JPH05106182A - Nozzle for separating impurities in pulp and production of the nozzle - Google Patents

Abstract

PURPOSE:To improve the durability of the title nozzle by preventing an impurity outlet from erosion due to a fluid containing e.g. sand separated from pulp within the nozzle. CONSTITUTION:A ceramic cylinder 20 is engaged with the inner periphery 12a of an impurity outlet 12 at the tip on the smaller diameter side of a resinous tapered nozzle body 10 and checked with the inner hook 32 of an annular holder 30 caulked on the outer periphery 12b of the outlet 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nozzle used in a centrifugal foreign matter separation (screen) device for separating and discharging foreign matter such as mixed sand from pulp cooked in a papermaking process, and a method for producing the same. It is about.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 8, a nozzle for a foreign matter separating device for pulp is made of a resin material such as polypropylene and is provided in a peripheral wall with a tangential inlet 101.
About 100 liters per minute of pulp after cooking flows from the pulp and is subjected to a centrifugal separation action by swirling the inside, and a liquid containing sand or the like from the separated foreign matter outlet 102 at one end in the longitudinal direction is about 80 liters per minute, and the other end. It is known that about 80 liters of high-quality pulp flows out from the pulp outlet 103 of the above.

[0003]

However, since the above-mentioned conventional nozzle is entirely made of a resin material, the separated foreign matter outlet port 10 through which the liquid containing sand or the like flows out while swirling.
The tapered inner peripheral surface of No. 2 is significantly eroded, and for example, in the case of a fast one, the diameter of the separated foreign matter outlet 102 may increase from φ18 to φ22 when it is a new one in a year and a half. There was a problem that the processing flow rate of pulp was drastically reduced. Further, in order to deal with such a problem, the inner peripheral surface of the separated foreign matter outlet 102 may be formed of an annular body having high wear resistance, but since the separated foreign matter outlet 102 receives a high discharge pressure, It is the current situation that the joint portion between the main body made of a resin material and the annular body has to be able to withstand this discharge pressure and has not been put to practical use.

The present invention has been made in view of the above problems, and an object thereof is to prevent erosion of a foreign matter outlet by a liquid containing sand or the like separated from pulp,
It is to improve durability.

[0005]

In order to solve the above-mentioned problems, the present invention uses ceramics on the inner peripheral surface of the foreign matter outlet formed at the end on the small diameter side of the tapered nozzle body made of a resin material. The present invention provides a nozzle for a pulp foreign matter separating device, in which the cylindrical body is fitted and the cylindrical body is prevented from coming off by an inner diameter flange portion of an annular holder fixed by caulking to the outer circumferential surface of the foreign matter outlet.

In addition, as a method of manufacturing the above nozzle, a nozzle body formed of a resin material is rotated while a peripheral surface of a foreign matter outlet opening at one longitudinal end thereof is supported by a bearing, The step of cutting the inner peripheral surface of the foreign substance outlet into a cylindrical shape, and the cylindrical body made of ceramics is press-fitted into the inner peripheral surface of the foreign substance outlet of the nozzle body, and the outer diameter cylindrical portion of the metal holder having the inner diameter flange portion is A step of fitting the outer diameter surface of the foreign matter outlet of the nozzle body against the outer end surface of the cylindrical body, and crimping the outer diameter cylindrical portion to the outer circumference surface of the foreign matter outlet of the nozzle body; The present invention provides a method for manufacturing a nozzle for a foreign matter separating device for pulp, which comprises:

[0007]

According to the nozzle of the present invention, a cylindrical body made of ceramics is fitted on the inner peripheral surface of the foreign matter outlet main body made of a resin material. Since this cylindrical body has high abrasion resistance, the pulp The erosion due to the liquid containing sand and the like separated from is suppressed. Further, since the cylindrical body is firmly fixed by the holder fixed by caulking to the foreign matter outlet body, it does not separate from the nozzle body even if it receives a high discharge pressure and flow resistance due to the liquid.

Since the resin material is relatively flexible, it is generally very difficult to machine it with high precision into a hollow cylinder, but according to the manufacturing method of the present invention, the resin material is used. While the outer peripheral surface of the foreign substance outlet of the nozzle body is supported by the bearing, the inner peripheral surface is hollowed out, so it is possible to cut into a highly accurate cylindrical shape. The surface and the outer peripheral surface of the cylindrical body made of ceramics can be closely fitted.

[0009]

FIG. 1 shows an embodiment of a nozzle for a foreign material separating device for pulp according to the present invention, in which 10 is a taper shape as a whole, and is tangential to the peripheral wall on the large diameter side. Inlet 11 and foreign matter outlet 12 opened at the end of the small diameter side
And a pulp outlet 13 formed at the center of the end on the large diameter side, the pulp outlet 13 is formed of polypropylene, and the other portion is formed of polyethylene.

As shown in FIG. 2, a cylindrical body 20 made of ceramics such as SiC (silicon carbide) is press-fitted into the inner peripheral surface 12a of the cylindrical foreign matter outlet 12 through a sealant layer, that is, a liquid packing layer 70. It is fitted. An inner peripheral surface 21 and an outer peripheral surface 22 of the SiC cylindrical body 20 are formed in a straight cylindrical surface shape, and a chamfered portion 23 is formed at an inner end portion of the inner peripheral surface 21. By the portion 23, the step with the tapered inner peripheral surface 10a of the nozzle body 10 is made gentle.

Reference numeral 30 denotes an outer diameter cylindrical portion 31 fitted into the outer peripheral surface 12b of the foreign matter outlet 12, and one end of the outer diameter cylindrical portion 31 and caulking engaged with the outer peripheral step portion 12c of the foreign matter outlet 12. An annular metal holder having a substantially L-shaped cross section, which has a portion 33 and an inner diameter flange portion 32 extending from the other end of the outer diameter cylindrical portion 31 and having an inner diameter portion abutting the outer end surface 24 of the SiC cylindrical body 20,
The SiC cylindrical body 20 is prevented from coming off from the nozzle body 10.

According to the configuration of the above embodiment, the nozzle body 1
The liquid containing sand and the like separated from the pulp by the swirling flow in 0 is discharged through the inner circumference of the SiC cylindrical body 20 at the foreign matter outlet 12, and the SiC cylindrical body 20 has high wear resistance. Therefore, erosion due to fluidized sand or the like is unlikely to occur, and therefore, good processing capacity can be maintained for a long period of time. It should be noted that the prototype having the configuration of the above-described embodiment and the conventional product in which the foreign matter outlet is made of polyethylene alone are 10
After actually using the product for several months, the change in the diameter of the foreign matter outlet was measured.
While abrasion of about mm was observed, it was confirmed that the prototype hardly changed the diameter due to abrasion of the SiC cylindrical body 20.

Further, since the inner peripheral surface 21 of the SiC cylindrical body 20 is a straight cylindrical surface and the chamfered portion 21a moderates the step with the inner peripheral surface of the nozzle body 10,
The outflow pressure and flow resistance acting on the SiC cylindrical body 20 due to the outflow of the liquid containing sand etc. are alleviated, and the cylindrical body 20
Is firmly fixed by the holder 30, so that it does not come off from the nozzle body 10. Further, since the holder 30 is caulked and fixed to the outer peripheral step portion of the foreign substance outlet 12 of the nozzle body 10, the holder 30 due to the sand or the like that has flowed out.
The amount of wear of itself is extremely small, so the SiC cylinder 2
Demonstrate high holding power for zero.

The method of manufacturing the nozzle having the above structure will be described in the order of steps. In manufacturing the SiC cylindrical body 20,
First, the base material, which is a mixture of SiC powder and C (carbon) powder, and the reaction material, which is made of Si (silicon) powder, are weighed according to the number of products manufactured. The measured base material and reactive material are press-molded under heating conditions of 180 ℃ x 2min. As shown in FIG. 3, the molded body 20A of the base material is molded into a cylindrical shape, and the molded body 20B of the reaction material is the molded body 20A of the base material.
Is formed into a flat annular shape having a larger diameter.

Next, the base material molded body 20A and the reaction material molded body 20B are sintered (calcined) under heating conditions of 1500 ° C. × 2 Hr in separate vacuum sintering furnaces, and the calcined substrate is Molded body 2
The inner peripheral surface 21A, the outer peripheral surface 22A, and the chamfered portion 23A are turned from 0A by a lathe. Then, the calcinated reaction material molded body 20B and the base material molded body 2 which is calcinated and turned.
As shown in FIG. 4, 0A is alternately stacked on the carbon plate 40, and this is sintered (reaction sintering) under a heating condition of 1500 ° C. × 2 Hr in a vacuum sintering furnace. As a result, the reaction material reacts and infiltrates the base material molded body 20A as follows. (SiC + C) + Si → (SiC + Si) + C

Excess Si as shown in FIG. 5A is deposited on the surface of the reaction-sintered base material compact 20A. This excess Si cannot be removed with an air gun, so caustic soda
A salt bath treatment of immersing the base material molded body 20A in NaOH is performed, that is, as shown in FIG. 5B, excess Si is floated by forming a surface corrosion layer on the base material molded body 20A. As shown in (c), the base material molded body 2 is formed by jetting a shot material composed of air, water, and an abrasive material.
SiC cylindrical body 2 after removing the surface corrosion layer and excess Si from 0A
The production of 0 is completed.

On the other hand, the preformed nozzle body 10 is
As shown in FIG. 6A, the outer peripheral surface 12b of the foreign matter outlet 12 is turned into a cylindrical surface while being centered and supported by the center push 50, and further, as shown in FIG. The inner peripheral surface 12a of the foreign matter outlet 12 is turned into a cylindrical surface shape while the 12b is supported by a steadying bearing 60. According to this turning method, since the nozzle body 10 made of polyethylene, which is a relatively flexible resin material, does not run around unstablely due to cutting resistance during turning.
It can be processed with high precision.

Next, as shown in FIG. 7, the nozzle body 10
After applying the liquid packing 70 to the turned inner peripheral surface 12a of the foreign matter outlet 12 of the above, the SiC cylindrical body 20 is press-fitted, and further, a steel annular body such as SUS316 is cut in advance, or The outer diameter cylindrical portion 31 of the holder 30, which is formed into an L-shaped cross section by press molding, is fitted into the turned outer peripheral surface 12b of the foreign matter outlet 12, and the holder 3
The inner diameter collar 32 of 0 abuts on the outer end surface 24 of the SiC cylindrical body 20. Then, in this state, while rotating with a lathe, the outer diameter cylindrical portion 31 is squeezed with a roller, or a caulking die is used to form the outer peripheral stepped portion 12 of the foreign matter outlet 12.
Caulk to c.

The present invention is not limited to the above embodiment. For example, the cylindrical body 20 may be made of ceramics other than SiC, and the shape of other details may be arbitrary, and various changes may be made to each manufacturing process.

[0020]

As is apparent from the above description, since the pulp foreign matter separating apparatus nozzle according to the present invention has the cylindrical body made of ceramic mounted at the foreign matter outlet port,
Corrosion of the foreign matter outlet due to the liquid containing sand and the like separated from the pulp is suppressed, and since the cylindrical body does not separate from the nozzle body due to the outflow pressure or flow resistance of the liquid, it is an excellent treatment for a long period of time. You can exert your ability.

Further, according to the manufacturing method of the present invention, since the outer peripheral surface of the foreign matter outlet is supported by the bearing when the foreign matter outlet of the nozzle body made of the resin material is hollowed out, the foreign matter outlet is flexible. Despite this, it does not shake unstable due to cutting resistance, and it is possible to cut into a highly accurate cylindrical shape.Therefore, the inner peripheral surface of the foreign matter outlet and the outer peripheral surface of the cylindrical body made of ceramics are closely contacted. Can be mated,
The sealing property of the fitting surface can be improved.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view showing an embodiment of a nozzle of the present invention.

FIG. 2 is likewise an enlarged cross-sectional view of a main part.

FIG. 3 is an explanatory view showing a process of forming a base material and a reaction material of a SiC cylindrical body in manufacturing a nozzle.

FIG. 4 is an explanatory view showing a reaction sintering step in the same manner.

FIG. 5 is an explanatory view showing a surface corrosion layer and excess Si removing step.

FIG. 6 is an explanatory view showing a turning step of the foreign matter outlet of the nozzle body.

FIG. 7 is an explanatory diagram showing a nozzle assembling process.

FIG. 8 is a partially cutaway front view showing an example of a nozzle having a conventional structure.

[Explanation of symbols]

 10 Nozzle body 11 Inlet 12 Foreign matter outlet 12a, 21 Inner peripheral surface 12b, 22 Outer peripheral surface 13 Pulp outlet 20 SiC cylindrical body 24 Outer end surface 30 Holder 31 Outer diameter cylindrical portion 32 Inner diameter flange portion 33 Caulking portion 60 Bearing 70 Liquid Packing

Claims (2)

[Claims] 1. A cylindrical body made of ceramics is fitted to an inner peripheral surface of a foreign matter outlet port formed at an end portion of a tapered nozzle body made of a resin material on a small diameter side, and the cylindrical body is fitted with the foreign matter outlet port. Nozzle for a foreign matter separating apparatus for pulp, characterized in that the nozzle is prevented from coming off by an inner diameter flange portion of an annular holder which is fixed by caulking to the outer peripheral surface of the. 2. A nozzle main body made of a resin material is rotated with a peripheral surface of a foreign matter outlet port opened at one longitudinal end thereof being supported by a bearing, and the inner peripheral surface of the foreign matter outlet port is formed into a cylindrical shape. Cutting process, press the cylindrical body made of ceramics into the inner peripheral surface of the foreign substance outlet of the nozzle body, and fit the outer cylindrical portion of the metal holder with the inner diameter flange to the outer peripheral surface of the foreign substance outlet of the nozzle body. And abutting the inner diameter flange portion against the outer end surface of the cylindrical body, and crimping the outer diameter cylindrical portion to the outer peripheral surface of the foreign matter outlet of the nozzle body, the foreign matter separation of the pulp. Method for manufacturing device nozzle.