KR810000735B1 - Apparatus for concentrating aqueous solution - Google Patents

Abstract

Aq. soln. of high b.p. organic atifreeze is conc. by exposing the aq. soln. to a warm air stream and evapg. water from the soln. into the air to produce a highly humid airvapour stream and a liq. conc., in the antifreeze droplets(20) which is passed through a first screen(44a) to trap the droplets and raise the relative humidity of the air-vapour stream leaving the screen. This stream is cooled to condense a second mist of antifreeze droplets which is passed through a second screen(44b) to trap the droplets and raise the relative humidity of the air-vapour stream leaving the screen.

Description

Device for concentrating aqueous solution

The longitudinal cross-sectional view of the reconcentration apparatus of this invention.

The present invention relates to an apparatus for reconcentrating an aqueous solution containing an organic antifreeze having a boiling point higher than that of a normal water.

In the technical background such as the present application, an air cooler that is capable of exhibiting 100% capacity continuously for 24 hours by preventing freezing of a cooling coil of an air cooler is an extremely recent technology, and its history is short since it is not considered in the past. . The condenser was also used with a very simple clean tower.

Accordingly, the present inventors developed the technology focusing on this apparatus from about 50 years ago, and developed an antifreeze, an air cooler, a concentrator, etc. as an apparatus. Among them, the concentrating device was developed and completed, and its performance is excellent and functionally used.

The features of the present application are listed in comparison with the prior art as follows.

(A) Enhancement of concentration by lowering the relative humidity of air by active air heating,

(B) Promote the gas-liquid contact by the saddle layers to increase the concentration capacity,

(C) Prevents heat loss by direct heating to spray buoys and prevents overheating of antifreeze.

(D) prevent the droplet separation and the loss of the antifreeze by the U stage mechanism of the air stream;

(E) preventing the loss of antifreeze by preventing the entrainment of the spray caused by the parallel flow of spray and air;

(F) pray for the active recovery of antifreeze using the difference in condensation temperature;

(G) Reduce equipment costs by enhancing performance.

Due to the above characteristics, there is a functional effect of recovering expensive antifreeze (loss rate, evaporated water) and reducing 0.8-1% per pound to about 0.24%. In addition, the antifreeze, that is, the water-soluble organic antifreeze, is a physically and chemically stable at high and low temperatures in the use temperature range as its required properties, and has high affinity for water. It is not toxic or corrosive, has low ice crystals and low viscosity and high boiling point.

To achieve these characteristics, special inhibitors are added, but the common liquids used in antifreeze are ethylene glycol, propylene glycol, and triethylene glycol, which are concentrated at low temperatures in which no change in denaturation or decomposition occurs during use. The point is that the device is designed so as to design the flow of moisture using the partial pressure of water vapor in the air.

Compared with the conventional dry coil air cooler as mentioned above, the wet coil type of the present invention enables the automation of refrigeration, lowers the condensation temperature, lowers the equipment cost, and lowers the operating cost, thereby improving the indoor sanitary environment. It works. As described in 1974 Patent Application No. 3321 for the heat exchanger, the recycled aqueous solution gradually becomes thinner when the antifreeze used repeatedly to prevent freezing of the air cooling coil maintained at the freezing point. When antifreeze is injected into an air cooling coil maintained at the freezing point in a heat exchanger or the like, humidity in the air can be prevented from freezing in the coil, but this moisture is absorbed into the antifreeze as a diluent and makes the antifreeze lean. Furthermore, the loss of antifreeze is not economically beneficial.

In the heat exchanger, it is necessary to keep the concentration of the antifreeze relatively high in order to maintain the effect of the antifreeze preventing the freezing of the air cooling coil. For this reason, to keep the antifreeze at the required concentration, it is necessary to regularly or continuously remove some of the moisture absorbed by the antifreeze during use. Accordingly, the present invention provides a novel multilayer reflux concentrator.

Thus, each continuous layer herein further reduces the loss of organic passivators and more importantly allows the droplets of the solution attached to the recovery filter in the upper layer to fall and move to the lower filter. The purpose of the present invention is to increase the function of recovering the antifreeze in the lower layer by cleaning the filter and diminishing the concentration of the solution on the filter. As high humidity air passes through the device, it gradually increases relative humidity and lowers the dew point in each layer of continuous reflux to further increase the device's function and reduce the loss of antifreeze.

One of the main objectives of the present invention is to provide a device in which this aqueous solution is concentrated with little loss of organic antifreeze.

It is another object of the present invention to provide an apparatus for concentrating an organic antifreeze solution by a relatively simple structure and an economical apparatus.

Hereinafter, the configuration of an embodiment of the present invention according to the accompanying drawings.

The main body 10 is comprised by the two upright chambers 12 and 14 and the inclined connection part 16 which mutually connects in the lower end part of these upright chambers 12 and 14 ,. In the lower part of the upright chamber 12, the aqueous solution 20 tank 18 of the organic antifreeze with a relatively high boiling point is formed. The upright chamber 12 is open at its upper end to form an air inlet 11. The aqueous solution 20 tank 18 is provided with a floating valve 20 for adjusting the amount of the aqueous solution 20.

In addition, an inflow pipe 24 for supplying an antifreeze to the aqueous solution 20 tank 18 is provided at the lower end of the upright chamber 12, and the aqueous solution 20 is discharged from the aqueous solution 20 tank 18. The pump 26 is provided near the lower end of the upright chamber 12.

The pump 26 is provided with the discharge pipe 26 which has the suction pipe 28 and the branch pipe 30 ', and the branch pipe 30' is provided in the discharge pipe 30. As shown in FIG. The branch pipe 30 'supplies the concentrated solution to the heat exchanger, and the discharge pipe 30 enters the upright chamber 12 at the upper air inlet 11 opened along the upright chamber 12, and the downward spray nozzle 32 It is attached. Under the air inlet 11 of the upright chamber 12, an air inlet filter 34 made of a suitable fibrous material such as vitreous fibers is provided. The spray nozzle 32 penetrates through the filter 34 and protrudes inside the upright chamber 12, and a heating coil layer 36 is provided below the filter 34 that is heated by a suitable medium such as water vapor. In addition, the saddle layer 38 is provided under the heating coil layer 36 by being supported by the film 40 fixed to the inner wall of the upright chamber 12. This saddle layer 38 is composed of a plurality of saddles and constitutes a wide evaporation surface.

In the second upright chamber 14, a plurality of reflux cooling coils 42a, 42b, 42c are provided in the longitudinal direction. In the upright chamber 14, a plurality of filters or regeneration films 44a, 44b, 44c are arranged in the longitudinal direction between the cooling coils 42a, 42b, 42c. The regenerated film or the filters 44a, 44b and 44c are tensioned in a zigzag shape by using felt cloths of vitreous fibers as upper and lower support bars 46a and 46b.

Each regeneration film 44 and the cooling reflux coil 42 underneath each form one reflux layer. In addition, the fan 48 is provided at the upper end of the upright chamber 14, and the outlet 50 of the fan 48 protrudes outward from the upper end of the upright chamber 14. The connection part 16 inclined substantially horizontally connects the lower end of the upright chamber 14 and the lower side wall of the upright chamber 12, ie, the saddle layer 38 and the solution tank 18. As shown in FIG. The liquid-liquid layer 52 is provided in the bonding surface of the upright chamber 12 and the connection part 16. This liquid-liquid layer 52 is comprised by the zigzag plate layer which makes an air vibrate back and forth in order to remove the droplet of the solution contained in the air which passes through this.

The apparatus described above is used to reconcentrate an aqueous solution containing an organic antifreeze agent such as higher alcohols having a boiling point higher than that of normal water.

The main purpose of the present invention is to concentrate economically with little loss of organic antifreeze. When used to spray air cooling coils as antifreeze, the concentration of the aqueous solution is approximately 50% to 80% or more. The solution is recycled and sprayed into the air cooling coil to prevent freezing of the coil.

In such a case, the solution absorbs moisture and makes the concentration lean. The spray solution enters the aqueous solution tank 18 of the upright chamber 12 by passing through the inlet 24 so as to maintain the constant amount of the aqueous solution 20 by adjusting the floating valve 22. Reconcentration of the nebulized solution mainly evaporates the water having a low boiling point by the antifreeze, so that it can enter the air inlet 11 and contain the upright chamber 12 in the descending air flow.

For this reason, the spray solution recycles the inside of the upright chamber 12 as follows. The pump 26 with the suction pipe 28 draws spray liquid from the bath 18 in the aqueous solution 20. The pump 26 has a discharge pipe 30 and a branch pipe 30 ', and the branch pipe 30' returns the concentrated antifreeze to an air cooler or the like (not shown, with proper adjustment), and the antifreeze requiring concentration is The discharge pipe 30 is sent from the top of the upright chamber 2 to the spray nozzle 32. The nozzle 32 sprays a spray solution onto the heating coil layer 36 heated by a medium such as steam. When the heating coil 36 is filled with a solution, the excess of the solution falls to the saddle layer 38 having a wide evaporation surface. In addition, the excess of the solution of the saddle layer 38 falls again and returns to the accommodation modification 18.

Air moves in the apparatus as follows. The bottom face 19 of the second upright chamber 14 having a fan 48 at its upper end is connected to the aqueous solution tank 18 of the first upright chamber 2 through a substantially horizontal connecting portion 16. The bottom face 19 is the bottom face of the connecting portion 16, and is inclined in the solution bath 18 direction so that the dropping solution flows into the solution bath 18. The fan 48 is located inside the top of the upright chamber 14 with the inlet 49 and the outlet 50 extends out of the upright chamber 14 so that the atmosphere is provided with the air inlet of the first upright chamber 12. In 11) it passes through the first upright chamber 12 and into the second upright chamber 14.

The atmosphere passes through the air filter 34 to remove impurities and then leaves the first upright chamber 12 past the spray nozzle 32, the heating coil 36 and the saddle layer 38. By heating this atmosphere and the recirculating solution, water has a lower boiling point than that of the antifreeze, thereby promoting the evaporation of water in the spray solution. Moreover, evaporation is further promoted by the evaporation surface with a wide saddle layer. This reconcentration solution falls from the saddle layer 38 to the bath 18.

However, the high humidity air still passing through the bottom of the saddle layer 38 contains about 3% of an antifreeze against a unit of pounds of water. Again, the loss with air is not beneficial. Here, the present invention provides a multi-layer reflux cooling recovery device to prevent such a loss of the antifreeze. That is, in the bottom of the first upright chamber 12, the high humidity air passes through the wave plate of the liquid crystal layer 52, and the air is vibrated by the wave plate of the liquid plate 50 to separate the solution from the air.

At this time, the air of high humidity enters the bottom of the second upright chamber 14 through the connecting portion 16. Here, this air contacts the reflux cooling coil 42a with the first fan. The cooling coil 42a cools the air of high humidity, and as a result, the air passing through the reflux chamber 41a on the cooling coil 42a generates liquid particles containing a primary antifreeze or an aerosol mist. Air containing this mist then passes through the first filter 44a. The filter 44a is made of an ultra-fine fiber felt cloth spread out in a zigzag tent by upper and lower support bars 46a and 46b.

These zigzag-shaped vitreous fiber filter cloths 44a extend to the bottom end portion 45a thereof. It is important that the material of this filter cloth 44a has affinity for liquid molecules and sufficient surface tension. The vitreous fibers have such affinity. The liquid molecules adhere to the vitreous fiber filter 44a to form a large droplet gradually by surface tension, and pass through the reflux chamber 41a and the first cooling coil 42a at the bottom end 45a of the filter 44a. It falls on the inclined bottom plate 19 of the connection part 16, and flows into the solution tank 18. FIG.

The moisture passing through the first vitreous fiber filter cloth 44a still contains some antifreeze and rises to the reflux cooling coil 42b with the second fan. The cooling coil 42b cools the humid air as in the case of the first cooling coil 42a. The mist of mainly antifreeze generated thereby passes through the second filter 44b which is the same as the first filter 44a. The liquid molecules adhere to the filter 44b, and the droplets gradually increase due to the surface tension and move downwards, and the first filter (through the reflux chamber 44b and the cooling coil 42b at the bottom end 45b of the filter 44b). Dropping on 44a) acts as reflux condensate to clean filter 44a and to ensure that no solution remains in filter 44a.

The air which has passed through the second filter 44b also contains some antifreeze and rises to the cooling coil 42c with the third fan provided in the third reflux chamber 41c. Air is also subjected to the same action as the previous step to form a mist containing an antifreeze, and when droplets are removed, the liquid molecules are removed by the filter 44c in the same manner as the previous step, and the liquid molecules are dropped on the filter 44b below. 44b) is washed and finally recovered to the solution tank 18. As air rises through the reflux cooling coils 42a, 42b, 42c and the filters 44a, 44b, 44c, the content of the antifreeze gradually decreases and condenses in the filters 44c, 44b, 44a. As the dew point temperature and vapor pressure in the reflux chambers 44a, 44b, 44c gradually decrease due to the reflux of one condensate, the steam entering the inlet of the fan 48 contains 0.24% of antifreeze per pound of water.

As described above, when the reflux cooling coil and the filter are continuously used in multiple layers, the recovery amount of the antifreeze agent gradually decreases toward the upper layer. Even the second layer of diesel oil can fully exhibit its function. Three layers are used when there is a need to specifically increase the effectiveness of the reconcentration, and in a minimum it is possible to combine more layers.

Next, the importance of changes in dew point temperature, vapor pressure, concentration and reflux and dilution in the reflux bed will be explained by the following examples.

The atmosphere was supplied to the air inlet 11 at a bulb temperature of 82.1 ° F. and a wet bulb temperature of 69.9 ° F. to achieve a dew point temperature of 63.8 ° F. and a relative humidity of 53%. Water vapor was fed to the heating coil layer 36 at 228.7 ° F. with an air-vapor temperature of 156.3 ° F. upwards from the saddle layer 38. Through the saddle layer 38, the bulb temperature of the air that evaporated the moisture was as far as 146.5 ° F. For this reason, the temperature of the spray solution 20 in the solution tank 18 was maintained at 133.9 degrees F, and this solution was recycled and sprayed to the heating coil 36 and the saddle layer 38. FIG.

After passing through the low liquid plate 52, the liquid is recovered to some extent, and then the steam in the reflux chamber 41a under the first cooling coil 42a has a dry bulb temperature of 130.4 ° F, a wet bulb temperature of 119.2 ° F, and a dew point temperature of 117.7 ° F. Humidity was 72%. The three reflux cooling coils 42a, 42b and 42c have a dry bulb temperature and a dew point temperature down to 125.1 ° F and 115.6 ° F as they pass through the first reflux coil 42a through an 81.7 ° C coolant. Relative humidity rose to 77%. Due to this temperature drop, the liquid in the air becomes a fog phase and contacted and adhered to the first filter 44a. The attached droplets gradually increase due to the surface tension, move downward along the filter 44a by gravity, fall on the inclined bottom surface 19 through the first cooling coil 42a at the bottom end 45a, and the solution tank. The droplets adhering to the filter 44a by the vapor pressure flowing into (18) are higher in temperature than water, and are mainly composed of higher alcohols.

The steam passing through the first filter 44a mainly contains some water or still higher alcohol, passes through the second reflux cooling coil 42b, and the dry bulb temperature and the dew point temperature are respectively 119.5 in the second reflux chamber 41b. Fahrenheit and 113.9 ° F were relative humidity 87%. Again, the aerosol mist formed by cooling adhered to the second filter 44b. In addition, it was collected and dropped to the bottom end 45b of the filter 44b, and moved to the first filter 44a through the second reflux cooling coil 42b.

These droplets have a lower antifreeze content than the droplets falling from the first filter 44a as mentioned before, so that the droplets formed in the second filter 44b clean the first filter 44a and at the same time The entire solution collected in the first filter 44a was made thin.

The action of these two increases the antifreeze recovery effect of the first filter 44a. A third reflux treatment was performed on the steam passing through the second filter 44b to reduce the loss of the antifreeze medium to a fraction of one percent (0.24%) per pound of water vapor. For this reason, the dry bulb temperature and dew point temperature of the air in the third reflux chamber 41c were 116.5 ° F. and 112.4 ° F., respectively, and the relative humidity was 89% by sending steam to the third reflux cooling coil 42c and cooling it. It was.

The aerosol-like mist formed by cooling gathers on the third filter 44c, becomes droplets, falls to the bottom end 45c of the third filter 44c, passes through the third cooling coil 42c, and passes through the second filter. Moved to (44b). The solution which had already been extremely thin in concentration washed the second filter 44b and, at the same time, leaned the entire solution collected therein. The action of both of these increased the antifreeze recovery effect of the second filter 44b.

As mentioned above, it is possible that the apparatus of the present invention is extremely effective for the reconcentration of an aqueous solution of an organic antifreeze agent having a boiling point higher than that of a normal water. Recovery is extremely effective and antifreeze can be regenerated.

The above embodiment can of course be modified within the scope of the invention. For example, in order to form a wide evaporation surface in the first upright chamber 12, a filler other than the saddle layer 38 may be used. The filters 44a-44c can also be used for materials other than vitreous fibers that have affinity for the liquid particles and sufficient surface tension.

Claims (1)

Means for evaporating an aqueous solution in the first upright chamber having a main body provided with a connecting portion connecting the first upright chamber with the air inlet at the top, the second upright chamber, and the first and second upright chambers. Of the aqueous solution tank, the injection means installed at the upper air inlet for injecting the aqueous solution to the evaporation means, a pump mechanism for sending the aqueous solution from the aqueous solution tank to the injection means is installed, a plurality of cooling coils and a filter for recovery in the second upright chamber Is installed alternately to form a multi-stage reflux layer, and means for evaporating the air at the air inlet of the first upright chamber, a connection portion, and a fan for suction through the multistage reflux chamber are installed. A device for concentrating an aqueous solution of agent.

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