Phenol ammonia recovery pretreatment device

Abstract

The utility model belongs to the technical field of semi-coke wastewater treatment, and particularly relates to a phenol ammonia recovery pretreatment device which comprises a homogeneous sedimentation unit, an oil-water separation unit and a pre-extraction and recovery unit, heavy oil and light oil in the semi-coke wastewater are separated from the wastewater by the homogeneous settling unit through gravity settling, the treated semi-coke wastewater enters the oil-water separation unit for combined oil removal of multi-stage separation coalescence, and the oil-removed wastewater enters the pre-extraction and recovery unit for extraction and recovery; a homogeneous sedimentation unit, an oil-water separation unit and a pre-extraction and recovery unit are adopted; the stability and the treatment effect of the system are improved; according to the device, phenol, oil, ammonia and acid gas in the semi-coke wastewater are effectively removed through the oil-water separation unit and the pre-extraction and recovery unit, and the device is easy to operate, can effectively remove oil and dust entering the ammonia distillation tower, can effectively prolong the operation cycle of an ammonia distillation system, and is stable in operation.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of semi -coking wastewater treatment, specifically relates to a phenol ammonia recovery pretreatment device. BACKGROUND

[0002] Semi -coking wastewater is the wastewater generated in the process of coal in low temperature dry distillation (about 550 ~ 650 DEG C), contains phenol, tar and ammonia and other refractory organic pollutants, and the treatment difficulty is high, and the environmental hazards are big.

[0003] For semi -coking wastewater, the conventional treatment method usually includes: pretreatment, phenol ammonia recovery pretreatment and biochemical treatment three stages, wherein the phenol ammonia recovery pretreatment unit not only acts as the security system of the subsequent biochemical treatment system, is directly related to the good and bad of the operation of the biochemical treatment system, is also related to the recovery of valuable resources in semi -coking wastewater, and therefore the phenol ammonia recovery pretreatment unit is the key to the success of semi -coking wastewater treatment.

[0004] Although the traditional phenol ammonia recovery treatment can effectively treat and recover phenol, ammonia pollutants in semi -coking wastewater, due to the limitation on the device, the traditional phenol ammonia recovery treatment has the problems of poor system operation stability, and the specific manifestations are as follows:

[0005] 1, the traditional phenol ammonia recovery pretreatment, wastewater is often directly into the subsequent deacidification ammonia tower after oil removal by gravity or air floatation, due to the special water quality of semi -coking wastewater, only through gravity or air floatation can often not solve the suspended pollutants such as coke powder, coal powder, tar colloid in wastewater, so that these pollutants enter the subsequent tower, which can easily cause the blockage of tower plate, heat exchanger and pipeline, and affect the system stability.

[0006] 2, for the phenol ammonia recovery treatment of semi -coking wastewater, in the traditional treatment, a cooler is generally arranged before the extraction tower, due to the generation of polymerization oil pollution after the heating of the deacidification ammonia tower, the oil is precipitated from the system after heat exchange cooling, and large oil pollution is generated, which causes the cooling device to be blocked frequently, the heat exchange efficiency is reduced, the extraction inlet water temperature is high and other problems.

[0007] 3, the extraction system usually only uses an extraction tower as the core equipment, the deacidification effluent fluctuates greatly, and the extraction working condition is unstable, so that the effluent COD and other indicators are unqualified. UTILITY MODEL CONTENTS

[0008] The utility model aims at providing a phenol ammonia recovery pretreatment device to solve the technical problem of poor system operation stability in the prior art phenol ammonia recovery treatment.

[0009] In order to achieve the above-mentioned purpose, the utility model adopts the following technical scheme:

[0010] A phenol ammonia recovery pretreatment device, comprising a homogeneous settling unit, an oil-water separation unit and a pre-extraction and recovery unit; the homogeneous settling unit separates heavy oil, light oil and wastewater in the semi-coke wastewater by gravity settling, and the treated semi-coke wastewater enters the oil-water separation unit for multi-stage separation and coalescence combined oil removal, and the oil-removed wastewater enters the pre-extraction and recovery unit for extraction and recovery.

[0011] Preferably, the homogeneous settling unit is a raw water tank, which uniformly mixes the semi-coke wastewater produced in the previous process and then removes oil by gravity, separates heavy oil, light oil and wastewater in the semi-coke wastewater by gravity settling and standing, and discharges heavy oil at the bottom of the semi-coke wastewater storage tank, light oil at the upper part, and oil-removed semi-coke wastewater at the middle part into the oil-water separation unit.

[0012] Preferably, the oil-water separation unit comprises a primary oil-water separation device and a secondary oil-water separation device, the primary oil-water separation device and the secondary oil-water separation device are connected, the primary oil-water separation device is connected with the homogeneous settling unit, and the secondary oil-water separation device is connected with the pre-extraction and recovery unit.

[0013] Preferably, the primary oil-water separation device comprises a first chamber, a second chamber and a third chamber; the first chamber, the second chamber and the third chamber are sequentially communicated, and saddles are respectively installed at the bottoms of the first chamber and the third chamber; a water inlet is arranged on the first chamber, and a device water outlet is arranged on the third chamber; first and second backwash water inlets are respectively arranged on the first chamber and the third chamber; first and second light oil discharge outlets are respectively arranged on the first chamber and the second chamber.

[0014] Preferably, the water inlet on the first chamber is inwardly connected with a water distribution pipe, and a first chamber oil removal element is arranged on the water distribution pipe; the first chamber oil removal element separates out light oil into a first light oil collection bag above the first chamber oil removal element, and separates out heavy oil into a first chamber heavy oil collection bag below the first chamber oil removal element.

[0015] The second chamber is provided with a second oil removal element, the second oil removal element is in contact with the first oil removal element of the first chamber, the water outlet of the first chamber is connected with a water distribution pipe of the second chamber, the water distribution pipe of the second chamber uniformly distributes wastewater on the second oil removal element, the water outlet is uniformly distributed on the first oil removal element of the third chamber by a connecting pipe and a water distribution pipe of the third chamber, separated light oil is discharged into a second light oil collection bag, separated heavy oil is discharged into a second heavy oil collection bag, and the water outlet is connected with the secondary oil-water separation device through the device water outlet.

[0016] Preferably, the secondary oil-water separation device comprises a first chamber, a second chamber and a third chamber; the first chamber, the second chamber and the third chamber are sequentially communicated, the first chamber and the second chamber are connected with the primary oil-water separation device, the bottom of the first chamber and the third chamber is respectively provided with a device saddle, the first chamber, the second chamber and the third chamber are respectively provided with a first chamber water inlet, a second chamber water inlet and a third chamber water inlet, and the first chamber, the second chamber and the third chamber are respectively provided with a first chamber backwashing water inlet, a second chamber backwashing water inlet and a third chamber backwashing water inlet; the bottom of the first chamber, the second chamber and the third chamber is respectively provided with a first chamber blowdown, a second chamber blowdown and a third chamber blowdown; the top of the third chamber is further provided with a device light oil collection bag and a water outlet, and the bottom of the third chamber is further provided with a device heavy oil collection bag.

[0017] Preferably, the water outlet of the primary oil-water separation device enters the secondary oil-water separation device through the first chamber water inlet and the second chamber water inlet, the first chamber water inlet and the second chamber water inlet are both connected with a water distribution pipe, the lower part of the water distribution pipe is provided with a third oil removal element, the third oil removal element is connected with a first chamber water outlet and a second chamber water outlet, the first chamber water outlet and the second chamber water outlet are connected with the third chamber water inlet through a pipe, the third chamber water inlet is connected with a third chamber water distribution pipe, the third chamber water distribution pipe is provided with a first oil removal element, and the water after the oil removal of the first oil removal element is discharged from the equipment through a water outlet.

[0018] Preferably, the pre-extraction and recovery unit comprises a pipeline extractor, the pipeline extractor is connected with a separation tank, the separation tank is connected with an extract tank and a solvent recovery column, the solvent recovery column is provided with a solvent recovery column liquid separator, a solvent recovery column overhead condenser and a solvent recovery column feed and discharge heat exchanger, and the solvent recovery column is connected with a washing tower, water outlet of the separation tank enters the solvent recovery column, is heated by the solvent recovery column feed and discharge heat exchanger and then returns to the solvent recovery column, gas phase of the solvent recovery column top is cooled by the solvent recovery column overhead condenser and then enters the solvent recovery column liquid separator, water phase at the bottom of the solvent recovery column liquid separator returns to the top of the column, oil phase at the lower part of the tank enters a solvent circulation tank, and gas phase at the top of the tank enters the lower part of the washing tower and is output after being washed by purified water.

[0019] Preferably, the first oil removal element of the first chamber and the first oil removal element of the third chamber are coalescence oil removal materials with super oil-wetting and water-repellent properties, and the second oil removal element is a space fiber mesh structure.

[0020] Preferably, the third oil removal element is a modified high-molecular organic composite membrane material, and the first oil removal element is a coalescence oil removal material with super oil-wetting and water-repellent properties.

[0021] Compared with the prior art, the oil-water separation device has the following beneficial effects:

[0022] The utility model discloses a kind of new phenol ammonia recovery pretreatment devices, including first-stage oil-water separation equipment, second-stage oil-water separation equipment, homogeneous sedimentation unit, oil-water separation unit and pre-extraction and recovery unit, the phenol ammonia recovery pretreatment device is used to solve the problems of traditional phenol ammonia recovery treatment in semi-coke wastewater, by optimizing and integrating treatment process, using homogeneous sedimentation unit, oil-water separation unit and pre-extraction and recovery unit;The stability and treatment effect of system are improved;Phenol, oil, ammonia and acid gas in semi-coke wastewater are effectively removed by oil-water separation unit and pre-extraction and recovery unit, the device has easy operation, can effectively remove oil and dust into ammonia distillation tower, can effectively prolong the running cycle of ammonia distillation system, and the device runs stably.The application of the new phenol ammonia recovery pretreatment device effectively reduces the oil and dust into phenol ammonia recovery system, reduces the operation cost of phenol ammonia recovery system, reduces the time of tower and heat exchanger blockage of phenol ammonia recovery system, and improves the running cycle. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical scheme of the embodiments of the utility model, the following will be briefly introduced to the drawings needed to be used in the embodiments, it should be understood that the following drawings only show some embodiments of the utility model, therefore should not be regarded as the limitation to the scope, for ordinary skilled person in the art, under the premise of not paying the creative labor, can also obtain other related drawings according to these drawings.

[0024] Figure 1 It is the oil-water separation process flow chart of the utility model;

[0025] Figure 2 It is the pre-extraction and recovery process flow chart of the utility model;

[0026] Figure 3 It is the first-stage oil-water separation equipment structure schematic view of the utility model;

[0027] Figure 4 It is the second-stage oil-water separation equipment structure schematic view of the utility model.

[0028] Among them: 1-first-stage oil-water separation equipment;102-water inlet;103-first backwash water inlet;104-water distribution pipe;105-first light oil collection bag;106-first light oil pay oil outlet;107-second light oil pay oil outlet;108-connection pipe;109-second oil removal element;110-second backwash water inlet;111-second light oil collection bag;112-three-chamber first oil removal element;113-equipment water outlet;114-one-chamber first oil removal element;115-first blowdown;116-saddle;117-first heavy oil collection bag;118-second blowdown;119-second heavy oil collection bag;120-third blowdown;

[0029] 2 - secondary oil-water separation device; 201 - one-chamber water inlet distribution port; 202 - one-chamber backwash water inlet; 203 - third oil removal element; 204 - one-chamber water outlet; 205 - two-chamber water outlet; 206 - two-chamber backwash water inlet; 207 - two-chamber water inlet distribution port; 208 - three-chamber water inlet distribution port; 209 - device light oil collection bag; 210 - three-chamber backwash water inlet; 211 - first oil removal element; 212 - three-chamber water distribution pipe; 213 - water outlet; 214 - steam inlet pipe; 215 - one-chamber blowdown port; 216 - two-chamber blowdown port; 217 - device heavy oil collection bag; 218 - device saddle; 219 - three-chamber blowdown port;

[0030] 3 - pipe extractor; 4 - separation tank; 5 - solvent recovery column; 6 - solvent recovery column separation tank; 7 - washing column; 8 - solvent recovery column overhead condenser; 9 - solvent recovery column feed / effluent heat exchanger. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative labor are within the scope of protection of the present application.

[0033] It should be noted that: similar reference numbers and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0034] In the description of the embodiments of the present application, it should be noted that if the terms "upper", "lower", "horizontal", "inner" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship when the product of the present application is used, which is only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second" and the like are only used for differentiation in description, and cannot be understood as indicating or implying relative importance.

[0035] Furthermore, if the term "horizontal" is used, it is not meant to require absolutely horizontal surfaces, but rather can be slightly inclined. As such, the term "horizontal" is used herein to merely mean more horizontal than vertical, and thus can include slight inclinations.

[0036] In the description of the embodiments of the present application, it should also be noted that unless specifically defined and limited, if the terms "set", "install", "connect", "connect" appear, they should be understood in a broad sense, for example, they can be fixedly connected, or can be detachably connected, or integrally connected, can be mechanically connected, or can be electrically connected, can be directly connected, or indirectly connected through an intermediate medium, or can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0037] The present application will be described in further detail below with reference to the accompanying drawings:

[0038] Referring to Figures 1-4 The phenol ammonia recovery pretreatment device disclosed in the present application is characterized by comprising a homogenizing and settling unit, an oil-water separation unit and a pre-extraction and recovery unit. The heavy oil and light oil in the semi-coke wastewater are separated from the wastewater by gravity settling through the homogenizing and settling unit, and the treated semi-coke wastewater enters the oil-water separation unit for multi-stage separation and coalescence combined oil removal. The oil-removed wastewater enters the pre-extraction and recovery unit for extraction and recovery. The homogenizing and settling unit, the oil-water separation unit and the pre-extraction and recovery unit are adopted, thereby improving the stability and treatment effect of the system. The phenol, oil, ammonia and acidic gas in the semi-coke wastewater are effectively removed through the oil-water separation unit and the pre-extraction and recovery unit. The device has the advantages of easy operation, effective removal of oil and dust entering the ammonia stripping tower, effective extension of the operation cycle of the ammonia recovery system, and stable operation of the device. Through the application of the novel phenol ammonia recovery pretreatment device, the oil and dust entering the phenol ammonia recovery system are effectively reduced, the operation cost of the phenol ammonia recovery system is reduced, the time for plugging the tower and heat exchanger of the phenol ammonia recovery system is reduced, and the operation cycle is improved.

[0039] In some embodiments, the homogenizing and settling unit is a raw water tank. The raw water tank separates the heavy oil and light oil in the semi-coke wastewater produced in the previous process from the wastewater by gravity oil removal after mixing the semi-coke wastewater uniformly. The heavy oil, light oil and wastewater in the semi-coke wastewater are separated by gravity settling and standing. After standing, the heavy oil is discharged at the bottom of the semi-coke wastewater storage tank, the light oil is discharged at the upper part, and the oil-removed semi-coke wastewater is discharged at the middle part and enters the oil-water separation unit. The raw water tank is used to separate the heavy oil and light oil in the semi-coke wastewater produced in the previous process from the wastewater by gravity oil removal after mixing the semi-coke wastewater uniformly. The semi-coke wastewater is settled and stood for 36-72h in the storage tank by gravity settling, so as to separate the heavy oil and light oil in the semi-coke wastewater from the wastewater.

[0040] In some embodiments, referring to Figure 1 , the oil-water separation unit comprises: a first oil-water separation device 1 and a second oil-water separation device 2, the first oil-water separation device 1 and the second oil-water separation device 2 are connected, and the first oil-water separation device 1 is connected with the homogeneous sedimentation unit, and the second oil-water separation device 2 is connected with the pre-extraction and recovery unit.

[0041] Specifically, referring to Figure 3 , the first oil-water separation device 1 comprises: a first chamber, a second chamber and a third chamber; the first chamber, the second chamber and the third chamber are sequentially communicated, and the bottoms of the first chamber and the third chamber are respectively provided with saddles 116; the first chamber is provided with a water inlet 102, and the third chamber is provided with a device water outlet 113; the first chamber and the third chamber are respectively provided with a first backwash water inlet 103 and a second backwash water inlet 110; the first chamber and the second chamber are respectively provided with a first light oil discharge outlet 106 and a second light oil discharge outlet 107.

[0042] Further preferably, the water inlet 102 on the first chamber is inwardly connected with a water distribution pipe 104, the water distribution pipe 104 is provided with a first chamber oil removal element 114, the first chamber oil removal element 114 separates out light oil into a first light oil collection bag 105 above the first chamber oil removal element 114, and the first chamber oil removal element 114 separates out heavy oil into a first chamber heavy oil collection bag 117 below the first chamber oil removal element 114;

[0043] The second chamber is provided with a second oil removal element 109, the second oil removal element 109 is in contact with the first chamber oil removal element 114, the water outlet of the first chamber is connected with a water distribution pipe of the second chamber, the water distribution pipe of the second chamber uniformly distributes wastewater on the second oil removal element 109, the water outlet is uniformly distributed on a first oil removal element 112 of the third chamber by a connecting pipe 108, the separated light oil is discharged into a second light oil collection bag 111, the separated heavy oil is discharged into a second heavy oil collection bag 119, and the water outlet is connected with the second oil-water separation device 2 through the device water outlet 113.

[0044] The water inlet 102 of the first oil-water separation device 1 is connected with the water distribution pipe 104, the water distribution pipe 104 is connected with the first chamber oil removal element 114, the first chamber oil removal element 114 is connected with the second oil removal element 109, the second oil removal element 109 is connected with the first oil removal element 112 of the third chamber, and the first oil removal element 112 of the third chamber is connected with the device water outlet 113.

[0045] In some embodiments, referring to Figure 4The secondary oil-water separation device 2 comprises a first chamber, a second chamber and a third chamber; the first chamber, the second chamber and the third chamber are sequentially communicated, the first chamber and the second chamber are connected with the primary oil-water separation device 1, the first chamber and the third chamber are provided with device saddles 218 at the bottom, the first chamber, the second chamber and the third chamber are respectively provided with a first chamber water inlet 201, a second chamber water inlet 207 and a third chamber water inlet 208, and the first chamber, the second chamber and the third chamber are respectively provided with a first chamber backwash water inlet 202, a second chamber backwash water inlet 206 and a third chamber backwash water inlet 210; the first chamber, the second chamber and the third chamber are respectively provided with a first chamber blowdown 215, a second chamber blowdown 216 and a third chamber blowdown 219; the third chamber is further provided with a device light oil collection package 209 and a water outlet 213 at the top, and is further provided with a device heavy oil collection package 217 at the bottom. The water outlet of the primary oil-water separation device 1 enters the secondary oil-water separation device 2 through the first chamber water inlet 201 and the second chamber water inlet 207, the first chamber water inlet 201 and the second chamber water inlet 207 are connected with the water distribution pipe inward, the water distribution pipe is provided with a third oil removal element 203 below, the third oil removal element 203 is connected with a first chamber water outlet 204 and a second chamber water outlet 205, the first chamber water outlet 204 and the second chamber water outlet 205 are connected with the third chamber water inlet 208 through the pipe, the third chamber water inlet 208 is connected with a third chamber water distribution pipe 212 inward, the third chamber water distribution pipe 212 is provided with a first oil removal element 211, and the water after the first oil removal element 211 is removed is discharged from the water outlet 213.

[0046] The water outlet of the primary oil-water separation device 1 enters the secondary oil-water separation device 2 through the first chamber water inlet 201 and the second chamber water inlet 207, the first chamber water inlet 201 and the second chamber water inlet 207 are connected with the water distribution pipe, the water distribution pipe is connected with the third oil removal element 203, the third oil removal element 203 is connected with the first chamber water outlet 204 and the second chamber water outlet 205, the first chamber water outlet 204 and the second chamber water outlet 205 are connected with the third chamber water inlet 208 through the pipe, the third chamber water inlet 208 is connected with the third chamber water distribution pipe 212, the third chamber water distribution pipe 212 is connected with the first oil removal element 211, and the first oil removal element 211 is connected with the water outlet 213.

[0047] Referring to Figure 2The pre-extraction and recovery unit comprises a pipeline extractor 3, a separation tank 4 connected with the pipeline extractor 3, an extract tank and a solvent recovery column 5 connected with the separation tank 4, a solvent recovery column liquid separator 6, a solvent recovery column overhead condenser 8 and a solvent recovery column feed and discharge heat exchanger 9 arranged on the solvent recovery column 5, and a washing column 7 connected with the solvent recovery column 5. The water from the separation tank 4 enters the solvent recovery column 5, is heated by the solvent recovery column feed and discharge heat exchanger 9 and then returns to the solvent recovery column 5. The gas phase at the top of the solvent recovery column 5 is cooled by the solvent recovery column overhead condenser 8 and then enters the solvent recovery column liquid separator 6. The water phase at the bottom of the solvent recovery column liquid separator 6 returns to the top of the column, and the oil phase at the lower part of the column enters a solvent circulation tank. The gas phase at the top of the column enters the lower part of the washing column 7 and is output after being washed by purified water.

[0048] In some embodiments, the materials in the primary oil-water separation device 1 and the secondary oil-water separation device 2 have strong lipophilicity and strong demulsification function. The primary oil-water separation device 1 and the secondary oil-water separation device 2 adopt a combined oil removal process of multi-stage separation and coalescence. The first oil removal element 114 in the first-stage chamber, the first oil removal element 112 in the third-stage chamber and the first oil removal element 211 adopt coalescence oil removal materials with super-lipophilicity and super-hydrophobicity to strengthen the efficiency of collision coalescence. The principle is wetting coalescence and collision coalescence. The second oil removal element 109 adopts a space fiber mesh structure composed of lipophilic and hydrophobic modified materials, which has strong wettability and is beneficial to the coalescence of oil droplets. The third oil removal element 203 is a modified high-molecular organic composite membrane material. The composite membrane is formed by organically combining a super-hydrophilic modified composite fiber membrane and a super-hydrophobic modified composite fiber membrane, forming an asymmetric super-wetting composite fiber membrane with a multi-level structure and high porosity, a large specific surface area, and being not easy to be polluted by oil stains. The modified high-molecular organic composite membrane material can effectively treat the emulsified oil in the semi-coke wastewater, recover part of the coal tar and produce economic benefits. The materials at different levels are arranged in the two-stage device through multi-stage arrangement and combination, and the special structure design for effectively improving the residence time and reducing the resistance is adopted, so as to form an oil removal unit of the semi-coke wastewater.

[0049] Referring to Figure 2 The pre-extraction and recovery unit: the water from the oil-water separation unit enters the pipeline extractor 3, is mixed with the extract at the top of the extraction tower in the phenol-ammonia recovery unit (or fresh extractant can be directly used) for mixed extraction (extraction ratio 1.5:10), is uniformly mixed and then enters the separation tank 4 to separate the extract and the pre-extracted water. The separated extract returns to the extract tank, and the separated sewage enters the solvent recovery column 5.

[0050] The separation tank 4 is a static separator, the water phase (containing phenolic wastewater) from the static separator enters the solvent recovery column 5, exchanges heat with the solvent recovery column kettle water through the feed and discharge heat exchanger 9 to 105℃, and enters the solvent recovery column 5. The gas phase at the top of the solvent recovery column enters the solvent recovery column liquid-liquid separator tank 6 after being condensed and cooled by the solvent recovery column overhead condenser 8. The water phase at the bottom of the solvent recovery column liquid-liquid separator tank 6 is used as the reflux of the solvent recovery column 5, is pressurized by the reflux pump and then returns to the top of the column. The oil phase at the lower part of the tank enters the solvent circulating tank, and the gas phase at the top of the tank enters the lower part of the washing tower 7 and is washed by the purified water, and then the gas phase (mainly acidic gas) is discharged from the device. The liquid phase at the bottom of the washing tower is pressurized and returned to the deacidification and desolventization column feed pipeline. The heat source of the solvent recovery column kettle is 0.72Mpa low-pressure steam.

[0051] The liquid phase from the solvent recovery column kettle is exchanged heat by the first partial condenser and the phenol water heat exchanger to 125℃ as the hot feed of the deacidification tower, and enters the deacidification tower. The bottom of the deacidification tower uses the deacidification tower reboiler to provide the heat required for stripping, and the bottom temperature is controlled at about 160℃. The gas phase at the top of the column is acidic gas, which is sent to the scrubber and countercurrently contacted with the spray water entering the top of the scrubber, further absorbing the solvent in the acidic gas, and the acidic gas is sent out of the scrubber from the top. The upper layer of the liquid phase is solvent, which overflows into the solvent overflow tank and then enters the solvent circulating tank. The lower layer of the water phase is used as the reflux of the deacidification tower and is sent to the deacidification tower by the deacidification tower top reflux pump. The purified water at the bottom of the deacidification tower is pressurized by the deacidification tower kettle phenol water pump and sent to the deamination tower.

[0052] Example 1:

[0053] The wastewater to be treated is the wastewater of a certain coking plant, which has not been treated by deacidification and ammonia stripping, and the main indicators are as follows: COD: 40000mg / L; oil: 2000mg / L; total phenol: 12000mg / L; NH3-N: 6000mg / L; pH value: 11.

[0054] The system includes a raw water tank, a first oil-water separation device 1, a second oil-water separation device 2, a tar storage tank, an intermediate water tank, a pipeline extractor 3, a separation tank 4, a desolventization tower, a washing tower 7 and a series of devices. The wastewater from the coking plant is connected to the upper part of the first oil-water separation device 1, the middle part of the first oil-water separation device 1 is connected to the middle part of the second oil-water separation device 2, the middle part of the first oil-water separation device 1 is connected to the upper part of the second oil-water separation device 2 and the bottom part is connected to the upper part of the tar storage tank, and the middle part of the new second oil-water separation device is connected to the middle part of the intermediate water tank.

[0055] The water from the secondary oil-water separation device 2 is mixed with the extractant from the top of the extraction column of the phenol-ammonia recovery unit (or fresh extractant) by a pipe mixer, and then mixed extraction is carried out (extraction ratio 1.5:10). After uniform mixing, the mixture is introduced into a static separator to separate the extractant and the water after pre-extraction. The separated extractant is returned to the extractant tank, and the separated sewage is introduced into the deacidification and desolventization column.

[0056] The water phase (containing phenol wastewater) from the static separator is introduced into the deacidification and desolventization column, and is heated to 105°C by a feed heat exchanger to enter the solvent recovery column. The gas phase from the top of the column is condensed and cooled, and then introduced into a liquid separator tank of the deacidification and desolventization column. The water phase at the bottom of the tank is used as reflux of the solvent recovery column, and is pressurized by a reflux pump to return to the top of the column. The oil phase at the upper part of the tank is introduced into a solvent circulation tank, and the gas phase from the top of the tank is introduced into the lower part of a washing column, and then is washed by purified water to be discharged from the device (the gas phase mainly contains acidic gas). The liquid phase from the bottom of the washing column is pressurized to return to the feed pipeline of the deacidification and desolventization column.

[0057] The heat source of the solvent recovery column is 0.72 MPa low-pressure steam.

[0058] The liquid phase from the bottom of the solvent recovery column is heated to 125°C by a primary condenser and a phenol water heat exchanger to be used as hot feed of the deacidification column. The deacidification column is heated by a deacidification column reboiler to provide heat required for stripping, and the temperature at the bottom of the column is controlled to be about 160°C. The gas phase from the top of the column is acidic gas, and is sent to a scrubber to be contacted with spraying water at the top of the scrubber to further absorb solvent in the acidic gas. The solvent in the upper layer of the liquid phase overflows into a solvent overflow tank, and then is introduced into a solvent circulation tank. The water phase in the lower layer is used as reflux of the deacidification column, and is sent to the deacidification column by a deacidification column reflux pump.

[0059] The actual treatment process of the wastewater is as follows: the coking waste water is statically placed in the raw water tank for 36 hours, and then is pumped into the middle of the first oil-water separation device 1 and the second oil-water separation device 2. The removed part of the coal tar is sent to a tar storage tank.

[0060] The water from the second oil-water separation device 2 is mixed with the extractant from the top of the extraction column of the phenol-ammonia recovery unit (or fresh extractant) by a pipe mixer, and then mixed extraction is carried out (extraction ratio 1.5:10). After uniform mixing, the mixture is introduced into a static separator to separate the extractant and the water after pre-extraction. The separated extractant is returned to the extractant tank, and the separated sewage is introduced into the deacidification and desolventization column.

[0061] The water phase (containing phenol wastewater) from the static separator enters the deacidification and desolventizing column, is heated to 105 DEG C by the feed heat exchanger and the solvent recovery column bottom water, and enters the solvent recovery column. The gas phase at the top of the column enters the deacidification and desolventizing column after being condensed and cooled, the water phase at the bottom of the tank is used as the reflux of the solvent recovery column, is pressurized by a reflux pump, and returns to the top of the column, the oil phase at the lower part of the tank enters the phenol column, and the gas phase at the top of the tank enters the lower part of the washing column and is washed by purified water, and the gas phase is discharged from the device (the gas phase is mainly acidic gas), and the liquid phase at the bottom of the washing column is pressurized and returned to the feed pipeline of the deacidification and desolventizing column.

[0062] The heat source of the solvent recovery column bottom is 0.72Mpa low-pressure steam.

[0063] The liquid phase from the solvent recovery column bottom is heated to 125 DEG C by a primary condenser and a phenol water heat exchanger, and is used as the hot feed of the deacidification column. The bottom of the deacidification column uses the deacidification column reboiler to provide the heat required for stripping, and the bottom temperature is controlled at about 160 DEG C. The gas phase at the top of the column is acidic gas, is sent to the scrubber, and is countercurrently contacted with the spray water entering the top of the scrubber, further absorbs the solvent in the acidic gas, and the acidic gas is sent out of the scrubber from the top; the upper layer of the liquid phase is solvent, overflows into the solvent overflow tank, and then enters the solvent circulating tank; and the lower layer of the water phase is used as the top reflux of the deacidification column and is sent to the deacidification column by a deacidification column top reflux pump for reflux. The purified water at the bottom of the deacidification column is pressurized by a deacidification column bottom phenol water pump and is sent to the deamination column.

[0064] Through the treatment of the whole device system, the wastewater ammonia stripping and phenol removal treatment water indexes are as follows: COD: 5000mg / L, oil: 50mg / L; total phenol: 600mg / L; NH3-N: 300mg / L; pH value: 6~9; the removal rate of COD is 80%, the removal rate of oil is 90%, the removal efficiency of phenols is 95%, and the removal efficiency of NH3-N is greater than 92.5%.

[0065] The above is only a preferred embodiment of the utility model, and is not used for limiting the utility model. For those skilled in the art, the utility model can have various changes and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the utility model should be included in the protection scope of the utility model.

Claims

1. A phenol and ammonia recovery pretreatment device, characterized in that, It includes a homogenization sedimentation unit, an oil-water separation unit, and a pre-extraction and recovery unit. The homogenization sedimentation unit separates heavy oil and light oil from the wastewater in the semi-coke wastewater through gravity sedimentation. The treated semi-coke wastewater enters the oil-water separation unit for multi-stage separation and coalescence combined oil removal. The oil-removed wastewater enters the pre-extraction and recovery unit for extraction and recovery.

2. The phenol and ammonia recovery pretreatment device according to claim 1, characterized in that, The homogenization settling unit is a raw material water tank. The raw material water tank mixes the semi-coke wastewater produced in the previous process evenly and then removes oil by gravity. Through gravity settling and settling, the heavy oil and light oil in the semi-coke wastewater are separated from the wastewater. After settling, the heavy oil is discharged from the bottom of the semi-coke wastewater storage tank, the light oil is discharged from the top, and the oil-removed semi-coke wastewater is discharged from the middle and enters the oil-water separation unit.

3. The phenol and ammonia recovery pretreatment device according to claim 1, characterized in that, The oil-water separation unit includes a primary oil-water separation device (1) and a secondary oil-water separation device (2), which are connected to each other. The primary oil-water separation device (1) is connected to the homogenization sedimentation unit, and the secondary oil-water separation device (2) is connected to the pre-extraction and recovery unit.

4. The phenol and ammonia recovery pretreatment device according to claim 3, characterized in that, The primary oil-water separation device (1) includes: a first-stage chamber, a second-stage chamber, and a third-stage chamber; the first-stage chamber, the second-stage chamber, and the third-stage chamber are connected in sequence, and saddles (116) are installed at the bottom of the first-stage chamber and the third-stage chamber, respectively; an inlet (102) is provided on the first-stage chamber, and an outlet (113) is provided on the third-stage chamber; a first backwash water inlet (103) and a second backwash water inlet (110) are provided on the first-stage chamber and the third-stage chamber, respectively; a first light oil by-product discharge outlet (106) and a second light oil by-product discharge outlet (107) are provided on the first-stage chamber and the second-stage chamber, respectively.

5. The phenol and ammonia recovery pretreatment device according to claim 4, characterized in that, The inlet (102) on the first chamber is connected to a water distribution pipe (104). The water distribution pipe (104) is equipped with a first oil removal element (114) for the first chamber. The first oil removal element (114) separates light oil and discharges it into a light oil collection bag (105) above it. The first oil removal element (114) separates heavy oil and discharges it into a heavy oil collection bag (117) below it. The second oil removal element (109) is installed in the second chamber. The second oil removal element (109) is in contact with the first oil removal element (114) in the first chamber. The water outlet of the first chamber is connected to the water distribution pipe of the second chamber. The water distribution pipe of the second chamber distributes the wastewater evenly on the second oil removal element (109). The water outlet is evenly distributed on the first oil removal element (112) of the third chamber through the connecting pipe (108). The separated light oil is discharged into the second light oil collection bag (111). The separated heavy oil enters the second heavy oil collection bag (119). The water outlet is connected to the secondary oil-water separation equipment (2) through the equipment outlet (113).

6. The phenol and ammonia recovery pretreatment device according to claim 3, characterized in that, The secondary oil-water separation device (2) includes: a first chamber, a second chamber, and a third chamber; the first chamber, the second chamber, and the third chamber are connected in sequence, the first chamber and the second chamber are connected to the primary oil-water separation device (1), and the bottom of the first chamber and the third chamber are provided with equipment saddles (218), and the first chamber, the second chamber, and the third chamber are respectively provided with a water inlet (201), a water inlet (207), and a water inlet (208) for the third chamber, and the first chamber, the second chamber, and the third chamber are respectively provided with water inlets (201, 207, and 208). The first chamber and the third chamber are respectively provided with a backwash water inlet (202), a backwash water inlet (206), and a backwash water inlet (210); the bottom of the first chamber, the second chamber, and the third chamber are respectively provided with a drain outlet (215), a drain outlet (216), and a drain outlet (219); the top of the third chamber is also provided with a light oil collection bag (209) and a water outlet (213), and the bottom is also provided with a heavy oil collection bag (217).

7. The phenol and ammonia recovery pretreatment device according to claim 6, characterized in that, The effluent from the primary oil-water separator (1) enters the secondary oil-water separator (2) through the inlet water distribution port (201) of the first chamber and the inlet water distribution port (207) of the second chamber. Both the inlet water distribution port (201) and the inlet water distribution port (207) of the first chamber are connected to the water distribution pipe. A third oil removal element (203) is installed below the water distribution pipe. The third oil removal element (203) is connected to the outlet water outlet (204) of the first chamber. The outlet of the second chamber (205), the outlet of the first chamber (204) and the outlet of the second chamber (205) are connected to the inlet and distribution port of the third chamber (208) through piping. The inlet and distribution port of the third chamber (208) is connected to the distribution pipe of the third chamber (212) inward. The first oil removal element (211) is installed on the distribution pipe of the third chamber (212). After the first oil removal element (211) removes oil, the water is discharged from the equipment through the outlet (213).

8. The phenol and ammonia recovery pretreatment device according to claim 1, characterized in that, The pre-extraction and recovery unit includes a pipeline extractor (3), which is connected to a separation tank (4). The separation tank (4) is connected to the extract tank and the solvent recovery tower (5). The solvent recovery tower (5) is equipped with a solvent recovery tower separator (6), a solvent recovery tower top condenser (8), and a solvent recovery tower inlet and outlet heat exchanger (9). The solvent recovery tower (5) is also connected to a washing tower (7). Water from the separation tank (4) enters the solvent recovery tower (5), and after being heated by the solvent recovery tower inlet and outlet heat exchanger (9), it returns to the solvent recovery tower (5). The gas phase at the top of the solvent recovery tower is cooled by the solvent recovery tower top condenser (8) and then enters the solvent recovery tower separator (6). The water phase at the bottom of the separator (6) flows back to the top of the tower, the oil phase at the bottom of the tank enters the solvent circulation tank, and the gas phase at the top of the tank enters the bottom of the washing tower (7). After being washed with purified water, the gas phase is output.

9. A phenol and ammonia recovery pretreatment device according to claim 5, characterized in that, The first oil removal element (114) of the first chamber and the first oil removal element (112) of the third chamber are coalescing oil removal materials with super oleophilic and hydrophobic properties, and the second oil removal element (109) is a spatial fiber mesh structure.

10. A phenol and ammonia recovery pretreatment device according to claim 7, characterized in that, The third oil removal element (203) is a modified polymer organic composite membrane material, and the first oil removal element (211) is a coalescing oil removal material with super oleophilic and hydrophobic properties.

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