A boiler wastewater desalination and mixing device

Abstract

The present invention relates to a boiler wastewater desalination mixing device, in which saturated steam of the boiler is accelerated to generate vortex through a rotating accelerating tube, and is contacted with wastewater sprayed from an annular pipe at the rear section of the rotating accelerating tube and gasified (flash evaporated). The rotating accelerating tube increases the contact area between the steam medium and the wastewater, which is beneficial to improving the uniformity between the steam and the wastewater, and makes the wastewater gasified instantly. Then, the inorganic salt contained in the wastewater is crystallized on the adsorption filter and adsorbed on the adsorption filter, and the impurities in the wastewater are directly intercepted by the adsorption filter. The quality of the purified mixed steam can reach the quality of the original steam, and the boiler wastewater and impurities are effectively treated and reused, thereby realizing the "zero discharge" of boiler wastewater.

Description

Technical Field

[0001] The invention relates to boiler waste water treatment in the field of environmental protection, and in particular to a device for removing salt and impurities in boiler waste water and reusing the water. Background Art

[0002] "Industrial Boiler Water Quality Standard" GB / T1576-2018 stipulates the water quality standards for boiler feed water and boiler water. In order to ensure the quality of steam, it is necessary to continuously discharge wastewater from the boiler drum (water-steam boundary). These wastewaters contain impurities such as phosphates, calcium and magnesium ion deposits, and silica (dissolved solids). During boiler operation, the safety of the boiler and the quality of the steam produced are mainly guaranteed by controlling the water quality in the boiler.

[0003] At present, the common treatment method for boiler wastewater discharged from the boiler is to discharge it into an expansion tank, flash evaporate it in the expansion tank to become a mixture of steam and water, and the steam part is connected to the deaerator for utilization (for example, the utilization of the heat of boiler wastewater is generally not more than 15%). Most of them are directly discharged into sewage wells or ditches, and then discharged to sewage treatment plants through sewage pipe networks. Due to its high temperature and high salinity, it not only causes serious harm to the surrounding environment, but also causes a large amount of water resources and heat energy to be wasted, increasing the load of sewage treatment. Direct discharge causes a large amount of waste of high-quality water resources and thermal pollution problems. Summary of the invention

[0004] The purpose of the present invention is to provide a device for effectively treating boiler waste water and impurities and reusing them, thereby achieving "zero discharge" of boiler waste water.

[0005] In order to achieve the above object, the present invention is implemented by the following technical solutions:

[0006] A boiler wastewater desalination mixing device comprises a body, a steam inlet and a steam outlet at both ends of the body, and a wastewater inlet at a side end, wherein the body is provided with an expansion chamber connected to the steam inlet, an outlet chamber connected to the steam outlet, and a mixing chamber between the expansion chamber and the outlet chamber, wherein the expansion chamber and the mixing chamber are connected through a rotating acceleration tube, an adsorption filter for intercepting salt is provided between the mixing chamber and the outlet chamber, and the wastewater inlet is connected to the rotating acceleration tube through an annular pipe; steam enters from the steam inlet, enters the rotating acceleration tube after passing through the expansion chamber, and is accelerated by the rotating acceleration tube to generate a swirl, and the speed of the swirl is proportional to the flow rate of the steam, and the faster the flow rate, the faster the rotation speed. The steam contacts and gasifies (flash evaporates) the wastewater sprayed from the annular pipe at the rear section of the rotating acceleration tube, and since the steam medium passing through is in a rotating circulation state, the contact area between the steam medium and the wastewater is increased, which is conducive to improving the uniformity between the steam and the wastewater.

[0007] Preferably, the cross-section of the expansion chamber is larger than the cross-section of the pipe at the steam inlet, and a funnel-shaped baffle is provided at the connection with the rotating acceleration tube; the flow cross-section of the expansion chamber is larger than the flow cross-section of the air inlet, which can effectively reduce the flow rate of the steam, and the funnel-shaped baffle can reduce the impact of the steam entering the inlet on the subsequent equipment, while guiding the steam into the rotating acceleration tube.

[0008] Preferably, the rotating accelerating tube is provided with spiral grooves or spiral blades on the inner wall of the front section connected to the expansion chamber, so that the flow rate of the steam entering the rotating accelerating tube is accelerated and rotated.

[0009] Preferably, the rear end of the rotating accelerating tube is a smooth inner wall, and a plurality of nozzle holes are circumferentially arranged on the smooth inner wall. The annular pipeline and the rotating accelerating tube are connected through an atomizing nozzle installed on the nozzle hole. The mist wastewater sprayed by the atomizing nozzle is fully contacted and mixed with the rotating steam in the spiral channel, so that the wastewater is instantly evaporated into steam and merged into the mixing chamber.

[0010] Preferably, an orifice plate is provided at the outlet side of the rotating accelerating tube, and the orifice plate is composed of a plurality of orifice plates with flow holes. The function of the orifice plate is to protect the filter behind from being impacted by the medium with a high flow rate, thereby reducing the use effect or causing damage.

[0011] Preferably, the flow cross-section of the mixing chamber is larger than the cross-section of the rotating acceleration tube, and an inspection hole is provided on the upper side or the side; the inspection hole facilitates maintenance personnel to enter and exit the equipment for maintenance work, and is also convenient for replacing the internal adsorption filter and orifice plate.

[0012] Preferably, the adsorption filter is made of a nano-scale metal filter, which can effectively adsorb and retain salt in the mixed steam.

[0013] Preferably, the adsorption filter is composed of a plurality of filter screens.

[0014] Preferably, a pressure difference transmitter is provided on the upper side of the expansion chamber and the outlet chamber. When the adsorption filter is clogged due to excessive salt crystallization, the pressure difference at both ends will increase. When the set threshold is reached, a signal is sent out, the control system alarms and stops the equipment operation, reminding that the filter needs to be cleaned.

[0015] Preferably, the expansion chamber, mixing chamber and outlet chamber are each provided with a sewage outlet at the lower side and a cleaning water inlet at the upper side, and each sewage outlet is connected to a drainage pipe for discharging cleaned water and impurities.

[0016] The present invention accelerates the saturated steam of the boiler through a rotating accelerating tube to generate a swirl flow, and contacts and vaporizes (flash evaporates) the waste water sprayed from the annular pipe at the rear section of the rotating accelerating tube. The rotating accelerating tube increases the contact area between the steam medium and the waste water, which is beneficial to improving the uniformity between the steam and the waste water, and vaporizes the waste water instantly. The waste water then passes through an adsorption filter, so that the inorganic salts contained in the waste water form crystals on the adsorption filter and are adsorbed on the adsorption filter. At the same time, the impurities in the waste water are directly intercepted by the adsorption filter. The quality of the purified mixed steam can reach the quality of the original steam, and the boiler waste water and impurities are effectively treated and reused, thereby achieving "zero discharge" of boiler waste water. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the present invention;

[0018] Figure 2 is a perspective view of the mechanism of the present invention;

[0019] Figure 3 is a schematic diagram of a funnel-shaped baffle of the present invention;

[0020] Figure 4 is a schematic diagram of a rotating accelerator tube of the present invention;

[0021] Figure 5 It is a schematic diagram of the annular pipeline, atomizing nozzle and wastewater inlet of the present invention;

[0022] Figure 6 It is a schematic diagram of the structural relationship of the annular pipeline, the atomizing nozzle and the wastewater inlet when they are combined in the present invention;

[0023] Figure 7 It is a schematic diagram that the orifice plate of the present invention is composed of one or more pieces;

[0024] Figure 8 It is a schematic diagram showing that the adsorption filter screen of the present invention is composed of one or more blocks;

[0025] Fig. 9 It is a schematic diagram of installing and replacing the adsorption filter screen of the present invention;

[0026] Fig.10 It is a schematic diagram of installation and replacement of the orifice plate of the present invention;

[0027] Fig.11 It is a working schematic diagram and flow chart of the present invention;

[0028] Fig.12 It is a schematic diagram and a flow chart of the cleaning of the present invention.

[0029] In the attached figure: steam inlet 1; machine body 2; pressure difference transmitter 3; cleaning water inlet 4; outlet chamber 5; annular pipe 6; wastewater inlet 7; inspection hole 8; sewage outlet 9; spiral groove or spiral blade 10; drainage pipe 11; expansion chamber 12; funnel-shaped baffle 13; rotating acceleration tube 14; atomizing nozzle 15; orifice plate 16; mixing chamber 17; adsorption filter 18; steam outlet 19; nozzle hole 20. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] The following is a further detailed description of the implementation of the present invention in conjunction with the accompanying drawings:

[0032] See Figure 1 , Figure 2 , comprising a body 2, a steam inlet 1 and a steam outlet 19 at both ends of the body 2, and a wastewater inlet 7 at the side end, characterized in that: the body 2 is provided with an expansion chamber 12 connected to the steam inlet 1, an outlet chamber 5 connected to the steam outlet 19, and a mixing chamber 17 between the expansion chamber 12 and the outlet chamber 5, the expansion chamber 12 and the mixing chamber 17 are connected through a rotating acceleration tube 14, an adsorption filter 18 for adsorbing salt and intercepting impurities is provided between the mixing chamber 17 and the outlet chamber 5, the wastewater inlet 7 is connected to the rotating acceleration tube 14 through an annular pipe 6; steam enters from the steam inlet 1, enters the rotating acceleration tube 14 after passing through the expansion chamber 12, the steam is accelerated by the rotating acceleration tube 14 to generate a vortex, and is fully contacted and gasified with the waste gas entering from the annular pipe 6 at the rear section of the rotating acceleration tube 14, the gasified boiler wastewater and steam form mixed steam in the mixing chamber 17, the salt in the mixed steam is adsorbed and intercepted by the adsorption filter 18, and the filtered steam is discharged from the steam outlet 19 through the outlet chamber 5.

[0033] The steam is accelerated by the rotating accelerating tube to produce a swirl. The speed of the swirl is proportional to the flow rate of the steam. The faster the flow rate, the faster the rotation speed. The steam contacts the wastewater sprayed from the annular pipe at the rear section of the rotating accelerating tube and vaporizes (flash evaporation). Since the steam medium passing through is in a rotating circulation state, the contact area between the steam medium and the wastewater is increased, which is beneficial to improve the uniformity between the steam and the wastewater.

[0034] Since the inorganic salts contained in the wastewater will not evaporate with the water, these salts form crystals on the adsorption filter when passing through the adsorption filter and are adsorbed on the adsorption filter. At the same time, the impurities in the wastewater are directly intercepted by the adsorption filter, and the steam can pass through the adsorption filter smoothly, so that the mixed steam is desalted and purified. The quality of the purified mixed steam can reach the quality of the original steam.

[0035] Taking advantage of the high temperature and high pressure characteristics of boiler wastewater, the saturated steam of the boiler is used to flash and mix the wastewater, making it gasified instantly. The salt and impurities that cannot be evaporated in the wastewater are then removed through adsorption and filtration by the adsorption filter, so that the purified steam can continue to be supplied to equipment such as turbines or other users, so as to achieve the purpose of energy saving and zero emissions.

[0036] See Figure 3 The funnel-shaped baffle 13 and the adsorption filter 18 divide the interior of the device into three areas, namely, the expansion chamber 12, the mixing chamber 17 and the outlet chamber 5. The adsorption filter 18 is a replaceable component, generally divided into several pieces, so as to facilitate the insertion or removal from the inspection port, and is fixed to the inner wall of the body 2 with bolts. The funnel-shaped baffle 13 is used to reduce the impact of the medium and reduce the flow resistance of the medium, so as to reduce the impact of the steam entering the port on the subsequent equipment, and at the same time guide the steam into the rotating acceleration tube 14.

[0037] See Figure 4 The rotating accelerating tube 14 is composed of a section of pipe with spiral blades or spiral grooves and a section of smooth pipe, which mainly shrinks the flow cross section of the medium. Under the condition of constant flow rate, the steam flow rate after entering the rotating accelerating tube is accelerated, and because the spiral blades or spiral grooves are arranged inside the tube wall, the medium passing through the tube rotates and enters the smooth tube at the rear section. Under the condition of high speed and rotation, the fluid in the smooth tube fully contacts the wastewater sprayed from the atomizing nozzles arranged in a circle around the smooth tube, so that the wastewater is instantly evaporated into steam and merged into the mixing chamber. The smooth tube can reduce the rotation resistance.

[0038] See Figure 5 The rear end of the rotating acceleration tube 14 is a smooth inner wall, and a number of nozzle holes 20 are arranged around the smooth inner wall. The annular pipe 6 and the rotating acceleration tube 14 are connected through the atomizing nozzle 15 installed on the nozzle hole 20. The annular pipe 6 is an outer ring around the rear end of the rotating acceleration tube 14, and there is a large gap between the annular pipe 6 and the rotating acceleration tube 14. The top of the annular pipe 6 is connected to the wastewater inlet 7. High-salt wastewater enters the annular pipe 6 through the wastewater inlet 7, and then sprays the atomized wastewater into the smooth part of the rear end of the rotating acceleration tube 14 through the atomizing nozzle 15, and mixes with the high-temperature steam. The atomized wastewater increases the contact area between the steam medium and the wastewater, which is more conducive to improving the uniformity between the steam and the wastewater, so that the wastewater is instantly gasified. Figure 6, showing the connection relationship between the rotating acceleration pipe 14, the atomizing nozzle 15, and the annular pipe 6.

[0039] See Figure 7 The orifice plate 16 is placed at the outlet of the rotating accelerating tube 14 to mitigate the impact of the mixed medium sprayed from the rotating accelerating tube 14 on the adsorption filter 18 behind it. At the same time, in order to facilitate maintenance and replacement, the orifice plate 16 can generally be divided into several pieces and fixed to the inner wall of the body 2 with bolts.

[0040] See Figure 8 The adsorption filter 18 is a nano-scale metal filter used to adsorb and filter inorganic salts in the mixed medium. It needs to be replaced after adsorbing too much inorganic salts, so it is a consumable part. In order to facilitate maintenance and replacement from the manhole 8, it is generally divided into several pieces and fixed to the inner wall of the body 2 with bolts.

[0041] There is an inspection hole 8 on the top (or side) of the body 2, which is convenient for maintenance personnel to enter and exit the equipment for maintenance work, and is also convenient for replacing the internal adsorption filter 18 and orifice plate 16; there are also three cleaning water inlets 4 on the top of the body 2, which are used to inject water and clean different internal areas (expansion chamber 12, mixing chamber 17, outlet chamber 5).

[0042] The bottom of the machine body 2 is provided with a sewage outlet 9 relative to each area (expansion chamber 12, mixing chamber 17, outlet chamber 5), and the sewage outlet 9 is connected to a drainage pipe 11 for discharging cleaning water and impurities.

[0043] A pressure differential indicator 3 is provided in the expansion chamber 12 and the outlet chamber 5 inside the machine body 2. The pressure differential indicator 3 can be a pressure transmitter or an electric contact pressure gauge or other device for measuring the internal pressure of the machine body. By detecting the pressure difference between the steam inlet 1 and the steam outlet 19, the degree of blockage of the adsorption filter 18 is determined, and it is determined whether it needs to be cleaned.

[0044] See Fig. 9 As shown, it shows the installation or replacement of the adsorption filter 18 through the manhole 8;

[0045] See Fig.10 As shown, it shows the installation or replacement of the orifice plate 16 through the manhole 8;

[0046] See Fig.11As shown, the working process of the present invention is that steam enters from the steam inlet, enters the rotating acceleration tube after passing through the expansion chamber, the steam is accelerated by the rotating acceleration tube to generate a vortex, and is fully contacted and gasified with the exhaust gas entering from the annular pipe at the rear section of the rotating acceleration tube, the gasified boiler waste water and steam form mixed steam in the mixing chamber, the salt in the mixed steam is adsorbed and retained by the adsorption filter, the filtered steam is discharged from the steam outlet through the outlet chamber, and the purified steam can continue to be supplied to equipment such as steam turbines or other users for use, so as to achieve the purpose of energy saving and zero emission.

[0047] See Fig.12 As shown, when the adsorption filter is blocked, cleaning water is injected from the cleaning water inlet 4 to fill and soak the entire internal area of ​​the body 2 (expansion chamber 12, mixing chamber 17, outlet chamber 5), and the water is discharged from the drain outlet 9 after cleaning is completed.

[0048] The rated pressure of steam produced by general industrial boilers is 1.0~3.8MPa (180-247℃) or higher, while the pressure of steam required by most heat users is roughly 0.5-3.5MPa (152-243℃), so there is a pressure difference and temperature difference. Therefore, in order to meet the needs of heat users, most companies are equipped with "double reduction" (temperature and pressure reduction device) between steam extraction from boilers or steam turbines and steam output. Desalted water needs to be added when "double reduction" is used. When wastewater and steam are mixed, the temperature or pressure of the original steam decreases. It is adjusted by "double reduction" to reduce temperature and pressure. If there is less or no reduction, the temperature or pressure of the output steam remains unchanged through this device, and a large amount of desalted water is saved at the same time (the amount saved is approximately equal to the amount of wastewater recovered).

[0049] This not only recycles and treats boiler wastewater, avoiding direct discharge, but also recycles almost 99% of the medium heat of high-temperature wastewater (except for pipeline losses, etc.), and also saves desalted water, achieving the goals of energy saving and zero emissions.

[0050] According to GB / T1576-2018, Tables 1 to 4 give the requirements for boiler water quality under different steam pressures. From the conductivity index, the value of boiler feed water conductivity (25°C) when the steam pressure (MPa) is 2.5<p<3.8 is: conductivity ≤80.0μS / cm. This value is the highest requirement for water quality of industrial boilers under various pressures. We use this conductivity as the target of wastewater treatment. At the same time, the minimum requirement for boiler water quality under this standard is 6.4×10 3 μS / cm, and this conductivity is used as the influent quality for wastewater treatment.

[0051] The following test data are respectively the test data of steam before entering the device (Table 1) and the test data of steam after mixing with wastewater at the outlet of the device:

[0052] Table 1

[0053]

[0054] Table 2

[0055]

[0056] It can be seen from the test data that the pH value of the input steam is 8.76, the conductivity is 5.54μs / cm, and the hardness (CaCO2) is 1.14mg / L. The pH value of the outlet steam after the steam and wastewater are mixed and treated in the device of the present invention is 7.97, the conductivity is 5.02μs / cm, and the hardness (CaCO2) is 0.442mg / L. From the parameter of conductivity, the difference in the input and output steam quality (water quality) is very small, and its absolute value is much smaller than the requirements for feed water and boiler water in GB / T1576-2018. The steam after the steam and wastewater are mixed and treated in the device of the present invention can continue to be supplied to heat users.

Claims

1. A boiler wastewater desalination and mixing device, comprising a body, a steam inlet and an outlet at both ends of the body, and a wastewater inlet at the side end, characterized in that: The body is provided with an expansion chamber connected to the steam inlet, an outlet chamber connected to the steam outlet, and a mixing chamber between the expansion chamber and the outlet chamber, the expansion chamber and the mixing chamber are connected through a rotating acceleration tube, an adsorption filter is provided between the mixing chamber and the outlet chamber, and the wastewater inlet is connected to the rotating acceleration tube through an annular pipeline; steam enters from the steam inlet, enters the rotating acceleration tube after passing through the expansion chamber, and is accelerated by the rotating acceleration tube to generate a vortex, and is fully contacted with the wastewater entering from the annular pipeline at the rear section of the rotating acceleration tube to gasify the wastewater, the gasified boiler wastewater and steam form mixed steam in the mixing chamber, the salt in the mixed steam is adsorbed and intercepted by the adsorption filter, and the filtered steam is discharged from the steam outlet through the outlet chamber; the rotating acceleration tube is provided with a spiral groove or a spiral blade on the inner wall of the front section connected to the expansion chamber; the rear end of the rotating acceleration tube is a smooth inner wall, and a plurality of nozzle holes are provided circumferentially on the smooth inner wall, and the annular pipeline and the rotating acceleration tube are connected by an atomizing nozzle installed on the nozzle hole.

2. A boiler wastewater desalination and mixing device as claimed in claim 1, characterized in that: The flow cross section of the expansion chamber is larger than the flow cross section of the pipeline at the steam inlet, and a funnel-shaped baffle is provided at the connection between the expansion chamber and the rotating acceleration tube.

3. A boiler wastewater desalination and mixing device as claimed in claim 1 or 2, characterized in that: An orifice plate is provided at the outlet side of the rotating accelerating tube, and the orifice plate is composed of a plurality of orifice plates provided with flow holes.

4. A boiler wastewater desalination and mixing device as claimed in claim 3, characterized in that: The flow cross section of the mixing chamber is larger than the flow cross section of the rotating accelerating tube, and an inspection hole is arranged on the upper side or the side side of the mixing chamber.

5. A boiler wastewater desalination and mixing device as claimed in claim 3, characterized in that: The adsorption filter is made of nano-scale metal filter.

6. A boiler wastewater desalination and mixing device as claimed in claim 1, 2 or 5, characterized in that: The adsorption filter screen is composed of a plurality of filter screens.

7. A boiler wastewater desalination and mixing device as claimed in claim 6, characterized in that: A pressure difference transmitter is respectively arranged on the upper side of the expansion chamber and the outlet chamber.

8. A boiler wastewater desalination and mixing device as claimed in claim 6, characterized in that: The expansion chamber, the mixing chamber and the outlet chamber are each provided with a sewage outlet at the lower side and a cleaning water inlet at the upper side.

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