JP2005194492A - Apparatus and method for producing polyol composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for producing a polyol composition which can use an opened tank and a pressure tank and prevent the gasification of a foaming agent of a low boiling point mixed in the polyol composition so that the foaming agent of a low boiling point is not pressurized to more than a prescribed value. <P>SOLUTION: The apparatus comprises a tank 1 for storing the polyol composition, a circulation passage 2 for returning the polyol composition fed out from the tank 1 again into the tank, a circulation pump 8 for circulating the polyol composition in the passage, and a foaming agent charging passage 3 for charging the foaming agent of a low boiling point at a confluence position A set on the downstream side of the pump 8, a pressure sensor 7 which is set on the upstream side of the pump 8 and the first pump control unit 22 for controlling the number of revolution of the motor of the pump 8 that the pressure detected on the basis of the detection results of the pressure sensor 7 is a prescribed value, and in the circulation passage 2, the foaming agent of a low boiling point is mixed gradually while the polyol composition is circulated. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a production facility and a production method for a polyol composition which is a urethane stock solution for producing a urethane foam.

  Generally, a polyol composition (consisting of a polyol compound, a foam stabilizer, a catalyst, and a foaming agent) is used as a urethane stock solution for producing a urethane foam. In the production of the urethane stock solution, chlorofluorocarbon is suitably used as a foaming agent to be mixed with polyol, and HCFC-141b has been conventionally used. Since this conventional chlorofluorocarbon (HCFC-141b) has a boiling point of 32 ° C., it has been difficult to gasify under the outdoor temperature throughout the year. Therefore, an open tank (a tank in which the inside is in an atmospheric pressure state) can be suitably used as a tank used in a polyol composition production facility. That is, a polyol composition was produced by directly charging a polyol or the like as a urethane stock solution into an open tank, and further adding and mixing chlorofluorocarbon as a foaming agent directly into the open tank.

  However, there is currently a known problem that HCFC-141b causes the stratospheric ozone layer to be destroyed, and its use is regulated. Therefore, HFC-245fa, which is a low boiling point blowing agent, is used as an alternative chlorofluorocarbon to replace HCFC-141b. As equipment for producing a polyol composition using such an alternative chlorofluorocarbon, which is a low-boiling foaming agent, a mixing apparatus disclosed in the following Patent Document 1 is known. This mixing device includes a mixing device main body (pressure vessel), a polyol supply path, a polyol circulation path, and a low-boiling-point blowing agent supply path connected to the polyol circulation path. Then, the low-boiling-point blowing agent is supplied into the polyol from the low-boiling-point blowing agent supply path under a temperature and pressure sufficient to maintain the liquid state of the low-boiling blowing agent. Furthermore, a pressure vessel (pressure tank) is used as the mixing device main body, and gasification of alternative chlorofluorocarbon, which is a low boiling point blowing agent, is prevented.

  As described above, the mixing apparatus disclosed in Patent Document 1 uses a pressure vessel in order to mix a low-boiling-point blowing agent with a polyol. However, replacing an open tank that has been used in a conventional manufacturing facility with a pressure vessel is very cumbersome, and it is preferable to be able to use an open tank even when a low-boiling-point blowing agent is used. .

  In the polyol circulation path, a circulation pump is used to circulate a polyol composition in which a low-boiling-point foaming agent is mixed with a polyol. This circulation pump has a function of sucking liquid from the tank side (upstream side) and sending it out to the downstream side. Therefore, when the circulation pump performs a suction operation, the suction side (upstream side of the pump) is in a reduced pressure state, and once the low-boiling-point blowing agent mixed is gasified, it is foamed in the tank and becomes an increased state, resulting in a low boiling point. There is a problem that the foaming agent is scattered. This is because the vapor pressure of the conventional flon (HCFC-141b) is 0.065 MPa, whereas the vapor pressure of the new flon (HFC-245fa) is as high as 0.12 MPa. This is because there is a possibility of gasification. Such a phenomenon can occur not only when an open tank is used but also when a pressure tank is used.

Furthermore, as another problem, when the low boiling point blowing agent is fed in a state where it is pressurized to a predetermined value (0.2 MPa) or higher, the target low boiling point blowing agent itself may not correspond to the high pressure gas. , May be considered as a high-pressure gas production facility as a state. In order to mix the low boiling point blowing agent with the polyol, the low boiling point blowing agent is mixed in a liquefied state. Therefore, although it is not a high-pressure gas, the above-described problems may occur if the state is pressurized to a predetermined value or more.
JP-A-11-198132

  This invention is made | formed in view of the said situation, The subject can be used in any of an open tank and a pressure tank, and the low boiling-point foaming agent mixed with the polyol composition is not gasified. And a production facility for a polyol composition capable of preventing the low-boiling foaming agent from being pressurized to a predetermined value or more, and production capable of efficiently producing a polyol composition in a short time using the production facility Is to provide a method.

  In order to solve the above problems, a polyol composition production facility according to the present invention includes a tank for storing a polyol composition, a circulation path for returning the polyol composition delivered from the tank back to the tank, and this circulation. A first foaming agent for introducing a low-boiling-point foaming agent at a merging position set on the upstream side of the circulation pump and the circulation pump provided on the circulation path so that the polyol composition can circulate in the passage A pressure sensor provided on the upstream side of the charging path and the circulation pump and detects the pressure of the fluid flowing through the circulation path, and based on the detection result of the pressure sensor, the detected pressure becomes a predetermined value, A first pump control unit for controlling the motor speed of the circulation pump, and gradually mixing the low-boiling-point blowing agent while circulating the polyol composition in the circulation path. It is configured to go to.

  The operation and effect of the production equipment for the polyol composition having such a configuration is as follows. The polyol composition production facility of the present invention includes a tank in which the polyol composition is charged (when the fuel composition is initially charged, a low boiling point blowing agent is not mixed), and a circulation path for circulating the polyol composition. And a circulation pump provided on the circulation path. At the upstream side of the circulation pump, the first blowing agent charging path is joined, and at this joining position, the low boiling point blowing agent is mixed with the polyol composition flowing through the circulation path. This mixing is gradually performed, and the polyol composition mixed with the low boiling point blowing agent circulates in the circulation path.

  On the other hand, on the upstream side (suction side) of the circulation pump, a pressure sensor for detecting the pressure of the fluid flowing in the circulation path is provided, and the motor speed of the circulation pump is adjusted so that the detected pressure becomes a predetermined value. Is controlled. Therefore, the motor rotation speed is controlled so that the suction side of the circulation pump does not enter a reduced pressure state. As a result, since the gasification of the low boiling point foaming agent mixed in the polyol composition is prevented, both the open tank and the pressure tank can be used.

  Furthermore, a merging position is set on the upstream side of the circulation pump provided on the circulation path, and the low boiling point blowing agent is gradually added from here. That is, by introducing the low boiling point blowing agent from the suction side of the circulation pump, the low boiling point blowing agent can be mixed with the polyol without pressurizing to a predetermined value (0.2 MPa) or more. Therefore, the production facility is not treated as a high-pressure gas production facility, and a polyol composition can be produced even in a hazardous material production facility.

  As a preferred embodiment of the present invention, there is one in which a pressure regulating valve is provided in the circulation path so as not to be in a pressurized state of a predetermined value or more. By providing such a pressure control valve, it is possible to more reliably prevent the low-boiling foaming agent from being pressurized beyond a predetermined value.

  Another preferred embodiment of the present invention includes a mixer provided on the circulation path between the circulation pump and the joining position for stirring the polyol composition and the low boiling point blowing agent.

  By disposing the mixer at such a position, the low-boiling-point blowing agent immediately after charging can be stirred and mixed with the polyol composition. Moreover, the pressurization state with respect to a low boiling-point foaming agent can be relieve | moderated by pressurizing in the state which both mixed.

  Still another preferred embodiment of the present invention includes a configuration in which a first heat exchanger is provided in the middle of the first blowing agent charging path to cool the low boiling point blowing agent.

  By providing such a first heat exchanger, gasification of the low boiling point foaming agent can be reliably suppressed.

  As still another preferred embodiment of the present invention, a charging pump for feeding a low-boiling-point blowing agent through the first blowing agent charging path, and a first amount of polyol composition flowing in the circulation path are detected. Based on detection results of the flow rate sensor, the second flow rate sensor for detecting the amount of the low-boiling-point foaming agent charged at the merge position, and the rotation of the charging pump based on the detection results of the first flow rate sensor and the second flow rate sensor The thing provided with the 2nd pump control part which controls a number is mentioned.

  A predetermined amount (ratio) of a low boiling point foaming agent needs to be mixed in the polyol composition. According to the above configuration, the amount of the polyol composition flowing in the circulation path is detected by the first flow rate sensor, and the amount of the low-boiling-point blowing agent introduced at the joining position is detected by the second flow rate sensor. Based on the above, it is possible to control the motor speed of the charging pump for charging the low-boiling-point blowing agent. Thereby, an appropriate amount (ratio) of low boiling point foaming agents can be mixed.

  Yet another preferred embodiment of the present invention includes one in which the tank is an open tank.

  According to the polyol composition production facility of the present invention, it can be mixed with the polyol composition while suitably preventing gasification of the low-boiling foaming agent, and thus is particularly useful when using an open tank.

  Yet another preferred embodiment of the present invention includes a tank provided with a second blowing agent charging path for charging a low-boiling-point blowing agent into the tank.

  By providing a second blowing agent charging path for charging a low boiling foaming agent into the tank, a low boiling point foaming is applied to the polyol composition in combination with the first blowing agent charging path for charging the low boiling foaming agent in the circulation path. The agent can be charged efficiently. As a result, the mixing time can be shortened and productivity can be improved.

  Still another preferred embodiment of the present invention includes a configuration in which a second heat exchanger is provided in the middle of the second blowing agent charging path to cool the low boiling point blowing agent.

  By providing the second heat exchanger to cool the low boiling point blowing agent, gasification of the low boiling point blowing agent flowing through the second blowing agent charging path can be prevented. In addition, the amount of the low-boiling-point foaming agent introduced through the second foaming agent introduction path can be relatively increased, and the productivity can be further improved.

  As yet another preferred embodiment of the present invention, the second blowing agent charging path has a cylinder opening disposed in the tank, and a discharge hole through which a low-boiling-point blowing agent is discharged on the side and tip of the cylinder opening. Are formed.

  According to the above configuration, the low-boiling-point foaming agent is introduced into the tank through the discharge holes formed in the side surface and the tip of the tube port. Thereby, a low boiling point foaming agent is disperse | distributed suitably in a tank, and it can mix efficiently. Moreover, when the polyol composition in the tank is dispensed, the occurrence of residual liquid (contamination) in the second foaming agent charging path can be suppressed.

  In order to solve the above-mentioned problem, a method for producing a polyol composition according to the present invention is a method for producing a polyol composition using the above-described production equipment, wherein the merging is performed via the first blowing agent charging path. When the temperature of the polyol composition in the tank is at least lower than the boiling point of the low-boiling foaming agent while gradually introducing the low-boiling foaming agent at the position, the tank is passed through the second foaming agent charging passage. A low boiling foaming agent is added.

  According to the manufacturing method of the polyol composition concerning the present invention, the operation effect by the above-mentioned manufacturing equipment can be produced. That is, when mixing the low-boiling foaming agent into the polyol composition, the first foaming agent feeding path for gradually feeding the low-boiling foaming agent in the circulation path and the second foaming agent feeding for feeding the low-boiling foaming agent into the tank Efficiency can be improved by using the road together. Furthermore, when the low-boiling foaming agent is gradually added to the circulation path during the combined use and the temperature of the polyol composition in the tank is at least lower than the boiling point of the low-boiling foaming agent, the low-boiling foaming agent is added to the tank. It is possible to reliably prevent gasification of the low-boiling-point blowing agent that has been added.

  Furthermore, another method for producing a polyol composition of the present invention is a method for producing a polyol composition using the above-described production equipment, wherein the low-boiling-point blowing agent is formed at the merging position through the first blowing agent charging path. And gradually introducing the low-boiling-point foaming agent into the tank through the second foaming-agent introduction path, and when the low-boiling-point foaming agent has reached a predetermined amount, the second foaming The step of stopping the introduction of the low-boiling-point blowing agent via the agent charging path, and the low-boiling foaming agent is gradually added at the merging position via the first blowing agent charging path, thereby finely adjusting the mixing amount. And performing the process.

  According to the manufacturing method of the polyol composition concerning the present invention, the operation effect by the above-mentioned manufacturing equipment can be produced. That is, when mixing the low-boiling foaming agent into the polyol composition, the first foaming agent feeding path for gradually feeding the low-boiling foaming agent in the circulation path, and the second foaming agent feeding for feeding the low-boiling foaming agent into the tank Efficiency can be improved by using the road together. Further, in the combined use, when the amount of the low-boiling-point blowing agent charged reaches a predetermined amount, the introduction of the low-boiling-point blowing agent through the second blowing agent charging path is stopped, and then the first blowing agent charging path is opened. The low-boiling point blowing agent is gradually added at the merging position to finely adjust the mixing amount, so that the desired amount of the low-boiling point blowing agent can be introduced efficiently in a short time, and the precise mixing amount can be achieved through fine adjustment. Can be obtained.

  A preferred embodiment of a production facility for a polyol composition according to the present invention will be described with reference to the drawings. FIG. 1 is a flow diagram (schematic diagram) of equipment for producing a polyol composition. FIG. 2 is a perspective view showing an example of a tube opening.

<Configuration of manufacturing equipment>
The facility for producing a polyol composition according to the present invention is provided with an open tank 1 (hereinafter simply referred to as tank 1) for storing a polyol composition as a urethane stock solution. The polyol composition comprises a polyol compound, a foam stabilizer, a catalyst, and a foaming agent, and is used as a raw material for producing a urethane foam. When the polyol composition is first charged into the tank 1, the polyol composition excluding the foaming agent is charged from an opening provided in the upper part of the tank 1. As will be described later, the foaming agent is charged from another place and mixed.

  The tank 1 is provided with a stirring blade 1a for stirring the raw material in the tank, and the stirring blade 1a is rotationally driven by a driving device 1b. A cooling pipe 1 c is provided in the tank 1 to cool the polyol composition in the tank 1. The cylinder port 1d is disposed inside the tank 1 and constitutes a part of a second foaming agent charging path 30 described later. As shown in FIG. 2, the cylindrical port 1d has a plurality of discharge holes 1e formed on the side surface and a discharge hole 1f formed on the bottom surface. The shape or number of the discharge holes 1e and 1f is not limited to this.

  The polyol composition in the tank 1 is liquid and is configured to circulate along the circulation path 2. The circulation path 2 circulates counterclockwise in FIG. 1 starting from the bottom of the tank 1 and returns to the top of the tank 1. Further, as a path for charging the foaming agent, a first foaming agent charging path 3 (hereinafter abbreviated as first charging path 3) and a second foaming agent charging path 30 (hereinafter referred to as the second charging path 30). Are omitted). The first input path 3 joins the circulation path 2 at a merge position A provided in the middle of the circulation path 2. That is, the reason why the polyol composition is circulated is because the blowing agent is gradually added through the first charging path 3 in the middle of the circulating path. In this case, the foaming agent is introduced from the direction of arrow B.

  Next, each function provided in the middle of the circulation path 2 will be described. The circulation path 2 starting from the bottom of the tank 1 branches into a bifurcated way and merges into one immediately after that. A strainer 6 is provided at each of the two branches. The strainer 6 has a function of removing impurities. The circulation pump 8 is a suction pump and is provided for circulating the polyol composition in the circulation path 2. The merging position A, the mixer 26, and the pressure sensor 7 are arranged in order from the upstream side of the circulation pump 8. At the merge position A, the foaming agent is gradually introduced from the first introduction path 3. The mixer 26 has a function of stirring the polyol composition flowing through the circulation path 2 and the added blowing agent. A pressure sensor 7 is disposed on the downstream side of the mixer 26, and this pressure sensor 7 is provided for detecting the fluid pressure of the polyol composition flowing in the circulation path 2. Based on the pressure detection result by the pressure sensor 7, the motor 9 that drives the circulation pump 8 is controlled.

  A first flow sensor 10 is provided on the downstream side of the circulation pump 8. The first flow rate sensor 10 has a function of measuring the amount of the polyol composition flowing in the circulation path 2. The mixer 11 (non-drive mixer) has a function of sufficiently stirring the polyol composition flowing through the circulation path 2 and the blowing agent introduced at the joining position A. Two mixers 11 are provided in series along the circulation path 2. The number of mixers 11 can be set as appropriate.

  A heat exchanger 12 is provided on the downstream side of the mixer 11. The heat exchanger 12 has a function of cooling the polyol composition mixed with the blowing agent. The polyol composition that has passed through the heat exchanger 12 returns to the tank 1 through the circulation path 2. Further, a valve 4 and a valve 5 are provided on the downstream side of the heat exchanger 12, and when the polyol composition is circulated, the valve 4 is closed and the valve 5 is opened. There is a factory for manufacturing urethane foam downstream of the valve 4.

  Next, the configuration of the cooling pipe 1c will be briefly described. Cooling water is used as a fluid flowing through the cooling pipe 1c. The cooling water introduced from the direction of arrow C in FIG. 1 passes through a pipe divided into two branches. One is a cooling pipe 20 toward the tank 1, and the other is a cooling pipe 21 toward the heat exchanger 12. The cooling water that has passed through the tank 1 returns to the direction of arrow D through the return pipe 18. The cooling water that has passed through the heat exchanger 12 also returns to the direction of arrow D through the return pipe 19.

Next, the introduction path of the foaming agent will be described. The foaming agent introduced from the direction of arrow E in FIG. 1 passes through a pipe divided into two branches. One is a first input path 3 indicated by an arrow B, and the other is a second input path 30 indicated by an arrow F. As an example of the foaming agent, a CFC substitute _{HFC-245fa (CF 3 CH 2} CHF 2:. Corresponding to the low-boiling blowing agent) including without limited thereto.

  A valve 13 is provided on the upstream side of the first charging path 3, and the valve 13 is opened when charging the foaming agent. A strainer 14 is provided on the downstream side of the valve 13 and functions as a filter for removing impurities. A dosing pump 15 is provided on the downstream side of the strainer 14 so that a foaming agent can be fed. The input pump 15 is driven by a motor 16. A second flow rate sensor 17 is provided on the downstream side of the input pump 15. The second flow rate sensor 17 has a function of detecting the amount of foaming agent flowing through the charging path 3, that is, the amount of foaming agent charged from the merging position A.

  A safety valve 27 is provided in the first charging path 3 on the downstream side of the charging pump 15 so that the fluid pressure of the circulating blowing agent does not exceed a predetermined value. The predetermined value is set to 0.2 MPa, and when the pressure exceeds this value, the safety valve is operated to release the pressure to the pump suction side. As a result, the foaming agent is not pressurized to 0.2 MPa or more. This is because when the foaming agent is pressurized to 0.2 MPa or more, even if the foaming agent is not a high-pressure gas, this facility may be regarded as a high-pressure gas production facility.

  As described above, the merge position A is provided on the suction side (upstream side) of the circulation pump 8. By providing the merging position A on the decompression side in this way, it is not necessary to pressurize the foaming agent when the foaming agent is added, and in this respect as well, pressurization to the foaming agent can be suppressed. If the merging position A is provided on the delivery side (downstream side) of the circulation pump 8, it is necessary to pressurize considerably in order to introduce the foaming agent, and the predetermined value may be exceeded.

  A heat exchanger 28 (corresponding to the first heat exchanger) is provided on the upstream side of the valve 13. The heat exchanger 28 is provided with a pipe 29 for circulating the cooling medium, and has a function of cooling the foaming agent delivered through the first charging path 3. Thereby, gasification of a foaming agent can be prevented reliably. Any appropriate cooling medium can be used.

  Next, the second charging path 30 will be described. The second charging path 30 includes a cylindrical port 1 d on the downstream side, and the cylindrical port 1 d is disposed in the tank 1. A valve 34 is provided on the upstream side of the cylinder port 1d, and the valve 34 is opened when the foaming agent is charged through the second charging passage 30. A heat exchanger 31 (corresponding to the second heat exchanger) is provided on the upstream side of the second charging path 30. The heat exchanger 31 is provided with a pipe 32 for circulating the cooling medium, and has a function of cooling the foaming agent delivered through the second input path 30. The third flow rate sensor 33 has a function of detecting the amount of foaming agent flowing through the second charging path 30, that is, the amount of foaming agent charged into the tank 1.

  The foaming agent mixed in the polyol composition in this embodiment is HFC-245fa as described above, and has a boiling point of 15.3 ° C., which is lower than that of conventional Freon. Further, the vapor pressure is 0.12 MPa, which is higher than that of conventional chlorofluorocarbons. Therefore, it is necessary to prevent the foaming agent from being gasified, which is particularly important because the open tank 1 is used in this embodiment. Therefore, when the foaming agent is introduced into the circulation path 2 via the first introduction path 3, the liquid foaming agent is introduced into the circulation path 2 in a state where the pressure and temperature are set within a predetermined range. Further, while the polyol composition mixed with the foaming agent is circulating in the circulation path 2, the pressure and temperature are within a predetermined range so that the foaming agent is not gasified. That is, the polyol composition mixed with the foaming agent is cooled by the heat exchanger 12 provided in the circulation path 2, and further, the foaming agent is cooled and gasified by the heat exchanger 28 provided in the first charging path 3. Is preventing.

  In addition, the mixing time can be shortened by supplying the foaming agent to the tank 1 through the second charging path 30. However, it is necessary to prevent the foaming agent from being gasified even during the charging. Therefore, the polyol composition in the tank 1 is cooled within the predetermined range by cooling the polyol composition circulating in the circulation path 2 by the heat exchanger 12 while cooling the polyol composition in the tank 1 with the cooling pipe 1c. Temperature. Further, the foaming agent is cooled by the heat exchanger 31 provided in the second charging path 30 to prevent gasification.

  Various functions (for example, a temperature sensor) other than those shown in FIG. 1 are added to the circulation path 2, the first input path 3, and the second input path 30, but the description is simplified. Omitted for that.

<Configuration of control unit>
Next, the structure of the control part of the manufacturing equipment of a polyol composition is demonstrated. The first control unit 22 (corresponding to the first pump control unit) rotates the motor 9 that drives the circulation pump 8 based on the detection result of the pressure sensor 7 so that the pressure value becomes a predetermined value set in advance. Control the number. The reason for performing this control will be described.

  The polyol composition charged into the tank 1 circulates in the circulation path 2 and is mixed with a foaming agent charged in small amounts at the joining position A. In the circulation path 2, gasification of the foaming agent is prevented by cooling the polyol composition mixed with the foaming agent by the heat exchanger 12. By the way, the circulation pump 8 has a function of sucking the upstream fluid and sending it out to the downstream side. This suction action acts in a direction in which the upstream side (suction side) of the circulation pump 8 is depressurized. In such a reduced pressure state, the foaming agent may gasify due to the high vapor pressure of the foaming agent. When the foaming agent is gasified, the mixing efficiency decreases, for example, the mixed foaming agent escapes to the atmosphere. Therefore, it is necessary to prevent gasification due to this reduced pressure. Therefore, in the present invention, the pressure on the suction side of the circulation pump 8 is detected by the pressure sensor 7, and when the pressure is reduced, the motor 9 is controlled so as to reduce the rotation speed in order to maintain the pressure. Thereby, the decompression on the suction side can be prevented, and the foaming agent can be prevented from being inadvertently gasified.

  Next, the function of the second control unit 23 (corresponding to the second pump control unit) will be described. The second control unit 23 controls the rotation speed of the motor 16 that drives the charging pump 15 based on the flow rate data from the first flow rate sensor 10 and the second flow rate sensor 17. That is, since it is necessary to feed the foaming agent at a constant flow rate ratio relative to the polyol composition, the flow rate of the circulation path 2 and the flow rate of the charging path 3 are detected, and the foaming agent is charged so that the ratio is constant. The amount is controlled. Thereby, a foaming agent can be thrown in in the circulation path 2 with a suitable ratio.

  The third control unit 24 controls charging of the foaming agent in the first charging path 3 based on the measurement result of the weight of the polyol composition in the tank 1. For this reason, a tank meter 25 for detecting the weight of the polyol composition is provided. As the blowing agent is gradually added, the weight of the tank 1 gradually increases. When this weight reaches the set weight, the rotation of the motor 16 is stopped and the mixing operation of the foaming agent is stopped.

  The fourth control unit 35 controls charging of the foaming agent in the second charging path 30 based on the measurement result of the temperature of the polyol composition in the tank 1. Therefore, a temperature sensor 36 (for example, a bimetal thermometer) that detects the temperature of the polyol composition is installed at the bottom of the tank 1. Thereby, when the polyol composition in the tank 1 reaches a temperature within a predetermined range, the valve 34 can be opened and the foaming agent can be put into the tank 1.

  Further, the fourth control unit 35 controls the injection of the foaming agent in the second input path 30 based on the measurement result of the weight of the polyol composition in the tank 1. That is, the tank meter 25 detects the weight of the tank 1 that is increased by the introduction of the foaming agent, and when the weight reaches the set weight, the valve 34 is closed and the introduction of the foaming agent is stopped. In order to obtain an accurate mixing amount, the set value of the weight of the tank 1 when stopping the introduction of the foaming agent in the second charging path 30 is the tank value when stopping the charging of the foaming agent in the first charging path 3. A value smaller than the set value of the weight of 1 is set.

<Manufacture of polyol composition>
Next, the procedure in the case of manufacturing a polyol composition with the polyol composition manufacturing equipment of FIG. 1 will be described. First, the polyol composition excluding the foaming agent is put into the tank 1. After the charging, the circulation pump 8 is driven to circulate the polyol composition in the circulation path 2. On the other hand, the foaming agent is introduced little by little from the first introduction path 3. Thereby, a foaming agent is mixed gradually and the polyol composition with which the foaming agent was mixed circulates through the circulation path 2. During this circulation operation, the motor control of the circulation pump 8 is performed by the first control unit 22, and gasification of the foaming agent due to decompression is prevented. Further, the second control unit 23 controls the motor of the circulation pump 15 so that the foaming agent is charged at a predetermined ratio.

  The polyol composition in the tank 1 is cooled by the cooling pipe 1c, and the polyol composition returning to the tank 1 from the circulation path 2 is cooled by the heat exchanger 12, so that the polyol composition in the tank 1 is The object has a predetermined range of temperatures. At this time, the fourth control unit 35 is controlled so that the foaming agent is introduced into the tank 1 when the temperature of the polyol composition in the tank 1 is at least lower than the boiling point of the foaming agent. preferable. Thereby, gasification of a foaming agent can be prevented reliably.

  The foaming agent charged into the tank 1 through the second charging path 30 is discharged from the discharge holes 1e and 1f formed in the cylinder port 1d. In the present embodiment, by providing a plurality of discharge holes 1 e, the foaming agent is discharged in a shower shape and is effectively dispersed in the tank 1. Moreover, since there is much injection | pouring amount compared with the 1st injection | throwing-in path 3, a foaming agent can be injected | thrown-in efficiently in a short time.

  The blowing agent is introduced directly into the tank 1 from the second introduction path 30 while being gradually introduced into the circulation path 2 from the first introduction path 3. Then, when the tank meter 25 detects that the mixing amount of the foaming agent has reached a predetermined amount, the fourth control unit 35 stops the introduction of the foaming agent from the second charging path 30. This predetermined amount is set smaller than the mixing amount of the target foaming agent. After the introduction of the foaming agent in the second introduction path 30 is stopped, the foaming agent is introduced little by little from the first introduction path 3 and fine adjustment is performed so that the target mixing amount is obtained. When the tank meter 25 detects that the mixing amount of the foaming agent has reached the target amount, the third control unit 24 stops charging the foaming agent from the first charging path 30.

  That is, according to the method for producing a polyol composition of the present invention, first, the blowing agent is gradually charged through the first charging path 3. Next, when the condition for allowing the foaming agent to be directly charged into the tank 1 is satisfied, the foaming agent is charged through the second charging path 30. Then, immediately before the target mixing amount, the charging through the second charging path 30 is stopped. Finally, by performing fine adjustment through the first charging path 3, it is possible to efficiently and accurately charge the foaming agent.

  When mixing of the foaming agent is completed, the valve 5 of the circulation path 2 is closed and the valve 4 is opened, and the polyol composition is sent to the factory. On the factory side, the polyurethane foam foam is produced by stirring the polyol composition and the polyisocyanate component.

<Another embodiment>
(1) In the above-described embodiment, an example using an open tank has been shown. However, in the present invention, a pressure tank may be used instead of the open tank. In addition, the polyol composition is initially charged from the upper part of the open tank, but it is preferable to cover the polyol composition after the charging. Even when the tank is covered, the internal pressure is equivalent to atmospheric pressure. In addition, the method of throwing a polyol composition into a tank can be performed by an appropriate method.

  (2) In the above-described embodiment, the example in which the foaming agent can be charged in a short time using the second charging path 30 has been shown, but the present invention is not limited to this. Further, the switching of the foaming agent charging in the second charging path 30 may be based on the detection result of the third flow sensor 33 instead of the tank meter 25. The switching of the foaming agent may be switched manually by an operator, or a pump may be provided in the second charging path 30 to control its motor drive.

Flow chart of production equipment for polyol composition A perspective view showing an example of a tube opening

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Open tank 2 Circulation path 3 1st foaming agent input path 7 Pressure sensor 8 Circulation pump 9 Motor 10 1st flow sensor 15 Input pump 16 Motor 17 2nd flow sensor 22 1st control part 23 2nd control part 24 3rd control Part 26 mixer 27 safety valve 28 heat exchanger 30 second blowing agent charging path 31 heat exchanger 35 fourth control part 36 temperature sensor A merge position

Claims (10)

A tank for storing the polyol composition;
A circulation path for returning the polyol composition delivered from the tank back to the tank;
A circulation pump provided on the circulation path so that the polyol composition can circulate in the circulation path;
A first blowing agent introduction path for introducing a low boiling point blowing agent at a confluence position set on the upstream side of the circulation pump;
A pressure sensor provided on the upstream side of the circulation pump for detecting the pressure of fluid flowing through the circulation path;
A first pump controller that controls the number of rotations of the motor of the circulation pump so that the detected pressure becomes a predetermined value based on the detection result of the pressure sensor;
A facility for producing a polyol composition, wherein the low boiling point blowing agent is gradually mixed while circulating the polyol composition in the circulation path. The equipment for producing a polyol composition according to claim 1, wherein a mixer for stirring the polyol composition and the low-boiling-point blowing agent is provided on the circulation path between the circulation pump and the joining position. The polyol composition manufacturing facility according to claim 1 or 2, wherein a first heat exchanger is provided in the middle of the first blowing agent charging path to cool the low boiling point blowing agent. A charging pump for feeding a low boiling point blowing agent through the first blowing agent charging channel;
A first flow sensor for detecting an amount of a polyol composition flowing in the circulation path;
A second flow rate sensor for detecting the amount of the low boiling point blowing agent charged into the merging position;
4. The apparatus according to claim 1, further comprising: a second pump control unit that controls a motor rotation speed of the input pump based on detection results of the first flow sensor and the second flow sensor. 5. Equipment for producing polyol compositions. The said tank is an open tank, The manufacturing apparatus of the polyol composition of any one of Claims 1-4. The equipment for producing a polyol composition according to any one of claims 1 to 5, further comprising a second blowing agent charging path for charging a low-boiling-point blowing agent into the tank. The equipment for producing a polyol composition according to claim 6, wherein a second heat exchanger is provided in the middle of the second blowing agent charging path to cool the low boiling point blowing agent. The said 2nd foaming agent injection | throwing-in path | route is provided with the cylinder opening arrange | positioned in the said tank, The discharge hole in which a low boiling-point blowing agent is discharged is formed in the side surface and front-end | tip of the cylinder opening. Equipment for producing polyol compositions. A method for producing a polyol composition using the production facility according to any one of claims 6 to 8,
When the temperature of the polyol composition in the tank is at least less than the boiling point of the low-boiling-point blowing agent while gradually feeding the low-boiling-point blowing agent at the joining position through the first blowing agent charging path, A method for producing a polyol composition, wherein a low-boiling-point foaming agent is introduced into the tank through a second foaming agent introduction path. A method for producing a polyol composition using the production facility according to any one of claims 6 to 8,
Introducing a low-boiling-point blowing agent into the tank via the second blowing agent charging path while gradually charging a low-boiling-point blowing agent at the joining position via the first blowing agent charging path;
A step of stopping the introduction of the low-boiling-point blowing agent via the second blowing agent-feeding path when the low-boiling-point blowing agent charged reaches a predetermined amount;
And a step of finely adjusting the mixing amount by gradually introducing a low-boiling-point blowing agent at the joining position through the first foaming agent charging path, and a method for producing a polyol composition.

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