JPS60135588A - Waste water-less type surface treating device - Google Patents

Abstract

PURPOSE:To provide a titled surface treating device which reduces a fuel cost and uses the simultaneously obtd. condensate as washing water by the constitution in which moisture is evaporated by spraying of liquid chemicals and liquid chemical tanks can be heated by the heat recovered from the waste gas thereof by a heat pump. CONSTITUTION:A material F which is to be treated and is hung to a conveyor E is moved from the left toward the right in each zone and is defatted and washed. The material F is preliminarily washed by an auxiliary spray nozzle 8D near the boundary between a defatting zone 2C and a boundary zone 2N in the stage of transferring from the zone 2C to the 1st washing zone 2D and is conducted to the zone 2D after dewatering. The water of the nozzle 8D is dropped into a liquid tank 6C and in succession, the material is preliminarily washed 8E, 8F in the inlet of respective boundary zones 2O, 2P in the stage of transferring from the zone 2D to the 2nd and 3rd washing zones 2E, 2F and thereafter the material is transferred to the succeeding stage. On the other hand, the liquid chemicals in liquid tanks 6, 6B are heated by fuel and the moisture evaporated when said liquids are sprayed in evacuated 10 by a fan 9. The liquid chemical mists are returned to the liquid chemical tanks. The waste gas emitted from the fan 9 is condensed by the refrigerant of a heat pump 32 and the liquid chemicals in the zones 2B, 2C, 2G are heated by the heat generated by such condensation. The evaporation heat of the water is thus supplied.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spray type surface pretreatment device.

When forming a film such as painting or plating on leftover products, it is essential to pre-treat the base surface by chemically degreasing and converting it. One of the metal surface pretreatment methods is to divide the inside of a tunnel-shaped booth into multiple zones, and install a spray mechanism and a liquid tank in each divided zone, and spray degreasers, chemical agents, etc. while transporting the treated object on a conveyor. A commonly used method is to spray a chemical solution and then spray wastewater in multiple stages below the next zone to wash the chemical solution away.

However, in the conventional spray-type Kanetung surface treatment method, the sprayed chemical solution was stored in a liquid tank and circulated, and fresh water was supplied to each washing monk in order to prevent wastewater contamination. It has the disadvantage of generating toxic wastewater and requiring expensive wastewater treatment equipment.

As a countermeasure against this, one of the inventors of the patent application No. 52-27615 and the present application proposed
-204858, Japanese Patent Application No. 57-216182, V
+! jm No. 57-216183) There is a Shidakata L nato. These methods supply fresh water to the final stage of the flushing zone, and send the resulting surplus water to the preceding flushing zone one after another.
Excess water in the first stage water washing zone is transferred to the chemical spray zone in the preceding stage, and in the chemical zone, the chemical tank is heated to prevent excess water from being generated, the water is evaporated by the chemical spray, and the water is exhausted by a fan. . In these methods, the latent heat due to evaporation of water is mainly provided by the fuel (propane) used to heat the oak liquor tank. This fuel cost is a major factor.

The present invention saves fuel costs by collecting heat from the exhaust gas using a heat pump to heat the mulberry liquid tank, and at the same time saves fuel costs.
A raft circulates the water released by the vertical movement of steam as a water barrier.
It provides a way to conserve tap water.

This will be explained with reference to an embodiment. Figures 1 and 2 show an example in which the present invention is applied to degreasing and chemical conversion coating treatment for metal product coating films (d1), where A is the degreasing part, B is the chemical conversion part, C is the painted part, and D is a baking and/or drying section, E is a conveyor, and F is an object to be treated. Absorbent cotton A and chemical conversion section B are configured as a tunnel-shaped booth 1, with an entrance section 2A, a preliminary degreasing zone 2B, a degreasing zone 2C, and a 1 washing zone 2D, 2nd washing zone 2E, 6th washing zone (final washing zone) 2F, chemical conversion zone 2G, 4th washing zone 2H,
5th flush sea 721. A sixth water washing zone 2J, a final washing zone 2, and an outlet 2L are formed separately, and boundary zones 2M to 2Ub' for draining water are provided between each zone from the preliminary degreasing zone 2B to the final washing zone 2K. .

FIG. 6 is a detailed view of the degreasing section (FIG. 1A).

In FIG. 6, the chemical formation part (B in FIG. 1) is omitted. The degreasing section has two stages of degreasing zones, while the chemical formation section has one stage of chemical conversion zone, and the main degreasing section has six stages of washing zones, while the water washing zone of the chemical formation section has six stages. 4
Other than the step-up structure, the degreasing section and the chemical forming section have exactly the same equipment and operations, so only the function of the degreasing section will be explained below.

Each zone from the preliminary waste removal zone 2B to the sixth washing zone 2F has spray nozzles 3B, 3C,
3D, 3E, and 3F are installed, and a liquid tank 6 is installed at the bottom.
B to 6F are provided. The liquids in the liquid tanks 6B-6F are sent to the spray nozzles 3B-3F through the discharge pipes 5B-5F by pumps 4B-4F, respectively. The liquid tank 6B and the liquid tank 6C are connected by a passage pipe 30, and are also connected to filters 31, 31', a pump 32, and a floating tank 3 for oil and fat.
A tang area thread 34 equipped with 3 is connected to discharge the degreased oil.

In the degreasing zone 2C, first washing zone 2L), and second washing zone 2E, replenishment spray nozzles 8D, 8E, and 8F are arranged at the respective outlet locations, that is, from the rear of the spray nozzle in each zone to the boundary zone. has been done. The replenishment spray nozzle 8D on the outlet side of the degreasing zone 2C is connected to the first washing zone 2 by a bypass pipe 7D.
D is moved backward, and connected to the discharge pipe 5D of the pump 4D. Similarly, the replenishment spray nozzle 8E of the first flush zone 2D is connected to the discharge pipe W5EK of the pump 4E through the bypass pipe 7E, and the replenishment spray nozzle 8F of the second flush zone 72E is connected to the discharge pipe 5D of the pump 4D. Bypass W7
F to the discharge pipe 5F of the pump 4F.

Each bypass pipe 7D, 7E, 7F is provided with an electromagnetic control valve (not shown), respectively.

The control valve of the bypass W7D is activated by a signal from a level switch (not shown) provided in the liquid tank 6B of the pre-degreasing zone 2B, and supplies water to the replenishment spray nozzle 8D in an amount that does not generate surplus water. Similarly, bypass t7
The control valve E is connected to the previous water tank 6DK, tS (digital level switch (not shown)), and bypass pipe 7.
The control valve F is actuated by a signal from a level switch (not shown) provided in the water tank 6E in the previous stage to automatically control the amount of water to be supplied. On the other hand, an 'IJT fresh water supply spray nozzle 8W is provided at the exit position of the third water washing zone 2F, and υf fresh water is supplied from the pipe 7W. Piping γ
An electromagnetic control valve (not shown) is provided in the middle of W and is controlled by a level switch (not shown) of the water tank 6F, so that the water level of the water tank 6F is always kept constant.

In this apparatus a, the objects to be processed are suspended on a conveyor E, transferred from left to right through each zone of the booth 1, and are degreased and washed with water. When the workpiece is transferred to either the degreasing zone 2C or the first washing zone 2D, it is preliminarily washed near the boundary between the degreasing zone 2C and the boundary zone 2N with an anti-water spray from the replenishing spray nozzle 8D, and then drained in the boundary zone 2N. Enter the first washing zone 2D. The water from the replenishment spray nozzle 8D flows downward and enters the liquid tank 6C. Subsequently, when moving from the first washing zone 2D to the second washing zone 2E, and when moving from the second washing zone 2E to the sixth washing zone 2F, the boundary zone 2
Refill spray nozzle 8E, 8F with population of 0, 2P
It is pre-washed with water and moved to the next stage. Refill spray nozzle 8g
, The water on the 8th floor flows down to the water tank 6D in the previous stage.
, enter 6E. In this manner, the washing effect is significantly improved by preliminarily washing the object before moving to the subsequent washing zone. That is, when the object to be processed is transferred from the degreasing zone 2C to the first washing zone 2D, if the object is moved with the chemical solution still attached, the water in the first washing zone 2D will be heavily contaminated. When moving to the first washing zone 2D, preliminary washing is performed and the preliminary washing water enters the liquid tank 6C, so that the amount of dirt in the washing water in the first washing zone 2D is significantly reduced. When moving from the first flush zone 2D to the second flush zone 2E, also from the second flush zone 72E to the sixth flush zone 2.
The same applies when moving to F.

Since the washing water is less contaminated in this way, the amount of water transferred from the water tank 6F to the water tank 6E, from the water tank 6E to the filtered water 461), and from the water tank 6D to the liquid tank 6C is small, so the amount of water in the fresh water supply spray nozzle 8W is small. less.

Water from the replenishment spray nozzle 8D may enter the liquid tank 6C, and the amount of liquid in the liquid tanks 6C and 6B will gradually increase. Conventionally, chemical solution heating devices 6B and 6CK were provided to heat the chemical solution to 5D to 60°C using fuel, and spray nozzles 3B and 3
At the same time as degreasing, water evaporation was measured by the chemical spray C, and the amount of water was evaporated to match the amount of water added by the replenishment spray nozzle 8D. The generated steam is sucked into an exhaust duct 10 by a fan 9 and exhausted. An eliminator 11 is provided in the middle of the exhaust duct 10 to remove chemical mist contained in the exhaust. The removed chemical liquid is returned to the chemical liquid tank through the return pipe 12.

Previously, the exhaust gas was simply dumped into the atmosphere.

In addition, a large amount of fuel was required to heat the chemical solution.

In the present invention, the exhaust gas leaving the fan 9 enters the heat exchanger 13.

The heat exchanger 13 is an evaporator of a heat pump, and the exhaust gas and the refrigerant exchange heat. 14 is a heat pump compressor, 15 is a condenser, 16 is an expansion valve, and arrow 17 is the refrigerant circulation direction. The exhaust air is cooled in the evaporator 13 and the steam condenses into water which enters the water tank 19 through the pipe 18. The pipe 7W comes out from the water tank 19 and supplies fresh water to the replenishment spray nozzle 8WK. That is, the anti-water will circulate through this treatment device. If the water in the water tank 19 decreases, tap water is replenished through the pipe 20, but the amount of tap water used can be extremely small.

The circulation system 34 of the liquid tanks 6B and 6C flows in accordance with the arrow 21 after passing through the flotation tank 33, is heated by the condenser 15 of the heat pump, and returns to the liquid tank 6C. This heating heat it sufficiently satisfies the amount of heat required for water evaporation by the spray nozzles 3B and 3C, and no extra fuel is required.

In this manner, in the apparatus of the present invention, the exhaust gas discharged into the scarlet vapor duct 10 is removed from the chemical mist by the eliminator 11 and returned to the chemical liquid tank 6C, and then cooled by the evaporator 13 of the heat pump to produce steam. The condensed water is returned to the water tank, and the heat recovered by the heat pump is returned to serve as a heating source for the liquid tanks 6B and 6C, resulting in extremely large effects. That is, according to the present invention, only supplementary tap water and electric power for operating the heat pump are sufficient to be supplied, making it possible to obtain a metal surface pretreatment device that is completely pollution-free and easy to control. can.

In addition, in the case of metal product painting equipment, there is equipment for baking and/or drying after painting. Since the heat of this equipment is naturally high temperature, if the temperature is adjusted by mixing outside air into the exhaust air and then blowing from the inlet part 280 and air supply hole 23 through the duct 22, the pre-degreasing zone 2B and the degreasing zone 2C can be heated. The ambient temperature increases and the water evaporates sufficiently even if the spray liquid temperature is somewhat lower. Therefore, there are effects such as the amount of heat recovered by the heat pump being small and the power of the heat pump being small, but these can also be achieved within the scope of the present invention.

As a specific example, if the fresh water from the replenishment spray nozzle 8W is 20017H, that is, the moisture # generated in the preliminary degreasing zone 2B and the degreasing zone 2C is 20 [311AL], the power of the heat pump compressor is approximately 35 KW,
The supply of tap water was also sufficient at 40 l/h. Fuel tank 6B
In the case of the method of heating 6C, 15% of propane was required as fuel, and 200 tJA of tap water was also required.

[Brief explanation of drawings]

Fig. 1 is a general conceptual diagram of a metal product coating equipment to which a wastewater-free metal surface treatment apparatus according to an embodiment of the present invention is applied, Fig. 2 is a front view of the entrance of the degreasing section shown in Fig. 1, and Fig. 6 is a FIG. 3 is a vertical side view of the degreasing section shown in the figure. A... Degreasing section, B... Chemical forming section, C... Candying section, D
... Baking and/or drying section, E... Conveyor, F.
...Workpiece, 1...Booth, 2 people...Entrance, 2
B, 2C. 2G...Medical solution zone, 2D~2F, 2H~2K...
Washing zone, 2M to 2U... Boundary zone for draining, 3
B~3F...Spray nozzle, 4B~4F...Bong 7', 5B~5F...Pump discharge pipe, 6B, 6
C...Liquid tank, 6D~6F...Aquarium, 7D~7F...
・Bypass pipe, 8D to 8F...Replenishment spray, 9...
・Exhaust fan, 10...Exhaust duct, 11...Eliminator-113...Condenser, 14...Compressor, 1
5... Condenser, 16... Expansion valve, 17... Refrigerant circulation arrow, 18... Condensed water return pipe, 19... Water tank,
20...Water pipe, 30...Communication pipe, 31, 31'
...filter, 32...bonder, 33...flotation tank, 34...liquid circulation system.

Claims (1)

[Claims] In an apparatus that forms a chemical solution zone and a multi-stage water washing zone following the chemical solution zone in a tunnel-shaped booth, and transfers the processed material through these zones to perform treatments such as degreasing and/or chemical conversion,
Each zone is equipped with a liquid tank and a mechanism that guides and sprays chemical solution or waste water from this liquid tank, supplies fresh water to the final stage of the washing zone, and sends a portion of the water from the final stage to the previous washing zone. , a part of the water in the first stage water washing zone is sent to the chemical zone, the water is evaporated by the spray mechanism of the chemical zone, and the water is discharged through the exhaust duct, and the exhaust gas is cooled by the refrigerant evaporator of the heat pump and then disposed of. On the other hand, the heat pump heats the chemical solution in the chemical zone using the heat generated by the condensation of the refrigerant, supplies all or part of the heat equivalent to the heat of evaporation of water, and continues evaporation without or with a small amount of fuel. No-waste type % type %