SU840113A1 - Cooler of metallurgical sets - Google Patents

Description

The invention relates to heat exchange devices of metallurgical units.

Known two-layer refrigerator of metallurgical units with pipes filled in metal plates, through which ^{5 * * * *} coolant circulates. Tru-. they can be connected to the process water circuit or cooled according to the principle of evaporative cooling fl].

The disadvantages of refrigerators are: ¹⁰

a) the risk of large quantities of water entering the furnace during pipe failure;

b) the difficulty of finding failed refrigerators;

c) the need for the use of expansion joints and gas seals;

d) the complexity and reliability of the technology _and manufacturing.

A refrigerator is also known with end-closed tubes filled with liquid and placed at one end in a metal plate. The other end of such pipes is cooled by the water of the secondary circuit [2].

However, in known refrigerators, it becomes possible to discharge water into the secondary cooling zone and lock it there with steam.

The proposed design of the refrigerator provides for the organization of directional natural circulation of the coolant in the pipes closed at the ends, using unilateral heating of these pipes by the heat flow coming from the working space of the metallurgical unit.

The purpose of the invention is to increase the durability of the refrigerator.

The goal is achieved in that the plate in which the pipes are placed is made of a two-layer - Metal from the side of the working space (heat flow) and refractory from the side of the furnace casing. The plane of separation of these layers passes through the diametrical plane of the pipe.

s 840113

The metal layer of the plate is made, for example, of cast iron or other material having a sufficiently high thermal conductivity and heat resistance. The refractory layer is made of a plate nizkoteploprovodnogo (less than 5 kcal / m'ch - ^C) refractory material ⁵ such as refractory concrete.

The internal volume of the pipes is divided by a flat partition into two parts: heat-receiving and circulating. These five chas- ₁₀ are interconnected at the ends of pipes and -zapolneny coolant to a level allowing to have sufficient. condensation section, which is introduced into the refrigerator of the secondary cooling circuit.

In order to equalize the hydrodynamic resistance of the heat-absorbing and circulation cavities of the pipes, the ratio of their cross-sectional areas is unity about ₂ о or more due to the location of the partition relative to the diametrical plane of the pipe. Depending on the heat flux density, the flat partition in the pipe cavity is displaced with respect to its 25 diametrical plane by 0.1-0.3. Of the inner diameter towards the surface that does not absorb heat load.

The free ends of the tubes of the refrigerator closed at the ends go beyond the furnace casing and are introduced into the refrigerators of the secondary cooling circuit.

In FIG. 1 shows a refrigerator, a longitudinal section; in FIG. 2 - the same, cross-sectional view.

The refrigerator is a stove, which consists of a heat-conducting metal plate 1 and a non-heat-conducting refractory plate 2. Between the plates 1 and 2 there are closed pipes at the ends 3. The contact boundary between the metal sponge 1 and the refractory layer 2 passes along the diametrical plane of the pipes 3. Internal volume pipes 3, divided by a flat partition 4 into a heat-receiving cavity 5 and a circulation cavity 6.

Above the liquid level in cavities 5 and 6, there is a free cavity 7 for con-.θ 'vapor condensation.

The free ends of tubes 3 are placed in the refrigerator 8 and the combined collector 9 with nozzles 10 for supplying and discharging the cooling fluid ₅₅ secondary-cooling circuit.

The proposed refrigerator works as follows ..

The heat flux from the side of the working space enters through a metal heat-conducting plate I to the pipe surface 3 in contact with it.

The coolant in the heat of the receiving cavity 5 heats up, evaporates, and the steam-water mixture rises along the pipe wall 3 adjacent to the metal ppi't. The rise of the steam-water mixture in the cavity 5 causes a downward movement of fluid in the cavity 6.

The steam-water mixture from the cavity 5 enters the cavity 7, where separation, condensation of the vapor, and cooling of the liquid take place. Chilled fluid enters cavity 6.

Thus, in the closed at the ends of the pipes 3 of the refrigerator creates a directed natural circulation of the coolant.

Steam condensation and cooling of the liquid in the cavity 7 is carried out by the liquid circulating through the nozzles 10, the collector 9 and the refrigerators 8. The secondary circuit can be connected to a water or evaporative cooling system.

The low-heat conductive refractory plate 2 serves as a reliable heat insulator, limiting the heat flux from the metal plate 1, and provides heat only to the heat-absorbing surface of the pipes 3. The surface of the pipes 3 in contact with the refractory plate practically does not perceive the heat flux. Therefore, on the inner surface of the pipe 3 in the circulation cavity 6, the coolant does not boil. Each pipe 3 of the refrigerator has an autonomous cooling circuit. The increase in heat flow to any of the pipes 3 leads to automatic acceleration of the circulation of the coolant in a closed inner loop and increase heat transfer.

In case of damage to one of the pipes 3 of the refrigerator, the cooling rate of the metal layer I is somewhat reduced, but the refrigerator does not fail.

Coolant from the damaged pipe 3 exits in the form of steam and does not constitute a danger to the unit.

Thus, the refrigerator of the proposed design eliminates the possibility of water entering the working space of the unit, automatically responds to changes in heat loads on each pipe individually, is autonomous and not

affects the operation of other refrigerators, provides gas tightness at the places where pipes exit the furnace casing and complete operational safety, is technologically advanced to manufacture and when installed on an aggregate. ₅

The use of refrigerators of the proposed design can significantly increase the overhaul life of a metallurgical unit.

The proposed refrigerator may ₁₀

It has been used on metallurgical units, for example, blast furnaces, where rational cooling of the refractory masonry is necessary, or as a working surface facing directly into the working space of the furnace.

Claims (2)

This invention relates to heat exchangers for metallurgical aggregates. A two-layer refrigerator of metalworking units with pipes poured into metal plates is known, which coolants are filled with. The pipes can be connected to the technical water circuit or cooled according to the principle of evaporative cooling. The disadvantages of refrigerators are: a) the danger of large amounts of water entering the kiln when pipes break; b) the complexity. the search for out-of-process refrigerators; c) the need to use thermal expansion joints and gas seals; d) the complexity and reliability of manufacturing technology. Also known refrigerator with closed at the ends of the tubes filled with liquid and placed at the end of the metal plate. The other end of such tubes is cooled with water from the secondary circuit I2j. However, in known refrigerators, it is possible to discharge water into the secondary cooling zone and lock it there with steam. The proposed design of the refrigerator uses the organization of directed natural circulation of coolant in the pipes closed at the ends using the one-sided heating of these pipes by heat flux coming from the working space of the metallurgical unit. 11el of the invention - improving the durability of the refrigerator. The goal is achieved by the fact that the plate in which the pipes are made is double-layered - metal from the side of the working space (heat flow) and refractory from the side of the furnace casing. The plane of separation of these layers passes through the diametral plane of the pipe. 84 The metal layer is made, for example, of cast iron or other material having a sufficiently high tensile strength and high resistance. The refractory layer of the plate is filled with low heat conductive (less than 5 kcal / m h) refractory material, for example, refractory concrete. The internal volume of the pipes is divided by a flat partition into two parts: a heat-receiving and circulating one. These parts communicate with each other at the ends of the pipe and are filled with coolant to a level that allows them to have sufficient. a condensation section that injects into the refrigerator of the secondary cooling circuit. In order to equalize the hydrodynamic resistance of the heat-receiving and circulating cavities of the pipes, the ratio of the areas of their cross sections is equal to one or more in terms of the location of the partition relative to the diametral length of the pipe. Depending on the density of the heat flow, the flat partition in the cavity of the pipe is offset relative to its diametrical plane by 0.1-0.3. Of the internal diameter towards the surface that does not absorb the heat load. The free ends of the cooler tubes closed at the ends go outside the furnace casing and are introduced into the cooling circuit of the secondary circuit cooled. FIG. I shows the refrigerator, about the longitudinal section; in fig. 2 - the same cross section. The refrigerator is a plate which consists of a heat-conducting metal plate I and a non-heat-conducting refractory plate 2. Plates 3 are closed along the ends of plates I and 2. The contact boundary between the metal layer I and the refractory layer passes along the diametral plane of the pipes 3. Internal volume of pipes 3 , is divided by a planar partition 4 into a heat-receiving cavity 5 and a circulating cavity 6. Above the fluid level in the cavities 5 and 6, there is a free cavity 7 for KO steam vaporization. The free ends of the pipes 3 are placed in refrigerators 8, combined by manifolds 9, with tO connections for supplying and discharging coolant to the secondary cooling circuit. The proposed refrigerator works as follows. The heat flow from the side of the working space flows through the metal heat-conducting plate I to the surface of the pipes 3 contacting with it. The cooling liquid in the heat-receiving cavity 5 is heated, evaporated, and the steam pipe rises to the mixture along the wall of the pipe 3 adjacent to the metal plate I. The steam mixture in the cavity 5 causes a downward movement of the liquid in cavity 6. A steam line to the mixture from cavity 5 enters the cavity 7, where separation, condensation of steam, and cooling of the liquid take place. The cooled liquid enters the cavity 6. Thus, in the closed at the ends of the pipes 3 of the refrigerator, a directional natural circulation of the cooling liquid is created. The vapor condensation and cooling of the liquid in the cavity 7 is carried out by the liquid circulating through the pipes Yu, the collector 9 and the refrigerators 8. The secondary circuit can be connected to the water or evaporative cooling system. The low heat-conducting refractory plate 2 serves as a reliable heat insulator limiting the heat flux from the metal plate 1 and provides heat only to the heat-receiving surface of the pipes 3. The surface of the pipes 3, which is in contact with the refractory plate, hardly perceives the heat flux. Therefore, the cooling liquid does not boil on the inner surface of the pipe 3 in the circulation cavity 6. Each cooler pipe 3 has an independent cooling circuit. The increase in heat flow to any of the pipes 3 leads to an automatic acceleration of the circulation of coolant through a closed internal circuit and increased heat transfer. In the event of damage to one of the pipes 3 of the refrigerator, the cooling rate of the metal layer I decreases somewhat, but the refrigerator does not deteriorate. The cooling liquid from the damaged pipe 3 comes out in the form of vapor and does not represent a danger to the unit. Thus, the refrigerator of the proposed design eliminates the possibility of water entering the working space of the unit, automatically reacts to changes in heat loads on each individual pipe, is autonomous and does not affect the operation of other refrigerators, ensures gas density in the exhaust pipe and the furnace shell and full safety of operation, adaptable to fabrication and installation on the machine. The use of refrigerators of the proposed design allows one to increase the turnaround time of the metallurgical unit. The proposed cooler can be applied on metallurgical aggregates, for example blast furnaces, where rational cooling is necessary for heat-resistant masonry, or as a working surface facing directly into the working space of the furnace. Claims I. A refrigerator of metallurgical units consisting of a two-layer plate and heat pipes with closed ends and an internal partition, one end of which is placed in the plate, and the other in a cooled case, characterized in that The two-layer plate is made of highly heat-conducting material from the side of the working space and from the side of the casing of the metallurgical unit, and the boundary of the layers passes along the diametral plane of the cooling tubes, parallel to th plane plate. 2. Refrigerator according to claim I, about tl and h and y and the fact that the internal partition in the cooling tube is mixed from the diametrical plane of the pipes in the direction of the low heat-conducting layer of the plate on the value of OD-O, 3 internal diameter of the pipe. Sources of information forma tion taken into account during expection 1. USSR author's certificate in application no. 2043651/02, cl. from 21 to 7/10, 15.O6.1974. 2. USSR author's certificate N9 388025, cl. From 21 to 7 / 1O, 07.15.71 .. / 91 6 1