A nano-scale alloy filter element boiler drainage recovery system

Abstract

The invention discloses a nanometer-level alloy filter element boiler continuous drainage recovery system, which belongs to the field of continuous drainage treatment, and comprises an atomizing device and a steam purification device. A continuous drainage inlet pipe is arranged on one side of the atomizing device, and the atomizing device and the steam purification device are connected through the steam inlet pipe; the steam purification device comprises a shell and an alloy filter element arranged in the shell, and the alloy filter element production process comprises the following steps: selecting powders of 66-68% iron, 10% manganese, 2% nickel, 10% titanium, 5% chromium, 3% carbon, and 2-4% vanadium; mixing the powders, extruding and shaping them through a mold; sintering the shaped powder into a shape; cooling the sintered filter screen; and producing an alloy filter element, which is corrosion-resistant, high-temperature-resistant, and has high mechanical strength, greatly improving the service life of the filter element, and at the same time, the alloy filter element has a good regeneration effect.

Description

Technical Field

[0001] The invention belongs to the technical field of continuous drainage treatment, and in particular relates to a nano-level alloy filter element boiler continuous drainage recovery system. Background Art

[0002] The boiler continuous drainage recovery system is mainly used to recover the high-temperature, high-pressure wastewater generated by the boiler during the continuous drainage process. Through a series of treatment and utilization methods, the waste heat and wastewater are utilized as resources, which not only improves the energy utilization efficiency but also reduces environmental pollution. The purpose of drainage is to protect the quality of boiler water so that the boiler can operate safely and stably for a long time. However, directly discharging continuous drainage wastewater and fixed drainage wastewater not only loses heat and affects the boiler efficiency, but also causes thermal pollution to the environment.

[0003] The existing continuous drainage recovery system (such as CN 218523550 U, a continuous drainage waste heat recovery system) uses a polymer filter element in the filter tube, and uses a polymer filter element such as PE, PP filter element, etc. for filtering. This kind of filter element has the following problems: Temperature influence: After working in a high temperature environment for a long time, the PE and PP materials will gradually age, become fragile, and easily break or deform. This will cause the filtering effect of the filter element to decrease, or even completely fail. The thermal stability of PE and PP is relatively poor. When the temperature exceeds its tolerance range, the material may melt or produce harmful substances. This will not only affect the service life of the filter element, but may also cause pollution to the system. Insufficient chemical stability: Although PE and PP materials show good stability to many chemical substances, they may swell, dissolve or degrade to certain organic solvents, such as alcohols, ketones, esters, etc. When these organic solvents are contained in the continuous drainage, the filtering effect of the PE and PP filter elements will be greatly reduced, or even dissolved, causing the system to fail;

[0004] If alloy filter elements are used for replacement, their strength and corrosion resistance will be improved. However, their corrosion resistance is not very ideal under steam filtration. Existing alloy metal filter elements are mainly made of carbon, manganese, phosphorus, sulfur, silicon, chromium, nickel and iron, and most of their corrosion resistance is at Class B or Class C (Class A: corrosion rate below 0.127mm / year, Class B: corrosion rate below 0.127-1.27 / year is usable, Class C: corrosion rate above 1.27mm / year is unusable). It is impossible to reach Class A for complete corrosion resistance, which shortens the overall service life of the boiler and wastewater recovery system. Summary of the invention

[0005] The purpose of the present invention is to provide a nano-scale alloy filter element boiler continuous drainage recovery system to solve the problem of short filtering service life of the existing continuous drainage filter element.

[0006] To achieve the above object, the present invention provides the following technical solution: a nano-scale alloy filter element boiler continuous drainage recovery system, comprising an atomizing device and a steam purification device, a continuous drainage inlet pipe is arranged on one side of the atomizing device, and the atomizing device and the steam purification device are connected through the steam inlet pipe;

[0007] The steam purification device comprises a housing and an alloy filter element arranged in the housing, and the alloy filter element production process comprises the following steps:

[0008] Step S1: powder selection; select powder containing 66-68% iron, 10% manganese, 2% nickel, 10% titanium, 5% chromium, 3% carbon and 2-4% vanadium;

[0009] Step S2: mixing the powders of step S1 and extruding them through a mold to shape them;

[0010] Step S3: sintering the powder formed in step S2;

[0011] Step S4: Cooling the filter screen fired in step S3.

[0012] Furthermore, a steam inlet pipe and a steam outlet pipe are respectively installed on both sides of the shell, and pressure detectors are installed on the steam inlet pipe and the steam outlet pipe.

[0013] Furthermore, a flushing water inlet pipe is installed at the top of the steam purification shell, and a flushing water drain pipe is installed at the bottom of the steam purification shell.

[0014] Furthermore, a high-temperature air inlet pipe is provided on one side of the atomization device.

[0015] Furthermore, the specific operations of step S2 are as follows:

[0016] Choose a mold with a micropore diameter of 0.22-100μm and a porosity of 35-45%;

[0017] Pour the mixed powder in step S1 into a mold;

[0018] The extrusion equipment was extruded at an internal temperature of 375-450°C, an extrusion ratio of 10:1, an extrusion speed of 22 mm / s, a pressure of 900-2000 MPa, and a heat preservation time of 2 hours.

[0019] Furthermore, the specific operations of step S3 are as follows:

[0020] The filter element extruded and shaped in step S2 is placed in a sintering furnace, the air in the sintering chamber and the gas attached to the compact are evacuated, and then the pressure is reduced to below 1.3×10^-2 Pa by secondary vacuuming;

[0021] The heating furnace is heated at a heating rate of 20-30°C / min to 400-500°C and maintained in this temperature range for 1-2 hours;

[0022] The sintering temperature is controlled within the range of 1200~1500℃ and the calcination time is 4-8h.

[0023] Furthermore, the specific operations of step S4 are as follows:

[0024] Move the filter element fired in step S3 to a designated position for slow natural cooling to below 800°C. In the 800°C-500°C stage, the cooling rate is 50-80°C per hour. When the temperature drops below 500°C, cool it naturally to room temperature.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The nano-scale alloy filter element boiler drainage recovery system adopts an alloy filter element of iron, manganese, nickel, titanium, chromium, carbon and vanadium. The alloy filter element is corrosion-resistant, high-temperature-resistant and has high mechanical strength, which greatly increases the service life of the alloy filter element. At the same time, the alloy filter element has a good regeneration effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the nano-alloy filter element boiler wastewater recovery system.

[0028] In the figure: 10, atomizing device; 101, drainage inlet pipe; 102, high-temperature air inlet pipe; 20, steam purification device; 201, steam inlet pipe; 202, steam discharge pipe; 203, pressure detector; 204, flushing water inlet pipe; 205, flushing water discharge pipe; 210, housing; 220, alloy filter element. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with the embodiments.

[0030] The following examples are used to illustrate the present invention, but they cannot be used to limit the scope of protection of the present invention. The conditions in the examples can be further adjusted according to specific conditions. Simple improvements to the method of the present invention under the premise of the concept of the present invention belong to the scope of protection claimed in the present invention.

[0031] See also Figure 1 The present invention provides a nano-scale alloy filter element boiler continuous drainage recovery system, comprising an atomizing device 10 and a steam purification device 20, a continuous drainage inlet pipe 101 is arranged on one side of the atomizing device 10, and the atomizing device 10 and the steam purification device 20 can be connected through the steam inlet pipe 201;

[0032] A high-temperature air inlet pipe 102 is provided on one side of the atomizing device 10 for gasifying the discharged water.

[0033] The steam purification device 20 includes a steam purification housing 210, an alloy filter element 220 is arranged inside the housing 210, a steam inlet pipe 201 and a steam outlet pipe 202 are respectively installed on both sides of the housing 210, and a pressure detector 203 is installed on the steam inlet pipe 201 and the steam outlet pipe 202; the pressure detector 203 is installed on the steam inlet pipe and the steam outlet pipe, and is used to monitor the pressure change of the steam in real time. Through the pressure detector 203, the pressure loss of the steam during the purification process can be understood, so as to judge the filtering effect of the alloy filter element 220 and the operating status of the device. If the pressure is found to be abnormal, the steam flow rate can be adjusted in time or the filter element can be replaced to ensure the normal operation of the steam purification device 20.

[0034] A flushing water inlet pipe 204 is installed on the top of the steam purification shell 210, and a flushing water drain pipe 205 is installed on the bottom of the steam purification shell 210. Flushing water is introduced through the flushing water inlet pipe 204 to flush the alloy filter element 220, thereby improving the service life of the alloy filter element 220.

[0035] The alloy filter element 220 is made of iron, manganese, nickel, titanium, chromium, carbon and vanadium alloy, with a porosity of 25-45% and a filtration accuracy of 0.22-100μm;

[0036] The alloy filter element has excellent corrosion resistance and can be used for filtering in strong alkali and strong acid media.

[0037] Alloy filter elements can withstand high temperatures up to 900°C and are suitable for high-temperature working environments. However, the temperature difference resistance of polymer filter elements generally does not exceed 50°C. If the temperature exceeds 50°C, the support and filter membrane will change, and the filtration accuracy will deviate greatly. Even PTFE filter elements will deform and age if they work for a long time in an operating environment above 120°C and with an external pressure of 0.2MPa.

[0038] Alloy filter element 220 has super strong mechanical properties and can be used under high pressure. When the external pressure of other polymer filter elements exceeds 0.5MPa, the pore size of the filter will change or even be punctured.

[0039] It has good regeneration effect, which depends on its excellent corrosion resistance, high temperature resistance and high strength performance. There are two regeneration methods: physical regeneration method and chemical regeneration method:

[0040] Physical regeneration method:

[0041] (1) Pure water backwash

[0042] (2) Steam backwash

[0043] (3) Ultrasonic cleaning

[0044] Chemical treatment:

[0045] (1) Alkaline washing

[0046] (2) Pickling

[0047] Among the above treatment methods, chemical treatment and ultrasonic cleaning are the best, with low attenuation of filtration efficiency. Since the alloy filter element is well regenerated, it can be used for fluids with viscous viscosity.

[0048] Applicable to high temperature gas filtration.

[0049] The use process of the present invention is as follows: the continuous drainage water is atomized by the atomizing device, and then the high-temperature air inlet pipe 102 on the left side of the atomizing device 10 injects gas from left to right. The atomized continuous drainage water is gasified and enters the steam purification device through the steam inlet pipe together with the injected gas, and is discharged from the system after being filtered by the alloy filter element 220 to obtain pure steam.

[0050] The production process of alloy filter element 220 includes the following steps: powder selection, extrusion shaping, sintering shaping, and cooling.

[0051] Step S1: powder selection;

[0052] Select powdered iron 66~68%, manganese 10%, nickel 2%, titanium 10%, chromium 5%, carbon 3%, and vanadium 2~4%.

[0053] Iron (Fe): 66~68% - Iron is the main component of the alloy, providing basic physical and chemical properties.

[0054] Manganese (Mn): 10% - Manganese is commonly used to increase the strength, hardness and wear resistance of alloys.

[0055] Nickel (Ni): 2% - Nickel increases the corrosion resistance of the alloy and helps improve its mechanical properties.

[0056] Titanium (Ti): 10% - Titanium is a lightweight and corrosion-resistant metal that improves the corrosion resistance of the alloy.

[0057] Chromium (Cr): 5% - Chromium is a commonly used alloying element that enhances the corrosion resistance, hardness and wear resistance of the alloy.

[0058] Carbon (C): 3% - Carbon is a key element in steel and many alloys, adding hardness and strength.

[0059] Vanadium (V): 2~4% - Vanadium can improve the strength and toughness of the alloy.

[0060] Step S2: extrusion shaping;

[0061] A: Choose a mold with a micropore diameter of 0.22-100μm and a porosity of 35-45%;

[0062] B: pouring the mixed powder in step S1 into a mold;

[0063] C: The extrusion equipment is extruded according to the internal temperature of 375-450°C, the extrusion ratio of 10:1, the extrusion speed of 22mm / s, the pressure of 900-2000Mpa, and the insulation time of 2 hours.

[0064] Extrusion temperature: The extrusion temperature should be between 375℃ and 450℃. The extrusion temperature can improve the fluidity of the material and is conducive to the densification of the material.

[0065] Extrusion ratio: high-quality extruded billets can be obtained at an extrusion ratio of 10:1. The selection of extrusion ratio has an important influence on the microstructure and performance of the alloy filter element. Too low an extrusion ratio may cause the fine powder to not be completely deformed, affecting mutual bonding.

[0066] Extrusion speed: The extrusion speed is 22mm / s. The selection of extrusion speed should comprehensively consider the deformation capacity of the material and production efficiency.

[0067] Insulation time: The insulation time of the package and the mold at the extrusion temperature is usually 2 hours to ensure that the alloy powder is fully heated. The length of the insulation time has an important influence on the uniformity and density of the alloy.

[0068] Pressure: The lower limit pressure (900Mpa) is usually sufficient to form initial contact and bonding between powder particles.

[0069] Upper limit pressure (2000Mpa): This pressure level is relatively high, which can ensure close bonding between powder particles, thereby improving the density and performance of the product. However, too high a pressure may increase the risk of wear and damage to the mold, and may also cause stress concentration and defects inside the material.

[0070] Maintain shape stability: The alloy after extrusion is stable in shape and will not be severely deformed during the firing process.

[0071] Improve sintering efficiency: After extrusion, the powder particles have initial contact and bonding, which makes the diffusion and bonding between the particles easier during the firing process, thereby improving the sintering efficiency.

[0072] Improved microstructure: Through extrusion, the microstructure of the alloy, such as particle size, distribution and orientation, can be controlled, which in turn affects the properties of the alloy.

[0073] Reduce energy consumption: Extrusion and shaping first can make the powder particles more densely arranged before firing, reducing the escape of gas and the formation of pores during firing, thereby reducing energy consumption.

[0074] Step S3: sintering and molding;

[0075] A: Place the filter element extruded and shaped in step S2 into the sintering furnace and first perform a vacuum operation to remove the air in the sintering chamber and the gas attached to the compact. The second stage of vacuuming reduces the pressure to below 1.3×10^-2 Pa to ensure the smooth progress of the sintering process.

[0076] B: The heating furnace is electrically heated at an appropriate heating rate (20-30℃ / min) to 400-500℃ and maintained in this temperature range for 1-2 hours.

[0077] C: Fill with argon and heat to sintering temperature

[0078] In order to sinter under a protective atmosphere, the sintering chamber is filled with argon, and the sintering temperature is controlled within the range of 1200~1500℃. The calcination time is 4-8h. Too high a temperature may cause the product to soften and deform, while too low a temperature may prolong the sintering time and reduce equipment utilization.

[0079] Step S4: Cooling

[0080] After calcination, the equipment should be slowly cooled naturally to 800℃ at a designated location. In the 800℃-500℃ stage, the hourly cooling rate can be appropriately slowed down to about 50-80℃ to further reduce thermal stress. When the temperature drops below 500℃, it can be allowed to cool naturally to room temperature. During the entire cooling process, the surface temperature should be monitored regularly and the cooling rate should be adjusted as needed.

[0081] If forced cooling is used at this time, such as sudden cooling or rapid cooling, the temperature difference between the inside and outside of the material will increase sharply, which may cause the thermal stress to exceed the material's tolerance limit, thereby causing cracks or deformation. The natural cooling process is relatively slow, which helps to gradually release the thermal stress inside the material and reduce cracks or deformation problems caused by stress concentration.

[0082] Embodiment 1:

[0083] (1) Select powdered iron 68%, manganese 10%, nickel 2%, titanium 10%, chromium 5%, carbon 3%, and vanadium 2%.

[0084] (2) The upper powder is evenly filled into the mold, and the extrusion equipment is extruded at 450°C, extrusion ratio 10:1, extrusion speed 22mm / s, pressure 900Mpa, and insulation time 2 hours.

[0085] (3) Place the extruded filter element into a sintering furnace and evacuate the pressure to below 1.3×10^-2 Pa to ensure the smooth progress of the sintering process. The heating furnace is electrically heated at a heating rate of 30℃ / min to 500℃ and maintained at this temperature for 1 hour. Then, argon is filled and the temperature is continued to rise to 1500℃. The calcination time is 4h.

[0086] (4) After calcination, the temperature is lowered to 800°C, then lowered to 500°C at a rate of 80°C per hour, and then naturally cooled to room temperature to obtain a finished filter element A.

[0087] Embodiment 2:

[0088] (1) Select powdered iron 67%, manganese 10%, nickel 2%, titanium 10%, chromium 5%, carbon 3%, and vanadium 3%.

[0089] (2) The upper powder is evenly filled into the mold, and the extrusion equipment is used for extrusion molding at 400°C, extrusion ratio 10:1, extrusion speed 22mm / s, pressure 1500Mpa, and insulation time 2 hours.

[0090] (3) Place the extruded filter element into a sintering furnace and evacuate the pressure to below 1.3×10^-2 Pa to ensure the smooth progress of the sintering process. The heating furnace is electrically heated at a heating rate of 25℃ / min to 450℃ and maintained at this temperature for 1.5 hours. Then, argon is filled and the temperature is continued to rise to 1300℃. The calcination time is 6 hours.

[0091] (4) After calcination, the temperature is lowered to 800°C, then lowered to 500°C at 70°C per hour, and then naturally cooled to room temperature to obtain the finished filter element B.

[0092] Embodiment 3:

[0093] (1) Select powdered iron 68%, manganese 10%, nickel 2%, titanium 10%, chromium 5%, carbon 3%, and vanadium 2%.

[0094] (2) The upper powder is evenly filled into the mold, and the extrusion equipment is extruded at 375°C, extrusion ratio 10:1, extrusion speed 22mm / s, pressure 2000Mpa, and insulation time 2 hours.

[0095] (3) Place the extruded filter element into a sintering furnace and evacuate the pressure to below 1.3×10^-2 Pa to ensure the smooth progress of the sintering process. The heating furnace is electrically heated at a heating rate of 25℃ / min to 450℃ and maintained at this temperature for 2 hours. Then, argon is filled and the temperature is continued to rise to 1200℃. The calcination time is 8h.

[0096] (4) After calcination, the temperature is lowered to 800°C, then lowered to 500°C at a rate of 50°C per hour, and then naturally cooled to room temperature to obtain a finished filter element C.

[0097] Implementation 1-3 obtained filter A, filter B, filter C and the existing metal filter (C 0.08, Mn 2.0, P0.045, S 0.03, Si 1.0, Cr 18-20, Ni8-11 the rest is Fe) comparison shown in Table 1-3;

[0098] In Table 1, Grade A: corrosion rate below 0.127mm / year is completely corrosion-resistant; Grade B: corrosion rate below 0.127-1.27mm / year is usable; Grade C: corrosion rate above 1.27mm / year is unusable.

[0099] Corrosion resistance performance test comparison see Table 1: Table 1

[0100]

[0101] Table 1 continued

[0102]

[0103] Mechanical properties test comparison see Table 2:

[0104] Table 2

[0105]

[0106] See Table 3 for the comparison of regeneration performance test:

[0107] Table 3

[0108]

[0109] The above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the embodiments of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description, and these obvious changes or modifications derived from the spirit of the present invention are still within the scope of protection of the present invention.

Claims

1. A nano-grade alloy filter element boiler drainage recovery system, characterized by: It comprises an atomizing device (10) and a steam purification device (20), wherein a water discharge inlet pipe (101) is provided on one side of the atomizing device (10), and the atomizing device (10) and the steam purification device (20) are connected via the steam inlet pipe (201); The steam purification device (20) comprises a housing (210) and an alloy filter element (220) arranged in the housing (210), and a production process of the alloy filter element (220) comprises the following steps: Step S1: powder selection; select powder containing 66-68% iron, 10% manganese, 2% nickel, 10% titanium, 5% chromium, 3% carbon and 2-4% vanadium; Step S2: Select a mold with a micropore diameter of 0.22-100 μm and a porosity of 35-45%; Pour the mixed powder in step S1 into a mold; The extrusion equipment is extruded according to the internal temperature of 375-450°C, the extrusion ratio of 10:1, the extrusion speed of 22mm / s, the pressure of 900-2000Mpa, and the insulation time of 2 hours; Step S3: the filter element extruded and shaped in step S2 is placed in a sintering furnace, the air in the sintering chamber and the gas attached to the pressed block are evacuated, and then the pressure is reduced to below 1.3×10^-2 Pa by secondary vacuuming; The heating furnace is heated at a heating rate of 20-30°C / min to 400-500°C and maintained in this temperature range for 1-2 hours; Control the sintering temperature within the range of 1200~1500℃ and the calcination time is 4-8h; Step S4: Move the filter element fired in step S3 to a designated position for slow natural cooling to below 800°C. In the 800°C-500°C stage, the cooling rate is 50-80°C per hour. When the temperature drops below 500°C, cool it naturally to room temperature.

2. The nano-alloy filter element boiler drainage recovery system according to claim 1, characterized in that: A steam inlet pipe (201) and a steam outlet pipe (202) are respectively installed on both sides of the shell (210), and a pressure detector (203) is installed on both the steam inlet pipe (201) and the steam outlet pipe (202).

3. The nano-alloy filter element boiler drainage recovery system according to claim 1, characterized in that: A flushing water inlet pipe (204) is installed at the top of the steam purification housing (210), and a flushing water drain pipe (205) is installed at the bottom of the housing (210).

4. The nano-alloy filter element boiler drainage recovery system according to claim 1, characterized in that: A high-temperature air intake pipe (102) is provided on one side of the atomization device (10).

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