JPH0230445Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a metal surface treatment apparatus, particularly an immersion closed type surface treatment apparatus.

[Conventional technology]

When forming a film such as painting on a metal product, the base surface is chemically degreased, chemically converted, or treated with chromic acid, phosphoric acid, or the like. One of the metal surface treatment methods is to arrange multiple immersion tanks, immerse the object to be treated in the chemical baths, and then sequentially transfer it to the next washing tank and repeat the immersion, and wash off the chemical solution with washing water. The means are widely used. This immersion method has the advantage of being able to spread the chemical solution and washing water to every corner of the workpiece, even if the shape or structure of the workpiece is complex, so it is used as a backside treatment method for workpieces that cannot be treated adequately with the spray method. ing.

[Problems that this invention attempts to solve]

However, in conventional immersion type metal surface treatment equipment, in order to prevent the cleaning effect from decreasing due to an increase in the amount of chemicals brought into each washing tank, fresh water is simply supplied to the final tank of each washing tank. Since the process was only carried out sequentially, a large amount of harmful wastewater containing chemical components was generated, which required a great deal of effort to dispose of, resulting in high equipment costs and running costs.

As a countermeasure, fresh water is supplied to the final stage of the flushing zone, the resulting surplus water is sent one after another to the preceding flushing zone, and the surplus water from the first stage flushing zone is transferred to the chemical tank at the preceding stage. A known method is to evaporate a chemical solution or washing water in a washing zone or a washing zone near the washing zone, and exhaust the liquid with a fan.

Although this method can reduce wastewater compared to the simple fresh water advance method described above, the latent heat required to evaporate the water is mainly used as fuel (for example, butane gas) to heat the chemical tank. The problem was that fuel costs were extremely high and running costs were high.

In addition, in the chromate treatment of aluminum products, large amounts of harmful substances are contained in the chemical solution, but the methods described above are ineffective in treating these harmful substances, and in some regions, wastewater is regulated due to the risk of pollution. In some cases, the surface treatment itself could not be carried out because of this.

[Means for solving problems]

The present invention is an attempt to solve the problems of the conventional immersion type surface treatment equipment as mentioned above. It can be heated, and at the same time, it can efficiently recover chemical solutions containing harmful substances without adversely affecting the chemical processing process.
Another object of the present invention is to provide a closed type immersion type surface treatment device that can accurately prevent the generation of surplus water due to the cleaning water forwarding method and can significantly reduce the amount of fresh water used for cleaning.

In order to achieve the above object, the present invention provides a tunnel-shaped booth with a chemical liquid zone and a multi-stage water washing zone following the chemical liquid zone, the chemical liquid zone is equipped with a chemical liquid tank for immersion containing an aqueous solution containing a chemical agent, and the water washing zone is equipped with a chemical liquid tank for immersion containing an aqueous solution containing a chemical agent. The booth is equipped with a conveyor that suspends the workpiece and sequentially immerses, pulls up, and transfers the workpiece into the immersion chemical tank and the immersion tank. An immersion method is provided in which means is provided to sequentially advance the washing water from the immersion tank until it reaches the chemical solution zone, and spray water washes the workpieces pulled up from the tank, and the final washing zone is provided with a means to perform adhesion replacement with fresh water. In the type surface treatment equipment, the chemical liquid tank for immersion is connected by a circulation system having a heat pump, and the upper side near the chemical liquid zone is divided by a booth and a partition wall, and the upper part is connected to the refrigerant evaporator side of the heat pump via an exhaust duct. An evaporation chamber is provided separately, a spray mechanism connected to the immersion chemical tank via a pump is provided in the evaporation chamber, and a hot air introduction section from the outside is provided.

[Effect]

With the above configuration, the object to be treated is immersed in a chemical tank for immersion in the chemical zone, and then the adhering liquid that has been immersed in the immersion tanks in several stages of washing zones is washed off. In a dedicated evaporation chamber near and divided into
While the chemical solution from the immersion chemical tank is sprayed by the spray nozzle mechanism, hot air is blown from the hot air introduction section. The evaporation chamber is isolated from the chemical processing space and the material transfer space, so it does not have a negative impact on the chemical processing process, and the amount of hot air introduced, temperature, and chemical spray amount is highly flexible, allowing the chemical to evaporate efficiently. be able to.

The evaporated water is then sent from the evaporation chamber to the heat pump's refrigerant evaporator, where it is cooled and exhausted into the atmosphere, and the condensed water is sent as washing water to the final stage washing zone for reuse. be done.

On the other hand, the refrigerant in the heat pump enters the condenser after exchanging heat with steam as described above, but since the chemical liquid is fed here from the chemical zone through circulation piping, the latent heat generated by condensing water The chemical solution is heated, providing all or part of the heat equivalent to the heat of vaporization of water. This allows evaporation to continue effectively without fuel.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an outline of the immersion type closed type surface treatment apparatus according to the present invention, and FIG. 2 shows the main parts of the apparatus according to the present invention. FIG. 3 is a system diagram of the present invention, and for convenience of explanation, the evaporation chamber of FIG. 2 is shown in an expanded state, that is, on the same plane as the booth of the chemical liquid zone.

Similar to known devices of this type, the device of the present invention has the following features:
The tunnel-shaped booth has a chemical solution zone 1 and a plurality of water washing zones 2A to 2F following this. 3 is a pre-treatment drying furnace, 4 is a painting section, and 5 is a paint baking furnace. A conveyor H is installed from the chemical zone 1 to the paint baking furnace 5, and the objects I to be treated such as metal products are transported by this conveyor H. and chemical zone 1
From there, it stops sequentially in washing zones 2A to 2F,
By being raised and lowered, it is immersed in chemical solutions and washing water.

The chemical solution zone 1 has a tunnel-like booth (second
(the upper part is omitted in the figure) 26 and a lower chemical liquid tank 6 for immersion.
is housed therein, and the workpiece I transferred by the conveyor H is immersed therein, and then pulled up. On the other hand, the first washing zone 2A to the sixth washing zone
The washing zone 2F also has immersion tanks 8a to 8f, each containing washing water, as shown in Fig. 3, into which the workpieces I transferred by the conveyor H are sequentially immersed and then pulled up. .
In the illustrated example, an immersion tank 8a in the first washing zone 2A and an immersion tank 8f in the sixth washing zone 2F.
A heating means 7 is provided for washing with hot water.

Each of the immersion tanks 8a to 8f has a water guide pipe 10 extending upwardly from the preceding immersion tank.
a to 10g are provided, and each of these water conveyance pipes 10a
Pumps P1 to P6 are connected to the pipes P1 to P6, and spray nozzles 11a to 11g are provided at the tips of the pipes corresponding to the upper positions of the tanks, respectively.

A control valve 1 is installed in the water conveyance pipes 10a to 10g.
2a to 12g are provided, and these control valves 12a to 12g are connected to a detector 1 such as a limit switch, as typically shown in the second water washing zone 2B.
3, and is automatically opened and closed in response to an activation signal from the detector 13 caused by the lifting and lowering of the object I to be processed.

Note that, if necessary, a ball tap valve 14 facing the preceding immersion tank may be connected to the water guide pipes 10a to 10g.

In the sixth flush zone 2F, which is the final flush zone, an independent storage tank 8g is provided, and fresh water is stored in this tank via, for example, a pure water device 15, and fresh water is stored in this tank via a pump P7. A new water conduit 10g is extended to the final immersion tank 8f, and the attached water is replaced by a spray nozzle 11g at the tip.

Conventionally, the chemical solution zone 1 is surrounded by a tunnel-shaped booth 26 except for the front and back, and the object to be processed I is transported in that space and is moved up and down intermittently, but in the present invention, As shown in FIG. 2, an evaporation chamber 16 with a required volume is provided at an upper position outside the chemical zone booth via a partition wall 40. This evaporation chamber 16 is a spray nozzle 11a.
This is a dedicated chamber for removing the added amount of washing water that is sent forward in the process, and is not for spraying chemical solutions or washing water onto the objects to be treated. A spray mechanism 17 is disposed within the evaporation chamber 16 . The spray mechanism 17 is connected to the immersion chemical tank 6 by a pipe 18 via a pump P10, and is further connected to the evaporation chamber 1.
A hot air introduction part 19 is provided at a proper position of 6.

The hot air introducing section 19 is connected to a supply source through piping, and specifically, is connected to an exhaust system such as a pretreatment drying furnace 3, a paint baking furnace 5, a deodorizing device, or a chemical solution heating means. This makes effective use of that waste heat.

A flow path is provided in the lower part of the evaporation chamber 16 for returning the unevaporated chemical to the immersion chemical tank 6. On the other hand, an exhaust duct 20 is provided in the upper part of the evaporation chamber 16, and a gas-liquid separator 21 and a load fan 22 are connected to the exhaust duct 20. A return pipe 23 is provided for returning the water.

A heat pump 24 is disposed outside the evaporation chamber 16 as a means for heating the chemical in the immersion chemical tank 6. This heat pump 24 includes a refrigerant evaporator 27 and a condenser 29.
and refrigerant piping 31 that circulates refrigerant between them.
, a compressor 28 and an expansion valve 30 which are connected in the piping.

The load fan 2 is installed inside the refrigerant evaporator 27.
An exhaust duct 20' led from 2 is connected, and an exhaust section 33 is provided elsewhere. In addition, the refrigerant evaporator 27 has an optional water washing zone or water supply tank 8g.
A water recovery pipe 32 is connected thereto.

On the other hand, a pipe 37 equipped with filters 34, 34' and a pump 35 is led out from the chemical solution tank 6 for immersion, and this pipe 37 is connected to the condenser 29 described above. A pipe 37' leading to the immersion chemical tank 6 is connected to the other part of the condenser 29, and these pipes 37, 37' constitute a circulation system between the condenser 29 and the chemical tank 6. .

Next, the operating condition and operation of the device of the embodiment will be explained.

During operation, the object to be treated I is loaded into the chemical zone 1 by the conveyor H, stopped here and immersed in the dipping chemical tank 6, and then pulled up and sent to the first washing zone. In the present invention, when the object to be treated is lifted onto the immersion chemical tank 6, the water led from the immersion tank 8a of the first washing zone is sprayed by the spray nozzle 11a, and then the object is immersed in the immersion tank 8a. As a result, the first stage of water washing is performed. Similarly below,
It is washed from the first washing zone 2A to the second washing zone 2B, and fresh water is sprayed by the spray nozzle 11g before being sent out from the final washing zone 8f.

During the operation as described above, the chemical solution is supplied from the immersion chemical tank 6 via the pump P10 and the piping 18 to the spray mechanism 17 in the dedicated evaporation chamber 16 separately installed in the chemical zone 1. The water is sprayed from the spray mechanism 17 into the evaporation chamber 16 . During this operation, from the hot air introduction section 19 to the evaporation chamber 16
Since hot air is blown into the evaporation chamber 16, the indoor temperature of the evaporation chamber 16 rises, and even if the temperature of the spray liquid is low, it evaporates sufficiently. Since this evaporation chamber 16 is a dedicated evaporation space separated from the chemical processing space in the tunnel-shaped booth, there is a high degree of freedom in its volume, and there is also a high degree of freedom in the amount of spray from the spray mechanism 17. There is also a degree of freedom in the temperature and amount of hot air introduced. Therefore, the amount of water supplied by the spray nozzle 11a from the first water washing zone 2A is reliably removed, and generation of surplus water is suppressed. Furthermore, the efficiency of collecting the chemical liquid mist by the gas-liquid separator 21 is improved, and the amount of heat recovered by the heat pump 24, which will be described later, is small, and the power required for the heat pump is also small. Moreover, when hot air is blown into the booth entrance, it disturbs the airflow inside the booth, sometimes unnecessarily shaking the workpieces suspended and conveyed on a conveyor, or unnecessarily raising the temperature inside the booth. However, in the present invention, the amount of replenishment water can be removed smoothly and reliably without causing this problem.

As described above, the vapor generated in the evaporation chamber 16 is sent to the gas-liquid separator 21 through the exhaust duct 20 by the load fan 22, and the chemical mist contained in the exhaust is removed. The removed chemical solution is returned to the immersion chemical tank 6 through the return pipe 23. The exhaust gas discharged from the gas-liquid separator 21 is further processed by the heat pump 24 to heat the chemical solution and generate washing water.

That is, the exhaust gas exiting the load fan 22 is sent to the refrigerant evaporator 27 of the heat pump 24, where it is cooled by heat exchange with the refrigerant passing through the refrigerant pipe 3, and the air is released from the exhaust section 33.
The steam condenses into water, which is sent to the water supply tank 8g via the water recovery pipe 32. And 10g of piping
fresh water is supplied to the spray nozzle via the spray nozzle. Note that if the water in the water supply tank 8g decreases, fresh water is replenished by the pure water device 15, but in this case as well, the amount of fresh water used can be extremely small.

On the other hand, the chemical liquid in the chemical liquid tank 6 for immersion is transferred to the pipe 3
7, 37' to the condenser 29 of the heat pump 24
It circulates and flows as shown by the arrow in Figure 3. Since the refrigerant heated by the compressor 28 is introduced into the condenser 29 through heat exchange with the steam as described above, the chemical solution is repeatedly heated and returned to the chemical solution tank 6 .

Since the above heating utilizes the latent heat generated by condensation of water, the amount of heating heat sufficiently satisfies the amount of heat required for water evaporation by the spray nozzle for washing with water.
No extra fuel is required to heat the chemical. The present invention evaporates moisture increased by spray water washing not in the booth but in another evaporation chamber 16 adjacent to the booth by spray and hot air, and then removes the chemical mist in the gas-liquid separator 21 via the exhaust duct 20. , the chemical solution is sequentially returned to the chemical solution tank 6 for immersion.
Next, it is cooled by the refrigerant evaporator 27 of the heat pump 24, and the vapor is condensed and returned as washing water.Furthermore, the heat recovered by the heat pump 24 is returned to serve as a heating source for the immersion chemical tank 6.

Therefore, according to the present invention, only a small amount of supplementary fresh water and electric power for operating the heat pump 24 are sufficient to be supplied. Moreover, as mentioned above, since there is a high degree of freedom in the amount and temperature of hot air blown into the evaporation chamber 16, the refrigerant evaporation efficiency is improved, and the heat pump 2
The required power of 4 can also be small. Therefore, it is possible to obtain a surface treatment apparatus that is completely pollution-free and easy to control.

[Effect of idea]

According to the present invention explained above, since surface treatment is performed by sequentially immersing the object to be treated in a chemical solution and washing water,
In addition to the basic effect of providing good surface treatment for objects with complex shapes such as irregularities, the immersion chemical tank 6 is connected by a circulation system with a heat pump 24, and a booth and a partition wall 40 are installed near and above the chemical zone 1. A dedicated evaporation chamber 16 is provided, the upper part of which is connected to the refrigerant evaporator side of the heat pump 24 via an exhaust duct 20. In addition to providing a mechanism 17, a hot air introducing section 19 from the outside is provided.
By providing this, the following excellent effects can be obtained.

It is possible to accurately prevent the generation of surplus water due to the pre-purified water forwarding method.

In other words, the amount of chemical solution increases by washing the treated object I pulled up from the chemical solution tank 6 for immersion with the forward-fed washing water, but as a means for processing this amount of water, a dedicated evaporation chamber separated from the booth is used. 16, the chemical solution is sprayed into this chamber and hot air is blown directly into the room to raise the temperature. This makes the evaporation of water much more effective than spraying the chemical solution inside the booth, and even if the temperature of the chemical solution is low, the temperature can be increased. The amount of make-up water added by feeding can be reliably evaporated, and generation of surplus water can be avoided.

The chemical solution recovery efficiency is improved, and the power required for the heat pump is reduced.

In other words, the chemical solution is sprayed into a dedicated evaporation chamber 16, and hot air is blown directly into the chamber before being sent to the gas-liquid separator 21. Since there is a high degree of freedom in hot air temperature and hot air volume, the chemical solution mist collection efficiency can be improved. gets better. Furthermore, since the amount of exhaust heat from the gas-liquid separator 21 is high, the heating efficiency of the chemical liquid in the refrigerant evaporator 27 of the heat pump 24 is improved, and the temperature of the chemical liquid returned from the gas-liquid separator 21 is also high.
The heat pump including the compressor etc. can be small and have a small capacity.

Does not adversely affect the chemical treatment process.

Evaporation of the pre-fed water volume is carried out by spraying and blowing hot air from a dedicated evaporation chamber 16 that is separate from the booth of chemical zone 1, so that it does not adversely affect the chemical processing in the booth and provides smooth surface treatment. be able to. In other words, it does not disturb the air flow in the booth of the chemical zone, shake the object to be treated, disturb the spraying of pre-purified water, or cause an unnecessary increase in the temperature of the chemical solution.

[Brief explanation of drawings]

Figure 1 is a schematic diagram showing the arrangement of the immersion closed type surface treatment apparatus according to the present invention, and Figure 2 is a
FIG. 3 is a sectional view taken along the line of FIG. 3, and is a system diagram showing the flow of fluid in the present invention. 1... Chemical solution zone, 2A to 2F... Washing zone, 6... Chemical solution tank for immersion, 11a to 11g...
... Spray nozzle, 16 ... Evaporation chamber, 17 ... Spray mechanism, 19 ... Hot air introduction section, 20 ... Exhaust duct, 23 ... Return pipe, 24 ... Heat pump, 26 ... Tunnel booth, 27 ... Refrigerant condenser, 29...Condenser, 32...Water recovery piping, 3
7, 37'... Circulation piping, 40... Partition wall.

Claims (1)

[Scope of utility model registration request] A tunnel-shaped booth is provided with a chemical solution zone 1 and a plurality of washing zones 2A to 2F following the chemical solution zone 1. The chemical solution zone 1 is equipped with a chemical solution tank 6 for immersion containing an aqueous solution containing a chemical agent, and the washing zones 2A to 2F are equipped with a chemical solution tank 6 for immersion containing an aqueous solution containing a chemical agent. The booth has immersion tanks 8a to 8f containing immersion chemicals, and the immersion chemical tank 6 has a booth that suspends the object to be treated.
and a conveyor H that sequentially immerses, pulls up, and transfers the object to be treated in each dipping tank 8a to 8f, and further includes dipping tanks 8a to 8 in the washing zones 2A to 2F.
In the immersion type surface treatment apparatus, the final water washing zone 2F is equipped with a means for replacing the adhesion with fresh water.
On the other hand, an evaporation chamber 16 is provided near and above the chemical zone 1, partitioned by a booth and a partition wall 40, and whose upper part is connected to the refrigerant evaporator side of the heat pump 24 via an exhaust duct 20. An immersion closed type surface treatment apparatus characterized in that a spray mechanism 17 connected to an immersion chemical tank 6 via a pump is provided in an evaporation chamber 16, and a hot air introducing section 19 from the outside is provided.