JPH0639960U - Pretreatment device - Google Patents

Abstract

(57) [Summary] [Purpose] The heat exchange efficiency of the heat exchanger that heats the treatment liquid in the pretreatment tank to a predetermined control temperature is improved, and the heat is circulated and supplied from the pretreatment tank to the inside of the heat exchanger. It prevents the sludge contained in the treatment liquid from adhering to lower the heat transmission efficiency. [Structure] A sludge discharge pipe 6 for sucking and discharging sludge settled on a V-shaped bottom 4 of a pretreatment tank 1 together with a treatment liquid, and a treatment liquid circulation pipe for supplying the treatment liquid in the pretreatment tank 1 to a heat exchanger 8 in a circulating manner. 7 is a forward pipe 9 and a centrifugal separator 11 for removing sludge in the treatment liquid discharged from the sludge discharge pipe 6 is interposed in the forward pipe 9 and the sludge is removed by the centrifugal separator 11. The clean processing liquid thus prepared is sent to the heat exchanger 8.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a pretreatment device for performing a pretreatment for painting or plating.

[0002]

[Prior art]

 The pre-treatment device for pre-treatment of automobile coating is the treatment of degreasing liquid and film forming liquid etc. stored in the main tank of the pre-treatment tank for large objects such as automobile bodies transferred on the hanger of the conveyor. It is designed to be immersed in liquid. A plurality of V-shaped bottoms for accumulating sludge that settles on the tank bottom are formed on the bottom of the main tank, and the sludge accumulated on the bottom is sucked out of the tank together with the treatment liquid at each V-shaped bottom. The sludge discharge pipe is connected (Actual Publication No. Sho 63-761). The treated liquid discharged from the sludge discharge pipe is passed through a filter such as a settling tank to remove sludge and then returned to the main tank again.

Further, in the pretreatment tank, in order to maintain the treatment liquid in the main tank in which the object to be treated is immersed at a predetermined control temperature, the treatment liquid overflowed from the main tank into the sub tank is sent to a heat exchanger. A processing solution circulation pipe is provided for heating and returning the heated processing solution into the main tank (Japanese Utility Model Publication No. 60-31083).

[0004]

[Problems to be solved by the device]

 In the conventional pretreatment device configured as described above, for example, since the chemical conversion sludge adheres to the inside of the heat exchanger that heats the film forming liquid, which is the processing liquid, and the heat transmission coefficient decreases, the inside of the device is regularly However, if the cleaning frequency is low, it will be extremely difficult to completely remove the deposited chemical sludge as a stone. In addition, in order to keep the treatment liquid stored in the main tank of the pretreatment tank at a predetermined control temperature, the treatment liquid overflowing from the main tank into the sub tank is sent to a heat exchanger, where hot water heated by steam is used. Although it is heated by heat exchange with the sub-tank, the treatment liquid overflowing into the sub-tank is a comparatively high-temperature treatment liquid existing on the liquid surface of the main tank, and the temperature of the treatment liquid sent from the sub-tank to the heat exchanger is The heat exchange efficiency of the heat exchanger is never good because there is no big difference with the temperature of the treatment liquid in the main tank heated by the heat exchanger.

In view of this, the present invention improves the heat exchange efficiency of a heat exchanger that heats the treatment liquid in the pretreatment tank to a predetermined management temperature, and reduces the heat transmission coefficient inside the heat exchanger. It is a technical issue to prevent them from adhering.

[0006]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention provides a forward pipe for sending a treatment liquid in a pretreatment tank to a heat exchanger, and a return pipe for returning the treatment liquid heated by the heat exchanger to the pretreatment tank again. In the pretreatment equipment equipped with a treatment liquid circulation pipe consisting of and a sludge discharge pipe for sucking and discharging the sludge settled from the V-shaped bottom forming the bottom of the pretreatment tank to the bottom together with the treatment liquid, The pipe serves as a forward pipe of the treatment liquid circulation pipe, and a centrifugal separator for removing sludge contained in the treatment liquid discharged from the sludge discharge pipe is provided in the forward pipe, and the centrifugal separator concerned It is characterized in that a clean treatment liquid from which sludge has been removed by is sent to the heat exchanger.

[0007]

[Action]

 According to the present invention, the treatment liquid sucked and discharged from the V-shaped bottom of the pretreatment tank through the sludge discharge pipe is sent to the heat exchanger for heating, so that the heat exchange efficiency of the heat exchanger is extremely high. Good for That is, the temperature of the treatment liquid stored in the pretreatment tank becomes lower as it gets closer to the bottom of the tank, especially at the V-shaped bottom where the treatment liquid tends to stagnant, so that the treatment liquid discharged from the V-shaped bottom is removed. The heat exchange efficiency of the heat exchanger for heating is significantly increased.

Further, the forward pipe of the treatment liquid circulation pipe for feeding the treatment liquid in the pretreatment tank to the heat exchanger is formed by a sludge discharge pipe for discharging the treatment liquid containing a large amount of sludge as compared with the conventional case. However, since the sludge discharge pipe is equipped with a centrifugal separator that removes sludge from the treatment liquid, a clean treatment liquid with a smaller sludge content than before is sent to the heat exchanger. . Therefore, it is possible to reliably prevent the sludge from adhering to the inside of the heat exchanger, and to significantly reduce the frequency of cleaning the heat exchanger.

[0009]

【Example】

 Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a flow sheet diagram showing an example of a pretreatment apparatus according to the present invention.

In the figure, reference numeral 1 denotes a pretreatment tank comprising a main tank 2 for immersing an object to be treated in a treatment liquid, and a sub-tank 3 for storing the treatment liquid overflowing from the main tank 2. A plurality of V-shaped bottoms 4 for accumulating sludge that settles on the tank bottom are formed on the bottom of No. 2, and a sludge discharge pipe for sucking and discharging the sludge settled and accumulated on each V-shaped bottom 4 with a pump 5. 6 is connected.

Reference numeral 7 denotes a forward pipe 9 that sends the treatment liquid in the pretreatment tank 1 to the heat exchanger 8, and a return pipe 10 that returns the treatment liquid heated in the heat exchanger 8 to the pretreatment tank 1 again. The forward pipe 9 is formed by the sludge discharge pipe 6, and the forward pipe 9 is a centrifugal device for removing sludge contained in the process liquid discharged from the sludge discharge pipe 6. A separator 11 is interposed so that the clean treatment liquid from which sludge has been removed by the centrifuge 11 is sent to the heat exchanger 8. The sludge separated from the treatment liquid by the centrifuge 11 is discharged out of the system through the drain pipe 12 provided in the centrifuge 11.

Further, the return pipe 10 for returning the treatment liquid heated through the heat exchanger 8 to the pretreatment tank 1 blows a jet of the treatment liquid onto the sludge settling on the outlet side slope of the main tank 2. The spray riser pipe 14 that is connected to the spray riser pipe 13 that drops into the V-shaped bottom 4 and that drops the sludge that has settled on the inlet side slope of the main tank 2 into the V-shaped bottom 4 overflows from the main tank 2 into the sub-tank 3. A circulation pipe 16 for returning the treatment liquid to the main tank 2 with a pump 15 is connected. Reference numeral 17 denotes a hot water circulation pipe for sending hot water in the hot water tank 19 heated by the steam injected from the steam pipe 18 into the heat exchanger 8 by the pump 20.

Therefore, the treatment liquid sent from the inside of the main tank 2 to the heat exchanger 8 through the sludge discharge pipe 6 is the lowest temperature treatment liquid discharged from the V-shaped bottom 4 formed at the bottom of the main tank 2. Therefore, the heat exchange efficiency with the hot water sent from the hot water tank 19 to the heat exchanger 8 through the hot water circulation pipe 17 becomes extremely good. Further, since the sludge is effectively removed by the centrifuge 11 in the process liquid sent to the heat exchanger 8 through the sludge discharge pipe 6, the amount of sludge adhering to the inside of the heat exchanger 8 is greatly increased. Decrease to.

According to the experiment, when the treatment liquid having a sludge content of 450 P.PM discharged from the V-shaped bottom 4 is passed through a filter such as a settling tank which has been conventionally used, the sludge content is about When it passed through the centrifuge 11, it decreased to about 100 P.PM while it decreased to only 250 P.PM. When the treatment liquid from which sludge was removed by the centrifuge 11 was passed through the heat exchanger 8, the amount of sludge adhering to the inside of the heat exchanger 8 was reduced to about one-third that of the conventional method. The cleaning frequency of the heat exchanger 8 was also greatly reduced.

[0015]

[Effect of device]

 According to the present invention, the heat exchange efficiency of the heat exchanger for heating the treatment liquid in the pretreatment tank to a predetermined control temperature is improved, and at the same time, the amount of sludge adhering to the inside of the heat exchanger is significantly reduced. This has the excellent effect of significantly reducing the frequency of cleaning the heat exchanger.

[Brief description of drawings]

FIG. 1 is a flow chart showing an example of a pretreatment device according to the present invention.

[Explanation of symbols]

 1 ... Pretreatment tank 4 ... V-shaped bottom 6 ... Sludge discharge pipe 7 ... Treatment liquid circulation pipe 8 ... Heat exchanger 9 ... Forward pipe 10 ... Return pipe 11 ... ··centrifuge

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tetsuo Meikaka 1-9 Kakimoto-cho, Toyota City, Aichi Prefecture Trinity Industry Co., Ltd. (72) Sadaharu Nagai, 1 Toyota-cho, Toyota City, Aichi Prefecture Toyota Automobile Co., Ltd.

Claims (1)

[Scope of utility model registration request] 1. A forward pipe (9) for sending the treatment liquid in the pretreatment tank (1) to a heat exchanger (8), and the treatment liquid heated by the heat exchanger (8) is again treated as a pretreatment tank. The treatment liquid circulation pipe (7) consisting of the return pipe (10) returning to (1) and the sludge settled from the V-shaped bottom (4) forming the bottom of the pretreatment tank (1) to the bottom together with the treatment liquid. In the pretreatment device provided with a sludge discharge pipe (6) for sucking and discharging, the sludge discharge pipe (6) is a forward pipe (9) of the treatment liquid circulation pipe (7).
And a centrifugal separator (11) for removing sludge contained in the treatment liquid discharged from the sludge discharge pipe (6) is interposed in the forward pipe (9), and the centrifugal separator (11) ), A clean treatment liquid from which sludge has been removed is sent to the heat exchanger (8).