CN-120383378-B - Wet oxidation wastewater treatment system and method

CN120383378BCN 120383378 BCN120383378 BCN 120383378BCN-120383378-B

Abstract

The invention discloses a wet oxidation wastewater treatment system and a wet oxidation wastewater treatment method, wherein the system comprises a multistage centrifugal pump; the system comprises a multistage centrifugal pump, a preheater positioned downstream of the multistage centrifugal pump, a heater positioned downstream of the preheater, and a reactor positioned downstream of the heater. The rotating speed of the multistage centrifugal pump is far lower than that of the traditional high-speed pump by more than 6600rpm, so that noise and vibration can be effectively reduced, and meanwhile, the loss of a motor bearing is delayed, thereby reducing the equipment maintenance cost and improving the stability and efficiency of a wet oxidation method. Meanwhile, the invention adopts the shell and tube heat exchanger, thereby reducing the explosion risk, improving the temperature of the waste water, greatly reducing the steam consumption of the subsequent heater, saving 2.4 tons of 3.2MPa steam per hour per 20m 3 of waste water according to actual operation, and creating huge economic benefit each year. The invention adopts the Q235B and TA9 explosion composite plate reactor, the comprehensive performance is better, and the long-term operation cost is greatly reduced.

Inventors

JIN XIPENG
FANG MIN
HAN GUOTAO
MENG QINGFENG
WANG ZHILEI
WANG ZIYUAN
LI PENG
Cheng Hongqu
HU HAIFENG
ZHANG ANZHI

Assignees

滨化集团股份有限公司

Dates

Publication Date: 20260512
Application Date: 20250609

Claims (8)

1. A method for treating wastewater is characterized in that the method comprises the steps of pressurizing wastewater in a wastewater storage unit by a multistage centrifugal pump in a wet oxidation wastewater treatment system, conveying the wastewater to a preheater for preheating, heating the wastewater in the preheater, and carrying out catalytic wet oxidation reaction in a reactor to realize wastewater purification; The wet oxidation wastewater treatment system comprises a multistage centrifugal pump; A preheater located downstream of the multistage centrifugal pump; A heater downstream of the preheater; and a reactor positioned downstream of the heater, wherein the reactor adopts Q235B and TA9 explosion composite plates; the multistage centrifugal pump adopts 10 stages of impellers; The motor of the multistage centrifugal pump is added with frequency conversion to adjust the rotating speed; the rotating speed of the multistage centrifugal pump is 1400-2980 rpm; The multistage centrifugal pump comprises a multistage impeller and a pump body, wherein the pump body comprises a suction section, a discharge section and a pump shaft, 5 impellers are respectively arranged in the suction section and the discharge section, the impellers are all arranged on the pump shaft, and two adjacent impellers are fixed and loose-proof through screws; the impeller directions of the suction section and the discharge section are opposite; the baffle plate is provided with a reflow hole; the suction section is provided with a fluid inlet; The discharge section is provided with a fluid outlet; sealing elements are respectively arranged at two ends of the pump shaft; The tube side medium of the preheater is wastewater pressurized by a multistage centrifugal pump; the shell side medium of the preheater is from water after the wet oxidation reaction of the reactor is completed; The tube side medium inlet of the preheater is positioned at the bottom of the tube array, and the tube side medium outlet is positioned at the top of the tube array; the tube side of the preheater is a straight tube or a U-shaped tube.
2. The method of claim 1, wherein the water after completion of the reactor wet oxidation reaction comprises 20% brine, excess oxygen, catalyst, and hydrochloric acid.
3. The method of claim 2, wherein the catalyst is a copper ion-containing catalyst.
4. The method of claim 1 to 3, wherein the reactor further comprises elements required for catalyzing the wet oxidation reaction, including but not limited to one or more selected from the group consisting of an inlet unit, an outlet unit, a feed unit, a discharge unit, and a meter unit.
5. A method according to any one of claims 1 to 3, wherein the treatment system further comprises a wastewater storage unit located upstream of the multistage centrifugal pump.
6. A method according to any of claims 1-3, wherein the treatment system further comprises a steam delivery unit upstream of the heater, the steam delivery unit being connected to the heater.
7. A method according to any of claims 1-3, wherein the treatment system further comprises a flash tank downstream of the heater, an inlet of the flash tank being connected to a condensate outlet of the heater.
8. The method according to claim 1, wherein the operating temperature of the reactor is between 150 and 300 ℃, and the pressure of the reactor is between 4 and 7mpa; And/or, during the catalytic wet oxidation reaction, the pH value of the wastewater is between 0.8 and 1.4; And/or the catalyst adopted by the catalytic wet oxidation reaction is a catalyst containing copper ions, and the content of the copper ions is 1000-3000 ppm.

Description

Wet oxidation wastewater treatment system and method Technical Field The invention belongs to the technical field of wastewater treatment, and particularly relates to a wet oxidation wastewater treatment system and a wet oxidation wastewater treatment method. Background At present, the high-pressure pump adopted in the traditional wet oxidation wastewater process is mostly a high-speed pump, and the rotating speed of the high-pressure pump is often over 6600 rpm. Because of the high rotational speed, the high speed pump can experience significant noise and vibration during operation and can increase the loss rate of the motor bearings. Therefore, not only is the cost required for maintaining the high-speed pump equipment increased, but also the stability and efficiency of the process are adversely affected. In addition, when a high-speed pump is used for treating a wastewater medium containing solid particles or high viscosity, the pumping effect is poor, and the conditions such as blockage and abrasion are easy to occur. Therefore, in the case of the conventional wet oxidation wastewater process, there is an urgent need to find a solution that is more efficient, stable and capable of reducing maintenance costs in terms of the type of high-pressure pump. The multistage centrifugal pump is formed by integrating more than two centrifugal pumps with the same function, and the medium pressure relief port of the first stage is communicated with the inlet of the second stage in the fluid channel structure, and the medium pressure relief port of the second stage is communicated with the inlet of the third stage, so that the multistage centrifugal pump is formed by the mechanism connected in series. The multistage centrifugal pump consists of a plurality of impellers, guide vanes (or volutes), pump shafts, balancing devices (such as balancing discs/drums), sealing rings and pump housings (segmented or split). Each impeller is arranged on the same shaft, and when liquid flows through the impellers of each stage in sequence, energy is overlapped step by step. Disclosure of Invention In order to solve the technical problems, the invention provides a wet oxidation wastewater treatment system, which comprises a multistage centrifugal pump; A preheater located downstream of the multistage centrifugal pump; A heater downstream of the preheater; And a reactor downstream of the heater. According to an embodiment of the invention, the multistage centrifugal pump employs 10 stages of impellers. In some embodiments, the motor of the multistage centrifugal pump adjusts the rotational speed by frequency up-conversion. For example, the rotational speed of the multistage centrifugal pump is 1400-2980 rpm, such as 1400rpm, 1500rpm, 1800rpm, 2000rpm, 2500rpm or 2980rpm. In some embodiments, the multistage centrifugal pump comprises a multistage impeller and a pump body, wherein the pump body comprises a suction section, a discharge section and a pump shaft, 5 impellers are respectively arranged in the suction section and the discharge section, the impellers are all arranged on the pump shaft, two adjacent impellers are fixed and loose-proof through screws, a partition plate is arranged between the two adjacent impellers of the suction section and the discharge section, and a fifth-stage impeller of the suction section and a first-stage impeller of the discharge section are communicated through a balance pipe along the flow direction of wastewater. In some embodiments, the impellers of the suction section and the discharge section are in opposite directions. The waste water after forward pressurization by the 5-stage impeller of the suction section is conveyed to the tail impeller of the discharge section by a balance pipe for further pressurization (namely, the pressurization mode of the discharge section is opposite to the forward pressurization acting force of the suction section), and finally flows out from the fifth-stage impeller of the discharge section. In some embodiments, the baffle is provided with a return aperture. The baffle of the discharge section and the suction section is provided with a reflow hole, and the problem that the discharge section is blocked by equipment due to pressure blocking of an outlet (similar to a safety valve) can be solved by utilizing the reflow hole. In some embodiments, the suction section is provided with a fluid inlet. In some embodiments, the discharge section is provided with a fluid outlet. In some embodiments, seals are provided at each end of the pump shaft. The existing multistage pump has the defects that the pump is damaged due to overlarge flow rate in the use process, and the like. According to an embodiment of the invention, the preheater is a tube array heat exchanger. In some embodiments, the tube side medium of the preheater is wastewater pressurized by a multistage centrifugal pump. For example, the wastewater contains 20% brine, 4000-5000 ppm organic matter, excessive oxyge