DE1054099B - Liquid cooler for direct evaporation of oil-absorbing refrigerants, such as fluorinated hydrocarbons, in double-pipe design - Google Patents

Description

It is in the course of technical development, liquids such as wine, milk, beer, mediating direct refrigerant evaporation, the advantage being seen in that it is corrosive Brine, dirty fresh water and other expensive cold transfer media can be avoided and by direct refrigerant evaporation makes operation more economical.

If ammonia is used as the refrigerant, the cheapest version is the tubular boiler evaporator as the lubricating oil will separate from and be separated from the ammonia can. When operating with direct evaporation of oil-dissolving refrigerants such as fluorinated hydrocarbons, it is not possible to use tubular boiler evaporators, as this is the case with the liquid Introduced oil cannot be sucked off and the oil concentration increases constantly. For evaporators, which are charged with fluorinated hydrocarbons, it is therefore common to use them as coil evaporators to be connected in series so that the oil can be carried away with the steam flow up to the compressor. According to the invention, this type of circuit is to be applied to the liquid cooler.

Fig. 1 shows the overall picture of such a cooler in longitudinal section and

Fig. 2 in cross section.

This is designed as a double pipe cooler with a number of superimposed double pipes from which the inner tubes 1, the medium to be cooled, the jacket tubes 2 in the remaining sickle-shaped Room 3 carries the refrigerant, fluorinated hydrocarbons. The jacket pipes are on the refrigerant side all connected in series, in such a way that injected with a pipe lying in the lower half is that the refrigerant is then passed back and forth through the overlying pipes upwards and is directed from the top pipe to a pipe below and on this occasion takes place for the final evaporation of the oil. The total number of superimposed tubes as well the division into upward and downward pipes must be adapted to the respective conditions. Other refrigerant circuits are also conceivable, e.g. B. pure downward flow of the refrigerant or also pure upward flow of the refrigerant, if the velocities of the refrigerant vapor are calculated in this way that the entrainment of the oil is guaranteed.

The liquid-carrying pipes 1 are connected by bends 4 as usual, the bends can be removed for cleaning the inner surfaces in contact with the liquid.

This ensures that the heat transfer fluid cooler

for direct evaporation of oil-dissolving refrigerants such as fluorinated hydrocarbons, in double tube design

Applicant:

Bergedorfer Eisenwerk Aktiengesellschaft

Astra works,
Hamburg-Bergedorf

Dipl.-Ing. Friedrich Leopold, Hamburg-Bergedorf,
has been named as the inventor

Wherever possible, the surfaces are immersed in the liquid refrigerant and as little as possible in the refrigerant vapor, according to the invention, the liquid-carrying inner tubes are to be eccentric, namely offset downwards be installed in the casing pipes.

Displacers 6 are inserted loosely and removably into the liquid-carrying pipes 1. These have a multiple task:
1. To increase the heat transfer, the liquid velocity in the remaining annulus should be increased between 1 and 6 if possible.

2. In order to increase this effect even more, the displacers can be provided with surfaces 7 that generate swirl which also serve to center the displacer.

3. Because the displacers are removable, the inner surfaces are easy to clean facilitated, especially since the tubes 1 can be designed with an enlarged diameter.

4. If the displacement tubes are made relatively thin-walled, they protect the liquid and heat transfer tubes 1 from destruction if due to inattention operator should freeze the cooler. In this case, the pipes 1 destroyed, but the displacer 6 can move inward.

5. Displacers of different diameters can be inserted in the same cooler. Man can adjust the cooler to different cooling conditions. For example, a cooler can with a certain given cooling surface the cooling

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transfer power of 10,000 Kcal. But there is a difference whether one z. B. 1000 1 liquid wants to cool by 10 ° or 50001 liquid by 2 °. In the former case, a sufficiently high flow rate smaller cross-sections necessary. So you become one here Insert a thicker displacer than for the larger amount of liquid.

As the description reveals, the present invention is a combination characteristics known per se, but their joint application guarantees a surprising success insofar as the following simultaneously existing advantages are achieved:

Compared to a tubular boiler evaporator, only very small ^{amounts of refrigerant are required, an A 7} component, which is particularly important for fluorinated hydrocarbons due to the high price. The use of oil-dissolving, fluorinated hydrocarbons has only become possible in the case of liquid coolers thanks to the series connection of the pipes, whereby the advantages of non-flammability and the non-toxicity of such refrigerants should also be pointed out, which make their use particularly desirable in food processing plants. If there is a risk of leaks, the non-toxicity is extremely valuable, especially when refrigerating food.

The ability of such a cooler to be regulated quickly by injecting more or less refrigerant is another benefit. Such a control works with the usual tube boiler evaporators considerably slower due to the large quantities of refrigerant available.

Related to this is the prevention of the risk of freezing, especially with milk and beer and wine is very large, as these drinks should be cooled to close to their freezing point.

The great adaptability of the cooler to the

different flow rates with constant heat transfer performance increases the practical usability very strong and allows a cheaper series production of such coolers.

All in all, the cooler according to the present invention is a considerable technical one ίο Progress with surprisingly good effects and a considerable increase in profitability and operational readiness.

Claims (2)

PATENT APPROACH: 1. Liquid cooler for direct evaporation of oil-dissolving refrigerants such as fluorinated hydrocarbons, in double pipe design, characterized by the simultaneous use of the following well-known design features: series connection of the refrigerant-carrying Shell spaces between inner and outer tube, inner tube offset eccentrically downwards, removable Elbows, removable, thin-walled displacers inserted into the inner tubes. 2. Liquid cooler according to claim 1, characterized in that on the surface of the displacer vortex or swirl-generating liquid guides sit. Considered publications: German Patent No. 868,746;
British Patent No. 178,904;
U.S. Patent No. 1,920,570. 1 sheet of drawings