CN114870559B

CN114870559B - Device and method for collecting and purifying low-boiling-point substances in crude silica gel

Info

Publication number: CN114870559B
Application number: CN202210534730.4A
Authority: CN
Inventors: 蒯红星; 范兵
Original assignee: Huarong Fengshuo Silicon Material Co ltd
Current assignee: Huarong Fengshuo Silicon Material Co ltd
Priority date: 2022-05-17
Filing date: 2022-05-17
Publication date: 2023-03-24
Anticipated expiration: 2042-05-17
Also published as: CN114870559A

Abstract

The invention belongs to the technical field of crude silica gel, and relates to a crude silica gel low-boiling-point substance collecting and purifying treatment device and a treatment method thereof. The gas containing low-boiling-point substances and impurities discharged by a vacuum pump in the production process of the crude silica gel is collected for many times through a primary separator, a secondary separator, a spraying device and the like to obtain a liquid ring body, and the secondary separator which can condense and collect the gaseous ring body in the gas and adsorb and remove the impurities in the gas is designed. And dehydrating the liquid ring body by using a dry compressed air distributor, and then distilling, cracking and rearranging to obtain a mixed ring body mainly containing D4. The invention fully collects, purifies and retreats the ring bodies in the gas, thereby improving the economic value and reducing the environmental pollution.

Description

Device and method for collecting and purifying low-boiling-point substances in crude silica gel

Technical Field

The invention belongs to the technical field of raw silica gel, and relates to a raw silica gel low-boiling-point substance collecting and purifying treatment device and a treatment method thereof.

Background

The crude silicone rubber is polymethyl vinyl siloxane, and a vacuum pump is adopted to perform dehydration and low removal processes in the production process. In the process, a large amount of low-boiling-point substances are taken away by vacuum, are difficult to condense at the front end of the vacuum pump due to low boiling point, and are exhausted by the vacuum pump in a gaseous state. When the gas passes through the vacuum chamber of the vacuum pump, the vacuum pump piston works to generate compression, the air pressure is quickly converted from negative pressure to positive pressure and then to normal pressure, and the volume of the gas is also converted from expansion to compression to normal state. Since the condensation point of the liquid in a vacuum state is lower than that of the liquid in a normal pressure state, the low boiling substances in the gas are easily condensed from a gas state to a liquid state and then collected. However, such low boiling point substances may have mechanical impurities, rust, vacuum pump oil and other impurities after passing through the vacuum pump, and the substances are blackened and yellowed and cannot be directly used, so that the substances need to be removed.

In the production process of the crude silicone rubber, the methyl siloxane mixed ring body needs to be dehydrated under the high-temperature condition by vacuum and the crude silicone rubber needs to be devolatilized under the high-temperature condition by vacuum, a large amount of ring bodies are evaporated and collected for reuse in the process, but part of uncondensed ring body steam is discharged by a vacuum pump, and the part of the ring bodies mainly comprises low-boiling-point ring bodies, mainly D3 (hexamethylcyclotrisiloxane) and a small amount of D4 (octamethylcyclotetrasiloxane), D5 (decamethylcyclopentasiloxane), D6 (dodecamethylcyclohexasiloxane) and the like. In addition, the vacuum off-gas also contains trimethylamine. In this process, the gas containing the ring vapor discharged from the vacuum pump needs to be collected so that the ring therein remains, and the trimethylamine therein needs to be treated. The main component of the ring body after purification treatment is D3, only contains a small amount of D4-D7, the direct use value is not high, and further treatment is needed so as to improve the use value.

How to collect and purify substances such as low-boiling-point substances taken away in the processes of dehydration, low-boiling-point removal and the like of a vacuum pump, and simultaneously improve the use value of a collected ring body, which is a technical problem to be solved urgently by technical personnel in the field.

Disclosure of Invention

In order to solve the technical problems, the invention provides a device and a method for collecting and purifying low-boiling-point substances in crude silica gel, which improve the collecting and purifying efficiency of vacuum tail gas, can remove impurities such as mechanical impurities, rust and vacuum pump oil, can separate trimethylamine in vacuum, and can separate a ring body from water more quickly.

In order to achieve the purpose, the invention adopts the following technical scheme:

the utility model provides a collection purification unit of thing that silica gel is low to boil which characterized in that: the primary separator comprises a tank body, a liquid discharge port, a first gas outlet, a jacket layer and a first gas inlet, the first gas outlet is arranged at the top of the tank body, the bottom of the tank body is funnel-shaped and provided with the liquid discharge port, the first gas inlet is positioned at the middle lower part of the tank body, the inner wall of the tank body is provided with a tangential gas inlet, the first gas inlet is communicated with the tangential gas inlet, the tank wall of the tank body is provided with the jacket layer, and cooling water is introduced into the jacket layer.

Further, the secondary separator comprises a square tank, a cooling column, purification devices and a collecting tank, wherein the cooling column is positioned inside the square tank and fixedly connected with a top plate of the square tank, a plurality of purification devices are obliquely and downwards arranged on the inner walls of two sides of the square tank, two sides of the top of the square tank are respectively provided with a second air outlet, the middle lower parts of two side walls of the square tank are provided with a second air inlet, a cavity is formed inside the cooling column, two side walls of the cooling column are provided with cooling plates which are obliquely and downwards and are hollow inside, the middle part of the inner cavity of the cooling column is vertically provided with a central pipe body, the upper end and the lower end of the central pipe body are provided with openings, and two sides of the central pipe body are respectively provided with a cooling medium inlet; the purification device comprises an upper plate hinged on the inner wall of the square tank, and a torsion spring is arranged at the hinged position of the upper plate and the inner wall of the square tank to keep the upper plate in a downward inclined state; the bottom of the upper plate is provided with a spring and a mesh plate, one end of the spring is fixed on the lower surface of the upper plate, the other end of the spring is fixed on the inner surface of the mesh plate, and a fiber felt is filled between the upper plate and the mesh plate; the collecting tank is positioned on the bottom wall of the bottom of the square tank; the upper plate and the cooling plate are arranged in a staggered and opposite manner. One or more, such as one, two, three or more, springs may be provided in each purification device.

Furthermore, a pull wire is fixedly connected to one side, far away from the inner wall of the square tank, of the upper plate, a cavity layer is arranged between the outer wall and the inner wall of the square tank, a guide groove is formed in one side, close to the inner wall, of the cavity layer, and the pull wire penetrates through the inner wall of the square tank and then is guided to a winding mechanism located on the outer wall of the square tank through the guide groove; the collecting vat is close to square jar both sides inner wall punishment and does not is provided with a division board for the collecting vat is separated for three collection area, is called collecting vat left part region, collecting vat middle part region, collecting vat right part region respectively.

Further, the guide way includes well core rod, side shield and separation blade, and the side shield is two and just is the ring shape, and two side shield intervals are fixed on well core rod, and two side shields obtain fixedly connected with separation blade between the surface.

Furthermore, one side of the upper plate close to the inner wall of the square tank is provided with a through opening, one or more strip-shaped rods are arranged in the through opening, and one side of the upper plate far away from the square tank is of a plate-shaped structure.

Furthermore, one end of the mesh plate, which is adjacent to the inner wall of the square tank, is next to the inner wall of the square tank, and one end of the mesh plate, which is close to the inner wall of the square tank, is provided with a section without meshes.

Further, the spraying device comprises a spraying tank, an air outlet is formed in the top of the spraying tank, a plurality of spraying heads are arranged above the interior of the spraying tank, an inverted V-shaped channel is arranged on the middle lower portion of the interior of the spraying tank, a plurality of through holes are formed in the upper surface of the inverted V-shaped channel, no through hole is formed in the lower surface of the inverted V-shaped channel, and two ends of the inverted V-shaped channel are respectively fixed on the side wall of the spraying tank and communicated with the gas inlet; a liquid buffer device is arranged on the side wall of the lower part inside the spraying tank, and liquid flowing down from the lower surface of the inverted V-shaped channel flows into the liquid buffer device; the left side of the bottom of the spraying tank is provided with a buffer cavity, the buffer cavity is connected with a water pump through a pipeline, and the water pump is communicated with a plurality of spraying heads through a liquid outlet pipe.

Further, the storage tank includes the tank-shaped body, the top of tank-shaped body is provided with manhole and gas vent, the upper portion left side of tank-shaped body is provided with feed valve and dry compressed air import respectively, the lower part is provided with the bleeder valve in the right side of tank-shaped body, the bottom of tank-shaped body is the infundibulate and sets up the drain valve bottom, be provided with dry compressed air distributor at the interior bottom of tank-shaped body, dry compressed air distributor includes dry compressed air inlet main pipe, a plurality of annular intake pipe and dry compressed air inlet branch pipe, annular intake pipe uses dry compressed air inlet branch pipe to arrange as symmetry axis symmetry, a plurality of apertures have been arranged in annular intake pipe, the aperture of aperture is 0.8-1mm.

The invention also provides a collecting and purifying treatment method using the collecting and purifying treatment device for the crude silica gel low-boiling-point substances, which comprises the following specific steps:

introducing gas containing low-boiling-point substances discharged from a vacuum pump in the production process of crude silica gel into a first gas inlet of a primary separator, so that the gas enters along the tangential direction of an inner wall when entering a tank body, the gas forms vortex ascending gas flow along the inner wall in the tank body, and a liquid ring body contained in the gas forms centrifugal force to accelerate separation; meanwhile, the gas is cooled when contacting the inner wall of the tank body, so that part of uncondensed gaseous ring bodies are rapidly condensed into liquid state and fall to the bottom of the tank body, the liquid state ring bodies are obtained by discharging the liquid state ring bodies through a liquid outlet, and the gas is discharged from a first gas outlet;

step (2), gas discharged from the primary separator leaves gaseous ring bodies, the gaseous ring bodies are condensed again after entering the secondary separator to obtain liquid ring bodies and the liquid ring bodies are collected in the middle area of the collecting tank, meanwhile, impurities in the gas are adsorbed by fiber mats, and the liquid ring bodies containing more impurities are extruded and collected in the left area and the right area of the collecting tank;

introducing gas discharged from a second gas outlet of the secondary separator into a spraying device, cleaning the gas to remove trimethylamine, simultaneously cooling and condensing uncondensed gaseous ring bodies by using spraying water to form liquid ring bodies, layering at the bottom of the spraying tank, and collecting the liquid ring bodies from an overflow port;

step (4), the liquid ring body obtained in the step (1), the step (2) and the step (3) is sent into a storage tank, and dehydration, impurity removal and sedimentation are carried out under the action of dry compressed air, so that an anhydrous liquid ring body is obtained;

and (5) distilling the anhydrous liquid ring body obtained in the step (4) to obtain a purified liquid ring body.

And (3) further performing post-treatment on the purified liquid ring body obtained in the step (5), specifically, adding the purified liquid ring body into a reaction kettle to 1/3 of the position, adding strong base KOH with the mass ratio of 0.1-0.3%, slowly heating to 100-120 ℃ under vacuum-0.1 MPA, performing ring opening reaction on the liquid ring body in an alkaline environment to generate polydimethylsiloxane, performing degradation reaction under the action of strong base to break molecular chains to form a new dimethyl siloxane mixed ring body mainly containing D4, and performing distillation and condensation collection to obtain the dimethyl siloxane mixed ring body which can be normally used.

The invention has the following beneficial effects:

(1) The invention designs a device for collecting and purifying low-boiling-point substances in crude silica gel, which collects gas containing the low-boiling-point substances and impurities discharged by a vacuum pump in the production process of the crude silica gel for many times through a primary separator, a secondary separator, a spraying device and the like to obtain liquid ring bodies, and designs a secondary separator which can simultaneously condense and collect gaseous ring bodies in the gas and adsorb and remove the impurities in the gas. The invention fully collects, purifies and retreats the ring bodies in the gas, thereby improving the economic value and reducing the environmental pollution.

(2) The spray device designed by the invention can adsorb and remove trimethylamine in gas, and can reduce disturbance of liquid at the bottom of the spray tank as much as possible, so that the liquid ring body flows out from the overflow port after being layered.

(3) The storage tank adopts the dry compressed air distributor, small bubbles are formed by using dry compressed air, the water-in-oil phenomenon can be eliminated, the water in the liquid ring body can be absorbed more quickly and better, the uniformity of the liquid ring body is improved, and the storage tank has better and faster dehydration effect and efficiency compared with a common nitrogen defoaming mode. Compared with the common annular distributor structure, the shape design of the dry compressed air distributor is more beneficial to discharging liquid in the dry compressed air distributor when the storage tank is cleaned. The nitrogen distributor as provided in CN207478492U cannot exclude the liquid inside, and the dehydration efficiency with nitrogen is inferior to that with dry compressed air as used in the present invention.

(4) The invention retreats the purified liquid ring body, and prepares the ring body with D4 as the main component by cracking rearrangement, thereby greatly improving the use value.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic view of the primary separator of the present invention.

FIG. 2 is a schematic structural view of the secondary separator of the present invention in its operating state.

Fig. 3 is an enlarged view of the region B in fig. 2.

Fig. 4 is a schematic view of the structure of the guide groove.

Fig. 5 is an enlarged view of the area a in fig. 2.

Fig. 6 is a schematic structural view of the upper plate.

FIG. 7 is a schematic view of the secondary separator of the present invention in a compressed state.

Fig. 8 is an enlarged view of a portion of the secondary separator of the present invention in a compressed state.

Fig. 9 is a schematic view of the spray device of the present invention.

FIG. 10 is a schematic view of the sump structure of the present invention.

FIG. 11 is a top view of a compressed air distributor inside a sump of the present invention.

Reference numerals are as follows:

1. a primary separator; 11. a first air outlet; 12. a jacket layer; 13. a tangential gas inlet; 14. a first air inlet; 2. a secondary separator; 21. a central tube body; 22. a cooling medium inlet; 23. a second air outlet; 24. a cooling plate; 25. cooling the column; 26. a partition plate; 27. a bottom wall; 28. collecting tank; 29. an upper plate; 210. an outer wall; 211. a cavity layer; 212. a spring; 213. A mesh plate; 214. a pull wire; 215. a guide groove; 216. a center pole; 217. a side dam; 218. a baffle plate; 219. a winding mechanism; 220. a bar-shaped rod; 3. a spraying device; 31. a spray tank; 32. a shower head; 33. an inverted V-shaped channel; 34. a liquid buffer device; 35. a liquid outlet pipe; 36. a water pump; 37. a buffer chamber; 4. a storage tank; 41. a manhole; 42. a feed valve; 43. A dry compressed air inlet; 44. a pot-shaped body; 45. a liquid level meter; 46. an exhaust port; 47. a dry compressed air distributor; 48. An annular air inlet pipe; 49. a main compressed air inlet pipe is dried; 410. drying the compressed air inlet manifold.

Detailed Description

The invention is further illustrated below with reference to specific figures.

1-2, a silica gel low boiling point substance collecting and purifying treatment device, which comprises a primary separator 1 and a secondary separator 2, wherein the primary separator 1 comprises a tank body, a liquid discharge port, a first gas outlet 11, a jacket layer 12 and a first gas inlet 14, the first gas outlet 11 is arranged at the top of the tank body, the bottom of the tank body is arranged in a funnel shape and is provided with the liquid discharge port, the first gas inlet 14 is positioned at the middle lower part of the tank body, the inner wall of the tank body is provided with a tangential gas inlet 13, the first gas inlet 14 is communicated with the tangential gas inlet 13, and the jacket layer 12 is arranged at the tank wall of the tank body. So set up, through letting in cooling water in to jacket layer 12 for the inner wall cooling of the jar body. When gas enters the tank body, the gas enters the tank body along the tangential direction of the inner wall, forms vortex ascending gas flow along the inner wall in the tank body, forms centrifugal force to liquid ring bodies contained in the gas to accelerate separation, and can increase the contact time of the gas and the inner wall, so that the gas is cooled when contacting with the inner wall of the tank body, and partial uncondensed gaseous ring bodies are rapidly condensed into liquid to fall to the bottom of the tank body, thereby being discharged through a liquid discharge port.

As shown in fig. 2-8, the secondary separator 2 includes a square tank, a cooling column 25, a plurality of purification devices and a collecting tank 28, the cooling column 25 is located inside the square tank and is fixedly connected with a top plate of the square tank, inner walls of two sides of the square tank are provided with a plurality of purification devices in an inclined downward manner, two sides of the top of the square tank are respectively provided with a second air outlet 23, middle lower portions of two side walls of the square tank are provided with a second air inlet, a cavity is formed inside the cooling column 25, two side walls of the cooling column 25 are provided with cooling plates 24 which are inclined downward and are hollow inside, a central tube body 21 is vertically arranged in the middle of the inner cavity of the cooling column 25, openings are formed in the upper end and the lower end of the central tube body 21, and two sides of the central tube body 21 are respectively provided with a cooling medium inlet 22; the purification device comprises an upper plate 29 hinged on the inner wall of the square tank, and a torsion spring is arranged at the hinged position of the upper plate 29 and the inner wall of the square tank to keep the upper plate 29 in an inclined downward state; a spring 212 and a mesh plate 213 are arranged at the bottom of the upper plate 29, one end of the spring 212 is fixed on the lower surface of the upper plate 29, the other end is fixed on the inner surface of the mesh plate 213, and a fiber felt is filled between the upper plate 29 and the mesh plate 213; the collecting tank 28 is positioned on the bottom wall 27 at the bottom of the square tank; the upper plates 29 and the cooling plates 24 are arranged in a staggered manner. One or more, such as one, two, three or more, springs 212 may be provided within each purification device. As shown in fig. 2, the upper plate 29 and the cooling plate 24 overlap each other in a plan view. The gas discharged from the primary separator 1 contains mechanical impurities, gaseous rings which are not removed, etc., and the gas enters from the second gas inlet at the lower part of the square tank, is cooled and blocked by the cooling plates 24, flows to the mesh plate 213 of the purification apparatus again and is blocked by the mesh plate 213 and the fiber mats, etc., and then flows to the adjacent cooling plates 24 again. The residence time of the gas in the square tank is increased by repeatedly changing the flow direction of the gas. At the same time, the gas is cooled further in the process, favouring the further condensation of the gaseous rings into the liquid state for separation and collection in the collection tank 28. When the gas contacts with the mesh plate 213 and the fiber felt, not only the liquid ring body is absorbed by the fiber felt, but also some fine mechanical impurities in the gas are absorbed by the fiber felt, and then the impurity removal and purification effects are achieved. When the liquid rings absorbed in the fibre mat reach saturation, they are collected under the influence of gravity in the collecting tank 28.

Further, a pull wire 214 is fixedly connected to one side of the upper plate 29, which is far away from the inner wall of the square tank, a cavity layer 211 is arranged between the outer wall 210 and the inner wall of the square tank, a guide groove 215 is arranged on one side, which is close to the inner wall, in the cavity layer 211, and the pull wire 214 passes through the inner wall of the square tank and then is guided to a winding mechanism 219 located on the outer wall 210 of the square tank through the guide groove 215; the collecting groove 28 is provided with a partition plate 26 adjacent to the inner walls of the two sides of the square tank, respectively, so that the collecting groove 28 is divided into three collecting areas, which are respectively called a left collecting groove area, a middle collecting groove area and a right collecting groove area. The central region of the collection trough accounts for 60-80% of the total volume of the collection trough 28, and the left and right regions of the collection trough account for 10-20% of the total volume of the collection trough 28, respectively. In normal operation, the purification device is in a state of being inclined downward due to the action of the torsion spring. The condensed liquid ring drips from the end of the upper plate 29 and the end of the cooling plate 24 into the central region of the collection trough. After the fiber felt in the purifying device adsorbs more impurities, the pulling wire 214 is wound by the winding device, so that the upper plate 29 is close to and presses the inner wall of the square tank (as shown in fig. 7-8), and the impurities adsorbed in the fiber felt flow into the left area and the right area of the collecting tank along with the extruded liquid ring body. When the winding device releases the pull wire 214, the purification device is reset to the inclined downward state under the action of the torsion spring, and the fiber felt is restored to the fluffy state under the action of the spring 212 and can be continuously recycled.

The mesh plate 213 is arranged in the purification device, so that the impact of airflow can be born, the airflow impact on the fiber felt is reduced, and the repeated service life of the fiber felt is prolonged. Meanwhile, the mesh plate 213 is arranged, so that fine mechanical impurities and the like in the airflow can be adsorbed by the fiber felt through the meshes. In addition, the mesh plate 213 is made of a harder plate material, which facilitates the installation of the spring 212 between the upper plate 29 and the mesh plate 213, and further facilitates the fiber mat to return to a fluffy state, thereby being capable of being efficiently reused after multiple compressions.

Further, the guide groove 215 includes a central rod 216, two side baffles 217 and a blocking piece 218, the side baffles 217 are circular, the two side baffles 217 are fixed on the central rod 216 at intervals, and the blocking piece 218 is fixedly connected between the outer surfaces of the two side baffles 217. In use, the pull wire 214 passes through the gap between the two side guards 217 and is limited by the stop piece 218, thereby ensuring that the pull wire 214 does not disengage from the guide slot 215.

Furthermore, one side of the upper plate 29 close to the inner wall of the square tank is provided with a through opening, one or more bar-shaped rods 220 (two bar-shaped rods 220 are shown in fig. 6) are arranged in the through opening, and one side of the upper plate 29 far away from the square tank is of a plate-shaped structure. At normal during operation, the air current flows from the lower side top of square jar, and at the liquid ring body of the upper surface condensation of upper plate 29, can receive the impact of ascending air current and be difficult for leaving, wherein probably contains impurity simultaneously, sets up the opening that runs through one side that is close to square jar inner wall at upper plate 29, can make on the part liquid ring body of the upper surface condensation of upper plate 29 flows to the fibrofelt of upper plate 29 below from the opening part to adsorb impurity. In addition, the area of the openings is controlled to be about 5% -10% of the entire area of the upper plate 29 to reduce the amount of gas passing through the positions of the openings. More preferably, the end of the mesh plate 213 adjacent to the inner wall of the square tank is close to the inner wall of the square tank, and the blocking effect of the mesh plate 213 is used to minimize the gas passing through the opening. Meanwhile, a section of mesh plate 213 without meshes can be arranged at one end close to the inner wall of the square tank, so that the gas is further prevented from passing through the opening.

Further, the silica gel low-boiling-point substance collecting and purifying treatment device further comprises a spraying device 3, the spraying device 3 comprises a spraying tank 31, an air outlet is formed in the top of the spraying tank 31, a plurality of spraying heads 32 are arranged above the spraying tank 31, an inverted V-shaped channel 33 is arranged at the middle lower portion inside the spraying tank 31, a plurality of through holes are formed in the upper surface of the inverted V-shaped channel 33, no through hole is formed in the lower surface of the inverted V-shaped channel 33, and two ends of the inverted V-shaped channel 33 are respectively fixed on the side wall of the spraying tank 31 and communicated with the gas inlet; a liquid buffer device 34 is arranged on the side wall of the lower part inside the spraying tank 31, and the liquid flowing down from the lower surface of the inverted V-shaped channel 33 flows into the liquid buffer device 34; a buffer cavity 37 is arranged on the left side of the bottom of the spray tank 31, the buffer cavity 37 is connected with a water pump 36 through a pipeline, and the water pump 36 is communicated with the spray heads 32 through a liquid outlet pipe 35.

The gas discharged from the secondary separator 2 is discharged upward through the through holes on the upper surface of the inverted V-shaped passage 33, and the water pump 36 pumps the water to the shower head 32 to spray the water downward, so that the gas discharged from the secondary separator 2 can be washed and trimethylamine contained therein can be adsorbed. At the same time, it also causes the uncondensed gaseous ring bodies to cool again for condensation and adsorption. The condensed liquid ring body flows to the liquid buffer device 34 along with the water flow through the lower surface of the inverted V-shaped channel 33 and then reaches the bottom of the spray tank 31. The liquid cushioning means 34 may be a bulky fabric, a fiber ball, a sponge, or the like. By the arrangement, disturbance of liquid at the bottom of the spray tank 31 can be reduced as much as possible in the process that water flows downwards. Since the density of water is 1 gram per cubic centimeter and the density of the liquid ring is approximately about 0.95 grams per cubic centimeter, the liquid ring will delaminate from the water. An overflow port (not shown) may be provided at a suitable location at the bottom of the spray tank 31 so that the liquid ring flows out of the overflow port to be collected as the collection amount of the liquid ring increases. The buffer chamber 37 is communicated with the bottom of the spray tank 31 through a pipeline, which can also reduce the disturbance of the water pump 36 to the liquid at the bottom of the spray tank 31 when in operation, thereby minimizing the interference to the liquid ring body and the water layer.

Further, as shown in fig. 10 to 11, the device for collecting, purifying and processing silica gel low boiling point substances further includes a storage tank 4, the storage tank 4 includes a tank-shaped body 44, a manhole 41 and an exhaust port 46 are provided on the top of the tank-shaped body 44, a feed valve 42 and a dry compressed air inlet 43 are respectively provided on the left side of the upper portion of the tank-shaped body 44, a discharge valve is provided on the middle lower portion of the right side of the tank-shaped body 44, a drain valve (not shown) is provided on the bottom of the tank-shaped body 44, a dry compressed air distributor 47 is provided on the inner bottom of the tank-shaped body 44, the dry compressed air distributor 47 includes a dry compressed air inlet main pipe 49, a plurality of annular inlet pipes 48 and a dry compressed air inlet branch pipe 410, the annular inlet pipes 48 are symmetrically arranged with the dry compressed air inlet branch pipe 410 as a symmetry axis, a plurality of small holes are arranged on the annular 48, and the diameter of the small holes is about 0.8 to 1mm. The annular inlet duct 48 is shown in figure 11 as 3 circular ducts of different sizes. The dry compressed air distributor 47 is circular in plan view (shown in fig. 11) and V-shaped in side view (shown in fig. 10). This is provided to facilitate the drainage of liquid entering the interior of the dry compressed air distributor 47 during cleaning of the sump 4. The surface of the body 44 is also provided with a level gauge 45.

The liquid ring body which overflows from the spraying device 3 in layers contains a certain amount of water because of being washed by water spraying. Settling through sump 4 is required. Normally, the liquid ring body needs to settle for 24 hours or more, so that the open water in the liquid ring body settles to the bottom of the tank through self weight, and the liquid ring body can be used after the open water is removed. The density of the liquid ring body is about 0.95-0.97 g/cc, which is very close to the density of water, and the phenomenon of water-in-oil or free water is inevitably generated in the production process, so the aim of removing water is difficult to achieve by normal standing and settling. In addition, the production process of the crude silica gel is a continuous reaction, the content of the produced liquid ring can be different due to the change of factors such as temperature, and the material in the storage tank 4 is uniform and stable if the raw silica gel is only used for standing and sedimentation. In this embodiment, a dry compressed air distributor 47 is added to the storage tank 4, dry compressed air is introduced into the storage tank 4 during the sedimentation process, and the compressed air is uniformly distributed in the material through the dry compressed air distributor 47 and is bubbled by material churning, so that the material is fully and uniformly mixed. Meanwhile, the compressed air can adsorb free moisture in the dispersion after contacting with the liquid ring body, and the water-in-oil phenomenon in the dispersion can be destroyed due to the overturning vibration of the material, so that water particles can collide with each other and condense together to form large-particle water drops to fall and settle, and the layering of water and the liquid ring body is accelerated. In this process, the adsorption principle used is specifically: the air is gas containing saturated water, after the air is acted by a compressor, the volume of the air is shrunk by a plurality of times, due to the incompressibility of the water, a supersaturated state is formed, and then the excess water is condensed and separated by condensation to form dry compressed air. When dry compressed air enters the dry compressed air distributor 47, pressure is released, the volume is expanded by several times, the water content in the relative air is extremely low, and when the air enters the liquid ring body, the moisture is adsorbed for achieving moisture balance, so that the aim of dehydrating the liquid ring body is fulfilled. The storage tank 4 is used for dewatering, so that the uniformity of the liquid ring body can be improved, the dewatering process can be accelerated, and the dewatering is more thorough.

When the storage tank 4 is used for dehydration, the following process can be adopted: standing and settling for 3-4 hours, draining water through a drain valve at the bottom, then introducing dry compressed air for blowing and bubbling for 2-3 hours, so that liquid ring bodies in a storage tank 4 are uniformly mixed, simultaneously a water-in-oil phenomenon can be destroyed, water particles can collide with each other and condense together to form large-particle water drops which fall and settle, standing and settling for 2-4 hours, then discharging water through the drain valve at the bottom again, then introducing dry compressed air for blowing and bubbling again, repeating the steps for 1-2 times, and obtaining the liquid ring bodies without clear water.

The liquid ring body obtained after sedimentation and dehydration in the storage tank 4 is subjected to distillation treatment, and vacuum pump oil and some residual impurities which cannot be settled and the like in the liquid ring body are separated by utilizing the difference of boiling points, so that the purified liquid ring body can be obtained.

The purified liquid ring body is colorless transparent liquid, but because the liquid ring body mainly becomes D3 and only contains a small amount of D4-D7, the liquid ring body has low direct use value, and can be cracked and rearranged to be reformed into the ring body which takes D4 as the main part in order to meet the use requirement. The preparation method comprises the following steps: adding the purified liquid ring body into a reaction kettle to 1/3 of the position, adding strong base KOH with the mass ratio of 0.1-0.3%, and then slowly heating to 100-120 ℃ under vacuum-0.1 MPA. The liquid ring body is subjected to ring opening reaction in an alkaline environment to generate polydimethylsiloxane, a molecular chain is subjected to degradation reaction due to strong alkali action to form a new dimethylsiloxane mixed ring body mainly containing D4, and the dimethyl siloxane mixed ring body can be normally used after being distilled, condensed and collected.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The utility model provides a collection purification unit of thing is hanged down to silica gel which characterized in that: the primary separator comprises a tank body, a liquid discharge port, a first gas outlet, a jacket layer and a first gas inlet, wherein the first gas outlet is formed in the top of the tank body, the bottom of the tank body is arranged in a funnel shape and is provided with the liquid discharge port, the first gas inlet is positioned at the middle lower part of the tank body, the inner wall of the tank body is provided with a tangential gas inlet, the first gas inlet is communicated with the tangential gas inlet, the jacket layer is arranged on the tank wall of the tank body, and cooling water is introduced into the jacket layer; the secondary separator comprises a square tank, a cooling column, purification devices and a collecting tank, wherein the cooling column is positioned inside the square tank and fixedly connected with a top plate of the square tank, a plurality of purification devices are obliquely and downwards arranged on the inner walls of two sides of the square tank, second air outlets are respectively arranged on two sides of the top of the square tank, second air inlets are arranged at the middle lower parts of two side walls of the square tank, a cavity is arranged inside the cooling column, cooling plates which are obliquely and downwards inclined and hollow inside are arranged on two side walls of the cooling column, a central pipe body is vertically arranged in the middle of the inner cavity of the cooling column, openings are formed in the upper end and the lower end of the central pipe body, and cooling medium inlets are respectively arranged on two sides of the central pipe body; the purification device comprises an upper plate hinged to the inner wall of the square tank, and a torsion spring is arranged at the hinged position of the upper plate and the inner wall of the square tank to keep the upper plate in a downward inclined state; a spring and a mesh plate are arranged at the bottom of the upper plate, one end of the spring is fixed on the lower surface of the upper plate, the other end of the spring is fixed on the inner surface of the mesh plate, and a fiber felt is filled between the upper plate and the mesh plate; the collecting tank is positioned on the bottom wall of the bottom of the square tank; the upper plate and the cooling plate are arranged in a staggered and opposite mode.

2. The device for collecting and purifying silica gel low boiling point substance as claimed in claim 1, wherein: a pull wire is fixedly connected to one side, far away from the inner wall of the square tank, of the upper plate, a cavity layer is arranged between the outer wall and the inner wall of the square tank, a guide groove is formed in one side, close to the inner wall, of the cavity layer, and the pull wire penetrates through the inner wall of the square tank and then is guided to a winding mechanism located on the outer wall of the square tank through the guide groove; the collecting tank is provided with a partition plate adjacent to the inner walls of two sides of the square tank respectively, so that the collecting tank is divided into three collecting areas which are respectively called as a left collecting tank area, a middle collecting tank area and a right collecting tank area.

3. The device for collecting, purifying and processing the low boiling point substances in the crude silica gel as claimed in claim 2, wherein: the guide way includes well core rod, side shield and separation blade, the side shield is two and just is ring shape, two the side shield interval is fixed on well core rod, two the side shield obtains fixedly connected with separation blade between the surface.

4. The device for collecting and purifying silica gel low boiling point substance as claimed in any one of claims 1 to 3, wherein: one side that the upper plate is close to square jar inner wall sets up the opening that runs through, there is one or many bar poles in the opening, one side that square jar was kept away from to the upper plate is platelike structure.

5. The device for collecting and purifying silica gel low boiling point substance as claimed in claim 4, wherein: one end of the mesh plate, which is adjacent to the inner wall of the square tank, is next to the inner wall of the square tank, and one end of the mesh plate, which is close to the inner wall of the square tank, is provided with a section without meshes.

6. The device for collecting and purifying silica gel low boiling point substance according to claim 5, wherein: the spraying device comprises a spraying tank, an air outlet is formed in the top of the spraying tank, a plurality of spraying heads are arranged above the interior of the spraying tank, an inverted V-shaped channel is arranged at the middle lower part of the interior of the spraying tank, a plurality of through holes are formed in the upper surface of the inverted V-shaped channel, no through hole is formed in the lower surface of the inverted V-shaped channel, and two ends of the inverted V-shaped channel are respectively fixed on the side wall of the spraying tank and are communicated with an air inlet; a liquid buffer device is arranged on the side wall of the lower part in the spraying tank, and liquid flowing down from the lower surface of the inverted V-shaped channel flows into the liquid buffer device; the left side of the bottom of the spraying tank is provided with a buffer cavity, the buffer cavity is connected with a water pump through a pipeline, and the water pump is communicated with a plurality of spraying heads through a liquid outlet pipe.

7. The device for collecting and purifying silica gel low boiling point substance as claimed in claim 6, wherein: the storage tank comprises a tank body, a manhole and an exhaust port are arranged at the top of the tank body, a feed valve and a dry compressed air inlet are respectively arranged on the left side of the upper portion of the tank body, a discharge valve is arranged on the middle lower portion of the right side of the tank body, the bottom of the tank body is funnel-shaped, a drain valve is arranged at the lowest end of the tank body, a dry compressed air distributor is arranged at the inner bottom of the tank body and comprises a dry compressed air inlet main pipe, a plurality of annular air inlet pipes and a dry compressed air inlet branch pipe, the annular air inlet pipes are symmetrically arranged by taking the dry compressed air inlet branch pipe as a symmetry axis, a plurality of small holes are arranged on the annular air inlet pipes, and the aperture of each small hole is 0.8-1mm.

8. A collection and purification treatment method using the collection and purification treatment apparatus for a low boiling point substance derived from crude silica gel according to claim 7, characterized in that: the method comprises the following specific steps:

introducing gas containing low-boiling-point substances discharged from a vacuum pump in the production process of crude silica gel into a first gas inlet of a primary separator, so that the gas enters along the tangential direction of an inner wall when entering a tank body, the gas forms vortex ascending gas flow along the inner wall in the tank body, and a liquid ring body contained in the gas forms centrifugal force to accelerate separation; meanwhile, the gas is cooled when contacting the inner wall of the tank body, so that part of uncondensed gaseous ring bodies are rapidly condensed into liquid, the liquid falls to the bottom of the tank body and is discharged through a liquid outlet to obtain liquid ring bodies, and the gas is discharged from a first gas outlet;

step (2), gas discharged from the primary separator leaves gaseous ring bodies, the gaseous ring bodies are condensed again after entering a secondary separator to obtain liquid ring bodies and the liquid ring bodies are collected in the middle area of the collecting tank, meanwhile, impurities in the gas are adsorbed by fiber mats, and the liquid ring bodies containing more impurities are extruded and collected in the left area and the right area of the collecting tank;

introducing gas discharged from a second gas outlet of the secondary separator into the spraying device, cleaning the gas to remove trimethylamine, simultaneously cooling and condensing uncondensed gaseous ring bodies by using spraying water to form liquid ring bodies, layering the liquid ring bodies at the bottom of the spraying tank, and collecting the liquid ring bodies from an overflow port;

step (4), feeding the liquid ring bodies obtained in the step (1), the step (2) and the step (3) into the storage tank, and dehydrating, impurity removing and settling under the action of dry compressed air to obtain an anhydrous liquid ring body;

and (5) distilling the liquid ring body without the clear water obtained in the step (4) to obtain a purified liquid ring body.