Membrane method processing system and process for high-concentration salt-containing organic waste liquid incineration exhaust gas

Abstract

A membrane method processing system and process for a high-concentration salt-containing organic waste liquid incineration exhaust gas is described. The system consists essentially of a waste liquid incinerator (I), a gas-solid separator (II), a heat exchanger (III), an air blower (IV), an anti-caking agent storage tank (V), a membrane method dust cleaner (VI), an induced draft fan (VII), a check valve (VIII), and a desulfurization tower (IX). The present invention introduces the dust collecting membrane into the tail gas treatment system and utilizes the small pore size and high porosity of the dust collecting membrane to prevent inorganic salt particles from entering the internal of the filter material and agglomerating there. When the humidity of the gas entering the dust collector increases during the dust removing process, the anti-caking agent is also introduced into the tail gas treatment system to change the surface structure of the inorganic salt crystal to prevent the crystal from agglomeration.

Claims

1. A membrane system for treating incineration tail gas of a high-concentration salt-containing organic waste liquid is consisting essentially of a waste liquid incinerator (I), a gas-solid separator (II), a heat exchanger (III), an air blower (IV), an anti-caking agent storage tank (V), a membrane dust collector (VI), an induced draft fan (VII), a one-way valve (VIII) and a desulfurization tower (IX); wherein the membrane dust collector (VI) in a cylindrical shape and includes the following components: temperature and humidity sensors (1), anti-caking agent nozzle(s) (2), a membrane dust collector inlet (3), the dust collecting membrane (4), a pore board (5), an ash bucket (6), a middle box (7), an upper box (8), an insulating and heating device (9) and a backflush device (10); wherein the temperature and humidity sensors (1) and the anti-caking agent nozzle (2) are placed in the membrane dust collector inlet (3), the temperature and humidity sensors (1) are placed in front of the anti-caking agent nozzle (2), the anti-caking agent storage tank (V) is connected to the anti-caking agent nozzle (2) through the conveying pipe, the membrane dust collector inlet (3) is placed in the tangential direction of the middle box (7), the pore board (5) is placed between the middle box (7) and the upper box (8), and the dust collecting membrane (4) is arranged in a concentric circle on the pore board (5); the backflush device (10) is located at the upper part of the pore board (5) and is composed of multiple semicircular annular blowpipes (11), and the semicircular annular blowpipes (11) are connected to the air supply conduit (12), the insulating and heating device (9) is located in the middle box (7), and the ash bucket (6) is located in the lower part of the middle box (7) and is conical.

2. The membrane system for treating incineration tail gas of high-concentration salt-containing organic waste liquid described in claim 1, wherein the anti-caking agent nozzle (2) is one or more; if there are several anti-caking agent nozzles (2), they are evenly arranged annularly in the membrane dust collector inlet (3); and the anti-caking agent nozzle (2) is opened or closed manually or automatically.

3. The membrane system for treating incineration tail gas of high-concentration salt-containing organic waste liquid described in claim 1 wherein the pore board (5) has holes, the holes have a diameter of 10˜200 mm, a distance between centers of every two holes is 14˜400 mm, and the dust collecting membrane (4) is installed in the holes of the pore board.

4. The membrane system for treating incineration tail gas of high-concentration salt-containing organic waste liquid described in claim 1 wherein the dust collecting membrane (4) is an organic membrane or an inorganic membrane and has a two-layer structure, including a support layer and a membrane layer; the support layer has a pore size of 10˜200 μm, and the membrane layer has a pore size of 1˜10 μm; the membrane layer has a thickness of 10˜100 μm, and the organic membrane has a thickness of 0.4˜5 mm; the support layer material is glass fiber, polyester, polyphenylene sulfide, polyimide or polytetrafluoroethylene; the membrane material is polytetrafluoroethylene; the inorganic membrane is 3˜50 mm thick and its material is ceramic or metal; the ceramic material is alumina, zirconia or silicon carbide, and the metal material is stainless steel, nickel, iron chrome alloy or titanium.

5. The membrane system for treating incineration tail gas of high-concentration salt-containing organic waste liquid described in claim 1 wherein the semicircular annular blowpipe (11) is equipped with a blowing nozzle, and the center of the blowing nozzle is vertically aligned with the center of the pore board; and the dust collecting membrane (4) is reversely blown by the blowing nozzle when its filtration resistance is higher than the set value.

6. A process of treating incineration tail gas of high-concentration salt-containing organic waste liquid, comprising using the membrane system for the treatment of the incineration tail gas of high-concentration salt-containing organic waste liquid described in claim 1 to treat the incineration tail gas of high-concentration salt-containing organic waste liquid is comprised of following steps: (A) allowing high-temperature and high-concentration dust-containing gas (a) discharged from the waste liquid incinerator (I) to enter the gas-solid separator (II), and allowing the high-temperature dust-containing gas (b) after some dust is removed to enter the heat exchanger (III) to exchange heat; allowing the dust-containing gas after heat exchange (c) to enter the membrane dust collector (VI) for dust removal; (B) detecting the dust-containing gas entering the membrane dust collector inlet (3), by the temperature and humidity sensors (1); turning on the blower (IV) to deliver the anti-caking agent stored in the anti-caking agent tank (V) into the anti-caking agent nozzle (2) when the humidity is greater than a set value, and the anti-caking agent is uniformly ejected by the anti-caking agent nozzle (2); turning on the insulating and heating device (9) in the membrane dust collector (VI) automatically when the temperature is lower than the set value; (C) discharging the dust-free gas (d) purified by the membrane dust collector (VI) from the membrane dust collector by allowing the dust-free gas (d) flow into the desulfurization tower (IX) through the one-way valve and then allow it to be is after desulfurization.

7. The process for treating the incineration tail gas of high-concentration salt-containing organic waste liquid described in claim 6, wherein the dust-containing gas (c) in Step (A) has a temperature of 40˜800° C. when entering the membrane dust collector (VI); when the dust-containing gas (c) is filtered by the dust collecting membrane (4), the pressure difference across the membrane is 100˜3,000 Pa and the gas filtration rate is 5˜2.0 m/min.

8. The process for treating the incineration tail gas of high-concentration salt-containing organic waste liquid described in claim 6, wherein the anti-caking agent described in Step (B) is a powder solid and is composed of one or more selected from potassium ferrocyanide, sodium ferrocyanide, ammonium ferric citrate, tricalcium phosphate, ferrous tartrate and silica, talc, sodium dodecylbenzenesulfonate (SDBS), and the powder has a particle size of 10˜1,000 μm.

9. The process for treating the incineration tail gas of high-concentration salt-containing organic waste liquid described in claim 6, wherein the air blower (IV) described in Step (B) delivers the anti-caking agent to the anti-caking agent nozzle (2) automatically or manually.

10. The process for treating the incineration tail gas of high-concentration salt-containing organic waste liquid described in claim 6 the desulfurization tower (IX) described in Step (C) is a wet desulfurization tower, and the desulfurizer used therein is limestone-gypsum, ammonia, sodium carbonate, sodium bicarbonate, ammonium phosphate or magnesium oxide.

Description

DETAIL DESCRIPTION OF EMBODIMENTS

(1) The present invention will be described in detail below with reference to specific implementation cases. The following implementation cases are only used to illustrate the present invention, but are not intended to limit the implementation scope of the present invention.

(2) Implementation Case 1

(3) A membrane system for the treatment of the incineration tail gas of high-concentration salt-containing organic waste liquid is composed of a waste liquid incinerator (I), a gas-solid separator (II), a heat exchanger (III), an air blower (IV), an anti-caking agent storage tank (V), a membrane dust collector (VI), an induced draft fan (VII), a one-way valve (VIII) and a desulfurization tower (IX); the above-mentioned membrane dust collector (VI) has a cylindrical shape and includes the following components: temperature and humidity sensors (1), anti-caking agent nozzle(s) (2), a membrane dust collector inlet (3), the dust collecting membrane (4), a pore board (5), an ash bucket (6), a middle box (7), an upper box (8), an insulating and heating device (9) and a backflush device (10); the temperature and humidity sensors (1) and the anti-caking agent nozzle (2) are placed in the membrane dust collector inlet (3), the temperature and humidity sensors (1) are placed in front of the anti-caking agent nozzle (2), the anti-caking agent storage tank (V) is connected to the anti-caking agent nozzle (2) through the conveying pipe, the membrane dust collector inlet (3) is placed in the tangential direction of the middle box (7), the pore board (5) is placed between the middle box (7) and the upper box (8), and the dust collecting membrane (4) is arranged in a concentric circle on the pore board (5); the backflush device (10) is located at the upper part of the pore board (5) and is composed of multiple semicircular annular blowpipes (11), and the semicircular annular blowpipes (11) are connected to the air supply conduit (12), the insulating and heating device (9) is located in the middle box (7), and the ash bucket (6) is located in the lower part of the middle box (7) and is conical.

(4) The number of the anti-caking agent nozzle (2) is one, and the anti-caking agent nozzle (2) is opened or closed automatically. The pore board (5) has holes, the holes have a diameter of 10 mm, the distance between the centers of every two holes is 14 mm, and the dust collecting membrane (4) is installed in the holes of the pore board. The dust collecting membrane (4) is a two-layer organic membrane, including a support layer and a membrane layer; the support layer has a pore size of 10 μm, the membrane layer has a pore size of 1 μm, and the membrane layer has a thickness of 10 μm; the organic membrane has a thickness of 0.4 mm; the support layer material is polyester, and the membrane material is polytetrafluoroethylene. The membrane dust collector (VI) has a backflush system, which will reversely blow the dust collecting membrane (4) when the filtration resistance is above the set value.

(5) The specific operation process is as follows: (A) The high-temperature high-concentration dust-containing gas (a) discharged by the waste liquid incinerator (I) flows into the gas-solid separator (II). After part of the dust is separated, the high-temperature dust-containing gas (b) flows into the heat exchanger (III) for heat exchange. After heat exchange, the dust-containing gas (c) flows into the membrane dust collector (VI) for dust removal. When the dust-containing gas (c) enters the membrane dust collector (VI), its temperature is 40° C. When the dust-containing gas c is filtered by the dust collecting membrane (4), the pressure difference across the membrane is 100 Pa, and the gas filtration rate is 0.5 m/min. (B) The temperature and humidity sensors (1) detect the dust-containing gas entering the membrane dust collector inlet (3). When the humidity is greater than the set value, the air blower (IV) is automatically turned on to deliver anti-caking agent potassium ferrocyanide stored in the anti-caking agent storage tank (V) into the anti-caking agent nozzle (2). Potassium ferrocyanide has a particle size of 10 μm. The potassium ferrocyanide is evenly ejected by the anti-caking agent nozzle (2). When the temperature is lower than the set value, the insulating and heating device (9) in the membrane dust collector (VI) is automatically turned on. (C) The dust-free gas (d) purified by the membrane dust collector (VI) is discharged from the membrane dust collector. It flows into the desulfurization tower (IX) via a one-way valve and is then vented after desulfurization. The desulfurization tower (IX) is a wet desulfurization tower, and the desulfurizer used is limestone-gypsum.

(6) After the system has run stably for 8 months, it is found that the inorganic salt in the dust collector has no agglomeration, the surface of the dust collecting membrane has no inorganic salt aggregate, the running resistance is lower than 300 Pa, and the dust removal efficiency is higher than 99.9%.

(7) Implementation Case 2

(8) A membrane system for the treatment of the incineration tail gas of high-concentration salt-containing organic waste liquid has the same structure as implementation case 1. It has 5 anti-caking agent nozzles (2), which are arranged annularly in the membrane dust collector inlet (3). The pore board (5) has holes, the holes have a diameter of 200 mm, and the distance between the centers of every two holes is 400 mm. The dust collecting membrane (4) is a two-layer organic membrane, including a support layer and a membrane layer; the support layer has a pore size of 200 μm, the membrane layer has a pore size of 10 μm, and the membrane layer has a thickness of 100 μm; the organic membrane has a thickness of 5 mm; the support layer material is glass fiber, and the membrane layer material is polytetrafluoroethylene.

(9) The specific operation process is as follows: (A) The high-temperature high-concentration dust-containing gas (a) discharged by the waste liquid incinerator (I) flows into the gas-solid separator (II). After part of the dust is separated, the high-temperature dust-containing gas (b) flows into the heat exchanger (III) for heat exchange. After heat exchange, the dust-containing gas (c) flows into the membrane dust collector (VI) for dust removal. When the dust-containing gas (c) enters the membrane dust collector (VI), its temperature is 180° C. When the dust-containing gas c is filtered by the dust collecting membrane (4), the pressure difference across the membrane is 1500 Pa, and the gas filtration rate is 2.0 m/min. (B) The temperature and humidity sensors (1) detect the dust-containing gas entering the membrane dust collector inlet (3). When the humidity is greater than the set value, the air blower (IV) is automatically turned on to deliver anti-caking agent tricalcium phosphate stored in the anti-caking agent storage tank (V) into the anti-caking agent nozzle (2). Tricalcium phosphate has a particle size of 1,000 μm. The tricalcium phosphate is evenly ejected by the anti-caking agent nozzle (2). When the temperature is lower than the set value, the insulating and heating device (9) in the membrane dust collector (VI) is automatically turned on. (C) The dust-free gas (d) purified by the membrane dust collector (VI) is discharged from the membrane dust collector. It flows into the desulfurization tower (IX) via a one-way valve and is then vented after desulfurization. The desulfurization tower (IX) is a wet desulfurization tower, and the desulfurizer used is ammonia.

(10) After the system has run stably for 24 months, it is found that the inorganic salt in the dust collector has no agglomeration, the surface of the dust collecting membrane has no inorganic salt aggregate, the running resistance is lower than 2000 Pa, and the dust removal efficiency is higher than 99.9%.

(11) Implementation Case 3

(12) A membrane system for the treatment of the incineration tail gas of high-concentration salt-containing organic waste liquid has the same structure as implementation case 1. It has 8 anti-caking agent nozzles (2), which are arranged annularly in the membrane dust collector inlet (3). The pore board (5) has holes, the holes have a diameter of 100 mm, the distance between the centers of every two holes is 200 mm, and the dust collecting membrane (4) is installed in the holes of the pore board. The dust collecting membrane (4) is a two-layer inorganic membrane, including a support layer and a membrane layer; the support layer has a pore size of 60 μm, the membrane layer has a pore size of 3 μm, and the membrane layer has a thickness of 20 μm. The inorganic membrane has a thickness of 3 mm; the membrane material is alumina. The membrane dust collector (VI) has a backflush system.

(13) The specific operation process is as follows: (A) The high-temperature high-concentration dust-containing gas (a) discharged by the waste liquid incinerator (I) flows into the gas-solid separator (II). After part of the dust is separated, the high-temperature dust-containing gas (b) flows into the heat exchanger (III) for heat exchange. After heat exchange, the dust-containing gas (c) flows into the membrane dust collector (VI) for dust removal. When the dust-containing gas (c) enters the membrane dust collector (VI), its temperature is 800° C. When the dust-containing gas c is filtered by the dust collecting membrane (4), the pressure difference across the membrane is 3000 Pa, and the gas filtration rate is 1.5 m/min. (B) The temperature and humidity sensors (1) detect the dust-containing gas entering the membrane dust collector inlet (3). When the humidity is greater than the set value, the air blower (IV) is manually turned on to deliver anti-caking agent silica stored in the anti-caking agent storage tank (V) into the anti-caking agent nozzle (2). Silica has a particle size of 100 μm. The silica is evenly ejected by the anti-caking agent nozzle (2). When the temperature is lower than the set value, the insulating and heating device (9) in the membrane dust collector (VI) is manually turned on. (C) The dust-free gas (d) purified by the membrane dust collector (VI) is discharged from the membrane dust collector. It flows into the desulfurization tower (IX) via a one-way valve and is then vented after desulfurization. The desulfurization tower (IX) is a wet desulfurization tower, and the desulfurizer used is sodium bicarbonate.

(14) After the system has run stably for 12 months, it is found that the inorganic salt in the dust collector has no agglomeration, the surface of the dust collecting membrane has no inorganic salt aggregate, the running resistance is lower than 3500 Pa, and the dust removal efficiency is higher than 99.9%.

(15) Implementation Case 4

(16) A membrane system for the treatment of the incineration tail gas of high-concentration salt-containing organic waste liquid has the same structure as implementation case 1. It has 10 anti-caking agent nozzles (2), which are arranged annularly in the membrane dust collector inlet (3). The pore board (5) has holes, the holes have a diameter of 150 mm, the distance between the centers of every two holes is 300 mm, and the dust collecting membrane (4) is installed in the holes of the pore board. The dust collecting membrane (4) is a two-layer inorganic membrane, including a support layer and a membrane layer; the support layer has a pore size of 30 μm, and the membrane layer has a pore size of 5 μm. The inorganic membrane layer has a thickness of 20 μm. The membrane material is stainless steel. The membrane dust collector (VI) has a backflush system.

(17) The specific operation process is as follows: (A) The high-temperature high-concentration dust-containing gas (a) discharged by the waste liquid incinerator (I) flows into the gas-solid separator (II). After part of the dust is separated, the high-temperature dust-containing gas (b) flows into the heat exchanger (III) for heat exchange. After heat exchange, the dust-containing gas (c) flows into the membrane dust collector (VI) for dust removal. When the dust-containing gas (c) enters the membrane dust collector (VI), its temperature is 550° C. When the dust-containing gas c is filtered by the dust collecting membrane (4), the pressure difference across the membrane is 1800 Pa, and the gas filtration rate is 0.8 m/min. (B) The temperature and humidity sensors (1) detect the dust-containing gas entering the membrane dust collector inlet (3). When the humidity is greater than the set value, the air blower (IV) is automatically turned on to deliver anti-caking agent sodium dodecylbenzenesulfonate (SDBS) stored in the anti-caking agent storage tank (V) into the anti-caking agent nozzle (2). SDBS has a particle size of 500 μm. The SDBS is evenly ejected by the anti-caking agent nozzle (2). When the temperature is lower than the set value, the insulating and heating device (9) in the membrane dust collector (VI) is manually turned on. (C) The dust-free gas (d) purified by the membrane dust collector (VI) is discharged from the membrane dust collector. It flows into the desulfurization tower (IX) via a one-way valve and is then vented after desulfurization. The desulfurization tower (IX) is a wet desulfurization tower, and the desulfurizer used is sodium carbonate.

(18) After the system has run stably for 10 months, it is found that the inorganic salt in the dust collector has no agglomeration, the surface of the dust collecting membrane has no inorganic salt aggregate, the running resistance is lower than 2500 Pa, and the dust removal efficiency is higher than 99.9%.