JPH0114315B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an energy-saving, wastewater-free pretreatment method.

When painting or plating metal products, pre-treatments such as degreasing and chemical conversion to chemically condition the base surface are essential. One of the pretreatment methods is to create multiple zones (chambers) inside the tunnel-like booth.
A method in which a spray mechanism and liquid tank are installed in each zone, and a specified chemical solution is sprayed while the object to be treated is transported by a conveyor, and the chemical solution is washed away by spraying washing water in multiple stages below the next zone. is widely used.

This spray-based pretreatment has the advantage of being fully automated and can be processed in a short time.However, in the past, fresh water was supplied to the liquid tank in each cleaning zone to prevent contamination of the cleaning water, so it was not possible to clean the cleaning water. Disadvantages include the generation of large amounts of hazardous wastewater and the need for complicated and expensive wastewater treatment equipment.

As a countermeasure for this, in Japanese Patent Publication No. 52-27615, etc., each zone is connected with overflow piping, fresh water is supplied to the final washing zone, and the excess amount is sequentially overcrowded into the liquid tank of the previous zone, and the upper part of the chemical liquid zone is A system has been proposed in which the surplus amount is discharged as steam.

However, this system has the following drawbacks because it constantly actively generates surplus cleaning water, sends it to the chemical zone, and exhausts evaporated water from the chemical zone to balance the amount of surplus water.

It is difficult to control the amount of evaporation because it is necessary to change the amount of evaporation depending on the amount of surplus water, and if the balance is disrupted, such as by stopping overflow from a certain liquid tank, a fatal problem will occur.

Because exhaust is required to match the amount of excess water, a fan with a larger exhaust capacity than necessary is required, and a portion of the overflow water exceeds the exhaust capacity and is discharged to the outside, making it virtually impossible to achieve wastewater-free operation. .

Since steam is discharged directly at the chemical zone, spray mist is likely to be brought into the cleaning zone beyond the chemical zone, increasing the contamination of the cleaning water.

The present invention eliminates the drawbacks of the conventional systems of this type as described above, and enables efficient wastewater treatment with a small amount of make-up water without producing surplus water, as well as carrying out spray mist to the downstream zone and reducing the temperature of the chemical zone. This can be easily and reliably prevented, and appropriate energy savings can also be achieved. The present invention aims to provide a wastewater-free pretreatment method.

In order to achieve this objective, the present invention first creates surplus water in the final cleaning zone, supplies this in an overflow manner to the chemical tank, and evacuates the surplus water in the chemical zone, as in conventional systems. An amount of cleaning water corresponding to the water taken out as steam from the chemical zone is replenished by spraying using a bypass pipe that branches from the spray piping to the next cleaning zone, and the amount of water corresponding to the decrease in this cleaning zone is supplied to the next cleaning stage. The spray is replenished from the zone in a similar manner, and the final cleaning zone is sprayed with the necessary amount of fresh water without producing excess water.

This eliminates the problems caused by the surplus water supply system and enables truly effective wastewater-free pretreatment.Moreover, make-up water is supplied from the next stage to the outlet side of the previous stage by a spray method, and the make-up water is sprayed. By using a bypass pipe branched from the feed pipe for the main spray in the next stage, it can be carried out under the same pressure conditions as the main spray despite the small amount of water, which improves the washing efficiency in each zone. Effective pretreatment can be performed with an extremely small amount of make-up water.

Furthermore, the present invention provides a hot air blowing port at the inlet of the chemical zone, from which hot air, for example, waste heat from a drying oven, is continuously blown, and forced exhaust is carried out from the outlet of the chemical zone to the next cleaning zone. This method not only prevents outside air from entering the booth entrance, but also keeps the ambient temperature in the chemical zone high by exhausting hot air across the chemical zone, thereby increasing the temperature of the liquid tank. The fuel ratio of the device is improved. At the same time, the spray curtain in the chemical zone acts as an intake resistor for hot air and steam, creating a negative pressure in the cleaning zone and directing the flow of mist and air in the cleaning zone toward the chemical zone, which prevents overspray and mist from being brought in. This can be reliably prevented and the washing efficiency can be further improved.

Embodiments of the present invention will be described below based on the accompanying drawings.

Figures 1 to 3 show examples in which the present invention is applied to degreasing and chemical conversion coating treatment in metal product painting equipment, where A is the degreasing section, B is the chemical conversion section, C is the coating section, and D is the baking or conversion coating treatment. / and a drying section, E is a conveyor, and F is a processed object.

The degreasing section A and the chemical conversion section B are configured as a tunnel-shaped booth 1, and in this embodiment, the interior of the booth is as follows:
From the processing material charging side, the inlet section (drain zone)
2A, preliminary degreasing zone 2B, degreasing zone 2C, first cleaning zone 2D, second cleaning zone 2E, third cleaning zone (final washing zone) 2F, chemical conversion zone 2
G, 4th cleaning zone 2H, 5th cleaning zone 2I,
A sixth cleaning zone 2J, a final cleaning zone 2K and an outlet section 2L are formed separately, and a preliminary degreasing zone 2B
Boundary zones 2M to 2U for draining liquid are provided between the zones from 1 to the final zone 2K.

From the preliminary degreasing zone 2B to the final cleaning zone 2
Each zone up to K has spray nozzles 3B, 3C, 3D, 3E, 3F, 3G, 3H, 3, respectively.
I, 3J, and 3K are arranged, and liquid tanks 6B to 6B connected to the spray nozzles 3B to 3K via pumps 4B to 4K and feed pipes 5B to 5K are provided at the bottom.
6K is provided.

Each of the liquid tanks 6B, 6C, and 6G in the preliminary degreasing zone 2B, degreasing zone 2C, and chemical conversion zone 2G is provided with chemical solution heating means 7, 7' such as an immersion tube burner or a hot water boiler, respectively. and,
Preliminary degreasing zone 2B and degreasing zone 2C are through pipes 30
and the filters 31, 31',
Circulation system 34 with pump 32 and flotation tank 33
are connected at each end to drain the degreased oil. On the other hand, a circulation system 36 including a sludge filter 35 connects the feed pipe 5G of the chemical conversion zone 2G and the liquid tank 6G.

The degreasing zone 2C, the first cleaning zone 2D, the second cleaning zone 2E, the chemical conversion zone 2G, the fourth cleaning zone 2H, the fifth cleaning zone 2I and the sixth cleaning zone 2J each have a portion on the exit side, that is, in each zone. A replenishment spray nozzle 8 is located from the rear of the spray nozzle to the boundary zone.
D, 8E, 8F, 8H, 8I, 8J, and 8K are arranged.

The replenishment spray nozzle 8D on the outlet side of the degreasing zone 2C is connected to the first cleaning zone 2 by a bypass pipe 9D.
D is moved backward and connected to a feed pipe 5D that connects the liquid tank 6D of the first cleaning zone 2D and the spray nozzle 3D, and similarly, the replenishment spray nozzle 8E of the first cleaning zone 2D is connected to the second cleaning zone by a bypass pipe 9E. The feed pipe 5E of 2E and the replenishment spray nozzle 8F of the second cleaning zone 2E are respectively connected to the feed pipe 5F of the third cleaning zone 2F by a bypass pipe 9F.

Furthermore, the replenishment spray nozzle 8H on the outlet side of the chemical conversion zone 2G is connected to the feed pipe 5H connecting the liquid tank 4H and the spray nozzle 3H of the fourth cleaning zone 2H by a bypass pipe 9H.
The replenishment spray nozzle 8I at H is connected to the feed pipe 5I of the fifth cleaning zone 2I by a bypass pipe 9I.
and the replenishment spray nozzle 8 of the fifth cleaning zone 2I.
J is the sixth cleaning zone 2J by the bypass pipe 9J.
The feed pipe 5J and the replenishment spray nozzle 8K of the sixth cleaning zone 2J are connected to the feed pipe 5K of the final zone 2K by a bypass pipe 9K, respectively.

As mentioned above, in the present invention, make-up water is forwarded using a feed pipe for the main spray nozzle and a branched bypass pipe, and the feed pipe is simply extended to connect the main spray nozzle and the make-up spray nozzle in series. If the replenishment spray nozzle is arranged in the main spray nozzle, the amount of water in the replenishment spray nozzle is much smaller than that in the main spray nozzle, so that the replenishment spray nozzle becomes so-called raindrop-like, and the replenishment spray nozzle cannot form a good mist. If configured as in the present invention, the pump pressure can be effectively used to spray the zone concerned and make-up water spray to the preceding zone under equal pressure conditions, thereby achieving the desired cleaning and dilution effect.

Each of the bypass pipes 9D, 9E, 9F, 9H, 9
I, 9J, 9K are equipped with control valves 10D, 10E, 10F, 1, such as electromagnetic valves, respectively.
0H, 10I, 10J, and 10K are provided, and the control valve 10D of the bypass pipe 9D is activated by a signal from the level switch 11B provided in the liquid tank 6B of the preliminary degreasing zone 2B, and replenishes the amount of water so that no surplus water is generated. Supplied to spray nozzle 8D.
In addition, the control valve 10 of the bypass pipe 9E
E is connected to the level switch 11D provided in the liquid tank 6D of the first cleaning zone 2D, and similarly, the control valve of the bypass pipe 9F is connected to the liquid tank 6E in the previous stage.
The level switch 11E provided in the and the bypass pipe 9
H control valve 10H is chemical zone 2G
The level switch 11G installed in the liquid tank 6G, the bypass pipe 9I connects the level switch 11H of the previous stage liquid tank 6H, the bypass pipe 9J connects the level switch 11I of the liquid tank 6I, and the bypass pipe 9K connects the level switch 11I of the liquid tank 6J. 11J, and the amount of makeup water sprayed is automatically controlled so as not to generate surplus water.

On the other hand, fresh water replenishment spray nozzles 8W and 8X are provided at the outlet positions of the third cleaning zone 2F and the final zone 2K, respectively, and each replenishment spray nozzle 8W and 8X is connected to tap water by external piping 9W and 9X. and pure water are now being supplied. And the replenishment spray nozzles 8W, 8X
3rd cleaning zone 2F and final zone 2 with replenishment from
To prevent excess water from forming in K, pipe 9
Abnormal high water level operation valve 12 for W and 9X respectively
A and an abnormally low water level activation valve 12B are provided, and a high water level level switch 13A and a low water level level switch 13B provided in the liquid tank 6F of the third cleaning zone 2F and the liquid tank 6K of the final zone 2K are electrically connected. It is connected.

The abnormally high water level operation valve 12A is normally open, and is closed by a signal from the high water level switch 13A to stop the water supply and at the same time issue an alarm. The abnormally low water level operating valve 12B is normally closed, and is opened in response to a signal from the low water level switch 13B to supply makeup water and at the same time issue an alarm.

Further, the present invention is directed to the inlet side of the chemical liquid zone, that is, in this embodiment, the preliminary degreasing zone 2B.
An inlet 14 for hot air (waste heat) led from the outside is provided in the inlet section 2A in front of the chemical conversion zone 2A and the boundary zone (hereinafter referred to as inlet section) 2Q in front of the chemical conversion zone 2G, respectively.
14' is provided.

The air inlets 14, 14' are preferably provided in the lower area in the height direction of the booth, and may be configured as simple openings, but may also be slit-shaped or spray-shaped nozzles, and the number of arrangement may be arbitrary. can be,
The placement side can also be freely chosen, such as on one side wall of the booth or on both sides.

The blown hot air may be of any type as long as it has a composition that does not harm the chemical treatment, but from the viewpoint of energy conservation, it is preferable to use the waste heat generated in the pretreatment and subsequent treatment that are the subject of the present invention. It is preferable. In this embodiment, the exhaust gas of the hydrocarbon fuel such as propane used in the baking and/or drying section D,
Chemical solution heating means 7 in the degreasing section A and the chemical forming section B;
Exhaust gas and exhaust air from 7' are used.

That is, specifically, the conduits 16 and 16' are connected to the exhaust system 15 of the baking and/or drying section D,
These conduits 16, 16' are connected to the previous inlets 14, 1 through blowers 17, 17' and control valves 18, 18'.
4', and the exhaust part of the chemical solution heating means 7, 7' is connected to the inlet part 14, 14' through a conduit 16", 16" having a blower 19, 19' and a control valve 20, 20'.
and is connected to the inlet ports 14, 14' via a mixer and a pressure equalizer as necessary. Note that if the hot air temperature is too high, vaporization or thermal decomposition will occur. If the temperature is too high, adjust the temperature preferably to 150-200℃ by taking in some outside air. Further, depending on the gas components, neutralization is performed using a catalyst or the like.

Furthermore, the present invention not only provides the hot air blowing ports 14, 14' at the inlet of the chemical zone as described above, but also provides an area extending from the outlet side of the chemical zone to the next cleaning zone, that is, the suction ratio. For example, the intake portion is provided in a region where the ratio between the chemical solution side and the cleaning side is approximately 5:5 to 6:4. In this example, the degreasing zone 2C
and the first cleaning zone 2D, and the chemical conversion zone 2G and the fourth cleaning zone 2N and the first cleaning zone 2D.
Intake portions 21, 21', 22,
22' are provided, and the intake parts 21 and 22 on the side closer to the chemical liquid zone are connected to the exhaust dust 25 equipped with an eliminator 23 and a load fan 24, respectively, and the intake parts 21' and 22' on the cleaning zone side are connected to the exhaust dust 25, respectively. Eliminator 2 by bypass duct 26
3 and the exhaust duct between the load fan 24 and the load fan 24. The eliminator 23 is provided with a return pipe 27 that reaches the degreasing zone 2C and the chemical formation zone 2G.

The above-mentioned embodiments are merely examples of the present invention, and may be applied to degreasing equipment alone, chemical conversion equipment alone, degreasing/chemical conversion equipment, etc.
This naturally includes the omission of a preliminary degreasing zone and the addition of a hot water washing step and a post-treatment step.

Next, the method and operation of the present invention will be explained.

The workpiece F is suspended by a conveyor E and is conveyed at a predetermined speed from the entrance section 2A to the exit section 2L of the booth 1, and is then transported to a preliminary degreasing zone 2B and a degreasing zone 2C.
A predetermined degreasing agent is sprayed by the spray nozzles 3B and 3C in both zones while passing through the zone, and then the cleaning water is sprayed by the spray nozzles 3D, 3E and 3F while passing from the first cleaning zone 2D to the third cleaning zone 2F. After being sprayed, the highly concentrated chemical solution is washed away. Next, the material to be treated F enters the chemical conversion zone 2G, where it is sprayed with a chemical agent by the spray nozzle 3G to form a film, and then passes through the spray nozzles 3H to 3K of the fourth cleaning zone 2H to the final cleaning zone 2K. The attached chemical solution is washed away by the cleaning water spray.

In such an operation, the present invention provides an injection port 1 provided at the inlets 2A and 2Q of the degreasing section A and the chemical forming section B.
Hot air is continuously blown from the exhaust ducts 25, 25 through the load fans 24, 2 of the exhaust ducts 25, 25.
4 from the exit side of the degreasing zone 2C.
Intake portions 21 and 2 provided over the cleaning zone 2D
The internal atmosphere is sucked and discharged by suction sections 22 and 22' provided from the exit side of the cleaning zone 1' and the chemical conversion zone 2G to the fourth cleaning zone 2H, respectively. Then, in combination with the spraying from the above-mentioned spray nozzle, the degreasing zone 2C, the first cleaning zone 2D, the second
Cleaning zone 2E, chemical conversion zone 2G, fourth cleaning zone 2H, fifth cleaning zone 2I, sixth cleaning zone 2
Replenishment spray nozzle 8 arranged at each outlet part of J
D, 8E, 8F, 8H, 8I, 8J, 8K,
Spray nozzle feed pipes 5D and 5 on the rear stage side, respectively.
Bypass pipes 9D, 9E, 9F, 9H, 9I, 9J, connected to E, 5F, 5H, 5I, 5J, 5K,
Send make-up water through 9K and spray each. Also, fresh water is supplied from external piping 9W, 9X to the replenishment spray nozzles 8W, 8X on the exit side of the final zones 2F, 2K for spraying.

Therefore, in this embodiment, the hot air leads the high-temperature exhaust gas from the baking and/or drying section D and the exhaust gas from the chemical heating means 7 through conduits 16, 16'', mixes them, and supplies them to the blowing port 14. In this way, a high-temperature gas curtain is formed at the inlet of the chemical zone 2B by the jet of hot air from the inlet 14, and this gas curtain blocks the intrusion of low-temperature outside air. Since the suction and exhaust force is working on the exit side of the degreasing zone 2C, the hot air that formed the gas curtain is then forcibly drawn to the degreasing zone 2C, and becomes a flow that crosses the degreasing zone and becomes an intake air. It is sucked from the part 21.

At this time, in the degreasing zone 2C, the spray nozzle 3
Chemical liquid is sprayed by C, but in the past, exhaust was performed by simply taking in a large amount of outside air at the inlet, and the cold processed material entered and exited as it was, so the amount of heat taken out was reduced. It was a lot. However, in the present invention, hot air continuously passes through the degreasing zone 2C to heat the spray mist. This eliminates the previous interruption of outside air intrusion and the removal of heat by the object to be treated, and the drop in temperature of the chemical solution returned to the liquid tank 6C after spraying is significantly reduced. Therefore, the thermal efficiency is improved, the heat source for heating the chemical liquid is required to be reduced to the minimum required amount, and the fuel ratio is significantly improved.

Since the chemical solution is sprayed in the degreasing zone 2C under high temperature conditions, the spray mist is vaporized and becomes steam whose volume has expanded approximately 1500 times. The load fan 24 generates an exhaust air volume that is greater than the amount of steam generated.
, and suction and exhaust is carried out in the area from the outlet side of the degreasing zone 2C to the first cleaning zone 2D. With this exhaust system, the degreasing zones 2B and 2
An amount of water corresponding to the evaporated amount at C and an amount of water corresponding to the amount of spray mist required for the subsequent cleaning zone are discharged, and the discharge ratio of these amounts of water is set in advance at the arrangement position of the intake section. Therefore, in the present invention, the amount of water corresponding to the evaporated content of the degreasing zones 2B and 2C is
The replenishment spray nozzle 8D replenishes from the first cleaning zone 2D in the next stage, and replenishes cleaning water from the second cleaning zone 2E in the next stage to match the decrease in water volume in the first cleaning zone 2D. The third cleaning zone 2, which is the final zone of degreasing section A,
F, and fresh water is replenished to the third cleaning zone 2F only in the required amount so that surplus water does not occur in this zone, that is, in an amount corresponding to the amount of water discharged in the degreasing zones 2B and 2C. In order to simplify the explanation, the amount of water that adheres to the object to be treated and is carried out to the next zone is omitted, but it goes without saying that this amount of water is added to the amount of replenishment water. The makeup water is automatically controlled by a control valve provided in the bypass pipe and a level switch in the liquid tank at the front stage, and fresh water is automatically controlled by high water level and low water level operation valves.

By the way, as mentioned above, if the cleaning water is forwarded from the latter zone and the fresh water is supplied to the final zone by simply injecting it into the liquid tank, no improvement in cleaning efficiency can be expected; If a replenishment spray is attached to the feed pipe, the mist spray effect cannot be obtained because the replenishment water is small. However, in the present invention, a bypass pipe is branched into the feed pipe, and the pump pressure is applied equally to the main spray nozzle and the auxiliary spray nozzle to perform forward spraying.

Therefore, in the degreasing zone 2C, after the chemical solution is sprayed by the spray nozzle 3C from the liquid tank 3C via the feed pipe 5C, before the processed material F enters the next first cleaning zone 2D, the first cleaning zone 2D is The cleaning water sent from the liquid tank 6D through the bypass pipe 9D (the amount of which corresponds to the amount of evaporated water in the degreasing zone) is efficiently delivered to the auxiliary spray nozzle 8D at the same pressure as the spray nozzle in the first cleaning zone 2D. Sprayed. As a result, the chemical solution is diluted before entering the first cleaning zone 2D, and in this state, mist cleaning is performed by the spray nozzle 3D of the first cleaning zone 2D. Then, at the outlet of the first cleaning zone 2D, the makeup water from the second cleaning zone 2E is similarly sprayed by the makeup spray nozzle 8E,
This operation is repeated in each zone, and fresh water is supplied to the spray nozzle 8W at the outlet of the final zone 2F.
sprayed by. Therefore, in the present invention, not only no surplus water is generated, but also 2.
The cleaning efficiency is increased because the cleaning is performed more frequently.

The above is one of the features of the present invention, but simply placing a replenishment spray nozzle at the outlet of each zone or providing an intake section directly in the degreasing zone will result in only vapor being concentrated and being sucked out.
The presence of a make-up spray at the outlet has the negative effect of carrying contaminated water into the next zone.

However, in the present invention, as described above, direct exhaust is not performed in the degreasing zones 2B and 2C;
Since suction and exhaust is performed at the outlet of C and the first cleaning zone 2D following it, the steam generated in the degreasing zones 2B and 2C is drawn along with the blown hot air while facing moderate resistance by the spray curtain in the degreasing zone. Become. As a result, the inside air in the first cleaning zone 2D and subsequent cleaning zones 2E and 2F becomes negative pressure, and the flow of air and spray mist in these zones is directed toward the degreasing zone.
Therefore, even if make-up water is sprayed at the outlet of each zone, the mist will not be carried into the next zone, and the highly concentrated liquid that adheres to the workpiece will be reliably washed away with the mist from the next zone. It can be dropped. Therefore, the degree of contamination of the washing water is reduced,
In addition, hot air is included in the intake air at the intake section 21', and since this bypasses the eliminator 23 and is guided to the exhaust dust 25, the thermal energy of the hot air promotes evaporation of the mist and prevents condensation. can be dissipated into the atmosphere.

The above-mentioned effect is almost the same in the chemical conversion part B as well. In other words, a high-temperature gas curtain is formed by the jet of hot air from the blow-in port 14', which prevents cold mist from entering from the adjacent third cleaning zone 2F, and at the same time prevents chemical conversion by the processed material whose temperature has decreased due to cleaning. A make-up water spray that prevents a temperature drop in zone 2G and does not generate surplus water at the outlet of each zone including chemical conversion zone 2G, and prevents the mist of these make-up water sprays from being brought into the next zone and effectively Prevents condensation.

Next, specific examples of the method of the present invention will be shown.

Continuous degreasing and chemical conversion treatment of metal products was carried out according to the flow shown in FIG. The object to be treated is the surface area
0.15m ² / piece of automobile parts, this is 2000 pieces / hour
It was treated at a rate of An alkaline degreaser was used for degreasing, and a zinc phosphate-based chemical agent was used for chemical conversion, and the liquid was heated to 50°C using an immersion tube burner (degreasing) and a hot water boiler (chemical conversion).

The inlet ports 14, 14' are connected to the inlet section 2A of the degreasing section.
and the front zone of the entrance section 2Q of the chemical conversion section, respectively, and during operation, a mixed gas of waste gas from the baking drying furnace and waste gas from the immersion tube burner is supplied to the former.
A mixed gas of waste gas from the baking drying furnace and waste heat from the hot water boiler was fed to the latter. The waste heat of the baking drying oven is 250℃, which is reduced to 110℃ by taking in outside air.
×30NM ³ /min, waste heat from immersion tube burner
Mix at 300℃×30NM ³ /min and inject from the inlet.
Blow was carried out at 180°C x 55NM ³ /min at a pressure of 100mmAq.
The waste heat from the hot water boiler is 300°C x 30NM ³ /min, and this is mixed with the waste heat from the baking drying oven, which produces 115
The outside air temperature blown in at ℃×30NM ³ /min and pressure 100mmAq is 20℃.

The intake portions 21, 21', 22, and 22' have an intake ratio of chemical zone side: cleaning zone side = approximately 6:4.
The boundary zone 2N between the degreasing zone and the first cleaning zone and the first cleaning zone 2
D, boundary zone 2Q between chemical conversion zone 2G and fourth cleaning zone 2H and fourth cleaning zone 2
Provided at H, limit load fan nominal capacity
115M ³ /min×140mmAq (degreasing), 132M ³ /min
Exhausted with ×160mmAq (Kasei).

The amount of water discharged by the suction parts 21 and 21' of the degreasing section is approximately 220/H (degreasing zone 180/H,
In the water washing zone (40/H), the amount of water taken out due to adhesion of the objects to be treated was 30/H. Therefore, 210
/H washing water was sprayed from the liquid tank of the first washing zone 2D to the outlet of the degreasing zone via the bypass pipe 9D by the replenishment spray 8D. Also the first
250/H is replenished at the outlet of the cleaning zone 2D by the bypass pipe 9E and the replenishment spray 8E, and the replenishment spray 8W is supplied at the outlet of the third cleaning zone 2F.
Sprayed tap water at 250/hour. The amount of water discharged from the intake sections 22 and 22' of the chemical conversion section is 180
/H (chemical zone 160/H, cleaning zone 20
/H), the amount of water brought in due to adhesion and the amount of water taken out are offset, so the 180/H cleaning water is transferred from the liquid tank of the fourth cleaning zone 6H to the bypass pipe 9H,
The replenishment spray nozzle 8H sprays the outlet of the chemical conversion zone, and the following equal amount of cleaning water is transferred from the latter liquid tank through the bypass pipe and the replenishment spray nozzle.
The water was sequentially sprayed at the outlet of the front zone, and the final cleaning zone was sprayed with pure water at 180/h.

As a result of the above operations, the total amount of replenishment water is 430/hour.
This is approximately 1/20th of the case when fresh water is replenished in each zone, and 1/2 to 1/3 of the case when fresh water is left in excess at the final zone and is sent forward to the overflow or overspray system. Ta. The amount of degreaser used is 1/3 to 1/4, and the amount of chemical agent used is 20% to 1/4.
It decreased by 30%, and the degreasing condition and chemical conversion coating condition of the treated object were also good.

In addition, the indoor temperature of degreasing zone 2C is 50±5
℃, the indoor temperature of the chemical conversion zone 2G was stably maintained at 50±1℃, and the fuel ratio was about 3/5 of that without employing the present invention.

According to the present invention as described above, a chemical solution zone and a plurality of cleaning zones following the chemical solution zone are formed in the tunnel booth, and in the method of transferring the treated material to these zones and performing treatments such as degreasing or 1 and chemical conversion, each In addition to providing a liquid tank in each zone and a mechanism for guiding and spraying chemical solution or cleaning water from this liquid tank through a feed pipe, a replenishment spray mechanism is provided at the outlet side of each zone, and the replenishment spray mechanism in the final zone is used as a fresh water supply pipe. At the same time, connect other replenishment spray mechanisms with a bypass pipe connected to the feed pipe in the subsequent stage,
In addition, we installed a hot air inlet introduced from the outside at the inlet in front of the chemical zone, and also installed a suction/exhaust section from the outlet of the chemical zone to the next zone. The air is blown into the front inlet and sucked and exhausted in the area extending from the outlet of the chemical zone to the next zone, while being replenished from the rear liquid tank to the front outlet via a bypass pipe that branches off the feed rate for the main spray nozzle. I sprayed only the minimum amount of water necessary, so
It prevents the temperature drop in the chemical solution zone and significantly reduces the thermal energy used to heat the chemical solution.At the same time, it uses an extremely small amount of water without producing excess water, and also prevents mist from being brought in by hot air suction, which has a high water washing efficiency. It is possible to perform complete wastewater treatment. In particular, since the waste heat from the baking drying oven and chemical heating means can be effectively used as hot air, excellent effects such as achieving appropriate energy savings and reducing processing costs can be obtained.

[Brief explanation of drawings]

FIG. 1 is a plan view schematically showing an embodiment of the energy-saving non-wastewater pretreatment method according to the present invention;
The figure is a vertical side view schematically showing the degreasing/forming section in FIG. 1, and FIG. 3 is a vertical cross-sectional front view of the inlet of the degreasing section in FIG. 2. 1...Booth, 2A, 2Q...Entrance, 2B,
2C, 2G...chemical zone, 2D, 2E, 2F,
2H, 2I, 2J, 2K...Washing zone, 3B~
3K...Spray nozzle, 5B~5K...Feed pipe, 6B~6K...Liquid tank, 8D, 8E, 8F, 8
H, 8I, 8J, 8K, 8W, 8X...Replenishment spray, 9D, 9E, 9F, 9H, 9I, 9J, 9
K...bypass pipe, 14,14'...inlet,
21, 21', 22, 22'...Intake part.

Claims (1)

[Claims] 1. A method in which a chemical solution zone and a multi-stage cleaning zone following the chemical solution zone are formed in a tunnel booth, and an object to be treated is transferred to these zones for degreasing or treatment such as 1 and chemical conversion. A liquid tank and a mechanism for guiding and spraying chemical solution or cleaning water from this liquid tank via a feed pipe are installed, and a replenishment spray mechanism is installed at the outlet side of each zone, and the replenishment spray mechanism of the final zone is connected to the fresh water supply pipe. On the other hand, the other replenishment spray mechanisms are sequentially connected to the feed pipes at the later stages by bypass pipes, and furthermore, an inlet of hot air introduced from the outside is provided at the inlet in front of the chemical liquid zone.
Using a device that has a suction/exhaust section extending from the exit side of the chemical zone to the next zone, during operation, hot air is blown into the inlet section in front of the chemical zone, and the amount of evaporated water is measured while the generated steam is discharged together with the hot air by the suction/exhaust section. It is characterized by spraying an amount of water commensurate with the amount of water from the next zone to the next zone, then spraying an amount of water commensurate with the decrease in water amount in this zone from the next zone, and spraying only the necessary amount of fresh water without creating surplus water in the final zone. An energy-saving, wastewater-free pretreatment method. 2. The energy-saving non-wastewater pretreatment method according to claim 1, which utilizes waste heat from a drying furnace, baking furnace, chemical solution heating means, etc. as the hot air. 3. The energy-saving non-wastewater pretreatment method according to claim 1, wherein the chemical zone is a degreasing zone. 4. The energy-saving non-wastewater pretreatment method according to claim 1, wherein the chemical zone is a chemical conversion zone. 5. The energy-saving, wastewater-free pretreatment method according to claim 1, wherein the chemical zone is a degreasing and chemical conversion zone.