CN211782097U

CN211782097U - Novel shell and tube evaporator structure

Info

Publication number: CN211782097U
Application number: CN201922220311.XU
Authority: CN
Inventors: 刘志福; 邓军琦; 虞先晓
Original assignee: Ningbo Longhui Electromechanical Engineering Co ltd
Current assignee: Ningbo Longhui Electromechanical Engineering Co ltd
Priority date: 2019-12-11
Filing date: 2019-12-11
Publication date: 2020-10-27
Anticipated expiration: 2029-12-11

Abstract

The utility model relates to a novel shell and tube evaporator structure, include: a cylinder body, wherein a heat exchange tube is arranged in the cylinder body; the end cover assembly comprises an end cover and a liquid inlet pipe which is arranged on the end cover and used for conveying a refrigerant to the heat exchange pipe, the end cover is connected to the first end of the cylinder body, a liquid phase buffer cavity communicated with the heat exchange pipe is formed between the end cover and the cylinder body, and a plurality of capillary tubes used for guiding the refrigerant to a liquid inlet of the corresponding heat exchange pipe are arranged in the liquid inlet pipe in a matching mode; the liquid outlet of the capillary tube faces the liquid inlet of the heat exchange tube, and a gap for the refrigerant in the heat exchange tube to flow into the liquid phase buffer cavity is reserved between the liquid inlet of the capillary tube and the liquid inlet of the heat exchange tube; the end cover assembly also comprises a liquid return pipe communicated with the bottom of the liquid phase buffer cavity, and the liquid return pipe is positioned below the refrigerant liquid inlet pipe. The evaporator can not only enable the refrigerant to be uniformly distributed in the heat exchange tube in the refrigeration process, but also be beneficial to the liquid return of the condensing agent and the smooth oil return of lubricating oil in the heating process.

Description

Novel shell and tube evaporator structure

Technical Field

The utility model relates to an evaporimeter technical field especially relates to a novel shell and tube evaporimeter structure.

Background

In the field of air conditioning refrigeration, an evaporator is an indispensable key component. At present, in a chiller system, the most adopted evaporator form is a dry evaporator, the dry evaporator is a spaced heat exchanger using a wall surface of a tube bundle enclosed in a shell as a heat transfer surface, and the evaporator is a heat exchanger performing circulating cooling through a cold medium, and is widely applied in various fields, especially a shell-and-tube evaporator, because of its small volume, high heat transfer speed and high thermal efficiency, the shell-and-tube evaporator is more and more approved by users.

Because the refrigerant entering the heat exchange tube is mostly a mixture of refrigerant gas and refrigerant liquid (namely refrigerant gas-liquid mixture), the existing dry-type shell-tube U-shaped tube evaporator has double flow paths, the number of the branches is large, the flow path is short, wherein the refrigerant liquid is throttled and then the gas-liquid mixed refrigerant can not be effectively distributed to each flow path when entering the evaporator, the gas entering the heat exchange tube of the upper flow path is large, the liquid is small, the heat exchange efficiency is poor, the heat exchange efficiency of the whole heat exchanger is reduced, and meanwhile, the fault that the low pressure is too low during refrigeration and the high pressure is too high during heating is shown. Although some designs of conventional shell and tube evaporator structures have refrigeration liquid separating pore plates, the condition of uneven liquid separation from top to bottom still can occur, the refrigerant can play a certain flow equalizing effect through the flow equalizing plate, but after passing through the flow equalizing plate, the refrigerant is mixed in a gas-liquid mixing cavity and then enters the heat exchange tube. In the process, the liquid refrigerant can be deposited to a certain degree, and the liquid refrigerant is more in the refrigerant entering the lower-layer heat exchange tube.

In order to solve the technical problem, the chinese utility model patent with the application number CN201520507040.5 (No. CN204943982U) discloses a refrigerant inlet distributor of a dry evaporator, which is provided with a liquid distribution pipe in one-to-one correspondence with the heat exchange copper pipe at the refrigerant inlet end of the heat exchange copper pipe, and the liquid distribution pipe is in a diffusion shape with a small inlet end opening and a large outlet end opening, so that the refrigerant can be uniformly distributed to enter the heat exchange copper pipe, thereby ensuring uniform distribution of the refrigerant and improving the heat exchange efficiency. Further, a similar disclosure is made in the chinese utility model patent "dry shell-and-tube U-tube evaporator" with the application number CN201020220870.7 (publication number CN 201724594U).

Although the above-mentioned patent has solved the uneven problem of refrigerator refrigerant liquid separation through arranging liquid distribution pipe (capillary), but still there is certain not enough, liquid outlet end and the heat transfer copper pipe of liquid distribution pipe in the above-mentioned patent adopt the welding or expand tightly cup joint the mode and connect, and the diameter of liquid distribution pipe is less, in the heating process, the liquid refrigerant fluid resistance of the high pressure liquid after the condensation is great, it is inconvenient to return the liquid, on the other hand also does not do benefit to the oil return process of the lubricating oil of evaporimeter operation in-process compressor, therefore, how to provide one kind can make and make refrigerant evenly distributed to the heat transfer copper pipe in can also do benefit to the refrigerant return the liquid and the smooth shell and tube evaporator of oil return become the technical problem that this technical field personnel need to solve urgently.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem to prior art's current situation, provide one kind can make refrigerant evenly distributed can do benefit to the condensing agent again and return the novel shell and tube evaporator structure of liquid and the smooth oil return of lubricating oil in the heating process again to the heat exchange tube in the refrigeration process.

The utility model provides a technical scheme that above-mentioned technical problem adopted does: a novel shell and tube evaporator structure comprising:

a cylinder body, wherein a heat exchange tube is arranged in the cylinder body;

the end cover assembly comprises an end cover and a liquid inlet pipe which is arranged on the end cover and used for conveying a refrigerant to the heat exchange pipe, the end cover is connected to the first end of the cylinder body, a liquid phase buffer cavity communicated with the heat exchange pipe is formed between the end cover and the cylinder body, and a plurality of capillary tubes used for guiding the refrigerant to a liquid inlet of the corresponding heat exchange pipe are arranged in the liquid inlet pipe in a matching mode;

the liquid outlet of the capillary tube faces the liquid inlet of the heat exchange tube, and a gap for a refrigerant in the heat exchange tube to flow into the liquid phase buffer cavity is reserved between the liquid inlet of the capillary tube and the liquid inlet of the heat exchange tube;

the end cover assembly also comprises a liquid return pipe communicated with the bottom of the liquid phase buffer cavity, and the liquid return pipe is positioned below the refrigerant liquid inlet pipe.

In order to ensure the uniform distribution effect of the refrigerant in the refrigeration process, the number of the capillary tubes is the same as that of the heat exchange tubes, and the capillary tubes and the heat exchange tubes are in one-to-one correspondence.

Alternatively, the heat exchange tubes are divided into a plurality of groups, and each capillary tube corresponds to one group of heat exchange tubes. Namely, the pipe orifice of one capillary corresponds to the liquid inlet of one group of heat exchange pipes, so that the pipe diameter of the capillary is relatively larger, and the fluid resistance is reduced.

In order to enable the pipe orifice of the liquid inlet pipe to be arranged adjacent to each heat exchange pipe, reduce the length of the capillary pipe as much as possible and reduce the fluid resistance of the refrigerant in the capillary pipe, two liquid phase buffer cavities are arranged, correspondingly, two liquid inlet pipes are arranged on the end cover in parallel and are respectively and correspondingly communicated with the two liquid phase buffer cavities; similarly, in order to facilitate the liquid return and the oil return speed of the refrigerant, the number of the liquid return pipes is two, and the two liquid return pipes are arranged on the end cover in parallel and are respectively communicated with the two liquid-phase buffer cavities correspondingly. Of course, the evaporator can also be designed into a single system (only one liquid phase buffer cavity) or other multi-system (a plurality of isolated liquid phase buffer cavities) structure according to actual needs.

In the refrigeration process of the evaporator, lubricating oil circulating along with a refrigerant can be retained at a gas phase end (a refrigerant gas outlet position) as soon as possible, in order to enable the lubricating oil retained at the gas phase end to return oil, a gas phase buffer cavity is further formed between the end cover and the barrel body and is isolated from the liquid phase buffer cavity, a gas pipe communicated with the gas phase buffer cavity is further connected to the end cover, an injection pipe is further arranged in the gas pipe in a matched mode, the first end of the injection pipe is connected to the gas pipe, and the second pipe of the injection pipe extends to the bottom of the gas phase buffer cavity. Because the second pipe of the injection pipe extends to the bottom of the gas-phase buffer cavity, the lubricating oil retained in the gas-phase buffer cavity is sucked into the gas pipe and circulates to the compressor along with the refrigerant under the drive of high flow velocity and gas pressure.

In order to improve the oil return rate of lubricating oil at the gas phase end of the evaporator, two gas phase buffer cavities are provided, correspondingly, two gas pipes are provided, and the two gas pipes are arranged on the end cover in parallel in the horizontal direction and are respectively communicated with the two gas phase buffer cavities correspondingly; the number of the injection pipes is two, and the two injection pipes correspond to the two air pipes respectively.

In order to conveniently connect the end cover assembly to the cylinder, a flange is arranged at the first end of the cylinder, and the end cover is connected to the flange of the cylinder through bolts.

In order to improve the heat exchange efficiency, the heat exchange tube is a U-shaped tube, a first port of the U-shaped tube corresponds to a port of the liquid inlet tube, and a second port of the U-shaped tube corresponds to a port of the air tube.

In order to facilitate the connection of the evaporator and a conveying pipe for conveying secondary refrigerant (water), the upper part of the side wall of the cylinder body is also provided with a water inlet and a water outlet, and the water inlet and the water outlet are respectively positioned at two ends of the cylinder body.

In order to improve the heat exchange effect of the evaporator, the second end of the cylinder is provided with a seal head, baffle plates are sequentially arranged in the cylinder at intervals along the direction from the first end to the second end, and the two adjacent baffle plates are arranged in a staggered manner in the up-down direction.

Compared with the prior art, the utility model has the advantages that: the utility model provides a novel shell and tube evaporator structure has improved the liquid pipe tip of current evaporimeter, with liquid pipe end design for being arranged in the refrigeration in-process make things convenient for the feed liquor pipe of refrigerant feed liquor and make things convenient for the liquid return pipe of high pressure refrigerant after the condensation in-process to carry out the liquid return, when refrigerating, the refrigerant divides liquid to the heat exchange tube that corresponds in through the capillary through the feed liquor pipe waiting, realized refrigeration and divided the even purpose of liquid, on the other hand, in the heating process, the lubricating oil in the heat exchange tube and the inlet of the liquid refrigerant accessible capillary of high pressure after the condensation with in the gap gets into the liquid phase cushion chamber between the inlet of heat exchange tube, then return to the compressor in the liquid pipe fast through connecting in liquid phase cushion chamber bottom, and in needn't flow into the feed liquor pipe through the capillary, realize the purpose of returning liquid oil.

Drawings

Fig. 1 is a schematic perspective view of an embodiment of the present invention;

fig. 2 is a front view of an embodiment of the present invention;

fig. 3 is a side view (left side) of an embodiment of the present invention;

fig. 4 is a schematic structural diagram (refrigeration process) of an embodiment of the present invention;

fig. 5 is a schematic structural diagram (heating process) of an embodiment of the present invention;

fig. 6 is a schematic structural view of the inner side of the end cap assembly according to the embodiment of the present invention;

fig. 7 is a schematic perspective view of an end cap assembly according to an embodiment of the present invention;

fig. 8 is a cross-sectional view taken at a-a in fig. 3.

Detailed Description

The present invention will be described in further detail with reference to the following embodiments.

Referring to fig. 1 to 8, a novel shell and tube evaporator structure comprises a cylinder 10, a plurality of heat exchange tubes 40, a head 15, baffle plates and an end cover assembly 20, wherein the cylinder 10 is of a structure with two open ends, the heat exchange tubes 40 are specifically a plurality of heat exchange copper tubes arranged in the cylinder 10 and are arranged in a U shape in the cylinder 10, namely, a double tube pass, the end cover assembly 20 is arranged at a first end of the cylinder 10, the head 15 is arranged at a second end of the cylinder 10, the baffle plates 16 are arranged in the cylinder 10 and are sequentially arranged from the first end to the second end at intervals, and two adjacent baffle plates 16 are arranged in a staggered manner in the up-down direction.

Referring to fig. 2, a water inlet 13 and a water outlet 14 are further formed in the upper portion of the side wall of the cylinder 10, and the water inlet 13 and the water outlet 14 are respectively located at two ends of the cylinder 10, wherein secondary refrigerant (water) of the air conditioning unit can enter the shell pass of the evaporator through the water inlet 13, and flows out of the water outlet 14 after exchanging heat with the heat exchange tubes 40 in the cylinder 10, and the secondary refrigerant (water) is circulated to exchange heat in sequence.

Referring to fig. 6 to 8, the end cap assembly 20 includes an end cap 21, a liquid inlet pipe 22, a liquid return pipe 24, a capillary 23, a gas pipe 25, and an injection pipe 26, wherein the end cap 21 is connected to the flange 11 at the first end of the cylinder 10 by bolts 12, a gas phase buffer cavity 32 and a liquid phase buffer cavity 31 are formed between the end cap 21 and the cylinder 10 and are isolated from each other, and the gas phase buffer cavity 32 is located below the liquid phase buffer cavity 31. The liquid inlet pipe 22, the liquid return pipe 24 and the gas pipe 25 are all connected to the end cover 21, the liquid inlet pipe 22 and the liquid return pipe 24 are all communicated with the liquid phase buffer cavity 31, and the gas pipe 25 is connected with the gas phase buffer cavity 32. Two ports of the heat exchange tube 40 provided with the U shape are respectively communicated with the gas phase buffer chamber 32 and the liquid phase buffer chamber 31.

With continued reference to fig. 6-8, the liquid inlet tube 22 is used for conveying a refrigerant into the heat exchange tube 40, in order to enable the refrigerant to enter the heat exchange tube 40 more uniformly during a refrigeration process, a plurality of capillary tubes 23 are provided in the liquid inlet tube 22 for guiding the refrigerant into liquid inlets of the corresponding heat exchange tubes 40, specifically, liquid outlets of the capillary tubes 23 face liquid inlets of the heat exchange tubes 40, and a gap 200 is left between a liquid inlet of the capillary tube 23 and a liquid inlet of the heat exchange tube 40 for the refrigerant in the heat exchange tube 40 to flow into the liquid-phase buffer cavity 31, wherein the gap 200 can be formed by designing sizes of tube mouths of the capillary tubes 23 and the heat exchange tubes 40 (for example, designing a tube mouth diameter of the capillary tube 23 to be smaller than a tube mouth diameter of the heat exchange tube 40, and extending the capillary tube 23 into the heat exchange tube 40), or by adjusting an axial gap between a tube mouth of the capillary tube 23 and a tube mouth of The ports are spaced a distance apart) so that the refrigerant in the heat exchange tube 40 in a high pressure liquid state can be easily introduced into the liquid-phase buffer chamber 31 during the heating process.

In order to secure the effect of uniform distribution of refrigerant during the refrigeration process, the number of the capillary tubes 23 is the same as that of the heat exchange tubes 40, and corresponds one to one with each other. Of course, it is conceivable that the heat exchange tubes 40 are divided into a plurality of groups, and each capillary tube 23 corresponds to one group of heat exchange tubes 40, that is, the tube opening of one capillary tube 23 corresponds to the liquid inlet of one group of heat exchange tubes 40, so that the tube diameter of the capillary tube 23 is relatively large, and the fluid resistance is reduced.

Referring to fig. 8, a liquid return pipe 24 is connected to the end cover 21 and is located below the liquid inlet pipe 22, and the liquid return pipe 24 is communicated with the bottom of the liquid phase buffer chamber 31. In the refrigeration process, the refrigerant can enter each heat exchange tube 40 in sequence through the liquid inlet tube 22 and the capillary tube 23, so that the uniformity of liquid separation is ensured, and in the heating process, the refrigerant in the heat exchange tubes 40 can enter the liquid phase buffer cavity 31 from a gap flow channel formed between the liquid inlet of the capillary tube 23 and the liquid inlet of the heat exchange tubes 40 and then flows out through the liquid return tube 24, so that the fluid resistance is reduced, and the liquid return speed of the refrigerant is ensured.

On the other hand, the arrangement of the liquid return pipe 24 also facilitates the oil return of the lubricating oil retained at the liquid end of the evaporator in the heating process, wherein the oil return refers to the recovery of the lubricating oil of the compressor, and the lubricating oil can be mutually dissolved with the refrigerant, so that when the refrigerant flows out of the compressor, a part of the lubricating oil can be brought out, and thus the lubricating oil lost by the compressor can be taken back to the suction cavity of the compressor as far as possible in the design. The less the lubricating oil is stored in the shell-and-tube evaporator, the better, if the lubricating oil is stored in the shell-and-tube evaporator, the heat transfer area for refrigeration evaporation (or heating condensation) originally can be occupied, and the performance of the unit is influenced. More importantly, the normal operation of the compressor is influenced, and the lack of lubricating oil in the compressor can cause poor lubrication of the compressor and improper cooling of the compressor. In this embodiment, in the heating process, the lubricating oil carried by the refrigerant can flow into the liquid-phase buffer cavity 31 quickly from the gap flow channel formed between the liquid inlet of the capillary tube 23 and the liquid inlet of the heat exchange tube 40, and then flows out through the liquid return tube 24 and returns to the compressor, so as to ensure normal lubrication of the compressor, thereby improving the energy efficiency of the air conditioning unit, prolonging the service life of the compressor, and achieving the purpose of energy saving.

In order to dispose the pipe mouth of the liquid inlet pipe 22 adjacent to each heat exchange pipe 40, reduce the length of the capillary 23 as much as possible, and reduce the fluid resistance of the refrigerant in the capillary 23, the evaporator in this embodiment is designed as a dual-system structure, that is, the liquid-phase buffer cavity 31 is designed as two independent cavity structures, correspondingly, the gas-phase buffer cavity 32 is also designed as two independent cavity structures, further, there are two liquid inlet pipes 22, the two liquid inlet pipes 22 are juxtaposed on the end cover 21 in the horizontal direction, and the two liquid inlet pipes 22 are respectively communicated with the two liquid-phase buffer cavities 31. Similarly, there are two liquid return pipes 24, the two liquid return pipes 24 are horizontally arranged in parallel on the end cover 21, and the two liquid return pipes 24 are also respectively communicated with the two liquid phase buffer cavities 31. The number of the air pipes 25 is two, the two air pipes 25 are arranged on the end cover 21 in parallel in the horizontal direction, the two air pipes 25 are respectively communicated with the two gas-phase buffer cavities 32 correspondingly, and the number of the injection pipes 26 is two and is respectively corresponding to the two air pipes 25.

With reference to fig. 6 to 8, in the refrigeration process of the evaporator, the lubricant circulating with the refrigerant is also retained at the gas phase end (refrigerant gas outlet position), and in order to enable the lubricant retained at the gas phase end to return as soon as possible, an ejector pipe 26 is further provided in the gas pipe 25, wherein a first end of the ejector pipe 26 is connected to the gas pipe 25, and a second pipe of the ejector pipe 26 extends to the bottom of the gas phase buffer chamber 32. Because the second pipe of the injection pipe 26 extends to the bottom of the gas-phase buffer cavity 32, the lubricating oil retained in the gas-phase buffer cavity 32 is sucked into the gas pipe 25 and circulates to the compressor along with the refrigerant under the driving of high flow rate gas pressure.

The novel shell and tube evaporator structure in the embodiment works in the processes of refrigeration and heating:

the refrigeration cycle process: the external low-pressure liquid refrigerant enters the liquid inlet pipe 22, then is uniformly distributed into each heat exchange pipe 40 through each capillary tube 23 arranged in the liquid inlet pipe 22, and fully exchanges heat with secondary refrigerant (water) entering the shell side of the evaporator to cool the water, the refrigerant is vaporized in the heat exchange pipes 40 to form low-pressure gaseous refrigerant, and then the low-pressure gaseous refrigerant is output through the gas-phase buffer cavity 32 and the gas pipe 25 in sequence and returns to the compressor, meanwhile, lubricating oil remaining in the gas-phase buffer cavity 32 is sucked into the gas pipe 25 under the action of the injection pipe 26 and then circulates to the compressor along with the refrigerant, and details are shown in fig. 4 and 8.

A heating cycle process: an external high-pressure gas refrigerant enters the heat exchange tube 40 through the gas tube 25, and fully exchanges heat with water entering the shell side of the evaporator to heat the water, the high-pressure gas refrigerant is condensed and liquefied in the heat exchange tube 40 to form a high-pressure liquid refrigerant, the high-pressure liquid refrigerant and lubricating oil carried by the high-pressure liquid refrigerant can enter the liquid-phase buffer cavity 31 from a gap flow channel formed between a liquid inlet of the capillary tube 23 and a liquid inlet of the heat exchange tube 40, and then flow out through the liquid return tube 24, and finally circulate to the compressor, which is detailed in fig. 5 and 8.

Claims

1. A novel shell and tube evaporator structure comprising:

a cylinder (10) in which a heat exchange tube (40) is provided;

the end cover assembly (20) comprises an end cover (21) and a liquid inlet pipe (22) which is arranged on the end cover (21) and used for conveying a refrigerant into the heat exchange pipe (40), the end cover (21) is connected to the first end of the cylinder body (10) and forms a liquid phase buffer cavity (31) communicated with the heat exchange pipe (40) with the cylinder body (10), and a plurality of capillary tubes (23) used for guiding the refrigerant to a liquid inlet of the corresponding heat exchange pipe (40) are arranged in the liquid inlet pipe (22) in a matching mode;

the method is characterized in that: the liquid outlet of the capillary tube (23) faces the liquid inlet of the heat exchange tube (40), and a gap (200) for a refrigerant in the heat exchange tube (40) to flow into the liquid phase buffer cavity (31) is reserved between the liquid inlet of the capillary tube (23) and the liquid inlet of the heat exchange tube (40);

the end cover assembly (20) further comprises a liquid return pipe (24) communicated with the bottom of the liquid phase buffer cavity (31), and the liquid return pipe (24) is positioned below the refrigerant liquid inlet pipe (22).

2. The novel shell and tube evaporator structure of claim 1, wherein: the number of the capillaries (23) is the same as that of the heat exchange tubes (40), and the capillaries correspond to the heat exchange tubes one to one.

3. The novel shell and tube evaporator structure of claim 1, wherein: the heat exchange tubes (40) are divided into a plurality of groups, and each capillary tube (23) corresponds to one group of heat exchange tubes (40).

4. The novel shell and tube evaporator structure of claim 1, wherein: the number of the liquid phase buffer cavities (31) is two, correspondingly, the number of the liquid inlet pipes (22) is two, and the two liquid inlet pipes (22) are arranged on the end cover (21) in parallel and are respectively and correspondingly communicated with the two liquid phase buffer cavities (31);

the number of the liquid return pipes (24) is two, and the two liquid return pipes (24) are arranged on the end cover (21) in parallel and are respectively communicated with the two liquid phase buffer cavities (31) correspondingly.

5. The novel shell and tube evaporator structure as set forth in any one of claims 1-4, wherein: a gas phase buffer cavity (32) is further formed between the end cover (21) and the barrel body (10), the gas phase buffer cavity (32) is isolated from the liquid phase buffer cavity (31), a gas pipe (25) communicated with the gas phase buffer cavity (32) is further connected to the end cover (21), an injection pipe (26) is further arranged in the gas pipe (25) in a matched mode, the first end of the injection pipe (26) is connected to the gas pipe (25), and the second pipe of the injection pipe (26) extends to the bottom of the gas phase buffer cavity (32).

6. The novel shell and tube evaporator structure of claim 5, wherein: the number of the gas phase buffer cavities (32) is two, correspondingly, the number of the gas pipes (25) is two, and the two gas pipes (25) are arranged on the end cover (21) in parallel and are respectively correspondingly communicated with the two gas phase buffer cavities (32);

the number of the injection pipes (26) is two, and the two injection pipes correspond to the two air pipes (25) respectively.

7. The novel shell and tube evaporator structure of claim 1, wherein: the first end of barrel (10) is equipped with flange (11), end cover (21) pass through bolt (12) and connect on flange (11) of barrel (10).

8. The novel shell and tube evaporator structure of claim 5, wherein: the heat exchange tube (40) is a U-shaped tube, a first port of the U-shaped tube corresponds to a port of the liquid inlet tube (22), and a second port of the U-shaped tube corresponds to a port of the air tube.

9. The novel shell and tube evaporator structure of claim 5, wherein: the upper portion of the lateral wall of barrel (10) still is equipped with water inlet (13) and delivery port (14), water inlet (13) and delivery port (14) are located the both ends of barrel (10) respectively.

10. The novel shell and tube evaporator structure of claim 5, wherein: the second end of barrel (10) is equipped with head (15), barrel (10) are interior to be equipped with baffling board (16) along first end to the direction of second end interval in proper order, and staggered arrangement about the top down between two adjacent baffling board (16).