US3473962A

US3473962A - Process and apparatus for treating a strip material with liquid

Info

Publication number: US3473962A
Application number: US637199A
Authority: US
Inventors: Josef Hampel
Original assignee: Ruthner Industrieplannungs AG
Current assignee: Ruthner Industrieplannungs AG
Priority date: 1967-05-09
Filing date: 1967-05-09
Publication date: 1969-10-21
Anticipated expiration: 1986-10-21

Description

Get. 21, 1969 J HAMPEL 3,473,962

PROCESS AND APPAR ATUS FOR TREATING A STRIP MATERIAL WITH LIQUID Filed May 9, 1967 INVENTOR J'OSEF HAMPEL BY X 16% ATTORNEYS United States Patent 3 473,962 PROCESS AND APPARATUS FOR TREATING A STRIP MATERIAL WITH LIQUID Josef Hampel, Vienna, Austria, assignor to Ruthner Industrieplanungs-Aktiengesellschaft, Vienna, Austria Filed May 9, 1967, Ser. No. 637,199 Int. Cl. B081) 3/08, 1/02 U.S. (Cl. 134-15 6 Claims ABSTRACT OF THE DISCLOSURE The invention relates to a process and apparatus for treating a material with liquid during a continuous movement of the material through a treating plant. The material being treated may consist of strip, sheets, sections or wire of any kind. The material may be moved through the plant by being pulled and/0r pushed.

The treatment may be effected with one or more liquids.

In the production of semi-manufactured metallic products, the surfacefinishing and treatment of strip, sheets, sections and wire by a treatment of such material with various liquids is of considerable significance. Continuous processes in which the material is pulled and/ or pushed through the liquid are carried out at a very high rate.

It has been found that many of these processes, which chemical or physical changes of the liquid are effected in the boundary layer, e.g., as a result of chemical reactions taking place at the surface of the metal, can be much accelerated if an intense movement relative to the surface of the material being treated is imparted to the liquid. The resulting agitation reduces the thickness of the immovable boundary layer so that for given coeflicients of diliusion and/or thermal conductivity etc. the rate of the change of the nature of the liquid at the surface of the material is highly reduced. In a given plant, the treating time can thus be reduced and the rate of material flow can be much increased.

A first step in this direction was to provide various devices in which the liquid was agitated in the trough through which the material being treated was moved. This agitation was effected by stirring, circulation, forcing the liquid through nozzles directed toward the material being treated, etc.

It is also known merely to spray the liquid onto the material being treated, which in this case is not immersed into a still liquid, but is only flown over by the sprayed liquid, which subsequently drains from the material being treated. Such nozzles require large pressures and the pumps being used may have to meet high requirements, e.g., if aggressive liquids are employed. An intense relative movement is obtained only at those points of the material being treated where the jet from the nozzles directly impinges.

An essential feature of the invention resides in the treating steps comprise passing the stock through at least one trough, which is at an angle to the vertical, supplying said liquid at a predetermined point of the trough, moving the liquid along said trough in contact with the stock to be treated, intensifying the relative movement between the liquid and the stock by retaining the liquid at successive points, which are spaced apart in the direction of flow of the liquid through the trough, and discharging the liquid from the trough at a point which is spaced from the point of supply and at which substantially the entire liquid flows from the trough when the supply of liquid is interrupted.

Another feature of the invention resides in an apparatus for carrying out the process, comprising at least one trough, which is at an angle to the vertical and serves for receiving and guiding the treating liquid and the material to be contacted by it, a plurality of rollers for supporting and moving the material to be treated, at least one of said rollers being driven, means for supplying and discharging the treating liquid at two spaced apart points, and retaining members which dip from above into the liquid at points which are spaced apart in the direction of flow, said retaining members extending almost to the top of the material being treated.

It is also a feature of the invention to provide a plurality of troughs which are disposed one over the other and through which the material is moved along a zigzag path and around deflecting rollers, successive ones of said troughs being inclined in mutually opposite directions, and means being provided for discharging liquid from the lowermost point of the lowermost trough and means for transferring liquid from the lowermost point of one trough to the uppermost point of the next lower trough.

The drawing is a longitudinal sectional view showing by way of example a plant according to the invention. Preceding and succeeding equipment, such as coilers and uncoilers, shears, joining devices and the like are without significance for the invention and have been omitted.

The stock to be treated may consist of metal strip 1 which is joined to be endless and enters the entirely enclosed plant 2 through the inlet slot 3. The stock is moved by means of supporting rollers 4, deflecting rollers 5, auxiliary rollers 6 and presser rollers 7 through two treating troughs 8, which lie one over the other. The stock leaves the plant through an outlet slot.

In the embodiment shown by way of example, a single treating liquid is used, which is charged e.g., by a pump, not shown, and the supply pipe 9 under no pressure to the upper end of the uppermost of the three inclined treating troughs 8. The liquid flows through the troughs in succession in the direction of movement of the strip. This direction is reversed between successive troughs. At three overflows 10, the liquid is transferred to a lower trough or from the plant into a reservoir on a lower level or the sewer. A plurality of retaining members 11 are disposed over each trough and consist of vertical rectangular flaps, which are hinged at their top on horizontal axes 12 extending transversely to the direction of flow. Each of these flaps retains the flowing liquid to some extent and forces it to flow under the flap at a high velocity in a thin layer over the material being treated. In this way the effect according to the invention is obtained, which resides in a highly intense agitation to reduce the thickness of the boundary layer and treating time. In the present example, the flaps tend to assume a vertical position by gravity and any deflections from said position are controlled by gravity. Alternatively, the deflection may be controlled by additional Weights, springs or the like, or by subjecting the lower edge of the flaps to a certain deflecting force. In this way the flaps may be used for an adjustable control of the level to which the liquid is retained in front of them.

By the provision of a plant which is fully enclosed, the disadvantages are avoided which are inherent in the evaporation of volatile liquids or in the action of aggressive liquids or the smell of liquids having an unpleasant odor. With various means, the openings or slots through which the material being treated continuously enters and leaves the apparatus can be designed to prevent any substantial escape of gases from the apparatus to the outside at these points. A simple expedient is the use of a small blower, which sucks a small amount of gas from the interior of the apparatus and delivers said gas into the outside so that the resulting slight vacuum reliably prevents an escape of gas at another point.

It will be understood that the invention is not restricted to the embodiment which has been described by way of example. If the length of the plant is not restricted, the plurality of troughs which have been proposed may be replaced by a single trough.

The form of the troughs is suitably rectangular and fiat. It is important that the treating liquid or liquids should be supplied to and discharged from the trough or troughs at points which are spaced apart in the longitudinal direction so that the liquid moves in a co-current or counter-current flow to the flooded material. The liquid is or the liquids are drained at least from a major part of the length of the trough or troughs when the supply of liquid is interrupted. The cross-section of flows is restricted in the vertical dimension at a plurality of points of the trough or troughs by walls, flaps, displacing members or the like so that the liquid is retained in front of such points and an intense relative movement between the liquid and the material being treated is obtained at such points.

In the drawing, the troughs are slightly inclined; they may also be horizontal. The movement of the material being treated may be effected in that individual ones of the rollers shown are driven or by additional driven rollers, which may be disposed inside or outside the plant.

Whereas supply containers and pumps are required for the operation of the plant, they do not belong to the invention proper and have been omitted for the sake of simplicity.

The retaining members which dip from above into the liquid or liquids flowing through the troughs normally do not contact the material being treated or only slightly contact it and may have forms other than that described.

The retaining members may be displacement bodies, such as tubular members, which are horizontally disposed and transversely to the direction of flow, or partitions having lower edges which terminate above the material being treated, or, in a preferred embodiment, flaps which occupy a major part of the cross-section of the trough or troughs above the material being treated and in most cases are rectangular in adaptation to the cross-section of the trough. The flaps are preferably suspended at their top from a horizontal axis of rotation, which is transverse to the direction of flow, so that the flaps can yield to the joints between succeeding strips or the like. In a particularly preferred embodiment, the distance between the material being treated and the lower edge of the flaps is variable by means which enable a vertical adjustment of each flap relative to its axis of rotation or of the axis of rotation relative to the trough. Such means are known per se in mechanical engineering.

What is claimed is:

1. A process of treating strip metal stock with liquid during a continuous movement of the stock through a treating plant, which process comprises the treating steps of passing the stock through at least one trough, which is at an angle to the vertical, supplying said liquid at a predetermined point of the trough, moving the liquid along said trough in contact with the stock to be treated, intensifying the relative movement between the liquid and the stock by retaining the liquid at successive points in the trough, which are spaced apart in the direction or flow of the liquid through the trough, and discharging the liquid from the trough at a point which is spaced from the point of supply and at which substantially the entire liquid flows from the trough when the supply of liquid is interrupted.

2. Apparatus for treating a strip material with liquid during the continuous movement of the material through a treating plant, which apparatus comprises at least one trough, which is at an angle to the vertical and serves for receiving and guiding the treating liquid and the material to be contacted by it, a plurality of rollers for supporting and moving the material to be treated, at least one of said rollers being driven, means for supplying and discharging the treating liquid at two spaced apart points, and retaining members which dip from above into the liquid at points which are spaced apart in the direction of flow, said retaining members extending almost to the top of the material being treated.

3. Apparatus as set forth in claim 2, in which the troughs have a rectangular cross-section.

4. Apparatus according to claim 2, in which said retaining members consist of flaps, said flaps being hinged on a horizontal axis which extends transversely to the direction of flow, and said flaps filling a major part of the cross-section of the trough above the material being treated.

5. Apparatus as set forth in claim 2, in which a plurality of troughs are present and are disposed one over the other and through which the material is moved along a zigzag path and around deflecting rollers, successive ones of said troughs being inclined in mutually op posite directions, and means being provided for discharging liquid from the lowermost point of the lowermost trough and means for transferring liquid from the lowermost point of one trough to the uppermost point of the next lower trough.

6. Apparatus as set forth in claim 2, further comprising a housing which tightly surrounds the treating space and has narrow slots for receiving and discharging the treating liquid and the material being treated.

References Cited UNITED STATES PATENTS 1,544,506 6/1925 Tytus 134-15 2,141,382 12/1938 Ferm 134-64 XR 2,234,593 3/1941 Ferm et al. 134-15 XR 2,359,095 9/1944 Elder et al. 134l5 XR MORRIS O. WOLK, Primary Examiner BARRY S. RICHMAN, Assistant Examiner US. Cl. X.R. 134-32, 34, 64