JPS594508B2 - How to prevent dripping from the ceiling inside the booth - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for preventing drips from falling from the ceiling inside a booth of an apparatus that continuously chemically treats steel or the like.

The continuous chemical conversion treatment process for steel, etc. generally consists of the steps of "degreasing → water washing → film formation → water washing → drying". It incorporates processes such as washing, surface conditioning, and post-treatment.

The equipment for the chemical conversion treatment generally includes each treatment liquid tank necessary for the valley process, and is installed substantially parallel to the bottom surface of each treatment liquid tank, passing above each treatment liquid tank, and has an inlet and an outlet. It consists of a tunnel-shaped booth, a conveyor extending through the entrance and exit of the booth, and seed power auxiliary equipment. The inside of the booth is comprised of a plurality of processing zones for respectively processing the plurality of steps, a drain zone for the valley processing liquid located between the mutually adjacent processing zones, and a drying zone. Each treatment zone uses either a spray method or an immersion method. When such chemical conversion treatment equipment is operated to continuously process materials such as steel, the booth is filled with water vapor or mist from heating, spraying, etc. in the processing zone where heated processing liquid is used, causing the booth to overflow. Inner "5" Dew condenses on the walls, and the condensation on the ceiling becomes droplets and falls onto the object to be processed.
Droplets falling in each processing zone are not a problem because the object to be processed is covered with the processing liquid, but if drops fall on the object to be processed in each drain zone, the surface of the object to be treated at the droplet area will be covered by the droplets. Subtle chemical changes occur, causing defects in chemical conversion such as the formation of yellow steel and uneven chemical conversion coatings.

Various methods have been used to prevent this droplet from falling.
For example, the ceiling of the booth is sloped so that five drops of condensed water flow down the wall, or a large amount of fresh air is supplied into the booth to discharge water vapor inside the booth.

However, since the former requires a fairly steep slope to the ceiling of the booth, it cannot be installed unless the building is of an appropriate height, and the latter 90% can cause the processed material to dry easily, causing unevenness in the chemical conversion coating. The disadvantage was that a large amount of thermal energy was lost. SUMMARY OF THE INVENTION An object of the present invention is to provide a method for preventing drops from falling from the booth ceiling without inclining the ceiling of the booth or affecting the objects to be processed.

The method for achieving the object of the present invention is to provide a heater directly or in close proximity to the upper ceiling of a drain zone located between mutually adjacent valley treatment zones in the booth, and to adjust the temperature of the lower surface of said ceiling and its surroundings by: This method maintains the temperature above the dew point temperature of the valley processing zone in the booth.

The first embodiment of the present invention will be described with reference to FIG. 1. The chemical conversion treatment apparatus includes treatment liquid tanks 1, 2, and 3 disposed below, and passes above each treatment liquid tank. A tunnel-shaped booth 4 is arranged having an inlet and an outlet substantially parallel to the bottom surface of the
is provided.

In the booth 4, there are three processing zones 1a, 2a, and 3a corresponding to the processing liquid tanks 1, 2, and 3. For example, the processing zones 1a and 3a have a high temperature atmosphere, and the processing zone 2a has a normal temperature atmosphere. . There are drain zones 6a, 6b between adjacent processing zones, and plate heaters 8a, 8.
b is close to the lower surface of the upper ceilings 1a, 7b of the drain zones 6a, 6b, and the planes of the plate heaters are parallel to each other. Plate heaters 8a, 8b are sequentially connected by steam pipes 9a, 9b, 9c,
Plate heaters 8a and 8b are heated by steam so that the temperature is maintained higher than the dew point temperature of processing zones 1a and 3a in the booth, for example, 2° C. or more higher than the ambient temperature thereof. Next, a second embodiment of the present invention will be described with reference to FIG. 2. In place of the plate heaters 8a and 8b of the first embodiment, upper ceilings Ra and rb of drain zones 6a and 6b in the booth 4 are has a double structure and the voids 10a, 10
Ceiling heater with b. 11a, 11b are provided, and the ceiling heaters are connected by steam pipes 9a, 9b, 9c similarly to the plate heater of the first embodiment, and heat the ceiling heaters 11a, 11b with steam to heat the inside of the booth. The temperature is maintained higher than the dew point temperature of the processing zones 1a and 3a, for example, 2° C. or more higher than the ambient temperature thereof.

Plate heater 8a in the above-mentioned first and second embodiments,
8b or the ceiling heaters 11a, 11b may be heated by inducing the heating liquid in the processing liquid tank, or may be heated by inducing other hot water.

When steam is guided from the steam pipe 9a to the plate heater 8a or the ceiling heater 11a, the lower surface of the plate heater 8a or the ceiling heater 11a is heated, and the plate heater 8
The area around a and the lower surface of the ceiling close to the plate heater or the lower surface of the ceiling heater 11a and its surroundings are maintained at a temperature higher than the dew point temperature of the atmosphere in the rebooth, which is a high temperature atmosphere, and no dew condensation occurs. Plate heater 8a or ceiling heater 11
The steam guided to a is introduced to the next plate heater 8b or the next ceiling heater 11b through the next steam pipe 9b, and is discharged from the steam pipe 9c. As described above, by carrying out the present invention, dew condensation does not form on the upper ceiling surface of the drain zone located between the mutually adjacent processing zones in the booth.
9, chemical formation defects such as occurrence of yellow rust and unevenness of chemical conversion coating are eliminated.

[Brief explanation of drawings]

1 and 2 are diagrammatic side sectional explanatory views of first and second embodiments of the present invention. 1, 2, 3... Processing liquid tank, 1a, 2a, 3a.
...Processing zone, 4...Booth, 5...
...Conveyor, 6a, 6b...Drain zone, Ra, rb...Upper ceiling, 8a, 8b...
...Plate heater, 9a, 9b, 9c...
...Steam pipe, 10a, 10b...Gap, 1
1a, 11b...Ceiling heater.

Claims (1)

[Claims] 1. In an apparatus having a plurality of processing zones for continuous chemical conversion treatment of steel, etc., directly or adjacent to the upper ceiling of the drain zone located between the mutually adjacent processing zones in the booth of the apparatus. Install a heater,
A method for preventing drops from falling from a ceiling inside a booth, characterized by making the ceiling higher than the dew point temperature inside the booth.