Coking sewage treatment device

Abstract

The utility model discloses a coking sewage treatment device. Coke generated in a coking device is utilized to realize the functions of sewage oil removal and coke powder removal. The coking sewage treatment device comprises an oil-containing sewage treatment tank, the top of the oil-containing sewage treatment tank is provided with a tank top inlet, the bottom of the oil-containing sewage treatment tank is provided with a tank bottom outlet, the side face of the oil-containing sewage treatment tank is provided with at least two tank side face flushing ports at different heights in the vertical direction, and the other side face opposite to the tank side face flushing ports is provided with at least four tank side face coke discharging ports at different heights in the vertical direction. A Johnson net is arranged at the bottom in the tank, a coke layer partition plate is arranged above the Johnson net, and one or more layers of one-way anti-mixing pore plates are arranged between a top seal head of the tank and the coke layer partition plate. According to the utility model, the sewage can be discharged up to the standard or conveyed to a downstream device and a sewage treatment plant.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the coking field, concretely relates to a coking sewage treatment device. BACKGROUND

[0002] The delayed coking process is an important residual oil processing process in petroleum processing flow. The raw material is heated to about 500 DEG C by heat exchange and coking furnace, and then enters the coke drum for thermal cracking reaction and condensation reaction, and oil gas and solid coke are generated in the coke drum. The oil gas generated by thermal cracking reaction enters the fractionating tower through the coke drum top oil gas line, and is separated into rich gas and naphtha, diesel oil, wax oil and other fractions. The solid coke is deposited in the coke drum and is periodically decoked to the coke pool.

[0003] The sewage generated by the delayed coking device mostly contains oil and coke powder, especially the sewage generated by the overhead of the vent tower, which has high oil content, serious emulsification and carries coke powder, and the oil and water separation is difficult. The oil content of the sewage after gravity sedimentation often does not meet the standard, and it cannot be sent to the downstream acid water stripping device for treatment or to the sewage treatment plant. The treatment of the coking overhead sewage of the vent tower is one of the technical problems of the device.

[0004] The conventional oil removal method for oily sewage is static oil removal. Static oil removal requires a large-volume storage tank, and for seriously emulsified sewage, a long static time is required. In the case of poor oil removal effect, a demulsifier needs to be injected to promote oil-water layering and accelerate the dehydration process. The above method has high investment and poor effect, and a third medium demulsifier needs to be introduced, which may cause additional pollution.

[0005] Another commonly used method for removing oil from oily sewage is coalescence. Coalescence is a general term for coalescence and corresponding sedimentation process, and the main treatment object is emulsified oil in water. This method takes advantage of the large difference in affinity of oil and water to coalescing materials, and oil droplets are captured by coalescing materials and retained on the material surface and in the voids to form an oil film. When the oil film increases to a certain thickness, the oil film falls off into larger oil droplets under the action of water force and buoyancy. The larger oil droplets after coalescence are easy to separate from water by sedimentation. However, the vent tower overhead sewage carries a large amount of coke powder, which can easily cause the coalescing material to be blocked, so this method is not suitable for treating oily sewage containing solid particles.

[0006] A petroleum refining delayed coking oily sewage treatment system is disclosed in Chinese patent ZL201520308628.8, which comprises a homogenizing buffer tank, a coke powder filter, a rapid filter, an oil-water separator and a treated water storage tank. The oil-water separator is a two-stage oil-water separator, which is composed of a GOS-A oil-water separator and a GOS-B oil-water separator. The technology has the advantages of fast separation speed, short separation time, high separation precision, high quality of separated oil and low water content, and can recycle the oil. However, the system must be combined with multiple treatment methods such as filtration, coalescence and sedimentation to treat the coking oily sewage up to the standard, so it has many treatment procedures, long process flow, many used devices and high complexity. Content of the utility model

[0007] The utility model aims at providing a coking sewage treatment device which uses coke generated in a coking device to realize sewage oil removal and coke powder removal, and overcomes the problems of many treatment procedures and long process flow in the prior art.

[0008] To achieve the above-mentioned purpose, the utility model provides a coking sewage treatment device, which is characterized by comprising an oily sewage treatment tank, wherein the top of the oily sewage treatment tank is provided with a tank top inlet, the bottom is provided with a tank bottom outlet, the side surface is provided with a plurality of tank side flushing ports at different heights in the vertical direction, the other side surface opposite to the tank side flushing port is provided with a plurality of tank side coke discharge ports at different heights in the vertical direction, the inner bottom of the oily sewage treatment tank is provided with a Johnson screen, a coke layer partition plate is arranged above the Johnson screen, one or more one-way anti-mixing hole plates are arranged between the top head of the oily sewage treatment tank and the coke layer partition plate, an oily sewage feeding pipeline is connected to the tank top inlet, an oily sewage feeding valve is arranged on the oily sewage feeding pipeline, a coke powder water feeding pipeline is connected to the tank top inlet or is connected to the tank top inlet after being merged with the oily sewage feeding pipeline, a coke powder water feeding valve is arranged on the coke powder water feeding pipeline, an upper flushing water pipeline is connected to the tank top inlet or is connected to the tank top inlet after being merged with the oily sewage feeding pipeline, an upper flushing water feeding valve is arranged on the upper flushing water pipeline, a side flushing water pipeline is connected to the tank side flushing port, a side flushing water feeding valve is arranged on the side flushing water pipeline, a side coke discharge water pipeline is connected to the tank side coke discharge port, a coke discharge water discharge valve is arranged on the side coke discharge water pipeline, a bottom flushing water pipeline is connected to the tank bottom outlet, a bottom flushing water feeding valve is arranged on the bottom flushing water pipeline, a coke powder water discharge pipeline and an oily sewage discharge pipeline are respectively connected to the tank bottom outlet, and the coke powder water discharge pipeline and the oily sewage discharge pipeline are respectively provided with a coke powder water discharge valve and an oily sewage discharge valve.

[0009] Further technical features of the utility model are that the coke layer partition plate is 500-1200 mm above the Johnson screen.

[0010] The further technical features of the utility model lie in that the one-way anti-mixing hole plate is a flat plate with holes on the top, the hole rate is 5-25%, preferably 10-20%, and the diameter of the holes is 10-15mm; the focus layer baffle is a flat plate with holes on the top, the hole rate is 5-25%, preferably 10-20%, and the diameter of the holes is 5-8mm.

[0011] The further technical features of the utility model lie in that the tank side flushing ports are arranged at least in two, preferably 2-4, wherein at least one is above the Johnson net and adjacent to the Johnson net, and at least one is below the focus layer baffle and adjacent to the focus layer baffle.

[0012] The further technical features of the utility model lie in that the tank side flushing ports are arranged at least in two, preferably 2-4, wherein at least one is above the Johnson net and adjacent to the Johnson net, and at least one is below the focus layer baffle and adjacent to the focus layer baffle.

[0013] The further technical features of the utility model lie in that the one-way anti-mixing hole plate is preferably 1-5 layers, and when arranged in more than two layers, the distance between the adjacent one-way anti-mixing hole plates is 0.5-2m, preferably 1-2m. The purpose is to prevent the backflow and mixing of the fluid medium in the oil-containing sewage treatment tank, so that the liquid flow is more stable and close to plug flow.

[0014] The utility model mainly is used in the treatment of coking sewage, and is especially suitable for the treatment of the oil-containing and coke powder-containing sewage on the top of the coking blow-off tower (contact cooling tower).

[0015] Compared with the prior art, the utility model has the advantages that the utility model discloses a coking sewage treatment device, which forms a filter layer by using the by-product coke of a coking device, sets a Johnson net, a one-way anti-mixing hole plate, a plurality of tank side flushing ports and a plurality of tank side coke discharging ports, realizes the purposes of removing oil and coke powder from the coking sewage through coke loading, filtration and flushing, and thus realizes the standard discharge of the sewage or the sending of the sewage to downstream devices and a sewage treatment plant.

[0016] The application will be further described in detail with reference to the drawings and specific embodiments, but the scope of the application is not limited. DRAWINGS

[0017] Figure 1 is a schematic view of a coking sewage treatment device of the utility model.

[0018] Figure 2 is a schematic view of a one-way anti-mixing hole plate of the utility model.

[0019] Figure 3This is a schematic diagram of a coke layer separator according to the present invention.

[0020] The reference numerals in the figure are:

[0021] 1-Oil-containing wastewater treatment tank; 2-Johnson screen; 3-One-way anti-mixing orifice plate; 4-Top inlet; 5-Bottom outlet; 6-Side flushing port; 7-Side coke discharge port; 8-Coke powder water inlet pipeline; 9-Oil-containing wastewater inlet pipeline; 10-Upper flushing water pipeline; 11-Side flushing water pipeline; 12-Bottom flushing water pipeline; 13-Side coke discharge water pipeline; 14-Coke powder water outlet pipeline; 15-Oil-containing wastewater outlet pipeline; 21-Coke powder water inlet valve; 22-Coke powder water outlet valve; 23-Oil-containing wastewater inlet valve; 24-Oil-containing wastewater outlet valve; 25-Bottom flushing water inlet valve; 26-Side flushing water inlet valve; 27-Coke discharge water outlet valve; 28-Upper flushing water inlet valve; 29-Coke bed baffle. Detailed Implementation

[0022] like Figures 1-3 As shown, the coking wastewater treatment device includes an oily wastewater treatment tank 1. The top of the oily wastewater treatment tank 1 is provided with a top inlet 4, the bottom of the tank is provided with a bottom outlet 5, and multiple side flushing ports 6 are provided at different heights along the vertical direction on the side of the tank. Figure 1 The diagram shows the case with two tank side flushing ports 6. On the opposite side of the tank side flushing ports, multiple tank side coke discharge ports 7 are provided at different heights along the vertical direction. Figure 1 The diagram shows the case with four side coke discharge ports 7 on the tank. A Johnson mesh 2 is installed at the bottom of the oily wastewater treatment tank 1, and a coke layer baffle 29 is installed above the Johnson mesh 2. A multi-layer unidirectional anti-mixing perforated plate 3 is installed between the top end cap of the oily wastewater treatment tank 1 and the coke layer baffle 29. Figure 1 The diagram shows the configuration of two layers of unidirectional anti-mixing perforated plates 3; the oily wastewater inlet pipeline 9 is connected to the tank top inlet 4, and the oily wastewater inlet pipeline 9 is equipped with an oily wastewater inlet valve 23; the coke powder water inlet pipeline 8 is connected to the tank top inlet 4, and the coke powder water inlet pipeline 8 is equipped with a coke powder water inlet valve 21; the upper flushing water pipeline 10 is connected to the tank top inlet 4, and the upper flushing water pipeline 10 is equipped with an upper flushing water inlet valve 28; the bottom flushing water pipeline 12 is connected to the tank bottom outlet 5, and the bottom flushing water pipeline 12 is equipped with a bottom flushing water inlet valve 25; the coke powder water outlet pipeline 14 and the oily wastewater outlet pipeline 15 are respectively connected to the tank bottom outlet 5, and the coke powder water outlet pipeline 14 and the oily wastewater outlet pipeline 15 are respectively equipped with a coke powder water outlet valve 22 and an oily wastewater outlet valve 24.

[0023] The coke layer partition is located 500-1200 mm above the Johnson web.

[0024] The one-way anti-mixing orifice plate and the coke layer baffle are both flat plates with holes, as shown in Figure 2 and Figure 3 .

[0025] There are two side flushing ports in the tank, one of which is located above and adjacent to the Johnson screen 2, and the other is located below and adjacent to the coke layer baffle 29.

[0026] There are four side coke discharge ports in the tank, one of which is located above and adjacent to the Johnson screen 2, one is located below and adjacent to the coke layer baffle 29, one is located above and adjacent to the coke layer baffle 29, and one is located above and adjacent to the uppermost one-way anti-mixing orifice plate 3.

[0027] The one-way anti-mixing orifice plate prevents backflow and mixing of fluid media in the oil-containing sewage treatment tank, making the liquid flow more stable and close to plug flow.

[0028] The operation process of the utility model is divided into three steps: ① loading coke; ② filtering; and ③ flushing (including backwashing and side flushing). All valves are in a closed state before operation.

[0029] Step ① loading coke

[0030] The coke powder water inlet valve 21 and the coke powder water outlet valve 22 are opened, the water containing coke powder in the coke pool of the coking device (the volume content of coke powder is 5% to 30%, and the volume content is preferably 10% to 25%) enters the oil-containing sewage treatment tank 1 through the coke powder water inlet pipeline 8 at the tank top inlet 4. When passing through the Johnson screen 2 at the bottom of the oil-containing sewage treatment tank 1, the coke powder is intercepted on the Johnson screen 2, and a coke powder layer with a certain thickness is gradually formed. The water flows out of the coke powder water outlet pipeline 14 through the tank bottom outlet 5, and then returns to the coke pool or other devices. After the coke powder layer is formed (usually, the thickness of the coke layer is ≥300 mm, and the thickness is preferably 300 to 1000 mm), the coke powder water inlet valve 21 and the coke powder water outlet valve 22 are closed, and the step is stopped, and the step ② filtering is performed.

[0031] Step ② filtering

[0032] The oily wastewater feed valve 23 and the oily wastewater discharge valve 24 are opened, and the oily wastewater enters the oily wastewater treatment tank 1 through the oily wastewater feed pipeline 9 at the tank top inlet 4. The oily wastewater sequentially passes through the one-way anti-mixing hole plate 3 in one direction, forming a stable flow to the filter layer (i.e. the coke powder layer formed in step ① as the filter layer). Due to the bridging between coke particles forming micro channels and the presence of micro pores in the coke powder structure, water can flow smoothly through the channels or pores, while the oil in the water tends to adhere to the surface of the coke particles, thereby achieving the removal of oil from water. In addition, the filter layer can intercept or filter out the coke powder carried by the oily wastewater. After removing the coke powder and oil, the water passes through the tank bottom outlet 5 from the oily wastewater discharge pipeline 15 to the downstream sour water stripping device or other devices. After a period of operation, the coke powder layer gradually accumulates to a certain thickness, and cannot continue to receive the coke powder carried by the oily wastewater; or the coke powder layer has adsorbed a lot of dirty oil, and the pressure difference of the oily wastewater passing through the coke powder layer increases to a certain value (usually ≯ 150 kPa, preferably 20-200 kPa). At this time, the coke layer needs to be flushed and updated, the oily wastewater feed valve 23 and the oily wastewater discharge valve 24 are closed, the step is stopped, and step ③ flushing is performed.

[0033] Step ③ flushing

[0034] First, the bottom flushing water feed valve 25 is opened, and the flushing water enters the oily wastewater treatment tank 1 in the opposite direction through the bottom flushing water pipeline 12, backwashing the coke powder layer formed in the previous step ② to loosen the coke powder layer. Then the valve side flushing water feed valve 26, the coke discharge valve 27 and the upper flushing water feed valve 28 are opened, the upper flushing water enters the oily wastewater treatment tank 1 through the upper flushing water pipeline 10 to prevent the coke powder from moving upward; the lateral flushing water enters the oily wastewater treatment tank 1 through the tank side flushing water pipeline 11 from the tank side flushing port 6, and the coke powder aqueous solution is flushed out and discharged to the coke pool or other devices through the coke discharge pipeline 13. After flushing, the bottom flushing water feed valve 25, the side flushing water feed valve 26, the coke discharge valve 27 and the upper flushing water feed valve 28 are closed.

[0035] After flushing, step ①→②→③ is repeated continuously, and the operation is repeated in this way.

Claims

1. A coking wastewater treatment device, characterized in that: The coking wastewater treatment device includes an oily wastewater treatment tank. The tank has a top inlet and a bottom outlet. Multiple side flushing ports are located at different heights along the vertical direction on the sides. On the opposite side, multiple side coke discharge ports are located at different heights along the vertical direction. A Johnson screen is installed at the bottom of the tank, and a coke layer baffle is installed above the screen. One or more unidirectional anti-mixing perforated plates are installed between the top end cap and the coke layer baffle. An oily wastewater inlet pipeline connects to the top inlet and is equipped with an oily wastewater inlet valve. A coke powder water inlet pipeline connects to the top inlet or merges with the oily wastewater inlet pipeline before connecting to the top inlet. The coke powder water inlet pipeline is equipped with a coke powder water inlet valve. The upper flushing water pipeline is connected to the top inlet of the tank or merges with the oily wastewater inlet pipeline before connecting to the top inlet of the tank. The upper flushing water pipeline is equipped with an upper flushing water inlet valve. The side flushing water pipeline is connected to the side flushing port of the tank. The side flushing water pipeline is equipped with a side flushing water inlet valve. The side coke discharge water pipeline is connected to the side coke discharge port of the tank. The side coke discharge water pipeline is equipped with a coke discharge water outlet valve. The bottom flushing water pipeline is connected to the bottom outlet of the tank. The bottom flushing water pipeline is equipped with a bottom flushing water inlet valve. The coke powder water outlet pipeline and the oily wastewater outlet pipeline are respectively connected to the bottom outlet of the tank. The coke powder water outlet pipeline and the oily wastewater outlet pipeline are respectively equipped with coke powder water outlet valve and oily wastewater outlet valve.

2. The coking wastewater treatment device according to claim 1, characterized in that: The coke layer partition is located 500-1200 mm above the Johnson web.

3. The coking wastewater treatment device according to claim 1, characterized in that: The unidirectional anti-mixing perforated plate is provided in 1-5 layers. When more than 2 layers are provided, the distance between adjacent unidirectional anti-mixing perforated plates is 0.5-2m.

4. The coking wastewater treatment device according to claim 3, characterized in that: The distance between adjacent unidirectional anti-mixing perforated plates is 1-2m.

5. A coking wastewater treatment device according to claim 1, characterized in that: The unidirectional anti-mixing perforated plate is a flat plate with holes on its surface, the perforation rate being 5-25%, and the diameter of the holes being 10-15mm; the coke layer partition plate is a flat plate with holes on its surface, the perforation rate being 5-25%, and the diameter of the holes being 5-8mm.

6. A coking wastewater treatment device according to claim 5, characterized in that: The opening ratio of the unidirectional anti-mixing perforated plate and the coke layer partition is 10-20%.

7. A coking wastewater treatment device according to claim 1, characterized in that: At least two flushing ports are provided on the side of the tank, with at least one located above and adjacent to the Johnson net, and at least one located below and adjacent to the coke layer partition.

8. A coking wastewater treatment device according to claim 7, characterized in that: The tank has 2-4 rinsing ports on its side.

9. A coking wastewater treatment device according to claim 1, characterized in that: At least four coke discharge ports are provided on the side of the tank, of which at least one is located above and adjacent to the Johnson mesh, at least one is located below and adjacent to the coke layer partition, at least one is located above and adjacent to the coke layer partition, and at least one is located above and adjacent to the uppermost one-way anti-mixing perforated plate.

10. A coking wastewater treatment device according to claim 1, characterized in that: The tank has 4-6 coke discharge ports on its side.

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