Method for purifying asphalt flue gas

Abstract

The invention provides an asphalt flue gas purification method, the method is based on an asphalt flue gas purification system, and the asphalt flue gas purification system comprises a lithium bromide water chilling unit, a condensed water pump and an asphalt flue gas purification unit; the asphalt flue gas purification unit comprises a refrigeration water circulator, a 1 # condenser, a 2 # condenser, a 1 # condenser asphalt storage tank and a 2 # condenser asphalt storage tank; the lithium bromide water chilling unit is respectively connected with the 1 # condenser and the 2 # condenser through a refrigeration water circulator; the first condenser and the second condenser are each internally provided with a vertical S-shaped pipe bundle. The 1 # condenser and the 2 # condenser are connected with an asphalt flue gas pipeline through a flue gas inlet and a flue gas outlet; the vertical S-shaped pipe bundles are connected with a steam pipeline and a refrigeration water pipeline through steam / refrigeration water inlets and connected with a condenser outlet dead steam pipeline and a condenser outlet refrigeration water pipeline through dead steam / refrigeration water outlets. A 1 # condenser asphalt storage tank is connected below the 1 # condenser; a 2 # condenser asphalt storage tank is connected below the 2 # condenser; the device effectively collects asphalt in the asphalt flue gas and purifies the asphalt flue gas at the same time, and energy conservation and environmental protection are achieved.

Description

Technical Field

[0001] The present invention relates to a flue gas purification technology in the field of environmental protection, and more specifically, to a method for purifying asphalt flue gas. Background Art

[0002] In industrial fields such as coking and coal chemical industry, petroleum refining, and pre-baked anodes for aluminum carbon, asphalt-containing flue gas will be generated. At present, the main methods for treating or purifying asphalt-containing flue gas include activated carbon or molecular sieve adsorption method, electrostatic precipitator method, spray tower or Venturi scrubber method, combustion method, etc., as well as multi-stage purification methods that are combinations of the above various methods.

[0003] The solidification temperature of asphalt is usually between 50 and 70 °C, and the lower the temperature, the faster the solidification rate. The softening point is generally between 40 and 60 °C, and the higher the temperature, the better the fluidity of asphalt. According to the temperature characteristics of asphalt, the present invention proposes a method combining condensation and heating to achieve the purpose of purifying asphalt flue gas and effectively collecting asphalt. Summary of the Invention

[0004] The present invention provides a method for purifying asphalt flue gas. The method for purifying asphalt flue gas mainly consists of a condenser, a lithium bromide water chiller, an asphalt storage tank, as well as a flue gas pipeline, a steam pipeline, and necessary pipeline valves, etc. By using steam, the lithium bromide water chiller is used to produce low-temperature chilled water. The low-temperature chilled water flows through the condenser to cool the temperature of the flue gas, so that the asphalt in the flue gas condenses on the outer wall of the pipeline. When the condensation effect deteriorates, low-pressure steam is introduced into the condenser pipeline to heat the asphalt condensed on the outer wall of the pipeline, and the softened asphalt flows into the asphalt storage tank by gravity.

[0005] Specifically, the present invention is realized through the following technical solutions:

[0006] A method for purifying asphalt flue gas, the method is based on an asphalt flue gas purification system, and the asphalt flue gas purification system includes a lithium bromide water chiller, a condensate water pump, and an asphalt flue gas purification unit; the asphalt flue gas purification unit includes a refrigeration water circulator, a 1# condenser, a 2# condenser, a 1# condenser asphalt storage tank, and a 2# condenser asphalt storage tank; the lithium bromide water chiller is respectively connected to the 1# condenser and the 2# condenser through the refrigeration water circulator; vertical serpentine tube bundles are provided inside both the 1# condenser and the 2# condenser; both the 1# condenser and the 2# condenser are connected to the asphalt flue gas pipeline through a flue gas inlet and a flue gas outlet; the vertical serpentine tube bundles are respectively connected to the steam pipeline and the chilled water inlet pipeline through a steam / chilled water inlet, and the vertical serpentine tube bundles are respectively connected to the condenser outlet exhaust steam pipeline and the condenser outlet chilled water pipeline through an exhaust steam / chilled water outlet; a 1# condenser asphalt storage tank is connected below the 1# condenser; a 2# condenser asphalt storage tank is connected below the 2# condenser: wherein:

[0007] One path of the lithium bromide water chiller condenses the input steam at 0.4 - 1.0 MPa through lithium bromide solution, and the condensed water is discharged through the condensate pipeline and the condensate water pump.

[0008] Another path of the lithium bromide water chiller supplies the 1# condenser and the 2# condenser respectively through the chilled water supply pipeline and the chilled water circulator. The 7°C chilled water exchanges heat with the input asphalt flue gas in the 1# condenser and the 2# condenser respectively, causing the asphalt to condense on the outer wall of the vertical serpentine tube bundle inside the 1# condenser and the 2# condenser. After absorbing the heat of the asphalt flue gas, the temperature of the chilled water rises to 10°C - 14°C and returns to the lithium bromide water chiller, and the chilled water at 5°C - 9°C is generated after heat exchange; then it is supplied to the 1# condenser and the 2# condenser respectively through the chilled water supply pipeline and the chilled water circulator again, and this cycle repeats. Among them:

[0009] The asphalt flue gas purification unit alternately purifies the input asphalt flue gas through the 1# condenser and the 2# condenser respectively, including:

[0010] When the 1# condenser conducts the heating operation to soften and collect the asphalt, the 2# condenser inputs chilled water, and the asphalt in the flue gas condenses on the outer wall of the vertical serpentine tube bundle of the 2# condenser; when the 2# condenser conducts the heating operation to soften and collect the asphalt, the 1# condenser inputs chilled water, and the asphalt in the condensed flue gas condenses on the outer wall of the vertical serpentine tube bundle of the 1# condenser. The two condensers operate alternately, and the operations of the flue gas, steam, and chilled water are all realized through valves.

[0011] Furthermore, the processes of collecting asphalt by the 1# condenser and the 2# condenser respectively include:

[0012] When the asphalt on the vertical serpentine tube bundle of the 1# condenser agglomerates too thickly, the inlet and outlet flue gas valves of the 1# condenser are closed, the inlet and outlet chilled water valves are closed, and the steam inlet valve and the condenser exhaust steam outlet valve of the 1# condenser are opened. At this time, the function of the 1# condenser is transformed into a heater, and the steam flows through the vertical serpentine tube bundle to heat the asphalt condensed on the outer wall of the vertical serpentine tube bundle. After the asphalt is softened, it flows into the asphalt storage tank; while the 1# condenser is heating and collecting asphalt, the 2# condenser inputs chilled water to cool and purify the flue gas.

[0013] When the asphalt condenses too thickly on the vertical serpentine tube bundle of the 2# condenser, close the flue gas valves at the inlet and outlet of the 2# condenser, close the refrigerated water inlet and outlet valves, and open the steam inlet valve and the exhausted steam outlet valve of the 2# condenser. At this time, the function of the 2# condenser is transformed into a heater. The steam flows through the vertical serpentine tube bundle to heat the asphalt condensed on the outer wall of the vertical serpentine tube bundle. After the asphalt softens, it flows into the asphalt storage tank; while the 2# condenser is heating the asphalt and collecting the asphalt, the 1# condenser inputs refrigerated water to cool and purify the flue gas.

[0014] Beneficial effects

[0015] 1. In industrial fields such as coking and coal chemical industry, petroleum refining, and pre-baked anodes for aluminum carbon, low-pressure steam is easily obtained in factories. Compared with the combustion method, the present invention can greatly reduce the operating cost of asphalt flue gas treatment.

[0016] 2. By setting up a lithium bromide water chiller, the present invention can easily realize the preparation of refrigerated water, and the temperature of the refrigerated water can reach 7°C, which provides good conditions for cooling asphalt flue gas and condensing asphalt.

[0017] 3. The present invention uses low-pressure steam to heat the asphalt, which belongs to a physical reaction, making it soften and flow into the asphalt storage tank. This method for recovering asphalt is simple and feasible, and can turn waste into treasure.

[0018] 4. The present invention sets two condensers, and the two condensers alternately operate the heating and refrigeration functions, enabling the system to operate continuously and continuously purify the asphalt flue gas.

[0019] 5. The vertical serpentine tube bundle is arranged in the condenser of the present invention, which is beneficial for the softened asphalt to fall into the asphalt storage tank by gravity. Description of the drawings

[0020] Figure 1 It is a schematic structural diagram of a system based on a method for purifying asphalt flue gas of the present invention.

[0021] Reference numerals:

[0022] 101, lithium bromide water chiller; 102, condensate water pump; 103, refrigerated water circulator;

[0023] 201, 1# condenser; 202, 2# condenser; 203, 1# condenser asphalt storage tank; 204, 2# condenser asphalt storage tank.

[0024] The main valve markings are as follows:

[0025] ①, 1# condenser steam inlet valve; ②, 2# condenser steam inlet valve;

[0026] ③, 1# Condenser Refrigerated Water Inlet Valve; ④, 2# Condenser Refrigerated Water Inlet Valve;

[0027] ⑤, 1# Condenser Exhaust Steam Outlet Valve; ⑥, 2# Condenser Exhaust Steam Outlet Valve;

[0028] ⑦, 1# Condenser Refrigerated Water Outlet Valve; ⑧, 2# Condenser Refrigerated Water Outlet Valve;

[0029] ⑨, Steam Inlet Valve of Lithium Bromide Chiller; ⑩, Condensate Outlet Valve of Lithium Bromide Chiller;

[0030] 1# Condenser Flue Gas Inlet Valve; 2# Condenser Flue Gas Inlet Valve;

[0031] 1# Condenser Flue Gas Outlet Valve; 2# Condenser Flue Gas Outlet Valve;

[0032] 1# Cooler Asphalt Storage Tank Plug Valve; 2# Cooler Asphalt Storage Tank Plug Valve. Detailed Implementation Manner

[0033] The following combines with the attached Figure 1 to further elaborate on the present invention.

[0034] A method for purifying asphalt fumes, the main purposes are: one is to cool the asphalt-containing fumes so that the fume temperature is lower than the asphalt solidification point, and the asphalt condenses and adheres to the outer wall of the pipeline, achieving the purpose of removing asphalt from the asphalt fumes and purifying the fumes; the other is to heat the pipeline so that the asphalt adhered to the outer wall of the pipeline softens and flows, and finally falls into the asphalt storage tank, achieving the purpose of asphalt recovery.

[0035] An asphalt purification system for asphalt fumes consists of a lithium bromide chiller 101, a condensate water pump 102, a refrigeration water circulator 103, a 1# condenser 201, a 2# condenser 202, a 1# condenser asphalt storage tank 203, a 2# condenser asphalt storage tank 204, as well as flue gas pipelines, steam-water pipelines, valves, etc. Additionally, it includes ①~ Main valve. Specifically, the asphalt fume purification system includes a lithium bromide chiller 101, a condensate pump 102, and an asphalt fume purification unit; the asphalt fume purification unit includes a refrigeration water circulator 103, a 1# condenser 201, a 2# condenser 202, a 1# condenser asphalt storage tank 203, and a 2# condenser asphalt storage tank 204; the lithium bromide chiller 101 is connected to the 1# condenser 201 and the 2# condenser 202 respectively through the refrigeration water circulator 103; vertical serpentine tube bundles are provided inside both the 1# condenser 201 and the 2# condenser 202; both the 1# condenser 201 and the 2# condenser 202 are connected to the asphalt fume pipeline through a flue gas inlet and a flue gas outlet; the vertical serpentine tube bundles are connected to the steam pipeline and the refrigeration water pipeline through a steam / refrigeration water inlet, and the vertical serpentine tube bundles are connected to the condenser outlet exhaust steam pipeline and the condenser outlet refrigeration water pipeline through an exhaust steam / refrigeration water outlet; a 1# condenser asphalt storage tank 203 is provided below the 1# condenser and is connected thereto; a 2# condenser asphalt storage tank 204 is provided below the 2# condenser 202 and is connected thereto; as Figure 1 shown, where:

[0036] One lithium bromide chiller 101 is provided, which can generally utilize steam at 0.4 - 1.0 MPa. The principle of the lithium bromide chiller 101 is to achieve the refrigeration purpose by using the absorption and release of the heat of water vapor by the lithium bromide solution at different temperatures. After the steam evaporates the lithium bromide solution in the lithium bromide unit, the steam condenses into condensate, and the condensate is discharged through the condensate pipeline and the condensate pump 102. The lithium bromide chiller 101 generates 7°C chilled water, which is supplied to the 1# condenser and the 2# condenser through the chilled water supply pipeline and the refrigeration water circulator 103. The 7°C chilled water exchanges heat with the asphalt fumes in the condenser, reducing the flue gas temperature and causing the asphalt to condense on the outer wall of the vertical serpentine pipes in the condenser. After absorbing the heat of the asphalt fumes, the chilled water temperature rises to 12°C and returns to the lithium bromide chiller 101.

[0037] Two condensers are provided: Condenser No. 1 (201) and Condenser No. 2 (202). The condenser is a horizontal heat exchanger with vertical serpentine tube bundles inside. Refrigerated water and steam are alternately introduced into the vertical serpentine tube bundles. The steam / refrigerated water inlets of the vertical serpentine tube bundles of the condenser are connected to the steam pipeline and the refrigerated water pipeline. The exhaust steam outlet of the vertical serpentine tube bundles of the condenser is connected to the exhaust steam pipeline at the condenser outlet. The exhaust steam outlet, the refrigerated water outlet of the vertical serpentine tube bundles of the condenser and the refrigerated water drainage pipeline are connected. Each condenser is provided with a flue gas inlet and a flue gas outlet. The asphalt-containing flue gas enters the condenser from the flue gas inlet. After the asphalt flue gas flows through the vertical serpentine tubes of the condenser, the temperature decreases, and the asphalt condenses on the outer wall of the vertical serpentine tubes, achieving the purpose of removing asphalt from the asphalt flue gas. The clean flue gas is discharged from the flue gas outlet of the condenser. Each condenser is provided with an asphalt discharge outlet, and the asphalt discharge outlet is connected to the asphalt storage tank of the condenser.

[0038] For the vertical serpentine tubes provided inside the condenser, when the thickness of the condensed asphalt becomes larger and the heat transfer effect decreases, the flue gas inlet and outlet valves of this condenser are closed, the refrigerated water inlet and outlet valves are closed, and the steam inlet valve and the exhaust steam outlet valve of this condenser are opened. At this time, the function of the condenser is transformed into a heater. The steam flows through the vertical serpentine tube bundles to heat the asphalt condensed on the outer wall of the pipeline. After the asphalt softens, it flows to the asphalt storage tank by gravity. While the asphalt is being heated and collected in this condenser, the other condenser is introduced with refrigerated water to cool and purify the flue gas. That is, when Condenser No. 1 (201) is performing the heating operation to collect asphalt, Condenser No. 2 (202) is introduced with refrigerated water to condense the asphalt in the flue gas. When Condenser No. 2 (202) is performing the heating operation to collect asphalt, Condenser No. 1 (201) is introduced with refrigerated water to condense the asphalt in the flue gas. The two condensers operate alternately, and the operations of their flue gas, steam, and refrigerated water are all realized through valves. In order to reduce the manual operation amount, electric valves are set for all the valves.

[0039] For the asphalt storage tank of the condenser, an asphalt storage tank is provided below each condenser. According to the specific design of the condenser, one to multiple asphalt storage tanks can be set. The asphalt storage tank is used to receive and store asphalt. After the asphalt storage tank is full, it is transported away, and an empty storage tank is placed again below the asphalt discharge outlet. A flap valve is set at the inlet of the asphalt storage tank.

[0040] The present invention also provides a method for purifying asphalt fume. The method mainly includes a lithium bromide water chiller 101, which is provided with a steam inlet, a condensate outlet, a chilled water outlet, and a chilled water return inlet, and is respectively connected to a steam pipeline, a condensate pipeline, a chilled water supply pipeline, and a chilled water return pipeline. Before the steam pipeline enters the lithium bromide water chiller 101, two other steam pipelines are connected from the pipeline, which are respectively used to supply steam to the 1# condenser 201 and the 2# condenser 202. The condensate pipeline is connected to a condensate water pump 102 to drain the condensate. The chilled water supply pipeline is connected to two chilled water circulators 103, and the two water pumps are connected in parallel and are used as spares for each other during actual operation. Two chilled water supply pipelines are provided at the outlet of the chilled water circulator 103, which are respectively connected to the steam pipelines at the inlets of the 1# condenser 201 and the 2# condenser 202, and finally the steam / chilled water inlets of the 1# condenser 201 and the 2# condenser 202 are formed. The chilled water outlets of the 1# condenser 201 and the 2# condenser 202 are connected to the chilled water return pipeline, and the chilled water return pipeline is finally connected to the chilled water return inlet of the lithium bromide water chiller 101. Through the above steps, by setting the lithium bromide water chiller, the present invention can relatively easily realize the preparation of chilled water, and the temperature of the chilled water can reach 7°C, which provides good conditions for cooling asphalt fume and condensing asphalt. At the same time, the present invention heats the asphalt by using low-pressure steam by converting the condenser into a heater, so that it softens and flows into the asphalt storage tank. This method recovers the asphalt, the system is simple, the investment is reduced, and the waste asphalt can be collected and turned waste into treasure.

[0041] The asphalt fume purification unit includes a 1# condenser 201 and a 2# condenser 202. The flue gas inlets of the two condensers are respectively connected to a flue gas inlet pipeline, and the flue gas outlets of the two condensers are respectively connected to a flue gas outlet pipeline. The two condensers are also respectively provided with a steam / chilled water inlet, an exhaust steam outlet, and a chilled water outlet. The steam / chilled water inlet is connected to a steam pipeline and a chilled water supply pipeline, the exhaust steam outlet is connected to an exhaust steam pipeline, and the chilled water outlet is connected to a chilled water return pipeline, and finally returns to the chilled water return inlet of the lithium bromide water chiller 101. Asphalt discharge outlets are arranged at the lower parts of the 1# condenser 201 and the 2# condenser 202. According to the design, one or more asphalt discharge outlets are arranged for each condenser.

[0042] As described above, the present invention can achieve two purposes of heating and cooling, and for the two functions of heating and cooling, the 1# condenser 201 and the 2# condenser 202 interactively realize the heating and cooling functions during actual operation. The specific implementation method is as follows:

[0043] When the 1# condenser 201 is cooling and the 2# condenser 202 is heating, the asphalt fume enters the 1# condenser 201. At this time, the steam does not enter the 1# condenser 201, and the exhaust steam outlet of the 1# condenser 201 is also in a closed state; the cooling water inlet and the cooling water outlet of the 1# condenser 201 are in an open state. At this time, for the 1# condenser, the cooling water cools the asphalt fume, and the asphalt condenses on the outer wall of the vertical serpentine tube bundle of the 1# condenser. At the same time, for the 2# condenser, the asphalt fume does not enter the 2# condenser, the steam enters the 2# condenser, the exhaust steam pipeline of the 2# condenser is in an open state, and the cooling water inlet and the cooling water outlet of the 2# condenser are in a closed state.

[0044] When the 1# condenser 201 is heating and the 2# condenser 202 is cooling, the operation method is the reverse of the above description.

[0045] Through the alternate operation of the heating and cooling functions by two condensers in the present invention, the system can operate continuously and can continuously purify the asphalt fume.

[0046] In the two operating states, the opening / closing states of each valve are as follows:

[0047]

[0048] The above are only the preferred embodiments of the present invention, but the present invention is not limited to the above specific embodiments. For those of ordinary skill in the art, without departing from the creative concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. A method for purifying asphalt fume, characterized in that: The method is based on an asphalt flue gas purification system, which includes a lithium bromide chiller, a condensate pump and an asphalt flue gas purification unit; the asphalt flue gas purification unit includes a refrigeration water circulator, a No. 1 condenser, a No. 2 condenser, a No. 1 condenser asphalt storage tank, and a No. 2 condenser asphalt storage tank; the lithium bromide chiller is connected to the No. 1 condenser and the No. 2 condenser respectively through a refrigeration water circulator; the No. 1 condenser and the No. 2 condenser are both provided with vertical serpentine tube bundles; the No. 1 condenser and the No. 2 condenser are both connected to an asphalt flue gas pipeline through a flue gas inlet and a flue gas outlet; the vertical serpentine tube bundles are connected to a steam pipeline and a refrigeration water pipeline through a steam / refrigeration water inlet, and the vertical serpentine tube bundles are connected to a condenser outlet exhaust steam pipeline and a condenser outlet refrigeration water pipeline through an exhaust steam / refrigeration water outlet; the No. 1 condenser is connected to a No. 1 condenser asphalt storage tank below; the No. 2 condenser is connected to a No. 2 condenser asphalt storage tank below: wherein: The lithium bromide chiller condenses the input 0.4-1.0 MPa steam through lithium bromide solution to generate condensed water, which is discharged through the condensed water pipeline and condensed water pump; The other route of the lithium bromide chiller is supplied to the 1# condenser and the 2# condenser through the cooling water supply pipeline and the cooling water circulating water device. The cooling water exchanges heat with the input asphalt flue gas in the 1# condenser and the 2# condenser, so that the asphalt condenses on the outer wall of the vertical serpentine tube bundle inside the 1# condenser and the 2# condenser. After absorbing the heat of the asphalt flue gas, the cooling water rises to 10°C to 14°C and returns to the lithium bromide chiller. After heat exchange, 5°C to 9°C cooling water is generated; it is supplied to the 1# condenser and the 2# condenser through the cooling water supply pipeline and the cooling water circulating water device again, and the cycle is repeated, wherein: The asphalt fume purification unit performs purification treatment on the input asphalt fume alternately through the 1# condenser 201 and the 2# condenser 202, including: When the 1# condenser is heating, softening and collecting asphalt, cooling water is input to the 2# condenser, and the asphalt in the flue gas condenses on the outer wall of the vertical serpentine tube bundle of the 2# condenser; when the 2# condenser is heating, softening and collecting asphalt, cooling water is input to the 1# condenser, and the asphalt in the flue gas condenses on the outer wall of the vertical serpentine tube bundle of the 1# condenser. The two condensers are operated alternately, and the operation of the flue gas, steam and cooling water is achieved through valves.

2. The asphalt fume purification method according to claim 1, characterized in that: in: The 1# condenser and the 2# condenser collect asphalt respectively, including: When the asphalt on the vertical serpentine tube bundle of the 1# condenser is too thick, the inlet and outlet flue gas valves of the 1# condenser are closed, the inlet and outlet valves of the refrigerating water are closed, and the steam inlet valve of the 1# condenser and the exhaust steam outlet valve of the condenser are opened. At this time, the function of the 1# condenser is transformed into a heater, and the steam flows through the vertical serpentine tube bundle to heat the asphalt condensed on the outer wall of the vertical serpentine tube bundle, and the asphalt flows into the asphalt storage tank after softening; while the 1# condenser is heating and collecting asphalt, the 2# condenser inputs refrigerating water to cool and purify the flue gas; When the asphalt on the vertical serpentine tube bundle of the 2# condenser is too thick, the inlet and outlet flue gas valves of the 2# condenser are closed, the inlet and outlet valves of the cooling water are closed, and the steam inlet valve of the 2# condenser and the exhaust steam outlet valve of the condenser are opened. At this time, the role of the 2# condenser is transformed into a heater, and the steam flows through the vertical serpentine tube bundle to heat the asphalt condensed on the outer wall of the vertical serpentine tube bundle. After the asphalt is softened, it flows into the asphalt storage tank; while the 2# condenser is heating and collecting asphalt, the 1# condenser inputs cooling water to cool and purify the flue gas.

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