CN200996792Y - Low-thermal resistance cast-iron cooling wall - Google Patents

Abstract

A novel low-heat-resistance cooling wall of cast iron is provided, which is characterized in that the body of the cooling wall is of nodular cast iron or gray cast iron, the cooling-water channel in the cooling wall is made of pure copper pipes.

Description

Novel low thermal resistance cast-iron cooling wall

Technical field

Technical field under the utility model is the body of heater cooling technology of high temperature stoves such as blast furnace and other metallurgical furnaces, heating furnace, combustion furnace, relates to a kind of low thermal resistance cast-iron cooling wall of new construction.

Background technology

The body of heater of high temperature stoves such as blast furnace and other metallurgical furnaces, heating furnace, combustion furnace all needs cooling technology, and cooling wall (device) promptly is set in the furnace wall.The material of traditional cooling wall (device) mainly contains spheroidal graphite cast-iron, casting pig, mild steel and fine copper cooling wall, all cooling-water duct will be set in the cooling wall of any material (device).Except the fine copper cooling wall, the cooling-water duct in the cooling wall of other material all uses the seamless steel pipe of low-carbon steel material.

1. cast-iron cooling wall

Cast-iron cooling wall in order to prevent the carburizing to cooling water pipe, must be coated anti-carburization coating at the outer surface of seamless steel pipe on the manufacturing process of cooling wall in manufacture process, and then carries out the cast of foundry goods; Because of the difference of two kinds of material thermal coefficient of expansions, cooling water pipe and cooling wall body must leave the air gap simultaneously.Since the air gap between the coating between cooling water pipe and the cast iron and coating and cast iron (or claiming air cleft) thus existence reduced the heat transfer and the cooling effect of cooling wall significantly, accelerated the damage process of cooling wall.

2. cast steel cooling wall

Cast steel cooling wall is because its body material is a mild steel, therefore cooling water pipe can not removed the anti-carburization coating of low heat conduction by carburizing in manufacture process, simultaneously because cooling wall body material is identical with the cooling water pipe material, need not specially leave the expansion clearance, therefore improve the overall thermal conductivity energy of cooling wall.But the material of cooling water pipe still is a mild steel, and steel pipe inwall ratio is easier to generate incrustation scale.

3. cooling water pipe

Except the fine copper cooling wall, the cooling water pipe in the cooling wall all is the mild steel seamless pipe.The cooling medium that is used for cooling wall mainly is the circulation of open circuit cooling water, the circulation of preliminary treatment cooling water, soft water inclosed recirculated cooling water, pure water sealing and circulating.Cooling water quality is good, and is just slow at the scale velocity of cooling water pipe inwall.But no matter use which type of cooling medium inevitably will produce fouling at the cooling water pipe inwall.Use open circuit recirculated water to be: A3 steel＞20 steel＞brass＞fine copper＞stainless steel＞aluminium to the scale velocity of unlike material; Use the scale velocity of preliminary treatment recirculated water unlike material to be: 20 steel＞A3 steel＞aluminium＞fine copper＞brass＞stainless steel.The thermal conductivity factor of incrustation scale is 1.6～1.8W/mk, only is 1/24～1/30 of original material, and the cooling water pipe interior wall construction causes cooling water heat exchange amount to reduce significantly with the cooling wall body temperature rising significantly, finally quicken the damage process of cooling wall.

Summary of the invention

At above-mentioned three deficiencies of conventional art, the novel low thermal resistance cast-iron cooling wall that the purpose of this utility model provides a kind of new construction substitutes above cooling wall (device), and this new type cooling stave is made of spheroidal graphite cast-iron or casting pig; The cooling water pipe material is selected fine copper material seamless pipe, and therefore the cooling water pipe outer surface does not need to spray anti-carburization coating when making, and has eliminated the thermal resistance that anti-carburization coating brought; And the cooling duct material in the cooling wall is the pure copper tube of high thermal conductivity material, increased considerably the overall thermal conductivity energy of cooling wall, thereby be the efficient cooling wall of a kind of brand-new low thermal resistance, all can adopt this novel cast-iron cooling wall (device) to replace traditional cooling wall at blast-furnace shaft and other kiln all sites, prolong the life of the blast furnace and improve the blast furnace productivity effect.

The technical scheme of finishing the foregoing invention task is: novel low thermal resistance cast-iron cooling wall, it is characterized in that: cooling wall body material is the spheroidal graphite cast-iron or the casting pig of high-melting-point (〉=1200 ℃), and the cooling-water duct in the cooling wall is made of low melting point (1080 ℃) pure copper tube.

1. described cooling water pipe is the pure copper tube of impervious carbon, high thermal conductivity (340 kilocalories/meter time ℃), high-elongation (〉=30);

2. the gap between cooling wall body and the pure copper tube outer wall is less than 0.1mm;

3. described pure copper tube is selected the pure copper tube of 6～8mm wall thickness for use.

Because the molten iron temperature of spheroidal graphite cast-iron and casting pig is at 1300～1380 ℃, and 1083 ℃ of the fusing points of fine copper, if adopt traditional casting method, pure copper tube will water fashionable the thawing at molten iron, can't produce cooling wall of the present utility model.Key problem in technology will guarantee low-melting pure copper tube not by burn through and fusing when the cast cooling wall, and in order to enable those skilled in the art to implement structure of the present utility model, the utility model discloses the manufacturing process of this structure simultaneously:

The manufacture method of novel low thermal resistance cast-iron cooling wall, its step be,

It is fixing that the pure copper tube of typing is put into the sandbox that need make according to the cooling wall external form;

When pouring into a mould, the pure copper tube of being poured into a mould is carried out the cooling of inerting steam, cast molding with the molten iron of spheroidal graphite cast-iron or casting pig.

Above-described " pure copper tube is carried out the cooling of inerting steam " can adopt following method:

1. the molten iron heat was evenly distributed when cast gate was also noted that casting as rising head except considering the feeding effect;

2. at the chill of the arranged around some that is cast into copper pipe, reduce the wash away fusing effect of high temperature liquid iron to pure copper tube;

3. in casting process, the pure copper tube that is cast into is passed to low amounts of water, make it in the copper pipe that is heated by high temperature liquid iron, produce a large amount of heats of vapor absorption and reduce the resulting heat of copper pipes, reduce the temperature of copper pipe and prevent the copper pipe fusing;

According to the copper pipe cross section water yield is controlled at 0.5～2.0kg/min; The water yield that the application recommends is controlled at 0.8kg/min;

4. for all parts to the even cooling copper tube of steam of water flowing generation in the copper pipe, must feed inert gas in water flowing, one can prevent that steam from accumulating in pure copper tube, and two can prevent the oxidation of casting process high temperature to copper pipe;

The inert gas that the application recommends to adopt is a nitrogen; The flow velocity of inert gas is controlled at 8～15m/s.

Before the application, because the melting temperature of fine copper is lower than the temperature of spheroidal graphite cast-iron and casting pig molten iron, so the disclosed this structure of the application is unexistent in the prior art.The novel low thermal resistance cast-iron cooling wall that the utility model provides, the pure copper tube that is cast into impervious carbon, high thermal conductivity (340 kilocalories/meter time ℃), high-elongation (〉=30), slow fouling in cast iron quality is as the cooling water water pipe; Eliminated the thermal resistance that anti-carburization coating brings, thereby cooling water is increased the heat exchange efficiency of cooling wall body; Use its encrustation of fine copper cooling water pipe to slow down simultaneously, further improve the overall thermal conductivity energy of cast-iron cooling wall, prolong the life-span of cast-iron cooling wall.

Description of drawings

Fig. 1 is the cutaway view of the utility model structure;

Fig. 2 is the vertical view of the utility model structure;

Fig. 3 is sandbox and casting schematic diagram.

The specific embodiment

Embodiment 1: novel low thermal resistance cast-iron cooling wall,

Referring to Fig. 1, Fig. 2: cooling wall body 1 material is made of spheroidal graphite cast-iron or casting pig, and cooling-water duct in the cooling wall 2 is made of pure copper tube.Described pure copper tube is the pure copper tube that adopts impervious carbon, high thermal conductivity, high-elongation, slow fouling.Gap between cooling wall body and the pure copper tube outer wall is less than 0.1mm.Described pure copper tube is selected the pure copper tube of 6～8mm wall thickness for use.

Claims (3)

1, a kind of novel low thermal resistance cast-iron cooling wall is characterized in that, cooling wall body material is made of spheroidal graphite cast-iron or casting pig, and the cooling-water duct in the cooling wall is made of pure copper tube.

According to the described novel low thermal resistance cast-iron cooling wall of claim 1, it is characterized in that 2, the gap between described cooling wall body and the pure copper tube outer wall is less than 0.1mm.

3, according to claim 1 or 2 described novel low thermal resistance cast-iron cooling walls, it is characterized in that described pure copper tube is selected the pure copper tube of 6～8mm wall thickness for use.