Pyrohydrolysis cyanogen breaking device

Abstract

The utility model discloses a thermal hydrolysis cyanide breaking device, which relates to the technical field of wastewater treatment and comprises a cyanide breaking reactor, a wastewater heat exchanger, a pipeline mixer, a steam mixer, an instrument control valve and the like. After being heated by the wastewater heat exchanger, the wastewater enters a cyanide breaking reactor, and steam enters a steam mixer to heat the wastewater to a specified temperature and then enters the cyanide breaking reactor. The characteristic that the cyanide aqueous solution is easy to hydrolyze is utilized, so that the cyanide aqueous solution is hydrolyzed at the temperature of higher than 140 DEG C to produce sodium formate and ammonia, the toxicity of cyanide is eliminated, high-temperature wastewater discharged from the cyanide breaking reactor enters the wastewater heat exchanger to exchange heat with wastewater to be treated, and heat is recovered; the pressure of the reactor is controlled through a wastewater heat exchanger outlet wastewater outlet pipeline pressure regulating valve. The cyanide wastewater treatment device is reasonable in design, only a small amount of sodium hydroxide is needed for adjusting the pH of wastewater, no chemical agent needs to be added in other procedures, the cyanide wastewater treatment efficiency is improved, and the cost is saved.

Description

TECHNICAL FIELD

[0001] The utility model relates to wastewater treatment technical field, more specifically to a kind of hot hydrolysis cyanide breaking device technical field. BACKGROUND

[0002] A large amount of high cyanide (nitrile) wastewater is generated in the production process of hydrogen cyanide and subsequent cyanide (nitrile) product chain, and the wastewater contains a large amount of free cyanide such as hydrocyanic acid, hydroxyacetonitrile and imino-bis-acetonitrile and other organic cyanide. Since cyanide will produce hydrogen cyanide volatilization when it meets acid, it is toxic, so such wastewater must be broken cyanide to reduce the toxicity of wastewater. Current chemical oxidation cyanide breaking mainly includes alkaline chlorination cyanide breaking, ozone cyanide breaking, hydrogen peroxide cyanide breaking, sulfur dioxide-air oxidation method, etc. Among them, alkaline chlorination method adopts two-stage reaction to degrade cyanide, and the cyanide-containing wastewater treated can reach the first emission standard of "Integrated Wastewater Discharge Standard", but a large amount of acid and base and chlorine-containing oxidants such as chlorine and sodium hypochlorite are consumed, the treated wastewater has high chlorine ion content, and the consumption of chemical agents is large; ozone cyanide breaking process has the advantage of being friendly to the environment, but the ozone cyanide breaking device has high energy consumption for treating wastewater, and is mainly used for treating small-scale low-concentration cyanide-containing wastewater, and does not have the ability to treat high-concentration large-scale production wastewater; hydrogen peroxide cyanide breaking process is more suitable for treating low-concentration cyanide-containing wastewater, and soluble copper salt is used as catalyst in the treatment process.

[0003] The high-temperature hydrolysis cyanide breaking process does not need to add oxidants such as sodium hypochlorite, utilizes the easy hydrolysis characteristics of cyanide aqueous solution, and makes the cyanide aqueous solution hydrolyze to produce sodium formate and ammonia under the condition of more than 140℃, so as to eliminate the toxicity of cyanide. The cyanide breaking process is safe and reliable, the core equipment is reasonably designed, can successfully solve the wastewater treatment problem of fine chemical production enterprises, the total cyanide content of the wastewater after cyanide breaking is less than 20mg / l, and the chlorine ion content of the wastewater is not increased.

[0004] The patent with publication number US63665775A discloses the following content: a method for treating cyanide-containing wastewater by incineration, which mixes the wastewater with a treating agent containing a carbonyl compound such as formaldehyde to treat the cyanide-containing wastewater, and raises the temperature of the mixture in an oxygen-containing atmosphere to evaporate water and volatile substances, so as to burn the cyanide, decomposed cyanide components and other combustible materials, and reduce the waste gas of cyanide components. The toxic compounds of metals contained in the waste are also converted into harmless form and recovered, and no toxic components are discharged into the atmosphere or as waste. But this method has high equipment investment and high treatment cost.

[0005] Patent with publication number CN102115271A and patent name "A treatment method of high-concentration cyanide-containing or nitrile-containing organic wastewater" discloses the following content: including the following steps: firstly, under alkaline conditions, adding an oxidizing agent, cyanide in the wastewater is broken in the first step of oxidation; then, adding alkali to a certain pH value, and performing alkaline hydrolysis under a certain temperature; finally, under alkaline conditions, adding an oxidizing agent, cyanide in the wastewater is broken in the second step of oxidation. After the cyanide-containing or nitrile-containing organic wastewater is treated by the method of the present application, the total cyanide can be reduced to below 0.5 mg / L. However, this process has many operation steps, large amount of chemicals, and long operation time.

[0006] In the cyanide wastewater treatment disclosed in the above patent and the current high-cyanide-containing wastewater treatment technology, there is an urgent need for a treatment method with low cost and high efficiency to quickly and efficiently treat such cyanide-containing or nitrile-containing wastewater, and to reduce the chloride content in the wastewater as much as possible. Practical new type content

[0007] The present application provides a hot hydrolysis cyanide breaking device to solve the technical problems of low efficiency and high cost of existing cyanide wastewater treatment.

[0008] The present application specifically adopts the following technical solutions to achieve the above-mentioned purposes:

[0009] The present application provides a hot hydrolysis cyanide breaking device, which comprises a cyanide breaking reactor, a wastewater heat exchanger, a pipeline mixer, a steam inlet pipeline, a wastewater inlet pipeline, a pressure regulating valve, a wastewater outlet pipeline, a pressure transmitter temperature regulating valve, and a temperature transmitter.

[0010] The cyanide breaking reactor comprises a reactor shell, a wastewater outlet arranged at the top of the reactor shell, a steam inlet and a wastewater inlet arranged at the bottom of the reactor shell, and a steam mixer arranged in the bottom of the reactor shell and communicated with the steam inlet through a pipeline.

[0011] The wastewater inlet pipeline is communicated with the liquid inlet of the pipeline mixer, the pipeline mixer is provided with a sodium hydroxide dosing port, the liquid outlet of the pipeline mixer is communicated with the liquid inlet of the wastewater heat exchanger, the liquid outlet of the wastewater heat exchanger is communicated with the wastewater inlet of the cyanide breaking reactor, the steam inlet pipeline is communicated with the steam inlet at the bottom of the reactor shell, the wastewater outlet of the reactor shell is communicated with the hot water outlet of the wastewater heat exchanger through a pipeline, and the cold water outlet of the wastewater heat exchanger is communicated with the wastewater outlet pipeline.

[0012] The temperature regulating valve is arranged on the steam inlet pipeline, and the pressure regulating valve is arranged on the wastewater outlet pipeline.

[0013] Specifically, the device comprises a cyanide breaking reactor, a wastewater heat exchanger, a pH adjusting pipeline mixer, a steam mixer and instrument control valves, etc. The high cyanide (nitrile) containing wastewater is mixed with sodium hydroxide in the pipeline mixer, and the pH value is adjusted to about 10. After being heated by the wastewater heat exchanger, the wastewater enters the cyanide breaking reactor. At the same time, steam enters the steam mixer, and after heating the wastewater to the specified temperature, the wastewater enters the cyanide breaking reactor. By taking advantage of the easy hydrolysis of cyanide aqueous solution, the cyanide aqueous solution is hydrolyzed to produce sodium formate and ammonia at a temperature higher than 140℃, thereby eliminating the toxicity of cyanide. The high-temperature wastewater from the cyanide breaking reactor enters the wastewater heat exchanger to exchange heat with the wastewater to be treated, and the heat is recovered. The pressure of the reactor is controlled by the pressure regulating valve at the outlet of the wastewater heat exchanger.

[0014] The temperature control range of the cyanide breaking reactor is 140℃-165℃, and the pressure control of the cyanide breaking reactor is 0.7MPa(G). The cyanide breaking time is 2h-4h.

[0015] In one embodiment, the cyanide breaking reactor is a tower reactor, and the cyanide breaking reactor further comprises a pressure transmitter arranged at the upper section inside the reactor shell and a temperature transmitter arranged at the middle section inside the reactor shell. The pressure transmitter is electrically connected with the pressure regulating valve, and the temperature transmitter is electrically connected with the temperature regulating valve.

[0016] Specifically, the temperature of the cyanide breaking reactor is controlled by the steam amount regulating valve entering the reactor, and the pressure of the cyanide breaking reactor is controlled by the wastewater amount regulating valve exiting the reactor.

[0017] In one embodiment, the inside of the reactor shell is provided with a sieve plate distributor and a distribution plate assembly, and the sieve plate distributor is located above the distribution plate assembly.

[0018] In one embodiment, the distribution plate assembly comprises a plurality of circular distribution plates with the same structure arranged at intervals, each of the circular distribution plates is circumferentially provided with a plurality of first radial strip-shaped distribution holes, each of the circular distribution plates is circumferentially provided with a plurality of second radial strip-shaped distribution holes, the number of the first radial strip-shaped distribution holes is the same as that of the second radial strip-shaped distribution holes, and the first radial strip-shaped distribution holes and the second radial strip-shaped distribution holes are staggered.

[0019] In one embodiment, the length of the first radial strip-shaped distribution hole is greater than the length of the second radial strip-shaped distribution hole.

[0020] The width of each of the first radial strip-shaped distribution hole and the second radial strip-shaped distribution hole is 10cm, the length of each of the first radial strip-shaped distribution hole is 70% of the radius of the circular distribution plate, and the length of each of the second radial strip-shaped distribution hole is 30% of the radius of the circular distribution plate.

[0021] The sum of the areas of all the first radial strip-shaped distribution holes and all the second radial strip-shaped distribution holes is greater than 50% of the area of the circular distribution plate.

[0022] Specifically, the distribution plate assembly comprises a plurality of circular distribution plates, each of which is provided with strip-shaped distribution holes in the radial direction, the width of each strip-shaped distribution hole is 10 cm, and the length is about 70% of the radius of the distribution plate. An inclined guide plate is designed on each strip-shaped distribution hole, the angle between the inclined guide plate and the horizontal plane is about 60°, and the circular distribution plate is designed with 4-6 layers according to the size of the reactor. The area of the distribution holes of each circular distribution plate is greater than 50% of the area of the circular distribution plate.

[0023] In an embodiment, the sieve plate distributor comprises a plurality of circular sieve plates of the same structure arranged at equal intervals, and a plurality of sieve holes are uniformly distributed on each circular sieve plate in a rectangular array.

[0024] In an embodiment, the diameter of each sieve hole is 1-5 cm, and the total area of the sieve holes on each circular sieve plate is greater than 50% of the area of the circular sieve plate.

[0025] Specifically, three layers of sieve plate distributors are designed in the middle of the reactor, and the sieve holes of each sieve plate distributor are 1-5 cm.

[0026] In an embodiment, the bottom of the steam mixer is fixed to the inner bottom of the reactor shell by four legs.

[0027] The steam mixer comprises an inner cylinder and an outer cylinder sleeved outside the inner cylinder, both ends of the inner cylinder and the outer cylinder are closed, and the steam inlet at the bottom of the reactor shell is in communication with the inside of the inner cylinder through a pipeline passing through the outer cylinder.

[0028] In an embodiment, there is a gap between the inner cylinder and the outer cylinder, a plurality of inner circular holes are uniformly distributed on the side wall of the outer cylinder, and the total area of all the inner circular holes is greater than the cross-sectional area of the steam main pipe.

[0029] The side wall, top plate and bottom plate of the outer cylinder are provided with outer circular holes, and the total area of all the outer circular holes is greater than the cross-sectional area of the steam main pipe.

[0030] Specifically, a steam mixer is designed at the inner bottom of the cyanide breaking reactor, which is supported by four legs at the bottom and fixed to the bottom of the reactor. The steam mixer is composed of an inner cylinder and an outer cylinder. Steam enters the steam mixer from the top through the inner cylinder. The side of the inner cylinder is designed with inner circular holes with a diameter of 5-20 mm, and the total area of the inner circular holes is greater than the cross-sectional area of the steam main pipe. The side wall, top plate and bottom plate of the outer cylinder are designed with outer circular holes with a diameter of 5-20 mm, and the total area of the outer circular holes is greater than the cross-sectional area of the steam main pipe.

[0031] In one embodiment, the waste water heat exchanger is a shell-and-tube heat exchanger, the shell layer of the waste water heat exchanger is communicated with the waste water outlet pipeline, and the tube layer of the waste water heat exchanger is communicated with the waste water inlet pipeline.

[0032] The utility model discloses the beneficial effects are as follows:

[0033] The utility model discloses the reasonable in design, only a small amount of sodium hydroxide is needed to adjust waste water pH, and the rest process does not need to add any chemical reagent, improves cyanide waste water treatment efficiency and saves the cost, including cyanide breaking reactor, waste water heat exchanger, pH adjusting pipeline mixer, steam mixer and instrument control valve etc. High cyanide (nitrile) waste water is mixed through pipeline mixer and sodium hydroxide, and pH value is adjusted to about 10, and after heating through waste water heat exchanger, enters cyanide breaking reactor, and steam enters steam mixer, and after heating waste water to specified temperature, enters cyanide breaking reactor. Utilize the easy hydrolysis of cyanide aqueous solution's characteristics, make cyanide aqueous solution hydrolysis production sodium formate and ammonia under the condition that temperature is higher than 140 DEG C, and eliminate the toxicity of cyanide. The waste water from cyanide breaking reactor enters waste water heat exchanger, and exchanges heat with the waste water to be handled, and recovers heat.

[0034] 2, the temperature of cyanide breaking reactor is controlled by the steam amount adjusting valve entering the reactor, and the pressure of cyanide breaking reactor is controlled by the waste water amount adjusting valve out of the reactor. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the technical scheme of the embodiments of the utility model, the following will be to the drawings needed to be used in the embodiment simple introduction, should understand, the following drawings only shows some embodiments of the utility model, therefore should not be regarded as the limitation to the scope, for ordinary skilled person in the art comes, under the premise of not paying the creative labor, can also obtain other related drawings according to these drawings.

[0036] Figure 1 It is a kind of hot hydrolysis cyanide breaking device structure schematic view.

[0037] Figure 2 It is the structure schematic view of cyanide breaking reactor;

[0038] Figure 3 It is the structure schematic view of sieve plate distributor;

[0039] Figure 4 It is the structure schematic view of distribution plate assembly;

[0040] Figure 5 It is the structure schematic view of steam mixer;

[0041] Figure 6 It is Figure 5A cross-sectional structure schematic view at A-A;

[0042] Figure 7 A cross-sectional structure schematic view at A-A; Figure 5 A cross-sectional structure schematic view at B-B;

[0043] Figure 8 A cross-sectional structure schematic view at B-B; Figure 5 A cross-sectional structure schematic view at C-C;

[0044] Reference numerals: 1 - cyanogen breaking reactor, 2 - pressure transmitter, 3 - pipeline mixer, 4 - pressure regulating valve, 5 - waste water heat exchanger, 6 - steam mixer, 7 - temperature regulating valve, 8 - temperature transmitter, 9 - sieve tray distributor, 10 - distribution plate assembly. DETAILED DESCRIPTION

[0045] In order to make the technical problems, technical solutions and technical effects of the utility model clearer, the technical solutions in the utility model embodiments will be described clearly and completely in combination with the drawings in the utility model embodiments below. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. The components of the utility model embodiments described and shown in the drawings herein can be arranged and designed in various different configurations.

[0046] Therefore, the detailed description of the embodiments of the utility model provided in the drawings below is not intended to limit the scope of the claimed utility model, but only represents selected embodiments of the utility model. Based on the embodiments in the utility model, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the utility model.

[0047] It should be noted that: similar reference numerals and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. In addition, the terms "first", "second", etc. are only used for differentiation in description, and cannot be understood as indicating or implying relative importance.

[0048] In the description of the utility model embodiments, it should be noted that the orientation or position relationship indicated by the terms "inner", "outer", "upper", etc. is based on the orientation or position relationship shown in the drawings, or the orientation or position relationship commonly used when the utility model product is used, which is only for the convenience of describing the utility model and simplifying the description, and cannot be understood as indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, therefore, cannot be understood as a limitation on the utility model.

[0049] Example 1

[0050] As Figures 1 to 8As shown, the embodiment provides a hot hydrolysis cyanide breaking device, which comprises a cyanide breaking reactor 1, a wastewater heat exchanger 5, a pipeline mixer 3, a steam inlet pipeline, a wastewater inlet pipeline, a wastewater outlet pipeline, a pressure transmitter 2, a pressure regulating valve 4, a temperature regulating valve 7 and a temperature transmitter 8;

[0051] The cyanide breaking reactor 1 comprises a reactor shell, a wastewater outlet arranged at the top of the reactor shell, a steam inlet and a wastewater inlet arranged at the bottom of the reactor shell, and a steam mixer 6 arranged in the bottom of the reactor shell and communicated with the steam inlet through a pipeline;

[0052] The wastewater inlet pipeline is communicated with a liquid inlet of the pipeline mixer 3, the pipeline mixer 3 is provided with a sodium hydroxide feeding port, a liquid outlet of the pipeline mixer 3 is communicated with an inlet of the wastewater heat exchanger 5, an outlet of the wastewater heat exchanger 5 is communicated with the wastewater inlet of the cyanide breaking reactor 1, the steam inlet pipeline is communicated with the steam inlet at the bottom of the reactor shell, the wastewater outlet of the reactor shell is communicated with a hot water outlet of the wastewater heat exchanger 5 through a pipeline, and a cold water outlet of the wastewater heat exchanger 5 is communicated with the wastewater outlet pipeline;

[0053] The temperature regulating valve 7 is arranged on the steam inlet pipeline, and the pressure regulating valve 4 is arranged on the wastewater outlet pipeline.

[0054] Specifically, the device comprises the cyanide breaking reactor 1, the wastewater heat exchanger 5, the pH regulating pipeline mixer 3, the steam mixer 6 and instrument control valves. High-cyanide (nitrile) wastewater is mixed with sodium hydroxide through the pipeline mixer 3, and the pH value is adjusted to about 10, and then the wastewater is heated through the wastewater heat exchanger 5 and then enters the cyanide breaking reactor 1, while steam enters the steam mixer 6, and the wastewater is heated to a specified temperature and then enters the cyanide breaking reactor 1. By using the characteristics that cyanide aqueous solution is easy to hydrolyze, the cyanide aqueous solution is hydrolyzed to produce sodium formate and ammonia under the condition that the temperature is higher than 140℃, and the toxicity of cyanide is eliminated. The wastewater from the cyanide breaking reactor 1 enters the wastewater heat exchanger 5 and exchanges heat with the wastewater to be treated, and the heat is recovered. The pressure of the reactor is controlled through the pressure regulating valve 4 of the wastewater outlet pipeline of the wastewater heat exchanger 5 outlet.

[0055] The temperature control range of the cyanide breaking reactor 1 is 140℃-165℃, the pressure control of the cyanide breaking reactor 1 is 0.7MPa(G), and the cyanide breaking time is 2h-4h.

[0056] Example 2

[0057] This embodiment is further optimized on the basis of Example 1, specifically:

[0058] The cyanide breaking reactor 1 is a tower type reactor, and the cyanide breaking reactor 1 further comprises a pressure transmitter 2 arranged at an upper section inside the reactor shell, and a temperature transmitter 8 arranged at a middle section inside the reactor shell; the pressure transmitter 2 is electrically connected with a pressure regulating valve 4, and the temperature transmitter 8 is electrically connected with a temperature regulating valve 7.

[0059] Specifically, the temperature of the cyanide breaking reactor 1 is controlled by the steam amount regulating valve entering the reactor; and the pressure of the cyanide breaking reactor 1 is controlled by the wastewater amount regulating valve leaving the reactor.

[0060] The inside of the reactor shell is provided with a sieve plate distributor 9 and a distribution plate assembly 10, and the sieve plate distributor 9 is located above the distribution plate assembly 10.

[0061] The distribution plate assembly 10 comprises a plurality of circular distribution plates arranged at intervals and having the same structure, each circular distribution plate is circumferentially provided with a plurality of first radial strip-shaped distribution holes and a plurality of second radial strip-shaped distribution holes, the number of the first radial strip-shaped distribution holes is the same as that of the second radial strip-shaped distribution holes, and the first radial strip-shaped distribution holes and the second radial strip-shaped distribution holes are staggered.

[0062] The length of the first radial strip-shaped distribution hole is greater than the length of the second radial strip-shaped distribution hole;

[0063] The width of each first radial strip-shaped distribution hole and each second radial strip-shaped distribution hole is 10 cm, the length of each first radial strip-shaped distribution hole is 70% of the radius of the circular distribution plate, and the length of each second radial strip-shaped distribution hole is 30% of the radius of the circular distribution plate.

[0064] The sum of the areas of all the first radial strip-shaped distribution holes and all the second radial strip-shaped distribution holes is greater than 50% of the area of the circular distribution plate.

[0065] Specifically, the distribution plate assembly comprises a plurality of circular distribution plates, each circular distribution plate is radially provided with a strip-shaped distribution hole, the width of the strip-shaped distribution hole is 10 cm, and the length of the strip-shaped distribution hole is about 70% of the radius of the distribution plate, each strip-shaped distribution hole is designed with a guide plate inclined upward (at an angle of about 60° with the horizontal plane), and the circular distribution plate is designed with 4-6 layers of distribution plates according to the size of the reactor; the area of the distribution hole of each circular distribution plate is greater than 50% of the area of the circular distribution plate.

[0066] Example 3

[0067] This embodiment is further optimized on the basis of Example 2, specifically:

[0068] The sieve plate distributor 9 comprises a plurality of circular sieve plates arranged at equal intervals and having the same structure, and each circular sieve plate is uniformly provided with a plurality of sieve holes in a rectangular array.

[0069] The diameter of each sieve hole is 1-5 cm, and the total area of the sieve holes on each circular sieve plate is greater than 50% of the area of the circular sieve plate.

[0070] Specifically, three layers of sieve plate distributors are designed in the middle of the reactor, and the diameter of each sieve hole of each sieve plate distributor is 1-5 cm.

[0071] The bottom of the steam mixer 6 is fixed to the inner bottom of the reactor shell by four legs;

[0072] The steam mixer 6 comprises an inner cylinder and an outer cylinder sleeved outside the inner cylinder, and the two ends of the inner cylinder and the outer cylinder are closed. The steam inlet at the bottom of the reactor shell is connected to the inside of the inner cylinder through a pipeline passing through the outer cylinder.

[0073] There is a gap between the inner cylinder and the outer cylinder, and a plurality of inner holes are uniformly distributed on the side wall of the outer cylinder, and the total area of all the inner holes is greater than the cross-sectional area of the steam main pipe;

[0074] The side wall, top plate and bottom plate of the outer cylinder are provided with outer holes, and the total area of all the outer holes is greater than the cross-sectional area of the steam main pipe.

[0075] Specifically, the steam mixer 6 is designed at the bottom of the cyanide breaking reactor 1, and the steam mixer 6 is fixed to the bottom of the reactor by the four legs at the bottom. The steam mixer 6 is composed of an inner cylinder and an outer cylinder. Steam enters the steam mixer 6 from the top of the inner cylinder. The side of the inner cylinder is designed with inner holes with a diameter of 5-20 mm, and the total area of the inner holes is greater than the cross-sectional area of the steam main pipe. The side wall, top plate and bottom plate of the outer cylinder are designed with outer holes with a diameter of 5-20 mm, and the total area of the outer holes is greater than the cross-sectional area of the steam main pipe.

[0076] Example 4

[0077] This embodiment is further optimized based on Example 3, specifically:

[0078] The waste water heat exchanger 5 is a tube heat exchanger, and the shell layer of the waste water heat exchanger 5 is connected to the waste water outlet pipeline. The tube layer of the waste water heat exchanger 5 is connected to the waste water inlet pipeline.

[0079] Example 5

[0080] This embodiment is further optimized based on Example 4, specifically:

[0081] The processing capacity of the hot hydrolysis cyanide breaking device is 24 t / h, and the residence time of the waste water in the hot hydrolysis reactor is 3 hours. The cyanide (nitrile) composition of the waste water entering the device is: free cyanide 775 mg / l, total cyanide 788 mg / l, CODcr 4500 mg / l, and ammonia nitrogen 610 mg / l.

[0082] Start the hydrolysis device, start the wastewater feed pump, start the sodium hydroxide plunger pump to adjust the pH of the wastewater to 10, stop the feed after the reactor is full of wastewater, open the steam to slowly raise the temperature of the reactor, about 1 hour later, the temperature reaches the set temperature, the reactor pressure is controlled at 0.7Mpa. After the temperature and pressure are stable, start timing, 3 hours later, start the wastewater feed pump again, adjust the feed pump flow to 24t / h, ensure the reactor residence time is 3 hours, and maintain the reactor temperature and pressure. The temperature experiments were carried out at 140℃, 150℃ and 160℃ respectively. After 2 hours of stable experimental conditions, the ammonia nitrogen, total cyanide and free cyanide in the effluent were detected.

[0083] The experimental results: under the conditions of 140℃, 150℃ and 160℃, the total cyanide and free cyanide in the effluent were analyzed, and the test results are shown in Table 1 below.

[0084] Table 1 Decyanation test results

[0085] Sample name Ammonia nitrogen Free cyanide content (mg / l) Total cyanide content (mg / l) Influent 1# water sample 775 788 140°C reaction effluent 2# water sample 18.55 20.32 150°C reaction effluent 3# water sample 0.522 9.53 160°C reaction effluent 4# water sample 0.338 3.56

[0086] As can be seen from Table 1, when the above-mentioned cyanide-containing wastewater is treated in the decyanation reactor 1 (residence time 3 hours) at a reaction temperature of 150℃, the free cyanide and total cyanide contents in the cyanide-containing wastewater can be reduced to below 0.522mg / l and 9.53mg / l respectively, and the test goal is achieved.

Claims

1. A hot water decomposition and cyanide-breaking device, characterized in that, It includes a cyanide-breaking reactor (1), a wastewater heat exchanger (5), a pipeline mixer (3), a steam inlet pipeline, a wastewater inlet pipeline, a wastewater outlet pipeline, a pressure transmitter (2), a pressure regulating valve (4), a temperature regulating valve (7), and a temperature transmitter (8). The cyanide-breaking reactor (1) includes a reactor shell, a wastewater outlet located at the top of the reactor shell, a steam inlet and a wastewater inlet located at the bottom of the reactor shell, and a steam mixer (6) located at the bottom of the reactor shell and connected to the steam inlet via a pipe. The wastewater inlet pipe is connected to the liquid inlet of the pipe mixer (3), the pipe mixer (3) is provided with a sodium hydroxide dosing port, the liquid outlet of the pipe mixer (3) is connected to the liquid inlet of the wastewater heat exchanger (5), the liquid outlet of the wastewater heat exchanger (5) is connected to the wastewater inlet of the cyanide breaking reactor (1), the steam inlet pipe is connected to the steam inlet at the bottom of the reactor shell, the wastewater outlet of the reactor shell is connected to the hot water outlet of the wastewater heat exchanger (5) through a pipe, and the cold water outlet of the wastewater heat exchanger (5) is connected to the wastewater outlet pipe; The temperature regulating valve (7) is installed on the steam inlet pipe, and the pressure regulating valve (4) is installed on the wastewater outlet pipe.

2. The hot water decomposition and cyanide-breaking device according to claim 1, characterized in that, The cyanide-breaking reactor (1) is a tower reactor. The cyanide-breaking reactor (1) also includes a pressure transmitter (2) installed in the upper section of the reactor shell and a temperature transmitter (8) installed in the middle section of the reactor shell. The pressure transmitter (2) is electrically connected to the pressure regulating valve (4), and the temperature transmitter (8) is electrically connected to the temperature regulating valve (7).

3. The hot water decomposition and cyanide-breaking device according to claim 1, characterized in that, The reactor shell is provided with a sieve plate distributor (9) and a distribution plate assembly (10), with the sieve plate distributor (9) located above the distribution plate assembly (10).

4. The hot water decomposition and cyanide-breaking device according to claim 3, characterized in that, The distribution plate assembly (10) includes multiple circular distribution plates with the same structure arranged at intervals. Each circular distribution plate has multiple first radial strip distribution holes distributed around its circumference, and each circular distribution plate has multiple second radial strip distribution holes distributed around its circumference. The number of first radial strip distribution holes and second radial strip distribution holes is the same, and the first radial strip distribution holes and second radial strip distribution holes are staggered.

5. The hot water decomposition and cyanide-breaking device according to claim 4, characterized in that, The length of the first radial strip-shaped distribution hole is greater than the length of the second radial strip-shaped distribution hole. The width of each of the first radial strip distribution holes and each of the second radial strip distribution holes is 10cm, the length of each of the first radial strip distribution holes is 70% of the radius of the circular distribution plate, and the length of each of the second radial strip distribution holes is 30% of the radius of the circular distribution plate. The sum of the areas of all the first radial strip distribution holes and all the second radial strip distribution holes is greater than 50% of the area of ​​the circular distribution plate.

6. The hot water decomposition and cyanide-breaking device according to claim 3, characterized in that, The sieve plate distributor (9) includes multiple circular sieve plates with the same structure arranged at equal intervals, and each circular sieve plate has a number of sieve holes evenly distributed in a rectangular array.

7. The hot water decomposition and cyanide-breaking device according to claim 6, characterized in that, The diameter of each sieve hole is 1-5cm, and the total area of ​​the sieve holes on each circular sieve plate is greater than 50% of the area of ​​the circular sieve plate.

8. The hot water decomposition and cyanide-breaking device according to claim 1, characterized in that, The bottom of the steam mixer (6) is fixed to the inner bottom of the reactor shell by four legs; The steam mixer (6) includes an inner cylinder and an outer cylinder fitted outside the inner cylinder. Both ends of the inner cylinder and the outer cylinder are closed. The steam inlet at the bottom of the reactor shell is connected to the interior of the inner cylinder through a pipe passing through the outer cylinder.

9. The hot water decomposition and cyanide-breaking device according to claim 8, characterized in that, There is a gap between the inner cylinder and the outer cylinder. The outer cylinder has a number of inner circular holes evenly distributed on its side wall. The sum of the areas of all the inner circular holes is greater than the cross-sectional area of ​​the steam main pipe. The outer cylinder is provided with outer circular holes on its side walls, top plate, and bottom plate, and the sum of the areas of all the outer circular holes is greater than the cross-sectional area of ​​the steam main pipe.

10. A hot water decomposition and cyanide-breaking device according to claim 2, characterized in that, The wastewater heat exchanger (5) is a shell and tube heat exchanger. The shell of the wastewater heat exchanger (5) is connected to the wastewater outlet pipe; the tube of the wastewater heat exchanger (5) is connected to the wastewater inlet pipe.

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