invention, and these variations and modifications all fall within the scope of the protection claimed by the present invention. The protection scope of the present invention is defined by the attached claims and their equivalents.

Claims

1. A hazardous waste pretreatment system containing thionyl chloride and high-chlorine residue, comprising: The primary reactor comprises a hydrolysis and crushing zone at the lower part thereof and a spraying and demisting zone above the hydrolysis and crushing zone, wherein: The hydrolysis and crushing zone is used to hydrolyze the thionyl chloride and high-chlorine residue in the hazardous waste in the absorption liquid, and the spray demisting zone is used to generate spray to remove the volatile acid gas generated by the hydrolysis; as well as A secondary reactor, wherein the water inlet of the secondary reactor is connected to the water outlet of the primary reactor, the water outlet of the secondary reactor is connected to the spray demisting area of ​​the primary reactor, and the secondary reactor is connected to an alkali liquid tank; The primary reactor is provided with a stirring device extending to the hydrolysis and crushing zone, and a crusher is provided at the bottom of the stirring device; the bottom of the primary reactor is conical, and a convex area is provided on the inner wall of the conical bottom, and the convex area is used to cooperate with the crusher to enhance the collision and crushing of the high-chlorine residue; The secondary reactor is also provided with a stirring device to allow the alkali solution and the absorption liquid to react fully.

2. The hazardous waste pretreatment system according to claim 1, characterized in that: The spray demisting zone comprises a spray device arranged on the top of the primary reactor and a hollow ball filler layer arranged below the spray device.

3. The hazardous waste pretreatment system according to claim 1, characterized in that: The secondary reactor is connected to a first alkali liquid tank. When the pH value of the absorption liquid in the secondary reactor drops below 9, the alkali liquid in the first alkali liquid tank is introduced into the secondary reactor. When the pH value of the absorption liquid in the secondary reactor rises above 12, the introduction of the alkali liquid is stopped.

4. The hazardous waste pretreatment system according to claim 1, characterized in that: It also includes a washing and deacidification tower connected to the primary reactor and / or the secondary reactor, and the washing and deacidification tower is used to treat the volatile acid gas discharged from the primary reactor and / or the secondary reactor.

5. The hazardous waste pretreatment system according to claim 4, characterized in that: The washing and deacidification tower comprises a first washing and deacidification tower and a second washing and deacidification tower which are sequentially connected in the flow direction of the volatile acid gas.

6. The hazardous waste pretreatment system according to claim 5, characterized in that: The first washing and deacidification tower is connected to a second alkali liquid tank.

7. The hazardous waste pretreatment system according to claim 6, characterized in that: When the pH value of the absorption liquid in the first washing and deacidification tower drops below 9, the alkali liquid in the second alkali liquid tank is introduced into the first washing and deacidification tower. When the pH value of the absorption liquid in the first washing and deacidification tower rises to above 12, the introduction of the alkali liquid is stopped.

8. The hazardous waste pretreatment system according to claim 4, characterized in that: It also includes a fan connected to the washing and deacidification tower, and the fan is used to provide negative pressure power for the flow of the volatile acid gas.

9. The hazardous waste pretreatment system according to claim 1, characterized in that: The primary reactor and / or the secondary reactor has a polytetrafluoroethylene or butyl rubber lining.

10. The hazardous waste pretreatment system according to claim 1, characterized in that: The outlet water of the primary reactor is pumped into the secondary reactor by a water inlet pump.

11. The hazardous waste pretreatment system according to claim 1, characterized in that: The effluent from the secondary reactor is pumped to the spray demisting area of ​​the primary reactor by a circulation pump.

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