RU93955U1 - CHAIN FOR CHAIN VALVE OF ROTARY FURNACE - Google Patents

Abstract

 1. A chain for a chain curtain of a rotary kiln, consisting of interconnected links of any geometric shape, where the inner end surface of each link is made curved, characterized in that the outer surface of the cross section of each link is made with ribbing, and the inner surface of the cross section of each link is made with a radius equal to half the chain pitch, or the radius of the curved part of the chain pitch. ! 2. The chain for a chain curtain of a rotary kiln according to claim 1, characterized in that the ribbing is made in the form of ribs bounded by two parabolas, the number of ribs can be any.

Description

The invention relates to heat exchangers, in particular to chain curtains for rotary kilns of the building materials industry.

The most common structural elements used in the manufacture of chain heat exchangers are either round-link or oval chains made of a bar of cylindrical shape. In furnaces of the building materials industry, at the moment, mainly round link chains are used, both welded and cast. (Valberg G.S., Griner I.K., Methododsky V.Ya. Intensification of cement production. -M .; Stroyizdat, 1971, p. 145)

Closest to the claimed technical solution is the chain for a curtain of a rotary kiln known by patent EA 010712, containing round or oval links with flat side surfaces and with inner and outer end surfaces, of which the latter has the shape of a circular cylinder surface, characterized in that each the perimeter link at the junctions of its side surfaces with the outer end surface is made with opposite and counter-directed faces with an inclination at an angle of 40-50 ° in tion link for cross-sectional plane, and the inner end surface is curved. (EA 010712 B1, 10.30.2008)

The disadvantages of the known chain are:

- underdeveloped heat transfer surface, respectively, low heat transfer;

- high metal consumption of the chain, respectively, a high price for it, increased dust formation;

- increased wear on the inner surface of the link.

The technical result of the claimed utility model is the elimination of these disadvantages, namely:

- increase in heat transfer surface and intensification of heat transfer;

- reducing the metal consumption of the chain, respectively, reducing its cost, reducing dust generation, reducing the weight of the rotating part of the furnace, reducing the load on the rollers, bandages and gears of the gearboxes, and therefore reducing the metal consumption of the furnace structure as a whole;

- an increase in the contact surface between the chain links, respectively, a decrease in wear on the inner surface of the link body.

The technical result of the utility model is achieved in that in a chain for a chain curtain of a rotary kiln, consisting of interconnected links of any geometric shape, where the inner end surface of each link is made curved, according to the invention, the outer surface of the cross section of each link is made with ribbing, and the inner the cross-sectional surface of each link is made with a radius equal to half the chain pitch, or the radius of the curved part of the chain pitch.

The fins are made in the form of ribs bounded by two parabolas, the number of ribs can be any.

The implementation of the outer surface of each chain link with fins allows you to increase the heat transfer surface and intensify the heat transfer from the gas stream to the material, since the thermal resistance of heat transfer due to the fins of the outer surface decreases in proportion to the finning coefficient (the ratio of the area of the fin surface to the area of a smooth surface before its fins). (A.P. Baskakov, B.V. Berg, O.K. Witt and others. Heat engineering. T34, Vol. 2, revised. - M.: Energoatomizdat, 1991, p. 101) The number of ribs can be any. Since the most advantageous shape of the rib (calculations by E. Schmidt; Mikheev MA, Mikheeva IM Fundamentals of heat transfer. M69, 2nd edition, stereotype.- M .: Energy, 1977, p. 307) is edge, limited by two parabolas, then in the link of the inventive chain runs an edge close to this form.

The implementation of the outer surface of each chain link with ribbing depending on the number of ribs allows to reduce the metal consumption of the chain, which reduces the cost of the chain, especially chains made of expensive heat-resistant steels.

The chain, having a reduced mass, being in the material, destroys it less, abrades, and the amount of dust carried out by the gas stream from the furnace decreases accordingly. The reduction of dust removal from the furnace leads to a decrease in heat loss with exhaust gases and fuel economy.

The weight of the suspended chains is approximately 75-110% of the weight of that part of the furnace body along the length of which they are suspended. (Lisienko V.G., Schelokov Y.M., Ladygichev M.G.

Rotary kilns: heat engineering, management and ecology: Reference publication: In 2 books. Book 1 / Ed. V.G. Lisienko. - M.: Heat engineer, 2004, p. 454). Due to the reduction in mass of the chain, the weight of the rotating part of the furnace is significantly reduced, which means that the load on the rollers, bandages and gears of the gearboxes will be less. Reducing the load will allow the furnace designs to be less strengthened, which will lead to a decrease in the metal consumption of the furnace as a whole, and hence its price.

With a finned surface of a link of the claimed chain, the sludge film adhering to it is easier to separate from the surface of the links, because in the relief of the film, which repeats the relief of the links, there are multidirectional forces of its breaking and separation from the links, which contributes to quick self-cleaning of the chains in front of the decarbonization zone and preservation of the particle size distribution of the material, coming from the chain zone, and does not increase the dust content of the gas stream.

The implementation of the inner surface of the cross section of the link with a radius equal to half the chain pitch, or the radius of the curved part of the chain step, increases the contact surface between the chain links, and due to the reduction of the load on the inner surface of the link reduces its wear.

The essence of the claimed utility model is illustrated by the drawings:

Figure 1 - shows a fragment of a section of a chain in the version with round

links;

Figure 2 - shows a fragment of a section of a chain in the embodiment with oval links;

Figure 3 - shows a cross section of a chain link.

A chain for a chain curtain of a rotary kiln, consisting of interconnected links 1 of any geometric shape, where the outer section surface of each link is made with ribbing 2, and the inner section surface of each link is made with radius r equal to half the chain pitch t / 2, or radius R of the curved portion of the chain pitch t.

The rib 2 is made in the form of ribs bounded by two parabolas, the number of ribs can be any.

The cross section of link 1 is made of any geometric shape.

The chain for the chain curtain of a rotary kiln is used as follows:

Chains are used as an internal heat exchanger. During the rotation of the furnace, some of the chains are in the gas stream, and the rest is immersed in the material. At the beginning of the chain zone, sludge adheres to chains in the gas stream. Chains in this part of the zone increase the contact surface of the sludge with hot gases, and as a result, heat transfer improves. When the sludge dries, it loses its plasticity and no longer sticks to the chain. From this moment, the heat is transferred to the material by the chains according to the regenerative principle: the chains are heated in the gas stream and, when immersed in the material, transfer heat to it. Along with this, the material receives heat from gases and lining.

The optimal design of the circuits should ensure effective heat transfer, be resistant to high temperatures, withstand high breaking load, maintain the particle size distribution of the material and not increase the dust content of the gas stream.

Claims (2)

1. A chain for a chain curtain of a rotary kiln, consisting of interconnected links of any geometric shape, where the inner end surface of each link is made curved, characterized in that the outer surface of the cross section of each link is made with ribbing, and the inner surface of the cross section of each link is made with a radius equal to half the chain pitch, or the radius of the curved part of the chain pitch. 2. The chain for a chain curtain of a rotary kiln according to claim 1, characterized in that the ribbing is made in the form of ribs bounded by two parabolas, the number of ribs can be any.