JP3100989B2 - Aqueous solution evaporator - 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 for evaporating and concentrating an aqueous solution such as a photographic processing waste liquid.

[0002]

2. Description of the Related Art A conventionally known apparatus for evaporating and concentrating an aqueous solution includes, for example, a processing waste liquid (processing waste liquid such as development, fixing, and washing) generated in a photographic processing step of a silver halide photographic light-sensitive material. The wastes are disposed after subjecting to known pollution treatment methods such as evaporation, evaporation, electrolytic oxidation, ion exchange, reverse osmosis, and chemical treatment. However, a reliable treatment has not yet been achieved. Not in. Here, there is also an apparatus for evaporating and condensing photographic processing waste liquid previously proposed by the present applicant. This evaporating and concentrating apparatus has an evaporating and concentrating chamber (column) in which a heating means communicating with the upper part is provided, and a cooling means is provided outside the evaporating and concentrating chamber (column). The cooling condensing chamber (column) in which is disposed is a concentric double airtight chamber configuration, the heating means is a condenser of a heat pump, the cooling means is an evaporator, and the condenser (heating unit heat exchanger) And the coil that constitutes the evaporator (cooling unit heat exchanger)
Both have a spiral wound structure having the same predetermined interval (pitch).

[0003]

However, in such a spiral wound structure in which both coils have a fixed interval,
In the heating part which becomes the condenser of the heat pump, the heat transfer efficiency of the liquid surface portion where the processing waste liquid boils is poor, and in the cooling part which receives the waste liquid vapor (water vapor) which becomes the evaporator, on the contrary, the same as above not utilized Do chamber space well in turns regularly spaced, the residence time in the air in the droplet contains a defect, such as the absorption of noncondensable gases is not very good short. The present invention has been made in view of the above circumstances, and has as its object to provide an apparatus for evaporating and concentrating an aqueous solution in which the coil pitch of a heating unit and a cooling unit is improved to promote evaporation and improve absorption of non-condensable gas.

[0004]

According to the present invention, there is provided a concentrator having a heating chamber and a cooling chamber which communicate with each other at an upper part, a compressor,
It has a heat pump that connects a condenser, a decompression device, and an evaporator, a liquid supply device that supplies an aqueous solution to the heating chamber, and a deaeration device that decompresses the inside of the concentrator. The condenser of the heat pump is placed in the heating chamber. In addition, in the evaporating and concentrating apparatus for an aqueous solution in which an evaporator is arranged in a cooling chamber, the condenser and the evaporator each have a coil shape having a refrigerant inlet at an upper part and a refrigerant outlet at a lower part. It is made coarser than the coil pitch of the condenser.

[0005] The refrigerant pipe on the outlet side of the condenser is raised upward from the refrigerant outlet of the condenser, and a small tube smaller than the diameter of the condenser is inserted into the rising portion. .

[0006]

With the above construction, the treatment waste liquid (aqueous solution) from the waste liquid tank is guided to the heating portion at the center position of the condensing kettle, which is preliminarily depressurized by the ejector, and is constantly stored in a constant amount.
In this heating section, the waste liquid boils at a low temperature due to the reduced pressure in the condenser using the heat pump as a heating source. In this case, the spiral coil pitch constituting the condenser winds the heating tube densely at least near the liquid surface. As a result, the heat transfer area is concentrated, so that heat transfer is good and evaporation is promoted. The evaporated water vapor flows into a cooling chamber located at an outer peripheral position and is condensed in the evaporator. This condensed water flows out to the ejector water tank, and is discharged to a separate condensed water tank by overflow.
Also, if the liquid level drops due to the amount of water vapor generated by boiling, the level sensor that becomes the submerged electrode in the heating unit detects it, opens the waste liquid suction solenoid valve by the reduced water level, replenishes the waste liquid from the waste liquid tank, and sequentially concentrates. Go. When the density reaches a predetermined level, the density is appropriately extracted from the bottom of the heating unit. On the other hand, the refrigerant flowing out of the condenser (heating chamber side) constituting the heat pump is depressurized by the decompression device and flows to the evaporator of the cooling chamber via the first evaporator facing the water tank for ejector (cooling tank).
Thereafter, the evaporated refrigerant is returned to the compressor, compressed, and a refrigeration cycle in which the refrigerant flows from the first condenser to the condenser in the heating chamber.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings of the embodiments.

FIG. 1 is a schematic view of an evaporating and concentrating apparatus.
Is a concentrating kettle having a concentric double structure with a heating chamber 2 and a cooling chamber 3 which communicate with each other at the upper part. A condenser 5 of a heat pump 4 is accommodated in the heating chamber 2 for storing waste liquid, and cooling is performed. Room 3
An evaporator 6 is accommodated therein. In this case, the spiral coil pitch of the condenser 5 serving as a heating tube has a structure in which at least the vicinity of the liquid level of the reservoir is closely wound, and a pipe 5 ′ serving as a lower end outlet of the condenser 5 is set up therein. The helical coil pitch of the condenser tube of the evaporator 6 on the outer side is made to be a helical winding coarser than the coil pitch of the condenser 5, and the space of the cooling chamber 3 is effectively used to make the steam To increase the fall time. Numeral 8 denotes a liquid supply device connected to the waste liquid tank 9, the leading end of which is guided to the upper part of the heating chamber 2, and a concentrated liquid container 11 is installed outside a discharge port 10 provided at one end of the bottom of the heating chamber 2. Reference numeral 12 denotes an ejector pipe connected to the condensed liquid recovery port 3 a at the bottom of the cooling chamber 3. The ejector pipe 12 is connected to an ejector 14 of a deaerator 13. And a circulation circuit that connects an end of the ejector 14 to the other end of the ejector 14 with an ejector pump 16 interposed in a pipe extending from the water tank 15. In addition, water tank 1
5 accommodates a first evaporator 18 serving as a cooling means at the tip of a pressure reducing device 17 connected to a pipe leading from the condenser 5;
The tip of the first evaporator 18 is connected to the upper end of the evaporator 6 of the cooling chamber 3, and a pipe led from the lower end of the evaporator 6 is connected to the compressor 19.
The compressor 19 is connected to the upper end of the condenser 5 via a first condenser 21 for cooling the compressor 19 with a fan 20 to constitute the heat pump 4.

Next, this operation will be described. First, as a pre-process of the operation of the compressor 19 of the heat pump, the ejector pump 16 is operated to operate the ejector 14 to bring the inside of the concentration chamber 1 to a predetermined reduced pressure state in advance. In addition, if the suction electromagnetic valve 22 of the liquid supply device 8 is opened under reduced pressure in the concentration chamber 1, the waste liquid from the waste liquid tank 9 can flow out at a negative pressure and flow into the heating chamber 2. The control of the waste liquid amount in the heating chamber 2 is performed by detecting the liquid level in the heating chamber 2 with the level sensor 23.

Here, the compressor 1 of the heat pump 4
9 drives the refrigerant through the first condenser 21 to flow into the condenser 5 of the heating chamber 2 of the concentrator 1, and the heat exchange in the condenser 5 heats the waste liquid flowing into the heating chamber 2. And boil low. In this case, since the coil pitch of the heating tubes constituting the condenser 5 is at least dense near the liquid surface (the entire heating tube is tightly wound in the drawing), the heat transfer area of the heating tubes is concentrated near the liquid surface. And the heat transfer is good and the waste liquid boils. Here, the evaporated water vapor of the waste liquid flows into the cooling chamber 3 at the outer peripheral position, is cooled and condensed by the condenser tube of the evaporator 6, and is collected as water droplets. At this time, since the coil pitch of the evaporator 6 is a spiral winding that is coarse, the space of the cooling chamber 3 is inevitably used effectively, the falling time of water vapor is long, the non-condensable gas is absorbed, and the evaporator 6 Condensed water is dropped from the upper side. The condensed water of the waste liquid collected at the bottom of the cooling chamber 3 is guided to the ejector water tank 15, and the condensed water in the water tank 15 is discharged to a separate condensed water tank 24 by overflow. Further, in this way, in the heating chamber 2, the waste liquid is sequentially concentrated, and only the reduced amount of the waste liquid due to the evaporation is detected by the level sensor 23 to operate the liquid supply device 8 to sequentially pump the waste liquid. However, the suction electromagnetic valve 22 of the liquid supply device 8 is opened intermittently, and prevents foaming of the waste liquid in the heating chamber 2.

On the other hand, since the narrow pipe 7 hanging down from above faces the outlet path of the liquid refrigerant flowing out from the lower end of the condenser 5 serving as a refrigeration cycle, a flow velocity for flowing only the liquid refrigerant is secured. The liquid refrigerant leaving the condenser 5 is supplied to the decompression device 1
The pressure is reduced in step 7, and the refrigerant flows into the first evaporator 18 of the water tank 15 serving as a cooling means. The evaporating refrigerant is guided to the condenser tube of the evaporator 6, and the water vapor of the waste liquid evaporated in the condenser 5 of the heating chamber 2 is captured. The condensed water dropped by this evaporator 6 is condensed liquid recovery port 3
The water is led to the water tank 15 from a, and the water overflowing in the water tank 15 is collected in the condensed water tank 24.

The concentrated waste liquid accumulated at the bottom of the heating chamber 2 is judged by a separate detecting means (detection of the refrigerant temperature), and after a predetermined operation is stopped, the outlet 10 is opened and the concentrated waste liquid is allowed to flow into the concentrated liquid container 11. I just need. At this time, if necessary, the scraping blade (not shown) provided at the bottom of the heating chamber 2 is rotated to forcibly discharge.

The above-described apparatus for evaporating and concentrating an aqueous solution is housed in a box except for the waste liquid tank 9, the concentrated liquid container 11 and the condensed liquid tank 24. The fan 20 sucks external air into the box, and After cooling the parts, the first condenser 2
1 to the outside, the first condenser 21
Can be made compact.

[0014]

As described above, the present invention is directed to a concentrating pot in which a heating chamber and a cooling chamber are doubled inside and outside, in which the coil pitch of a heating tube serving as a condenser in the heating chamber is tightly wound, and the cooling chamber is evaporated. Because the coil pitch of the condenser tube that becomes the vessel becomes a coarse winding,
The heat transfer area near the liquid level of the waste liquid increases, and the boiling can be activated,
In addition, in the cooling chamber, the evaporating water vapor can fall for a longer time, so that the non-condensing gas can be removed by absorbing the non-condensable gas and combining with the low-temperature boiling. Further, when the rising path serving as the outlet of the condenser has a large diameter of the heating tube, a double tube structure in which a thin tube is disposed inside ensures a flow rate of the refrigerant and allows only the liquid refrigerant to flow. Done
This has the effect that the flow of the refrigerant can be optimized and the evaporative concentration ability can be increased.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Concentration tank 2 Heating chamber 3 Cooling chamber 4 Heat pump 5 Condenser 6 Evaporator 7 Thin tube 8 Liquid supply device 13 Deaerator

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Soichiro Shibata 1-3-1 Uchisaiwaicho, Chiyoda-ku, Tokyo Tokyo Electric Power Company (72) Inventor Noriyuki Shimamura 1-1-1 Uchisaiwaicho, Chiyoda-ku, Tokyo Tokyo Inside Electric Power Company (72) Inventor Masayuki Kurematsu 1 Sakuracho, Hino-shi, Tokyo Konica Corporation Hino Office (72) Inventor Satoshi Yuzawa 1 Sakuracho, Hino-shi, Tokyo Konica Corporation Hino Office (72 Inventor Toshiaki Kawada 2-16-16 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Inventor Yukio Yoshioka 2-16-16 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (56) References JP-A-3-293079 (JP, A) JP-A-3-293080 (JP, A) JP-A-60-206401 (JP, A) JP-A-50-78569 (JP, A) P, A) JitsuHiraku Akira 54-93038 (JP, U) (58 ) investigated the field (Int.Cl. ^7, DB name) B01D 1/02 C02F 1/04

Claims (2)

(57) [Claims] 1. A concentrator having a heating chamber and a cooling chamber communicating with each other at an upper portion, a heat pump connecting a compressor, a condenser, a decompression device, and an evaporator, and a liquid supply device for supplying an aqueous solution to the heating chamber. And a deaerator for depressurizing the inside of the concentrator, wherein the condenser of the heat pump is disposed in the heating chamber and the evaporator is disposed in the cooling chamber. An apparatus for evaporating and concentrating an aqueous solution, wherein the evaporator has a coil shape having a refrigerant inlet at an upper part and a refrigerant outlet at a lower part, and a coil pitch of an evaporator is made coarser than a coil pitch of a condenser. 2. The refrigerant pipe on the outlet side of the condenser is raised upward from the refrigerant outlet of the condenser, and a small tube smaller than the diameter of the condenser is inserted into the rising portion. An evaporating and concentrating apparatus for an aqueous solution of 1.