Sludge dehydration, drying and denitrification integrated equipment and process

Abstract

The present invention provides a sludge dehydration, drying and denitrification integrated equipment, including: a dehydration, drying and denitrification integrated machine; a filter press water tank; a denitrification system, including a condenser, an alkali adding device and a first gas-liquid separation device, the liquid inlet of the condenser is connected to the total liquid outlet of the dehydration, drying and denitrification integrated machine through a pipeline, the liquid outlet of the condenser is connected to the first gas-liquid separation device through a pipeline, and the alkali adding device is connected to the total liquid inlet of the dehydration, drying and denitrification integrated machine through an alkali adding pipeline; a nitrogen fixation system, including a pickling device for reacting ammonia to generate ammonium sulfate mother liquor, the pickling device is connected to the first gas-liquid separation device, and the pickling device is connected to a vacuum pump. The present invention also provides a sludge dehydration, drying and denitrification process. The present invention changes the traditional dehydration and drying process flow, adds a denitrification system and a nitrogen fixation system, and can simultaneously carry out denitrification in the dehydration and drying stages, reacts the escaped ammonia to generate ammonium sulfate mother liquor, and subsequently performs evaporation, crystallization and drying processes to generate ammonium sulfate products.

Description

Technical Field

[0001] The present invention relates to the field of sludge treatment, and in particular to a sludge dehydration, drying and denitrification integrated equipment and process. Background Art

[0002] Drying materials with high water content has always been a major problem. The process flow is numerous and complicated. For example, the disposal of sludge requires multiple independent process flows. In addition, traditional drying equipment and dehydration equipment are separated and occupy a large area. At the same time, the conversion between dehydration and drying requires time and labor, which increases the pressure on environmental protection and safety. In addition, with the improvement of the quality requirements for sludge treatment, it is necessary to recycle the valuable nitrogen resources in the sludge, so it is necessary to take denitrification measures. How to design a simple and easy-to-use equipment to dehydrate, dry and denitrify materials with high water content is a problem that technicians in this field need to solve. Summary of the invention

[0003] The first technical problem to be solved by the present invention is to provide an integrated mud dehydration, drying and denitrification device to overcome the above-mentioned defects of the prior art.

[0004] To achieve the above object, the present invention provides a sludge dehydration, drying and denitrification integrated equipment, comprising:

[0005] The dehydration, drying and denitrification integrated machine comprises a plurality of filter plates and filter press heating plates, wherein the filter plates and the filter press heating plates are arranged alternately, the filter plates are provided with a first liquid outlet, and the filter press heating plates are provided with a second liquid inlet and a second liquid outlet;

[0006] A filter press water tank, wherein the filter press water tank is provided with a heating water supply pipe, a heating water return pipe, a squeezing water supply pipe and a squeezing water return pipe, wherein the heating water supply pipe and the squeezing water supply pipe are respectively connected to the second liquid inlet, and the heating water return pipe and the squeezing water return pipe are respectively connected to the second liquid outlet;

[0007] A denitrification system, comprising a condenser, an alkali adding device and a first gas-liquid separation device, wherein the liquid inlet of the condenser is connected to the total liquid outlet of the dehydration, drying and denitrification integrated machine through a pipeline, the liquid outlet of the condenser is connected to the first gas-liquid separation device through a pipeline, and the alkali adding device is connected to the total liquid inlet of the dehydration, drying and denitrification integrated machine through an alkali adding pipeline;

[0008] The nitrogen fixation system comprises a pickling device for reacting ammonia gas to generate ammonium sulfate mother liquor, the pickling device is connected to the first gas-liquid separation device, and the pickling device is connected to a vacuum pump.

[0009] Preferably, the pickling equipment includes an acid adding device, a pickling tower and a buffer tank, the acid adding device is connected to the pickling tower, the first gas-liquid separation device is connected to the pickling tower, the top outlet of the pickling tower is connected to the buffer tank, the buffer tank is connected to a vacuum pump, and the pickling tower is also provided with a liquid outlet connected to the ammonium sulfate productization system.

[0010] Preferably, the ammonium sulfate productization system includes a mother liquid storage tank, a second gas-liquid separation device, a compressor, a preheater, a heater and an evaporator, the liquid outlet of the mother liquid storage tank is connected to the liquid inlet of the preheater, the liquid outlet of the preheater is connected to the liquid inlet of the heater, and the liquid outlet of the heater is connected to the liquid inlet of the evaporator; the steam outlet of the evaporator is connected to the heater, and a compressor is also provided on the pipeline connecting the steam outlet of the evaporator and the heater, the water outlet of the heater is connected to the water inlet of the preheater, and the water outlet of the preheater is connected to the second gas-liquid separation device; the air inlet of the buffer tank is connected to the second gas-liquid separation device.

[0011] Preferably, the ammonium sulfate productization system also includes a cooling crystallization system and a drying system. The cooling crystallization equipment includes a cooling crystallization tank, a centrifuge and a filtrate storage tank. The liquid inlet of the cooling crystallization tank is connected to the liquid outlet of the evaporator, the cooling crystallization tank is connected to the centrifuge, the centrifuge is connected to a conveying device, and the conveying device is connected to the drying system.

[0012] Preferably, a feeding system is included, and the feeding system includes a sludge conditioning tank, and the sludge conditioning tank is connected to the feeding port of the dehydration, drying and denitrification integrated machine through a feeding pipe, and a feeding pump is provided on the feeding pipe.

[0013] Preferably, a reflux pipe is provided on the feed pipe, and the reflux pipe is connected to the sludge conditioning tank.

[0014] Preferably, the heating water supply pipe is provided with a hot water pump, and the pressing water supply pipe is provided with a filter press pump.

[0015] Preferably, the filter press water tank is connected to the hot water boiler via a hot water pipeline, and a hot water circulation pump is provided on the hot water pipeline.

[0016] Preferably, the alkali adding pipeline is provided with an alkali adding branch pipe, and the alkali adding branch pipe is connected to the first gas-liquid separation device.

[0017] The second technical problem to be solved by the present invention is to provide a mud dehydration, drying and denitrification process, comprising the following steps:

[0018] Dehydration step: the material is sent into the dehydration, drying and denitrification integrated machine. After the material is dehydrated by the filter plate, a filter cake is formed in the middle chamber between the filter plate and the filter press heating plate;

[0019] Drying step: When the filter cake is in the middle chamber, turn on the hot water pump to pump hot water into the filter press heating plate to heat the filter cake, so that the water in the filter cake can be vaporized and escape;

[0020] Denitrification step: in the dehydration stage, the alkali adding device adds alkali solution to the filter plate, ammonia escapes, and is sent to the first gas-liquid separation device after condensation by the condenser, and the alkali solution is added to adjust the pH value so that the ammonia escapes to the nitrogen fixation system again; in the drying stage, ammonia is extracted from the dehydration, drying and denitrification integrated machine, and is sent to the first gas-liquid separation device after condensation by the condenser, and the alkali solution is added to adjust the pH value so that the ammonia escapes to the nitrogen fixation system again.

[0021] Preferably, in the dehydration stage, when the feed pump reaches a preset pressure, the feed is stopped, and the filter press pump is turned on to pump high-pressure hot water into the filter press heating plate to press the filter cake, thereby further reducing the moisture content of the filter cake.

[0022] Preferably, the method further comprises the following ammonium sulfate product production steps: the mother liquor enters the mother liquor storage tank from the pickling tower for storage, enters the heater after heat exchange in the preheater, and then enters the evaporator for evaporation and concentration, and the concentrated liquid is discharged from the discharge liquid port of the evaporator to the cooling crystallization system for crystallization; the secondary steam is discharged from the evaporator, and enters the heater for heating after pressure and temperature are increased by the compressor, and then the condensed water flows by gravity to the preheater for heating, flows into the second gas-liquid separation device, and the condensed water is discharged from the second gas-liquid separation device.

[0023] As described above, the integrated sludge dehydration, drying and denitrification equipment and process involved in the present invention has the following beneficial effects: the present invention changes the traditional dehydration and drying process flow, adds a denitrification system and a nitrogen fixation system, and can simultaneously carry out denitrification in the dehydration and drying stages, reacting the escaped ammonia gas to generate ammonium sulfate mother liquor, and subsequently performing evaporation, crystallization and drying processes to generate ammonium sulfate products. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a system schematic diagram of the present invention.

[0025] Figure 2 This is a schematic diagram of the structure of the dehydration, drying and denitrification integrated machine.

[0026] Figure 3 It is a structural schematic diagram of the filter press heating plate.

[0027] Figure 4 Schematic diagram of the structure of the filter plate.

[0028] Figure 5 This is a system schematic diagram of the ammonium sulfate productization system.

[0029] Component number description

[0030] 1 Dehydration, drying and denitrification integrated machine

[0031] 11 Filter Plate

[0032] 111 First liquid outlet

[0033] 12 Filter press heating plate

[0034] 121 Second liquid inlet

[0035] 122 Second liquid outlet

[0036] 13. Intermediate chamber

[0037] 2 filter press water tank

[0038] 21 Heating water pipe

[0039] 211 Hot water pump

[0040] 22 Heating return pipe

[0041] 23 Squeeze water pipe

[0042] 231 Filter Press Pump

[0043] 24 Press return pipe

[0044] 25 Hot water circulation pump

[0045] 3 Denitrification system

[0046] 31 Condenser

[0047] 32 Alkali adding device

[0048] 321 Alkali adding pipeline

[0049] 322 Alkali Addition

[0050] 33. The first gas-liquid separation device

[0051] 4 Nitrogen Fixation System

[0052] 41 Acidification device

[0053] 42 Pickling Tower

[0054] 421 Spraying device

[0055] 422 demister

[0056] 423 Ammonium sulfate mother liquor tank

[0057] 43 Buffer tank

[0058] 5 Vacuum pump

[0059] 6 Feeding system

[0060] 61 Sludge conditioning tank

[0061] 62 Feed pipe

[0062] 63 Feed pump

[0063] 64 Return pipe

[0064] 7 Ammonium sulfate productization system

[0065] 71 Mother liquor storage tank

[0066] 711 Mother liquor feed pump

[0067] 72 Second gas-liquid separation device

[0068] 721 Coolant Pump

[0069] 73 Compressor

[0070] 74 Preheater

[0071] 741 Mother liquor circulation pump

[0072] 75 Heater

[0073] 76 Evaporator

[0074] 761 Discharging Department

[0075] 771 Cooling crystallization tank

[0076] 772 Centrifuge

[0077] 773 Filtrate Storage Tank

[0078] 774 Filtrate Reflux Pump

[0079] 78 Conveying equipment

[0080] 791 Drying tube

[0081] 792 Cyclone Separator

[0082] 793 Bag Dust Collector

[0083] 794 induced draft fan

[0084] 795 Air Heater

[0085] 796 Blower DETAILED DESCRIPTION

[0086] The following is a description of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0087] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and so on quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of the relative relationship should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0088] like Figures 1 to 4 As shown, the present invention provides a sludge dehydration, drying and denitrification integrated equipment, including a dehydration, drying and denitrification integrated machine 1, a filter press water tank 2, a denitrification system 3, a nitrogen fixation system 4, a vacuum system and a feeding system 6.

[0089] The dehydration, drying and denitrification integrated machine 1 comprises a plurality of filter plates 11 and filter press heating plates 12, the filter plates 11 and the filter press heating plates 12 are arranged alternately, the four corners of the filter plate 11 are respectively provided with a first liquid outlet 112, the four corners of the filter press heating plate 12 are provided with holes, which are a pair of second liquid inlets 121 and a pair of second liquid outlets 122 respectively, and the dehydration, drying and denitrification integrated machine 1 is also provided with a total liquid inlet and a total liquid outlet; a middle hole for feeding is provided in the middle of the dehydration, drying and denitrification integrated machine 1; an intermediate chamber 15 is provided in the middle area of ​​the filter plate 11 and the filter press heating plate 12, which is used to form the material into a filter cake.

[0090] The filter press water tank 2 is provided with a heating water supply pipe 21, a heating water return pipe 22, a squeezing water supply pipe 23 and a squeezing water return pipe 24. The heating water supply pipe 21 and the squeezing water supply pipe 23 are respectively connected to the second liquid inlet 121 of the filter press heating plate 12, and the heating water return pipe 22 and the squeezing water return pipe 24 are respectively connected to the second liquid outlet 122 of the filter press heating plate 12. In the dehydration stage, high-pressure hot water is pumped into the filter press heating plate 12 through the squeezing water supply pipe 23 to squeeze the filter cake, reduce the water content of the filter cake, and return the hot water to the filter press water tank 2 through the squeezing water return pipe 24; in the drying stage, hot water is pumped into the filter press heating plate 12 through the heating water supply pipe 21 to heat the filter cake, so that the water in the filter cake is vaporized and escapes, and the hot water is returned to the filter press water tank 2 through the heating water return pipe 22.

[0091] The denitrification system 3 is used to remove ammonia from the filtrate in the dehydration stage and the drying stage. The denitrification system 3 includes a condenser 31, an alkali adding device 32 and a first gas-liquid separation device 33. The liquid inlet of the condenser 31 is connected to the total liquid outlet of the dehydration, drying and denitrification integrated machine 1 through a pipeline, and the liquid outlet of the condenser 31 is connected to the first gas-liquid separation device 33 through a vacuum pipeline. The alkali adding device 32 is connected to the total liquid inlet of the dehydration, drying and denitrification integrated machine 1 through an alkali adding pipeline 321. The alkali adding device 32 is configured with 10% alkali solution and can adopt a self-priming structure. When the flow rate is insufficient, a flow pump can be used to send the alkali solution to the dehydration, drying and denitrification integrated machine 1 to mix it evenly with the water filtrate of the filter plate 11. During the dehydration stage, the alkali solution from the alkali adding device 32 enters the total liquid inlet of the dehydration, drying and denitrification integrated machine 1 and is evenly mixed with the effluent filtrate in the filter plate 11. Due to the increase in pH value and temperature, ammonia containing a portion of water enters the condenser 31 through the vacuum pipeline and is condensed to the first gas-liquid separation device 33. Alkali solution is added to adjust the pH value to allow the ammonia to escape again.

[0092] The nitrogen fixation system 4 includes a pickling device for reacting ammonia to generate ammonium sulfate mother liquor, and the pickling device is connected to the first gas-liquid separation device 33. The vacuum pumping system includes a vacuum pump 5, and the pickling device is connected to the vacuum pump 5, that is, the vacuum pump 5 vacuumizes the pickling device, the condenser 31, and the dehydration, drying and denitrification integrated machine 1, thereby providing a vacuum environment for the vacuum drying system and the denitrification system at the same time.

[0093] like Figure 1As shown, preferably, the pickling equipment includes an acid adding device 41, a pickling tower 42 and a buffer tank 43, the pickling tower 42 includes an ammonium sulfate mother liquor pool 423, a spraying device 421 and a demister 422 arranged in sequence from bottom to top in the tower body, the acid adding device 41 is connected to the spraying device 421 of the pickling tower 42, the acid adding device 41 is configured with 30% sulfuric acid, and self-absorbs into the pickling tower; an ammonia inlet is also provided on the tower wall of the pickling tower 42, the first gas-liquid separation device 33 is connected to the ammonia inlet of the pickling tower 42 through a vacuum pipeline, and the ammonia is transported to the pickling tower In the tower 42, the top outlet of the pickling tower 42 is connected to the buffer tank 43 through a vacuum pipeline, and the buffer tank 43 is connected to the vacuum pump 5. The pickling tower 42 is also provided with a liquid outlet connected to the ammonium sulfate productization system. The liquid outlet is located at the bottom of the pickling tower 42, and the liquid outlet can also be connected to the spray device 421. If the pH value of the ammonium sulfate solution is too low, the ammonium sulfate solution can be transported to the spray device 421 for spraying to continue to react with ammonia. The buffer tank 43 can also be connected to the ammonium sulfate productization system through a pipeline, so as to evacuate the ammonium sulfate productization system. Sulfuric acid is self-absorbed into the pickling tower through the acid adding device 41 and sprayed through the spray device 421. The ammonia gas coming out of the denitrification system is connected to the bottom of the pickling tower 42 and reacts in countercurrent with the sulfuric acid sprayed by the spray device 421 in the packing part of the pickling tower 42. The ammonium sulfate mother liquor generated after the reaction is pumped to the nitrogen productization system from the bottom outlet of the pickling tower 42 through the mother liquor discharge pump. Of course, if the pH value of the ammonium sulfate mother liquor is too low, the ammonium sulfate solution can be transported to the spray device 421 for spraying to continue to react with the ammonia gas. The gas-liquid mixture in the top of the pickling tower 42 is transported to the buffer tank 43 for storage.

[0094] like Figure 1 As shown, preferably, the feeding system 6 includes a sludge conditioning tank 61, and the sludge conditioning tank 61 is connected to the feed port of the dehydration, drying and denitrification integrated machine 1 through a feed pipe 62, and a feed pump 63 is provided on the feed pipe 62, and the sludge is pumped into the feed port of the dehydration, drying and denitrification integrated machine 1 through the feed pump 63. Preferably, a return pipe 64 is provided on the feed pipe 62, and the return pipe 64 is connected to the sludge conditioning tank 61, and the return pipe 64 is connected in parallel with the feed pump 63. When the dehydration, drying and denitrification process is completed, there is still a part of the material in the feed pipe 62, which can be returned to the sludge conditioning tank 61 through the return pipe 64.

[0095] like Figure 1 As shown, preferably, a hot water pump 211 is provided on the heating water supply pipe 21, and a filter press pump 231 is provided on the pressing water supply pipe 23. Preferably, the filter press water tank 2 is connected to the hot water boiler through a hot water pipeline, and a hot water circulation pump 25 is provided on the hot water return pipeline to deliver the hot water in the filter press water tank 2 to the hot water boiler.

[0096] like Figure 1As shown, preferably, the alkali adding pipeline 321 is provided with an alkali adding branch pipe 322, and the alkali adding branch pipe 322 is connected to the first gas-liquid separation device 33, so as to facilitate adding alkali liquid into the first gas-liquid separation device 33 to adjust the pH value in the first gas-liquid separation device 33.

[0097] like Figure 5 As shown, preferably, the ammonium sulfate productization system 7 includes a mother liquid storage tank 71, a second gas-liquid separation device 72, a compressor 73, a preheater 74, a heater 75 and an evaporator 76, the liquid outlet of the mother liquid storage tank 71 is connected to the liquid inlet of the preheater 74, the liquid outlet of the preheater 74 is connected to the liquid inlet of the heater 75, the pipeline connecting the liquid outlet of the preheater 74 and the liquid inlet of the heater 75 is provided with a mother liquid circulation pump 741, the liquid outlet of the evaporator 76 is provided with a mother liquid circulation pump 741 connected to the preheater 74 and the mother liquid circulation pump 741. The pipeline between the pumps 741 is connected to the branch pipeline, the liquid outlet of the heater 75 is connected to the liquid inlet of the evaporator 76; the steam outlet of the evaporator 76 is connected to the heater 75, and the pipeline connecting the steam outlet of the evaporator 76 and the heater 75 is also provided with a compressor 73, the water outlet of the heater 75 is connected to the water inlet of the preheater 74, and the water outlet of the preheater 74 is connected to the second gas-liquid separation device 72; the air inlet of the buffer tank 43 is connected to the second gas-liquid separation device 72. The ammonium sulfate productization system 7 also includes a cooling crystallization system, and the cooling crystallization equipment includes a cooling crystallization tank 771, a centrifuge 772 and a filtrate storage tank 773, the liquid inlet of the cooling crystallization tank 771 is connected to the liquid outlet of the evaporator 76, the cooling crystallization tank 771 is connected to the centrifuge 772, the centrifuge 772 is connected to the conveying equipment 78, and the conveying equipment 78 is connected to the drying system.

[0098] The mother liquid enters the mother liquid storage tank 71 from the bottom outlet of the pickling tower 42 for storage, passes through the mother liquid feed pump 711, enters the mother liquid feed pump 711 circulation pipeline after heat exchange in the preheater 74, then enters the heater 75 for heating and enters the evaporator 76; a part of the mother liquid in the evaporator 76 is discharged, and continues to circulate to the evaporator 76 after heat exchange through the mother liquid circulation pump 741 and the heater 75, and evaporates and concentrates in the evaporator 76 to generate concentrated liquid and secondary steam. The secondary steam is discharged from the evaporator 76, compressed by the compressor 73, and the pressure and temperature increase, and the thermal enthalpy increases, and then sent to the heating chamber entering the heater 75 to be used as heating steam to heat the circulating mother liquid, and the heating steam itself condenses into water, and then the condensed water flows to the preheater 74 for heating, and flows into the second gas-liquid separation device 72, and the condensed water is discharged from the second gas-liquid separation device 72 through the coolant pump 721. The concentrated liquid is discharged from the discharge port of the evaporator 76 to the cooling crystallization tank 771 for cooling and crystallization, and then the ammonium sulfate crystals are separated by the centrifuge 772, and the filtrate is discharged to the filtrate storage tank 773, and then discharged to the mother liquid storage tank 71 through the filtrate reflux pump; the secondary steam is discharged from the evaporator 76, and after the compressor 73 increases the pressure and temperature, it enters the heater 75 for heating, and then the condensed water flows to the preheater 74 for heating, flows into the second gas-liquid separation device 72, and the condensed water is discharged from the coolant pump 721. In addition, the air inlet of the buffer tank 43 is connected to the second gas-liquid separation device 72, so that the second gas-liquid separation device 72, the preheater 74, the heater 75, and the evaporator 76 are evacuated by the vacuum pump 5, so that the vacuum pump can provide a vacuum environment for the vacuum drying system, the denitrification system, and the ammonium sulfate productization system at the same time.

[0099] Preferably, the ammonium sulfate productization system 7 also includes a drying system, which includes a drying pipe 791, a cyclone separator 792, and a bag dust collector 793 connected in sequence, the conveying equipment 78 is connected to the drying pipe 791, the bag dust collector 793 is connected to the induced draft fan 794, the air inlet of the drying pipe 791 is connected to the air heater 795, and the air heater 795 is connected to the blower 796. The ammonium sulfate crystals are dried by the drying system, the heat source is hot air, the temperature is 150 degrees, and the temperature after drying is about 60 degrees.

[0100] In the present invention, valves, detection sensors and other components can be installed on each pipeline according to actual needs.

[0101] The present invention also provides a mud dehydration, drying and denitrification process, comprising the following steps:

[0102] Dehydration step: the material is fed into the dehydration, drying and denitrification integrated machine 1. After the material passes through the middle area of ​​the filter plate 11 and the filter press heating plate 12, it passes through the filter screen, and the filtrate flows out from the first liquid outlet 111 of the filter plate. After the material is dehydrated by the filter plate 11, a filter cake is formed in the middle chamber of the filter plate 11 and the filter press heating plate 12; as the filter cake is formed, when the feed pump reaches the preset pressure, the feed is stopped, the filter press pump 231 is turned on, and hot water is pumped from the filter press water tank 2 into the filter press heating plate 12, and the filter cake is squeezed by high-pressure hot water to further reduce the water content of the filter cake.

[0103] Drying step: After the dehydration step, the filter cake is in the middle chamber. At this time, the hot water pump 211 is turned on to pump hot water into the filter press heating plate 12 to heat the filter cake. The filtrate pipeline is evacuated by the vacuum system to vaporize the water in the filter cake and dry the filter cake.

[0104] Denitrification step: in the dehydration stage, the alkali adding device 32 adds filtrate to the dehydration, drying and denitrification integrated machine 1, and mixes it evenly with the effluent filtrate in the filter plate 11. Due to the increase in pH value and temperature, ammonia containing a portion of water escapes, is condensed by the condenser 31, and is sent to the first gas-liquid separation device 33. After adding alkali solution to adjust the pH value, the ammonia escapes to the nitrogen fixing system 4 again; in the drying stage, ammonia is extracted from the dehydration, drying and denitrification integrated machine 1, is condensed by the condenser 31, and is sent to the first gas-liquid separation device 33. After adding alkali solution to adjust the pH value, the ammonia escapes to the nitrogen fixing system 4 again.

[0105] In summary, the present invention effectively overcomes various shortcomings of the prior art and has high industrial utilization value.

[0106] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A sludge dehydration, drying and denitrification process, using sludge dehydration, drying and denitrification integrated equipment, characterized in that: The sludge dehydration, drying and denitrification integrated equipment comprises a dehydration, drying and denitrification integrated machine (1), a filter water pressure tank (2), a denitrification system (3), a nitrogen fixation system (4) and a feeding system (6). The dehydration, drying and denitrification integrated machine (1) comprises a plurality of filter plates (11) and filter press heating plates (12), wherein the filter plates (11) and the filter press heating plates (12) are arranged in a staggered manner, the filter plates (11) are provided with a first liquid outlet (111), and the filter press heating plates (12) are provided with a second liquid inlet (121) and a second liquid outlet (122); The filter press water tank (2) is provided with a heating water supply pipe (21), a heating water return pipe (22), a squeezing water supply pipe (23) and a squeezing water return pipe (24); the heating water supply pipe (21) and the squeezing water supply pipe (23) are respectively connected to the second liquid inlet (121); the heating water return pipe (22) and the squeezing water return pipe (24) are respectively connected to the second liquid outlet (122); The denitrification system (3) comprises a condenser (31), an alkali adding device (32) and a first gas-liquid separation device (33); the liquid inlet of the condenser (31) is connected to the total liquid outlet of the dehydration, drying and denitrification integrated machine (1) via a pipeline; the liquid outlet of the condenser (31) is connected to the first gas-liquid separation device (33) via a pipeline; the alkali adding device (32) is connected to the total liquid inlet of the dehydration, drying and denitrification integrated machine (1) via an alkali adding pipeline (321); an alkali adding branch pipe (322) is provided on the alkali adding pipeline (321); the alkali adding branch pipe (322) is in communication with the first gas-liquid separation device (33); The nitrogen fixation system (4) comprises a pickling device for reacting ammonia to generate ammonium sulfate mother liquor, the pickling device is connected to the first gas-liquid separation device (33), and the pickling device is connected to a vacuum pump (5); the pickling device comprises an acid adding device (41), a pickling tower (42) and a buffer tank (43), the acid adding device (41) is connected to the pickling tower (42), the first gas-liquid separation device (33) is connected to the pickling tower (42), the top outlet of the pickling tower (42) is connected to the buffer tank (43), the buffer tank (43) is connected to the vacuum pump (5), and the pickling tower (42) is also provided with a sulfur The ammonium sulfate productization system (7) comprises a mother liquid storage tank (71), a second gas-liquid separation device (72), a compressor (73), a preheater (74), a heater (75) and an evaporator (76), wherein the liquid outlet of the mother liquid storage tank (71) is connected to the liquid inlet of the preheater (74), the liquid outlet of the preheater (74) is connected to the liquid inlet of the heater (75), the liquid outlet of the heater (75) is connected to the liquid inlet of the evaporator (76); the steam outlet of the evaporator (76) is connected to the heater (75), and the evaporator (76) is connected to the steam outlet of the evaporator (76). A compressor (73) is also provided on a pipeline connecting the steam outlet of the preheater (76) and the heater (75); the water outlet of the preheater (75) is connected to the water inlet of the preheater (74); the water outlet of the preheater (74) is connected to the second gas-liquid separation device (72); the air inlet of the buffer tank (43) is connected to the second gas-liquid separation device (72); the ammonium sulfate productization system (7) also includes a cooling crystallization system and a drying system, the cooling crystallization equipment includes a cooling crystallization tank (771), a centrifuge (772) and a filtrate storage tank (773), and the liquid inlet of the cooling crystallization tank (771) The cooling crystallization tank (771) is connected to the liquid outlet of the evaporator (76), the centrifuge (772) is connected to the conveying device (78), and the conveying device (78) is connected to the drying system; and the air inlet of the buffer tank (43) is connected to the second gas-liquid separation device (72), so that the second gas-liquid separation device (72), the preheater (74), the heater (75), and the evaporator (76) are evacuated by the vacuum pump (5), and the vacuum pump (5) simultaneously provides a vacuum environment for the vacuum drying system, the denitrification system, and the ammonium sulfate productization system; The feeding system (6) comprises a sludge conditioning tank (61), the sludge conditioning tank (61) is connected to the feeding port of the dehydration, drying and denitrification integrated machine (1) through a feeding pipe (62), a feeding pump (63) and a return pipe (64) are provided on the feeding pipe (62), the return pipe (64) is connected to the sludge conditioning tank (61), and the return pipe (64) is connected in parallel with the feeding pump (63), and a part of the material in the feeding pipe (62) after the dehydration, drying and denitrification process is returned to the sludge conditioning tank (61) through the return pipe (64), and the sludge dehydration, drying and denitrification process comprises the following steps: a dehydration step: feeding the material into the dehydration, drying and denitrification integrated machine (1), and after the material is dehydrated by the filter plate (11), a filter cake is formed in the middle chamber (13) between the filter plate (11) and the filter press heating plate (12); Drying step: when the filter cake is in the middle chamber (13), the hot water pump (211) is turned on to pump hot water into the filter press heating plate (12) to heat the filter cake, so that water in the filter cake is vaporized and escapes; Denitrification step: in the dehydration stage, the alkali adding device (32) adds alkali solution to the filter plate (11), ammonia escapes, and is sent to the first gas-liquid separation device (33) after condensation by the condenser (31), and the alkali solution is added to adjust the pH value so that the ammonia escapes again to the nitrogen fixing system (4); in the drying stage, ammonia is extracted from the dehydration, drying and denitrification integrated machine (1), and is sent to the first gas-liquid separation device (33) after condensation by the condenser (31), and the alkali solution is added to adjust the pH value so that the ammonia escapes again to the nitrogen fixing system (4).

2. The sludge dehydration, drying and denitrification process according to claim 1, characterized in that: In the dehydration stage, when the feed pump reaches a preset pressure, the feed is stopped and the filter press pump (231) is turned on to pump high-pressure hot water into the filter press heating plate (12) to press the filter cake, thereby further reducing the moisture content of the filter cake.

3. The sludge dehydration, drying and denitrification process according to claim 1, characterized in that: The method also includes the following ammonium sulfate product production steps: the mother liquor enters the mother liquor storage tank (71) from the pickling tower for storage, enters the heater (75) after heat exchange in the preheater (74), and then enters the evaporator (76) for evaporation and concentration, and the concentrated liquid is discharged from the discharge liquid port of the evaporator (76) to the cooling crystallization system for crystallization; the secondary steam is discharged from the evaporator (76), and enters the heater (75) for heating after the compressor (73) increases the pressure and temperature, and then the condensed water flows by gravity to the preheater (74) for heating, and flows into the second gas-liquid separation device (72), and the condensed water is discharged from the second gas-liquid separation device (72).

4. The sludge dehydration, drying and denitrification process according to claim 1, characterized in that: The heating water supply pipe (21) is provided with a hot water pump (211), and the pressing water supply pipe (23) is provided with a filter press pump (231).

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