JP3504931B2 - Waste liquid dehydration equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste liquid dehydrator, and more particularly to an aqueous cutting oil waste liquid, an alkali cleaning waste liquid, a carbon polishing powder waste liquid, a coating waste liquid, a plating waste liquid, an eyeglass polishing waste liquid,
The present invention relates to a waste liquid dehydrator capable of concentrating or solidifying a waste liquid by heating the waste liquid such as a process waste liquid of a pharmaceutical company under reduced pressure. In addition, in this specification, "dehydration" generally means removing liquid components contained in the waste liquid, and the liquid removed from the waste liquid is not limited to water.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. 63-151301 and Japanese Unexamined Patent Publication No. 172584/1990 describe evaporative concentration treatment devices for photographic processing waste liquid. In this concentrating treatment device, a heat pump system is used in which the waste liquid is heated and the vapor evaporated from the waste liquid is cooled by a system of heat medium circulated by a compressor. here,
A conventional dehydrator using a heat pump system will be described with reference to FIG.

The waste water dehydrator 100 according to the prior art is
It has a concentration pot 102 for containing a waste liquid to be dehydrated, and a vapor condenser pot 104 communicating with the concentration pot 102. The dehydrator 100 further includes a compressor 106 for circulating a heat medium used for heating and cooling, an exhaust heat unit 108 for exhausting excess heat, and a concentrator 102 by allowing the heat medium to pass. Heating coil 110 for heating the waste liquid of the same, an expansion valve 112 for expanding and vaporizing the heat medium that has passed through the heating coil 110, a cooling coil 114 for cooling the discharged water, and a steam condenser 104. Condensing coil 11 for condensing vapor in the room
6 and. Further, the dehydrator 100 includes a water tank 118 for storing the discharged water, a pump 120 for pumping the water in the water tank 118, and a pump 12.
Ejector 122 for passing the water pumped by 0, thereby reducing the pressure in steam condenser 104
And.

The waste liquid stored in the concentration tank 102 is heated by the heating coil 110 arranged in the concentration tank 102. Since the pressure inside the concentrator 102 and the steam condenser 104 is reduced to a pressure lower than the atmospheric pressure by a decompression mechanism described later, the water content in the waste liquid boils at a temperature lower than 100 ° C. As a result, the waste liquid in the concentration pot 102 is concentrated. The water vapor evaporated in the concentration tank 102 moves into the vapor condensation tank 104 which is in communication with the concentration tank 102. The steam that has entered the steam condenser 104 is condensed by the condenser coil 11.
It is condensed by 6 and becomes water.

The pump 120 pressurizes the water in the water tank 118 and causes the water to pass through the ejector 122. When water passes through the ejector 122, a negative pressure is generated, and this negative pressure causes the steam in the steam condenser 104 communicating with the ejector 122 and the water condensed by the steam to flow into the flow. Pull in. The steam and water drawn into the stream flow into the water tank 118 with the water pumped by the pump 120. When the water in the water tank 118 exceeds a predetermined amount, the overflowed water flows out from the water tank 118.

Next, heating and cooling with a heat medium will be described. The heat medium that has passed through the condenser coil 116 is pressurized by the compressor 106. Compressor 106
The heat medium pressurized by
Excess heat is exhausted through 08. The temperature of the heating coil 110 is adjusted by the amount of heat exhausted from the heat exhaust unit 108. The heat medium that has passed through the heating coil 110 is concentrated in the condenser 1
It is cooled and partially liquefied by the waste liquid in 02. The partially liquefied heat medium is sucked by the compressor 106, enters the expansion valve 112, and is decompressed and expanded to lower the temperature. The cooled heat medium passes through the cooling coil 114 to cool the water in the water tank 118, and further passes through the condensing coil 116 to cool the steam in the steam condenser 104. As described above, in the heat pump system, both the heating of the waste liquid and the cooling of the steam are performed while the heating medium of one system makes one cycle.

On the other hand, Japanese Patent Application Laid-Open No. 62-201442 discloses an apparatus for evaporative concentration of photographic processing waste liquid. In this concentrating treatment apparatus, a kettle, which is disposed in the treatment chamber and contains waste liquid, is heated from outside and below the treatment chamber by a quartz tube with a built-in nichrome wire to evaporate the water content in the waste liquid.

[0008]

Problems to be Solved by the Invention JP-A-63-1513
Although the waste liquid can be concentrated in the heat pump type concentrator described in Japanese Patent Laid-Open No. 01-172584 and Japanese Patent Laid-Open No. 172584/1990, the waste liquid after the treatment is still a liquid liquid, and There is a problem that it cannot be concentrated sufficiently. Further, if the waste liquid is to be concentrated into a tar-like state or solidified by this apparatus, the concentrated waste liquid adheres to the heating coil in the concentrator, and the concentration efficiency is significantly lowered. Further, there is a problem that it is difficult to remove the waste liquid attached to the coil. Furthermore, since heating and cooling are performed by a single system heat pump, it is difficult to control both independently, and if you try to concentrate the waste liquid until it becomes tar-like or solidified, the compressor will overheat, causing trouble. In some cases.

On the other hand, in the evaporative concentration processing apparatus for photographic processing waste liquid described in Japanese Patent Laid-Open No. 62-201442, the waste liquid stored in the pot is heated from outside the pot by a heater independent of the cooling system. The above-mentioned problems are solved because of the structure. However, with this device,
Since the heater is provided independently, there is a problem that energy efficiency is low. Also, placed in the processing chamber,
Since the heating means is provided outside the processing chamber for the pot containing the waste liquid, there is a problem that heat escapes to the periphery of the apparatus and energy efficiency further deteriorates.

It is an object of the present invention to provide a waste liquid dehydrator with high energy efficiency, which is capable of concentrating waste liquid until it becomes tar-like or solidified.

[0011]

In order to solve the above-mentioned problems, the present invention provides a dehydrator for condensing or solidifying the waste liquid by heating the waste liquid under reduced pressure, and a decompression chamber, A processing tank provided in the decompression chamber for accommodating the waste liquid to be dehydrated, a heating means provided outside the processing tank, and a liquid component in the waste liquid evaporated in the decompression chamber, which communicates with the decompression chamber. A condensing chamber for receiving the steam of
Decompression means for decompressing the decompression chamber and the condensing chamber, a condensing coil arranged in the condensing chamber for condensing the vapor in the condensing chamber, and a refrigerant flowing in the condensing coil for cooling the condensing coil. , A compressor, an expansion valve, and a cooling unit including an exhaust heat unit, and the heating by the heating unit and the cooling by the cooling unit can be independently adjusted.

According to this structure, the waste liquid to be treated is heated in the treatment tank provided in the decompression chamber decompressed by the decompression means. The vapor of the liquid component in the waste liquid evaporated in the decompression chamber enters the condensing chamber, is condensed by the condensing coil, and returns to the liquid. The condenser coil is cooled by a cooling unit including a compressor, an expansion valve, an exhaust heat unit, and the like. Further, since the heating by the heating means and the cooling by the cooling means are configured in different systems, the waste liquid can be sufficiently dehydrated without burdening the heating means and the cooling means. Further, since the waste liquid is heated from the outside of the processing tank by the heating means, the heating means is contaminated by the waste liquid and heated as in the case of directly inserting the heating coil into the waste liquid to heat the waste liquid. Problems such as deterioration of efficiency and adhesion of waste liquid to the heating means can be eliminated.

Further, the waste liquid dehydrator of the present invention heats the waste liquid under reduced pressure to evaporate the liquid component in the waste liquid and condense and collect the evaporated liquid component to concentrate or solidify the waste liquid. In the dehydrator for performing the above, a decompression chamber, decompression means for decompressing the decompression chamber, a treatment tank provided in the decompression chamber for accommodating waste liquid to be dehydrated, and a treatment tank provided outside the treatment tank. And a heating means. Further, it is preferable that the heating means is provided with a water jacket provided on the outer circumference of the treatment tank for flowing hot water.

Further, it is preferable that the processing tank and the heating means are disposed in the decompression chamber in an adiabatic manner with respect to the decompression chamber. According to this configuration, the processing tank to which the heating means is attached is in adiabatic contact with the decompression chamber, that is, the heating means and the processing tank are in contact with each other so that heat is less likely to be conducted to the decompression chamber. And the heat of the processing tank is mainly transferred through the depressurized space between the depressurization chamber and the heating means,
High heat insulation can be obtained. This can increase the energy efficiency of the heat insulating device.

Preferably, a demister is attached to the opening above the processing tank. According to this configuration, when the waste liquid boils in the processing tank, it is possible to prevent the waste liquid from scattering outside the processing tank.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic diagram of a waste liquid dehydrator 1 according to an embodiment of the present invention. The waste liquid dehydrator 1 according to the present embodiment includes a heating dehydrator unit 2 and a condensing unit 4.

The heating / dehydrating unit 2 includes a heater 6 for warming the water for heating the waste liquid, a hot water tank 8 for storing the water for heating, and a hot water pump 10 for circulating the hot water for heating. Have. In addition, heating dehydration unit 2
Is a treatment tank 12 having an upper opening for accommodating the waste liquid to be dehydrated, and a water jacket 13 which is attached to the outside of the treatment tank 12 and is a heating means for heating the waste liquid in the treatment tank 12. A demister 14 attached to the opening of the processing tank 12 for preventing the waste liquid in the processing tank from scattering, and a decompression chamber 16 for accommodating the processing tank 12 and decompressing the room. The demister 14 is, for example,
A stainless steel basket matching the shape of the opening of the processing tank 12 is attached to the opening, and the thickness of the basket is 20 to 40 mm.
It can be constructed by filling a degree of nylon mesh. Nylon mesh should be of suitable mesh size so that steam can pass easily and viscous splashes can be blocked.

The processing tank 12 is in contact with the decompression chamber 16 only by the legs 12a having a small cross-sectional area.
The water jacket 13 is configured so as not to come into direct contact with the decompression chamber 16. That is, the processing tank 12 and the water jacket 13 are arranged in the decompression chamber 16 in an adiabatic manner. Preferably, the processing tank 12 is SUS-3.
It is made of a material having high corrosion resistance such as 04. Hot water pump 10
Is connected to the water jacket 13 so that the hot water in the hot water tank 8 heated by the heater 6 circulates in the water jacket 13.
Instead of the heater 6, hot water may be heated with steam, high-temperature water, or the like. The decompression chamber 16 may have a round shape or a rectangular shape, and packing is attached to maintain the degree of vacuum.

Further, the heating and dehydrating unit 2 includes the processing tank 12
And a liquid level sensor 20 for detecting the height of the liquid level of the waste liquid in the processing tank.
And a vacuum pressure switch 2 for monitoring the concentration of waste liquid
2, a pipe 24 for guiding the vapor evaporated from the waste liquid to the condensing unit 4, and a concentrated waste liquid discharge port 26 for discharging the concentrated waste liquid. Depending on the application, a pressure device (not shown) for pressurizing the waste liquid may be attached to the decompression chamber 16 in order to push out the concentrated and high-viscosity waste liquid from the concentrated waste liquid discharge port 26. Alternatively, for discharging the concentrated waste liquid, instead of using the concentrated waste liquid discharge port 26,
It can also be performed using a bag (not shown). That is, a paper bag that allows water to pass through is treated in the treatment tank 1
The waste liquid to be treated is placed in the container No. 2 and the waste liquid to be treated is put therein to be dehydrated. After the treatment, the concentrated or solidified waste liquid is taken out together with the bag and discharged. It is preferable that the bag-like material be easily attached to the treatment tank 12 so that the heat of the treatment tank 12 is well transferred to the waste liquid.
Also, a fine mesh bag made of resin can be used as a bag-like material.

The waste liquid supply device 18 controls the supply and stop of the waste liquid by an electromagnetic valve or the like. The liquid level sensor 20 is inserted into the processing tank 12 from the outside of the decompression chamber 16,
It is configured to detect the height of the liquid surface of the waste liquid inside. The liquid level sensor 20 can be configured by, for example, a float type sensor or an electrode rod. Further, the vacuum pressure switch 22 is configured to detect the pressure in the decompression chamber 16 and operate based on the detected pressure.

On the other hand, the condensing unit 4 corresponds to the conventional heat pump type concentrating device from which the portion for heating the waste liquid is removed. That is, the condensing unit 4 includes a condensing chamber 28 to which steam is guided by the pipe 24, a condensing coil 30 for cooling and condensing the vapor in the condensing chamber 28, and a vapor condensed by the condensing coil 30 in the condensing chamber 28. And a discharge pipe 31 for discharging. The decompression chamber 16 and the condensation chamber 28 communicate with each other by a pipe 24 and are hermetically sealed as a whole. Preferably, the condensing chamber 28 and the condensing coil 30 are made of a material having high corrosion resistance such as SUS-304.

The condensing unit 4 includes a compressor 32 for circulating the refrigerant in the cooling system, an exhaust heat unit 34 for discharging the heat of the refrigerant, an expansion valve 36 for decompressing and expanding the refrigerant. Have. The compressor 32, the exhaust heat unit 34, and the expansion valve 36 constitute a cooling means. Further, the condensing unit 4 has a water flow tank 38 for containing water condensed in the condensing chamber 28.
The cooling coil 40 for cooling the water in the running water tank 38, the circulation pump 42 for circulating the water in the running water tank 38, and the water circulated by the circulation pump to pass through the condensing chamber 28. And an ejector 44 which is a decompression unit for decompressing the inside of the decompression chamber 16.
Further, the condenser coil 30, the compressor 32, the exhaust heat unit 34, the expansion valve 36, and the cooling coil 40 are connected to the conduit 3
7a to 37e, respectively. The running water tank 38, the circulation pump 42, and the ejector 44 are connected by pipes 45a to 45c.

The exhaust heat unit 34 is composed of a heat exchanger having exhaust heat fins, an exhaust heat fan, and the like. Further, the water in the running water tank 38 is sucked by the circulation pump 42 through the pipe 45a, and is ejected through the pipe 45b.
Enter 4. The water that has passed through the ejector 44 is a pipe 45c.
It is configured to pass back into the water in the running water tank 38. Further, the discharge pipe 31 is connected to the ejector 44, so that the cooled water in the running water tank 38 can flow at high speed,
When passing through the ejector 44 at a high pressure, the steam in the condensing chamber 28 and the water in which the steam is condensed are sucked from the discharge pipe 31. Preferably, the running water tank 38 and the cooling coil 40 are made of a material having high corrosion resistance such as SUS-304.

The high pressure side of the compressor 32 has a conduit 37a.
Is connected to the inlet side of the heat exchanger of the exhaust heat unit 34. The outlet of the heat exchanger of the exhaust heat unit 34 is connected to the high pressure side of the expansion valve 36 by a pipe line 37b.
The low-pressure side of the expansion valve 36 is connected to the cooling coil 40 by a conduit 37c, and the other end of the cooling coil 40 is connected to the conduit 37d.
Is connected to the inlet side of the condenser coil 30. The outlet side of the condenser coil 30 is connected to the inlet side of the compressor 32 by a conduit 37e. Preferably, the conduit 37 connecting the respective parts is made of copper.

Further, as an auxiliary device, the condensing unit 4
Is for adjusting the cooling capacity of the condensing unit 4 by bypassing the temperature sensing part 46 for adjusting the expansion valve 36 based on the temperature of the refrigerant passing through the condensing coil 30 and the refrigerant passing through the compressor 32. Capacity adjustment valve 48
And. The temperature sensing unit 46 is attached to the outlet side of the condensing coil 30, the output of the temperature sensing unit 46 is connected to the expansion valve 36, and is configured to adjust the expansion valve 36.
Further, the capacity adjusting valve 48 is attached so as to connect the inlet side and the outlet side of the compressor 32.

Next, the operation of the waste liquid dehydrator 1 according to the embodiment of the present invention will be described. First, the waste liquid supply device 18 introduces a waste liquid to be treated, for example, a water-based cutting oil waste liquid, into the treatment tank 12. When a predetermined amount of waste liquid is introduced into the processing tank 12, the liquid level sensor 20 detects it and stops the introduction of the waste liquid by the waste liquid supply device 18. Then
By operating the circulation pump 42, the ejector 4
The air in the decompression chamber 16 and the condensation chamber 28 is sucked by 4 to reduce the pressure in each chamber. Further, the heater 6 is operated to heat the water in the hot water tank 8. When the inside of the decompression chamber 16 is depressurized to a predetermined pressure, the hot water pump 10 is operated, and hot water is circulated in the water jacket 13.
Heat waste liquid. In this embodiment, the decompression chamber 16 has 50
When the pressure is reduced to about 0 torr, heating of the waste liquid is started. In addition, about 20 in the water jacket 13
Hot water with a stable temperature of -60 ° C is circulated.
By circulating hot water in the water jacket 13, the water in the waste liquid in the processing tank 12 evaporates.

Since the inside of the decompression chamber 16 is decompressed by the decompression action of the ejector 44, the water content in the waste liquid boils and evaporates at 20 to 60 ° C. Preferably, the waste liquid is boiled while preventing detonation by boiling at a pressure of 20 to 40 torr and a heating temperature of 20 to 65 ° C. Further, the demister 14 attached to the opening of the processing tank prevents the waste liquid from scattering outside the processing tank when boiling.
Since the processing tank 12 and the water jacket 13 are in contact with the outer decompression chamber 16 only by the legs 12a of the processing tank, the heat of the water jacket 13 is reduced by the decompression chamber 16
Hardly conducts to. In addition, the water jacket 13
And the decompressed space between the decompression chamber 16 and the decompression chamber 16 acts as a heat insulating layer, and minimizes heat transfer from the water jacket 13 to the decompression chamber 16. Further, as the dehydration of the waste liquid progresses and the evaporation amount of water decreases, the vapor pressure in the decompression chamber decreases, so that the degree of vacuum increases and the dehydration efficiency improves.

The vapor evaporated in the decompression chamber 16 is pipe 2
4 into the condensing chamber 28. The steam that has entered the condensing chamber 28 is cooled by the condensing coil 30 and condensed into water. The water condensed in the condensing chamber 28 enters the ejector 44 through the discharge pipe 31, and flows into the running water tank 38 together with the water circulated by the circulation pump 42. The water overflowing from the running water tank 38 is drained to sewage. Also,
When the water condensed in the condensing chamber 28 enters the ejector 44, vapor in the condensing chamber 28 and gas such as air are also ejected by the ejector 44.
Is sucked from the discharge pipe 31 by the
8 and the inside of the decompression chamber 16 are decompressed. In the present embodiment, this pressure reducing action reduces the pressure in the pressure reducing chamber 16 and the condensing chamber 28 to 10 to 40 torr. Further, in the present embodiment, the COD value of the water overflowing from the running water tank 38 and discharged to the sewage is reduced to about 150 with respect to the waste liquid having the COD value of 100,000 or more.

The coolant for cooling the condenser coil 30 is
It is pressurized by the compressor 32. Compressor 3
The refrigerant pressurized by 2 is deprived of heat by the exhaust heat unit 34 and enters the expansion valve 36. The refrigerant that has entered the expansion valve 36 is decompressed and expanded by the expansion valve, and the temperature drops. The coolant whose temperature has dropped cools the water in the running water tank 38 through the cooling coil 40, and further, the condensation coil 30
To cool the vapor in the condensing chamber 28. The refrigerant passing through the condenser coil 30 returns to the compressor 32 and is pressurized again.

The temperature sensing section 46 detects the temperature of the refrigerant passing through the condenser coil 30 and automatically adjusts the expansion valve 36.
That is, the temperature of the condenser coil 30 and the cooling coil 40 is too low, and the surroundings of the coil are frozen, or the temperature of the coil is too high to prevent sufficient cooling.
The valve opening degree of the expansion valve 36 is adjusted. Also, the capacity adjustment valve 48
Adjusts the cooling capacity of the entire cooling system by returning a part of the refrigerant pressurized by the compressor 32 to the inlet side of the compressor 32.

When the waste liquid in the processing tank 12 is sufficiently concentrated, the vacuum pressure switch 22 detects it and the dehydrator 1
To stop. That is, when the water content of the waste liquid in the processing tank 12 decreases, the evaporation amount of the water decreases, which causes the pressure in the decompression chamber 16 to rapidly decrease. Due to this decrease in pressure, the vacuum pressure switch 22 automatically operates to stop the dehydrator 1. When the concentration of the waste liquid is completed, the concentrated waste liquid discharge port 26 is opened, the concentrated waste liquid is discharged, and the processing ends.

According to the present embodiment, since the waste liquid is heated from the outside of the processing tank 12, the waste liquid is tar-like until the waste liquid becomes tar-like.
Alternatively, even if dehydration is performed until solidification, they do not adhere to the heating coil. Further, since the waste liquid is heated by the water jacket 13 which is a separate system from the cooling coil 30, the compressor 32 for cooling the steam is not burdened,
The waste liquid can be sufficiently dehydrated, and various protection circuits for protecting the compressor 32 become unnecessary. Thereby, while avoiding the failure of the compressor 32, it is possible to perform dehydration in a stable operation until the waste liquid becomes tar-like or solidifies. Further, the water jacket 13 for heating the waste liquid is provided in the decompression chamber 1.
Water jacket 1 because it is not in direct contact with 6
The amount of heat that escapes from the vacuum chamber 16 to the outside of the decompression chamber 16 is small, and the energy efficiency is high. Further, since the depressurized space between the processing tank 12 and the depressurization chamber 16 effectively acts as a heat insulating layer,
There is no need to provide special heat insulating material. Also, since the condensed water that exits the condensation chamber is discharged into the water in the water flow tank,
No offensive odor or vapor is emitted to the outside air.

While the preferred embodiments of the present invention have been described above, various modifications may be made to the disclosed embodiments within the scope of the technical matters described in the claims without departing from the scope or spirit of the present invention. Can be changed. In particular, in the embodiment of the invention, the dehydration apparatus for the water-based waste liquid, that is, the waste liquid containing water as the main component has been described. However, the present invention contains the liquid for drying raw garbage and other liquids other than water as the main component. It can also be applied to the treatment of waste liquid. Further, in the dehydrator of the present invention, it is possible to evaporate, separate, condense or the like a liquid having a low boiling point other than water. Further, not only waste but also liquid foodstuffs can be dehydrated.

[0034]

According to the present invention, the waste liquid can be concentrated with high energy efficiency until it becomes tar-like or solidifies.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a waste liquid dehydrator according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a conventional waste pump dehydrator using a heat pump system.

[Explanation of symbols]

1 Waste liquid dehydrator 2 heating dehydration unit 4 Condensing unit 6 heater 8 hot water tank 10 Hot water pump 12 treatment tanks 13 water jacket 14 Demister 16 decompression room 28 Condensation chamber 30 condensing coil 32 compressor 34 Exhaust heat unit 36 Expansion valve 38 running water tank 40 cooling coil 42 Circulation pump 44 ejector

Continuation of front page (56) Reference JP-A 63-151301 (JP, A) JP-A 10-272454 (JP, A) JP-A 2-253803 (JP, A) JP-A 62-102883 (JP , A) Actual Kaihei 2-57101 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) C02F 1/04-1/18 B01D 3/00-3/32

Claims (3)

(57) [Claims] 1. A dehydrator for concentrating or solidifying a waste liquid by heating the waste liquid under reduced pressure, and a decompression chamber and a waste liquid to be dehydrated provided in the decompression chamber. Treatment tank, heating means provided outside the treatment tank, a condensing chamber that communicates with the decompression chamber and receives vapor of a liquid component in the waste liquid evaporated in the decompression chamber, the decompression chamber and the decompression chamber. A decompression means for decompressing the condensing chamber, a condensing coil arranged in the condensing chamber for condensing the vapor in the condensing chamber, and a compressor for flowing a refrigerant through the condensing coil to cool the condensing coil. A cooling means including an expansion valve and an exhaust heat unit, heating by the heating means and cooling by the cooling means can be adjusted independently, and the processing tank and the heating means Room During the dehydration apparatus of the waste, characterized by being adiabatically arranged relative to the vacuum chamber. 2. The apparatus for dehydrating waste liquid according to claim 1 , wherein the heating means includes a water jacket provided on the outer periphery of the treatment tank for flowing hot water. 3. The processing tank has an opening at the top, and a demister is attached to the opening.
The dehydrator for waste liquid according to claim 1 or 2 .