JP4399083B2 - Flow method and flow apparatus for mixture - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and an apparatus for distributing and flowing a mixture of a liquid and a solid substance such as a beverage containing pulp into a plurality of tubes arranged in parallel in an outer shell of a shell and tube heat exchanger.
[0002]
[Prior art]
For example, when beverages such as juice and soup are produced industrially, it is common to heat sterilize the beverage using ohmic heating or a heat sterilizer using microwaves. However, these heat sterilizers have a high running cost and it is difficult to increase the sterilizing ability. On the other hand, a multi-tube heat exchanger with a structure in which multiple tubes are arranged in a shell called a shell and tube heat exchanger can easily control the sterilization temperature accurately and continuously at a low running cost. Since it can be sterilized while feeding, multi-tube heat exchangers are widely used for sterilizing beverages.
[0003]
[Problems to be solved by the invention]
However, when a mixture of liquid and solid material such as juice containing pulp is distributed and flowed into a tube of a multi-tube heat exchanger, the solid material stays at the tube inlet and becomes clogged. Even if it is not blocked or clogged, the flow rate is lowered, so the time for flowing through the tube is increased, resulting in thermal denaturation such as burning of solids.
[0004]
In order to avoid such a situation, it may be possible to install a fin or a stirring propeller on the transfer pipe and force the liquid to flow. However, if only such a fin or a stirring propeller is installed, the solid matter at the tube inlet will not be It is very difficult to completely prevent stagnation.
[0005]
Accordingly, an object of the present invention is to prevent solids from staying at the tube inlet when the mixture is distributed and flowed to a plurality of tubes arranged in parallel in the outer shell of the shell and tube heat exchanger. And to provide a device.
[0006]
[Means for Solving the Problems]
In order to achieve this object, in claim 1, a method of distributing and flowing a mixture of a liquid and a solid in a plurality of tubes arranged in parallel, wherein a back flow of the mixture is generated , It is characterized by absorbing the mixture flowing back and then gradually returning the absorbed mixture to prevent the solid matter from staying at the tube inlet.
[0007]
In the flow method of claim 1, as described in claim 2, the tube is disposed, for example, in an outer shell of a shell and tube heat exchanger capable of circulating a heat medium.
[0008]
In these flow methods according to claims 1 and 2, the mixture is, for example, a beverage such as fruit juice juice, and other liquids (including viscous materials, sols, etc.) and solids (including fibers) other than beverages. A mixture of In the flow methods according to the first and second aspects, the solid matter staying at the tube inlet can be separated from the tube inlet and dispersed in the liquid by generating a back flow of the mixture. In this way, by resuming the flow with the solids dispersed in the liquid, the mixture can be smoothly distributed and flowed to the tubes of the shell-and-tube heat exchanger while preventing clogging of the solids. Will be able to.
[0009]
According to a third aspect of the present invention, there is provided a device for distributing and flowing a mixture of a liquid and a solid material to a plurality of tubes arranged in parallel, and a liquid feeding means for flowing the mixture to the plurality of tubes, and the plurality of the plurality of tubes. And a buffer means for absorbing the backflow of the mixture upstream of the plurality of tubes. The backflow generation means generates a backflow of the mixture by pressurizing downstream of the tubes.
[0010]
In the fluidizing device according to claim 3, as described in claim 4, the tube is disposed, for example, in an outer shell of a shell and tube heat exchanger capable of circulating a heat medium. Moreover, as described in claim 5, a plurality of the shell and tube heat exchangers may be arranged in series. Further, as described in claim 6, one or more shell and tube heat exchangers are arranged between the buffer means and the backflow generating means. According to a seventh aspect of the present invention, the liquid feeding means includes a supply pump that sends a constant flow rate upstream of the buffer means, and a discharge pump that sends a constant flow rate downstream of the backflow generating means. I have.
[0011]
In these flow devices according to claims 3 to 7, a back flow of the mixture can be generated by pressurizing by the back flow generating means, and the solid matter retained at the tube inlet by the back flow is supplied from the tube inlet. It can be peeled and dispersed in a liquid. On the other hand, the back flow of the mixture generated in this way can be absorbed by the buffer means. In this way, by resuming the flow with the solids dispersed in the liquid, the mixture can be smoothly distributed and flowed to a tube such as a shell-and-tube heat exchanger while preventing the clogging of the solids. Will be able to.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram of a mixture flow device 1 according to an embodiment of the present invention.
[0013]
A heating unit 10 and a cooling unit 11 are disposed adjacent to each other, and a plurality of heating shell-and-tube heat exchangers 12 (hereinafter referred to as “heat exchangers 12”) are connected in series to the heating unit 10 through pipes 13. Similarly, a plurality of cooling shell and tube heat exchangers 15 (hereinafter referred to as “heat exchangers 15”) are connected in series via pipes 16 in the cooling unit 11. It has been. The heating unit 10 and the cooling unit 11 are connected by a hold tube 17, and the mixture a that is alternately sent through the heat exchanger 12 and the pipe 13 in the heating unit 10 is sent to the cooling unit 11 through the hold tube 17. Further, the heat exchanger 15 and the pipe 16 are alternately fed in the cooling unit 11.
[0014]
A tank 21 is connected to the upstream of the heating unit 10 via a supply pipe 20. In the tank 21, a mixture a of a liquid and a solid such as juice containing pulp is stored. The most upstream end of the supply pipe 20 is connected to the lower surface of the tank 21 so that the mixture a in the tank 21 flows into the supply pipe 20. The supply pipe 20 is provided with a supply pump 22 for supplying the mixture a at a constant flow rate. By operation of the supply pump 22, the mixture a in the tank 21 is supplied through the supply pipe 20 at a constant flow rate. Thus, the liquid is fed toward the heating unit 10.
[0015]
A branch pipe 25 provided so as to branch from the supply pipe 20 between the supply pump 22 and the heating unit 10 is provided with a buffer tank 26 as buffer means, and the air in the buffer tank 26 is supplied and exhausted. It is absorbed by the air supply / exhaust control mechanism 28 via the pipe 27. As will be described later, when the back flow of the mixture a occurs and the inside of the supply pipe 20 is pressurized, the mixture a flows from the supply pipe 20 into the buffer tank 26 via the branch pipe 25.
[0016]
A discharge pipe 30 is connected downstream of the cooling unit 11, and the mixture a that has passed through the cooling unit 11 flows into the discharge pipe 30 and is fed. The discharge pipe 30 is provided with a discharge pump 32 for feeding the mixture a at a constant flow rate equal to that of the supply pump 22 described above, and the operation of the discharge pump 32 causes the mixture a that has passed through the cooling unit 11 to pass through. The liquid in the discharge pipe 30 is sent at a constant flow rate and is appropriately sent to the next step.
[0017]
A branch pipe 35 provided so as to branch from the discharge pipe 30 between the discharge pump 32 and the cooling unit 11 is provided with a reverse flow pump 36 as a reverse flow generating means. The reverse flow pump 36 is driven by an actuator 37. Has been. The backflow pump 36 is, for example, a plunger pump that pressurizes the mixture a by a reciprocating motion of a piston or a diaphragm and generates a backflow of the mixture a in the discharge pipe 30. The actuator 37 is a hydraulic device, a pneumatic device, a feed screw mechanism, or the like, and may be any device that can provide the reverse flow pump 36 with the drive necessary to generate the reverse flow, and is preferably capable of adjusting the speed.
[0018]
FIG. 2 is an explanatory diagram of the heat exchanger 12 provided in the heating unit 10 and the heat exchanger 15 provided in the cooling unit 11, and FIG. 3 illustrates the heat exchanger 12 and the heat exchanger 15. It is a longitudinal cross-sectional view. In addition, since the heat exchanger 12 and the heat exchanger 15 have the same structure, it demonstrates with the same drawing for convenience.
[0019]
Each of the heat exchangers 12 and 15 has a configuration in which a plurality of tubes 40 are arranged in parallel in the outer body 41. Each tube 40 is provided so as to connect between the headers 42 and 43, and the mixture a flowing into the header 42 is distributed in each tube 40 and flows rightward in FIG. 2 and flows into the header 43. It has become. Heat medium supply / discharge ports 44 and 45 are formed on the upper and lower surfaces of the outer cylinder 41, respectively.
[0020]
In the heating unit 10, a high-temperature heat medium is circulated into the outer cylinder 41 through the supply / discharge port 45 through the supply / discharge port 44 in the heat exchanger 12. The surface of the tube 40 is always filled with a high-temperature heat medium, and the tube 40 is heated to a high temperature. Thus, in the heating unit 10, the mixture a is heated to a desired high temperature and sterilized while flowing in each tube 40.
[0021]
On the other hand, in the cooling unit 11, a low-temperature heat medium is circulated in the outer cylinder 41 through the supply / exhaust port 45 through the supply / exhaust port 45 in the heat exchanger 15, so that the inside of the outer cylinder 41 is always at a desired low temperature. The surface of the tube 40 is always in contact with a low-temperature heat medium, and the tube 40 is cooled to a low temperature. Thus, in the cooling unit 10, the mixture a is cooled to a desired low temperature while flowing in each tube 40.
[0022]
Now, in the flow apparatus 1 configured as described above, the supply pump 22 and the discharge pump 32 are operated. As a result, the mixture a in the tank 21 is fed at a constant flow rate through the supply pipe 20, and is first fed alternately through the heat exchanger 12 and the pipe 13 in the heating unit 10. In the heating unit 10, the mixture a is sterilized by being heated to a desired high temperature while flowing through the tube 40 of each heat exchanger 12. The mixture a sterilized in the heating unit 10 passes through the hold tube 17 and then is sent to the cooling unit 11 alternately through the heat exchanger 15 and the pipe 16. In the cooling unit 11, the mixture a is cooled to a desired low temperature while flowing in the tube 40 of each heat exchanger 15. The mixture a thus sterilized and cooled is sent at a constant flow rate in the discharge pipe 30 and is appropriately sent to the next step.
[0023]
Here, for example, when a mixture a of a liquid and a solid material such as juice containing pulp is fed, the solid material stays at the inlet of the tube 40 in each heat exchanger 12 and 15 and becomes clogged. Even if the flow of the mixture a is not disturbed or clogged, the flow rate of the mixture a decreases, so that there is a concern that the time for flowing through the tube 40 becomes long. In particular, in the case of the heat exchanger 12 for heating, if the time for flowing through the tube 40 becomes long, there is a concern that the solid material may undergo thermal denaturation such as scorching.
[0024]
Therefore, in the flow device 1, the mixture a is pressurized by the operation of the backflow pump 36, and the backflow of the mixture a is generated. Then, in the cooling unit 11, the mixture a flows backward from the discharge pipe 30, whereby a reverse flow occurs in the mixture a flowing through each exchanger 15 and the pipe 16. Similarly, in the heating unit 10, each heat exchanger 12 And a reverse flow is generated in the mixture a flowing through the pipe 13. Then, the solid matter staying at the inlets of the tubes 40 of the heat exchangers 12 and 15 can be separated from the inlets of the tubes 40 and dispersed in the mixture a filled in the headers 42 by this back flow. On the other hand, when the reverse flow of the mixture a occurs in this way, the inside of the supply pipe 20 is pressurized, and the mixture a flows into the buffer tank 26 from the supply pipe 20 through the branch pipe 25.
[0025]
Thus, by restarting the flow in a state where the solid matter is dispersed in the mixture a, each heat exchanger 12, 15 is prevented from clogging the solid matter at the inlet of the tube 40 of each heat exchanger 12, 15, and so on. 15 can smoothly flow the mixture a, and the mixture a is sterilized continuously. Note that the backflow of the mixture a generated by the operation of the backflow pump 36 is absorbed by the buffer tank 26, and thus does not affect the liquid feeding by the supply pump 22. For this reason, the mixture a in the tank 21 is always fed into the supply pipe 20 at a constant flow rate by the operation of the supply pump 22. In addition, the mixture a that has been sterilized and cooled in each of the heat exchangers 12 and 15 is always discharged from the discharge pipe 30 at a constant flow rate by the operation of the discharge pump 32, and is appropriately sent to the next step. Become. The mixture a absorbed in the buffer tank 26 is gradually returned to the supply pipe 20 by controlling the air pressure of the supply / exhaust control mechanism 28 when the flow of the mixture a is resumed. It is desirable to stabilize the pressure. Thus, according to the illustrated flow apparatus 1, the mixture a in the tank 21 is always kept at a constant flow rate while preventing the solid matter from being blocked at the inlet of the tubes 40 of the heat exchangers 12 and 15 by backflow. Can be supplied to the fluidizer 1 and the mixture a can be discharged from the discharge pipe 30 at a constant flow rate.
[0026]
As mentioned above, although preferred embodiment of this invention was illustrated, this invention is not limited to the form demonstrated here. For example, a stirring mechanism 50 may be provided at the inlet of each of the heat exchangers 12 and 15 as in the flow device 2 shown in FIG. In this case, as shown in FIG. 5, the stirring mechanism 50 has a configuration in which a plurality of (four in the illustrated form) spiral fins 52 are provided on the inner surface of a pipe body 51 having a hollow cylindrical shape with open ends. And good. The flow device 2 shown in FIG. 4 has the same configuration as the flow device 1 described above with reference to FIGS. 1 to 3 except that a stirring mechanism 50 is provided at the inlets of the heat exchangers 12 and 15. Therefore, redundant description is omitted by assigning common reference numerals. By using such a stirring mechanism 50, it is possible to generate a swirling flow with respect to the mixture a flowing from the inlet side 51a to the outlet side 51b of the pipe main body 51. It is possible to reduce the retention of the product and extend the timing for removing the retention of the solid material. As a result, the interval at which the backflow pump 36 is operated can be extended.
[0027]
1 and 4 show an example in which a plurality of heat exchangers 12 and 15 are connected in series. However, it is not always necessary to have a plurality of heat exchangers 12 and 15, for example, as shown in FIG. As with the flow device 3, only one heat exchanger 12 (or 15) may be provided. The flow device 3 shown in FIG. 6 has the same configuration as the flow device 1 described above with reference to FIGS. 1 to 3 except that it includes only one heat exchanger 12 (or 15). Therefore, redundant description is omitted by assigning common reference numerals. As described above, similarly to only one heat exchanger 12 (or 15), the heat exchanger 12 (or 15) is prevented while blocking the solid matter at the inlet of the tube 40 of the heat exchanger 12 (or 15). ) Can smoothly flow the mixture a, and the mixture a is heated (or cooled) continuously.
[0028]
Further, for example, in the flow devices 1 and 2 shown in FIG. 1 and FIG. 4, the branch pipe 25 connected to the buffer tank 26 is connected to the position of the hold tube 17 instead of the supply pipe 20, thereby cooling. The mixture a may be made to flow backward only in the portion 11. In this case, the heat exchanger 12 provided in the heating unit 10 may use another type of heat exchanger that is not a shell-and-tube heat exchanger. Further, for example, in the flow devices 1 and 2 shown in FIGS. 1 and 4, the branch pipe 35 connected to the backflow pump 36 is connected to the position of the hold tube 17 instead of the discharge pipe 30, thereby heating. The mixture a may be made to flow backward only in the portion 10. Similarly, in this case, the heat exchanger 15 provided in the cooling unit 11 may use another type of heat exchanger that is not a shell-and-tube heat exchanger.
[0029]
In any of the flow devices 1 and 2, the backflow by driving the backflow pump 36 may be generated periodically or irregularly. Further, the mixture a may be a mixture of an arbitrary liquid and a solid, in addition to juice containing pulp.
[0030]
【Example】
Next, examples of the present invention will be described.
(Example 1) Continuously sterilized carrot of chopped carrot A mixture of 10% 5 mm square carrot dispersed in a 0.5% aqueous solution of carboxymethylcellulose (CMC) has a pressure of 0.3 MPa at the heating section and a discharge amount of 300 l / Sterilized continuously under the conditions of h. Back flow was generated about every 20 seconds. As a result of observation through observation windows arranged at positions (a), (b), (c), and (d) in FIG. 1, a backflow of the mixture was confirmed. In addition, the outflow of solid matter was not confirmed at the time of washing the apparatus after completion of sterilization, and the remaining solid matter was not confirmed even after decomposition after washing. It was confirmed that clogging of solid matter during sterilization was removed.
[0031]
On the other hand, the temperature at the time of sterilization may not be stable due to the occurrence of backflow, so the temperature of the mixture is controlled by the temperature sensors placed at the positions (e), (f), (g) and (h) in FIG. It was measured. As a result, as shown in FIG. 7, the temperature fluctuation before and after the occurrence of the backflow was small, and the temperature at the particularly important hold tube inlet hardly changed. In addition, the pressure change of the mixture measured with the pressure sensor arrange | positioned in the position of (ri) in FIG. 1 was combined with FIG. 7, and was shown.
[0032]
(Example 2) Continuous sterilization of mandarin orange granules A mixture of 30% mandarin orange granules dispersed in a 0.5% aqueous solution of carboxymethylcellulose (CMC) was heated at a pressure of 0.2 MPa and discharged at 300 liters / h. Sterilized continuously under conditions. Back flow was generated about every 20 seconds. Similarly, as a result of observation through the observation window, a backflow was confirmed, and no solid spilled out during the cleaning of the device after the sterilization, and no solids remained in the decomposition after the cleaning. Confirmed that it was removed.
[0033]
【The invention's effect】
According to the first to seventh aspects, the solid matter staying at the tube inlet can be dispersed by the back flow of the mixture, and the mixture is transferred to the tube of the shell and tube heat exchanger while preventing the solid matter from being blocked. Distribute and flow smoothly. For this reason, the mixture can be sterilized stably and continuously.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a flow device according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram of a heat exchanger.
FIG. 3 is a longitudinal sectional view of a heat exchanger.
FIG. 4 is an explanatory diagram of a flow device provided with a stirring mechanism at the inlet of each heat exchanger.
FIG. 5 is a perspective view of a stirring mechanism in which spiral fins are provided on the inner surface of a pipe body.
FIG. 6 is an explanatory diagram of a flow device including only one heat exchanger.
FIG. 7 is a graph showing changes in temperature and pressure over time in an example of the present invention.
[Explanation of symbols]
a Mixture 1, 2, 3 Fluidizer 10 Heating unit 11 Cooling unit 12, 15 Heat exchanger 13, 16 Pipe 20 Supply pipe 21 Tank 22 Supply pump 25 Branch pipe 26 Buffer tank 27 Supply / exhaust pipe 28 Supply / exhaust control mechanism 30 Discharge Pipe 32 Discharge pump 35 Branch pipe 36 Backflow pump 37 Actuator 40 Tube 41 Outer trunk

Claims (7)

A method of distributing and flowing a mixture of a liquid and a solid in a plurality of tubes arranged in parallel,
Flow of the mixture, characterized by generating a backflow of the mixture, absorbing the backflowed mixture, and then gradually returning the absorbed mixture to prevent solids from staying at the tube inlet. Method.   2. The method of flowing a mixture according to claim 1, wherein the tube is disposed in an outer shell of a shell and tube heat exchanger capable of circulating a heat medium. A device for distributing and flowing a mixture of liquid and solid material in a plurality of tubes arranged in parallel,
Liquid feeding means for causing the mixture to flow in the plurality of tubes, backflow generating means for generating a backflow of the mixture by pressurization downstream of the plurality of tubes, and a buffer for absorbing the backflow of the mixture upstream of the plurality of tubes A flow apparatus for the mixture, characterized in that it comprises means.   4. The apparatus according to claim 3, wherein the tube is disposed in an outer shell of a shell and tube heat exchanger capable of circulating a heat medium.   The flow apparatus of the mixture according to claim 4, wherein a plurality of the shell and tube heat exchangers are arranged in series.   6. The mixture flow apparatus according to claim 4, wherein one or more shell and tube heat exchangers are arranged between the buffer means and the backflow generating means.   4. The liquid feeding means comprises a supply pump for feeding at a constant flow rate upstream of the buffer means, and a discharge pump for feeding at a constant flow rate downstream of the backflow generating means. , 4, 5 or 6 mixture flow device.

Images