FI56775C - ANORDNING FOER FOERGASNING AV VAETSKOR - Google Patents

Description

E3SCT Γβΐ m) NOTICE, SU

Ma lBJ (11) UTLÄGCNINGSSKRIFT 567/5 C and Patentti yJnr .'- tty 10 J4 1900 Patent meddelat VT ^ (51) Kv.ik.a / int.a. 'B 01 F 3/04 SUOMI — FINLAND (21) P * Mnttlhik * mu * - Patenunsttknin | 3 ^ 27/73 (22) Hakemlipllv »- Antöknlnj» d »f 06.11.73 (23) The beginning of the cloud - Glltightttdtg 06.11.73 (41) Become public - Bllvlt offentllg 02.06.7 ^ + _. ^ '. . (44) Date of dispatch and of issue of the publication. - οη Ί 0

Patent · och registerstyrelien Ansökan utlagd och utl.skrlftan publlcerad dl. ± 2.79 (32) (33) (31) Requested request * —Begird priorltet 01.12.72 08.06.73 Switzerland-Switzerland (CH) 17630/72 81 + 28/73 Proven-Styrkt (71) (72) Hans Muller, Alte Landstrasse 1 + 15, CH-8708 Männedorf, Switzerland-Switzerland (CH) (7 * +) Forssen & Salomaa Oy (5I *) Equipment for gasification of liquids - Anordning for förgasning av vätskor

The invention relates to a device for gasifying liquids by means of an axially suction centrifugal pump. The device specifically serves aeration in aerobic microbiological processes, how it is utilized in the manufacture of antibiotics, in the cultivation of microorganisms in special and chemical gas reactions in general.

For example, it is known that the more aeration in aerobic fermentation takes place, the better growth of the above-mentioned microorganisms can be achieved.

It is also known that the smaller the gas bubbles, the stronger the gas / liquid diffusion. Such arrangements are described in German Patents 579,141 and 920,844. These patents assume that a relatively homogeneous substance must be gasified, which is not always the case. For example, the gasification of a substance containing yeast takes place in a completely different way from the gasification of a substance containing penicillin (Mycel), for example, without taking into account the fact that it is in no way a Newtonian liquid. Gasification pumps have also been manufactured in which air or gas is self-aspirated by arranging gas inlets on the outer circumference of the pump wheels, which self-extract this gas by means of the speed of the pump wheel (H.J. Rehm, Industrielle Mikrobiologie, p. 66, Berlin, Heidelberg, New York 1967). Such aeration devices have the disadvantage that the impellers or impellers must have a relatively high speed and, with the high viscosity of the liquid B 01 F 5/16, C 12 B 1/16 2 56775, they no longer function or only function poorly. The suction height of air or gas is low and cannot be monitored.

According to the invention, there is provided an improved mechanical device for aerating various cultures which must be aerated with air or some other gas.

The device according to the invention suitably consists of a centrifugal pump with a hollow shaft, with an axially suction, closed impeller having a venturi-like narrowing at the inlet and suction openings for gas at the narrowest point. These openings are at the smallest inflow cross-section and thus at the largest possible vacuum. These inlets can be connected either via the hollow shaft of the pump to the outside air or to the gas sucked from the outside or to the upper surface of the gas space above the liquid, respectively. Depending on the cross-section of the venturi-like suction pipe and the speed of the pump, the highest possible suction heights or gas volumes can be achieved.

It has been found that in gas reactions such as fermentation, liquid / gas dispersions are formed in the device, which depend on the specific gravity of the dispersion. The higher the absolute amount of gas relative to the amount of liquid in the dispersion, the more the suction amount of the gas to be mixed and its suction height vary. In order to achieve the optimum gas suction head and suction volume, i.e. with the lowest possible power requirement, the suction cross-section at the impeller inlet can be changed. Likewise, by changing the transport volume of the impeller, the amount of air drawn in and the amount of liquid to be recycled can be adapted to the respective needs. The higher the circulation rate and the smaller the cross-section, the higher the gas suction volume and, respectively, the suction head and the circulating liquid volume. The aim is to be able to vary these amounts for a given process in order to keep the power requirement, which is partly directly related to the reaction, as low as possible.

It is very difficult to say these parameters in advance for certain processes and therefore an embodiment of the device according to the invention was developed which can be adapted to these requirements.

A special embodiment consists in that both the dimension of said venturi-like inlet pipe of the pump and the total amount circulating through the pump are made adjustable. Both of these adjustments are possible independently of each other, i.e. the inflow opening at the venturi inlet and the transport volume of the pump. For example, certain reactions require a high suction head with a high rotation at the same time. In this case, the venturi opening is kept as small as possible so that the largest possible flow and the highest possible vacuum are generated at the gas inlet. If a lower head is allowed at the same suction head of 56775, the venturi inlet is selected to be lower and also the pump speed. However, if, for example, the circulating liquid has a high tendency to foam, the specific gravity of the circulating dispersion decreases so that the pump delivery must be increased for the same suction head. For this purpose, the width or diameter of the impeller is changed to compensate for the lower suction head.

The invention also relates to the use of the device described above in a spherical reaction boiler.

Namely, it has been shown that the described device works very well in a spherical reaction boiler. With the selected shape, for example, at half-filling, the ball forms a larger flow volume than a cylinder of the same height.

This plays an essential role in overcoming hydrostatic pressure in self-priming. The advantage is the higher filling of the spherical boiler compared to the traditional boiler. The shape of the top surface also has a favorable effect on the disposal of the foam formed. In addition, due to the smaller surface area of the ball and favorable stability ratios, less and thinner material is required. The savings are a third compared to traditional boilers.

In addition, due to the larger filling volume, more cooling elements can be placed inside the boiler. This is a great advantage in exothermic reactions during the aerobic growth of microorganisms.

The invention will be explained in more detail with reference to the accompanying drawing.

Figure 1 shows the device in its simplest embodiment.

Figure 2 shows an embodiment of a pump with the possibility of adjustment.

Figure 3 shows such a gasification pump in connection with a reaction boiler.

Figure 4 shows a further embodiment of Figure 3.

Figure 1 shows the device in its simplest embodiment. Attached to the hollow shaft 1 is a pump impeller consisting of a hub part 4, a plate 3 screwed to it and provided with vanes 14 and a main plate 2 screwed to the plate 3. The plates 2 and 3 form the side walls of the flow channels of the pump wheel.

With the rotational movement of this pump wheel, the circulating liquid is sucked into the opening 5, 4 567 / s of the main plate 2, whereby the maximum velocity of the liquid is generated in the venturi-like suction pipe, i.e. at the point where the gas inlets 6 are arranged in the pole part 4. The sucked gas thus enters the hollow shaft 1 7 and flows through the intermediate openings 8 and the gas inlets 6 ·

Fig. 2 shows a similar embodiment of the pump, in which the distance 9 between the side walls 2 and 3 of the pump can also be changed, and this change is to increase and decrease the total flow rate. At the same time, by adjusting the entire pump unit 2,3, which takes place by moving the hub part 4 on the shaft 1 with the screws 10 open, the distance 11, i.e. a flow opening in the venturi-like inflow tube. The flow rate, suction head and gas volume can thus be varied.

In order to better disperse the gas into the liquid, the outer circumference, i.e. the outlet of the pump wheel is provided in a known manner with a tube with openings, a baffle plate, etc., which have the function of reducing gas bubbles at the outlet of the pump.

The described devices can be mounted as a single or multiple implementation on a horizontal hollow shaft in a horizontal reaction boiler. Such structures have the advantage that relatively low suction heights are sufficient for proper aeration of large production volumes. On the other hand, such pumps can be installed as separate devices with a drive motor in reactors lying and standing on different sides.

Figure 3 shows such a gasification pump with a suction pipe 17 projecting into the boiler. If the dispersion in the reaction boiler tends to separate by flotation while transporting the slurry particles to the top surface of the liquid, the liquid (12) can be sucked from the top of the boiler and the gas 13 from outside.

Figure 4 shows a vertical section of a spherical reaction boiler in which a pump wheel is mounted by means of a flange. Air enters the reaction boiler through the suction pipe 13 and leaves it through the mechanical foam separator 18. The devices 19 act as coolers during fermentation.

Claims (3)

5 r - .. b o / / Is A ball user having a gasification device for a base fluid in aerobic, microbiological processes, the device consisting of an axially aspirating, closed centrifugal pump impeller mounted on a hollow shaft through which the incoming gas can be introduced into the impeller through the gas inlet openings, wherein it can be mounted in a tank, or a horizontal reaction boiler with one or more gasification devices for a base fluid mounted on a horizontal hollow shaft in aerobic microbiological processes, consisting of an axially aspirating closed centrifugal pump impeller, or lying or standing reactors with in processes consisting of an axially aspirating closed centrifugal pump impeller, whereby the centrifugal pump, arranged in one unit with the drive motor, can be mounted in series; ktor, characterized in that the impeller inlet for the liquid has a venturi-like constriction (5) with suction openings (6) for the gas to be introduced into the base liquid at the narrowest point. User according to Claim 1, characterized in that the impeller has distance-adjustable side walls (2,3) for adjusting the flow rate. User according to Claim 1 or 2, characterized in that by moving the hub part (4) on the hollow shaft (1) with the screws (10) open, the flow opening of the venturi-like constriction (5) can be changed.