CA1247992A - Process and apparatus for deoxidation of shells for the production of pipes - Google Patents
Process and apparatus for deoxidation of shells for the production of pipesInfo
- Publication number
- CA1247992A CA1247992A CA000487228A CA487228A CA1247992A CA 1247992 A CA1247992 A CA 1247992A CA 000487228 A CA000487228 A CA 000487228A CA 487228 A CA487228 A CA 487228A CA 1247992 A CA1247992 A CA 1247992A
- Authority
- CA
- Canada
- Prior art keywords
- deoxidation
- agent
- shell
- gas
- deoxidation agent
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000000034 method Methods 0.000 title claims abstract description 43
- 230000008569 process Effects 0.000 title claims abstract description 42
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 7
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 75
- 239000000203 mixture Substances 0.000 claims abstract description 21
- 238000005096 rolling process Methods 0.000 claims abstract description 16
- 230000033001 locomotion Effects 0.000 claims abstract description 8
- 239000008240 homogeneous mixture Substances 0.000 claims abstract description 7
- 239000007789 gas Substances 0.000 claims description 38
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 8
- 239000011796 hollow space material Substances 0.000 claims description 6
- 239000011261 inert gas Substances 0.000 claims description 5
- 229910052757 nitrogen Inorganic materials 0.000 claims description 4
- 239000000843 powder Substances 0.000 claims description 4
- 239000008187 granular material Substances 0.000 claims description 3
- 238000009826 distribution Methods 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000033764 rhythmic process Effects 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 150000007513 acids Chemical class 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 239000010410 layer Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 230000001050 lubricating effect Effects 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 238000010405 reoxidation reaction Methods 0.000 description 1
- 239000011833 salt mixture Substances 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000005204 segregation Methods 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B45/00—Devices for surface or other treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills
- B21B45/04—Devices for surface or other treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills for de-scaling, e.g. by brushing
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
- C23G3/00—Apparatus for cleaning or pickling metallic material
- C23G3/04—Apparatus for cleaning or pickling metallic material for cleaning pipes
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
- Metal Rolling (AREA)
- Solid-Sorbent Or Filter-Aiding Compositions (AREA)
Abstract
PROCESS AND APPARATUS FOR DEOXIDATION OF SHELLS
FOR THE PRODUCTION OF PIPES
ABSTRACT OF THE DISCLOSURE
A process is disclosed for the processing of deoxidation agents, especially those used for the deoxidation of shells heated to rolling temperature for the production of pipes. The deoxidation agent is fed by volumetric or gravimetric dosing into a pressure container. From 5 up to 100 g of deoxidation agent is present per square meter (m2) of the inside wall surface of the shell. Compressed gas is inserted into the pressure container so that a ratio of from 50 to 750 standard liters of gas per kilogram of deoxidation agent is attained. The gas and the deoxidation agent are guided as a homogenous mixture through a transport line to a nozzle of special design, which guides the homogenous mixture in a circular, turbulent, laminary or pulsating movement in the shell, which has been heated to rolling temperature. In this manner, the deoxidation agent is applied to the walls of the shell. Apparatus is also disclosed for processing deoxidation agents according to the above process. The apparatus has a supply container for the deoxidation agent, and a volumetric or gravimetric dosing arrangement attached to it which empties into a pressure container. The pressure container has an inlet for pressurized gas and an outlet for the gas-deoxidation-agent mixture. The outlet is controlled by valve. The apparatus also has a conveying line, while a delivery nozzle, located on the end of the conveying line, is used for the gas-deoxidation-agent mixture.
FOR THE PRODUCTION OF PIPES
ABSTRACT OF THE DISCLOSURE
A process is disclosed for the processing of deoxidation agents, especially those used for the deoxidation of shells heated to rolling temperature for the production of pipes. The deoxidation agent is fed by volumetric or gravimetric dosing into a pressure container. From 5 up to 100 g of deoxidation agent is present per square meter (m2) of the inside wall surface of the shell. Compressed gas is inserted into the pressure container so that a ratio of from 50 to 750 standard liters of gas per kilogram of deoxidation agent is attained. The gas and the deoxidation agent are guided as a homogenous mixture through a transport line to a nozzle of special design, which guides the homogenous mixture in a circular, turbulent, laminary or pulsating movement in the shell, which has been heated to rolling temperature. In this manner, the deoxidation agent is applied to the walls of the shell. Apparatus is also disclosed for processing deoxidation agents according to the above process. The apparatus has a supply container for the deoxidation agent, and a volumetric or gravimetric dosing arrangement attached to it which empties into a pressure container. The pressure container has an inlet for pressurized gas and an outlet for the gas-deoxidation-agent mixture. The outlet is controlled by valve. The apparatus also has a conveying line, while a delivery nozzle, located on the end of the conveying line, is used for the gas-deoxidation-agent mixture.
Description
~ 7~3~ LP 1337 The invention relates to a process and an app~ratus fcr the deoxidation of hollow bodies such as shells, hollow blocks or pipes.
I-t is known to deoxidize metal surfaces and especially steel surfaces prior to transformation. One method of deoxidizing involves surface treatment with acids, acid mixtures, alkalines or salt mixtures. For example, in the case of the processing of shells made of iron and especially of steel, such as, hollow blocks or pipes and especially of shells for seamless pipes in installations such as push-bench plants, Assel mills, plug mills, hot pilger mills, continuous mills, multiple pipe mills, up-setters, etc., the inside of the shell, the hollow block or the pipe must be deoxidized prior *o introduction of the mandrel bar at a temperature in the range oE the rolling tempera~ure, that is, around 1000 to 1300C. As a result of the complexity of the operation in rolling mills of the type mentioned, it has not been possible hitherto to achieve a complete deoxidation in an economic manner. Sometimes only such " j,~
~, 3~2 ~ 2 - LP 1337 short time intervals as about one second are available for the application of the deoxidizinq aqent.
The proposal had already been made to descale shells by introducing descaling agents, with the help of a compressed gas, in a circular motion at one end of the shell into the inside of the shell, which has been heated to rolling temperature, and to remove the residual mixture at the other end of the shell by suction~ Such process has the disadvantage of requiring great quantities of gas and descaling agents. For economic reasons, one must use air as the gas. But, as a rule, the air acts oxidatively, especially when used in such large quantities, and also seriously tends to cool the inside of the shell. Furthermore, the removal by suction and filtering of the residual mixture of gas and salts is not without problems.
~" _ An object of the invention is to provide an apparatus and a process which allows, in the course of the operation o a rolling mill, the continuous conducting of a deoxidation process as completely as possible. Another object of the invention is to efect the above object with a minimal amount of equipment with an adapted quantity of deoxidation agent.
The invention provides a process for the processing of deoxida-tion agents, especially Eor tha deoxidation of shells heated to rolling temperature for the production of pipes. The deoxidation agent is fed by volumetric or gravimetric dosing into a pressure container. From 5 up to 100 g of deoxidation agent is present per square meter (m2) of the inside wall surface of -the shell. Com-pressed gas is fed into the pressure container so that a ratio of from 50 to 750 standard liters of gas per kilogram of deoxidation agent is attained. The gas and the deoxida-tion agent are guided as a homogenous mixture through a transport line to a delivery arrangement, which guides the homogenous mixture in a circular, turbulent, laminary or pulsating movement in or onto the shell, which has been hea-ted to rolling temperature. In this manner, the deoxida-tion agent is applied to the walls of the shell.
The process of the invention is carried out in such a way that the deoxidation agent is used effectively in a dry form as a powder having an average grain size o~ from 50 to 1000 micrometers or as a granulate having an average grain size of from 0.5 to 4 rnm in a supply container. As a rule, the deoxidation agent is fed into a dosing apparatus by gravity, if necessary with the support, for example, of a shaker, by means of a rotating stirrer or by blowing in air, in order to avoid the formation of a bridge of the powder.
The silo container can be developed possibly as a pressure container and the material is then delivered by the action of pressure.
The invention also provides an apparatus for the processing o~ deoxidation agents according to the process o~
the invention. The apparatus has a supply container for the deoxidation agent, and a volumetric or gravime-tric dosing arrangement attached to it which empties into a pressure container. The pressure container has an inlet for the pressure gas and an outlet for the gas-deoxidation-agent mixture. The outlet is controlled by an opening valve. The apparatus includes a conveying line and delivery apparatus, located on the end of -the conveying line, is used for the gas-deoxidation-agent rnixture.
As the dosing apparatus, known dosing appara-tuses such as dosing scales, dosing worms, dosing spirals, oscillating chargers or a dosing~ribbon can be used. The dosing is _ 5 _ ~ ~ ~7~
carried out gravimetrically or volumetrically. Effectively volumetric dosing is achieved; preferably a worm dosing apparatus is used.
An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawing, in which:
The Figure is a partially-cut away perspective view of a preferred embodiment of the apparatus of the invention.
To effect the dosing, the deoxidation agent is first inserted into a pressure container. The pressure container is placed under pressure by means of a gasO Sui-table gases include air, nitrogen CO2, an inert gas or a mixture of at least two of such gases.
From 5 to 100 g of deoxidation agents are used per m of the inside surface or inside wall of the shell. Effectively from 10 to 60 g, advan-tageously from 25 to 50 g, of deoxidation agent are used per m2 Of inside wall surface.
The volume of gas is from 50 to 750 standard liters per kilogram of deoxidation agen-t. In an effective embodiment, from 100 to 500 standard liters, preferably from 100 to 250 - 6 ~ LP 1337 standard liters, of gas are used per kilogram of deoxidation agent. The pressure in the pressure container is from 2 to 20 bar and preferably is from 2 to 10 bar.
After completion of the pressure loading of the pressure container, the ~eoxidation agent can be introduced into the working sequence of the rolling mill. For this purpose, a conveying lin~ has been provided which leads from the pressure container to a delivery apparatus. The delivery apparatus can be, for exampla, a simple pipe opening, a delivery cone, possibly equipped with a spiral or with a diffuser, and various types of nozzles~
In order to distribute and apply the deoxidation aqent evenly in the hollow space of the shell, a circular, laminary, turbulent or pulsating flow of the gas~deoxidation-agent mixture is normally used - generally a circular or turbulent flow is desired. Circular movement means that the mixture moves while forming a spiral-shaped movement right through the opening of the shell. Laminar flow means that the mixture flows through the opening of the workpiece in an essentially even movement, whereas with t~~rbulent flow an eddy effect of the flowing medium is sought. The pulsating flow circumscribes a process according to which the mixture is guided in several pressure surges through the opening of the shell.
The delivery apparatus can be a-t-tached in the area of the end of the shell, centrically as well as eccentrically in relation to the opening of the shell.
However, the delivery apparatus can be moved into the inside of the shell or the delivery apparatus can be guided through the opening of the shell during the delivery of the mixture.
During the use of the deoxidation agent, the shell as a rule has a rolling temperature of about 1000 to about 1300 C. Temperature changes may still occur between the deoxidation process and the firs~ rolling process.
The process according to the invention is carried out with an apparatus which is shown in the Figure, which apparatus includes a supply container 1 for the deoxidation agent, and a volumetric or gravimetric dosing arrangement 2, which empties into a pressure container 3 and which i5 connected to the supply container 1. The pressure container 3 is equipped with a compressed gas feeder ~ and an outlet 5 for the gas-deoxidation-agent mixture. Outlet 5 is controlled by means of a valve 6, whereby after the opening of -the valve 6, the yas-deoxi~a-tion-agen-t mix-ture is guided through a conveying line 7 to a delivery apparatus 8. Delivery appara-tus 8 at - 8 - I,P 1337 the same time functions as a distribution arrangement and of guaranteeing an even, all-around delivery.
A further, additional characteristic of pressure container 3 is the formation or configuration of outlet 5. 1'he latter must ensure that the material is moved out without leaving a residue and without segregation during the operating rhythm. As a technical measure, this can be achieved, for example, by means of a pressure container having walls which incline very steeply in the direction of outlet 5 and/or by a cone in th~ area of outlet 5.
Additional embodiments involve the preheating of the gas and/or of the descaling agent either in front of or within pressure container 3 or in conveying line 7.
As a result of the relatively small quantities of deoxidation agent and gas that are used, such preheating is easily achieved.
By adaption of the dosing apparatus and of the delivery apparatus of the invention, the deoxidation agent can be processed in the same manner in a liquid form as a solution, suspension or melt.
Customarily used and known types of construction can be used as valves and control means for dosing apparatus 9 and 10, compressed gas delivery 11 and outlet 6. The control can be accomplished, for example, mechanically, hydraulically, pneumatically or electromagnetically, whereby a control adapted to the operating rhythm of the rolling mechanism and the work sequence can be performed manually mechanically or electronically.
Furthermore, in the Figure, a shell, hollow block or pipe 12 and the hollow space designated as inside space 13 of shell 12 are shown.
By using the process according to the invention, one can successfully distribute the deoxidation agent in an even distribution without possible segreqation in the inside space of the shell, whereby the present layer of scale is modified or ch~mically converted. As a result of the use of the deoxidation agent, one usually obtainc not only an even and well adhering, thin surface layer, but the products formed on the inside surface of the workpiece usually have non-abrasive or even lubricating characteristics.
As a result of the use of small quantities of gas as compared to the known descaling processes, in the case of the use of air as a pressure gas, only relatively small quantities of oxygen come ~nto contact with the shell (heated to rolling temperature), which results in a considerably decreas~ ~nrmation of new oxidation products. In the case of the use o small quan-tities of qas it mav also he economically justifiable to use inert gases, such as nitrogen or inert gases. A reoxidation can thus be avoided.
As compared to the known processes for descaling, smaller or relatively small quantities of deoxidation agent are used per surface unit.
As a result of the small quantities of gas and deoxidizing agent use~ in the process of the invention, the previously proposed removal of the descaling gas mixture by suction becomes superfluous. A flashback of the mixture from the opening of the shell, as is easily possible in the case of the processes which are not conducted according to the invention, for example, by a momentary strong heating up, does not occur at all or, at most, in a nondisturbing manner. Whenever, according to the process of the invention, the gas and/or the deoxida-tion agent are preheated, these problems can be ignored altogether. Furthermore, the chosen flow pattern causes an extremely homogenous distribution of the cleoxida~ion agent on the inner surface of the shell so that no excessive amount of deoxidatiQn agent is needed for the process. Such an excessive amount would have to be separated again or 3~ 32 counted as an economic loss.
By way of summary, the invention involves a process for the processing of deoxidation agents and especially for the deoxidation of shells for the production of a pipe heated to a rolling temperature of from lO00~ to 1300 C. by the application of a predetermined quantity of deoxidizing agent by means of a predetermined quantity of gas as a homogenous mixture into the inside walls, for example, of a shell for the production of a seamless pipe.
The invention also involves an apparatus which includes a supply container and a dosing arrangement for the deoxidation agent. There is a pressure container which has a gas supply, an inlet for the deoxidizing agent and an outlet for the gas-deoxidation-agent mixture. The apparatus fur-ther has a conveying line as well as a delivery apparatu~.
:' `:
I-t is known to deoxidize metal surfaces and especially steel surfaces prior to transformation. One method of deoxidizing involves surface treatment with acids, acid mixtures, alkalines or salt mixtures. For example, in the case of the processing of shells made of iron and especially of steel, such as, hollow blocks or pipes and especially of shells for seamless pipes in installations such as push-bench plants, Assel mills, plug mills, hot pilger mills, continuous mills, multiple pipe mills, up-setters, etc., the inside of the shell, the hollow block or the pipe must be deoxidized prior *o introduction of the mandrel bar at a temperature in the range oE the rolling tempera~ure, that is, around 1000 to 1300C. As a result of the complexity of the operation in rolling mills of the type mentioned, it has not been possible hitherto to achieve a complete deoxidation in an economic manner. Sometimes only such " j,~
~, 3~2 ~ 2 - LP 1337 short time intervals as about one second are available for the application of the deoxidizinq aqent.
The proposal had already been made to descale shells by introducing descaling agents, with the help of a compressed gas, in a circular motion at one end of the shell into the inside of the shell, which has been heated to rolling temperature, and to remove the residual mixture at the other end of the shell by suction~ Such process has the disadvantage of requiring great quantities of gas and descaling agents. For economic reasons, one must use air as the gas. But, as a rule, the air acts oxidatively, especially when used in such large quantities, and also seriously tends to cool the inside of the shell. Furthermore, the removal by suction and filtering of the residual mixture of gas and salts is not without problems.
~" _ An object of the invention is to provide an apparatus and a process which allows, in the course of the operation o a rolling mill, the continuous conducting of a deoxidation process as completely as possible. Another object of the invention is to efect the above object with a minimal amount of equipment with an adapted quantity of deoxidation agent.
The invention provides a process for the processing of deoxida-tion agents, especially Eor tha deoxidation of shells heated to rolling temperature for the production of pipes. The deoxidation agent is fed by volumetric or gravimetric dosing into a pressure container. From 5 up to 100 g of deoxidation agent is present per square meter (m2) of the inside wall surface of -the shell. Com-pressed gas is fed into the pressure container so that a ratio of from 50 to 750 standard liters of gas per kilogram of deoxidation agent is attained. The gas and the deoxida-tion agent are guided as a homogenous mixture through a transport line to a delivery arrangement, which guides the homogenous mixture in a circular, turbulent, laminary or pulsating movement in or onto the shell, which has been hea-ted to rolling temperature. In this manner, the deoxida-tion agent is applied to the walls of the shell.
The process of the invention is carried out in such a way that the deoxidation agent is used effectively in a dry form as a powder having an average grain size o~ from 50 to 1000 micrometers or as a granulate having an average grain size of from 0.5 to 4 rnm in a supply container. As a rule, the deoxidation agent is fed into a dosing apparatus by gravity, if necessary with the support, for example, of a shaker, by means of a rotating stirrer or by blowing in air, in order to avoid the formation of a bridge of the powder.
The silo container can be developed possibly as a pressure container and the material is then delivered by the action of pressure.
The invention also provides an apparatus for the processing o~ deoxidation agents according to the process o~
the invention. The apparatus has a supply container for the deoxidation agent, and a volumetric or gravime-tric dosing arrangement attached to it which empties into a pressure container. The pressure container has an inlet for the pressure gas and an outlet for the gas-deoxidation-agent mixture. The outlet is controlled by an opening valve. The apparatus includes a conveying line and delivery apparatus, located on the end of -the conveying line, is used for the gas-deoxidation-agent rnixture.
As the dosing apparatus, known dosing appara-tuses such as dosing scales, dosing worms, dosing spirals, oscillating chargers or a dosing~ribbon can be used. The dosing is _ 5 _ ~ ~ ~7~
carried out gravimetrically or volumetrically. Effectively volumetric dosing is achieved; preferably a worm dosing apparatus is used.
An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawing, in which:
The Figure is a partially-cut away perspective view of a preferred embodiment of the apparatus of the invention.
To effect the dosing, the deoxidation agent is first inserted into a pressure container. The pressure container is placed under pressure by means of a gasO Sui-table gases include air, nitrogen CO2, an inert gas or a mixture of at least two of such gases.
From 5 to 100 g of deoxidation agents are used per m of the inside surface or inside wall of the shell. Effectively from 10 to 60 g, advan-tageously from 25 to 50 g, of deoxidation agent are used per m2 Of inside wall surface.
The volume of gas is from 50 to 750 standard liters per kilogram of deoxidation agen-t. In an effective embodiment, from 100 to 500 standard liters, preferably from 100 to 250 - 6 ~ LP 1337 standard liters, of gas are used per kilogram of deoxidation agent. The pressure in the pressure container is from 2 to 20 bar and preferably is from 2 to 10 bar.
After completion of the pressure loading of the pressure container, the ~eoxidation agent can be introduced into the working sequence of the rolling mill. For this purpose, a conveying lin~ has been provided which leads from the pressure container to a delivery apparatus. The delivery apparatus can be, for exampla, a simple pipe opening, a delivery cone, possibly equipped with a spiral or with a diffuser, and various types of nozzles~
In order to distribute and apply the deoxidation aqent evenly in the hollow space of the shell, a circular, laminary, turbulent or pulsating flow of the gas~deoxidation-agent mixture is normally used - generally a circular or turbulent flow is desired. Circular movement means that the mixture moves while forming a spiral-shaped movement right through the opening of the shell. Laminar flow means that the mixture flows through the opening of the workpiece in an essentially even movement, whereas with t~~rbulent flow an eddy effect of the flowing medium is sought. The pulsating flow circumscribes a process according to which the mixture is guided in several pressure surges through the opening of the shell.
The delivery apparatus can be a-t-tached in the area of the end of the shell, centrically as well as eccentrically in relation to the opening of the shell.
However, the delivery apparatus can be moved into the inside of the shell or the delivery apparatus can be guided through the opening of the shell during the delivery of the mixture.
During the use of the deoxidation agent, the shell as a rule has a rolling temperature of about 1000 to about 1300 C. Temperature changes may still occur between the deoxidation process and the firs~ rolling process.
The process according to the invention is carried out with an apparatus which is shown in the Figure, which apparatus includes a supply container 1 for the deoxidation agent, and a volumetric or gravimetric dosing arrangement 2, which empties into a pressure container 3 and which i5 connected to the supply container 1. The pressure container 3 is equipped with a compressed gas feeder ~ and an outlet 5 for the gas-deoxidation-agent mixture. Outlet 5 is controlled by means of a valve 6, whereby after the opening of -the valve 6, the yas-deoxi~a-tion-agen-t mix-ture is guided through a conveying line 7 to a delivery apparatus 8. Delivery appara-tus 8 at - 8 - I,P 1337 the same time functions as a distribution arrangement and of guaranteeing an even, all-around delivery.
A further, additional characteristic of pressure container 3 is the formation or configuration of outlet 5. 1'he latter must ensure that the material is moved out without leaving a residue and without segregation during the operating rhythm. As a technical measure, this can be achieved, for example, by means of a pressure container having walls which incline very steeply in the direction of outlet 5 and/or by a cone in th~ area of outlet 5.
Additional embodiments involve the preheating of the gas and/or of the descaling agent either in front of or within pressure container 3 or in conveying line 7.
As a result of the relatively small quantities of deoxidation agent and gas that are used, such preheating is easily achieved.
By adaption of the dosing apparatus and of the delivery apparatus of the invention, the deoxidation agent can be processed in the same manner in a liquid form as a solution, suspension or melt.
Customarily used and known types of construction can be used as valves and control means for dosing apparatus 9 and 10, compressed gas delivery 11 and outlet 6. The control can be accomplished, for example, mechanically, hydraulically, pneumatically or electromagnetically, whereby a control adapted to the operating rhythm of the rolling mechanism and the work sequence can be performed manually mechanically or electronically.
Furthermore, in the Figure, a shell, hollow block or pipe 12 and the hollow space designated as inside space 13 of shell 12 are shown.
By using the process according to the invention, one can successfully distribute the deoxidation agent in an even distribution without possible segreqation in the inside space of the shell, whereby the present layer of scale is modified or ch~mically converted. As a result of the use of the deoxidation agent, one usually obtainc not only an even and well adhering, thin surface layer, but the products formed on the inside surface of the workpiece usually have non-abrasive or even lubricating characteristics.
As a result of the use of small quantities of gas as compared to the known descaling processes, in the case of the use of air as a pressure gas, only relatively small quantities of oxygen come ~nto contact with the shell (heated to rolling temperature), which results in a considerably decreas~ ~nrmation of new oxidation products. In the case of the use o small quan-tities of qas it mav also he economically justifiable to use inert gases, such as nitrogen or inert gases. A reoxidation can thus be avoided.
As compared to the known processes for descaling, smaller or relatively small quantities of deoxidation agent are used per surface unit.
As a result of the small quantities of gas and deoxidizing agent use~ in the process of the invention, the previously proposed removal of the descaling gas mixture by suction becomes superfluous. A flashback of the mixture from the opening of the shell, as is easily possible in the case of the processes which are not conducted according to the invention, for example, by a momentary strong heating up, does not occur at all or, at most, in a nondisturbing manner. Whenever, according to the process of the invention, the gas and/or the deoxida-tion agent are preheated, these problems can be ignored altogether. Furthermore, the chosen flow pattern causes an extremely homogenous distribution of the cleoxida~ion agent on the inner surface of the shell so that no excessive amount of deoxidatiQn agent is needed for the process. Such an excessive amount would have to be separated again or 3~ 32 counted as an economic loss.
By way of summary, the invention involves a process for the processing of deoxidation agents and especially for the deoxidation of shells for the production of a pipe heated to a rolling temperature of from lO00~ to 1300 C. by the application of a predetermined quantity of deoxidizing agent by means of a predetermined quantity of gas as a homogenous mixture into the inside walls, for example, of a shell for the production of a seamless pipe.
The invention also involves an apparatus which includes a supply container and a dosing arrangement for the deoxidation agent. There is a pressure container which has a gas supply, an inlet for the deoxidizing agent and an outlet for the gas-deoxidation-agent mixture. The apparatus fur-ther has a conveying line as well as a delivery apparatu~.
:' `:
Claims (23)
1. A process for processing a deoxidation agent, comprising feeding the deoxidation agent by volumetric or gravimetric dosing into a pressure container with from 5 up to 100 g of the deoxidation agent being present per square meter of the inside wall surface of a shell to be deoxidized, feeding compressed gas into the pressure container so that a ratio of from 50 to 750 standard liters of gas per kilogram of deoxidation agent is attained, the gas and the deoxidation agent being guided as a homogenous mixture through a trans-porting line to a delivery arrangement, which guides the homogenous mixture in a circular, turbulent, laminary move-ment or circular, turbulent, pulsating movement in or onto the shell, which has been heated to rolling temperature, whereby the deoxidation agent is applied to the walls of the shell.
2. A process as claimed in claim 1, wherein the deoxidation agent is used for a shell heated to rolling temperature for the production of pipes.
3. A process as claimed in claim 1, wherein the deoxidation agent is dosed volumetrically.
4. A process as claimed in claim 3, wherein from 10 to 60 g of deoxidation agent is used per square meter of the inside wall surface of the shell and wherein from 100 to 500 standard liters of gas is used per kilogram of deoxidation agent.
5. A process as claimed in claim 3, wherein from 25 to 50 g of deoxidation agent is used per square meter of the inside wall surface of the shell and wherein from 100 to 250 standard liters of gas is used per kilogram of corroding agent.
6. A process as claimed in claim 4, wherein the delivery arrangement, during the application of the deoxida-tion agent, is guided into the hollow space of the shell through the opening of such hollow space.
7. A process as claimed in claim 4, wherein the deoxidation agent is guided through a delivery arrangement located in the area of the end of a shell, into the shell and is applied to the inside wall of the shell.
8. A process as claimed in claim 7, wherein the gas is air, nitrogen, CO2, an inert gas or a mixture of at least two such gases.
9. A process as claimed in claim 8, wherein the deoxidation agent is used in dry form as a powder having an average grain size of from 50 to 1000 micrometers or as a granulate having an average grain size of from 0.5 to 4 mm.
10. A process as claimed in claim 9, wherein the pressure container is acted upon with compressed gas so that the pressure therein is from 2 to 20 bars.
11. A process as claimed in claim 9, wherein the pressure container is acted upon with compressed gas so that the pressure therein is from 2 to 10 bars.
12. A process as claimed in claim 11, wherein the deoxidation agent is used for the deoxidation of a shell and is applied to the inside walls of the shell.
13. A process as claimed in claim 1, wherein from 10 to 60 g of deoxidation agent is used per square meter of the inside wall surface of the shell and wherein from 100 to 500 standard liters of gas is used per kilogram of deoxidation agent.
14. A process as claimed in claim 1, wherein the delivery arrangement, during the application of the deoxidation agent, is guided into the hollow space of the shell through the opening of such hollow space.
15. A process as claimed in claim 1, wherein the deoxidation agent is guided through a delivery arrangement located in the area of the end of shell, into the shell and is applied to the inside wall of the shell.
16. A process as claimed in claim 1, wherein the gas is air, nitrogen, CO2, an inert gas or a mixture of at least two such gases.
17. A process as claimed in claim 1, wherein the deoxidation agent is used in dry form as a powder having an average grain size of from 50 to 1000 micrometers or as a granulate having an average grain size of from 0.5 to 4 mm.
18. A process as claimed in claim 1, wherein the pressure container is acted upon with compressed gas so that the pressure therein is from 2 to 20 bars.
19. A process as claimed in claim 1, wherein the deoxidation agent is used for the deoxidation of a shell and is applied to the inside walls of the shell.
20. An apparatus for processing a deoxidation agent according to the process of claim 1, comprising a supply container for the deoxidation agent, a pressure container having an inlet for pressurized gas and an outlet for the gas-deoxidation-agent mixture, and a volumetric or gravi-metric dosing arrangement which is attached to the supply container and which empties into the pressure container, there being valve whereby the outlet of the pressure container is controlled, a conveying line for the apparatus, and a delivery apparatus for the gas-deoxidation-agent mixture on the end of the conveying line.
21. An apparatus as claimed in claim 20, wherein the volumetric dosing arrangement is used as a dosing apparatus.
22. An apparatus as claimed in claim 21, wherein the dosing apparatus is a spiral dosing arrangement.
23. An apparatus as claimed in claim 20, wherein the volumetric dosing apparatus is a spiral dosing arrangement which is used as a dosing apparatus.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CH3571/84 | 1984-07-23 | ||
| CH357184 | 1984-07-23 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1247992A true CA1247992A (en) | 1989-01-03 |
Family
ID=4258862
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000487228A Expired CA1247992A (en) | 1984-07-23 | 1985-07-22 | Process and apparatus for deoxidation of shells for the production of pipes |
Country Status (11)
| Country | Link |
|---|---|
| EP (1) | EP0172366B1 (en) |
| JP (1) | JPH0774468B2 (en) |
| BR (1) | BR8503476A (en) |
| CA (1) | CA1247992A (en) |
| CS (1) | CS540185A2 (en) |
| DD (1) | DD235677A5 (en) |
| DE (1) | DE3562100D1 (en) |
| ES (2) | ES8702808A1 (en) |
| MX (1) | MX167480B (en) |
| PL (1) | PL254623A1 (en) |
| ZA (1) | ZA855468B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1987001058A1 (en) * | 1985-08-16 | 1987-02-26 | Trest "Juzhvodoprovod" | Method for clearing deposits from the inner surface of a pipeline and applying protective coating thereto |
| CH668717A5 (en) * | 1986-07-03 | 1989-01-31 | Lonza Ag | METHOD FOR APPLYING A FLOWABLE SUBSTANCE TO THE INNER SURFACE OF A HOLLOW BODY AND DEVICE FOR CARRYING OUT THE METHOD. |
| CH674164A5 (en) * | 1987-09-29 | 1990-05-15 | Lonza Ag | |
| CN116904999A (en) * | 2023-07-25 | 2023-10-20 | 鞍钢股份有限公司 | Pickling device and pickling method for inner wall of small-aperture pipe fitting |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5258060A (en) * | 1975-11-09 | 1977-05-13 | Kihara Seisakusho | Method of polishing inside ofmetal pipe with small inner diameter |
| JPS5258019A (en) * | 1975-11-09 | 1977-05-13 | Kihara Seisakusho | Method of derusting* cleaning and polishing inner surface of metal tube of small diameter |
| SE8004565L (en) * | 1980-06-19 | 1981-12-20 | Fjaellstroem Bengt | PROCEDURE FOR WASHING OR CLEANING AND RINSE OR DRYING OF RUBBER MATERIALS |
| JPS58211859A (en) * | 1982-06-01 | 1983-12-09 | Atsuji Tekko Kk | Blasting device for internal surface of bent pipe |
| JPS5942273A (en) * | 1982-08-31 | 1984-03-08 | Atsuji Tekko Kk | Grinding and cleaning machine for inside surface of pipe |
| CH655516B (en) * | 1983-08-17 | 1986-04-30 |
-
1985
- 1985-06-28 EP EP85108047A patent/EP0172366B1/en not_active Expired
- 1985-06-28 DE DE8585108047T patent/DE3562100D1/en not_active Expired
- 1985-07-19 JP JP60160030A patent/JPH0774468B2/en not_active Expired - Lifetime
- 1985-07-19 ZA ZA855468A patent/ZA855468B/en unknown
- 1985-07-19 DD DD85278785A patent/DD235677A5/en not_active IP Right Cessation
- 1985-07-19 PL PL25462385A patent/PL254623A1/en unknown
- 1985-07-22 MX MX206068A patent/MX167480B/en unknown
- 1985-07-22 BR BR8503476A patent/BR8503476A/en unknown
- 1985-07-22 ES ES545447A patent/ES8702808A1/en not_active Expired
- 1985-07-22 CS CS855401A patent/CS540185A2/en unknown
- 1985-07-22 CA CA000487228A patent/CA1247992A/en not_active Expired
-
1986
- 1986-02-27 ES ES552462A patent/ES8701854A1/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| ZA855468B (en) | 1986-03-26 |
| EP0172366B1 (en) | 1988-04-06 |
| MX167480B (en) | 1993-03-24 |
| ES545447A0 (en) | 1987-01-01 |
| PL254623A1 (en) | 1986-06-17 |
| EP0172366A1 (en) | 1986-02-26 |
| BR8503476A (en) | 1986-04-15 |
| JPH0774468B2 (en) | 1995-08-09 |
| DE3562100D1 (en) | 1988-05-11 |
| ES8701854A1 (en) | 1986-12-01 |
| DD235677A5 (en) | 1986-05-14 |
| ES552462A0 (en) | 1986-12-01 |
| ES8702808A1 (en) | 1987-01-01 |
| JPS6137987A (en) | 1986-02-22 |
| CS540185A2 (en) | 1991-08-13 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |