CN1044624C

CN1044624C - Improved hot galvahized tube inner-blowing technology

Info

Publication number: CN1044624C
Application number: CN96119078A
Authority: CN
Inventors: 杨运峰; 李青
Original assignee: BAOPING INVESTMENT DEVELOPMENT Co Ltd SHENZHEN
Priority date: 1996-05-23
Filing date: 1996-05-23
Publication date: 1999-08-11
Anticipated expiration: 2016-05-23
Also published as: CN1166534A

Abstract

The present invention discloses an improved inner-blowing technique for a hot galvanized tube. The present invention is characterized in that heated compressed air is used as an inner-blowing medium, and the compressed air which is offered by an air compressor is heated with the adoption of a drying brick bed, namely that the compressed air out of the compressor goes through tubes buried in the drying brick bed for heating, and then the compressed air is blown to the inner surface of the hot galvanized tube. The improved inner-blowing technique can enhance the quality of the galvanized layer of the tube, and the thickness of the galvanized layer tends to be uniform; zinc is saved so production cost is reduced, and meanwhile, the investment cost is reduced and energy is saved.

Description

The inner-blowing technology of hot dip galvanizing pipe

The present invention relates to the production technique of hot galvanized steel pipe, especially its inner-blowing technology.

Existing technique for producing hot galvanizing steel pipe flow process is as follows substantially: 1. rust cleaning is about to treat that galvanized steel pipe is soaked in for some time in the certain density acid solution, to remove the corrosion of steel pipe surfaces externally and internally; 2. clean, promptly the acid solution on the steel pipe is cleaned up with clear water; 3. be stained with soup, the steel pipe after being about to clean is immersed in certain hour in the zinc chloride solvent, allows solvent by reaction sticks on the tube wall with iron; 4. oven dry will be stained with the water molecules of the steel tube surface of soup and have been removed; 5. zinc-plated, soon the steel pipe after aforementioned operation is handled places the zinc liquid certain hour of certain temperature, zinc is plated on the surfaces externally and internally of steel pipe; 6. blow outward, promptly use the 3-5 kg/cm ²The pressurized air of pressure blows clean the entrapped zinc liquid and the floating thing of outer surface of steel tube; 7. blow in, use the 5-8 kg/cm ²The water vapor of pressure blows clean the entrapped zinc liquid and the floating thing of inner surface of tube; 8, cooling places cooling trough to be chilled to normal temperature the steel pipe that has plated zinc.

In the above-mentioned technical process, blow outward and in to blow be the twice critical process that directly influences pipe surfaces externally and internally quality.Wherein, blowing used pressurized air is outward provided by compressor, and because of pipe just comes out from zinc liquid, temperature descends few, and after the pressurized air after the compressed machine heating blew down, surface quality met the requirements substantially.But also owe the high outer quality of blowing that influences sometimes because of compressed-air actuated temperature.

Since in blow that the water vapor that is with heating carries out, have following many disadvantages: need to be equipped with one and overlap steam generating plant and auxiliary facility, increased cost of investment; Requirement, boiler house for the environmental safety aspect must cause pipeline to prolong, consume heat energy away from production plant; Blow in the pipe in the middle of producing that requirement remains on the 6-8 kg/cm to vapor pressure ²So boiler will ceaselessly burn at 24 hours keep-uping pressure, stopped production several hours even break down aborning, boiler also dare not reduce pressure, and pressure does not increase during product shy with strangers; The coal consumption amount is big, causes great energy loss; Because steam contains certain moisture, its role not only can not be removed foreign material sometimes, on the contrary in touching pipe the after-acceleration of entrapped zinc liquid solidifying of zinc liquid, make the increasing of inner surface of tube roughness, thickened the zinc layer, strengthened the zinc consumption, improved cost; Contain water temp in the steam and be lower than 230 ℃ of the temperature that requires of institute sometimes, touch and cause easily behind the zinc liquid and burst apart, cause plating leakage, product can't be come into operation.

The objective of the invention is: a kind of inner-blowing technology of hot dip galvanizing pipe is provided,, its thickness is tending towards evenly, save the zinc consumption, reduce production costs to improve the pipe quality of coating; Also reduce simultaneously cost of investment, save the energy.

Technical scheme of the present invention is: a kind of inner-blowing technology of hot dip galvanizing pipe, it is characterized in that passing by the pressurized air that compressor provides be embedded in oven dry in a heatable brick bed pipeline and heat, again the pressurized air of heating is blowed to the internal surface of hot dip galvanizing pipe, described compressed-air actuated Heating temperature is 230--280 ℃, and pressure is the 6--8 kg/cm ²

Aforesaid inner-blowing technology of the present invention, owing to adopted pressurized air to replace blowing medium in traditional water vapor conduct, moisture content reduces greatly in the medium, in when blowing, zinc liquid setting rate on the tube wall slows down, the thickness of zinc blows evenly easily on the tube wall, blows quality and yield rate in making and improves the consumption of also having saved zinc; Replace steam boiler with compressor and oven dry a heatable brick bed, facility investment is saved more than 70%, the while has also been saved artificial, has made things convenient for production management.

Below by drawings and Examples the present invention is described in further detail.

Fig. 1 is the plot plan of an exemplary embodiments of the present invention.

The embodiment of the invention as shown in Figure 1, outer air blowing source is by 3M ³Heating-type air compressor machine 5 provides, and pressure is the 3--5 kg/cm ²Interior air blowing source is by 6M ³Heating-type air compressor machine 6 provides; Pressure is the 6--8 kg/cm ²The compressed air temperature of two air compressor machines output is 150--180 ℃.

Oven dry a heatable brick bed 1 is closed device that be built into refractory brick, that have air inlet flue and gas shaft, and its used thermal source is introduced by flue 17 by the hot gas and the flame of zinc process furnace 2; The inside and outside pressurized air that blows usefulness is after the pipeline 8 and 7 by S shape further is heated to 230--280 ℃ in oven dry a heatable brick bed 1 respectively, interior blowing compressed air through interior air blowing narrow-necked earthen jar 10, in puff away pipeline 12 and interior blowing ring 14 blow hot dip galvanizing pipe on the roller-way 16 in blowing to, outer blowing compressed air is through outer air blowing narrow-necked earthen jar 9, puff away pipeline 11 and outer blowing ring 13 blows hot dip galvanizing pipe on the roller-way 15 outside blowing to outward.

Implementing when of the present invention, in blow control steam valve door and preferably adopt the fast-open type stopping valve.Compare with traditional general ball valve, adopt the fast-open type stopping valve, air can form bigger explosive power at tube interior when blowing in carrying out, and moment will manage interior residual, foreign material and be blown off.Compressed air line by the oven dry a heatable brick bed preferably adopts S shape layout to improve heats.The size of oven dry a heatable brick bed and the length of heating tube are advisable to guarantee that pressurized air is heated to 230--280 ℃.In the above embodiment of the present invention simultaneously will outside the air compressor machine pipeline that blows by original not heating, also make heating into, pipeline is equally by the oven dry a heatable brick bed, is unlikely to descend too greatly and influences finishing of blowing in the next procedure through outer tube temperature of blowing earlier like this.

Pressing the scheme of the foregoing description processed 4 fens--and 4 cun hot dip galvanizing pipes, average daily production can reach 50 tons.

Claims

1, a kind of inner-blowing technology of hot dip galvanizing pipe, it is characterized in that passing by the pressurized air that compressor provides be embedded in oven dry in a heatable brick bed pipeline and heat, again the pressurized air of heating is blowed to the internal surface of hot dip galvanizing pipe, described compressed-air actuated Heating temperature is 230-280 ℃, and pressure is the 6-8 kg/cm ²

2,, it is characterized in that blowing control steam valve door in described adopts the fast-open type stopping valve according to the inner-blowing technology of the hot dip galvanizing pipe of claim 1.

3,, it is characterized in that adopting S shape layout by the compressed air line of oven dry a heatable brick bed according to the inner-blowing technology of the hot dip galvanizing pipe of claim 1.

4,, it is characterized in that the used thermal source of described oven dry a heatable brick bed introduced by flue by the hot gas and the flame of zinc process furnace according to the inner-blowing technology of the hot dip galvanizing pipe of claim 1.