CN205442932U - Near zero emission processing system of high concentration organic waste water and mud - Google Patents

Abstract

The utility model discloses a near zero emission processing system of high concentration organic waste water and mud belongs to chemical industry and environmental protection technology field. Use the supercritical water oxidation technique as the core, waste water and mud at first grind through mud homogeneity pump, then utilize the high pressure plunger pump pressurization, transport that follow -up pipeline preheats and mix with oxygen, take place the supercritical water oxidation reaction at reactor. Reaction back fluid carries out the separation of infusibility solid, gas in proper order through self -cleaning filter, vapour and liquid separator after pressure reduction means steps down, get into (MVR) the crystallization of mechanical type vapor recompression technique afterwards, carries out soluble salt's crystallization, realizes that the near zero emission of feed handles. Simultaneously, use conventional water processing technique (for example coagulating sedimentation, membrane biotechnology, membrane technology and so on) to assist the SCWO technique, suitably reduce the operating parameter of SCWO reactor, will remain partly COD and transfer to conventional water department technique and handle, effectively reduced the running cost.

Description

A near-zero discharge treatment system for high-concentration organic wastewater and sludge

technical field

The utility model belongs to the technical field of chemical industry and environmental protection, and in particular relates to a near-zero discharge treatment system for high-concentration organic waste water and sludge with supercritical water oxidation technology as the core.

Background technique

Under normal circumstances, water exists in three common states of steam, liquid water and ice. Liquid water is a polar solvent whose density hardly changes with the increase of pressure. It can dissolve most electrolytes including salts. And most organic matter is slightly soluble or insoluble. Supercritical water refers to water in a special state where the temperature and pressure are higher than its critical point (374.15°C, 22.1MPa). The properties of supercritical water will change greatly, and its density, dielectric constant, diffusion coefficient and thermal conductivity are different from ordinary water. Moreover, the solubility of organic substances and gases in supercritical water is significantly improved.

Supercritical water oxidation technology (SCWO technology) utilizes the special properties of water in the supercritical state, so that oxidants and organic substances are completely dissolved in supercritical water and undergo a homogeneous oxidation reaction, quickly and thoroughly transforming organic substances It is a harmless small molecule compound such as carbon dioxide, nitrogen and water. Compared with other traditional treatment technologies for highly difficult and biodegradable organic wastewater, supercritical water oxidation technology has the following advantages:

1. High oxidation efficiency, the theoretical removal rate of organic matter can reach more than 99.9%;

2. The reaction time is short, the equipment structure is simple, and the floor area is small;

3. After the concentration of organic matter reaches 3%, the system can realize self-heating.

Supercritical water oxidation technology has been applied at home and abroad, but when the treatment object is petrochemical sludge, there are still several problems to be solved, mainly in:

Although theoretically, the application of SCWO technology can make the COD removal rate of organic wastewater (sludge) as high as 99.9%, but this data is realized under a very ideal reaction environment, including a higher oxidation coefficient (3 to 10 times ), higher reaction conditions (600~700°C, 27~29MPa), longer reaction residence time (100~150s). In this case, the material selection of the system pipeline, the supply of oxygen and the size of the reactor must be increased, which requires a very high increase in cost to achieve, and the economics of SCWO technology for sewage treatment will be greatly reduced. Therefore, it is necessary to use other sewage treatment methods to assist SCWO technical treatment.

The sludge contains a lot of organic matter that is easy to coke. If the heating furnace is used to preheat the sludge feed according to the traditional method, the temperature of the pipe heating is extremely high, and the organic matter in the water-containing sludge has a higher concentration on the high-temperature wall surface. coking tendency. If the monitoring is not timely, coking will occur on the wall, causing the wall temperature to rise sharply, causing the wall to overheat and burst the tube or block the tube.

When the amount of sludge to be treated is large, the entire system process is relatively long. If the reactor inlet temperature is insufficient and needs to be reheated, if the gas heating furnace is used for heating, the heating amount cannot be controlled. If an electric heating furnace is used, the start-up time of electric heating is longer, and the thermal inertia is strong, so it is impossible to achieve rapid heating. Therefore, there is a need for a device capable of controlling the heating power and rapidly replenishing heat.

The SCWO process is an exothermic reaction process. Studies have shown that when the concentration of organic matter reaches 3%, the heat released by the reaction is sufficient to preheat the material before entering the reactor. However, since the SCWO reaction is a highly corrosive environment with high temperature, high pressure, and high oxygen content, the requirements for the selection of equipment in the system are extremely high. Generally, nickel-based alloys are selected as materials for core equipment such as reactors, and the price of nickel-based alloys is relatively high. , Many materials have not even been domestically produced, so it will result in a higher initial investment.

Utility model content

In order to overcome the above-mentioned defects in the prior art, the purpose of this utility model is to provide a near-zero discharge treatment system for high-concentration organic wastewater and sludge. , Solve the problems of corrosion and salt deposition, improve economy, and achieve near-zero emissions.

The utility model is realized through the following technical solutions:

A near-zero discharge treatment system for high-concentration organic wastewater and sludge, including a wastewater transport unit, a reaction unit, an oxygen supply unit, and a post-treatment unit;

The wastewater transport unit includes a sludge storage tank and a sludge buffer tank, and a homogeneous emulsification pump is installed on the pipeline between the sludge storage tank and the sludge buffer tank; the reaction unit includes a heat exchanger and a tubular reactor. The pipeline connecting the sludge buffer tank and the heat exchanger is equipped with a high-pressure variable frequency plunger pump. The outlet end of the tube side of the heat exchanger is connected to the inlet end of the tubular reactor, and the outlet end of the tubular reactor is connected to the The inlet port on the shell side is connected; the oxygen supply unit is connected to the tubular reactor;

The post-processing unit includes a pressure reducer, a self-cleaning filter, a gas-liquid separator and an MVR crystallization unit; the shell-side outlet of the heat exchanger is connected to the inlet of the pressure reducer, and the outlet of the pressure reducer is connected to the self-cleaning filter The inlet port of the self-cleaning filter is connected to the gas-liquid separator, and the liquid outlet port at the bottom of the gas-liquid separator is connected to the inlet port of the MVR crystallization unit.

The oxygen supply unit includes a liquid oxygen storage tank, a cryogenic liquid oxygen pump, a liquid oxygen vaporizer, an oxygen buffer tank and an oxygen mixer; the outlet end of the liquid oxygen storage tank is connected to the inlet end of the cryogenic liquid oxygen pump, and the cryogenic liquid oxygen pump The outlet port of the liquid oxygen vaporizer is connected to the shell-side inlet port of the liquid oxygen vaporizer, the shell-side outlet port of the liquid oxygen vaporizer is connected to the inlet port of the oxygen buffer tank, the outlet port of the oxygen buffer tank is connected to the inlet port of the oxygenation mixer, and the oxygenation mixer Connected to the gas inlet port of the tubular reactor.

The post-processing unit also includes an advanced processing unit, and the outlet of the MVR crystallization unit is connected with the inlet of the advanced processing unit.

The advanced treatment unit adopts activated carbon adsorption device, ultrafiltration device or membrane concentration device.

The self-cleaning filter adopts a rotary scraper type self-cleaning filter.

The solute at the inlet of the MVR crystallization unit is sodium chloride, sodium sulfate or sodium carbonate.

An exhaust port is provided on the top of the gas-liquid separator.

Compared with the prior art, the utility model has the following beneficial technical effects:

The near-zero discharge treatment system for high-concentration organic wastewater and sludge disclosed by the utility model includes a wastewater transport unit, a reaction unit, an oxygen supply unit, and a post-processing unit; the wastewater transport unit first passes the wastewater and sludge through a homogeneous emulsification pump For grinding, the insoluble solids in the sludge can be firstly ground to the designed particle size to prevent blockage caused by salt deposition in the subsequent pipeline; And mixed with the oxygen from the oxygen supply unit, the supercritical water oxidation reaction occurs in the tubular reactor in the reaction unit. The gas-liquid separator separates insoluble solids and gases, and then enters the MVR (mechanical recompression) crystallization unit for crystallization of soluble salts to achieve near-zero discharge of feed materials. Through the system of the utility model, the heavy metal-containing solid produced by SCWO treatment can be effectively separated, and the stable landfill can be realized or entrusted to a qualified processing unit for safe landfill; the inorganic salt produced by MVR crystallization is recovered by the glass factory and the sodium sulfate factory , The gas generated during the whole process is mainly carbon dioxide and nitrogen, which can be discharged into the air or collected systematically.

Furthermore, the utility model innovatively uses a deep processing unit in the post-processing unit, and the outlet liquid of the deep processing unit can be discharged up to the standard. The advanced treatment unit uses conventional water treatment technologies, such as activated carbon adsorption, membrane concentration treatment or membrane biotechnology. The deep treatment unit can assist the SCWO technology, appropriately reduce the operating parameters of the SCWO reactor, and hand over a part of the residual COD to the conventional water treatment technology, which effectively reduces the operating cost. possible.

Furthermore, the self-cleaning filter adopts a rotary scraper type self-cleaning filter, which has extremely high filtration accuracy and can be operated continuously and under pressure, and its function is to filter out insoluble solids in the water.

Description of drawings

Fig. 1 is a structural schematic diagram of a near-zero discharge treatment system for high-concentration organic wastewater and sludge of the present invention.

Among them, 1 is a sludge storage tank; 2 is a homogeneous emulsification pump; 3 is a sludge buffer tank; 4 is a high-pressure frequency conversion plunger pump; 5 is a heat exchanger; 6 is a tubular reactor; 7 is a pressure reducer; 8 is a self-cleaning filter; 9 is a gas-liquid separator; 10 is an MVR crystallization unit; 11 is an advanced processing unit; 12 is a liquid oxygen storage tank; 13 is a low-temperature liquid oxygen pump; 14 is a liquid oxygen vaporizer; 15 is an oxygen buffer Tank, 16 is oxygen mixer.

detailed description

The utility model will be further described in detail below in conjunction with specific embodiments, which are explanations of the utility model rather than limitations.

Referring to Figure 1, a near-zero discharge treatment system for high-concentration organic wastewater and sludge based on supercritical water oxidation technology of the present invention, the whole system includes a wastewater transport unit, a reaction unit, an oxygen supply unit and post-treatment unit.

The wastewater transport unit includes a sludge storage tank 1 and a sludge buffer tank 3, and a homogeneous emulsification pump 2 is provided on the pipeline between the sludge storage tank 1 and the sludge buffer tank 3; the reaction unit includes a heat exchanger 5 and The tubular reactor 6 is provided with a high-pressure variable frequency plunger pump 4 on the pipeline connecting the sludge buffer tank 3 and the heat exchanger 5, and the outlet end of the tube side of the heat exchanger 5 is connected to the inlet end of the tubular reactor 6, The outlet end of the tubular reactor 6 is connected to the shell-side inlet end of the heat exchanger 5; the oxygen supply unit is connected to the tubular reactor 6;

The post-processing unit includes a pressure reducer 7, a self-cleaning filter 8, a gas-liquid separator 9 and an MVR crystallization unit 10; the shell-side outlet port of the heat exchanger 5 is connected to the inlet port of the pressure reducer 7, and the The outlet end is connected to the inlet end of the self-cleaning filter 8, and the clean fluid outlet end of the self-cleaning filter 8 is connected to the gas-liquid separator 9, and an exhaust port is provided on the top of the gas-liquid separator 9, and a liquid outlet is provided at the bottom , the liquid outlet port at the bottom of the gas-liquid separator 9 is connected to the inlet port of the MVR crystallization unit 10 . The post-processing unit also includes a deep processing unit 11 , and the outlet of the MVR crystallization unit 10 is connected to the entrance of the deep processing unit 11 .

The oxygen supply unit includes a liquid oxygen storage tank 12, a cryogenic liquid oxygen pump 13, a liquid oxygen vaporizer 14, an oxygen buffer tank 15 and an oxygenation mixer 16; the outlet end of the liquid oxygen storage tank 12 and the inlet of the cryogenic liquid oxygen pump 13 The outlet end of the cryogenic liquid oxygen pump 13 is connected with the inlet end of the shell side of the liquid oxygen vaporizer 14, the outlet end of the shell side of the liquid oxygen vaporizer 14 is connected with the inlet end of the oxygen buffer tank 15, and the outlet end of the oxygen buffer tank 15 is connected with the The inlet end of the oxygen mixer 16 is connected, and the oxygen mixer 16 is connected with the gas inlet end of the tubular reactor 6 .

Preferably, the solute composition at the inlet of the MVR crystallization unit 10 is sodium chloride, sodium sulfate or sodium carbonate.

The self-cleaning filter 8 adopts a rotary scraper type self-cleaning filter, which has extremely high filtration accuracy and can operate continuously and under pressure. Its function is to filter out insoluble solids in the water.

The advanced treatment unit 11 uses conventional water treatment technology, which can be activated carbon adsorption, membrane biotechnology or membrane technology. Its function is to deal with the remaining COD that has not been dealt with in the supercritical water oxidation reaction, thereby reducing the main reaction parameters and reducing the cost.

The operating principle of the system described in the utility model is as follows:

(1) The organic wastewater and sludge are stored in the sludge storage tank 1, and after being grinded by the homogeneous emulsification pump 2, the particle size set value is reached. The solid insoluble sludge particles smaller than this particle size can ensure the normal flow rate in the system Smooth flow in each tube without deposition. The ground water-containing sludge enters the sludge buffer tank 3 for further particle size detection and adding alkali to adjust the pH value. Then it passes through the high-pressure variable frequency plunger pump 4 to enter the heat exchanger 5, and the cold sludge exchanges heat with an intermediate medium with an inlet temperature of 500°C, and then enters the tubular reactor 6. The liquid oxygen in the liquid oxygen storage tank 12 first passes through the low-temperature liquid oxygen pump 13 and enters the liquid oxygen vaporizer 14 to change into a gaseous state and enters the oxygen buffer tank 15, and then enters the tubular reactor 6 to mix and react with organic wastewater.

(2) Oxygen and organic matter in wastewater react homogeneously under supercritical conditions (560°C, 26MPa) in tubular reactor 6, and organic matter is quickly and completely oxidized and decomposed into CO ₂ , N ₂ , H ₂ O. After the reaction The high-temperature fluid enters the heat exchanger and is cooled to 80°C by exchanging heat with the intermediate medium water. Then it enters the pressure reducer 7 for decompression, and the outlet condition of the pressure reducer 7 is (80°C, 0.4MPa).

(3) After the reaction, the fluid passes through the self-cleaning filter 8 (80°C, 0.4MPa) to separate and discharge the insoluble solids, and then the fluid enters the gas-liquid separator 9 for gas-liquid separation, and the separated gas is mainly _CO2 and _N2 , can be directly discharged to the air, and the separated liquid enters the MVR crystallization unit 10. The processing capacity of the MVR crystallization unit 10 is 2.13t/h, and the evaporation capacity is 2t/h. The system can realize continuous feeding. The soluble salts in the solution (mainly sodium chloride, sodium sulfate and sodium carbonate) are separated after evaporation and crystallization. Then the fluid enters the advanced treatment unit 11, whose role is to further treat the remaining organic matter that SCWO has not disposed of. The advanced treatment unit 11 is a conventional water treatment device, which can be activated carbon adsorption, biochemical treatment, ultrafiltration or membrane concentration technology.

Claims (7)

1. a high concentrated organic wastewater and the near-zero release processing system of mud, it is characterised in that include waste water sending unit, reaction member, oxygen supply unit and post-processing unit；

Waste water sending unit includes mud storage tank (1) and mud surge tank (3), and the pipeline between mud storage tank (1) and mud surge tank (3) is provided with homogenizing emulsifying pump (2)；Reaction member includes heat exchanger (5) and tubular reactor (6), the pipeline that mud surge tank (3) is connected with heat exchanger (5) is provided with high-pressure frequency-conversion plunger displacement pump (4), the tube side port of export of heat exchanger (5) is connected with the arrival end of tubular reactor (6), and the port of export of tubular reactor (6) is connected with the shell-side inlet end of heat exchanger (5)；Oxygen supply unit is connected with tubular reactor (6)；

Post-processing unit includes reducing transformer (7), self-cleaning filter (8), gas-liquid separator (9) and MVR crystalline element (10)；The shell-side outlet end of heat exchanger (5) is connected with the arrival end of reducing transformer (7), the port of export of reducing transformer (7) is connected with the arrival end of self-cleaning filter (8), the clean fluid port of export of self-cleaning filter (8) is connected with gas-liquid separator (9), and the liquid outlet end of gas-liquid separator (9) bottom is connected with the arrival end of MVR crystalline element (10).

The near-zero release processing system of high concentrated organic wastewater the most according to claim 1 and mud, it is characterized in that, described oxygen supply unit includes liquid oxygen storage tank (12), low-temperature liquid oxygen pump (13), liquid oxygen carburetor (14), oxygen surge tank (15) and adds oxygen mixer (16)；The port of export of liquid oxygen storage tank (12) is connected with the arrival end of low-temperature liquid oxygen pump (13), the port of export of low-temperature liquid oxygen pump (13) is connected with liquid oxygen carburetor (14) shell-side inlet end, the shell-side outlet end of liquid oxygen carburetor (14) is connected with the arrival end of oxygen surge tank (15), the port of export of oxygen surge tank (15) is connected with the arrival end adding oxygen mixer (16), adds oxygen mixer (16) and is connected with the gas access end of tubular reactor (6).

The near-zero release processing system of high concentrated organic wastewater the most according to claim 1 and mud, it is characterized in that, post-processing unit also includes that advanced treatment unit (11), the outlet of MVR crystalline element (10) are connected with the entrance of advanced treatment unit (11).

The near-zero release processing system of high concentrated organic wastewater the most according to claim 3 and mud, it is characterised in that advanced treatment unit (11) uses absorbent charcoal adsorber, ultrafiltration apparatus or film condensing device.

The near-zero release processing system of high concentrated organic wastewater the most according to claim 1 and mud, it is characterised in that self-cleaning filter (8) uses rotary cutter self-cleaning filter.

The near-zero release processing system of high concentrated organic wastewater the most according to claim 1 and mud, it is characterised in that the solute of MVR crystalline element (10) import department is sodium chloride, sodium sulfate or sodium carbonate.

The near-zero release processing system of high concentrated organic wastewater the most according to claim 1 and mud, it is characterised in that be provided with air vent at the top of gas-liquid separator (9).