System for treating sludge drying flue gas based on hydrodynamic cavitation

Abstract

The utility model relates to a system for treating sludge drying flue gas based on hydrodynamic cavitation. The system comprises cyclone dust removal equipment, a centrifugal fan, spray washing equipment, hydrodynamic cavitation equipment, a gas-liquid separator and an activated carbon adsorber which are connected in sequence, one end, far away from the spraying and washing equipment, of the liquid discharging pipeline is connected with the water tank, an inlet of the filtering equipment is provided with a first pipeline connected with the water tank, an outlet of the filtering equipment is provided with a second pipeline connected with the reaction liquid storage tank, and an outlet of the reaction liquid storage tank is provided with a third pipeline; a delivery pump is arranged at one end, far away from the reaction liquid storage tank, of the third pipeline, a fourth pipeline connected with the hydrodynamic cavitation equipment is arranged at an outlet of the delivery pump, and the ozone generator is connected with the fourth pipeline through a fifth pipeline. The ozone is coupled in the hydrodynamic cavitation section, so that the mass transfer effect of the ozone can be enhanced, the oxidation effect of the ozone is further enhanced, and the effects of short reaction period, high stability, low cost and high efficiency are achieved.

Description

Technical Field

[0001] The present application relates to a flue gas treatment system, and more particularly to a system for treating sludge drying flue gas based on hydraulic cavitation. Background Art

[0002] Oily sludge often contains 10-30% oil and gas resources, in addition to aromatic hydrocarbons, which are hazardous wastes and need to be harmlessly treated before they can be used as resources or properly stored. At present, there are two main methods for treating oily sludge: direct incineration and high-temperature pyrolysis. Regardless of which method is used, the sludge drying mixed gas contains flue gas from the heat source, water vapor from sludge evaporation, and various gases released by the sludge.

[0003] The temperature of sludge drying tail gas is relatively high, and the tail gas treatment process first needs to cool the flue gas. Generally, cyclone dust removal, condensation cooling, water cyclone spraying and other devices are set up, and they are selected according to the degree of product drying. In addition, sludge drying flue gas is a pungent odor, mainly a complex mixed gas of various inorganic and organic components; organic compounds are mainly: low molecular fatty acids, amines, aldehydes, ketones, ethers, halogenated hydrocarbons, and aliphatic, aromatic, heterocyclic nitrogen or sulfide; inorganic compounds are mainly: ammonia (NH3), phosphine (PH3), hydrogen sulfide (H2S). Therefore, in view of the high temperature and complex composition of sludge drying flue gas, it is necessary to remove dust, cool down and deodorize the tail gas after drying while the sludge is thermally dried.

[0004] Sludge drying flue gas treatment technologies mainly include activated carbon adsorption, solvent absorption, condensation method, catalytic combustion, microbial degradation and advanced oxidation technologies such as low-temperature plasma and photocatalysis. However, due to their own limitations and the complexity and diversity of dried flue gas, these technologies have complex treatment processes, high costs and operating expenses, and are difficult to remove odor and organic matter economically and permanently. In addition, the current sludge drying flue gas cooling process has the problems of large water demand, high energy consumption, and large land occupation. Therefore, it is urgent to develop a system that is economical, convenient, simple to operate, and quickly and efficiently degrades organic matter. Utility Model Content

[0005] In order to improve the problems of complex sludge drying flue gas treatment process, low treatment efficiency and cooling process, the present application provides a system for treating sludge drying flue gas based on hydraulic cavitation.

[0006] The present application provides a system for treating sludge drying flue gas based on hydraulic cavitation, which adopts the following technical solution:

[0007] A system for treating sludge drying flue gas based on hydraulic cavitation, comprising a cyclone dust removal device, a centrifugal fan, a spray washing device, a hydraulic cavitation device, a gas-liquid separator and an activated carbon adsorber connected in sequence, wherein the outlet of the spray washing device is provided with a drainage pipeline, the hydraulic cavitation device and the gas-liquid separator are both provided with a return pipe, and the two return pipes are both connected to the spray washing device;

[0008] It also includes a water tank, a filtering device, a reaction liquid storage tank and an ozone generator. The end of the drainage pipeline away from the spray washing device is connected to the water tank. The inlet of the filtering device is provided with a first pipe connected to the water tank. The outlet of the filtering device is provided with a second pipe connected to the reaction liquid storage tank. The outlet of the reaction liquid storage tank is provided with a third pipe. The end of the third pipe away from the reaction liquid storage tank is provided with a delivery pump. The outlet of the delivery pump is provided with a fourth pipe connected to the hydrodynamic cavitation device. The ozone generator is connected to the fourth pipe through a fifth pipe.

[0009] In a specific implementation scheme, the spray washing equipment includes a primary spray washing equipment and a secondary spray washing equipment, the inlets of the primary spray washing equipment and the secondary spray washing equipment are both provided with liquid inlet pipes, and the reflux pipe and the two liquid inlet pipes are connected by a tee pipe.

[0010] In a specific embodiment, the hydrodynamic cavitation device is one or more connected in parallel.

[0011] In a specific embodiment, the hydrodynamic cavitation device is one or a combination of a porous plate type and a venturi tube type.

[0012] In a specific embodiment, the filter element of the filtering device is a metal mesh filter element, a ceramic membrane filter element, or a mixture thereof.

[0013] In summary, the present application includes at least one of the following beneficial technical effects:

[0014] 1. Use hydraulic cavitation equipment to inhale gas and cause liquid cavitation at the same time. The high-speed micro-jet, implosion force and shear force formed at the moment of cavitation bubble collapse will shear the gas, generating a large number of gas-filled microbubbles. Countless tiny gas-filled microbubbles further capture organic pollutants in the flue gas through adsorption and absorption. The organic pollutants are then oxidized and degraded by the high-potential oxidizing substances such as OH, OOH and H2O2 produced by water ionization under the high temperature and high pressure conditions at the moment of cavitation collapse, or thermally decomposed. On the other hand, the huge implosion force and shear force generated at the moment of cavitation collapse will also destroy the molecular bonds of macromolecular organic matter to achieve the purpose of degrading organic pollutants.

[0015] 2. Utilize hydraulic cavitation to couple ozone, and strengthen ozone mass transfer through the micro-jet effect formed by the hydraulic cavitation effect. At the same time, pressurized dissolution promotes heat and mass transfer and enhances ozone oxidation, greatly improving ozone utilization. Utilize hydraulic cavitation to enhance OH production. OH free radicals with extremely strong oxidation ability deeply oxidize and degrade large molecular toxic organic matter in dry flue gas through electron transfer and bond breaking between organic matter. It has the advantages of short reaction cycle, strong stability, low cost and high efficiency.

[0016] 3. The coupling of hydrodynamic cavitation and ozone oxidation can combine with hydrophobic oil substances, thereby effectively capturing oil pollutants in flue gas and improving the removal efficiency of macromolecular oil organic matter in flue gas from oily sludge drying;

[0017] 4. Two-stage spray washing is used to cool the flue gas, remove dust in the flue gas, and simultaneously react to remove H2S, NH3, etc. in the flue gas; in addition, part of the odor and organic pollutants in the flue gas will be absorbed by the spray liquid and discharged into the intermediate water tank with the sewage. The sewage is filtered to remove the waste residue and enters the reaction liquid storage tank, and enters the hydraulic cavitation equipment together with the reaction liquid. The reaction liquid serves as a medium for capturing organic pollutants in the flue gas. After being degraded and removed by the cavitation reaction, the organic pollutants are discharged into the two-stage spray washing equipment as a supplementary spray water for recycling, achieving the dual purposes of wastewater treatment and supplementary spray liquid, saving water resources and recycling;

[0018] 5. This system has a simple process, deeply and efficiently degrades organic matter, has a high removal rate, is easy to operate, and can recycle wastewater, reducing treatment costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of a system for treating sludge drying flue gas based on hydraulic cavitation in an embodiment of the present application. DETAILED DESCRIPTION

[0020] The following is combined with Figure 1 This application is described in further detail.

[0021] The embodiment of the present application discloses a system for treating sludge drying flue gas based on hydraulic cavitation.

[0022] Reference Figure 1 A system for treating sludge drying flue gas based on hydraulic cavitation includes a cyclone dust removal device, a centrifugal fan, a spray washing device, a hydraulic cavitation device, a gas-liquid separator and an activated carbon adsorber. The cyclone dust removal device, the centrifugal fan, the first-level spray washing device, the second-level spray washing device, the hydraulic cavitation device, the gas-liquid separator and the activated carbon adsorber are connected end to end through a pipeline.

[0023] The spray washing equipment includes a primary spray washing equipment and a secondary spray washing equipment. In this embodiment, both the primary spray washing equipment and the secondary spray washing equipment are washing towers, and the spray liquids of both are one or a mixture of tap water, dilute acid aqueous solution, dilute alkali aqueous solution, and surfactant aqueous solution. The hydrodynamic cavitation equipment is one or more in parallel. The type of the hydrodynamic cavitation equipment is one or a combination of a porous plate type and a venturi tube type.

[0024] In this embodiment, the working principle of the hydraulic cavitation device is that when water or solution is transported through the hydraulic cavitation device by a high-pressure pump, the pressure will gradually decrease, and the lowest pressure will be formed at the throttling and contraction part of the cavitator, such as the small holes of the porous plate or the throat of the venturi tube, and the flue gas will be sucked in. Due to the impact of gas and the shearing effect of water flow, a large number of tiny cavitation bubbles are formed in the low-pressure area, and the cavitation bubbles containing dried flue gas are compressed and flow out of the cavitator, and then aggregate and grow, thereby producing a cavitation effect. Under the action of the cavitation effect, water molecules will decompose to form ·OH, ·OOH, H2O2 high-potential oxidizing substances to oxidize and degrade organic matter or cause it to thermally decompose.

[0025] The porous plate type hydraulic cavitation equipment refers to the equipment with multiple small holes in the orifice plate. When the fluid flows through these small holes, a cavitation effect is formed, thereby achieving the degradation and removal of organic matter. The venturi tube type hydraulic cavitation equipment refers to the equipment with a venturi tube ejector inside, which realizes the cavitation effect when the high-speed liquid flows through the throat of the venturi tube, and can also be used for the degradation and removal of organic matter.

[0026] In this embodiment, the activated carbon adsorber is an activated carbon filter having an adsorption function, and the cyclone dust removal device is a cyclone dust collector.

[0027] In the present application, the ozone oxidation method can be used to directly oxidize the treated material with ozone, or to oxidize the treated material with ·OH generated by its decomposition. However, when ozone is used to treat sewage, it is often difficult to dissolve into the aqueous solution quickly due to its poor mass transfer effect with the aqueous solution. Hydrodynamic cavitation is to use a throttling device to reduce the fluid pressure at the throttling point to below the saturated vapor pressure and generate cavitation bubbles. After the fluid flows through the throttling device, the cavitation bubbles collapse as the pressure rises, generating high-speed microjets, shock waves, shear forces, implosion forces, and extremely short strong pressure pulses to form high temperature and high pressure around the bubbles and generate ·OH, which acts on organic matter, destroys the molecular bonds of organic matter or pyrolyzes it. It is an oxidation technology without secondary pollution, with the characteristics of high efficiency and energy saving, simple operation, and low cost. Its unique generation method will make the fluid have high turbulence intensity, so coupling ozone in the hydraulic cavitation section can enhance the mass transfer effect of ozone, thereby enhancing the oxidation effect of ozone.

[0028] A system for treating sludge drying flue gas based on hydraulic cavitation, further comprising a water tank, a filtering device, a reaction liquid storage tank and an ozone generator; in the present embodiment, the solution in the reaction liquid storage tank is one of a dilute alkali aqueous solution and an H2O2 aqueous solution; the filtering device adopts a single-core precision filter; the filter element of the filtering device is one of a metal mesh filter element and a ceramic membrane filter element or a mixture; ozone is added through an ozone generator to control the ozone concentration to be greater than 100 mg / L.

[0029] The outlets of the primary spray washing equipment and the secondary spray washing equipment are both provided with a drainage pipeline, the other end of the drainage pipeline is connected to the water tank, the outlet of the water tank is connected to the inlet of the filter device through a first pipeline, the outlet of the filter device is provided with a second pipeline and the outlet of the reaction liquid storage tank is provided with a third pipeline, the outlet of the reaction liquid storage tank is provided with a delivery pump at one end away from the reaction liquid storage tank, the delivery pump is a high-pressure pump in this embodiment, and the material of the high-pressure pump is one of 304, 316, biaxial steel, and polytetrafluoroethylene. The outlet of the delivery pump is provided with a fourth pipeline connected to the hydraulic cavitation device, and the ozone generator is connected to the fourth pipeline through a fifth pipeline.

[0030] The hydraulic cavitation equipment and the gas-liquid separator are both provided with reflux pipes, which are connected by a main pipe. The inlets of the first-stage spray washing equipment and the second-stage spray washing equipment are both provided with liquid inlet pipes, which are connected by a tee pipe to the main pipe and the two liquid inlet pipes.

[0031] The implementation principle of an oily sludge drying flue gas treatment system in the embodiment of the present application is: using a centrifugal fan for suction, the flue gas is first input into a cyclone dust removal device along a pipeline to remove dust from the flue gas, and then transported to a primary spray washing device and a secondary spray washing device to spray and wash the flue gas for dust removal and cooling, and then enters a hydraulic cavitation device to degrade and remove pollutants in the flue gas; the waste water after the flue gas is sprayed is transported to an intermediate water tank along a drainage pipeline, and then enters a filter device along a first pipeline for filtration, and then enters a reaction liquid storage tank along a second pipeline, and a delivery pump transports the liquid in the reaction liquid storage tank to the hydraulic cavitation device along a third pipeline and a fourth pipeline, and an ozone generator generates ozone, and passes through the first The fifth pipeline is input into the fourth pipeline, and the liquid carrying ozone can then enter the hydraulic cavitation generator at the same time, thereby realizing the coupling of hydraulic cavitation and ozone oxidation. After the liquid enters the hydraulic cavitation equipment to produce cavitation effect to treat the gas, the gas and liquid are separated by the gas-liquid separator. The waste liquid discharged from the hydraulic cavitation equipment and the gas-liquid separator is transported to the liquid inlet pipe along the reflux pipe and the main pipe, so that it can be transported to the first-level spray equipment and the second-level spray equipment to spray the flue gas for dust removal and cooling, so that water can be recycled and water resources can be saved; the gas separated by the gas-liquid separator is finally further adsorbed and removed by the activated carbon adsorber before being discharged, so that the flue gas can be treated to meet the emission standards.

[0032] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A system for treating sludge drying flue gas based on hydraulic cavitation, characterized in that: It includes a cyclone dust removal device, a centrifugal fan, a spray washing device, a hydraulic cavitation device, a gas-liquid separator and an activated carbon adsorber connected in sequence, wherein the outlet of the spray washing device is provided with a liquid discharge pipeline, and the hydraulic cavitation device and the gas-liquid separator are both provided with a return pipe, and the two return pipes are both connected to the spray washing device; It also includes a water tank, a filtering device, a reaction liquid storage tank and an ozone generator. The end of the drainage pipeline away from the spray washing device is connected to the water tank. The inlet of the filtering device is provided with a first pipe connected to the water tank. The outlet of the filtering device is provided with a second pipe connected to the reaction liquid storage tank. The outlet of the reaction liquid storage tank is provided with a third pipe. The end of the third pipe away from the reaction liquid storage tank is provided with a delivery pump. The outlet of the delivery pump is provided with a fourth pipe connected to the hydrodynamic cavitation device. The ozone generator is connected to the fourth pipe through a fifth pipe.

2. A system for treating sludge drying flue gas based on hydraulic cavitation according to claim 1, characterized in that: The spray washing equipment comprises a primary spray washing equipment and a secondary spray washing equipment. The inlets of the primary spray washing equipment and the secondary spray washing equipment are both provided with liquid inlet pipes. The reflux pipe and the two liquid inlet pipes are connected via a tee pipe.

3. The system for treating sludge drying flue gas based on hydraulic cavitation according to claim 1, characterized in that: The hydrodynamic cavitation equipment is one or more connected in parallel.

4. The system for treating sludge drying flue gas based on hydraulic cavitation according to claim 1, characterized in that: The hydrodynamic cavitation equipment is one or a combination of a porous plate type and a venturi tube type.

5. The system for treating sludge drying flue gas based on hydraulic cavitation according to claim 1, characterized in that: The filter element of the filtering device is a metal mesh filter element, a ceramic membrane filter element or a mixture thereof.

Images