Circulating spraying system for ethylene glycol

Abstract

The invention belongs to the technical field of polyester production equipment, and discloses an ethylene glycol circulating spraying system which comprises a spraying pipe, a scraper condenser, a liquid discharging pipe, a liquid sealing groove, a circulating pipe I, a circulating pipe II, a jacket spraying pipe, a conical cap type distribution plate I, an additional pipe I and an additional pipe II. The scraper condenser comprises a horizontal cylinder, a vertical cylinder and a conical cap type distribution plate II; the conical cap type distribution plate II is positioned inside the vertical cylinder; the output end of the spray pipe is inserted into the vertical cylinder, and the orifice of the output end of the spray pipe faces the top of the conical cap type distribution plate II; the conical cap type distribution plate I is positioned above the conical cap type distribution plate II; the jacket spraying pipe is sleeved on the spraying pipe; one ends of the circulating pipe I and the circulating pipe II are respectively connected with the liquid seal tank, and the other ends are respectively connected with the input end of the spraying pipe. The online cleaning device can clean the spraying pipe, the jacketed spraying pipe and the inner pipe of the circulating pipe between the valve a and the spraying pipe and between the valve b and the spraying pipe online, and blockage is avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of polyester production equipment and relates to a circulating spraying system of ethylene glycol. Background Art

[0002] In the polyester production process, the tail gas produced by the polycondensation reaction needs to be extracted by the vacuum system. However, there are a lot of substances entrained in the tail gas. Some of these substances will precipitate and accumulate on the pipe wall of the vacuum system as the temperature decreases in the vacuum system, which can easily cause blockage of the vacuum system pipeline and is not easy to handle. In serious cases, it may lead to forced shutdown. Therefore, before the tail gas enters the vacuum system, it usually passes through the scraper condenser to remove as much condensable gas and entrained substances as possible, and then the non-condensable gas enters the vacuum system, thereby solving the problem of vacuum system pipeline blockage.

[0003] The specific method of removing the condensable substances in the scraper condenser is to spray ethylene glycol so that the ethylene glycol and the gas phase substances flow alternately and absorb the condensable gas and capture the entrained matter. The used ethylene glycol is filtered and then circulated and sprayed through a circulation pump; however, among the captured substances, the smaller substances are not easy to be removed, especially the powder-like substances. These substances remain in the ethylene glycol, which will make the ethylene glycol gradually "dirty" and increase the possibility of blockage in the ethylene glycol circulation system pipeline.

[0004] In order to solve the above problems, the document (Process Improvement of Vacuum System of Polyester Device [J], Synthetic Fiber, 2009 (6): 46-48.) provides a circulating spray system of ethylene glycol, such as Figure 1 As shown, the circulation spraying system of ethylene glycol includes a scraper condenser, a lower liquid pipe, a liquid seal tank 46, a buffer tank 47, a spray pipe 1, a circulation pipe I, a circulation pipe II, a circulation pipe III, a circulation pipe IV, a circulation pipe V, a replenishing pipe, an overflow pipe, a production pipe I, a production pipe II, a switching pipe I, and a switching pipe II;

[0005] The scraper condenser comprises a horizontal cylinder 45, a vertical cylinder 12, a connecting plate II 9, and a conical cap distribution plate II 6. The vertical cylinder 12 is fixedly connected to the upper part of the horizontal cylinder 45, and the two are connected; a gas phase port is provided at the upper part of the horizontal cylinder 45, and a discharge port is provided at the lower part of the horizontal cylinder 45; the conical cap distribution plate II is an umbrella-shaped structure, a cone is provided at the top of the conical cap distribution plate II 6, the conical cap distribution plate II 6 is located inside the vertical cylinder 12, the concave surface of the conical cap distribution plate II 6 faces downward, and the conical cap distribution plate II 6 is fixedly connected to the vertical cylinder 12 through the connecting plate II 9; a through hole I is provided on the circumferential surface of the vertical cylinder 12, the output end of the spray pipe 1 is inserted into the interior of the vertical cylinder 12 through the through hole I, and the orifice of the output end of the spray pipe 1 is aligned with the cone; a vacuum suction port is provided at the top of the vertical cylinder 12, and the vacuum system is connected to the vacuum suction port;

[0006] The discharge port of the scraper condenser is connected to the liquid seal tank 46 through a lower liquid pipe; the liquid seal tank 46 is used to receive the circulating ethylene glycol and filter it;

[0007] One end of the circulation pipe I is connected to the bottom of the liquid seal groove 46, and the other end is connected to the input end of the spray pipe 1; along the direction from the liquid seal groove 46 to the spray pipe 1, the circulation pipe I is provided with valve s 41, filter I 38, pump I 36, valve n 32, plate heat exchanger I 30 and valve b 14 in sequence; pump I 36 is used to transport the ethylene glycol in the liquid seal groove 46 to the spray pipe 1; plate heat exchanger I 30 is used to cool the ethylene glycol;

[0008] One end of the circulation pipe II is connected to the bottom of the liquid seal groove 46, and the other end is connected to the input end of the spray pipe 1; along the direction from the liquid seal groove 46 to the spray pipe I1, the circulation pipe II is provided with valve r 40, filter II 39, pump II 37, valve q35, plate heat exchanger II 31, valve a 13 in sequence; pump II 37 is used to transport the ethylene glycol in the liquid seal groove 46 to the spray pipe 1; plate heat exchanger II 31 is used to cool the ethylene glycol;

[0009] Assume that there is a connection point A 52 on the circulation pipe I between the pump I 36 and the valve n 32, and there is a connection point B 53 on the circulation pipe I between the valve n 32 and the plate heat exchanger I 30; Assume that there is a connection point C 54 on the circulation pipe II between the pump II 37 and the valve q 35, and there is a connection point D 55 on the circulation pipe II between the valve q 35 and the plate heat exchanger II 31; one end of the switching pipe I is connected to the connection point A 52, the other end of the switching pipe I is connected to the connection point D 55, and the switching pipe I is provided with a valve o 33; one end of the switching pipe II is connected to the connection point B 53, the other end of the switching pipe I is connected to the connection point C 54, and the switching pipe II is provided with a valve p 34;

[0010] Assume that there is a connection point E 56 on the circulation pipe I between the plate heat exchanger I 30 and the valve b 14, and assume that there is a connection point F 57 between the plate heat exchanger II 31 and the valve a 13; one end of the production pipe I is connected to the connection point E 56, and the other end is connected to the outside world; along the direction from the connection point E 56 to the outside world, the production pipe I is provided with valves k 27 and m 29 in sequence; the input end of the production pipe II is connected to the connection point F 57, and the output end of the production pipe II is connected to the production pipe I between the valves k 27 and m 29; the production pipe II is provided with a valve l 28;

[0011] Assume that there is a connection point G 58 on the circulation pipe II between the valve r 40 and the filter II 39, and a connection point H 59 is provided on the circulation pipe II between the connection point F 57 and the valve a13; one end of the circulation pipe III is connected to the connection point G 58, and the other end is connected to the connection point H 59; a jacket heat exchanger 44 is provided on the circulation pipe III; the jacket heat exchanger 44 is used to heat ethylene glycol; a valve u 43 is provided on the circulation pipe III between the jacket heat exchanger 44 and the connection point G 58, and a valve w 49 is provided on the circulation pipe III between the jacket heat exchanger 44 and the connection point H 59;

[0012] Assume that a connection point I 60 is provided on the circulation pipe I between the valve s 41 and the filter I 38, and a connection point J 61 is provided between the connection point E 56 and the valve b14; one end of the circulation pipe IV is connected to the connection point I 60, and the other end is connected to the circulation pipe II between the valve u 43 and the jacket heat exchanger 44; the circulation pipe IV is provided with a valve t 42; one end of the circulation pipe V is connected to the connection point J 61, and the other end is connected to the circulation pipe III between the valve w 49 and the jacket heat exchanger 44; the circulation pipe V is provided with a valve x 50;

[0013] Assume that there is a connection point K62 on the circulation pipe III between the valve w49 and the jacket heat exchanger 44, there is a connection point L63 on the production pipe I between the valve k27 and the valve m29, and there is a connection point M64 on the production pipe I between the valve m29 and the discharge outlet of the production pipe I; one end of the supplementary pipe is connected to the connection point K62, and the other end of the supplementary pipe is connected to the connection point L63; the buffer tank 47 is arranged on the supplementary pipe; one end of the overflow pipe is connected to the buffer tank 47, and the other end is connected to the connection point M64 (the other end of the overflow pipe can also be directly connected to the outside world).

[0014] When there is too much ethylene glycol in the liquid seal tank 46 (ethylene glycol vapor in the tail gas is captured and falls into the circulation system), the total amount of ethylene glycol in the circulation system is kept stable by controlling the opening and closing of valves k 27, valve l 28 and valve m 29;

[0015] The spray pipe 1, scraper condenser, downpipe, liquid seal groove 46 and circulation pipe I form an ethylene glycol spray system; the spray pipe 1, scraper condenser, downpipe, liquid seal groove 46 and circulation pipe II form another ethylene glycol spray system; during normal use, only one ethylene glycol spray system is in use, and the other ethylene glycol spray system is on standby; in order to prevent accidents, in addition to using two sets of ethylene glycol spray system accidents, the switching pipe I and switching pipe II are designed to prevent the problem of failure of ethylene glycol spraying due to damage to some pipelines.

[0016] When online cleaning of the circulation pipe I is required, the circulation pipe I, the circulation pipe IV, the partial section of the circulation pipe III, and the circulation pipe V are controlled by the valve to form an online cleaning circulation system, thereby realizing the cleaning of the circulation pipe I, while the circulation pipe II is still involved in the ethylene glycol spraying; when online cleaning of the circulation pipe II is required, the circulation pipe II and the circulation pipe III are controlled by the valve to form an online cleaning circulation system, thereby realizing the cleaning of the circulation pipe II, while the circulation pipe I is still involved in the ethylene glycol spraying; as set above, the online cleaning of the circulation pipes I and II can be realized;

[0017] During the online cleaning process, ethylene glycol in the circulating pipe that is participating in the spraying can be introduced into the circulating pipe that is being cleaned online through the replenishing pipe, so that the circulating pipe that is being cleaned online can be further filled with ethylene glycol (when ethylene glycol overflows from the buffer tank 47 through the overflow pipe, it is filled).

[0018] However, the ethylene glycol circulating spraying system provided in the document has a fatal problem, that is, only the circulating pipe I and the circulating pipe II can be cleaned, while the inner pipe of the spray pipe 1, the inner pipe of the circulating pipe II between the valve a 13 and the spray pipe, and the inner pipe of the circulating pipe I between the valve b 14 and the spray pipe cannot be cleaned. As a result, the particles that cannot be filtered by the fine filter and the substances partially dissolved in the ethylene glycol will slowly precipitate and adhere to the inner pipe of the spray pipe I, making the pipe diameter smaller, affecting the flow rate and the spraying effect.

[0019] Therefore, it is of great significance to study a circulating spray system of ethylene glycol to solve the above problems. Summary of the invention

[0020] The purpose of the invention is to solve the problems existing in the prior art and provide a circulating spraying system for ethylene glycol.

[0021] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0022] A circulating spray system for ethylene glycol comprises a spray pipe, a scraper condenser, a downpipe, a liquid seal tank, a circulating pipe I and a circulating pipe II; the scraper condenser comprises a horizontal cylinder and a vertical cylinder; the output end of the spray pipe is inserted into the vertical cylinder; one end of the circulating pipe I and the circulating pipe II are respectively connected to the liquid seal tank, and the other end is respectively connected to the input end of the spray pipe; the circulating pipe I is provided with a valve s, a pump I and a plate heat exchanger I; the circulating pipe II is provided with a valve r, a pump II and a plate heat exchanger II; the valve s is located between the plate heat exchanger I and the liquid seal tank, and the valve r is located between the plate heat exchanger II and the liquid seal tank; the circulating spray system for ethylene glycol further comprises a jacketed spray pipe, an additional pipe I and an additional pipe II;

[0023] The jacket spray pipe is sleeved on the spray pipe; one end of the jacket spray pipe is sealed and connected to the spray pipe, and the other end is inserted into the interior of the vertical cylinder;

[0024] Assume that there is a connection point N between the spray pipe and the plate heat exchanger I on the circulation pipe I; one end of the additional pipe I is connected to the jacket spray pipe, and the other end is connected to the connection point N; a valve b is provided on the circulation pipe I between the connection point N and the spray pipe;

[0025] Assume that there is a connection point O between the spray pipe and the plate heat exchanger II on the circulation pipe II; one end of the external pipe II is connected to the connection point O, and the other end is used to introduce hot ethylene glycol above 120° C.; a valve f is provided on the external pipe II.

[0026] When it is necessary to clean the inside of the spray pipe, the valve is controlled so that cold ethylene glycol (the plate heat exchanger can also cool down the ethylene glycol) continues to spray in the vertical cylinder through the jacket spray pipe, and then hot ethylene glycol above 120°C is sprayed in the vertical cylinder after passing through the inside of the spray pipe, and the inside of the spray pipe is cleaned. Since the top of the vertical cylinder of the scraper condenser is connected to the vacuum system, when spraying with hot ethylene glycol, the hot ethylene glycol will easily volatilize under vacuum, thereby failing to achieve the purpose of capturing condensable gases and entrained materials; therefore, the present invention sets the cold ethylene glycol spray position above the hot ethylene glycol spray position, so that the cold ethylene glycol covers the hot ethylene glycol and the condensable gases and entrained materials in the vertical cylinder, thereby not reducing the spraying effect and achieving online cleaning of the inside of the spray pipe.

[0027] As the preferred technical solution:

[0028] In the above-mentioned circulating spray system for ethylene glycol, a vacuum suction port is provided on the top of the vertical cylinder, and the vacuum suction port is used to connect with the vacuum system; a discharge port is provided at the bottom of the horizontal cylinder, and the discharge port is connected with the liquid sealing tank through a lower liquid pipe; the liquid sealing tank is used to receive and filter ethylene glycol.

[0029] The ethylene glycol circulating spraying system as described above further comprises a cone-hat type distribution plate I and a cone-hat type distribution plate II;

[0030] The cone-hat type distribution plate II is located inside the vertical cylinder; the output end of the spray pipe is inserted into the vertical cylinder, and the orifice of the output end of the spray pipe faces the top of the cone-hat type distribution plate II; the cone-hat type distribution plate II is used to evenly spray the ethylene glycol sprayed from the spray pipe in the vertical cylinder;

[0031] The cone-hat type distribution plate I is located above the cone-hat type distribution plate II; a through hole II is provided on the cone-hat type distribution plate I, and the output end of the spray pipe passes through the through hole II and is fixedly connected to the through hole II.

[0032] A circulating spray system for ethylene glycol as described above, wherein the circulating spray system for ethylene glycol further comprises an additional pipe III, an additional pipe IV, an additional pipe V and an atomizing nozzle;

[0033] Assume that there is a connection point P between the spray pipe and the plate heat exchanger II on the circulation pipe II; one end of the additional pipe III is connected to the jacket spray pipe, and the other end is connected to the connection point P; a valve a is provided on the circulation pipe II between the connection point P and the spray pipe;

[0034] Assume that there is a connection point Q between the spray pipe and the plate heat exchanger I on the circulation pipe I; one end of the external pipe IV is connected to the connection point Q, and the other end is used to pass hot ethylene glycol above 120°C; a valve e is provided on the external pipe IV;

[0035] The additional pipe I is provided with a valve d, and the additional pipe III is provided with a valve c;

[0036] The atomizing nozzle is located inside the vertical cylinder and above the conical cap type distribution plate I; one end of the external tube V is inserted into the vertical cylinder and connected to the atomizing nozzle, and the other end of the external tube V is used to introduce fresh ethylene glycol I; a valve y is provided on the external tube V;

[0037] When the inner wall of the jacket spray pipe needs to be cleaned, hot ethylene glycol flows in the jacket spray pipe and cold ethylene glycol flows in the spray pipe. At this time, the hot ethylene glycol spray position is above the cold ethylene glycol and cannot be effectively covered; therefore, it is necessary to open valve y to allow fresh ethylene glycol I to enter the vertical cylinder for spraying, thereby covering the hot ethylene glycol. In addition, fresh ethylene glycol I can also reduce the concentration of impurities in the circulating ethylene glycol to reduce adverse effects such as scaling;

[0038] When there are additional pipes I, II, III and IV, hot ethylene glycol can be introduced into the circulation pipe I to clean the inside of the spray pipe (in this case, the cold ethylene glycol in the circulation pipe II goes to the jacket spray pipe), or hot ethylene glycol can be introduced into the circulation pipe II to clean the inside of the spray pipe (in this case, the cold ethylene glycol in the circulation pipe I goes to the jacket spray pipe); similarly, hot ethylene glycol can be introduced into the circulation pipe I to clean the inside of the jacket spray pipe (in this case, the cold ethylene glycol in the circulation pipe II goes to the spray pipe), or hot ethylene glycol can be introduced into the circulation pipe II to clean the inside of the jacket spray pipe (in this case, the cold ethylene glycol in the circulation pipe I goes to the spray pipe).

[0039] In the above-mentioned ethylene glycol circulating spraying system, a connection point R is provided on the external pipe I between the valve d and the spraying pipe, one end of the external pipe III is connected to the connection point R, and the other end is connected to the connection point P.

[0040] A circulating spray system for ethylene glycol as described above, wherein the circulating spray system for ethylene glycol further comprises an additional pipe VI, an additional pipe VII and an additional pipe VIII;

[0041] One end of the external pipe II not connected to the connection point O and one end of the external pipe IV not connected to the connection point Q are connected to one end of the external pipe VI through a tee pipe, and the external pipe VII and the external pipe VIII are connected to the other end of the external pipe VI through a tee pipe; a valve g is provided on the external pipe VII, and a valve h is provided on the external pipe VIII; the end of the external pipe VII not connected to the external pipe VI is used to introduce hot ethylene glycol at 170° C. to 180° C., and the end of the external pipe VIII not connected to the external pipe VI is used to introduce fresh ethylene glycol II;

[0042] A mixer is provided on the external pipe VI, and the mixer is used to mix the hot ethylene glycol at 170°C to 180°C and the fresh ethylene glycol II into the hot ethylene glycol at 120°C to 140°C; a thermometer is provided on the mixer, and the thermometer is used to detect the temperature inside the mixer;

[0043] During the polyester polymerization process, hot ethylene glycol at 170℃~180℃ will be produced as a by-product. In order to achieve recycling, hot ethylene glycol at 170℃~180℃ is introduced. However, the temperature of the hot ethylene glycol is too high and it will have an adverse effect on the pipeline if it is directly introduced. Therefore, fresh ethylene glycol II is added for neutralization and cooling. A large amount of fresh ethylene glycol can be introduced first. However, by gradually reducing the proportion of fresh ethylene glycol II added, the temperature of the hot ethylene glycol in the mixer is gradually increased from a lower temperature to 120℃~140℃.

[0044] The ethylene glycol circulating spraying system as described above further comprises a connecting plate I, a connecting plate II, an expanding pipe, a fixing ring and a plurality of fixing plates;

[0045] The fixing ring is sleeved on the jacket spray pipe and is fixedly connected to the jacket spray pipe; the fixing ring is fixedly connected to the inner wall of the vertical cylinder through the connecting plate I to better fix the jacket spray pipe;

[0046] The cone-hat type distribution plate II is fixedly connected to the inner wall of the vertical cylinder through the connecting plate II to better fix the cone-hat type distribution plate II;

[0047] One end of the jacket spray pipe inserted into the interior of the vertical cylinder is fixedly connected to the small end of the expansion pipe, and the large end of the expansion pipe faces the top of the cone-cap distribution plate I. The expansion pipe and the cone-cap distribution plate I are used in conjunction to form a liquid curtain by spraying ethylene glycol;

[0048] The fixing plate is located inside the jacket spray pipe, the fixing plate is fixedly connected to the outer wall of the spray pipe, and there is a gap between the fixing plate and the inner wall of the jacket spray pipe;

[0049] The fixing plate is used to support the jacket spray pipe. The reason why it is not directly fixedly connected to the inner wall of the jacket spray pipe is that when the temperature difference between the spray pipe and the ethylene glycol flowing in the jacket spray pipe is large, the thermal expansion and contraction of the pipeline due to the temperature difference is large, and a direct fixed connection may cause damage to the pipeline.

[0050] In the above-mentioned circulating spraying system of ethylene glycol, a cone is provided on the top of the conical cap distribution plate II, and the cone is inserted into the spray pipe from the orifice at the output end of the spray pipe; the design of the cone allows the ethylene glycol sprayed toward the spray pipe to form a better liquid curtain.

[0051] In the above-mentioned circulation spraying system of ethylene glycol, along the direction from the liquid seal tank 46 to the spraying pipe, the circulation pipe I is provided with valve s, filter I, pump I, valve n, plate heat exchanger I and valve b in sequence; pump I is used to transport the ethylene glycol in the liquid seal tank to the spraying pipe; plate heat exchanger I is used to cool the ethylene glycol;

[0052] Along the direction from the liquid seal tank to the spray pipe I, the circulation pipe II is provided with valve r, filter II, pump II, valve q, plate heat exchanger II, and valve a in sequence; pump II is used to transport the ethylene glycol in the liquid seal tank to the spray pipe; plate heat exchanger II is used to cool the ethylene glycol.

[0053] A circulating spray system for ethylene glycol as described above, wherein the circulating spray system for ethylene glycol further comprises a switching pipe I, a switching pipe II, a production pipe I and a production pipe II;

[0054] Assume that there is a connection point A between pump I and valve n on the circulation pipe I, and a connection point B on the circulation pipe I between valve n and plate heat exchanger I; Assume that there is a connection point C between pump II and valve q on the circulation pipe II, and a connection point D between valve q and plate heat exchanger II on the circulation pipe II; one end of the switching pipe I is connected to the connection point A, the other end of the switching pipe I is connected to the connection point D, and a valve o is provided on the switching pipe I; one end of the switching pipe II is connected to the connection point B, and the other end is connected to the connection point C; a valve p is provided on the switching pipe II;

[0055] Assume that there is a connection point E between the plate heat exchanger I and the valve b on the circulation pipe I, and there is a connection point F between the plate heat exchanger II and the valve a on the circulation pipe II; one end of the production pipe I is connected to the connection point E, and the other end is connected to the outside world; along the direction from the connection point E to the outside world, valves k and valves m are sequentially arranged on the production pipe I; the input end of the production pipe II is connected to the connection point F, and the output end of the production pipe II is connected to the production pipe I between the valves k and the valves m; a valve l is arranged on the production pipe II;

[0056] When there is too much ethylene glycol in the liquid seal tank (ethylene glycol vapor in the exhaust gas is captured and falls into the circulation system), the flow in the circulation system is kept stable by controlling valves k, valve l and valve m; the switching pipes I and II are designed to prevent the problem of failure to spray ethylene glycol due to partial pipeline damage.

[0057] A circulating spray system for ethylene glycol as described above, wherein the circulating spray system for ethylene glycol further comprises a circulating pipe III, a circulating pipe IV and a circulating pipe V;

[0058] Assume that there is a connection point G between valve r and filter II on circulation pipe II, and a connection point H between connection point F and valve a on circulation pipe II; one end of circulation pipe III is connected to connection point G, and the other end is connected to connection point H; a jacket heat exchanger is provided on circulation pipe III; the jacket heat exchanger is used to heat hexanediol; a valve u is provided between the jacket heat exchanger and connection point G on circulation pipe III, and a valve w is provided on circulation pipe III between the jacket heat exchanger and connection point H;

[0059] Assume that there is a connection point I between valve s and filter I on the circulation pipe I, and a connection point J between connection point E and valve b; one end of the circulation pipe IV is connected to the connection point I, and the other end is connected to between valve u of the circulation pipe II and the jacket heat exchanger; the circulation pipe IV is provided with a valve t; one end of the circulation pipe V is connected to the connection point J, and the other end is connected to between valve w on the circulation pipe III and the jacket heat exchanger; the circulation pipe V is provided with a valve x;

[0060] When online cleaning of circulation pipe I is required, the valve is controlled so that circulation pipe I, circulation pipe IV, part of circulation pipe III and circulation pipe V form an online cleaning circulation system, thereby realizing the cleaning of circulation pipe I, while circulation pipe II is still involved in ethylene glycol spraying; when online cleaning of circulation pipe II is required, the valve is controlled so that circulation pipe II and circulation pipe III form an online cleaning circulation system, thereby realizing the cleaning of circulation pipe II, while circulation pipe I is still involved in ethylene glycol spraying; as set as above, online cleaning of circulation pipes I and II can be realized.

[0061] A circulating spray system for ethylene glycol as described above, wherein the circulating spray system for ethylene glycol further comprises a buffer tank, a replenishing pipe and an overflow pipe;

[0062] Assume that there is a connection point K between valve w and the jacket heat exchanger on the circulation pipe III, a connection point L between valve k and valve m on the production pipe I, and a connection point M between valve m and the discharge port of the production pipe I on the production pipe I; one end of the feed pipe is connected to the connection point K, and the other end is connected to the connection point L; the buffer tank is arranged on the feed pipe; one end of the overflow pipe is connected to the buffer tank, and the other end is connected to the connection point M; the feed pipe is also provided with a valve v, and when the liquid in the buffer tank overflows, the valve v is closed to stop adding ethylene glycol;

[0063] During the process of online cleaning of circulation pipes I and II, ethylene glycol in the circulation pipe being sprayed can be introduced into the circulation pipe being cleaned online through the replenishing pipe, so that the circulation pipe being cleaned online can be further filled with ethylene glycol (when ethylene glycol overflows from the buffer tank 47 through the overflow pipe, it is filled).

[0064] In the above-mentioned circulating spraying system of ethylene glycol, the connection point N is located between the valve b and the connection point Q, the connection point Q is located between the connection point N and the connection point E; the connection point O is located between the connection point H and the connection point F; and the connection point P is located between the spray pipe and the connection point H.

[0065] A circulating spraying system for ethylene glycol as described above, wherein the circulating spraying system for ethylene glycol further comprises a flow meter I, a flow meter II, a valve i and a valve j;

[0066] Valve i and flowmeter I are arranged on circulation pipe I; flowmeter I is located between connection point Q and valve i, and valve i is located between connection point N and flowmeter I;

[0067] Valve j and flow meter II are arranged on circulation pipe II; flow meter II is located between valve j and connection point O, and valve j is located between connection point H and connection point O;

[0068] Flowmeter I and flowmeter II are respectively used to detect the spray flow of the spray pipe and the jacket spray pipe during cleaning, and valve i and valve j are respectively used to adjust the flow according to the corresponding flowmeter.

[0069] Beneficial effects:

[0070] (1) The present invention can control the cold ethylene glycol to cover the hot ethylene glycol and the condensable gas and entrained matter by controlling the valve, thereby achieving the purpose of online cleaning inside the spray pipe without reducing the spraying effect.

[0071] (2) The present invention can control the hot ethylene glycol to flow into the circulation pipe I and the circulation pipe II through the external pipe I, the external pipe II, the external pipe III and the external pipe IV, so as to achieve online cleaning of the inside of the spray pipe, the jacket spray pipe, the circulation pipe I and the circulation pipe II. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Figure 1 A schematic diagram of a glycol circulation spraying system in the prior art;

[0073] Figure 2 It is a schematic diagram of the circulation spraying system of ethylene glycol of the present invention;

[0074] Figure 3 It is a partial schematic diagram of the ethylene glycol circulation spraying system of the present invention;

[0075] Figure 4 It is a cross-sectional view of the jacketed spray pipe of the present invention after being sleeved on the spray pipe;

[0076] Figure 5 It is a schematic diagram of the cooperation between the cone-hat type distribution plate I and the cone-hat type distribution plate II of the present invention;

[0077] Among them, 1-spray pipe, 2-jacketed spray pipe, 3-external pipe I, 4-fixed plate, 5-cone-hat type distribution plate I, 6-cone-hat type distribution plate II, 7-vertebral body, 8-connecting plate I, 9-connecting plate II, 10-expanding pipe, 11-fixing ring, 12-vertical cylinder, 13-valve a, 14-valve b, 15-valve c, 16-valve d, 17-valve e, 18-valve f, 19-temperature gauge, 20-mixer, 21-valve g, 22-valve h, 23-valve i, 24-valve j, 25-flow meter I, 26-flow meter II, 27-valve k, 28-valve l, 29-valve m, 30-plate heat exchanger I, 31-plate heat exchanger II, 32-valve n, 33-valve o, 34-valve p, 35-valve q, 36-pump I, 37-pump II, 38-filter I, 39-filter II, 40-valve r, 41-valve s, 42-valve t, 43-valve u, 44-jacketed heat exchanger, 45-horizontal cylinder, 46-liquid seal tank, 47-buffer tank, 48-valve v, 49-valve w, 50-valve x, 51-valve y, 52-connection point A, 53-connection point B, 54-connection point C, 55-connection point D, 56-connection point E, 57-connection point F, 58-connection point G, 59-connection point H, 60-connection point I, 61-connection point J, 62-connection point K, 63-connection point L, 64 connection point M, 65-connection point N, 66-connection point O, 67-connection point P, 68-connection point Q, 69-connection point R. DETAILED DESCRIPTION

[0078] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0079] A glycol circulation spray system, such as Figures 2 to 5 As shown, it includes a spray pipe 1, a scraper condenser, a lower liquid pipe, a liquid seal tank 46, a circulation pipe I, a circulation pipe II, a jacketed spray pipe 2, a cone-shaped distribution plate I 5, an additional pipe I 3, an additional pipe II, an additional pipe III, an additional pipe IV, an additional pipe V, an atomizing nozzle, an additional pipe VI, an additional pipe VII, an additional pipe VIII, a connecting plate I 8, a connecting plate II 9, an expansion pipe 10, a fixing ring 11, a plurality of fixing plates 4, a switching pipe I, a switching pipe II, a production pipe I, a production pipe II, a circulation pipe III, a circulation pipe IV, a circulation pipe V, a buffer tank 47, a supplementary pipe and an overflow pipe;

[0080] The scraper condenser comprises a horizontal cylinder 45, a vertical cylinder 12 and a conical cap type distribution plate II 6;

[0081] A vacuum suction port is provided on the top of the vertical cylinder 12, and the vacuum suction port is used to connect to the vacuum system;

[0082] A discharge port is provided at the lower part of the horizontal cylinder 45; the discharge port is connected to the liquid seal tank 46 through a lower liquid pipe; the liquid seal tank 46 is used to receive and filter ethylene glycol;

[0083] like Figures 3 to 5 As shown, a cone is provided on the top of the cone-shaped distribution plate II 6, and the cone-shaped distribution plate II 6 is fixedly connected to the inner wall of the vertical cylinder 12 through the connecting plate II 9;

[0084] The cone-hat type distribution plate I 5 is located above the cone-hat type distribution plate II 6, and a through hole II is provided on the cone-hat type distribution plate I 5;

[0085] The output end of the spray pipe 1 is inserted into the vertical cylinder 12 and passes through the through hole II, and is fixedly connected to the through hole II, and the orifice of the output end of the spray pipe 1 faces the top of the cone-shaped cap distribution plate II 6, and the cone is inserted into the spray pipe 1 from the orifice of the output end of the spray pipe 1; the cone-shaped cap distribution plate II 6 is used to evenly spray the ethylene glycol sprayed from the spray pipe 1 in the vertical cylinder 12;

[0086] The jacket spray pipe 2 is sleeved on the spray pipe 1; one end of the jacket spray pipe 2 is sealed and connected to the spray pipe 1, and the other end is inserted into the interior of the vertical cylinder 12 and fixedly connected to the small end of the expansion pipe 10, and the large end of the expansion pipe 10 faces the top of the cone-cap distribution plate 15;

[0087] The fixing plate 4 is located inside the jacket spray pipe 2, the fixing plate 4 is fixedly connected to the outer wall of the spray pipe 1, and there is a gap between the fixing plate 4 and the inner wall of the jacket spray pipe 2;

[0088] The fixing ring 11 is sleeved on the jacket spray pipe 2 and fixedly connected to the jacket spray pipe 2; the fixing ring 11 is fixedly connected to the inner wall of the vertical cylinder 12 through the connecting plate I8;

[0089] The atomizing nozzle is located inside the vertical cylinder 12 and above the conical cap type distribution plate I 5; one end of the external tube V is inserted into the vertical cylinder 12 and connected to the atomizing nozzle, and the other end of the external tube V is used to introduce fresh ethylene glycol I; a valve y 51 is provided on the external tube V;

[0090] like Figure 2 , Figure 3 As shown, one end of the circulation pipe I and the circulation pipe II are respectively connected to the liquid seal groove 46, and the other end is respectively connected to the input end of the spray pipe 1;

[0091] Along the direction from the liquid seal groove 46 to the spray pipe 1, the circulation pipe I is provided with valve s 41, filter I 38, pump I 36, valve n 32, plate heat exchanger I 30, flow meter I 25, valve i 23, valve b 14 in sequence; pump I 36 is used to transport the ethylene glycol in the liquid seal groove 46 to the spray pipe 1; plate heat exchanger I 30 is used to cool the ethylene glycol;

[0092] Along the direction from the liquid seal groove 46 to the spray pipe I 1, the circulation pipe II is provided with valve r 40, filter II 39, pump II 37, valve q 35, plate heat exchanger II 31, flow meter II 26, valve j 24, valve a 13 in sequence; pump II 37 is used to transport the ethylene glycol in the liquid seal groove 46 to the spray pipe 1; plate heat exchanger II 31 is used to cool the ethylene glycol;

[0093] Assume that there is a connection point A 52 between pump I 36 and valve n 32 on the circulation pipe I, and a connection point B 53 between valve n 32 and plate heat exchanger I 30 on the circulation pipe I; assume that there is a connection point C 54 between pump II 37 and valve q 35 on the circulation pipe II, and a connection point D 55 between valve q 35 and plate heat exchanger II 31 on the circulation pipe II; one end of the switching pipe I is connected to the connection point A 52, the other end of the switching pipe I is connected to the connection point D 55, and the switching pipe I is provided with a valve o 33; one end of the switching pipe II is connected to the connection point B 53, and the other end is connected to the connection point C 54, and the switching pipe II is provided with a valve p 34;

[0094] Assume that there is a connection point E 56 between the plate heat exchanger I 30 and the valve b 14 on the circulation pipe I, and there is a connection point F 57 between the plate heat exchanger II 31 and the valve a 13 on the circulation pipe II; one end of the production pipe I is connected to the connection point E 56, and the other end is connected to the outside world; along the direction from the connection point E 56 to the outside world, valves k 27 and valves m 29 are sequentially arranged on the production pipe I; the input end of the production pipe II is connected to the connection point F 57, and the output end of the production pipe II is connected to the production pipe I between the valves k 27 and the valves m 29; a valve l 28 is arranged on the production pipe II;

[0095] Assume that there is a connection point G 58 between valve r 40 and filter II 39 on circulation pipe II, and a connection point H 59 between connection point F 57 and valve a 13 on circulation pipe II; one end of circulation pipe III is connected to connection point G 58, and the other end is connected to connection point H 59; jacket heat exchanger 44 is provided on circulation pipe III; jacket heat exchanger 44 is used to heat hexanediol; valve u 43 is provided on circulation pipe III between jacket heat exchanger 44 and connection point G 58, and valve w 49 is provided on circulation pipe III between jacket heat exchanger 44 and connection point H 59;

[0096] Assume that there is a connection point I 60 between valve s 41 and filter I 38 on the circulation pipe I, and a connection point J 61 between connection point E 56 and valve b14; one end of the circulation pipe IV is connected to the connection point I 60, and the other end is connected to between valve u43 and jacket heat exchanger 44 of the circulation pipe II; the circulation pipe IV is provided with a valve t 42; one end of the circulation pipe V is connected to the connection point J 61, and the other end is connected to between valve w 49 and jacket heat exchanger 44 on the circulation pipe III; the circulation pipe V is provided with a valve x 50;

[0097] Assume that there is a connection point O 66 between the spray pipe 1 and the plate heat exchanger II 31 on the circulation pipe II; one end of the external pipe II is connected to the connection point O 66, and the other end is connected to one end of the external pipe VI through a tee pipe; a valve f 18 is provided on the external pipe II;

[0098] Assume that there is a connection point P 67 between the spray pipe 1 and the plate heat exchanger II 31 on the circulation pipe II, and there is a connection point R 69 on the additional pipe I 3 between the valve d 16 and the spray pipe 1 on the additional pipe I; one end of the additional pipe III is connected to the connection point R 69, and the other end is connected to the connection point P 67, and a valve c 15 is provided on the additional pipe III; a valve a 13 is provided on the circulation pipe II between the connection point P 67 and the spray pipe 1;

[0099] A mixer 20 is provided on the external pipe VI, and the mixer 20 is used to mix the hot ethylene glycol at 170°C to 180°C and the fresh ethylene glycol II into the hot ethylene glycol at 120°C to 140°C; a thermometer 19 is provided on the mixer 20, and the thermometer 19 is used to detect the temperature inside the mixer 20;

[0100] The external pipe VII and the external pipe VIII are connected to the other end of the external pipe VI through a tee pipe; the external pipe VII is provided with a valve g 21, and the external pipe VIII is provided with a valve h 22; the end of the external pipe VII not connected to the external pipe VI is used to introduce hot ethylene glycol at 170° C. to 180° C., and the end of the external pipe VIII not connected to the external pipe VI is used to introduce fresh ethylene glycol II;

[0101] A connection point N 65 is provided on the circulation pipe I between the valve b 14 and the connection point Q 68; one end of the additional pipe I 3 is connected to the jacket spray pipe 2, and the other end is connected to the connection point N 65, and a valve d 16 is provided on the additional pipe I 3;

[0102] Assume that there is a connection point Q 68 between the spray pipe 1 and the plate heat exchanger I 30 on the circulation pipe I; one end of the external pipe IV is connected to the connection point Q 68, and the other end is connected to one end of the external pipe VI through a tee pipe; a valve e17 is provided on the external pipe IV;

[0103] The valve i 23 and the flow meter I 25 are arranged on the circulation pipe I; the flow meter I 25 is located between the connection point Q 68 and the valve i 23, and the valve i 23 is located between the connection point N 65 and the flow meter I 25;

[0104] The connection point Q 68 is located between the connection point N 65 and the connection point E 56;

[0105] The connection point O 66 is located between the connection point H 59 and the connection point F 57; the connection point P 67 is located between the spray pipe 1 and the connection point H 59;

[0106] Valve j 24 and flow meter II 26 are arranged on circulation pipe II; flow meter II 26 is located between valve j 24 and connection point O 66, and valve j 24 is located between connection point H 59 and connection point O 66;

[0107] Assume that there is a connection point K62 between the valve w49 and the jacket heat exchanger 44 on the circulation pipe III, a connection point L63 between the valve k27 and the valve m29 on the production pipe I, and a connection point M64 between the valve m29 and the discharge outlet of the production pipe I on the production pipe I; one end of the feed pipe is connected to the connection point K62, and the other end is connected to the connection point L63; the buffer tank 47 is arranged on the feed pipe; one end of the overflow pipe is connected to the buffer tank 47, and the other end is connected to the connection point M64; a valve v48 is also provided on the feed pipe.

[0108] The use process of the above device is as follows: Figure 2 As shown, in the polyester production process, the tail gas generated by the polycondensation reaction will be removed through the scraper condenser to remove the condensable gas and entrained materials therein, so that only the non-condensable gas enters the vacuum system through the vacuum suction port. During this process, with the long-term use of the scraper condenser, the small-volume substances are not easy to be removed and will adhere to the spray pipe 1, the jacket spray pipe 2 and the inner tube of the circulation pipe. At this time, the above-mentioned device is required to clean them;

[0109] Due to the existence of the additional pipes I 3, II, III and IV, both hot ethylene glycol and cold ethylene glycol can be introduced into the circulation pipes I and II of the present invention, so only some usage situations are illustrated below:

[0110] When the inner tube of the spray pipe 1 needs to be cleaned, first close valve r 40, valve t 42, valve u 43, then open valve d 16 and close valve b 14, let the cold ethylene glycol in the circulation pipe I enter the jacket spray pipe 2 and spray out from the large end of the expansion pipe, then open valve h 22 to pass fresh ethylene glycol II into the mixer 20, then open valve f 18, valve j24, valve a 13, pass fresh ethylene glycol II into the circulation pipe II and the spray pipe 1 and spray out from the output end of the spray pipe 1, then open valve g 21 The hot ethylene glycol at a temperature of 170°C to 180°C is introduced so that the temperature of the hot ethylene glycol in the mixer 20 gradually rises from a relatively low temperature to 120°C to 140°C, ensuring that the cold ethylene glycol can cover the hot ethylene glycol and the condensable gas and entrained matter. Then, the sprayed ethylene glycol, condensed gas and entrained matter pass through the discharge port of the horizontal cylinder 45 and enter the liquid seal tank 46, where they are filtered and then recycled. In this way, online cleaning of the inside of the spray pipe 1 and the circulation pipe II can be achieved without reducing the spraying effect.

[0111] When it is necessary to clean the inner tube of the jacket spray pipe 2, first ensure that the circulation pipe I has cold ethylene glycol circulating and spraying normally from the spray pipe 1 through the valve b 14, then close the valve r 40, valve t 42, valve u 43, valve a 13, and then open the valve h22 to pass fresh ethylene glycol II into the mixer 20, and then open the valve f 18, valve j 24, valve c 15, pass the fresh ethylene glycol II into the circulation pipe II and the jacket spray pipe 2 and spray it out from the large end of the expansion pipe, and then open the valve g 21 to pass the hot ethylene glycol with a temperature of 170℃~180℃ so that the temperature of the hot ethylene glycol in the mixer 20 gradually rises from a lower temperature to 120℃~140℃, and at the same time open the valve y 51, fresh ethylene glycol I is allowed to enter the vertical cylinder 12 for spraying, thereby covering the hot ethylene glycol, and then the sprayed ethylene glycol and condensed gas and entrained matter enter the liquid seal tank 46 after passing through the discharge port of the horizontal cylinder 45 and are filtered and then continuously recycled, so that the online cleaning of the jacket spray pipe 2 and the circulation pipe II can be achieved without reducing the spraying effect.

Claims

1. A circulation spray system for ethylene glycol, comprising a spray pipe (1), a scraper condenser, a downpipe, a liquid seal groove (46), a circulation pipe I and a circulation pipe II; the scraper condenser comprises a horizontal cylinder (45) and a vertical cylinder (12); the output end of the spray pipe (1) is inserted into the vertical cylinder (12); one end of the circulation pipe I and the circulation pipe II are respectively connected to the liquid seal groove (46), and the other end is respectively connected to the input end of the spray pipe (1); the circulation pipe I is provided with a valve s (41), a pump I (36) and a plate heat exchanger I (30); the circulation pipe II is provided with a valve r (40), a pump II (37) and a plate heat exchanger II (31); the valve s (41) is located between the plate heat exchanger I (30) and the liquid seal groove (46), and the valve r (40) is located between the plate heat exchanger II (31) and the liquid seal groove (46); the characteristic is that The ethylene glycol circulation spraying system further includes a jacket spraying pipe (2), an additional pipe I (3) and an additional pipe II; The jacketed spray pipe (2) is sleeved on the spray pipe (1); one end of the jacketed spray pipe (2) is sealedly connected to the spray pipe (1), and the other end is inserted into the interior of the vertical cylinder (12); Assume that a connection point N (65) is provided between the spray pipe (1) and the plate heat exchanger I (30) on the circulation pipe I; one end of the external pipe I (3) is connected to the jacket spray pipe (2), and the other end is connected to the connection point N (65); a valve b (14) is provided on the circulation pipe I between the connection point N (65) and the spray pipe (1); Assume that there is a connection point O (66) between the spray pipe (1) and the plate heat exchanger II (31) on the circulation pipe II; one end of the external pipe II is connected to the connection point O (66), and the other end is used to pass hot ethylene glycol above 120° C.; a valve f (18) is provided on the external pipe II.

2. The ethylene glycol circulation spraying system according to claim 1, characterized in that: A vacuum suction port is provided at the top of the vertical cylinder (12), and the vacuum suction port is used to be connected to a vacuum system; a discharge port is provided at the bottom of the horizontal cylinder (45), and the discharge port is connected to a liquid sealing tank (46) via a lower liquid pipe; the liquid sealing tank (46) is used to receive ethylene glycol and filter it.

3. The ethylene glycol circulation spraying system according to claim 2, characterized in that: The ethylene glycol circulation spraying system further includes a cone-shaped distribution plate I (5) and a cone-shaped distribution plate II (6); The cone-shaped distribution plate II (6) is located inside the vertical cylinder (12); the output end of the spray pipe (1) is inserted into the vertical cylinder (12), and the orifice of the output end of the spray pipe (1) faces the top of the cone-shaped distribution plate II (6); the cone-shaped distribution plate II (6) is used to evenly spray the ethylene glycol sprayed from the spray pipe (1) inside the vertical cylinder (12); The cone-shaped distribution plate I (5) is located above the cone-shaped distribution plate II (6); a through hole II is provided on the cone-shaped distribution plate I (5); the output end of the spray pipe (1) passes through the through hole II and is fixedly connected to the through hole II.

4. The ethylene glycol circulation spraying system according to claim 3, characterized in that: The ethylene glycol circulation spraying system also includes an additional pipe III, an additional pipe IV, an additional pipe V and an atomizing nozzle; Assume that a connection point P (67) is provided between the spray pipe (1) and the plate heat exchanger II (31) on the circulation pipe II; one end of the external pipe III is connected to the jacket spray pipe (2), and the other end is connected to the connection point P (67); a valve a (13) is provided on the circulation pipe II between the connection point P (67) and the spray pipe (1); Assume that a connection point Q (68) is provided between the spray pipe (1) and the plate heat exchanger I (30) on the circulation pipe I; one end of the external pipe IV is connected to the connection point Q (68), and the other end is used to pass hot ethylene glycol above 120° C.; a valve e (17) is provided on the external pipe IV; The external pipe I (3) is provided with a valve d (16), and the external pipe III is provided with a valve c (15); The atomizing nozzle is located inside the vertical cylinder (12) and above the conical cap type distribution plate I (5); one end of the external pipe V is inserted into the vertical cylinder (12) and connected to the atomizing nozzle, and the other end of the external pipe V is used to introduce fresh ethylene glycol I; a valve y (51) is provided on the external pipe V.

5. The ethylene glycol circulation spraying system according to claim 4, characterized in that: Assume that a connection point R (69) is provided on the external pipe I (3) between the valve d (16) and the spray pipe (1), one end of the external pipe III is connected to the connection point R (69), and the other end is connected to the connection point P (67).

6. The ethylene glycol circulation spraying system according to claim 5, characterized in that: The ethylene glycol circulation spray system also includes an additional pipe VI, an additional pipe VII and an additional pipe VIII; An end of the external pipe II not connected to the connection point O (66) and an end of the external pipe IV not connected to the connection point Q (68) are connected to one end of the external pipe VI via a tee, and the external pipe VII and the external pipe VIII are connected to the other end of the external pipe VI via a tee; a valve g (21) is provided on the external pipe VII, and a valve h (22) is provided on the external pipe VIII; the end of the external pipe VII not connected to the external pipe VI is used to introduce hot ethylene glycol at 170° C. to 180° C., and the end of the external pipe VIII not connected to the external pipe VI is used to introduce fresh ethylene glycol II; The external pipe VI is provided with a mixer (20), which is used to mix hot ethylene glycol at 170° C. to 180° C. and fresh ethylene glycol II into hot ethylene glycol at 120° C. to 140° C.; the mixer (20) is provided with a temperature gauge (19), which is used to detect the temperature inside the mixer (20).

7. The ethylene glycol circulation spraying system according to claim 6, characterized in that: The ethylene glycol circulation spraying system further comprises a connecting plate I (8), a connecting plate II (9), an expansion pipe (10), a fixing ring (11) and a plurality of fixing plates (4); The fixing ring (11) is sleeved on the jacket spray pipe (2) and is fixedly connected to the jacket spray pipe (2); the fixing ring (11) is fixedly connected to the inner wall of the vertical cylinder (12) via a connecting plate I (8); The cone-shaped distribution plate II (6) is fixedly connected to the inner wall of the vertical cylinder (12) via a connecting plate II (9); One end of the jacket spray pipe (2) inserted into the interior of the vertical cylinder (12) is fixedly connected to the small end of the expansion pipe (10), and the large end of the expansion pipe (10) faces the top of the cone-shaped distribution plate I (5); The fixing plate (4) is located inside the jacket spray pipe (2), the fixing plate (4) is fixedly connected to the outer wall of the spray pipe (1), and there is a gap between the fixing plate (4) and the inner wall of the jacket spray pipe (2).

8. The ethylene glycol circulation spraying system according to claim 7, characterized in that: A cone is provided on the top of the cone-hat type distribution plate II (6), and the cone is inserted into the spray pipe (1) from the orifice at the output end of the spray pipe (1).

9. The ethylene glycol circulation spraying system according to claim 8, characterized in that: Along the direction from the liquid seal groove 46 to the spray pipe (1), the circulation pipe I is provided with a valve s (41), a filter I (38), a pump I (36), a valve n (32), a plate heat exchanger I (30) and a valve b (14) in sequence; the pump I (36) is used to transport the ethylene glycol in the liquid seal groove (46) to the spray pipe (1); the plate heat exchanger I (30) is used to cool the ethylene glycol; Along the direction from the liquid seal groove (46) to the spray pipe I (1), the circulation pipe II is provided with a valve r (40), a filter II (39), a pump II (37), a valve q (35), a plate heat exchanger II (31), and a valve a (13) in sequence; the pump II (37) is used to transport the ethylene glycol in the liquid seal groove (46) to the spray pipe (1); and the plate heat exchanger II (31) is used to cool the ethylene glycol.

10. The ethylene glycol circulation spraying system according to claim 9, characterized in that: The circulation spraying system of ethylene glycol also includes a switching pipe I, a switching pipe II, a production pipe I and a production pipe II; Assume that there is a connection point A (52) between the pump I (36) and the valve n (32) on the circulation pipe I, and a connection point B (53) between the valve n (32) and the plate heat exchanger I (30) on the circulation pipe I; assume that there is a connection point C (54) between the pump II (37) and the valve q (35) on the circulation pipe II, and a connection point D (55) between the valve q (35) and the plate heat exchanger II (31) on the circulation pipe II; one end of the switching pipe I is connected to the connection point A (52), the other end of the switching pipe I is connected to the connection point D (55), and the switching pipe I is provided with a valve o (33); one end of the switching pipe II is connected to the connection point B (53), and the other end is connected to the connection point C (54); the switching pipe II is provided with a valve p (34); Assume that a connection point E (56) is provided on the circulation pipe I between the plate heat exchanger I (30) and the valve b (14), and a connection point F (57) is provided on the circulation pipe II between the plate heat exchanger II (31) and the valve a (13); one end of the production pipe I is connected to the connection point E (56), and the other end is connected to the outside world; along the direction from the connection point E (56) to the outside world, valves k (27) and valves m (29) are provided on the production pipe I in sequence; the input end of the production pipe II is connected to the connection point F (57), and the output end of the production pipe II is connected to the production pipe I between the valves k (27) and the valves m (29); and a valve l (28) is provided on the production pipe II.

11. The ethylene glycol circulation spraying system according to claim 10, characterized in that: The ethylene glycol circulation spray system also includes a circulation pipe III, a circulation pipe IV and a circulation pipe V; Assume that a connection point G (58) is provided on the circulation pipe II between the valve r (40) and the filter II (39), and a connection point H (59) is provided on the circulation pipe II between the connection point F (57) and the valve a (13); one end of the circulation pipe III is connected to the connection point G (58), and the other end is connected to the connection point H (59); a jacket heat exchanger (44) is provided on the circulation pipe III; the jacket heat exchanger (44) is used to heat hexanediol; a valve u (43) is provided on the circulation pipe III between the jacket heat exchanger (44) and the connection point G (58), and a valve w (49) is provided on the circulation pipe III between the jacket heat exchanger (44) and the connection point H (59); Assume that there is a connection point I (60) between the valve s (41) and the filter I (38) on the circulation pipe I, and a connection point J (61) between the connection point E (56) and the valve b (14); one end of the circulation pipe IV is connected to the connection point I (60), and the other end is connected to between the valve u (43) and the jacket heat exchanger (44) of the circulation pipe II; the circulation pipe IV is provided with a valve t (42); one end of the circulation pipe V is connected to the connection point J (61), and the other end is connected to between the valve w (49) and the jacket heat exchanger (44) on the circulation pipe III; and the circulation pipe V is provided with a valve x (50).

12. The ethylene glycol circulation spraying system according to claim 11, characterized in that: The ethylene glycol circulation spraying system also includes a buffer tank (47), a replenishing pipe and an overflow pipe; Assume that a connection point K (62) is provided on the circulation pipe III between the valve w (49) and the jacket heat exchanger (44), a connection point L (63) is provided on the production pipe I between the valve k (27) and the valve m (29), and a connection point M (64) is provided on the production pipe I between the valve m (29) and the discharge port of the production pipe I; one end of the feed pipe is connected to the connection point K (62), and the other end is connected to the connection point L (63); the buffer tank (47) is provided on the feed pipe; one end of the overflow pipe is connected to the buffer tank (47), and the other end is connected to the connection point M (64).

13. The ethylene glycol circulation spraying system according to claim 12, characterized in that: The connection point N (65) is located between the valve b (14) and the connection point Q (68), and the connection point Q (68) is located between the connection point N (65) and the connection point E (56); the connection point O (66) is located between the connection point H (59) and the connection point F (57); and the connection point P (67) is located between the spray pipe (1) and the connection point H (59).

14. The ethylene glycol circulation spraying system according to claim 13, characterized in that: The ethylene glycol circulation spraying system further includes a flow meter I (25), a flow meter II (26), a valve i (23) and a valve j (24); The valve i (23) and the flow meter I (25) are arranged on the circulation pipe I; the flow meter I (25) is located between the connection point Q (68) and the valve i (23), and the valve i (23) is located between the connection point N (65) and the flow meter I (25); The valve j (24) and the flow meter II (26) are arranged on the circulation pipe II; the flow meter II (26) is located between the valve j (24) and the connection point O (66), and the valve j (24) is located between the connection point H (59) and the connection point O (66).

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