CN117298638A

CN117298638A - Low-pressure forming retainer and forming method thereof

Info

Publication number: CN117298638A
Application number: CN202311272960.9A
Authority: CN
Inventors: 沈小峰
Original assignee: Nantong Jinhai Anticorrosion Co ltd
Current assignee: Nantong Jinhai Anticorrosion Co ltd
Priority date: 2023-09-28
Filing date: 2023-09-28
Publication date: 2023-12-29

Abstract

The invention discloses a low-pressure forming retainer and a forming method thereof, comprising a retainer body, wherein a plurality of pipe holes for a graphite pipe to pass through and bolt holes for fixedly connecting with a heater are formed in the retainer body, the retainer body comprises an upper wrapping layer, a supporting layer and a lower wrapping layer which are sequentially connected in a stacked manner, the supporting layer is provided with a plurality of groups, and phenolic resin is wrapped in the upper wrapping layer, the supporting layer and the lower wrapping layer. The low-pressure forming retainer and the forming method thereof have reasonable structure, and the requirement on a press is reduced under the condition of meeting the strength of the retainer.

Description

Low-pressure forming retainer and forming method thereof

Technical Field

The invention relates to the technical field of flash evaporation devices, in particular to a low-pressure forming retainer and a forming method thereof.

Background

The retainer is commonly called a pattern plate and is fixedly arranged in a heater of the flash evaporation device and used for providing a mounting bracket for graphite tubes in the heater, steam flows through the graphite tubes in the heater and is used for heating dilute sulfuric acid flowing through the graphite tubes so as to evaporate water of the dilute sulfuric acid, and the purpose of concentrating the dilute sulfuric acid is achieved.

The diameter of the traditional retainer is 1.5 m, and the retainer of 1.5 m requires 1800 tons of presses (100 kg/square meter) when being manufactured.

Because the inner diameter main stream of the heater of the current customer is changed to 1.8-2.5 m, a 5000-ton press is needed to meet the pressing requirement, and because the product demand is not high, the investment cost of the 5000-ton press is excessive.

Accordingly, there is a need for improvements in the prior art cage structures and methods of forming the same.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide a low-pressure forming retainer and a forming method thereof, which can reduce the requirement on a press under the condition of meeting the strength of the retainer.

In order to achieve the technical effects, the technical scheme of the invention is as follows: the utility model provides a low pressure shaping holder, includes the holder body, be provided with a plurality of tube hole that supplies the graphite pipe to pass and be used for with heater fixed connection's bolt hole on the holder body, the holder body is including last parcel layer, supporting layer and the lower parcel layer of range upon range of connection in proper order, at least one deck is provided with reinforcing material in going up parcel layer, supporting layer and the lower parcel layer, the supporting layer is provided with a plurality of groups, it is provided with high temperature curing material to go up parcel layer, supporting layer and the equal parcel of lower parcel layer.

The preferable technical scheme is that the supporting layer comprises a base material layer and a reinforcing layer which are connected in a laminated mode, wherein the base material layer is a short fiber layer, and the short fiber layer comprises a glass fiber felt layer.

The preferable technical scheme is that the reinforcing layer is a long fiber layer, and the long fiber layer comprises a first glass fiber cloth layer.

The preferable technical scheme is that the reinforcing layer is a long fiber layer, and the long fiber layer comprises a glass fiber winding yarn layer.

The preferable technical scheme is that the reinforcing layer is a first glass fiber cloth layer and a glass fiber winding yarn layer, and the glass fiber felt layer, the first glass fiber cloth layer and the glass fiber winding yarn layer are sequentially connected in a lamination mode or the glass fiber felt layer, the glass fiber winding yarn layer and the first glass fiber cloth layer are sequentially connected in a lamination mode.

The preferable technical scheme is that the glass fiber yarns of the glass fiber winding yarn layer are arranged on the periphery of the pipe hole.

The preferable technical scheme is that at least two layers of glass fiber winding yarn layers are arranged in different winding directions.

The preferable technical scheme is that the supporting layer comprises a glass fiber felt layer, a first glass fiber cloth layer, a glass fiber winding yarn layer and a second glass fiber cloth layer which are sequentially connected in a laminated mode.

The preferable technical scheme is that the upper wrapping layer and the lower wrapping layer are both glass fiber felt layers.

A molding method of a low-pressure molded cage, comprising the steps of:

s1, preparing a die with pins in a die cavity, wherein the pins are in one-to-one correspondence with the pipe holes;

s2, paving phenolic resin in the die cavity;

s3, paving a glass fiber felt, absorbing phenolic resin, compacting and discharging bubbles;

s4, paving glass fiber cloth, absorbing phenolic resin, compacting and discharging bubbles;

s5, winding the prestressed glass fiber yarns along the pins;

s6, repeatedly discharging bubbles to the glass fiber yarns, the glass fiber cloth and the glass fiber felt, and extruding redundant resin;

s7, repeating the steps S2-S6 for a plurality of times until the thickness reaches the requirement;

s8, repeating the step S3 on the top layer;

s9, pressing the multi-layer glass fiber felt, the glass fiber cloth and the glass fiber yarn to compact the multi-layer glass fiber felt, the glass fiber cloth and the glass fiber yarn;

s10, heating, solidifying and exhausting;

s11, demolding and standing;

s15, finish turning and reaming finally.

In the preferred technical scheme, in the step S2, the high-temperature curing raw material is phenolic resin.

The preferable technical proposal is that a step S12 and a second heating are arranged between the steps S11 and S15, and the curing is performed again.

The preferable technical scheme is that a step S13 and rough turning are arranged between the steps S12 and S15, and preliminary reaming is carried out on the pin holes.

The preferable technical proposal is that a step S14 and a third heating and shaping are arranged between the steps S13 and S15.

The preferable technical scheme is that in the step S9, weight of 10 tons per square meter is applied to the multi-layer glass fiber felt, the glass fiber cloth and the glass fiber yarn through a press.

The invention has the advantages and beneficial effects that: the low-pressure forming retainer and the forming method thereof have reasonable structure, the short fiber layer and the long fiber layer are combined, the short fiber absorbs enough phenolic resin to improve the glue content, the connection firmness with the graphite tube is ensured, and the long fiber is used for improving the supporting strength of the product; the short fiber layer and the long fiber layer are laid layer by layer and compacted to discharge bubbles, so that the tonnage requirement of the press is reduced when the final product is compacted and molded.

Drawings

FIG. 1 is a schematic view showing the structure of an embodiment 1 of a low-pressure molded cage and a molding method thereof according to the present invention;

fig. 2 is a schematic structural view of the holder body in embodiment 1;

FIG. 3 is a winding pattern of the glass yarn of example 1;

fig. 4 is a schematic view of the layered structure of the cage body in embodiment 1;

FIG. 5 is a schematic view of the structure of a support layer in example 2;

FIG. 6 is a schematic view of the structure of a support layer in example 3;

FIG. 7 is a cross-sectional view of step S1 of example 1;

FIG. 8 is a cross-sectional view of step S2 of example 1;

FIG. 9 is a cross-sectional view of step S3 of example 1;

FIG. 10 is a cross-sectional view of step S4 of example 1;

FIG. 11 is a sectional view of step S5 of example 1;

FIG. 12 is a schematic view of the structure of a mold in example 4;

FIG. 13 is an exploded cross-sectional view of the mold of example 4;

in the figure: 1. a holder body; 11. pipe holes; 12. bolt holes; 2. a glass fiber felt layer; 3. a first fiberglass cloth layer; 4. a glass fiber winding yarn layer; 5. a second fiberglass cloth layer; 6. a graphite tube; 7. a heater; 71. a dilute sulfuric acid inlet; 72. a concentrated sulfuric acid outlet; 73; a steam inlet; 74. a steam outlet; 8. glass fiber yarn; 9. a mold; 91. a phenolic resin; 92. a pin; a1, an air bag; a2, winding paper; a3, a vent hole; a4, an air pressure sensor.

Detailed Description

The following describes the embodiments of the present invention further with reference to the drawings and examples. The following examples are only for more clearly illustrating the technical aspects of the present invention, and are not intended to limit the scope of the present invention.

In the description of the present invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "horizontal," "vertical," "top," "outer," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, merely to facilitate description of the present invention and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

Example 1

As shown in fig. 1 to 4, the low-pressure forming retainer of the embodiment comprises a retainer body 1, wherein a plurality of pipe holes 11 for a graphite pipe 6 to pass through and bolt holes 12 for fixedly connecting with a heater 7 are formed in the retainer body 1, the retainer body 1 comprises an upper wrapping layer, a supporting layer and a lower wrapping layer which are sequentially connected in a stacked manner, at least one layer of the upper wrapping layer, the supporting layer and the lower wrapping layer is provided with a reinforcing material, the supporting layer is provided with a plurality of groups, and the upper wrapping layer, the supporting layer and the lower wrapping layer are all wrapped with a high-temperature curing material; the reinforcing material is preferably glass fiber, and the high-temperature curing material is preferably phenolic resin.

Through such design, go up parcel layer and lower parcel layer setting in the outside of holder body 1 for the high temperature steam in the straight heater, phenolic resin has both guaranteed to go up the connection between parcel layer, supporting layer and the lower parcel layer, has also improved the intensity of holder body 1 after the solidification.

Specifically, the supporting layer comprises a base material layer and a reinforcing layer which are connected in a laminated mode, the base material layer is a short fiber layer, and the base material layer comprises a glass fiber felt layer 2 used for absorbing the phenolic resin.

By the design, the glass fiber felt layer 2 can absorb enough phenolic resin to improve the glue content of the retainer body 1 and the connection firmness between the retainer body 1 and the graphite tube 6; the glass fiber mat layer 2 may be selected from glass fiber mats of 300 to 600 g/square meter, preferably 450 g/square meter.

Specifically, the reinforcing layer is a long fiber layer, and the long fiber layer comprises a first glass fiber cloth layer 3 for absorbing phenolic resin.

Through the design, the strength of the retainer body 1 can be improved by the long fiber layer, and the first glass fiber cloth layer 3 can absorb a small amount of phenolic resin so as to ensure that the first glass fiber cloth layer 3 can be firmly connected with the glass fiber felt layer 2 when a product is formed; preferably, the first glass fiber cloth layer 3 can be a three-dimensional fiber cloth, so that the connection between the first glass fiber cloth layer and the upper and lower layers is firmer, and the firmness along the axial direction of the pipe hole 11 is ensured; the first glass cloth layer 3 may be selected from glass cloth of 200-1000 g/square meter, preferably 600 g/square meter.

Specifically, the long fiber layer further comprises a glass fiber winding yarn layer 4 for absorbing phenolic resin.

Through the design, the strength of the retainer body 1 is further improved by the glass fiber winding yarn layer 4, and the glass fiber winding yarn layer 4 absorbs a small amount of phenolic resin so as to ensure that the glass fiber winding yarn layer 4 is firmly connected with the first glass fiber cloth layer 3 when the product is molded; the first glass fiber cloth layer 3 is matched with the glass fiber winding yarn layer 4 to reduce the glue content of the retainer body 1, so that the defect that the strength of the retainer body 1 is insufficient due to the fact that the glue content of the retainer body 1 is too high is avoided; preferably, the fiber content is between 70 and 80%; the glass fiber wound yarn layer 4 may be selected from 1200-4800 tex glass fiber yarns, preferably 2400tex glass fiber yarns.

Further, the glass fiber winding yarn layer 4 is wound outside the pipe hole 11.

By such a design, the strength around the tube hole 11 is further improved to ensure sufficient support for the graphite tube.

Further, at least two layers of the glass fiber winding yarn layers 4 are arranged differently in the winding direction.

Through such design, the retainer body 1 can be effectively supported in all radial directions, and the support force of the retainer body 1 in the radial direction is prevented from being too single.

Specifically, the glass fiber felt layer 2, the first glass fiber cloth layer 3 and the glass fiber winding yarn layer 4 are sequentially laminated and connected.

By such a design, the fiber length is gradually increased as seen in the axial direction of the product, and the strength of each layer is increased layer by layer, thereby improving the strength of the product.

Specifically, the upper wrapping layer and the lower wrapping layer are both glass fiber felt layers 2.

By the design, the first glass fiber cloth layer 3 or the glass fiber winding yarn layer 4 is prevented from being positioned at the outer side, and the product is easy to be stripped after being solidified due to the smaller phenolic resin content; the glass fiber felt layer 2 can absorb enough phenolic resin, and the product is solidified to ensure the whole firmness of the product.

A molding method of a low-pressure molded cage, comprising the steps of:

s2, paving phenolic resin in the die cavity;

s5, winding the prestressed glass fiber yarns 8 along the pins;

s6, repeatedly discharging bubbles to the glass fiber yarns 8, the glass fiber cloth and the glass fiber felt, and extruding redundant resin;

s8, repeating the step S3 on the top layer;

s10, heating, solidifying and exhausting;

s11, demolding and standing;

s12, heating for the second time, and curing again;

s13, rough turning, namely primarily reaming the pin holes;

s14, heating for the third time and shaping;

s15, finish turning and reaming finally.

Further, in step S1, a mold support is arranged at the bottom of the mold, which can bear 100 tons of pressure and has a heating function, and the mold cavity is heated at 80-100 ℃; in the step S2, phenolic resin is in a liquid state, and phenolic resin for mould pressing in the prior art is in a solid state and can be used after being heated; in the steps S3 and S4, the glass fiber felt and the glass fiber cloth are cut into circles matched with a die, punched holes matched with pins are punched by a punching machine, and the compaction and bubble removal of the glass fiber felt and the glass fiber cloth can be operated by using a small press roll; in the step S6, bubbles can be removed repeatedly by using a pressing knife and a pressing plate, the shape and the size of the pressing plate are matched with those of the die, and the pressing plate can be a steel plate with the thickness of 20 mm-30 mm; in step S8, in order to ensure that glass fiber mats are arranged on both sides of the product, the glass fiber mats are required to be paved on the last top layer; in the step S9, a press machine can be used for pressing a plurality of layers of glass fiber felts, glass fiber cloths and glass fiber yarns, and the pressing strength is ensured to be 10 t/square meter; in step S10, the curing process is performed twice; in step S11, the mold is released and left for four days or more.

Through the steps, the glass fiber felt, the glass fiber cloth and the wound glass fiber yarn are sequentially placed in the die, redundant phenolic resin is extruded layer by layer to discharge bubbles, the bubbles are compacted, the steps are repeated until the thickness requirement of a product is met, and finally, a layer of glass fiber felt is placed, so that the product is wrapped by the glass fiber felts of the top layer and the bottom layer, and the product is heated, solidified and formed.

In the steps S2, S3 and S4, glass fiber felt and glass fiber cloth can be paved firstly, phenolic resin is paved later, and after the glass fiber felt and the glass fiber cloth absorb the phenolic resin for a period of time, the glass fiber felt and the glass fiber cloth are compacted and discharged with bubbles.

In the steps S3 and S4, the glass fiber mat and the glass fiber cloth may be sewn together in advance by glass fiber threads, so that the strength of the retainer body 1 in the axial direction can be enhanced, and the glass fiber threads provide the axial tension to the retainer body 1.

The glass fiber yarns can be vertically penetrated in the glass fiber felt and the glass fiber cloth when being wound, so that the strength of the retainer body 1 in the axial direction is enhanced.

The glass fiber yarn with prestress is the glass fiber yarn under the state of being straightened, and the prestress of the glass fiber yarn is as follows: 20-100 newtons.

In order to facilitate demoulding in the step S11, the pin adopts a round table shape with a small upper part and a large lower part, and in order to prevent glass fiber yarns from sliding out of the pin, the diameter difference between the upper end and the lower end of the pin is 0.5mm.

The retainer body 1 is stressed as follows when in use: firstly, the retainer body 1 needs to bear the self gravity of the graphite tube 6; thirdly, the retainer body 1 also needs to bear the weight of sulfuric acid flowing in the graphite tube 6; finally, the cage body 1 also needs to bear the impact force of the high-temperature steam on the graphite tube 6.

Dilute sulfuric acid enters the graphite tube 6 from the dilute sulfuric acid inlet 71 and is discharged from the concentrated sulfuric acid outlet 72; the high-temperature steam enters the heater cavity from the steam inlet 73 to heat the graphite tube 6, the graphite tube 6 transfers heat to the dilute sulfuric acid in the interior of the graphite tube to evaporate the water of the dilute sulfuric acid, the purpose of concentrating the dilute sulfuric acid is achieved, and the cooled steam is discharged from the steam outlet 74.

Example 2

As shown in fig. 5, embodiment 2 differs from embodiment 1 in that: the support layer comprises a glass fiber felt layer 2, a first glass fiber cloth layer 3, a glass fiber winding yarn layer 4 and a second glass fiber cloth layer 5 which are sequentially connected in a laminated mode.

Through such design, from the axial direction of holder body 1, the lamellar structure is glass fiber felt layer, glass fiber cloth layer, glass fiber winding yarn layer, glass fiber cloth layer, glass fiber felt layer, glass fiber cloth layer, glass fiber winding yarn layer, glass fiber cloth layer so circulated down, and holder body 1 wholly is symmetrical setting, therefore holder body 1 does not have the directionality, and it installs in the heater can not have the problem of installation direction, leads to the longer phenomenon of life when certain face is towards inside.

Example 3

As shown in fig. 6, embodiment 3 differs from embodiment 1 in that: the support layer comprises a glass fiber felt layer 2, a glass fiber winding yarn layer 4 and a first glass fiber cloth layer 3 which are sequentially connected in a laminated mode.

Example 4

As shown in fig. 12 to 13, embodiment 4 is based on embodiment 1, except that: the novel winding device comprises a die provided with a die cavity, wherein a wound piece is arranged in the die cavity, and the retainer body and the wound piece are arranged in a manner of being easy to separate.

Through the design, the phenolic resin is convenient to separate from the die after being heated and solidified; the winded piece is usually a pin, the pin can be designed into a round table shape with a small upper part and a large lower part, and in order to reduce the phenomenon of upward sliding when the glass fiber yarns are wound, the diameter difference between the upper end face and the lower end face of the pin is small.

The wound piece comprises an inner core connected with the die and an easy-turning piece sleeved outside the inner core, the easy-turning piece is arranged with the inner core in an easy-to-separate mode, and the glass fiber yarns are wound outside the easy-to-turn piece.

Through the design, before the step S2, the easy-turning piece is sleeved outside the inner core, and then the steps S2 and the like can be started; when the phenolic resin is solidified in the step S10, the easy-turning piece is separated from the inner core during demolding of the product, the easy-turning piece is synchronously demolded with the product, and the easy-turning piece is turned in the step S13 and the step S15, so that the normal structure and the use of the retainer body 1 are not affected.

The inner core is an air bag a1, the easy turning piece is a roll paper a2, and the die 9 is provided with a vent hole a3 for inflating and deflating the air bag a 1.

Through the design, the air bag a1 is inflated to form an inner core, the roll paper a2 is sleeved outside the air bag a1, and the glass fiber yarn is wound outside the roll paper a 2; the roll paper a2 has a certain hardness so that the roll paper a2 is not obviously deformed during winding, kraft paper is preferable, the combustion point of the kraft paper is 190 ℃, the temperature of heating and curing is 80-100 ℃, and spontaneous combustion of the roll paper a2 is not caused.

The inner cavity of the air bag a1 is provided with an air pressure sensor a4.

By such design, when the roll paper a2 receives the pressure of the glass fiber yarn winding, the roll paper a2 slightly contracts and deforms, the air bag a1 is pressed, and the air pressure changes; the air bag a1 not only can play a supporting role, but also can detect the prestress of the winding of the glass fiber yarn through the air pressure sensor a4, so that the purpose of timely adjusting the tightening force of the glass fiber yarn is achieved.

Comparative example

In the prior art, the compression molding process mainly depends on the compactness of the product and the strength of glass fiber short filaments (cut filaments), so that the product strength is formed, the material strength of the molded product is about 80Mpa-100Mpa, the prepreg producer intermittently produces the cut filaments due to small product quantity, and the cut filaments belong to the leftovers in the production process of glass fiber wiredrawing weaving, and the technical parameters of the cut filaments are unstable, so that the quality of the flower plate product is unstable.

	Product strength	Molding pressure requirement
			Example 1	120-180Mpa	10t/㎡
Example 2	120-190Mpa	50t/㎡
			Example 3	130-200Mpa	100t/㎡
Comparative example	80Mpa-100Mpa	1000t/㎡

In summary, example 1, example 2, example 3 showed improved product strength and reduced molding pressure requirements compared to the comparative examples; example 1, although somewhat lower in product strength than examples 2 and 3, is adequate to meet customer requirements and has low molding pressure requirements.

The foregoing is merely a preferred embodiment of the present invention, and it should be noted that it will be apparent to those skilled in the art that several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the scope of the invention.

Claims

1. The utility model provides a low pressure shaping holder, includes holder body (1), be provided with tube hole (11) and be used for with heater (7) fixed connection that a plurality of supplies graphite pipe (6) to pass on holder body (1), its characterized in that, holder body (1) are including last parcel layer, supporting layer and the lower parcel layer of laminating connection in proper order, at least one of going up parcel layer, supporting layer and lower parcel layer is provided with reinforcing material, the supporting layer is provided with a plurality of group, it is provided with high temperature curing material to go up parcel layer, supporting layer and the equal parcel of lower parcel layer.

2. The low pressure molded cage of claim 1 wherein the support layer comprises a base layer and a reinforcing layer in laminated connection, the base layer being a staple fiber layer comprising a fiberglass mat layer (2).

3. The low pressure formed holder according to claim 2, characterized in that the reinforcement layer is a long fiber layer comprising a first glass fiber cloth layer (3).

4. The low pressure forming cage according to claim 2, characterized in that the reinforcing layer is a long fiber layer comprising a layer of glass fiber wound yarn (4).

5. The low-pressure forming retainer according to claim 2, wherein the reinforcing layer is a first glass fiber cloth layer (3) and a glass fiber winding yarn layer (4), and the glass fiber felt layer (2), the first glass fiber cloth layer (3) and the glass fiber winding yarn layer (4) are sequentially laminated or the glass fiber felt layer (2), the glass fiber winding yarn layer (4) and the first glass fiber cloth layer (3) are sequentially laminated.

6. The low pressure molded holder according to claim 4 or 5, wherein the glass fiber yarn of the glass fiber wound yarn layer (4) is provided on the outer periphery of the tube hole (11).

7. The low-pressure molded holder according to claim 6, wherein the winding directions of at least two of the glass fiber wound yarn layers (4) are arranged differently.

8. The low pressure forming cage according to claim 2, characterized in that the support layer comprises a glass fiber mat layer (2), a first glass fiber cloth layer (3), a glass fiber wound yarn layer (4) and a second glass fiber cloth layer (5) which are connected in sequence.

9. The low pressure molded cage according to claim 1, characterized in that the upper and lower wrapping layers are both fiberglass mat layers (2).

10. A molding method of a low-pressure molded cage, comprising the steps of:

s2, paving a liquid high-temperature curing raw material into the die cavity;

s3, paving a glass fiber felt, absorbing the high-temperature curing raw material, compacting and discharging bubbles;

s4, paving glass fiber cloth, absorbing high-temperature curing raw materials, compacting and discharging bubbles;

s5, winding the prestressed glass fiber yarns along the pins;

s6, repeatedly discharging bubbles to the glass fiber yarns, the glass fiber cloth and the glass fiber felt;

s8, repeating the step S3 on the top layer;

s10, heating, solidifying and exhausting;

s11, demolding and standing;

s15, turning and finally reaming.

11. The method of forming a low pressure molded cage according to claim 10, wherein in step S2, the high temperature curing raw material is a phenolic resin.

12. The method of forming a low pressure molded cage according to claim 10, wherein step S12, a second heating, and a resolidification are provided between steps S11 and S15.

13. The method of forming a low pressure molded cage according to claim 12, wherein step S13, rough turning, preliminary reaming of the pin holes are provided between steps S12 and S15.

14. The method of claim 13, wherein step S14 and third heating are provided between steps S13 and S15, and the molded article is formed.

15. The method of forming a low pressure forming holder according to claim 10, wherein step S9 applies a weight of 10 tons per square meter to the multi-layered glass fiber mat, glass fiber cloth, glass fiber yarn by a press.