RU2561545C1 - Chain for chain curtain of roasting unit - Google Patents

Abstract

FIELD: heating.

SUBSTANCE: invention relates to intrafurnace technical devices for intensification of a roasting process in rotating furnaces. A chain includes welded or cast links of oval or round shape, which are connected to each other. Body of each of the links has a cross section with a profile of a round shape. Each link on the side of its outer surface has a cross-section equal to 0.5d, where d is a rod gauge equal to 19-28 mm. On the side of the inner surface, the link has a radius equal to half pitch of the chain for round links, or with radius R equal to 0.5 (B-2b), where B is width, b is thickness of the link body, for oval links. Closure of outer and inner surfaces of links is provided by their flat surfaces.

EFFECT: reduction of abrasive wear at connection points of chain links and improvement of resistance of the chain to break.

4 cl, 4 dwg

Description

The invention relates to in-furnace technical devices for intensification of the firing process in rotary kilns, in particular, to the design of chains for regenerative heat-exchange chain curtains and can be used in the building materials industry, non-ferrous metallurgy, pulp and paper industry, clinker, alumina, lime and other materials.

From the existing level of technology it was found that the most common structural elements used in the manufacture of chain heat exchangers are round-link or oval chains made of a bar of cylindrical shape (GOST 7070-75, GOST 228-79 (ST SEV 713-83), GOST 13237 -67, GOST 5-1925-73, Auto St. 614311, 07/05/78 Bul. 25, TU 4884-002-39004563-2008, SU 330321, 12/27/1966; SU 450947, 03/12/1973; Khodorov E. I. Furnaces of the cement industry. - L .: Stroyizdat, 1968, pp. 59-61; O. Nesvizhsky. Durability of wear parts of cement equipment. - M.: Mashinostro Niye, 1968, pp. 179-193; Satarin V.I. et al. Cement industry abroad. - Moscow: Gosstroyizdat, p. 113; US 3427801, 02/18/1969; GB 1100831, 01/24/1968; EAPO 010711, 03/31/2008). All these chain designs are designed to provide intensification of heat and mass transfer processes and pay almost no attention (mention in passing) to abrasive wear, especially at the joints of the links. The chain curtains in heat exchangers are divided into three zones: hot - up to 1200 ° C, warm - up to 800 ° C and cold - 200 ° C. In the hot zone, especially for oval links, the degree of oxidation of the entire surface of the links and abrasive wear at the joints are comparable. To reduce the degree of oxidation of the surface of the chain links located in the hot zone, they are made of heat-resistant steel. In the warm and cold zones of the heat exchange unit, abrasive wear prevails at the joints of the chain links and the maximum contact surface appears when about one third of the caliber of the link body is lost, the wear of the external surfaces of the link is both abrasive and oxidative. In connection with the foregoing, the loss of one third of the caliber of the body of the links leads to a decrease in strength, which can lead to breakage of the chain linkage and an emergency stop of the unit. Therefore, along with the performance of the heat transfer function, transporting ability, the circuit must have abrasion resistance to increase the life of the furnace.

Known chains for chain curtains of rotary kilns containing interconnected links (RF patent for utility model No. 106343, IPC F27B 7/20, application form 08.02.2011, publ. 07/10/07/2011, "Chain for a chain curtain of a rotary kiln ”, No. 110172, IPC F27B 7/20, declared May 25, 2011, published November 10, 2011,“ Chain for a heat-exchange chain curtain of a rotary kiln ”). Known chains of welded links of a round or oval shape with a round or oval cross-section of the links are not effective enough, they are destroyed in the processed medium due to abrasive wear of the links.

A disadvantage of the known section profiles of the chain link body is the intensive wear of the link at the linking point of the links due to the formation of the point shape of the contact spot with the same curvature of the links equal to the caliber of the link body, which does not give a significant development of the contact spot area, as a result of which the wear rate over the contact The stain remains constant and high enough.

The closest in technical essence and the achieved effect to the claimed technical solution is a chain consisting of welded or cast links, oval or round in shape, the body of each of which has a cross section with a round shape, made with hardening by a special heat treatment technology, either with an increase in the cross section of the contacting surfaces of the rounding sectors of the links and, accordingly, with an increase in the strength of the internal surfaces of the rounding sectors of the links, works for mutual abrasion (Glukauf magazine in Russian, No. 1 (2), May 2000, p. 36, p. 38). It should be noted that among the considered analogues only Glukauf offers measures to increase the service life of the chains.

However, such a chain is also short-lived due to the fact that in the place of maximum curvature the contact spot has a point shape, which leads to intensive wear of the links.

The objective of the invention is the creation of such a chain for the chain curtain of the firing unit, which has improved characteristics for abrasive wear, has high performance due to increased service life.

The technical result that allows to solve this problem is to reduce abrasive wear at the joints of the chain links, increasing the chain resistance to rupture.

In addition, the applicant set himself the task of expanding the arsenal of technical means to ensure the manufacture of the chain for the chain curtain of the firing unit, therefore, an additional technical result consists in the implementation of this purpose.

The problem is achieved in that in the chain for the chain curtain of the firing unit, containing interconnected links, welded or cast, oval or round in shape, the body of each of which has a cross section with a round profile, according to the invention, the cross section of each link on its side the outer surface is made equal to the caliber of the Gostov rod to half the diameter, and from the side of the inner surface, with a radius equal to half the chain pitch for round links, or a radius equal to half the inner their surfaces of the sectors of the rounding of the oval chain links, and the closure of the outer and inner surfaces is provided by flat surfaces.

The body of the chain links of a round shape in any of its cross section can be made with a profile of constant size.

The body of the chain links of an oval configuration in cross sections of straight sections can be made with a profile of constant size.

Mutual closures of surfaces can be made with rounding.

Studies on patent and scientific and technical sources of information indicate that the proposed chain for a chain curtain of a firing unit is not known and does not follow explicitly from the studied prior art, i.e. meets the criteria of "novelty" and "inventive step".

The proposed chain for the chain curtain of the firing unit can be manufactured at any enterprise specializing in this industry, as this requires well-known materials and standard equipment, widely produced by domestic and foreign industry.

Thus, the inventive chain for the chain curtain of the firing unit meets the criterion of "industrial applicability".

Performing a cross section of each link from the side of its outer surface, equal to the caliber of the Gostov rod to half the diameter, and from the side of the inner surface, with a radius equal to half the chain pitch for round links, or a radius equal to half the inner surfaces of the rounding sectors of the oval chain links, allows to reduce abrasive wear at the joints of the chain links, to increase the chain resistance to rupture, which, in turn, increases the performance of the chain by increasing its life but services.

Ensuring the closure of the outer and inner surfaces of the links with flat surfaces also reduces abrasive wear at the joints of the chain links and thereby increases the life of the entire chain.

The implementation of the body of the links of a circular shape in any of its cross section with a profile of constant size allows you to use the rolled gauge of a given profile for welded links and simplifies the manufacture of tooling for cast.

The implementation of the body of oval-shaped links in any of their cross sections of straight sections with a profile of constant size allows the use of a rolled gauge of a given profile for welded links and simplifies the manufacture of tooling for cast.

The mutual closure of flat surfaces with a curved inner surface in the chain link with roundings allows you to get rid of the stress concentrator at the point of their closure and improves the movement of the links relative to each other.

Thus, the set of essential features of the proposed chain for the chain curtain of the firing unit allows to achieve the claimed technical result, namely, reducing abrasive wear at the joints of the chain links, increasing the chain resistance to rupture, therefore, to solve the task - to create such a chain for the chain curtain of the firing unit, which has improved abrasion performance, has high performance due to increased service life.

The invention is illustrated by drawings:

In FIG. 1 shows segments of chains with oval and round links with a profile size section of the link body and configuration at the joints of the chain links.

B - width;

L is the length of the oval link;

D is the outer diameter of the round link;

t is the chain pitch;

b is the thickness of the link body.

In FIG. 2 shows the contact surfaces of the round and oval-shaped links.

A - from a bar of round caliber;

B - from the proposed (claimed) profile of the body of the chain link.

In FIG. 3 shows the construction of the profile size of the body of the oval link.

I - outer surface equal to 0.5d - bar gauge 19 ... 28 mm;

P is the inner surface of radius R equal to 0.5 (B - 2b) (item 1 of Fig. 1) half of the inner surfaces of the sectors of the rounding of the oval links;

W - direct outgoing from quadrants d pos. I;

IV - radius r - (3 ... 5 mm) mating surface pos. P of radius R with straight poses. Sh.

In FIG. 4 shows the construction of the profile of a round link body.

I - outer surface equal to 0.5d - bar gauge 19 ... 28 mm;

P is the inner surface of radius R equal to 0.5 t (item 2 of Fig. 1) half the chain pitch for round links;

W - straight lines coming from quadrants d pos. I;

IV - radius r - (3 ... 5 mm) mating surface pos. P of radius R with straight poses. Sh.

The chain for the chain curtain of the firing unit contains interconnected links, welded or cast, oval 1 or round 2 shape, the body of each of which has a cross section with a round profile, the cross section of each link from the side of its outer surface is made equal to the gauge of the Gostovsky bar to half the diameter, and from the side of the inner surface with a radius equal to half the chain pitch for 2 round links, or a radius equal to half the inner surfaces of the rounding sectors of the oval 1 chain links, cm Poking the outer and inner surfaces is provided by flat surfaces.

The flat oval shape of links 1 and 2 determines the place of their articulation in the oval section of the links. With different curvatures of the oval portions at the junction, the point contact shape of FIG. 2 (A) develops and takes the form of a spot, which leads to a decrease in pressure. The decrease in pressure, in turn, leads to a decrease in the rate of wear. Giving the profile of the link curvature from the side of the inner surface with a radius equal to half the chain pitch for round links, or a radius equal to half the inner surfaces of the rounding sectors of the oval chain links, we increase the contact surface by 450 ... 550 times, which leads to a significant decrease in pressure, reducing them wear at the point of contact.

To create maximum surface contact between the mating links, and accordingly to reduce the friction force, which leads to reduced wear of the link body, it is necessary that the radius of the inner curved surface of the link body be equal to the radius of half the width of the mating oval 1 link, for round 2 - half the pitch of the round link chain (inner diameter of the link).

The construction of the sectional profile of the link body is as follows:

the external surface of the profile is formed by a caliber (bar of cylindrical shape) specified by GOSTs (for curtain chain curtains ⌀ 19 ... 28 mm) up to half the diameter (Fig. 3 pos. I);

the inner surface of the link (pos. II) is performed with a curvature of a radius equal to half the chain pitch for round links, or a radius equal to half the inner surfaces of the rounding sectors of the oval links 1;

the lateral surfaces for mutual intersections of curved surfaces are made (pos. III) - parallel planes extending from half the diameter of the caliber of the outer surface of the profile, smooth articulation of the flat side surfaces of the profile with the inner curved surface is carried out along the radius (pos. IV), depending on the initial caliber of the link and equal to 3-5 mm.

In the known technical solutions are not found these distinctive features in their entirety.

The proposed section body profile of the link can be used without serious difficulties for the manufacture of both welded and cast chains. The proposed profile of the section body for the oval links of the chain is most relevant, this is due to the fact that the contact joint of the oval links occurs on a limited surface due to the configuration of the oval link, in contrast to the round one, where the joint surface can constantly change during operation.

For welded links, rolling the proposed profile of any size at minimum cost (the degree of compression in the finishing stand of the mill to obtain the necessary profile from a round billet -1.1) can be performed by small-grade mills (mill 250, mill 280) of metallurgical and machine-building industries. Restrictions may arise only on hard-deformed steel grades.

Chains with links of the claimed design can be made using well-known casting technologies, including LGM technology, from any steel grades with any standard sizes used in modern production.

When using the original caliber, slightly changed in the claimed version of the profile of the body of the link, familiar to the operators, there is no need to recalculate the mass and number of attached chains for a particular unit.

The use of chains with a link body profile in the claimed embodiment in aggregates of cement and alumina production showed an increase in the service life, depending on the raw material mixture used and the type of fuel, by 2 ... 3 times, which led to a reduction in the cost of equipping furnaces with hanging chains.

Thus, a chain design has been created, the use of which increases the service life of units using hinged chain curtains, which leads to lower costs per unit of output (for example, clinker, alumina).

Claims (4)

1. A chain for a chain curtain of a firing unit, containing welded or cast units of oval or round shape interconnected, the body of each of which has a cross section with a round profile, characterized in that each link from its outer surface is made with a cross section, equal to 0.5d, where d is the bar gauge equal to 19-28 mm, and from the side of the inner surface with a radius equal to half the chain pitch for round links, or with a radius R equal to 0.5 (B-2b), where B is the width, b is the thickness of the link body, for oval links, at than the closure of the outer and inner surfaces of the links is provided by their flat surfaces. 2. The chain according to claim 1, characterized in that the body of the links of a circular shape in any of its cross section is made with a profile of constant size. 3. The chain according to claim 1, characterized in that the body of the oval-shaped links in any of their cross sections of straight sections is made with a profile of constant size. 4. The chain according to claim 1, characterized in that the mutual closure of the surfaces is made with fillets.

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