JP3112608B2 - Apparatus and method for treating waste liquid and water-soluble waste paint - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for treating a waste liquid containing a waste liquid and a water-soluble waste paint, and more particularly, to a processing apparatus and a method for drying and treating a waste liquid or a water-soluble waste paint. .

[0002]

2. Description of the Related Art Surface treatment with a degreasing agent is performed in a pretreatment for applying a coating to a metal molded product by press working or the like. The solution containing a degreasing agent containing caustic soda or the like as a main component used in this treatment is discarded as a waste liquid after completion of the treatment. Further, water-soluble waste paints generated during painting are also discarded as waste liquid. Conventionally, the treatment of this kind of waste liquid has been roughly divided into two methods. First, there is a method of chemically treating. In this method, a neutralizing agent is added to a waste liquid containing a degreasing agent to adjust the pH, and then a polymer flocculant is charged to float or separate the waste liquid. The separated water is filtered until it reaches the legal standard and then discharged from the drain.The separated solid is passed through a dehydrator to squeeze out the water and deliver it to the industrial waste disposal company as solids. Was. On the other hand, the second method of the waste liquid treatment is a physical treatment method in which water in the waste liquid is vaporized by heating to make only the solid content.
This method mainly used a drum dryer. The drum dryer mainly includes a cylindrical drum and a water tank provided below the drum, and the lower end of the drum is disposed so as to be immersed in the waste liquid in the water tank. Then, the water tank is filled with waste liquid, the drum is heated by a heating medium such as steam, and the drum is rotated, whereby the waste liquid adhering to the drum surface is dried as the drum rotates, and the dried solid content on the drum surface is removed. Only solids were collected by scraping off with a knife arranged parallel to the drum, and the solids were delivered to a processor.

[0003]

At present, there is a tendency that wastewater discharged from a factory is not allowed to be discharged from a drain port due to a law or the like. For this reason, in the above-mentioned method using the first polymer flocculant, it is necessary to store the separated water in a waste liquid tank and have the waste water collected by a processing company as industrial waste. The method of requesting the processing company to treat the waste liquid increases the cost due to the necessity of paying a treatment fee according to the amount of the waste liquid, and a method of gradually drying the above-described waste liquid to make it into a solid material and taking it to the processing company is required. It is being adopted. However, the method of treating the waste liquid using the drum dryer has a problem that the cost of the waste liquid treatment is low but the fuel cost for drying the waste liquid increases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to provide an apparatus and a method for treating a waste liquid and a water-soluble waste paint in which the cost of drying treatment is reduced.

[0005]

In order to achieve the above-mentioned object, a waste liquid and water-soluble waste paint treatment apparatus according to the present invention comprises, in a first aspect, a heating tank for waste liquid or water-soluble waste paint; A spray chamber for deriving and spraying and vaporizing waste liquid or water-soluble waste paint in the spray tank, wherein the non-vaporized waste liquid or water-soluble waste paint is returned to the heating tank again. A drying chamber for deriving and drying waste liquid or water-soluble waste paint in the heating tank, and a heating device for heating the heating tank by heat generated when burning fuel; The generated exhaust gas in the spray chamber
It is characterized by comprising a heating device for performing vaporization and drying in the drying chamber . Further, in order to achieve the above object, the waste liquid and water-soluble waste paint treatment apparatus according to the second aspect of the present invention includes a waste liquid or water-soluble waste paint heating tank, and a waste liquid or water-soluble waste paint in the heating tank. A spray chamber for spraying and vaporizing the paint, wherein the spray chamber is configured such that the waste liquid or the water-soluble waste paint that has not been vaporized returns to the heating tank again, and the waste liquid or the water-soluble waste paint is dried. A drying chamber for discharging waste liquid or water-soluble waste paint collected in the drying chamber to a waste liquid and a water-soluble waste paint processing apparatus, and a heat generated when fuel is burned. A heating device for heating a heating tank , wherein the exhaust gas generated during combustion evaporates in the spray chamber and dryness in the drying chamber.
A heating device for performing drying and a waste liquid pumping device for pumping waste liquid or water-soluble waste paint from the heating tank to the spray chamber and the drying chamber, wherein the waste liquid or water-soluble waste paint is pumped and vaporized into the spray chamber. And a waste liquid pumping device for pumping the waste liquid or the water-soluble waste paint into the drying chamber while increasing the concentration of the waste liquid or the water-soluble waste paint. Further, in order to achieve the above object, the waste liquid treatment method of the present invention comprises the steps of: heating a waste liquid or a water-soluble waste paint stored in a heating tank by burning fuel with a heating device; simultaneously spraying the sex waste paint, the heating device the spray
Vaporizing the exhaust gas, returning the non-vaporized waste liquid or water-soluble waste paint to the heating tank to increase the concentration of the waste liquid or the water-soluble waste paint; and the waste liquid or the water-soluble concentrate concentrated by the step of increasing the concentration. Pumping the waste paint into a drying chamber and introducing exhaust gas from the heating device to dry the waste liquid or water-soluble waste paint.

[0006]

According to the waste liquid and water-soluble waste paint treatment apparatus of the present invention having the above structure, in the first aspect, the waste liquid is heated in a heating tank, and the heated waste liquid is led out to a spray chamber and sprayed. The concentration of the waste liquid is increased by returning the vaporized, non-vaporized waste liquid to the heating tank again. On the other hand, the heated waste liquid in the heating tank is led to a drying chamber and dried. Heating device to burn the fuel with heat the the heating chamber, the exhaust generated during combustion, and drying in in vaporization and drying chamber for spraying chamber mentioned above. Further, in the waste liquid and water-soluble waste paint treatment apparatus of the present invention having the above-described configuration, in the second aspect, the waste liquid is heated in a heating tank, and the heated waste liquid is fed to a spray chamber by a waste liquid pressure-feeding device. Then, the waste liquid which has not been vaporized is returned to the heating tank again to increase the concentration of the waste liquid. Then, when the concentration of the waste liquid is increased, the waste liquid heated in the heating tank is pumped to a drying chamber by a waste liquid pumping device to be dried. Heating device to burn the fuel with heat the the heating chamber, the exhaust generated during combustion, and drying in in vaporization and drying chamber for spraying chamber mentioned above. Then, the carrying-out means carries out the waste liquid or the dried product of the water-soluble waste paint accumulated in the drying chamber to the outside of the waste liquid and water-soluble waste paint processing apparatus. Further, in the waste liquid treatment method of the present invention having the above configuration, the fuel is burned by the heating device to heat the waste liquid stored in the heating tank. Then, the heated waste liquid is sprayed in the spray chamber, and at the same time, the spray is vaporized by the exhaust of the heating device , and the waste liquid that has not been vaporized is returned to the heating tank to increase the concentration of the waste liquid. Thereafter, the concentrated waste liquid is pressure-fed to a drying chamber, and the exhaust of the heating device is introduced to dry the waste liquid.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration of an apparatus for treating waste liquid and water-soluble waste paint according to a first embodiment of the present invention. The waste liquid and water-soluble waste paint treatment apparatus according to the first embodiment includes a casing 60 having a substantially cubic shape and a thickness. The thick portion of the casing 60 includes a heat insulating material such as asbestos. Are arranged to improve the thermal efficiency and protect the external workers from burns and the like. Inside the housing 60, a heating tank 10 for storing and heating the waste liquid and a spray chamber 20 for spraying and vaporizing the waste liquid are provided.
And a drying chamber 30 for drying the waste liquid. A pan 32 for storing the dried waste liquid is placed in the drying chamber 30. Above the pan 32, a through hole 102 for introducing outside air into the housing 60 is provided.

[0008] Between the heating tank 10 and the spray chamber 20,
An opening plate 66 having an opening 66a for returning the non-vaporized waste liquid to the heating tank 10 side is provided.
Between the spray chamber 20 and the drying chamber 30, a partition plate 62 pointing upward and a partition plate 64 pointing downward are arranged, and configured to allow exhaust gas to pass through as described later. A pump 40 for pumping waste liquid in the heating tank 10 is provided below the heating tank 10. Pump 4
A pipe 41 is attached to the feed side of the pipe 0, and a pipe 46 on the side of the spray chamber 20 is connected to the pipe 41 via a joint 42, and a sprayer 46a is attached to a tip of the pipe 46. . The joint 4
A pipe 44 on the drying chamber 30 side is connected to 2, and a distal end portion 44 a of the pipe 44 is bent so as to face the pan 32 side.

A gas burner 50 connected to a gas cylinder (not shown) for heating the waste liquid in the heating tank 10 by burning an LPG gas or the like is disposed on a side of the heating tank 10. An exhaust pipe of the gas burner 50 is provided. The opening 52 a is guided to the drying chamber 30 and the opening 52 a is arranged so as to heat the pan 32. Although not shown here, the pan 3 is located between the opening 52 a of the exhaust pipe 52 and the pan 32.
A heating plate for efficiently warming 2 is provided. A hatch (not shown) is provided on the side of the pan 32.
The pan 32 can be easily replaced when the waste liquid dries and accumulates in a certain amount or more. On the other hand, an eliminator (filter) 74 is provided above the spray chamber 20 to prevent powdery solid matter generated when the waste liquid is vaporized from leaking to the outside. Is provided with an exhaust device 70 having a fan 72 for discharging water vapor to the outside.

Next, the operation of the apparatus for treating waste liquid and water-soluble waste paint according to the first embodiment will be described. Before the waste liquid treatment by the waste liquid and water-soluble waste paint treatment apparatus of the present embodiment, particles (such as suspended matter) in the waste liquid are removed.
This is to prevent damage to the pump 40 and the like as described later. The waste liquid used for treating the surface of the coated metal is guided to a precipitation tank (not shown), and the abrasive having a high specific gravity (consisting of particles such as aluminum) in the waste liquid is precipitated. The precipitated substance is scraped out by a "spatula" of a conveyor, and water is centrifuged by a well-known technique or heated by a heating device (not shown) to form a solid. In parallel with this treatment, the water from the precipitation tank is introduced into the heating tank 10 of the apparatus for treating waste liquid and water-soluble waste paint shown in FIG. 1 by a pump (not shown). Alternatively, water-soluble waste paint generated during painting is introduced into the heating tank 10. Next, the gas burner 50 is ignited and the heating tank 1 is ignited.
The waste liquid in 0 is heated to 50 degrees or more, preferably to about 70 to 100 degrees. Then, the pump 40 is started, and the heated waste liquid in the heating tank 10 is sprayed by the sprayer 46a of the spray chamber 20.
And sprayed from the sprayer 46a. On the other hand, as described above, the exhaust gas from the gas burner 50 is guided to the drying chamber 30 via the exhaust pipe 52, and is introduced into the spray chamber 20 through the space between the pair of partition plates 62 and the partition plate 64. By the heat of the exhaust gas, the mist-like waste liquid sprayed from the sprayer 46a is heated and vaporized. The vaporized moisture is radiated to the outside from the exhaust device 70 as water vapor by the fan 72 of the exhaust device provided in the upper part of the spray chamber 20. On the other hand, the waste liquid not vaporized returns to the heating tank 10 again through the opening 66a of the opening plate 66. By the vaporization of the waste liquid in the spray chamber 20, the concentration of the waste liquid in the heating tank 10 is gradually increased.

On the other hand, the waste liquid pumped by the pump 40 is also sent to a pipe 44 on the drying chamber 30 side, where
Is dropped onto the pan 32 from the tip 44a of the pan. Bread 3
2 is heated to about 400 to 500 degrees by the exhaust from the gas burner 50 as described above, and the dropped waste liquid is heated in the pan 32 to evaporate the moisture, and only the solid (sludge) is removed from the pan. 32. At a timing when a predetermined amount of solid matter of the waste liquid in the pan 32 is accumulated,
An operator takes out the bread 32 from the waste liquid and water-soluble waste paint processing apparatus, and treats the solid matter in the bread 32 as industrial waste. The heating tank 10 is provided with a safety device for stopping the gas burner 50 when the liquid level falls below a certain value, thereby preventing the gas burner 50 from burning empty.

As described above, in the present embodiment, the heating of the waste liquid in the heating tank 10, the concentration of the waste liquid in the spray chamber 20, and the drying of the waste liquid in the drying chamber 30 are performed. Since the drying in the drying chamber 30 is performed by exhausting the gas burner 50, the thermal efficiency is extremely high as compared with the above-described conventional drum dryer. In particular, in this embodiment, since the heated waste liquid is sprayed and heated by high-temperature exhaust to be vaporized, the water in the waste liquid can be efficiently vaporized.

Here, the results of an operation test of this waste liquid and water-soluble waste paint processing apparatus will be described. In a conventional drum dryer for evaporating 200 liters of water, a boiler using LPG is used as a heat source, and a boiler having an evaporation capacity of 250 kg / H is operated at 160,000 kcal.
/ H was required. On the other hand, in the device of this embodiment,
200 liters of water could be completely evaporated at 111,000 kcal / H. That is, as can be seen from the equation of 160,000−111,000 = 49000 49000 ÷ 160,000 ≒ 0.3, it has been proved that the fuel efficiency can be improved by 30% compared with the conventional drum dryer system.

Next, a second embodiment according to the present invention will be described.
The operation of the waste liquid and water-soluble waste paint processing apparatus will be described with reference to FIG. 2 and FIG. 3 showing the operation of the waste liquid and water-soluble waste paint processing apparatus. The apparatus for treating waste liquid and water-soluble waste paint of the second embodiment has substantially the same mechanical configuration as the apparatus for treating waste liquid and water-soluble waste paint of the first embodiment shown in FIG. Different in that. First, a storage tank 80 for storing waste liquid concentrated in the heating tank 10 is provided, and a pump 82 for pumping the waste liquid stored in the storage tank 80 to the drying chamber 30 is provided. A three-way valve 47 is provided to switch the waste liquid from the pump 40 for pumping the waste liquid from 10 between the spray chamber 20 side and the storage tank 80 side. Furthermore, in the second embodiment, a first liquid level sensor 91, a second liquid level sensor 92, and a third liquid level sensor 93 are provided in the heating tank 10, and a fourth liquid level sensor 94 is provided in the storage tank 80. The waste liquid and the water-soluble waste paint processing device are configured to automatically control the waste liquid treatment based on the level of the waste liquid detected by the liquid level sensor. Furthermore, in the second embodiment,
A screw conveyor 104 is provided for automatically transporting solids (sludge) accumulated in the pan 32 out of the waste liquid and water-soluble waste paint processing apparatus. The screw conveyor 104 is rotated by the driving force of the motor 108 transmitted via the belt 106, scrapes out the solid matter accumulated in the pan 32 by the screw teeth 104a, and transports the solid matter out of the processing apparatus through the cylindrical body 98. I do. Cylinder 98
A tray 112 is disposed at a position below the opening, and the solid conveyed out of the processing apparatus by the screw conveyor 104 is stored therein. In addition,
Although only one screw conveyor 104 is shown in the drawing, a plurality of screw conveyors 104 are arranged along the pan 32 in the depth direction of the drawing.

The operation of the apparatus for treating waste liquid and water-soluble waste paint according to the second embodiment will be described with reference to the flowchart of FIG. First, a waste liquid from which particles have been removed by performing a pretreatment in the same manner as in the first embodiment described above, or a water-soluble waste paint generated at the time of coating is driven by a pump (not shown) to remove the waste liquid and the water-soluble waste paint. It is sent to the heating tank 10 of the processing device (step 1). When the heating tank 10 is filled with a predetermined amount of waste liquid, the first liquid level sensor 91 detects this (determination step 2 is Yes), proceeds to step 3 and stops the pump to terminate supply of waste liquid. I do. Next, in step 4, the gas burner 50 is ignited to heat the waste liquid in the heating tank 10. Then, in step 5, the three-way valve 47 is switched to the atomizer 46a side, and in step 6, the pump 40
Is started and the waste liquid is sent to the sprayer 46a side to be sprayed in the spray chamber 20 to vaporize. Exhaust gas from the gas burner 50 is introduced into the spray chamber 20 in the same manner as in the first embodiment described above, so as to promote vaporization of waste liquid. The waste liquid is concentrated by the spray treatment, and the liquid level in the heating tank 10 gradually decreases.

When the waste liquid is concentrated and the liquid level falls below a predetermined level, the second liquid level sensor 92 detects this (Yes in decision step 7) and proceeds to the processing in step 8. In step 8, the three-way valve 47 is switched to the storage tank 80 side, and the waste liquid concentrated by this is sent to the storage tank 80 side by the pump 40. When the waste liquid is sent to the storage tank 80 and the level of the waste liquid in the heating tank 10 further decreases and falls below a predetermined level, this is detected by the third liquid level sensor 93 (judgment step 9 is Ye).
s), and proceed to step 10. In step 10, the pump 40 is stopped, the processing in this routine ends, and the flow returns to step 1 to start control of the next waste liquid processing. Although not shown, when the solids accumulate in the pan 32, the motor 108 is rotated so that the screw conveyor 104 carries out the process of unloading the solids in parallel with the above operation.

On the other hand, the concentrated waste liquid sent to the storage tank 80 is
When a predetermined amount or more is stored, it is detected by the fourth liquid level sensor 94. In response to this, the pump 82 is started, and the waste liquid is sent to the drying chamber 30 and dried on the pan 32. The drying chamber 30 has a gas burner 5 in the same manner as in the first embodiment.
Zero exhaust gas is introduced to promote drying of the waste liquid.

As described above, the waste liquid and water-soluble waste paint treatment apparatus of the second embodiment automatically treats the waste liquid. Further, in the waste liquid and water-soluble waste paint treatment apparatus of the second embodiment, the solid matter accumulated in the pan 32 can be automatically discharged using the screw conveyor 104. In this embodiment, the solid matter accumulated in the pan 32 is conveyed by the screw conveyor 104, but other conveying means, such as a belt conveyor, may be used. Further, in the second embodiment, the storage tank 80 is provided to store the concentrated waste liquid.
It is also possible to omit “0” and to directly feed the drying chamber 30 from the three-way valve 47. Further, in this embodiment, the waste liquid in the heating tank 10 is pressure-fed to the storage tank 80 side by the pump 40, but instead, the heating tank 10 and the storage tank 80 are connected by a pipe so that the waste liquid flows naturally into the storage tank 80 side. It is also possible to

Next, a third embodiment of the present invention will be described with reference to FIG. The apparatus for treating waste liquid and water-soluble waste paint according to the third embodiment is substantially the same as the apparatus for treating waste liquid and water-soluble waste paint according to the first embodiment shown in FIG. 1 and the second embodiment shown in FIG. Although an exhaust pipe 54 for introducing exhaust gas from the outside into the drying chamber 30 is further provided, the drying pipe 30 promotes drying of the waste liquid in the drying chamber 30 and vaporization of the waste liquid in the spray chamber 20. In that it is configured to The exhaust pipe 54 is adapted to introduce exhaust gas from a drying furnace of a coating machine (not shown). The waste liquid and water-soluble waste paint treatment apparatus of the third embodiment is the same as the first and second embodiments. The waste liquid treatment can be performed with less fuel than the waste liquid and water-soluble waste paint treatment apparatus. In the third embodiment, an external exhaust pipe 54 is added to the configuration of the second embodiment.
This exhaust pipe 54 can be provided in the configuration of the first embodiment.

In the above-described embodiment, an example has been described in which waste liquid generated in pretreatment for coating a metal molded article or water-soluble waste paint generated in coating is treated. Needless to say, the apparatus and method for treating a water-soluble waste paint can be used for drying various other waste liquids. Further, in the above-described embodiment, a process of removing particles (suspended matter and the like) in the waste liquid was performed before the drying process by the treatment device for the waste liquid and the water-soluble waste paint was performed. It is also possible to introduce the waste liquid directly into the waste liquid and water-soluble waste paint treatment apparatus of the present embodiment without causing the particles to solidify together with the water-soluble waste.

[0021]

As is apparent from the above description,
According to the apparatus and method for treating waste liquid and water-soluble waste paint of the present invention, the fuel cost of the drying treatment of waste liquid and water-soluble waste paint can be significantly reduced as compared with the prior art.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an apparatus for treating waste liquid and water-soluble waste paint according to a first embodiment of the present invention.

FIG. 2 is a schematic view of an apparatus for treating waste liquid and water-soluble waste paint according to a second embodiment of the present invention.

FIG. 3 is a flowchart showing control for waste liquid treatment of the waste liquid and water-soluble waste paint treatment apparatus shown in FIG. 2;

FIG. 4 is a schematic view of an apparatus for treating waste liquid and water-soluble waste paint according to a third embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 10 heating tank 20 spray chamber 30 drying chamber 40 pump 47 three-way valve 50 gas burner 52 exhaust pipe

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Chihiro Naito 1-29 Tobe-cho, Minami-ku, Nagoya City Tobe Grand Heights 311 (58) Field surveyed (Int. Cl. ⁷ , DB name) C02F 1/04

Claims (4)

(57) [Claims] 1. A heating tank for waste liquid or water-soluble waste paint, and a spray chamber for discharging, spraying and vaporizing the waste liquid or water-soluble waste paint in the heating tank, wherein the waste liquid or the water-soluble liquid is not vaporized. A spray chamber configured to return to the heating tank again, a drying chamber for extracting and drying a waste liquid or a water-soluble waste paint in the heating tank, and generating when burning fuel. by heat a heating device for heating the heating tank, before the exhaust generated during the combustion
An apparatus for treating waste liquid and water-soluble waste paint, comprising a heating device for performing vaporization in the spray chamber and drying in the drying chamber . 2. An apparatus for treating waste liquid and water-soluble waste paint according to claim 1, wherein a high-temperature gas is further introduced into said drying chamber from the outside. 3. A heating tank for a waste liquid or a water-soluble waste paint, and a spray chamber for spraying and vaporizing the waste liquid or the water-soluble waste paint in the heating tank, wherein the waste liquid or the water-soluble waste paint is not vaporized. A spray chamber configured to return to the heating tank again, a drying chamber for drying waste liquid or water-soluble waste paint, and a waste liquid or a water-soluble waste paint dried in the drying chamber. and unloading means for unloading the processing unit out of the water-soluble waste paint, a heating device for heating the heating tank by the heat generated during the combustion of fuel, before the exhaust generated during the combustion
A heating device for performing vaporization in the spray chamber and drying in the drying chamber, and a waste liquid pumping device for pumping waste liquid or water-soluble waste paint in the heating tank to the spray chamber and the drying chamber, A waste liquid pumping device for increasing the concentration of the waste liquid or the water-soluble waste paint by pumping the waste liquid or the water-soluble waste paint into the spray chamber and vaporizing the waste liquid or the water-soluble waste paint; And treatment equipment for water-soluble waste paint. 4. A step of heating a waste liquid or a water-soluble waste paint stored in a heating tank by burning fuel by a heating device, and simultaneously spraying the heated waste liquid or the water-soluble waste paint.
Vaporizing the spray with the exhaust air of the heating device , returning the non-vaporized waste liquid or water-soluble waste paint to the heating tank to increase the concentration of the waste liquid or water-soluble waste paint, and concentrating by increasing the concentration. Pumping the waste liquid or the water-soluble waste paint into a drying chamber, and introducing exhaust gas from the heating device to dry the waste liquid or the water-soluble waste paint. Processing method.