JPS63305993A - Bioreactor - Google Patents

Abstract

PURPOSE:To enable efficient reactions with a small-sized reactor, by raising internal pressures on the filter surface utilizing gas pressure inside a reactor body and keeping the outside pressure on the filter membrane close to the internal pressure of the reactor body, thereby reducing the internal pressure of the filter membrane when liquids flow therethrough. CONSTITUTION:A enclosed vessel-like reactor 1 with a raw material feed pump 2 connected to the lower part thereof and an inner liquid outlet 3 is provided with a control valve 5 to keep internal pressure in the reactor 1 at a certain level. Further, a liquid flow pump 9 leading to a filter structure comprising filter membranes 8 having small pores is provided so that the filtered liquids outside the membranes of the filter structure is guided to a gas-liquid separator 10 provided separately and a line 17 to return the liquid inside the membranes into the reactor 1 is provided. A valve 19 with an electromagnetic mechanism to open and shut the line 17 and a separate bypass pipe 20 are provided in the line 17, a pressure regulating valve 21 to reduce, at any time, internal pressure caused by liquid flow being provided in the bypass pipe 20. Consequently, efficient reaction can be performed with a small-sized reactor.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a bioreactor that efficiently decomposes water-soluble organic waste containing a large amount of solid matter and soluble organic matter using anaerobic bacteria.

Conventional technology Up until now, bioreactors have been constructed by housing anaerobic bacterial cells in a sealed container-like reactor body filled with a raw material liquid together with a carrier made of a porous material with a particle size that allows the bacterial cells to easily adhere. It is a common method that decomposes waste by stirring and concentrating it to increase the concentration of anaerobic bacteria while supplying a raw material solution, and it is usually equipped with a stirring device inside the main reactor and a device that brings the bacteria into contact with the carrier. It is formed by attaching a concentrating device to the reactor main body.

Problems to be Solved by the Invention However, in the above-mentioned conventional apparatus, the internal liquid is stirred by a stirring rock, then the internal liquid is taken out and concentrated, and the raw material liquid is replenished accordingly. Because of this, it was difficult to expect efficient work, and the overall size of the device was disadvantageous. The present invention has been made to improve the drawbacks of such conventional bioreactors.

Means for Solving the Problems In order to develop a small bioreactor that can carry out efficient reactions, the present inventors have conducted intensive research and have developed a special filtration membrane inside or outside the reactor itself. is provided, and the gas pressure generated within the main body of the reactor is used to increase the internal pressure on the surface of the filtration membrane when the liquid flows, and the external pressure of the filtration membrane is kept close to the internal pressure of the main body of the reactor.
It was discovered that the objective could be achieved by reducing the internal pressure when the liquid flows inside the filtration membrane and simultaneously stirring the liquid inside the main body of the reactor, and based on this knowledge, the present invention was developed. I arrived at the eggplant.

That is, the present invention provides a reactor main body in the shape of a closed container with a raw material supply pump near the bottom and an internal liquid outlet at the bottom, a control valve that maintains the internal pressure inside the reactor main body at a constant level, and a microporous filtration membrane. A liquid flow pump is provided to connect the filtrate on the outer surface of the membrane of the filtration mechanism to a separate gas-liquid separator, and a pipe line is provided to return the liquid on the inner surface of the membrane into the reactor main body. A bioreactor is constructed by providing a valve with an electromagnetic mechanism for opening and closing the pipeline, a bypass pipe separate from the above-mentioned valve, and a pressure regulating valve attached to this bypass pipe to reduce the internal pressure at any time when the liquid is flowing. This is what we provide. -Example Next, an example of the present invention will be explained with reference to the drawings.In Fig. 1, 1 is the main body of the reactor, which is made as a cylindrical sealed container, has a raw material supply pump 2 near the bottom, and a pump for taking out the internal liquid at the bottom. The valve 3 has a control valve 5 with a pressure switch 4 for draining the gas on the upper part. Furthermore, a cylindrical filtration membrane 8 is provided inside the cylinder 6 provided through the reactor main body 1, surrounding the hollow tube 7, and a liquid flows through the pipe line connecting the hollow tube 7 and the reactor main body 1. A pump 9 is attached. Since the filtration membrane 8 contains soluble gas, a gas-liquid separator 10 is attached to it, and this gas-liquid separator has an on-off valve 12 connected to a liquid level control mechanism 11 because it is necessary to keep the liquid level constant.
, and an electromagnetic mechanism 13 for taking out the gas in the gas-liquid separator.
A control valve 14 and a control valve 16 with a pressure casing inch 15 are respectively provided.

Furthermore, a valve 1 with an electromagnetic mechanism or an electromagnetic mechanism 18 is provided in the conduit 17 connecting the upper end of the hollow tube 7 and the inside of the reactor main body 1.
9 and a bypass pipe 20, a manually operated pressure regulating valve 21 is provided thereto to open and close the pipe line 17.

FIG. 2 shows a modification of FIG. 1, in which the filtration device consisting of the inner cylinder 6, hollow tube 7, and filtration membrane 8 in FIG. 1 is formed as a disk-shaped filtration membrane 8' in FIG. There is.

The pond area is indicated by the same reference numerals as in Figure 1.

Functions and Effects This invention increases the filtration rate by increasing the internal pressure on the surface of the filtration membrane using the gas pressure inside the reactor main body 1, and by controlling the pressure of the gas separated from this filtrate, the filtration membrane increases. By increasing the pressure on the surface side and controlling these as well as the outlet side pressure of the filtered fluid fluid, that is, the static pressure during fluid flow by the fluid fluid pump 9, the fluid inside the reactor main body 1 can be increased. It is capable of performing stirring and filtering alternately, and in order to achieve this purpose, a bypass pipe 20 is installed at the filtration membrane outlet, a pressure regulating valve 21 is provided on this, and a A valve 19 consisting of a solenoid valve or an electric valve is installed to open and close this pipe. In other words, during stirring and filtration, the liquid in the reactor main body 1 is passed through the filtration membrane 8 (
8'), and a positive pressure P2 is generated, and the magnitude of the pressure at this time is determined by the opening/closing of the lift of the liquid flow pump 9, the diameter of the bypass pipe 20, and the opening degree of the pressure regulating valve 21. Now, if the internal pressure inside the reactor main body 1 is P, the internal pressure at the outlet of the liquid flow pump 9 is P2, and the pressure inside the gas-liquid separator 10 is P3, (1) The pressure control of P3 in the operation of the liquid flow pump is as follows. It is as follows.

(b) Timely: Open the valve 14 so that the pressure at P2-P3 becomes from several atm to several tens of atm, and the pressure at P3 becomes close to normal pressure.

(b) During stirring: Close the valve 14 so that the internal pressure on the filtration membrane surface is approximately equal to the external pressure. Therefore, the pressure switch 15 is determined so that p3=p, +p2 and the opening degree of the control valve 16 becomes P3=P1+P2.

(2) When the liquid flow pump is in operation, the P2 pressure is controlled as follows.

(a) Timely filtering: Close one valve and slightly open the pressure regulating valve 21 so that P2 pressure is generated.

(b) When stirring: Open the valve 19 to prevent the P2 pressure from becoming too high.

(3) When the liquid flow pump is not operated, select either (a) valve 14 closed or valve 19 open (b) valve 14 closed or valve 19 closed during the flow rest period when neither stirring nor filtration is performed. , differs depending on the gas generation rate of the raw material in the filtration membrane, and when the generation rate is high, (1) is taken, and when it is low, (2) is taken, but it also differs depending on the rest time.

(4) Since the filtrate contains soluble gas, remove the gas-liquid separator to separate the gas and liquid. Since it is necessary to keep the liquid level constant in this device, the valve 3 is turned OFF by the liquid level control device.

(5) The raw material is supplied in an amount equal to or in direct proportion to the flow rate of the amount of filtrate.

(6) Since the P1 pressure at the time of startup of this device is close to normal pressure, the amount of filtrate will be small at this time. Therefore, since the supply of raw materials is reduced, low-load operation is automatically performed and operation is on the safe side. Further, if for some reason gas generation deteriorates and the pressure inside the reactor main body 1 decreases, the amount of raw material supplied will also decrease, making the operation of the apparatus safe.

(7) If the gas amount and gas pressure are sufficient and the amount of filtrate is small, the filtration membrane may be clogged.

Therefore, by collecting these data, it is possible to know when to replace the filtration membrane.

As explained above, the present invention equips the reactor with a filtration device consisting of a special membrane that separates bacterial cells, solid matter, and high-molecular organic matter, and in order to increase the filtration rate, the gas generated within the reactor By using pressure, the internal pressure of this membrane surface is kept high by adding the necessary pressure when the liquid flows, and the external pressure of the membrane is kept close to the reactor internal pressure, so that the internal pressure inside the membrane surface when the liquid is flowing is kept high. By making it small, it is possible to stir the liquid inside the main body of the reactor and prevent contamination and deterioration of the membrane surface by bacterial cells. These pressures are controlled by the valves attached to the main body of the reactor and the valves installed on the outlet side of the membrane, so in this way the pressure inside the main body of the reactor can always be kept higher than normal pressure. Therefore, among the gases decomposed and generated by anaerobic bacteria, soluble gases can be confined in the liquid phase, making it possible to increase the concentration of insoluble gases. Ammonia generated by bacterial decomposition easily reacts with this soluble gas, thereby alleviating the inhibition of the growth rate of anaerobic bacteria. In addition, the filtration membrane collects anaerobic bacteria within the reactor main body, and low-molecular substances such as ammonia are separated outside the reactor main body, so inhibition by these substances is reduced and the anaerobic bacteria within the reactor main body are It becomes possible to increase body concentration in a short time. This allows for very high substrate consumption rates and maintains high organic loadings.

Furthermore, in order to increase the concentration of bacterial cells within the main body of the reactor, a special porous antibody with a particle size of about 0.3 to Iaov to which bacterial cells easily adhere was added to the reactor's effective volume.
By adding ~30% and allowing it to flow, it is possible to further increase the bacterial cell concentration, making it possible to apply a very large organic load to the reactor and to significantly reduce the device volume. .

[Brief explanation of the drawing]

FIG. 1 is an explanatory cross-sectional view showing an embodiment of the invention, and FIG. 2 is an explanatory cross-sectional view showing a modification of FIG. 1...Reactor main body, 2...Raw material supply pump, 3
... Valve for taking out internal liquid, 5, 16 ... Control valve, 6
...Inner cylinder, 7...Hollow tube, 8,8'...filtration membrane,
9... Liquid flow pump, 10... Gas-liquid separator, 19.
...Valve, 20...Bypass pipe, 21...Pressure regulating valve

Claims (1)

[Claims] 1. The main body of the reactor is a sealed container with a raw material supply pump near the bottom and an internal liquid outlet at the bottom, and a control valve that maintains the internal pressure within the main body of the reactor at a constant level, and a filtration mechanism consisting of a microporous filtration membrane. A continuous liquid flow pump is provided to connect the filtrate on the outer surface of the membrane of the filtration mechanism to a separate gas-liquid separator, and a pipe line is provided to return the liquid on the inner surface of the membrane to the main body of the reactor. A bioreactor comprising a valve with an electromagnetic mechanism for opening and closing the valve, a bypass pipe separate from the valve, and a pressure regulating valve attached to the bypass pipe to reduce the internal pressure at any time when the liquid is flowing.