JPS5827985A - Controlling method for dip coating type phosphating - Google Patents

Abstract

PURPOSE:To perform efficient control by providing plural hoppers in the bottom part of a treating tank, connecting the hoppers to the suction side of a pump, connecting the discharge side to a means for separating and removing sludge and a system for returning sludge removing liquid to the treating tank, and changing over the connection of the hoppers and the pump during the treatment. CONSTITUTION:For examples, 4 hoppers 3-6 are provided in the bottom parts of a dip coating type treating tank 1, and the hoppers are connected to the suction side of a pump 13 via pipes 7-11 with valves and a conduit 12. The discharge side of the pump 13 is connected via a conduit 14 to a concentrating tank 15, and further to a filter 17 and a conduit 18 for returning the filtrate to the tank 1. First, only the hopper 2 is communicated with the pump 13, and part of the sludge and treated liquid in the hopper 2 are discharged to the tank 15. Upon lapse of a prescribed time, the communication between the hopper 2 and the pump 13 is interrupted and the hopper 3 is communicated with the pump 13. The sludge is discharged sequentially from the hoppers 4, 5, 6. After the treated liquid in the tank 15 is removed of sludge 19 with the filter 17, the liquid is returned through the conduit 18 into the tank 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for managing immersion phosphate treatment, and more specifically, a method for managing sludge generated and accumulated in a treatment tank.
This invention relates to an efficient and economically advantageous method for evacuation.

In the immersion type phosphate treatment, sludge is generated and accumulated in the tank in which the material to be treated is chemically treated, but when the concentration in the tank reaches a predetermined value or higher, the sludge may adhere to the material to be treated. Since this makes it impossible to carry out a satisfactory chemical conversion treatment, an operation for removing the sludge in equal portions is usually carried out in parallel with the chemical conversion treatment. To do this, a part of the treated liquid in the tank containing sludge can be continuously taken out of the tank and the sludge can be separated and removed using a means such as a filtration device, but the sludge is in the form of fine particles. Because it's hard to resist,
There is a problem in that a large load is placed on the tlf means and a large-sized device is required. In order to improve this point, a treated flower 1 having a popper at the bottom as used in the present invention is used, and the generated sludge is allowed to settle in the hopper, and the sludge is raised together with the treatment liquid from the hopper. It is carried out to continuously take out the water from the tank at a certain rate. However, according to the Kagaru treatment sanitation management method, a large amount of treatment liquid is simultaneously discharged to the outside of the tank in order to take it out of the tank without leaving any sludge that settles in the potspar.
Large-sized auxiliary equipment is required for sludge separation and removal. In addition, since the treatment liquid during chemical conversion treatment is generally heated to a predetermined temperature, taking a large amount of treated i& out of the tank as described above will lead to heat dissipation, which will require reheating, resulting in thermal damage. It is also uneconomical.

The present invention solves the problems of the prior art described in item 1 and provides a management method that can efficiently separate and remove sludge in a treatment tank using miniaturized auxiliary equipment and reduce thermal loss of the treatment liquid. do.

That is, the gist of the present invention is to use a submerged treatment tank having a plurality of hoppers at the bottom, each hopper being connected to the suction side of one pump, and the discharge side thereof being connected to a sludge separation and removal means and then to a sludge removal treatment liquid. The sludge in each hopper is discharged from each hopper to the outside of the tank by connecting it to the system for returning it to the treatment tank described in 1 above, and switching the connection between the hopper and the pump at predetermined intervals during the immersion process. The management method for immersion phosphate treatment is based on

Next, the present invention will be specifically described with reference to the accompanying drawings. 1
1 is a submerged treatment tank, and a plurality of hoppers (5 in the illustrated case) 2 to 6 are provided at the bottom of the tank. The number of hoppers may be selected as appropriate depending on the various conditions of the immersion treatment. For example, in a treatment tank with a capacity of 110 that processes 7,000 automobile bodies per month, five hoppers with a capacity of 5 doors may be provided. is suitable. Each hopper 2-6 is provided with valved pipes 7-11, which are connected by a main pipe 12 to a pump 13 on its suction side. The other end of the main pipe 14 provided on the discharge side of the pump 13 is connected to a storage tank 15 for a sludge-containing treatment liquid.
The liquid side (connected to the treatment tank 1 by means of the J-special pipe 18,
The dregs side is connected to a dehydrated cake receiving tank 19.

In the apparatus having the above configuration, the method of the present invention includes:
First, only the hopper 2 is communicated with the pump 13, and the sludge in the hopper is discharged into the tank 15 together with a portion of the processing liquid. After performing this operation for a predetermined time, hopper 2
The communication between the hopper 3 and the pump 13 is cut off, and then the communication between the hopper 3 and the pump 13 is established, and the sludge in the hopper 3 is discharged in the same manner as in 1.
The sludge in the hopper is sequentially discharged in the same manner.

-4- As mentioned above, the time required to connect each hopper 2 to 6 with the pump 13 and discharge the sludge from each hopper to the outside of the tank is calculated based on the treatment tank capacity and the area to be treated per unit time. , hopper capacity, number of hoppers, pump capacity, etc. may be selected as appropriate depending on various requirements.
(processing at a rate of 7,000 units/month in the treatment tank of A),
In order to maintain the sludge concentration in the treatment tank at 1.15 PPm, one
001! When a pump 13 with a capacity of /min is connected,
Drainage of the liquid was started 3 hours after the start of the chemical conversion treatment, and the sludge concentration in the discharged treatment liquid at a predetermined time from that time changed on average for each hopper as shown in the left column (5) of the table below. Furthermore, when the hindlimb operation is stopped for 3 hours after draining for a predetermined period of time, and then the operation is restarted, the sludge concentration in "1" changes as shown in 4hη on the right side of the table below.

As is clear from the second result, the sludge concentration in the drained liquid immediately after the start of draining reaches 70,000 to 1,100,000 pp, which is about 600 times the concentration in the tank. However,
The sludge concentration drops rapidly during about 60 to 180 seconds after the start of draining, and reaches a steady state after about 3 minutes, being only about twice the concentration in the tank (1151'Pm). Therefore, in this example, it is appropriate that the sludge discharge operation time from each popper be within about several minutes AI.

By sequentially discharging the sludge in the hopper from each hopper in this way, the treatment liquid containing high concentration of sludge can be discharged to the outside of the tank, and at the same time, the sludge concentration in the treatment tank can be maintained at a predetermined value. . Therefore, since the sludge content of the discharged liquid is high, the subsequent sludge separation and removal operation can be carried out efficiently, and the slurry concentration work using the tank 15 that is conventionally employed is not necessarily necessary, and the slurry can be directly transferred to the offshore filter 17. A sludge-containing treatment liquid may be introduced, the ρ liquid may be returned to the treatment tank 1 via a conduit 18, and the sludge may be discharged into a receiving tank 19. In addition, since the amount of sludge-containing discharged liquid is small, the capacity of the r-filter 17 can be reduced.

Also, since the sludge-containing treatment liquid is discharged from the hoppers in sequence for each hopper, the discharge operation can also be carried out with a single pump with a small capacity. As described above, the present invention is highly advantageous in reducing the size of incidental equipment for discharging sludge from a treatment tank and separating and removing it.
Since the amount of processing liquid taken out of the tank is small, thermal loss due to the processing liquid is naturally reduced.

Furthermore, as is clear from the table, even if the operation is stopped for a certain period of time after the sludge-containing treatment liquid has been discharged to the outside of the tank for a predetermined period of time, and then the operation is started, The sludge concentration can be maintained at a predetermined value (115 ppm) by 1) simply discharging the high-concentration sludge-containing treatment liquid to the outside of the tank in the same manner as in one discharge operation; Intermittent discharge operation is even more advantageous in the present invention. Note that the discharging operation interruption time at this time may be appropriately selected according to various requirements, as in the case of the series of explanations regarding the discharging operation time from the hopper, and generally one hour to several days is appropriate. .

To describe this intermittent discharge operation in more detail based on a criminal case, the discharge operation is started 3 hours after the start of chemical conversion treatment, and is carried out sequentially for each hopper with a discharge time of 30 seconds.This is called one cycle. - If the operation is carried out by interrupting the discharge operation for 3 hours after the cycle and carrying out the next cycle, the sludge concentration in the drained liquid per cycle will be as follows per cycle (i.e. 150 seconds): A small amount of treatment liquid containing high concentration sludge (i.e. 250J)
By simply discharging the sludge, the concentration of sludge in the treatment tank can be reduced to a predetermined value (11
5 ppm), and the operation can be interrupted for 3 hours between cycles, making it possible to carry out very advantageous chemical conversion treatment management in terms of incidental equipment.

[Brief explanation of the drawing]

FIG. 1 shows an outline of a chemical conversion treatment apparatus for carrying out the method of the present invention, in which symbol (2) is a treatment tank, 2 to 6 are hoppers, 13 is a pump, 15 is a concentration tank, and 17 is an evaporator. Patent applicant Nippon Paint Co., Ltd.

Claims (1)

[Claims] 1. A submerged treatment tank having a plurality of hoppers at the bottom is used, each hopper is connected to the suction side of one pump, and the discharge side is connected to the sludge separation and removal means and then to the sludge removal treatment liquid. is connected to the system that returns it to the above treatment tank, and during the immersion process,
Switch the connection between the hopper and the pump at predetermined intervals,
A method for managing immersion phosphate treatment characterized by sequentially discharging sludge from each hopper to the outside of the tank. 2. The method according to item 1 above, in which sludge is discharged from the hoppers in an intermittent manner, in which the discharge operation is interrupted for a predetermined period of time after one round of sludge discharge from each hopper, and then the discharge operation is restarted. .