Settling device for efficiently separating monopentaerythritol and dipentaerythritol

Abstract

The utility model relates to the technical field of sedimentation devices, and discloses a sedimentation device for efficiently separating monopentaerythritol from dipentaerythritol, which comprises a barrel-shaped sedimentation tank, a cylinder is fixed at the center of the upper part of the sedimentation tank, a feed port is formed in the side wall of the cylinder, and a feed pipe is horizontally arranged at the feed port; a surging machine is arranged below the cylinder, a sawtooth-shaped overflow weir is arranged on the side wall of the top of the settling tank, and an annular collecting tank is arranged outside the overflow weir. According to the scheme, the cylinder, the surging machine and the annular collecting tank are arranged in the settling tank in a combined manner, so that a solution containing monopentaerythritol and dipentaerythritol mixed crystals is conveniently settled and dispersed into a solution containing crystals with different particle sizes, the liquid level fluctuation is small in the whole settling separation process, the grading settling force is soft, and the crystal settling efficiency is effectively improved. And the whole settling separation process can be continuously carried out, the energy consumption is low, the settling separation efficiency of the monopentaerythritol and the dipentaerythritol is effectively improved, and rapid separation and purification of the monopentaerythritol and the dipentaerythritol are realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to a settling device technical field, concretely relates to a single, double pentaerythritol high -efficient separation's settling device. BACKGROUND

[0002] In the co-production process of pentaerythritol and double pentaerythritol, although double pentaerythritol is a byproduct but has significant economic value, and in the production process is mixed with the main product single pentaerythritol, which brings challenges to the effective separation of both. Although the existing settling tank separation technology has been widely used in this scene, but there are still the following technical problems: (1) low settling efficiency: because the double pentaerythritol crystal is extremely small (0.045mm), similar to flour, the single pentaerythritol crystal is relatively thick (0.115-1.18mm), the thick single pentaerythritol crystal settles faster in the solution, and the double pentaerythritol crystal settles slower, with the increase of the double pentaerythritol crystal concentration on the surface of the settling tank, the solution becomes viscous, and the small single pentaerythritol crystal settles extremely slowly in the solution, even if the settling speed difference principle of the settling tank is used, the small single and double pentaerythritol crystals are still difficult to separate effectively in a short time. A large amount of double pentaerythritol remains in the single pentaerythritol product, reducing the recovery rate and sales price of double pentaerythritol (double pentaerythritol remaining in the single pentaerythritol product is sold according to the price of single pentaerythritol product, which significantly reduces the economic benefit), and also affects the quality of single pentaerythritol. (2) large design difference of settling tank: each company strictly keeps the design of the settling tank secret, and the designed settling tank has great difference, such as tank shape, size, internal structure, etc. These differences directly affect the settling effect and separation efficiency. The unreasonable design of the settling tank may cause uneven settling speed, local precipitation too fast or too slow, thereby further reducing the separation effect.

[0003] The applicant currently uses a square settling tank, and the overflow weir is on both sides of the square tank, so that the settling tank has a settling dead zone; in addition, the distance between the feed inlet and the overflow weir is inconsistent, resulting in a difference in the settling time of the crystal solution; further, the existing settling tank feed pipe is directly inserted into the liquid surface 1m below, and there is fluid inertia, which can directly send a large amount of single and double pentaerythritol crystals to the bottom of the settling tank, so that natural gravity settling cannot be achieved, and at the same time, the feed solution is bound by the pipe, which cannot allow all the crystals to be uniformly dispersed, affecting the uniformity of the settling, resulting in a large amount of double pentaerythritol product existing in the single pentaerythritol product, which cannot be separated out, reducing the separation effect.

[0004] Therefore, a single, double pentaerythritol high-efficiency separation settling device is developed, which not only effectively makes up for the shortcomings of the prior art, but also improves the settling efficiency and separation effect, thereby improving the recovery rate and purity of double pentaerythritol, reducing the production cost, and improving the product competitiveness. UTILITY MODEL CONTENTS

[0005] The utility model aims to provide a sedimentation device for efficiently separating monopentaerythritol and dipentaerythritol, so as to solve the technical problem of low sedimentation efficiency of the existing sedimentation device.

[0006] To achieve the above-mentioned purpose, the utility model adopts the following technical scheme: a sedimentation device for efficiently separating monopentaerythritol and dipentaerythritol, comprising a barrel-shaped sedimentation tank, a cylinder fixed at the center of the upper part of the sedimentation tank, a feed port opened on the side wall of the cylinder, and a feed pipe horizontally arranged at the feed port; a surge machine is provided below the cylinder, a serrated overflow weir is provided on the top side wall of the sedimentation tank, and an annular collecting tank is provided outside the overflow weir.

[0007] The principles and advantages of this solution are:

[0008] 1. This solution facilitates the horizontal entry of a solution containing mono- and dipentaerythritol mixed crystals into the cylinder from the feed pipe by providing a cylinder and a horizontal feed pipe. The solution is decelerated and dispersed by the collision with the liquid surface. The dispersed solution flows to the inner wall of the cylinder, where it is blocked and further decelerated. Subsequently, under the constraint of the cylinder, the mixed crystals naturally settle below the cylinder. During the entire feeding process, the cylinder acts as a "force-unloading disperser". On the one hand, it reduces the flow rate of the solution, facilitating the slow dispersion and sedimentation of the mixed crystals in the solution. On the other hand, it slows down the impact of the solution on the liquid surface in the sedimentation tank, facilitating the separate sedimentation of crystals of different particle sizes and reducing foaming on the liquid surface.

[0009] 2. This solution utilizes a surge mechanism to evenly disperse naturally settling crystals of varying sizes toward the periphery of the sedimentation tank, opening up gaps between crystals for a uniform distribution throughout the sedimentation tank. This also mitigates the impact and drag of crystals during sedimentation, helping to reduce solution viscosity. Furthermore, the surge mechanism can cause the mixed crystal solution to surge upward at a constant frequency, allowing fine monopentaerythritol and dipentaerythritol crystals to gently rise to the surface of the solution and overflow into the annular collection tank. Larger monopentaerythritol crystals, due to gravity being greater than the upward force of the fluid, continue to settle to the bottom.

[0010] 3. This solution sets up an annular collection tank to facilitate the overflow of the solution in the sedimentation tank into the annular collection tank, thereby effectively separating crystals of different particle sizes, and ultimately achieving the separation of monopentaerythritol and dipentaerythritol crystals to improve the purity and quality of their respective products.

[0011] 4. Compared to the low settling efficiency of existing settling devices, this solution, by combining a cylinder, surge generator, and an annular collection tank within the settling tank, facilitates the sedimentation and dispersion of a solution containing mixed crystals of monopentaerythritol and dipentaerythritol into solutions containing crystals of varying particle sizes. The entire settling and separation process results in minimal liquid level fluctuations and gentle, graded settling forces, effectively improving crystal settling efficiency. Furthermore, the entire settling and separation process can be performed continuously, effectively improving the settling and separation efficiency of monopentaerythritol and dipentaerythritol, and enabling rapid separation and purification of both.

[0012] 5. Compared with the flat overflow, which cannot be absolutely level and results in differences in 360° overflow, this solution adopts a serrated overflow weir to make the solution overflow level, thereby achieving uniform overflow within the 360° range, without any sedimentation dead zone, and further improving the sedimentation uniformity and sedimentation effect.

[0013] Preferably, as an improvement, the sedimentation tank is a "U"-shaped circular tank with cylindrical side walls and a round bottom.

[0014] Technical effect: This solution adopts the above-mentioned setting, which makes it easier for the coarse crystals that settle to the bottom to be evenly distributed at the bottom of the sedimentation tank, and the round bottom also makes it easier for the crystals that settle to the bottom to be discharged in a concentrated manner.

[0015] Preferably, as an improvement, the feed end of the feed pipe and the upper edge of the cylindrical side wall are both higher than the upper edge of the side wall of the sedimentation tank.

[0016] Technical effect: This scheme adopts the above-mentioned setting to facilitate solution feeding, and by setting a cylinder higher than the upper edge of the side wall of the sedimentation tank, it effectively restrains the impact force of the feed from shaking the liquid surface, and also improves the weakening effect of the liquid surface on the impact force of the feed, thereby facilitating the natural sedimentation of mixed crystals in the feed.

[0017] Preferably, as an improvement, the feed port is 5 to 10 cm lower than the upper edge of the side wall of the sedimentation tank.

[0018] Technical effect: Through long-term experiments, the applicant found that when the feed port is 5 to 10 cm lower than the upper edge of the sedimentation tank side wall (i.e., the overflow liquid level), the liquid surface has a better effect of weakening the impact force of the feed, effectively increasing the natural sedimentation rate of the crystals in the feed, thereby improving the sedimentation efficiency, and at the same time reducing the formation of foam.

[0019] Preferably, as an improvement, defoaming nozzles are provided inside the cylinder and on the edge of the sedimentation tank, the defoaming nozzles are connected to defoaming pipes, and the defoaming pipes are connected to the desalted water tank.

[0020] Technical effect: The sedimentation separation solution is prone to foaming, which has a great impact on the sedimentation separation. This solution installs defoaming nozzles in the central cylinder of the sedimentation tank and on the edge of the sedimentation tank, sprays desalted water, eliminates foam, and improves the crystal sedimentation separation effect and efficiency.

[0021] Preferably, as an improvement, the surge motor is a variable frequency surge motor, which includes a casing, an impeller, a rotating shaft and a variable frequency motor. The variable frequency motor is fixed on a bracket located above the sedimentation tank. The output shaft of the variable frequency motor is fixedly connected to the rotating shaft, and the rotating shaft is fixedly connected to the impeller. A cylindrical casing is provided around the impeller, and the side walls of the casing are fixed to the inner wall of the sedimentation tank. The casing is open at the top and bottom.

[0022] Technical Effect: This solution uses the above-mentioned configuration to activate the variable frequency motor to drive the impeller, pushing the liquid upward, gently pushing the naturally settled mixed crystals toward the edge of the sedimentation tank for dispersion and graded sedimentation, thereby improving the sedimentation effect. The installation of the shell effectively limits the scope and extent of the liquid surge, preventing the surge force from penetrating the shell and affecting the naturally settling crystals at the edge of the sedimentation tank (i.e., the space between the inner wall of the sedimentation tank and the shell).

[0023] Preferably, as an improvement, the cross-section of the shell is an "inverted trapezoid".

[0024] Technical effect: This solution adopts the above-mentioned setting, which facilitates the shell to form a certain divergence angle, effectively guiding the solution to disperse to the edge of the sedimentation tank, facilitating the natural sedimentation of crystals and improving the crystal sedimentation efficiency.

[0025] Preferably, as an improvement, the bottom of the rotating shaft extends to the bottom of the sedimentation tank, and a scraper plate is fixedly connected to the bottom of the rotating shaft.

[0026] Technical effect: This solution adopts the above-mentioned setting, which makes it easy for the motor to drive the impeller to surge and disperse the crystals in the liquid, and at the same time drive the bottom scraper to concentrate the crystals settled to the bottom center of the sedimentation tank for centralized discharge and collection.

[0027] Preferably, as an improvement, a rectangular opening is provided at the bottom of the sedimentation tank, which is connected to a scraper located below the sedimentation tank. The scraper is arranged at an angle, and the lower end of the scraper is located below the bottom of the sedimentation tank. A crystal discharge port is provided at the top of the scraper, and a crystal collection bucket is placed below the crystal discharge port; there is a tiny gap between the scraper and the bottom edge of the scraper.

[0028] Technical effect: This solution adopts the above-mentioned setting, which makes it easy to scrape out the crystals settled at the bottom of the sedimentation tank, filter them dry and collect them. Specifically, in this solution, the crystals and solution at the bottom of the sedimentation tank are continuously discharged into the scraper, and are gradually filtered dry as the scraper conveys them, obtaining crystals with a lower water content. And the applicant found through experiments that compared with the use of a screw conveyor, which is easy to break the crystals and has a very high water content, this solution uses a scraper to convey the crystals. The relatively static conveying not only effectively avoids the damage of the crystal structure, but also plays a role in filtering out water during the scraper lifting process through the gap between the scrapers, effectively filtering the water in the crystals, and further improving the purity and quality of the crystals.

[0029] Preferably, as an improvement, a washing nozzle is provided in the middle of the scraper.

[0030] Technical effect: This scheme adopts the above-mentioned setting, which makes it convenient to use the mother liquor obtained after filtering the upper overflow solution to wash the crystals through the washing nozzle during the transmission process, thereby improving the cleanliness of the crystals. The use of saturated filtered mother liquor for washing also avoids the crystals from dissolving and losing weight during the washing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic structural diagram of a sedimentation device for efficient separation of mono- and dipentaerythritol in Example 1 of the present utility model. DETAILED DESCRIPTION

[0032] The following is further described in detail through specific implementation methods:

[0033] The figure marks in the drawings of the specification include: sedimentation tank 1, feed pipe 11, rectangular opening 12, overflow weir 13, annular collecting tank 2, cylinder 2, variable frequency motor 31, rotating shaft 32, impeller 33, shell 34, scraper 4, scraper 5, and washing nozzle 51.

[0034] Example 1

[0035] Basically as attached Figure 1 Shown is a sedimentation device for the efficient separation of mono- and dipentaerythritol, comprising a barrel-shaped sedimentation tank 1. The sedimentation tank 1 is a U-shaped circular trough with cylindrical sidewalls and a round or conical bottom. A serrated overflow weir 13 is located at the top of the sidewall of the sedimentation tank 1. This weir 13 has a serrated shape. Compared to a flat overflow weir 13, which cannot be absolutely horizontal and results in variability in overflow across 360°, this solution utilizes a serrated overflow weir 13 to ensure surface level overflow, resulting in uniform overflow across 360°. An annular collection trough 2 is located outside the overflow weir 13 to collect the solution overflowing from the overflow weir 13. The annular collection trough 2 has a liquid outlet pipe at its bottom and an overflow pipe on its side. The bottom of the overflow pipe is located below the lowest point of the serrated weir teeth to prevent overflow from the annular collection trough 2 from returning to the sedimentation tank 1.

[0036] A cylinder 2 is fixed to the center of the upper part of the sedimentation tank 1. The bottom of the cylinder 2 is open, and the top wall is provided with a hole for the rotating shaft 32 and the defoaming pipe to pass through below. The side wall of the cylinder 2 is provided with a feed port, and a feed pipe 11 is provided horizontally at the feed port. The feed end of the feed pipe 11 and the upper edge of the side wall of the cylinder 2 are both higher than the upper edge of the side wall of the sedimentation tank 1. The feed port is 5 to 10 cm lower than the upper edge of the side wall of the sedimentation tank 1, which is convenient for the liquid level to weaken the impact of the feed, facilitate the natural sedimentation of the feed, and improve the sedimentation efficiency. As an improvement, the number of feed pipes 11 in this scheme is two, which are located on both sides of the cylinder 2, so as to increase the feed amount and improve the sedimentation efficiency. Defoaming nozzles are provided in the cylinder 2 and on the edge of the sedimentation tank 1. The defoaming nozzles are connected to the defoaming pipe, and the defoaming pipe is connected to the desalted water tank to facilitate the desalted water to eliminate the foam formed on the liquid surface.

[0037] A surge machine is provided in the middle of the sedimentation tank 1, below the cylinder 2. As an improvement, the surge machine is a variable frequency surge machine, which includes a housing 34, an impeller 33, a rotating shaft 32, and a variable frequency motor 31. The variable frequency motor 31 is fixed to a bracket located above the sedimentation tank 1. The output shaft of the variable frequency motor 31 is fixedly connected to the rotating shaft 32, which is fixedly connected to the impeller 33. A cylindrical housing 34 is provided around the impeller 33. The sidewalls of the housing 34 are fixed to the inner wall of the sedimentation tank 1, and the housing 34 is open at the top and bottom. In order to further promote the upward surging liquid to disperse toward the edge of the sedimentation tank 1, the cross-section of the housing 34 is an "inverted trapezoidal" shape, which facilitates guiding the liquid to surge toward the edge of the sedimentation tank 1 and then settle. The bottom of the rotating shaft 32 extends to the bottom of the sedimentation tank 1. A scraper plate 4 is fixedly connected to the bottom of the rotating shaft 32 so that when the rotating shaft 32 rotates, the scraper plate 4 is driven to concentrate the crystals settled to the bottom to the bottom center of the sedimentation tank 1.

[0038] A rectangular opening 12 is provided at the bottom of the sedimentation tank 1 to facilitate the discharge of crystals that have settled in the center of the bottom of the tank 1. Rectangular opening 12 is connected to a scraper 5 located below the sedimentation tank (this is an existing device, and its structure is not described in detail here). The scraper 5 is tilted, with its bottom end located below the rectangular opening 12 for receiving the material. A crystal discharge port is provided at the top of the scraper 5, and a crystal collection bucket (not shown) is placed below the crystal discharge port to collect the crystal product. A slight gap exists between the scraper blades of the scraper 5 and the bottom edge, allowing the scraper 5 to collect the crystals and filter them during transportation.

[0039] In order to further improve the cleanliness of the crystals, a washing nozzle 51 is provided in the middle of the scraper conveyor 5 of this scheme, so that the mother liquor obtained after filtering the upper overflow solution can be used to wash the crystals through the washing nozzle 51 during the transmission process, thereby improving the cleanliness of the crystals and preventing the crystals from dissolving and losing weight during the washing process with clean water. Specific implementation method:

[0041] A solution containing mixed mono- and dipentaerythritol crystals enters cylinder 2 horizontally from feed pipe 11. First, it slows down and disperses due to the impact of the liquid surface. The dispersed solution flows to the inner wall of cylinder 2, where it is blocked and further decelerated. Subsequently, under the restraint of cylinder 2, the mixed crystals naturally settle downward. Throughout the feeding process, cylinder 2 acts as a "force-removing disperser," reducing the flow rate of the solution, facilitating the slow dispersion and sedimentation of the mixed crystals in the solution. Furthermore, it mitigates the impact of the solution on the liquid surface in settling tank 1, facilitating the separate sedimentation of crystals of different particle sizes and reducing foaming on the liquid surface. During this process, a defoaming nozzle continuously sprays desalted water to eliminate foam on the liquid surface, preventing it from affecting the sedimentation and separation of the mixed crystals.

[0042] The naturally settled mixed crystals surge upward under the impetus of the variable frequency surge motor and disperse toward the edge of the sedimentation tank 1 under the guidance of the shell 34. During the dispersion process, the fine monopentaerythritol and dipentaerythritol crystals gently rise to the surface of the solution with the solution and then overflow into the annular collection tank 2 with the solution, while the coarse monopentaerythritol crystals continue to settle to the bottom because the gravity is greater than the rising force of the fluid, thereby achieving the separation of crystals of different particle sizes.

[0043] The crystals that settle to the bottom are evenly dispersed across the trough floor. The agitation of the scraper 4 gathers the scattered crystals toward the center of the trough floor and is continuously discharged through the rectangular opening 12 to the bottom of the scraper 5. As the scraper 5 lifts and transports the crystals upward, they gradually lose water through filtration, effectively reducing the water content of the crystals while preventing damage to the crystal structure. When transported to the middle of the scraper 5, mother liquor sprayed from the elutriation nozzle 51 elutriates the crystals, further improving the cleanliness of the crystals when they are discharged from the top of the scraper 5, thereby enhancing product quality.

[0044] Specifically, the purity of the crystals obtained by this solution after drying is as high as 98.5% or more, and the water content of the crystals at the end of the scraper is as low as 10-20%.

[0045] The above description is merely an embodiment of the present invention, and the commonly known specific technical solutions and / or features of the solution are not described in detail here. It should be noted that for those skilled in the art, without departing from the technical solution of the present invention, several variations and improvements can be made, which should also be considered as the scope of protection of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection claimed in this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A sedimentation device for efficient separation of mono- and dipentaerythritol, characterized by: It includes a barrel-shaped sedimentation tank, with a cylinder fixed at the center of the upper part of the sedimentation tank, a feed port opened on the side wall of the cylinder, and a feed pipe horizontally arranged at the feed port; a surge machine is arranged below the cylinder, a sawtooth overflow weir is arranged on the top side wall of the sedimentation tank, and an annular collection tank is arranged outside the overflow weir; a liquid outlet pipe is arranged at the bottom of the annular collection tank, and an overflow pipe is arranged on the side, and the bottom of the overflow pipe is lower than the lowest point of the teeth of the sawtooth overflow weir; The surge machine is a variable frequency surge machine, which includes a casing, an impeller, a rotating shaft and a variable frequency motor. The variable frequency motor is fixed on a bracket located above the sedimentation tank. The output shaft of the variable frequency motor is fixedly connected to the rotating shaft, and the rotating shaft is fixedly connected to the impeller. A cylindrical casing is provided around the impeller, and the side walls of the casing are fixed to the inner wall of the sedimentation tank. The casing is open at the top and bottom. The cross-section of the casing is an "inverted trapezoid".

2. The sedimentation device for efficient separation of mono- and dipentaerythritol according to claim 1, characterized in that: The sedimentation tank is a "U"-shaped circular tank with cylindrical side walls and a round bottom.

3. The sedimentation device for efficient separation of mono- and dipentaerythritol according to claim 1, characterized in that: The feed end of the feed pipe and the upper edge of the cylinder side wall are both higher than the upper edge of the sedimentation tank side wall, and the feed port is 5 to 10 cm lower than the upper edge of the sedimentation tank side wall.

4. The sedimentation device for efficient separation of mono- and dipentaerythritol according to claim 1, characterized in that: Defoaming nozzles are provided inside the cylinder and on the edge of the sedimentation tank. The defoaming nozzles are connected to defoaming pipes, and the defoaming pipes are connected to the desalted water tank.

5. The sedimentation device for efficient separation of mono- and dipentaerythritol according to claim 4, characterized in that: The bottom of the rotating shaft extends to the bottom of the sedimentation tank, and a scraper plate is fixedly connected to the bottom of the rotating shaft.

6. A sedimentation device for efficient separation of monopentaerythritol and dipentaerythritol according to any one of claim 1, characterized in that: A rectangular opening is provided at the bottom of the sedimentation tank, which is connected to a scraper located below the sedimentation tank. The scraper is set at an angle, with the bottom end of the scraper located below the bottom of the sedimentation tank. A crystal discharge port is provided at the top of the scraper, and a crystal collection bucket is placed below the crystal discharge port. There is a tiny gap between the scraper and the bottom edge of the scraper.

7. The sedimentation device for efficient separation of monopentaerythritol and dipentaerythritol according to claim 6, characterized in that: A washing nozzle is provided in the middle of the scraper conveyor.

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