Sludge heat drying treatment system

Abstract

The invention relates to the technical field of sludge treatment, in particular to a sludge heat drying treatment system which comprises a drying machine used for drying sludge entering the drying machine and generating mixed gas; the metal sintering filter is used for carrying out dust removal treatment on the sludge dry dust in the mixed gas from the drying machine; the plate heat exchanger is used for carrying out heat exchange condensation treatment on water vapor in the mixed gas subjected to dust removal treatment by the metal sintering filter and discharging condensed wastewater generated by condensation; the gas-liquid separator is used for carrying out gas-liquid separation treatment on non-condensable gas in the mixed gas subjected to heat exchange and condensation treatment by the plate heat exchanger; and the negative pressure fan is connected to the downstream of the gas-liquid separator and used for enabling the mixed gas generated by the drying machine to sequentially flow through the metal sintering filter, the plate heat exchanger and the gas-liquid separator and then be conveyed to an air feeder opening. By using the system, blocking of condensing equipment and water accumulation of an air supply pipeline caused by sludge dry dust which is not completely removed during steam condensation can be effectively avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of sludge treatment, and in particular to a sludge thermal drying treatment system. Background Art

[0002] Sludge is a heterogeneous body composed of organic debris, bacteria, inorganic particles and colloids. The traditional solution for sludge treatment is to directly pile it up and air dry it. However, since sludge is usually accompanied by a foul odor, if it is allowed to air dry naturally, it will have an impact on the surrounding environment and the air drying time is relatively long. This treatment solution has gradually failed to meet actual needs. At present, solutions based on thermal dryers, dust collectors, condensers and negative pressure fans have gradually emerged in the existing technology. Specifically, the sludge is dehydrated and dried by indirect heat exchange with the thermal dryer, and then the dried sludge is transported to the raw coal belt of the power plant for harmless co-combustion. The dry dust, steam and non-condensable air generated by the drying process are processed in turn by the dust collector and condenser under the action of the negative pressure fan. The condensed wastewater is sent to the wastewater treatment system, and the high-temperature non-condensable gas containing water is sent to the air supply duct of the power plant boiler blower. However, in actual application, it is found that existing dust collectors are usually unable to completely remove sludge dry dust. The sludge dry dust that cannot be completely removed will cause condensation equipment to be blocked when steam condenses, and the non-condensable gas carrying moisture will be partially condensed under the action of the negative pressure fan, resulting in long-term water accumulation in the air supply duct, which not only affects the air supply, but also easily corrodes the duct.

[0003] Therefore, there is an urgent need for a sludge thermal drying treatment system to solve the above problems. Summary of the Invention

[0004] The purpose of the present invention is to solve the problem in the existing technology of sludge treatment scheme based on thermal dryer, dust collector, condenser and negative pressure fan, that the dry dust of sludge that is not completely removed will cause blockage of condensation equipment during steam condensation, and the air carrying moisture is partially condensed under the action of negative pressure fan, resulting in long-term water accumulation in the air supply duct, affecting the air supply and corroding the duct, and provide a sludge thermal drying treatment system.

[0005] In order to achieve the above object, the present invention provides a sludge thermal drying treatment system, which comprises:

[0006] The dryer is used to dry the sludge entering the dryer and generate a mixed gas containing dry sludge dust, water vapor and non-condensable gas;

[0007] a metal sintered filter for removing sludge dry dust from the mixed gas from the dryer;

[0008] a plate heat exchanger for condensing the water vapor in the mixed gas after the dust removal treatment by the metal sintered filter, and transporting the condensed wastewater generated by the condensation to a wastewater treatment system;

[0009] a gas-liquid separator for performing gas-liquid separation on the non-condensable gas in the mixed gas after the heat exchange and condensation treatment by the plate heat exchanger;

[0010] A negative pressure fan is connected downstream of the gas-liquid separator, and is used to make the mixed gas generated by the dryer flow through the metal sintering filter, the plate heat exchanger and the gas-liquid separator in sequence and then be delivered to the boiler blower outlet.

[0011] Preferably, the metal sintered filter is provided with a temperature control device for making the temperature of the mixed gas entering the interior thereof higher than a set temperature value.

[0012] Preferably, the bottom inlet of the metal sintered filter is connected to the mixed gas outlet at the top of the dryer.

[0013] Preferably, the plate heat exchanger comprises:

[0014] a shell having a heat exchange cavity formed therein;

[0015] A plurality of heat exchange fins are vertically spaced apart and arranged inside the heat exchange cavity;

[0016] A cooling water inlet pipe is connected to the lower part of the inner cavity of the plurality of heat exchange fins, and is used to transport cooling water to the inner cavity of the plurality of heat exchange fins;

[0017] The cooling water outlet pipeline is connected to the upper part of the inner cavity of the plurality of heat exchange plates, and is used to output the cooling water after heat exchange and temperature increase from the inner cavity of the plurality of heat exchange plates.

[0018] Preferably, the sludge thermal drying treatment system further comprises a spraying device, which is arranged inside the heat exchange chamber and is used to flush dry dust that is not processed by the metal sintered filter and adheres to the outer surface of the heat exchange plate.

[0019] Preferably, the spraying device comprises:

[0020] A plurality of spray heads are arranged between two adjacent heat exchange fins, between the heat exchange fins and the inner side wall of the heat exchange cavity, and at the inner top of the heat exchange cavity above the heat exchange fins;

[0021] The spray water pipeline is connected to the plurality of spray heads.

[0022] Preferably, the gas-liquid separator comprises:

[0023] Cylinder;

[0024] A partition plate is horizontally arranged on the inner top of the cylinder, and is used to separate the interior of the cylinder into an upper half cylinder and a lower half cylinder;

[0025] a hollow shaft, one end of which passes through the partition plate to connect the upper and lower cylinders, and the other end of which extends vertically toward the bottom of the lower cylinder to separate the liquid phase from the gas entering the hollow cavity;

[0026] a spiral separation plate, wound around the hollow shaft, for separating the liquid phase from the gas entering the lower cylinder;

[0027] The gas-liquid separator inlet is arranged on the upper side of the lower half cylinder and connected with the end of the spiral separation plate;

[0028] The non-condensable gas outlet of the gas-liquid separator is arranged at the top of the upper half cylinder;

[0029] The wastewater outlet of the gas-liquid separator is arranged at the bottom of the lower half cylinder.

[0030] Preferably, the gas-liquid separator further comprises blades which are arranged in the hollow cavity of the hollow shaft and are rotatable under the drive of the gas.

[0031] Preferably, along the flow direction of the gas, a plurality of blades are spaced apart from bottom to top in the hollow cavity, and the sizes of the plurality of blades become larger in sequence.

[0032] Preferably, the outer surface of the blade is a frosted surface.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] 1. The sludge dry dust is first efficiently removed through a metal sintered filter, and then the water vapor is condensed by a large-channel plate heat exchanger for heat exchange. This can effectively prevent a small amount of incompletely removed sludge dry dust from clogging the plate heat exchanger when the water vapor condenses. The water in the non-condensable gas is further removed by a gas-liquid separator, and then sent into the air supply duct through a negative pressure fan. This can effectively prevent the non-condensable gas containing water from being partially condensed under the action of the negative pressure fan, causing water accumulation in the air supply duct.

[0035] 2. By installing a temperature control device on the metal sintered filter to keep its internal temperature above 100°C, water vapor can be prevented from condensing into liquid water upon cooling inside the metal sintered filter and then entering the dryer, affecting the drying efficiency. This can also prevent dry sludge dust and condensed water from mixing inside the metal sintered filter, causing bagging and affecting dust removal. Furthermore, by connecting the bottom inlet of the metal sintered filter to the mixed gas outlet at the top of the dryer, the dry sludge dust collected by the metal sintered filter can be directly discharged into the dryer via backflushing, where it can be discharged and processed together with the dried sludge, eliminating the need for separate treatment.

[0036] 3. By vertically spacing multiple heat exchange fins within the plate heat exchanger's shell and continuously flowing cooling water into the fins' inner cavities, the fins can be used to condense high-temperature steam through heat exchange. Furthermore, because the fins are spaced apart to form wide channels, even if a small amount of dry dust adheres to the fins' surfaces due to the condensed water, it is unlikely to cause blockage within a short period of time. Furthermore, by installing a spray device within the heat exchange cavity based on the wide channels to regularly flush dry dust adhering to the fins' outer surfaces, blockage of the condensation channels by dry dust can be further effectively prevented.

[0037] 4. By installing a spiral separation plate and a hollow shaft within the cylinder of the gas-liquid separator, in practical applications, the centrifugal force of the spiral can be used to achieve a primary separation of water from the non-condensable gas, followed by a secondary separation of water from the non-condensable gas due to the gravity of the hollow shaft. Furthermore, by installing rotatable blades within the hollow cavity of the hollow shaft, with multiple blades spaced from bottom to top along the gas flow direction, and with the outer surfaces of the blades being frosted, the effective separation of water from the non-condensable gas can be achieved fundamentally. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a structural diagram of the sludge thermal drying treatment system;

[0039] Figure 2 This is a schematic diagram of the structure of the gas-liquid separator of the sludge thermal drying treatment system;

[0040] Figure 3 This is a schematic diagram of the layout of the blades of the gas-liquid separator.

[0041] Description of Reference Numerals

[0042] 1. Dryer; 2. Low-pressure steam inlet; 3. Condensate outlet; 4. Wet sludge feed inlet; 5. Non-condensable gas inlet; 6. Dry sludge outlet; 7. Metal sintered filter; 8. Metal sintered filter outlet; 9. Plate heat exchanger; 10. Heat exchange chamber; 11. Heat exchange fins; 12. Plate heat exchanger inlet; 13. Plate heat exchanger condensate wastewater outlet; 14. Plate heat exchanger non-condensable gas outlet; 15. Spray water pipeline; 16. Spray head; 17. Cooling water inlet pipeline; 18. Cooling water outlet pipeline; 19. Gas-liquid separator; 191. Cylinder; 192. Partition plate; 193. Hollow shaft; 194. Spiral separation plate; 195. Blades; 20. Gas-liquid separator inlet; 21. Gas-liquid separator non-condensable gas outlet; 22. Gas-liquid separator wastewater outlet; 23. Negative pressure fan. DETAILED DESCRIPTION

[0043] The following describes in detail the specific implementation of the embodiment of the present invention. It should be understood that the specific implementation described herein is only used to illustrate and explain the embodiment of the present invention, and is not used to limit the embodiment of the present invention.

[0044] In the description of this application, "plurality" means two or more. The term "comprising" and any variations thereof mean non-exclusive inclusion, possible existence or addition of one or more other features, units, components and / or combinations thereof.

[0045] Furthermore, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly, and may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; or internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in this application based on specific circumstances.

[0046] The present invention provides a sludge thermal drying treatment system, such as Figure 1-3 As shown, the sludge thermal drying treatment system includes:

[0047] The dryer 1 is used to dry the sludge entering the dryer and generate a mixed gas containing dry sludge dust, water vapor and non-condensable gas;

[0048] The metal sintered filter 7 is used to remove the sludge dry dust in the mixed gas from the dryer 1;

[0049] The plate heat exchanger 9 is used to perform heat exchange and condensation on the water vapor in the mixed gas after the dust removal treatment by the metal sintered filter 7, and to transport the condensed wastewater generated by the condensation to the wastewater treatment system;

[0050] The gas-liquid separator 19 is used to perform gas-liquid separation on the non-condensable gas in the mixed gas after the heat exchange and condensation treatment by the plate heat exchanger 9;

[0051] The negative pressure fan 23 is connected downstream of the gas-liquid separator 19 and is used to make the mixed gas generated by the dryer 1 flow through the metal sintering filter 7, the plate heat exchanger 9 and the gas-liquid separator 9 in sequence and then be delivered to the boiler blower outlet.

[0052] According to the above technical solution, based on the sludge thermal drying treatment system, in actual application, the sludge dry dust is first efficiently removed through the metal sintered filter 7, and then the water vapor is condensed by heat exchange with the large-channel plate heat exchanger 9, which can effectively avoid a small amount of sludge dry dust that has not been completely removed from the plate heat exchanger 9 when the water vapor is condensed. After further removing the moisture in the non-condensable gas based on the gas-liquid separator 19, it is sent into the air supply duct through the negative pressure fan 23, which can effectively avoid the non-condensable gas containing moisture from being partially condensed under the action of the negative pressure fan 23, causing water accumulation in the air supply duct.

[0053] In the sludge thermal drying treatment system described in the present invention, preferably, a temperature control device is provided on the metal sintered filter 7 to make the temperature of the mixed gas entering the interior thereof higher than the set temperature value. By providing a temperature control device on the metal sintered filter 7 so that its internal temperature is higher than 100°C, it is possible to prevent water vapor from being cooled in the metal sintered filter 7 and condensed into liquid water and then entering the dryer 1, thereby affecting the drying effect of the dryer 1, and to prevent sludge dry dust and condensed water from mixing in the metal sintered filter 7, resulting in a bag-sticking phenomenon, thereby affecting the dust removal effect. Specifically, the filter cartridge of the metal sintered filter 7 is made of metal powder sintered material, and the dust concentration entering the metal sintered filter 7 from the dryer 1 is approximately 50g / Nm 3 , the dust concentration at the metal sintered filter outlet 8 is less than 10mg / Nm 3 , dust removal efficiency > 99.9%.

[0054] In another preferred embodiment, the bottom inlet of the metal sintered filter 7 is connected to the mixed gas outlet at the top of the dryer 1, so that the sludge dry dust collected by the metal sintered filter 7 can be directly discharged into the dryer 1 based on compressed air backblowing, and discharged and processed together with the dried sludge, without the need for separate treatment.

[0055] In the sludge thermal drying treatment system of the present invention, preferably, the plate heat exchanger 9 includes:

[0056] The shell has a heat exchange chamber 10 formed therein;

[0057] A plurality of heat exchange fins 11 are vertically spaced apart and arranged inside the heat exchange chamber 10;

[0058] A cooling water inlet pipe 17 is connected to the lower part of the inner cavity of the plurality of heat exchange fins 11 and is used to transport cooling water to the inner cavity of the plurality of heat exchange fins 11;

[0059] The cooling water outlet pipe 18 is connected to the upper part of the inner cavity of the plurality of heat exchange fins 11 and is used to output the cooling water after heat exchange and temperature increase out of the inner cavity of the plurality of heat exchange fins 11.

[0060] In an embodiment of the present invention, by arranging a plurality of heat exchange fins 11 at intervals in the vertical direction within the shell of the plate heat exchanger 9 and continuously introducing cooling water into the inner cavity of the heat exchange fins 11, heat exchange and condensation of high-temperature water vapor can be achieved based on the plurality of heat exchange fins 11. Moreover, since the plurality of heat exchange fins 11 are arranged at intervals to form a wide channel, even if a small amount of dry dust adheres to the surface of the heat exchange fins 11 under the action of condensed water, it is difficult to cause blockage in a short time.

[0061] Further preferably, the sludge thermal drying treatment system further includes a spraying device, which is arranged inside the heat exchange chamber 10 and is used to flush dry dust that is not processed by the metal sintered filter 7 and adheres to the outer surface of the heat exchange plate 11.

[0062] In a specific embodiment, the spraying device includes:

[0063] A plurality of spray heads 16 are arranged between two adjacent heat exchange fins 11, between the heat exchange fins 11 and the inner wall of the heat exchange chamber 10, and at the inner top of the heat exchange chamber 10 above the heat exchange fins 11;

[0064] The spray water pipeline 15 is connected to the plurality of spray heads 16 .

[0065] In an embodiment of the present invention, a spray device is provided in the heat exchange chamber 10 based on a wide channel to regularly flush dry dust attached to the outer surface of the heat exchange plate 11, thereby further effectively preventing dry dust from clogging the condensation channel.

[0066] In the sludge thermal drying treatment system of the present invention, preferably, Figure 2 As shown, the gas-liquid separator 19 includes:

[0067] Cylinder 191;

[0068] A partition plate 192 is horizontally arranged at the inner top of the cylinder 191, and is used to separate the interior of the cylinder 191 into an upper half cylinder and a lower half cylinder;

[0069] A hollow shaft 193, one end of which passes through the partition plate 192 to connect the upper and lower cylinders, and the other end of which extends vertically toward the bottom of the lower cylinder without contacting the bottom, is used to separate the liquid phase from the gas entering its hollow cavity;

[0070] A spiral separation plate 194, wound around the hollow shaft 193, is used to separate the liquid phase from the gas entering the lower cylinder;

[0071] The gas-liquid separator inlet 20 is provided on the upper side of the lower half cylinder and is connected to the end of the spiral separation plate 194;

[0072] The non-condensable gas outlet 21 of the gas-liquid separator is provided at the top of the upper half cylinder;

[0073] The gas-liquid separator wastewater outlet 22 is arranged at the bottom of the lower half cylinder.

[0074] In an embodiment of the present invention, by arranging a spiral separation plate 194 and a hollow shaft 193 in the cylinder 191 of the gas-liquid separator 19, in actual application, the water in the non-condensable gas can be separated once based on the spiral centrifugal force, and then the water in the non-condensable gas can be separated twice based on the gravity of the hollow shaft 193.

[0075] More preferably, Figure 3 As shown, the gas-liquid separator 19 further includes blades 195 which are arranged in the hollow cavity of the hollow shaft 193 and can rotate under the drive of the gas.

[0076] More preferably, along the flow direction of the gas, a plurality of blades 195 are spaced apart from bottom to top in the hollow cavity, and the sizes of the plurality of blades 195 become larger in sequence.

[0077] In an embodiment of the present invention, by further providing rotatable blades 195 within the hollow cavity of the hollow shaft 193, the moisture in the non-condensable gas can be thrown onto the inner wall of the hollow cavity based on the rotation of the blades 195, and ultimately be directed downward to the wastewater outlet 22 of the gas-liquid separator for discharge based on the action of gravity. Furthermore, by providing multiple blades 195 spaced from bottom to top along the flow direction of the gas, and by gradually increasing the size of the multiple blades 195, the barrier separation of moisture in the non-condensable gas can be achieved based on the multiple blades of different sizes arranged in a gradient, extending the action time, and thereby fundamentally achieving the separation of moisture in the non-condensable gas. Specifically, the multiple blades 195 are rotatably mounted on a support shaft arranged along the axis within the hollow cavity, and the support shaft can be supported by a support frame connected to the side of the hollow cavity.

[0078] In another preferred embodiment, the outer surface of the blade 195 is a frosted surface, so that when the blade 195 contacts the non-condensable gas, the moisture in the non-condensable gas can be better separated due to friction.

[0079] Specifically, the amount of liquid water carried in the non-condensable gas at the gas-liquid separator inlet 20 is about 200 g / Nm 3 After separation by the gas-liquid separator 19 based on the above embodiment, the amount of liquid water carried in the non-condensable gas at the non-condensable gas outlet 21 of the gas-liquid separator is less than 1 mg / Nm 3 , gas-liquid separation efficiency>99.5%, thus fundamentally avoiding water accumulation in the air supply duct.

[0080] The present invention will be described in detail below through examples, but the protection scope of the present invention is not limited thereto.

[0081] Example 1

[0082] Use Figure 1-3 The sludge thermal drying treatment system shown is used for drying sludge. Specifically, the sludge thermal drying treatment system includes:

[0083] The dryer 1 is used to dry the sludge entering the dryer and generate a mixed gas containing dry sludge dust, water vapor and non-condensable gas;

[0084] The metal sintered filter 7 is used to remove the sludge dry dust in the mixed gas from the dryer 1;

[0085] The plate heat exchanger 9 is used to perform heat exchange and condensation on the water vapor in the mixed gas after the dust removal treatment by the metal sintered filter 7, and to transport the condensed wastewater generated by the condensation to the wastewater treatment system;

[0086] The gas-liquid separator 19 is used to perform gas-liquid separation on the non-condensable gas in the mixed gas after the heat exchange and condensation treatment by the plate heat exchanger 9;

[0087] A negative pressure fan 23 is connected downstream of the gas-liquid separator 19 and is used to make the mixed gas generated by the dryer 1 flow through the metal sintered filter 7, the plate heat exchanger 9 and the gas-liquid separator 19 in sequence and then be delivered to the boiler blower outlet;

[0088] Specifically, the metal sintered filter 7 is provided with a temperature control device for making the temperature of the mixed gas entering it higher than 100°C, specifically 110°C; the bottom inlet of the metal sintered filter 7 is connected to the mixed gas outlet at the top of the dryer 1; the plate heat exchanger 9 includes: a shell, with a heat exchange cavity 10 formed therein; a plurality of heat exchange fins 11, arranged at intervals in the vertical direction inside the heat exchange cavity 10; a cooling water inlet pipe 17, connected to the lower part of the inner cavity of the plurality of heat exchange fins 11, for transporting cooling water to the inner cavity of the plurality of heat exchange fins 11; a cooling water outlet pipe 18, connected to the upper part of the inner cavity of the plurality of heat exchange fins 11, for outputting the cooling water after heat exchange and temperature increase out of the inner cavity of the plurality of heat exchange fins 11.

[0089] In actual use, wet sludge enters the disc dryer 1 through the wet sludge feed inlet 4. The disc dryer 1 has two low-pressure steam inlets 2, a condensate outlet 3, and a non-condensable gas inlet 5. After the wet sludge undergoes heat exchange drying in the disc dryer 1, the dry sludge is discharged through the dry sludge outlet 6 of the disc dryer 1. The non-condensable gas, or air, enters the disc dryer 1 under the negative pressure of the negative pressure blower 23. This air is used to carry the evaporated water out of the disc dryer 1 as water vapor. As the disc dryer 1 dries the wet sludge, the moisture content gradually decreases. Under the action of the negative pressure blower 23, the dry sludge dust, evaporated water vapor, and air enter the metal sintered filter 7. The metal sintered filter 7 is fixed directly above the disc dryer 1 and rigidly connected to the disc dryer 1 via a flange. The filter cartridge of the metal sintered filter 7 is made of sintered metal powder. The metal sintered filter outlet 8 of the metal sintered filter 7 is connected to the plate heat exchanger inlet 12 via a connecting pipe. The plate heat exchanger 9 uses plate-type heat exchange fins 11 for indirect heat exchange. The plate heat exchanger 9 is equipped with a circulating cooling water inlet pipe 17 and a circulating cooling water outlet pipe 18. Water vapor, air, and uncollected dry sludge dust at a temperature of approximately 110°C enter the plate heat exchanger 9 through the plate heat exchanger inlet 12. The 110°C water vapor and circulating cooling water undergo indirect heat exchange. The circulating cooling water enters through the circulating cooling water inlet pipe 17. After heat exchange, the heated circulating cooling water is discharged through the circulating cooling water outlet pipe 18. Dry sludge dust that is not filtered out by the metal sintered filter 7 enters the plate heat exchanger 9 and adheres to the surface of the heat exchange fins 11 of the plate heat exchanger 9. The evaporated water vapor is condensed into liquid water through the plate heat exchanger 9. The condensed liquid water and flushing water are discharged into the wastewater treatment system through the plate heat exchanger condensation wastewater outlet 13. After passing through the metal sintered filter 7 and the plate heat exchanger 9, the dry sludge dust and evaporated water vapor are collected and condensed. The non-condensable air entering through the non-condensable gas inlet 5 enters the gas-liquid separator 19 through the plate heat exchanger non-condensable gas outlet 14 of the plate heat exchanger 9, the connecting pipe, and the gas-liquid separator inlet 20. After passing through the plate heat exchanger 9, the air, under the action of the negative pressure fan 23, will carry a certain amount of liquid water droplets into the gas-liquid separator 19. The gas-liquid separator 19 removes these liquid water droplets and discharges the collected liquid water into the wastewater treatment system through the gas-liquid separator wastewater outlet 22. The non-condensable air enters the negative pressure fan 23 through the non-condensable gas outlet 21 of the gas-liquid separator and the connecting pipe, and is sent to the outlet of the boiler blower of the power plant through the negative pressure fan 23 and the exhaust pipe.

[0090] The sludge thermal drying treatment system described in the present invention is used. In actual application, the sludge dry dust is first efficiently removed through a metal sintered filter, and then the water vapor is condensed by heat exchange with a large-channel plate heat exchanger, which can effectively prevent a small amount of sludge dry dust that has not been completely removed from causing blockage of the plate heat exchanger when the water vapor is condensed. The moisture in the non-condensable gas is further removed based on the gas-liquid separator, and then sent into the air supply duct through the negative pressure fan, which can effectively prevent the non-condensable gas containing moisture from being partially condensed under the action of the negative pressure fan, causing water accumulation in the air supply duct; by providing a temperature control device on the metal sintered filter to make its internal temperature 110°C, it can be avoided that the water vapor is cooled in the metal sintered filter and condensed into liquid water and then enters the dryer, affecting the drying effect of the dryer, and the sludge dry dust and condensed water are mixed in the metal sintered filter, resulting in a sticky bag phenomenon, which affects the dust removal effect. Furthermore, by connecting the bottom inlet of the metal sintered filter with the mixed gas outlet at the top of the dryer, the dry sludge dust collected by the metal sintered filter can be directly discharged into the dryer based on backblowing, and discharged and processed together with the dried sludge without the need for separate treatment; by arranging multiple heat exchange fins at intervals in the vertical direction in the shell of the plate heat exchanger and continuously introducing cooling water into the inner cavity of the heat exchange fins, heat exchange and condensation of high-temperature water vapor can be achieved based on the multiple heat exchange fins, and since the multiple heat exchange fins are arranged at intervals to form a wide channel, even if a small amount of dry dust adheres to the surface of the heat exchange fins under the action of condensed water, it is difficult to cause blockage in a short time.

[0091] Example 2

[0092] Refer to Example 1, except that the sludge thermal drying treatment system further includes a spraying device, which is arranged inside the heat exchange chamber 10 and is used to flush dry dust that has not been processed by the metal sintered filter 7 and is attached to the outer surface of the heat exchange plate 11; the spraying device includes: a plurality of spray heads 16, which are arranged between two adjacent heat exchange plates 11, between the heat exchange plate 11 and the inner side wall of the heat exchange chamber 10, and at the inner top of the heat exchange chamber 10 above the heat exchange plate 11; and a spray water pipeline 15, which is connected to the plurality of spray heads 16.

[0093] Compared with the solution in Example 1, the sludge thermal drying treatment system described in the present invention provides a spraying device in the heat exchange chamber based on a wide channel to regularly flush dry dust attached to the outer surface of the heat exchange plate, which can further effectively prevent dry dust from clogging the condensation channel.

[0094] Example 3

[0095] Refer to Example 2 for implementation, except that the gas-liquid separator 19 includes: a cylinder 191; a partition plate 192, horizontally arranged at the inner top of the cylinder 191, for dividing the interior of the cylinder 191 into an upper cylinder and a lower cylinder; a hollow shaft 193, one end of which passes through the partition plate 192 to connect the upper cylinder and the lower cylinder, and the other end of which extends vertically toward the bottom of the lower cylinder, for separating the liquid phase in the gas entering its hollow cavity; a spiral separation plate 194, wound around the hollow shaft 193, for separating the liquid phase in the gas entering the lower cylinder; The liquid separator inlet 20 is arranged on the upper side of the lower half of the cylinder and is connected with the end of the spiral separation plate 194; the non-condensable gas outlet 21 of the gas-liquid separator is arranged at the top of the upper half of the cylinder; the waste water outlet 22 of the gas-liquid separator is arranged at the bottom of the lower half of the cylinder; the gas-liquid separator 19 also includes a blade 195 arranged in the hollow cavity of the hollow shaft 193 and rotatable under the drive of the gas; along the flow direction of the gas, three blades 195 are arranged in the hollow cavity from bottom to top, and the sizes of the three blades 195 become larger in sequence; the outer surface of the blade 195 is a frosted surface.

[0096] The sludge thermal drying treatment system of the present invention is compared with the solution in Example 2. By arranging a spiral separation plate and a hollow shaft in the cylinder of the gas-liquid separator, in actual application, the water in the non-condensable gas can be separated once based on the spiral centrifugal force, and then the water in the non-condensable gas can be separated twice based on the gravity of the hollow shaft. Furthermore, by arranging rotatable blades in the hollow cavity of the hollow shaft; along the gas flow direction, a plurality of blades are arranged in the hollow cavity from bottom to top, and the sizes of the plurality of blades are successively larger; and the outer surface of the blade is a frosted surface, which can fundamentally realize the separation of water in the non-condensable gas. Specifically, the dust concentration entering the metal sintered filter 7 from the dryer 1 is about 50g / Nm 3 , the dust concentration at the metal sintered filter outlet 8 is less than 10mg / Nm 3 , dust removal efficiency> 99.9%; the amount of liquid water carried in the non-condensable gas at the gas-liquid separator inlet 20 is about 200g / Nm 3 The amount of liquid water carried in the non-condensable gas at the non-condensable gas outlet 21 of the gas-liquid separator is less than 1 mg / Nm 3 , gas-liquid separation efficiency > 99.5%.

[0097] The sludge thermal drying treatment system provided by the present invention first efficiently removes sludge dry dust through a metal sintered filter, and then cooperates with a large-channel plate heat exchanger to condense water vapor for heat exchange, which can effectively prevent a small amount of incompletely removed sludge dry dust from causing blockage of the plate heat exchanger when the water vapor condenses. After further removing moisture from the non-condensable gas based on the gas-liquid separator, it is then sent into the air supply duct through a negative pressure fan, which can effectively prevent the non-condensable gas containing moisture from being partially condensed under the action of the negative pressure fan, causing water accumulation in the air supply duct.

[0098] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical scope of the present invention, various simple variations of the technical solution of the present invention may be made. To avoid unnecessary repetition, the present invention will not further describe various possible combinations. However, these simple variations and combinations should also be considered as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. A sludge thermal drying treatment system, characterized in that: The sludge thermal drying treatment system comprises: A dryer (1) is used to dry the sludge entering the dryer and generate a mixed gas containing dry sludge dust, water vapor and non-condensable gas; A metal sintered filter (7) for removing sludge dry dust from the mixed gas from the dryer (1); a plate heat exchanger (9) for performing heat exchange and condensation treatment on the water vapor in the mixed gas after the dust removal treatment by the metal sintered filter (7), and for conveying the condensed wastewater generated by the condensation to a wastewater treatment system; A gas-liquid separator (19) is used for performing gas-liquid separation on the non-condensable gas in the mixed gas after the heat exchange and condensation treatment in the plate heat exchanger (9); A negative pressure fan (23) is connected downstream of the gas-liquid separator (19) and is used to allow the mixed gas generated by the dryer (1) to flow through the metal sintered filter (7), the plate heat exchanger (9) and the gas-liquid separator (19) in sequence and then be transported to the boiler blower outlet.

2. The sludge thermal drying treatment system according to claim 1, characterized in that: The metal sintered filter (7) is provided with a temperature control device for making the temperature of the mixed gas entering the metal sintered filter higher than a set temperature value.

3. The sludge thermal drying treatment system according to claim 2, characterized in that: The bottom inlet of the metal sintered filter (7) is communicated with the mixed gas outlet at the top of the dryer (1).

4. The sludge thermal drying treatment system according to any one of claims 1 to 3, characterized in that: The plate heat exchanger (9) comprises: A shell having a heat exchange cavity (10) formed therein; A plurality of heat exchange fins (11) are arranged at intervals in a vertical direction inside the heat exchange cavity (10); A cooling water inlet pipe (17) is communicated with the lower portion of the inner cavity of the plurality of heat exchange fins (11) and is used to transport cooling water into the inner cavity of the plurality of heat exchange fins (11); The cooling water outlet pipe (18) is connected to the upper part of the inner cavity of the plurality of heat exchange plates (11) and is used to output the cooling water after heat exchange and temperature increase to the inner cavity of the plurality of heat exchange plates (11).

5. The sludge thermal drying treatment system according to claim 4, characterized in that: The sludge thermal drying treatment system further comprises a spraying device, which is arranged inside the heat exchange chamber (10) and is used to flush dry dust that is not processed by the metal sintered filter (7) and adheres to the outer surface of the heat exchange plate (11).

6. The sludge thermal drying treatment system according to claim 5, characterized in that: The spraying device comprises: A plurality of spray heads (16) are arranged between two adjacent heat exchange fins (11), between the heat exchange fins (11) and the inner side wall of the heat exchange cavity (10), and at the inner top of the heat exchange cavity (10) above the heat exchange fins (11); The spray water pipeline (15) is connected to the plurality of spray heads (16).

7. The sludge thermal drying treatment system according to claim 1, characterized in that: The gas-liquid separator (19) comprises: Cylinder (191); A partition plate (192) is horizontally arranged on the inner top of the cylinder (191) and is used to separate the interior of the cylinder (191) into an upper half cylinder and a lower half cylinder; A hollow shaft (193), one end of which passes through the partition plate (192) to connect the upper half cylinder and the lower half cylinder, and the other end of which extends vertically toward the bottom of the lower half cylinder to separate the liquid phase of the gas entering the hollow cavity thereof; a spiral separation plate (194), wound around the hollow shaft (193), for separating the liquid phase from the gas entering the lower cylinder; The gas-liquid separator inlet (20) is arranged on the upper side of the lower half cylinder and is connected to the end of the spiral separation plate (194); A non-condensable gas outlet (21) of the gas-liquid separator is provided at the top of the upper half cylinder; The gas-liquid separator wastewater outlet (22) is arranged at the bottom of the lower half cylinder.

8. The sludge thermal drying treatment system according to claim 7, characterized in that: The gas-liquid separator (19) further includes blades (195) which are arranged in the hollow cavity of the hollow shaft (193) and are rotatable under the drive of the gas.

9. The sludge thermal drying treatment system according to claim 8, characterized in that: Along the flow direction of the gas, a plurality of blades (195) are arranged at intervals from bottom to top in the hollow cavity, and the sizes of the plurality of blades (195) gradually increase.

10. The sludge thermal drying treatment system according to claim 8 or 9, characterized in that: The outer surface of the blade (195) is a frosted surface.

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