Turpentine recovery system of pulping and paper-making factory

Abstract

The utility model relates to the technical field of pulping and paper-making factory equipment, and particularly discloses a turpentine recovery system of a pulping and paper-making factory, which comprises an evaporation heavy-dirt condensate water tank, the lower part of the evaporation heavy-dirt condensate water tank is connected with a heavy-dirt water pump through a pipeline, and the heavy-dirt water pump is connected with a condensate water cooler through a pipeline. The condensate water cooler is connected with the bottom of the turpentine separator through a pipeline, an overflow pipe is arranged at the top of the turpentine separator, a regulating valve is arranged on the overflow pipe, and the overflow pipe is connected with the turpentine tank through a pipeline; the bottom of the turpentine separator is connected with a U-shaped pipe, the liquid outlet end of the U-shaped pipe is connected with the heavy-pollution condensate water tank, and a U-shaped elbow of the U-shaped pipe is higher than the ground relative to the liquid inlet end and the liquid outlet end of the U-shaped pipe, so that turpentine can be separated through an overflow pipe at the top of the turpentine separator, but water cannot reach the top of the tank. According to the utility model, turpentine in the evaporation heavy sewage tank can be separated, and the evaporation efficiency of the evaporation system is improved.

Description

Technical Field

[0001] This utility model relates to the field of pulp and paper mill equipment, specifically to a turpentine recovery system for pulp and paper mills. Background Technology

[0002] Turpentine oil is a mixture of various components. The specific types and amounts of these components depend on the type of pine tree, the geographical location of the tree, and the harvest season. Turpentine oil produced in the United States is primarily composed of α-pinene (75% to 85%) and varying amounts of β-pinene (up to 3%), camphene (4% to 15%), limonene (dipentene, 5% to 15%), 3-carene, and terpinene. Turpentine oil is the name used for many semi-fluid oleoresins obtained from coniferous trees. The substance obtained from these trees consists of 75% to 90% resin and 10% to 25% oil. When distilled, it produces turpentine oil (C... 10 Turpentine oil is a mixture of terpenes and essential oils, the percentage of which varies depending on geographical location, tree species, and distillation process. In pulp and paper mills, wood is cooked to produce black liquor, and the concentration process generates a large amount of heavily polluted condensate. The highly concentrated odorous gas from the cooking process passes through a cyclone separator and is then cooled to 85°C by a condenser. The condensed liquid goes to the heavily polluted wastewater tank, while the condensate is discharged to the heavily polluted condensate tank in the evaporation section. The remaining highly concentrated odorous gas is cooled to 50°C by a condenser before being sent to the highly concentrated odorous gas collection system. When the raw material for cooking is pine wood, the heavily polluted condensate tank in the evaporation section may contain turpentine oil (boiling point 150-170°C, density 860-875 kg / m³). 3 During long-term operation of the system, turpentine may accumulate in the tank, forming a stable "turpentine + water" two-phase layer, which is detrimental to the long-term operation of the evaporation system. Typically, crude sulfate turpentine is often contaminated with sulfides to varying degrees, and its market value is usually high, so it is best sold rather than burned. If the sulfide content is too high or the terpene content is of poor quality, incineration may be the only feasible disposal method. Utility Model Content

[0003] The purpose of this invention is to provide a turpentine recovery system for pulp and paper mills, which can separate turpentine from the heavy wastewater evaporation tank, improve the evaporation efficiency of the evaporation system, and save the steam consumption required for evaporation.

[0004] To achieve the above objectives, this utility model provides the following technical solution:

[0005] A turpentine recovery system for a pulp and paper mill includes an evaporation condensate tank containing heavy waste condensate, the lower part of which is connected to a heavy wastewater pump via a pipeline, the heavy wastewater pump via a pipeline to a condensate cooler, the condensate cooler via a pipeline to the bottom of a turpentine separator, an overflow pipe at the top of the turpentine separator, a regulating valve on the overflow pipe, and the overflow pipe via a pipeline to a turpentine tank.

[0006] The bottom of the turpentine separator is connected to a U-shaped pipe, on which a control valve is installed. The outlet end of the U-shaped pipe is connected to a heavy waste condensate tank. The U-shaped bend of the U-shaped pipe is higher than the inlet and outlet ends of the U-shaped pipe from the ground. The height difference between the lowest point of the inner wall of the U-shaped bend and the bottom of the turpentine separator is H3. H3 and the lower limit of the oil-water interface inside the turpentine separator satisfy the following conditions:

[0007] H1*ρ 松 +H2ρ 水 =H3ρ 水 ,

[0008] H2 is the height difference between the lower limit of the oil-water interface inside the turpentine separator and the bottom of the turpentine separator; H1 is the height difference between the lower limit of the oil-water interface inside the turpentine separator and the top of the turpentine separator; ρ 松 ρ is the density of turpentine oil. 水 The density of water;

[0009] When the turpentine separator is filled with liquid and the oil-water interface in the turpentine separator is not greater than the lower limit of the oil-water interface, the aqueous phase cannot flow into the heavy waste condensate tank through the U-shaped pipe.

[0010] Optionally, the lower limit of the oil-water interface in the turpentine separator is the lower limit of the liquid level sight glass window on the turpentine separator.

[0011] Optionally, the U-shaped tube includes a first horizontal tube connected to the bottom outlet end of the turpentine separator, a first vertical tube extending upward from the other end of the first horizontal tube, a second horizontal tube connected to the first vertical tube, and a second vertical tube extending downward from the other end of the second horizontal tube. The second vertical tube is connected to the heavy waste condensate tank through a horizontal tube.

[0012] Furthermore, the joints of the first horizontal pipe, the first vertical pipe, the second horizontal pipe, and the second vertical pipe all use rounded corners.

[0013] Optionally, the lower part of the heavy waste condensate tank is connected to a heavy wastewater pump via a pipeline, and the top of the heavy waste condensate tank is connected to a high-concentration odor removal system via a pipeline.

[0014] Optionally, the top of the turpentine tank is connected via a pipeline to a high-concentration odor removal system.

[0015] Optionally, the height difference between the highest point of the inner wall of the U-shaped elbow and the bottom of the turpentine separator is H4, and the upper limit of the oil-water interface in the turpentine separator is the upper limit of the liquid level sight glass window on the turpentine separator. H4 and the upper limit of the oil-water interface in the turpentine separator satisfy the following conditions:

[0016] H5*ρ 松 +H6ρ 水 =H4ρ 水 ,

[0017] H6 is the height difference between the upper limit of the oil-water interface inside the turpentine separator and the bottom of the turpentine separator; H5 is the height difference between the upper limit of the oil-water interface inside the turpentine separator and the top of the turpentine separator; ρ 松 ρ is the density of turpentine oil. 水 This is the density of water.

[0018] Compared with the prior art, the present invention has at least the following beneficial effects:

[0019] 1. It can separate turpentine from the heavy wastewater evaporation tank, improve the evaporation efficiency of the evaporation system, and save the steam consumption required for evaporation.

[0020] 2. The separated turpentine oil has very little water content and can be blended with methanol extracted from SOG as fuel for incinerators, saving natural gas or light diesel oil consumption in incinerators.

[0021] 3. This separation system can easily separate turpentine. However, when the turpentine separator is filled with liquid and the oil-water interface in the turpentine separator is not greater than the lower limit of the oil-water interface, the aqueous phase cannot flow into the heavy waste condensate tank through the U-shaped pipe.

[0022] 4. The lower limit of the oil-water interface in the turpentine separator is the lower limit of the liquid level sight glass window on the turpentine separator, and the upper limit of the oil-water interface in the turpentine separator is the upper limit of the liquid level sight glass window on the turpentine separator. This ensures that within the visible range of the liquid level sight glass window on the turpentine separator, oil is prevented from flowing into the heavy condensate tank through the U-shaped pipe when the lower limit of the oil-water interface in the turpentine separator is lower than the lower limit of the liquid level sight glass window on the turpentine separator, or water is prevented from entering the turpentine tank through the overflow pipe at the top of the turpentine separator when the upper limit of the oil-water interface in the turpentine separator is higher than the upper limit of the liquid level sight glass window on the turpentine separator. Attached Figure Description

[0023] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0024] Figure 1 This is a schematic diagram of the system of this utility model;

[0025] Figure 2 This is a schematic diagram of the turpentine separator and U-shaped tube of this utility model;

[0026] Figure 3 This is a schematic diagram showing the correspondence between the oil-water interface height and the height of the U-shaped tube in the turpentine oil separator of this utility model. Detailed Implementation

[0027] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0028] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when “comprising” and / or “including” are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0029] A turpentine recovery system for a pulp and paper mill, such as Figure 1 As shown, the system includes an evaporating heavy waste condensate tank 1 containing heavy waste condensate. The lower part of the evaporating heavy waste condensate tank 1 is connected to a heavy wastewater pump 2 via a pipeline. The heavy wastewater pump 2 is connected to a condensate cooler 3 via a pipeline. The condensate cooler 3 is connected to the bottom of a turpentine separator 4 via a pipeline. The top of the turpentine separator 4 is equipped with an overflow pipe 4.1, which has a regulating valve. The overflow pipe 4.1 is connected to a turpentine tank 7 via a pipeline. The top of the turpentine tank 7 is connected to a high-concentration odor removal system via a pipeline. The bottom of the turpentine tank 7 is connected to a turpentine pump 8 via a pipeline. The bottom of the turpentine separator 4 is connected to a U-shaped pipe 10, which has a control valve. The outlet end of the U-shaped pipe 10 is connected to a heavy waste condensate tank 5. The lower part of the heavy waste condensate tank 5 is connected to the heavy wastewater pump 2 via a pipeline. The top of the heavy waste condensate tank 5 is connected to a high-concentration odor removal system via a pipeline.

[0030] like Figure 2As shown, the U-shaped tube 10 of this invention includes a first horizontal tube 10.1 connected to the bottom outlet of the turpentine separator, a first vertical tube 10.2 extending upwards from the other end of the first horizontal tube 10.1, a second horizontal tube 10.3 connected to the first vertical tube 10.2, and a second vertical tube 10.4 extending downwards from the other end of the second horizontal tube 10.3. A horizontal tube is connected to the tail of the second vertical tube 10.4, which is connected to the heavy waste condensate tank 5. Further, the connections between the first horizontal tube 10.1, the first vertical tube 10.2, the second horizontal tube 10.3, and the second vertical tube 10.4 all use rounded corners. In this invention, the heavy waste condensate from the evaporating heavy waste condensate tank 1 is pumped by the heavy waste water pump 2 to the condensate cooler 3 to be cooled to 55°C, and then enters the turpentine separator 4 for separation by density difference. Since oil is less dense than water, the oil layer on the upper layer of turpentine separator 4 exits from the top and enters turpentine tank 7 for temporary storage, and is then transported away by turpentine pump 8. The water layer on the lower layer of turpentine separator 4 exits from the bottom and enters heavy waste condensate pump tank 5, and is then pumped back to the heavy wastewater tank of the evaporation section by heavy wastewater pump 2.

[0031] The lower limit of the oil-water interface in the turpentine separator is the lower limit of the liquid level sight glass window on the upper part of the turpentine separator: oil-water interface a;

[0032] The upper limit of the oil-water interface in the turpentine separator is the upper limit of the liquid level sight glass window on the turpentine separator: oil-water interface c;

[0033] By using the height difference H3 between the lower surface of the second horizontal pipe 10.3 of the U-shaped pipe 10 (i.e., the highest point a' of the water) and the bottom of the turpentine separator 4, when there is more oil phase and less water phase in the turpentine separator 4, the water phase is prevented from flowing into the heavy waste condensate tank 5 through the second horizontal pipe 10.3, thus preventing turpentine from being carried in the water phase.

[0034] like Figure 3 As shown, the specific principle is as follows: when the turpentine separator 4 is filled with liquid, and the oil-water interface in the turpentine separator 4 is lower than or equal to the height of point a, the height difference between the upper surface of the water phase in the turpentine separator 4 and the bottom of the turpentine separator 4 is H1, and the height difference between the upper surface of the water phase in the turpentine separator 4 and the top of the turpentine separator 4 is H2.

[0035] Based on the principle that the product of the density and height of the liquid in the turpentine separator 4 (the static pressure of the mixed liquid) is equal to the product of the density and height of the liquid in the U-tube 10 (the static pressure of water).

[0036] H1*0.867+H2=H3; 0.867 is the approximate density value of turpentine.

[0037] If H1 increases and H2 decreases, it is equivalent to an increase in the oil phase and a decrease in the water phase in the turpentine separator 4. The static pressure of the mixed liquid in the turpentine separator 4 decreases, which in turn reduces the static pressure of the water phase in the U-shaped tube 10. Therefore, the height of the water phase in the U-shaped tube 10 is lower than the lower surface of the second horizontal tube 10.3, and the water phase cannot flow into the heavy waste condensate tank 5 through the second horizontal tube 10.3, thus preventing turpentine from being carried in the water phase.

[0038] If the turpentine separator 4 is filled with liquid, and there is less oil and more water in the turpentine separator 4, the oil-water interface in the turpentine separator 4 is greater than the height of point a, causing H1 to decrease and H2 to increase. The static pressure of the mixed liquid in the turpentine separator 4 increases, which leads to an increase in the static pressure of the water phase in the U-shaped tube 10. Therefore, the height of the water phase in the U-shaped tube 10 is higher than the lower surface of the second horizontal tube 10.3. The water phase flows into the heavy waste condensate tank 5 through the second horizontal tube 10.3, avoiding the water phase being carried away when the oil phase is discharged from the overflow pipe 4.1.

[0039] The principle is as follows: the height difference between the highest point of the inner wall of the U-shaped bend and the bottom of the turpentine separator is H4. The upper limit of the oil-water interface in the turpentine separator is the upper limit of the liquid level sight glass window on the turpentine separator. H4 and the upper limit of the oil-water interface in the turpentine separator satisfy the following conditions:

[0040] H5*ρ 松 +H6ρ 水 =H4ρ 水 ,

[0041] H6 is the height difference between the upper limit of the oil-water interface inside the turpentine separator and the bottom of the turpentine separator; H5 is the height difference between the upper limit of the oil-water interface inside the turpentine separator and the top of the turpentine separator; ρ 松 ρ is the density of turpentine oil. 水 This is the density of water.

[0042] If the turpentine separator 4 is filled with liquid, and the upper limit of the oil-water interface in the turpentine separator is higher than the upper limit of the liquid level sight glass window on the turpentine separator, water can be prevented from entering the turpentine tank through the overflow pipe of the turpentine separator in an invisible state.

[0043] When in use, since the top of the turpentine separator 4 is equipped with an overflow pipe 4.1, when the turpentine separator 4 is full of liquid, the liquid overflows from the overflow pipe 4.1. At this time, the control valve on the U-shaped pipe 10 is opened to allow the water phase in the turpentine separator 4 to flow back into the U-shaped pipe. When the turpentine separator 4 is completely filled with liquid, the water cannot be discharged from the top of the turpentine separator 4 when the water level at the oil-water interface in the turpentine separator 4 is lower than or equal to the height of point a.

[0044] This also ensures that the oil-water interface of the mixed liquid is within the visible range of the turpentine separator's sight glass window, preventing oil from flowing into the heavy condensate tank and water from flowing into the overflow pipe.

[0045] In this invention, the heavy condensate stored in the heavy evaporation condensate tank 1 is transported by the heavy wastewater pump 2 to the condensate cooler 3 to be cooled to 55°C, and then enters the turpentine separator 4 for separation by density difference. Turpentine and heavy waste condensate are allowed to separate into layers in turpentine separator 4. Since turpentine is less dense than water, the upper layer of turpentine in turpentine separator 4 flows out from the top overflow pipe 4.1 and enters turpentine tank 7 for temporary storage. It is then pumped by turpentine pump 8 to be mixed with methanol extracted from SOG as fuel for the incinerator, thereby saving the incinerator's natural gas or light diesel consumption, or it can be temporarily stored and sold. When turpentine overflows from the top of turpentine separator 4, the control valve on U-shaped pipe 10 is opened, and the lower layer of heavy waste condensate in turpentine separator 4 flows out from the bottom and is pumped back to the evaporation heavy waste condensate tank 1 in the evaporation section by heavy wastewater pump 2. The high-concentration odor gas flowing out from the top of heavy waste condensate tank 5 and turpentine tank 7 is treated by the high-concentration odor gas system.

[0046] The above description is only a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any transformations or substitutions that can be understood by those skilled in the art within the technical scope disclosed in this utility model should be included within the scope of this utility model.

Claims

1. A turpentine recovery system for a pulp and paper mill, comprising an evaporation condensate tank containing heavy waste condensate, the lower part of the evaporation condensate tank being connected to a heavy wastewater pump via a pipeline, the heavy wastewater pump being connected to a condensate cooler via a pipeline, and the condensate cooler being connected to the bottom of a turpentine separator via a pipeline, characterized in that, The turpentine separator is equipped with an overflow pipe at the top, and a regulating valve is installed on the overflow pipe. The overflow pipe is connected to the turpentine tank through a pipeline. The bottom of the turpentine separator is connected to a U-shaped pipe, on which a control valve is installed. The outlet end of the U-shaped pipe is connected to a heavy waste condensate tank. The U-shaped bend of the U-shaped pipe is higher than the inlet and outlet ends of the U-shaped pipe from the ground. The height difference between the lowest point of the inner wall of the U-shaped bend and the bottom of the turpentine separator is H3. H3 and the lower limit of the oil-water interface inside the turpentine separator satisfy the following conditions: H1*p 松 +H2p 水 =H3ρ 水 , H2 is the height difference between the lower limit of the oil-water interface inside the turpentine separator and the bottom of the turpentine separator; H1 is the height difference between the lower limit of the oil-water interface inside the turpentine separator and the top of the turpentine separator; ρ 松 ρ is the density of turpentine oil. 水 The density of water; When the turpentine separator is filled with liquid and the oil-water interface in the turpentine separator is not greater than the lower limit of the oil-water interface, the aqueous phase cannot flow into the heavy waste condensate tank through the U-shaped pipe.

2. The turpentine recovery system for a pulp and paper mill according to claim 1, characterized in that, The lower limit of the oil-water interface in the turpentine separator is the lower limit of the liquid level sight glass window on the turpentine separator.

3. The turpentine recovery system for a pulp and paper mill according to claim 1, characterized in that, The U-shaped pipe includes a first horizontal pipe connected to the bottom outlet of the turpentine separator, a first vertical pipe extending upward from the other end of the first horizontal pipe, a second horizontal pipe connected to the first vertical pipe, and a second vertical pipe extending downward from the other end of the second horizontal pipe. The second vertical pipe is connected to the heavy waste condensate tank through a horizontal pipe.

4. The turpentine recovery system for a pulp and paper mill according to claim 3, characterized in that, The joints of the first horizontal pipe, the first vertical pipe, the second horizontal pipe, and the second vertical pipe all use rounded corners.

5. The turpentine recovery system for a pulp and paper mill according to claim 1, characterized in that, The lower part of the heavy waste condensate tank is connected to a heavy wastewater pump via a pipeline, and the top of the heavy waste condensate tank is connected to a high-concentration odor removal system via a pipeline.

6. The turpentine recovery system for a pulp and paper mill according to claim 1, characterized in that, The top of the turpentine tank is connected via a pipeline to a system for removing high-concentration odors.

7. The turpentine recovery system for a pulp and paper mill according to claim 1, characterized in that, The height difference between the highest point of the inner wall of the U-shaped bend and the bottom of the turpentine separator is H4. The upper limit of the oil-water interface in the turpentine separator is the upper limit of the liquid level sight glass window on the turpentine separator. H4 and the upper limit of the oil-water interface in the turpentine separator satisfy the following conditions: H5*p 松 +H6p 水 =H4ρ 水 , H6 is the height difference between the upper limit of the oil-water interface inside the turpentine separator and the bottom of the turpentine separator; H5 is the height difference between the upper limit of the oil-water interface inside the turpentine separator and the top of the turpentine separator; ρ 松 ρ is the density of turpentine oil. 水 This is the density of water.

Images