JP5628538B2 - Polyurethane foam manufacturing apparatus and polyurethane foam manufacturing method - Google Patents

Description

  The present invention relates to a polyurethane foam manufacturing apparatus and a polyurethane foam manufacturing method. The present invention particularly relates to a polyurethane foam production apparatus and a polyurethane foam production method suitable for foaming polyurethane foam performed using liquid (supercritical, subcritical, or liquid) carbon dioxide as a foaming agent.

  Conventionally, polyurethane foam has been widely used as a heat insulating board, a heat insulating material by spraying, a filling agent, and the like. This polyurethane foam usually uses a raw material liquid containing a polyisocyanate component, an active hydrogen group-containing compound component, and a foaming agent. It is manufactured by discharging and reacting and solidifying while foaming the discharged foam limit amount. Until now, Freon etc. have been used for this foaming agent.

  However, in recent years, many foaming agents such as Freon are being regulated as foaming agents for polyurethane foam due to problems such as ozone layer destruction, and methods using carbon dioxide as the foaming agent are being studied. When carbon dioxide is used as a blowing agent, it is necessary to use liquefied carbon dioxide and supply a predetermined amount thereof. The critical point of carbon dioxide is about 31 ° C. and about 7 MPa, and it is a gas at room temperature. It is easy to become. For this reason, when a fixed amount of carbon dioxide is to be pumped from a carbon dioxide storage container such as a cylinder, gas carbon dioxide tends to be mixed, and there is a problem that a predetermined amount of liquid carbon dioxide cannot be pumped. In particular, since the pressure tends to decrease on the suction side of the pump, there is a problem that carbon dioxide that has become a gas is likely to be mixed in, and it becomes impossible to pump a fixed amount of liquid carbon dioxide.

  For this reason, various ideas for supplying a fixed amount of liquid carbon dioxide without vaporization have been proposed.

  For example, in Patent Document 1, a pressurized gas container is provided, and pressurized gas is supplied from the pressurized gas container to the liquefied carbon dioxide container and pressurized to hold the liquefied carbon dioxide as a liquid. Patent Document 2 discloses a technique for keeping the temperature of liquefied carbon dioxide low and preventing vaporization of liquefied carbon dioxide introduced into the first liquefied carbon dioxide metering pump and the second liquefied carbon dioxide metering pump. ing. Patent Document 3 discloses that a chiller that adjusts the temperature of the refrigerant includes a refrigerant and a heat transfer tube that cools the refrigerant, and a liquefied carbon dioxide transfer channel is provided in the chiller. .

  However, all of the urethane foam manufacturing apparatuses disclosed in Patent Documents 1 to 3 measure and supply the supply amount of carbon dioxide using a carbon dioxide metering pump, and supply liquid carbon dioxide. This pump is essential. That is, the problem of vaporization of liquefied carbon dioxide is caused by the use of a pump for measuring carbon dioxide. As long as the pump is used, the problem of vaporization of liquefied carbon dioxide occurs. Therefore, in order to solve the problem as much as possible, heat exchangers such as chillers and distribution pipes are insulated to keep the temperature of liquefied carbon dioxide low, or the pressure is increased using a pressurized gas container to vaporize. It is something to prevent.

  However, even if the liquefied state can be maintained in the vicinity of the liquefied carbon dioxide container, as long as the pump is used for measuring carbon dioxide, the pressure tends to decrease during the suction process on the suction side of the pump, and the carbon dioxide tends to vaporize. It is not a drastic solution to the problem. In addition, the number of members such as a pressurized container and a heat exchanger increases, and the apparatus becomes large and complicated.

  Therefore, the present inventors have solved the problem of metering an appropriate amount of carbon dioxide with a pump, and a polyurethane foam manufacturing apparatus capable of solving the problem of carbon dioxide vaporization caused by the use of the pump in carbon dioxide metering. The proposal which provides a polyurethane foam manufacturing method was performed (refer patent document 4).

JP 2006-192720 A Japanese Patent Laid-Open No. 2005-200484 JP 2006-29895 A JP 2009-7525 A

  As described above, in the method not using a pump for measuring carbon dioxide proposed by the present inventors (Patent Document 4), the first pressure of liquefied carbon dioxide in the liquefied carbon dioxide container and the discharge pressure (second pressure). ) To transport liquefied carbon dioxide from the primary pipe to the secondary pipe.

  On the other hand, the 1st pressure of the liquefied carbon dioxide in a liquefied carbon dioxide container changes greatly with temperature. FIG. 8 is a graph showing a temperature-pressure relationship depending on a difference in filling amount of the liquefied carbon dioxide container. As shown in FIG. 8, the pressure in the liquefied carbon dioxide container is higher than the discharge pressure (4 MPa to 7 MPa) without heating the liquefied carbon dioxide container in the summer when the temperature is 30 ° C. or higher. On the other hand, in the winter when the temperature is lower than 5 ° C., the pressure in the liquefied carbon dioxide container becomes a low pressure equal to or lower than the discharge pressure. Therefore, in order to manage the 1st pressure in a liquefied carbon dioxide container on the same conditions throughout the year, a liquefied carbon dioxide container may be heated and used, for example to 40 ° C. In such a case, the first pressure in the liquefied carbon dioxide container is greatly influenced not only by the temperature but also by the amount of liquefied carbon dioxide filled in the container. In the case of FIG. 8, when the filling amount is 30 kg (1), it reaches 13.2 MPa at 40 ° C., whereas in the case of the filling amount 20.1 kg (4), 9 MPa at 40 ° C. Become.

  In the above case, when the discharge pressure (second pressure) is set to 7 MPa, for example, when the filling amount in the liquefied carbon dioxide container is 20.1 kg (4), the pressure difference between the first pressure and the discharge pressure is about In the case of 2 MPa and a filling amount of 30 kg in the liquefied carbon dioxide container (1), the pressure difference between the first pressure and the discharge pressure is about 6.2 MPa. When pressure control is performed with the needle valve throttle between the primary pipe and the secondary pipe being constant, the first pressure and the second pressure are obtained when the filling amount is 20.1 kg and the filling amount is 30 kg. The flow rate of liquefied carbon dioxide flowing through the secondary pipe is greatly different due to the pressure difference between the two. In the production of polyurethane foam, water as a blowing agent is usually used together with liquefied carbon dioxide. However, when the flow rate of liquefied carbon dioxide is increased, excessive foaming is caused by water and liquefied carbon dioxide, and a normal polyurethane foam is obtained. If the flow rate of liquefied carbon dioxide is too small, foaming with water alone cannot provide the desired foaming ratio, and the amount of raw materials used is greatly increased. It was found to occur.

  In the present invention, when the first pressure in the liquefied carbon dioxide container is managed under the same conditions throughout the year, for example, when the liquefied carbon dioxide container is maintained at 40 ° C., the filling amount of the liquefied carbon dioxide container is reduced. Regardless, an object of the present invention is to provide a polyurethane foam manufacturing apparatus and a polyurethane foam manufacturing method capable of keeping the flow rate of liquefied carbon dioxide flowing through the secondary pipe constant.

  In order to solve the above technical problem, the present invention provides a polyurethane foam manufacturing apparatus and a polyurethane foam manufacturing method having the following configuration.

The polyurethane foam manufacturing apparatus according to the first aspect of the present invention includes a liquid A mainly composed of polyisocyanate, a liquid B mainly composed of a polyol, and liquefied carbon dioxide as a blowing agent supplied from a liquefied carbon dioxide container. Are mixed with the liquid A and / or liquid B fed through the supply pipes, the liquid A and the liquid B are mixed, and a predetermined discharge is performed. A polyurethane foam manufacturing apparatus equipped with a discharge device for discharging with pressure,
A primary pipe having a first end connected to the liquefied carbon dioxide container having a first pressure higher than the discharge pressure in the container and transporting the liquefied carbon dioxide from the liquefied carbon dioxide container while maintaining the first pressure. When,
The terminal side is connected to the supply pipe of at least one of the A liquid and the B liquid, and the liquefied carbon dioxide is supplied to the supply pipe of at least one of the A liquid and the B liquid at a second pressure lower than the first pressure. Secondary piping to feed,
A start end side is connected to a terminal end side of the primary pipe, a terminal end side is connected to a start end side of the secondary pipe, and the third pressure is a low pressure equal to or lower than the first pressure and a high pressure equal to or higher than the second pressure. And a tertiary pipe for conveying liquefied carbon dioxide from the primary pipe to the secondary pipe;
The third pipe is connected between the terminal end side of the primary pipe and the start end side of the third pipe, and the flow rate of liquefied carbon dioxide from the primary pipe to the third pipe is adjusted, and the third pipe is adjusted. Pressure control means for controlling the inside of the next pipe to exhibit the third pressure;
It is connected between the terminal end side of the tertiary piping and the starting end side of the secondary piping, and flows through the secondary piping so that the flow rate in the secondary piping exhibits the second pressure. A flow rate adjusting means for adjusting the flow rate of the liquefied carbon dioxide,
It is characterized by providing.

The pressure control means includes
An on-off valve that can be switched between opening and closing;
A third pressure gauge for measuring the pressure in the tertiary pipe;
When the pressure measured by the third pressure gauge exceeds the upper limit of a predetermined range including the third pressure, the on-off valve is closed, and the pressure measured by the third pressure gauge is within a predetermined range including the third pressure. Valve control means for opening the on-off valve when the upper limit is not exceeded,
May be provided.

  Further, the pressure control means may include an on-off valve constituted by a regulating valve composed of a linear motion type closing part.

  The pressure control means may include a throttle valve capable of adjusting the flow rate of liquefied carbon dioxide from the primary pipe to the tertiary pipe.

  The throttle valve of the pressure control means may be a needle valve whose throttle degree is controlled by the valve control means of the pressure control means.

Furthermore, the flow rate adjusting means includes
An on-off valve that can be switched between opening and closing;
When the discharge A liquid and B liquid are not discharged from the discharge device, the open / close valve is closed, and the open / close valve is controlled to open in conjunction with the operation of supplying the A liquid and B liquid into the discharge device. Valve control means may be provided.

  Further, the flow rate adjusting means may include a throttle valve capable of adjusting a flow rate of liquefied carbon dioxide from the tertiary pipe to the secondary pipe. Further, the throttle valve may be constituted by a needle valve whose throttle degree is controlled by the valve control means.

Further, the on-off valve of the flow rate adjusting means includes a throttle mechanism capable of adjusting the flow rate,
The valve control means may be configured to control the throttle amount of the on-off valve so that the second pipe has a flow rate that exhibits the second pressure.

  Furthermore, a supply pump for supplying the A liquid and the B liquid to the discharge device is provided, and the valve control means of the flow rate adjusting means controls the on-off valve in conjunction with the operation of the supply pump. It may be configured.

  Furthermore, you may provide the pressurization means which pressurizes the inside of the said liquefied carbon dioxide container to the 1st pressure higher pressure than the said discharge pressure. As the pressurizing means, specifically, a heating machine for heating the liquefied carbon dioxide container can be used. That is, for example, when the outside air temperature in winter is low, it may be difficult to maintain the inside of the liquefied carbon dioxide container at the first pressure, so that the inside of the container is set to the first pressure by using the pressurizing means. be able to.

  Further, a blow valve for filling the liquefied carbon dioxide from the primary pipe into the tertiary pipe may be provided.

  Furthermore, the first pressure may be in the range of 5 MPa to 14 MPa, the third pressure may be in the range of 5 MPa to 10 MPa, and the second pressure and the discharge pressure may be in the range of 4 MPa to 7 MPa. .

  The discharge device may include a heater that heats the liquid A and the liquid B after the liquefied carbon dioxide is mixed with at least one of the liquid A and the liquid B.

The method for producing a polyurethane foam according to the second aspect of the present invention includes a liquid A mainly composed of polyisocyanate, a liquid B mainly composed of a polyol, and liquefied dioxide as a blowing agent supplied from a liquefied carbon dioxide container. When producing polyurethane foam by mixing with carbon, the primary pipe, the third pipe, the second pipe from the liquefied carbon dioxide container through the primary pipe, the tertiary pipe, and the secondary pipe. A discharge device is provided that conveys the liquefied carbon dioxide by each pressure difference of the next piping, mixes the liquefied carbon dioxide with the liquid A and / or liquid B, stores the liquid inside, and discharges the liquid carbon dioxide at a predetermined discharge pressure. A method for producing a polyurethane foam using a polyurethane foam production apparatus comprising:
While maintaining the first pressure through the liquefied carbon dioxide in the liquefied carbon dioxide container having a first pressure higher than the discharge pressure inside, and in the primary pipe connected to the liquefied carbon dioxide container at the start end side. Transport,
The on-off valve between the primary pipe and the tertiary pipe is controlled to open and close, the pressure in the tertiary pipe is controlled to a third pressure lower than the first pressure, and the third In the next pipe, the liquefied carbon dioxide is conveyed at the third pressure,
The flow rate of liquefied carbon dioxide sent out from the tertiary pipe is adjusted and supplied into the secondary pipe, and the liquefied carbon dioxide is passed through the secondary pipe at a second pressure lower than the third pressure. Transport the
Supplying the liquefied carbon dioxide conveyed in the secondary pipe to the supply pipe of the liquid A and / or liquid B in the state of the second pressure;
In a state where the liquefied carbon dioxide and the A liquid and / or B liquid are mixed, the A liquid and the B liquid are mixed and discharged in the discharge device, and the liquefied carbon dioxide is vaporized to foam polyurethane foam. A method for producing a polyurethane foam is provided.

  The method may further include the step of pressurizing the liquefied carbon dioxide container to the first pressure by heating the liquefied carbon dioxide container.

  In general, carbon dioxide in a supercritical state is not a liquid, but in the present invention, liquefied carbon dioxide includes carbon dioxide in a supercritical state, a subcritical state, and a liquid state. Subcritical carbon dioxide is liquid carbon dioxide whose pressure is higher than the critical pressure of carbon dioxide and whose temperature is lower than the critical temperature, or whose pressure is lower than the critical pressure of carbon dioxide and whose temperature is critical. Carbon dioxide in a liquid state at a temperature or higher and a state in which both the temperature and pressure are less than the critical point but close to this, specifically, carbon dioxide having a temperature of 20 ° C. or higher and a pressure of 5 MPa or higher. .

  According to the polyurethane foam manufacturing apparatus of the present invention, the tertiary pipe is provided between the primary pipe and the secondary pipe, and the terminal side of the primary pipe and the start side of the tertiary pipe are provided. And the flow rate of liquefied carbon dioxide from the primary pipe to the tertiary pipe is adjusted, and the inside of the tertiary pipe is a low pressure equal to or lower than the first pressure and a high pressure equal to or higher than the second pressure. Pressure control means for controlling to exhibit the third pressure. Thus, the tertiary pipe can function as a pressure buffer of the first pressure that changes depending on the filling amount of the liquefied carbon dioxide container, and the second pipe has a low pressure equal to or lower than the first pressure. The pressure can be controlled to a third pressure that is higher than the pressure. Therefore, the flow rate of liquefied carbon dioxide flowing through the secondary pipe can be kept constant regardless of the filling amount of the liquefied carbon dioxide container. Therefore, the amount of water as a blowing agent added to the liquefied carbon dioxide and the B liquid side is stabilized, a balanced foaming state and foaming ratio can be exhibited, and a polyurethane foam can be stably obtained. .

It is a figure which shows typically the structure of the polyurethane foam manufacturing apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows typically the other structure of the polyurethane foam manufacturing apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows typically other structures of the polyurethane foam manufacturing apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of a liquefied carbon dioxide container. It is a phase diagram of carbon dioxide. It is a flowchart of the pressure control method by tertiary piping. It is a flowchart which shows the manufacturing process of the polyurethane foam using the polyurethane foam manufacturing apparatus of FIG. It is a graph which shows the temperature-pressure relationship by the difference in the filling amount of a liquefied carbon dioxide container.

  Hereinafter, a polyurethane foam manufacturing apparatus according to an embodiment of the present invention will be described with reference to the accompanying drawings.

Embodiment 1
<Polyurethane foam production equipment>
FIG. 1 is a diagram schematically showing a configuration of a polyurethane foam manufacturing apparatus 1 according to Embodiment 1 of the present invention. The polyurethane foam manufacturing apparatus 1 according to Embodiment 1 shown in FIG. 1 shows a case where liquefied carbon dioxide is supplied to a polyol component. In this polyurethane foam manufacturing apparatus 1, a component liquid obtained by mixing liquefied carbon dioxide 100 (see FIG. 4) stored in a liquefied carbon dioxide container 20 and an isocyanate component are used using a warmer 3 and a hose heater 4. Transport while heating, mix in spray gun 5 and discharge. In addition, the warmer 3 is comprised by two warmers 3a and 3b as shown in another example of FIG. 2, and may be comprised so that each liquid may be heated independently. Moreover, the hose heater 4 is comprised by two hose heaters 4a and 4b as shown in another example of FIG. 3, and you may be comprised so that each liquid may be heated independently.

  As shown in FIG. 1, this polyurethane foam manufacturing apparatus 1 includes a liquefied carbon dioxide container 20, a polyol component storage container 30 for storing a B liquid mainly composed of polyol, and an A liquid mainly composed of polyisocyanate. And a polyisocyanate component storage container 40 to be stored. In addition, the polyurethane foam manufacturing apparatus 1 includes a primary pipe L11, a tertiary pipe L15, and a secondary pipe L12 that convey liquefied carbon dioxide (the upstream side of the check valve 29 is L12a and the downstream side as described later. L liquid pipe L13 which conveys B liquid, and A liquid pipe L14 which conveys A liquid communicate with the discharge device 2.

  In this polyurethane foam manufacturing apparatus 1, the primary pipe L11 that conveys liquefied carbon dioxide at the first pressure in the liquefied carbon dioxide container and the terminal side are connected to the A liquid or the B liquid, and at a second pressure that is equal to or higher than the discharge pressure. A tertiary pipe L15 is provided between the secondary pipe L12 for transporting liquefied carbon dioxide. This third pipe L15 absorbs the fluctuation of the first pressure for each liquefied carbon dioxide container that changes depending on the filling amount of liquefied carbon dioxide for each liquefied carbon dioxide container 20 by the pressure control mechanism 45 described later. It can function as a pressure buffer. For this reason, regardless of the amount of liquefied carbon dioxide in the liquefied carbon dioxide container 20, the flow rate of liquefied carbon dioxide flowing in the secondary pipe L12 can be kept constant.

  The starting end of the primary pipe L11 that conveys liquefied carbon dioxide is connected to the connector 22 of the liquefied carbon dioxide container 20. A first pressure gauge 25 that measures the pressure in the filter 23 and the primary pipe L11 is provided in the middle of the primary pipe L11. In addition, an on-off valve 46 is provided at the boundary between the primary pipe L11 and the tertiary pipe L15, and the third pipe is connected to the third pipe L11 through a pressure control mechanism 45 including the on-off valve 46 and the needle valve 47. Connected to piping. The third pipe L15 is provided with a third pressure gauge 48 for measuring the pressure in the blow valve 24 and the third pipe L15. The blow valve 24 may be provided on the primary piping side, but the third piping side is preferable in consideration of liquid filling properties. In addition, an opening / closing valve 26 is provided at the boundary between the tertiary piping L15 and the secondary piping L12, and is connected to the secondary piping L15 via a flow rate adjusting mechanism 15 constituted by the opening / closing valve 26 and the needle valve 27. ing. The secondary pipe L12 is provided with a second pressure gauge 28 and a check valve 29 for measuring the pressure in the secondary pipe L12, and is connected to the mixer 32 provided in the B liquid pipe L13. Has been.

  The B liquid pipe L <b> 13 includes a B liquid pump 31 and a mixer 32, and communicates with the spray gun 5 of the discharge device 2. The A liquid pipe L <b> 14 includes the A liquid pump 41 and communicates with the spray gun 5 of the discharge device 2. The spray gun 5 mixes the A liquid fed by the A liquid pipe L14 and the B liquid pipe L13 and the B liquid mixed with the liquefied carbon dioxide, and discharges them from the discharge port. The A liquid pipe L14 and the B liquid pipe L13 are provided with a heater 3 and a hose heater 4, and the reaction conditions are stabilized by heating the supplied liquid to keep the temperature constant. In addition, the reactivity at the time of discharge from the spray gun 5 can be enhanced.

  In the example of FIG. 1, the liquefied carbon dioxide is configured to be mixed with the B liquid, but may be configured to be mixed with the A liquid as shown in FIG. In this case, the mixer 42 is provided in the A liquid pipe L14. Moreover, as shown in FIG. 3, you may be comprised so that it may mix with both A liquid and B liquid. In this case, the secondary pipe L12 may be branched and connected to the mixer 42 provided in the A liquid pipe L14 and the mixer 32 provided in the B liquid pipe L13, respectively.

  The liquefied carbon dioxide container 20 is a container with a siphon tube in which a siphon tube L20 is provided, as shown in FIG. The container is not particularly limited, and a generally provided container can be used. For example, a container such as a small gas cylinder that has high pressure resistance and is not insulated may be used as the liquefied carbon dioxide container 20.

  Further, the liquefied carbon dioxide container 20 is provided with a heating member 21 for heating the container 20. The heating member 21 is for heating the liquefied carbon dioxide stored in the liquefied carbon dioxide container 20 to increase the pressure inside the container. Specific examples of the heating member 21 include a method of immersing a container in an electric heater, a steam heater, or a hot water tank.

  The liquefied carbon dioxide container 20 is heated by the heating member 21, and the internal pressure of the liquefied carbon dioxide container 20 is in the range of about 5 MPa to 14 MPa, preferably in the range of about 7 MPa to 14 MPa, and more preferably in the range of 7 MPa to 10 MPa. Like that. Hereinafter, the internal pressure set to the said range by heating the liquefied carbon dioxide container 20 is described as a 1st pressure. In addition, although the gas cylinder marketed normally changes with temperature conditions, since an internal pressure is about 3MPa-7MPa and is less than the said 1st pressure in winter, it heats and an internal pressure enters in the said range. Thus, it is preferable to adjust the pressure. FIG. 8 is a graph showing the temperature-pressure relationship depending on the difference in the amount of liquefied carbon dioxide in the liquefied carbon dioxide container. Each line represents a case where the filling amount is 30 kg (1), the filling amount is 26.8 kg (2), the filling amount is 23.6 kg (3), and the filling amount is 20.1 kg (4). In addition, since the inside of the liquefied carbon dioxide container 20 is heated, the phenomenon of not reaching the first pressure does not occur unless a large amount of stored liquid is extracted. That is, the container with a siphon tube has a structure in which the liquid liquefied carbon dioxide is extracted, and thus the pressure does not easily decrease. If the container is heated to about 40 ° C., the internal pressure can be set to the first pressure.

  The reason why the first pressure is set to the above value is to prevent the carbon dioxide in the liquefied carbon dioxide container 20 and the primary pipe L11 from being vaporized. The first pressure is set near the critical pressure (7.382 MPa (abs: absolute pressure)) or higher than the critical pressure depending on the temperature condition.

  The primary pipe L11 is made of, for example, a stainless steel pipe having a diameter of 6 mm, and feeds liquefied carbon dioxide supplied from the liquefied carbon dioxide container 20 while maintaining the first pressure. The filter 23 provided in the primary pipe L11 is for removing foreign substances in the primary pipe L11, and foreign substances are trapped in the needle valve 27 and the like having a narrow downstream supply path. To prevent. The first pressure gauge 25 detects the pressure in the primary pipe L11, that is, the internal pressure of the liquefied carbon dioxide container 20. Based on the detection value by the first pressure gauge 25, the heating member 21 can be controlled.

  An open / close valve 46 is provided between the primary pipe L11 and the tertiary pipe L15, and this open / close valve 46 serves as a boundary between the primary pipe L11 and the tertiary pipe L15. The tertiary pipe L15 is provided with a needle valve 47 and a third pressure gauge 48, and the opening / closing valve 46, the needle valve 47 and the third pressure gauge 48 constitute a pressure control mechanism 45. .

  The needle valve 47 provided in the tertiary pipe L15 adjusts the flow rate of the liquefied carbon dioxide fed from the primary pipe L11 to the third pipe L15. The needle valve 47 can control the pressure in the tertiary pipe L15 by adjusting the flow rate of liquefied carbon dioxide fed through the tertiary pipe L15. The adjustment of the throttle amount of the needle valve 47 can be performed manually, but may be electrically controlled.

  The third pipe L15 is made of, for example, a stainless steel pipe having a diameter of 6 mm. Since the flow rate of the liquefied carbon dioxide fed to the third pipe L15 is reduced, the third pipe L15 is in a third pressure state that is lower than the first pressure in the first pipe L11. Further, the third pressure is set to a high pressure equal to or higher than the discharge pressure (when stopped) of the spray gun 5 of the discharge device. The specific value of the third pressure is in the range of 5 MPa to 10 MPa, preferably in the range of 7 MPa to 10 MPa.

FIG. 6 is a flowchart of a pressure control method in which the pressure control mechanism 45 controls the inside of the third pipe L15 within a set pressure range of a predetermined width for the third pressure.
(A) First, turn on the power. First, the on-off valve 46 is opened (S01). As a result, liquefied carbon dioxide flows from the primary pipe L11 into the third pipe L15, and the pressure in the third pipe L15 increases.
(B) The pressure in the third pipe L15 measured by the third pressure gauge 48 is compared with a preset third pressure to determine whether it is equal to or higher than a lower limit of a set pressure having a predetermined width (S02). If it is less than the lower limit, it is considered that the flow rate of liquefied carbon dioxide is not sufficient, and the process returns to step S01. On the other hand, if the measured pressure is greater than or equal to the lower limit of the set pressure, the process proceeds to step S03.
(C) The pressure in the third pipe L15 measured by the third pressure gauge 48 is compared with whether or not the upper limit of the set pressure of a predetermined width is exceeded with respect to the preset third pressure (S03). When the upper limit of the set pressure is exceeded, the on-off valve 46 is closed (S04). If it is below the upper limit of the set pressure, the process returns to step S02.
(D) After closing the on-off valve, it is determined whether or not it is finished (S05). In the case of termination, turn off the power and terminate. On the other hand, if it is not finished, the process returns to step S03 to compare whether the upper limit of the set pressure is exceeded.
By repeating the above steps, the pressure in the tertiary pipe L15 can be controlled within a set pressure range of a predetermined width with respect to the preset third pressure. Accordingly, as shown in FIG. 8, the third pressure in the tertiary pipe L15 is different even when the first pressure for each container differs depending on the amount of liquefied carbon dioxide in the liquefied carbon dioxide container 20. The pressure can be controlled within a set pressure range, which is a low pressure equal to or lower than the first pressure. Therefore, the tertiary pipe L15 can be made to function as a pressure buffer for a large fluctuation in the first pressure of the primary pipe L11. For this reason, the flow rate of the liquefied carbon dioxide flowing through the secondary pipe L12 can be kept constant regardless of the filling amount.

  Note that the accuracy of pressure control becomes coarser as the set pressure range becomes wider, and the accuracy of pressure control improves as the set pressure range becomes narrower. The on-off valve 46 preferably includes a regulating valve made of a linear motion type closing part. In other words, this is a configuration for controlling the supply and stop of liquefied carbon dioxide fed by a regulating valve comprising a linear motion type closing part. With the above configuration, even when the number of times of opening / closing the valve is increased, the durability can be maintained high, and the frequency of replacement of the opening / closing valve components is reduced compared to a rotary closing component such as a ball valve. Because it can. In addition, in the linear motion type closing part, a proportional control type valve that can be controlled not only in two stages of complete opening and complete closing but also in an intermediate opening / closing state can be used. That is, when the pressure measured by the pressure gauge exceeds a predetermined pressure, the on-off valve is controlled to be completely closed or closed (the direction in which the flow rate is reduced), and when the pressure measured by the pressure gauge is lower than the predetermined pressure. It is preferable that it is a valve control means for controlling the on-off valve in a direction to fully open or open (direction to increase the flow rate). In this case, the needle valve 47 is unnecessary.

  An open / close valve 26 is provided between the tertiary pipe L15 and the secondary pipe L12, and this open / close valve 26 serves as a boundary between the tertiary pipe L15 and the secondary pipe L12. The secondary pipe L12 is provided with a needle valve 27 and a second pressure gauge 28, and the on-off valve 26 and the needle valve 27 constitute a flow rate adjusting mechanism 15. The on-off valve 26 is a member that connects the tertiary pipe L15 and the secondary pipe L12, and is electrically controlled to open and close by the control unit 10 described later. The on-off valve 26 also serves as a pressure adjustment function for the tertiary pressure system on the upstream side of the on-off valve 26 and the secondary pressure system on the downstream side. That is, the pressure in the tertiary pipe L15 and the secondary pipe L12 connected to both ends of the on-off valve 26 is different.

  The needle valve 27 provided in the secondary pipe L12 adjusts the flow rate of the liquefied carbon dioxide fed from the tertiary pipe L15 to the secondary pipe L12, such as the outside temperature and the degree of foaming of the polyurethane foam. The amount of liquefied carbon dioxide fed to the secondary pipe L12 is adjusted according to the usage environment of the apparatus. The adjustment of the throttle amount of the needle valve 27 can be performed manually, but may be electrically controlled.

  The check valve 29 provided in the secondary pipe L12 is a flow direction of the liquefied carbon dioxide so that the B liquid in the B liquid pipe L13 communicating with the mixer 31 does not flow into the secondary pipe L12. To regulate.

  The secondary pipe L12b has a small diameter smaller than that of the tertiary pipe L15. In the present embodiment, the secondary pipe L12b is made of, for example, a stainless steel pipe having a diameter of 3 mm. That is, since the flow rate of liquefied carbon dioxide is different between the upstream side and the downstream side of the needle valve 27, the secondary pipe L12b can be made to have a small diameter to reduce the pressure drop. Since the flow rate of the liquefied carbon dioxide to be fed is reduced, the secondary pipe L12 is in a state of the second pressure lower than the third pressure in the tertiary pipe L15. The specific value of the second pressure is in the range of 4 MPa to 7 MPa, preferably in the range of 5 MPa to 6 MPa, and is preferably substantially the same as the discharge pressure (when stopped) of the spray gun 5 of the discharge device.

  The B liquid pipe L <b> 13 and the A liquid pipe L <b> 14 feed the B liquid and the A liquid to the spray gun 5 at the pressures pressurized by the pumps 31 and 41, respectively.

  Examples of the polyisocyanate that is the main component of the liquid A include aromatic polyisocyanate, aliphatic diisocyanate, alicyclic diisocyanate, and a part of the isocyanate group of aromatic polyisocyanate, aliphatic diisocyanate, or alicyclic diisocyanate. What modified | denatured to urethane and / or urea may be used, and what modified a part of isocyanate group into burette, allophanate, carbodiimide, oxaziridone, acid, imide, etc. may be used.

  Examples of the polyol which is the main component of the liquid B include ethylene glycol, propanediol, butanediol, diethylene glycol, dipropylene glycol, tetramethylene glycol, hexamethylene glycol, cyclohexanedimethanol, bisphenol A, 3-methyl-1, 5 -At least 1 sort (s) is mentioned among compounds which have active hydrogen, such as pentanediol, glycerin, trimethylol propane, pentaerythritol, sucrose, glucose, fructose sorbitol, methylglycoxide. Further, for example, the other active hydrogen-containing compound includes at least one of amines such as ethylenediamine, propylenediamine, diethylenetriamine, toluenediamine, metaphenylenediamine, diphenylmethanediamine, xylylenediamine, and the like. .

  Furthermore, a polyether polyol may be used as the active hydrogen group-containing compound. As the polyether polyol, for example, a monomer such as alkylene oxide is known by using at least one of the above-exemplified active hydrogen compounds as an initiator. What is obtained by addition polymerization by a method is mentioned. Examples of the monomer used for the addition polymerization reaction include ethylene oxide, propylene oxide, glycidyl ether, methyl glycidyl ether, t-butyl glycidyl ether, and phenyl glycidyl ether.

  Further, a polyester polyol may be used as the active hydrogen group-containing compound. Examples of the polyester polyol include ethylene glycol, propanediol, butanediol, diethylene glycol, dipropylene glycol, trimethylene glycol, tetramethylene glycol, and hexamethylene glycol. , Decamethylene glycol, neopentyl glycol, 3-methyl-1,5-pentanediol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, at least two compounds having a hydroxyl group such as bisphenol A 1 type, for example, adipic acid, malonic acid, succinic acid, tartaric acid, pimelic acid, sebacic acid, oxalic acid, phthalic acid, terephthalic acid, azelaic acid, Use at least one of compounds having at least two carboxyl groups such as merit acid, glutaconic acid, α-hydromuconic acid, β-diethylsuccinic acid, hemimellitic acid, 1,4-cyclohexanedicarboxylic acid, etc. And those produced by known methods.

  Furthermore, in addition to the above polyester polyol, a polyester polyol produced by transesterification of a polyalkylene terephthalate polymer and a low molecular diol can also be used. Examples of the low molecular weight diol include ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, butanediol, glycerol, trimethylolpropane, and cyclohexanedimethanol.

  The catalyst for proceeding the urethanation reaction between the polyisocyanate and the active hydrogen group-containing compound is not particularly limited, and for example, a known catalyst can be used. Further, the foam stabilizer is not particularly limited, and for example, all those used in the production of polyurethane foam can be used. Further, additives such as a catalyst, a foam stabilizer, a flame retardant and the like are usually mixed on the B liquid side. The polyurethane foam of the present invention includes polyisocyanurate foam.

  The pressure in the B liquid pipe L13 and the A liquid pipe L14, that is, the discharge pressure of the spray gun 5 is controlled by the pumps 31 and 41 to be constant (4 MPa to 6 MPa). The pressure in the B liquid pipe L13 and the A liquid pipe L14 varies because the B liquid and the A liquid pulsate in the B liquid pipe L13 and the A liquid pipe L14 by driving the pump. When the pump is stopped, the pressure is about 5 MPa. That is, the pumps 31 and 41 are configured to always supply the B liquid and the A liquid from the polyol component storage container 30 and the polyisocyanate component storage container 40 at a constant pressure by a pressure adjusting mechanism 50 such as hydraulic pressure. When the spray gun 5 is operated and the liquid in the B liquid pipe L13 and the A liquid pipe L14 is consumed, the discharge pressure in the B liquid pipe L13 and the A liquid pipe L14 decreases. Is driven to adjust the discharge pressure to be constant.

  As described above, the internal pressure in the secondary pipe L12 is adjusted so that the liquefied carbon dioxide is fed by the on-off valve 26 and the opening degree (throttle amount) of the needle valve 27 is adjusted. As a result, the pressure is reduced to the second pressure (substantially the same as the discharge pressure). Therefore, the secondary pressure system in the secondary pipe L12, the B liquid pipe L13, and the A liquid pipe L14 adjusts the pressures of the A liquid and the B liquid by the operation of the pumps 31 and 41, and is controlled by the on-off valve 26. The flow rate of liquefied carbon dioxide supplied from the tertiary pressure system in the tertiary pipe L15 is adjusted by switching of opening and closing and the needle valve 27, and the pressure of the liquefied carbon dioxide is adjusted. As a result, the pressure of the secondary pressure system is adjusted. It can be made almost uniform.

  Specifically, the adjustment of the flow rate of the liquefied carbon dioxide can be automated by interlocking the operation of the pumps 31 and 41 and the switching of the opening and closing of the on-off valve 26, and the polyurethane foam manufacturing apparatus according to the present embodiment Then, the control unit 10 is configured to automate this adjustment. Details of the operation of the control unit 10 will be described later.

  In addition, due to the pulsation of the pumps 31 and 41, the pressure in the B liquid pipe L13 and the A liquid pipe L14, that is, the discharge pressure of the spray gun 5 may be temporarily higher than the pressure in the secondary pipe L12. Although possible, the backflow of the B liquid and / or the A liquid into the secondary pipe L <b> 12 in that case is prevented by the check valve 29.

(Modification)
Note that the flow rate adjusting mechanism 15 can also be configured as a modified example as shown in FIGS. In the example shown in FIG. 2, the flow rate adjusting mechanism 15 is configured only by the needle valve 27, and the control unit 10 adjusts the degree of opening (throttle amount) of the needle valve 27. That is, based on operating conditions such as the outside air temperature, information on the operation of the pumps 31 and 41 that operate according to the pressure of the B liquid pipe L13 and the A liquid pipe L14, the pressure in the secondary pipe L12, and the like. The opening degree of the needle valve 27 is adjusted. At this time, the needle valve 27 is preferably provided with an opening / closing mechanism capable of completely stopping the flow of liquefied carbon dioxide between the tertiary pipe L15 and the secondary pipe L12. That is, when the supply of liquefied carbon dioxide cannot be stopped with the needle valve 27 being most throttled, the liquefied carbon dioxide is continuously supplied into the secondary pipe L12 by leaving the apparatus in a standby state. It will be. As a result, the pressure in the secondary pipe L12 becomes too high, and excessive carbon dioxide is supplied to the discharge device 2 to foam the polyurethane foam, making it difficult to produce an appropriate polyurethane foam.

  3 is an example in which the control device 10 adjusts the degree of opening of the needle valve 27 in addition to the opening and closing of the on-off valve 26. As described above, the difference from the example of FIG. 1 is that the degree of opening of the needle valve 27 is set manually according to operating conditions such as the outside air temperature, whereas in the modified example of FIG. The degree of opening is to be automated by control from the control device 10.

<Polyurethane foam manufacturing method>
<Preparation procedure>
Next, the operation of the polyurethane foam manufacturing apparatus according to the first embodiment will be described. First, the preparation procedure performed before manufacturing a polyurethane foam using the polyurethane foam manufacturing apparatus which concerns on this Embodiment is demonstrated.

  In the polyurethane foam manufacturing apparatus according to the first embodiment, first, the liquefied carbon dioxide container 20, the polyol component storage container 30, and the polyisocyanate component storage container 40, which are raw materials, are connected, and then each of the B liquids is placed in the pipes L13 and L14. And A liquid is filled.

  Next, liquefied carbon dioxide is filled from the primary pipe L11 to the tertiary pipe L15. In this operation, the on-off valve 46 and the needle valve 47 are opened, and liquefied carbon dioxide is fed from the primary pipe L11 into the tertiary pipe, but air is supplied from the primary pipe to the tertiary pipe. Therefore, unless one end is opened, liquefied carbon dioxide cannot be filled. Therefore, in the polyurethane foam manufacturing apparatus 1 according to the first embodiment, the blow valve 24 is provided in the tertiary pipe L15, and liquefied carbon dioxide is filled into the tertiary pipe L15 from the primary pipe L11. For this reason, the position where the blow valve 24 is provided is preferably in the vicinity of the upstream side of the on-off valve 26 at the boundary between the tertiary pipe L15 and the secondary pipe L12.

  Thereafter, the liquefied carbon dioxide container 20 is heated by the heating member 21, and the pressure in the primary pipe L11 is adjusted to the range of 7 MPa to 14 MPa. The temperature control of the heating member 21 may be configured to be controlled by a computer so as to maintain a predetermined first pressure based on the output value of the first pressure gauge 25, for example.

  Next, the pressure in the tertiary pipe L15 is controlled by the pressure control mechanism 45 within a set pressure range of a predetermined width with respect to the third pressure according to the flowchart of FIG.

  Thereafter, the on-off valve 26 and the needle valve 27 of the secondary pipe L12 are opened to fill the secondary pipe L12 with the liquefied carbon dioxide from the tertiary pipe L15, and the degree of opening of the needle valve 27 is adjusted. . The pressure in the secondary pipe L12 naturally decreases due to a decrease in the flow rate of liquefied carbon dioxide, and substantially balances with the pressure (4 MPa to 6 MPa) in the B liquid pipe L13 and the A liquid pipe L14. The degree of opening of the needle valve 27 may be adjusted by, for example, the temperature at which the polyurethane foam manufacturing apparatus is used. For example, the flow rate of liquefied carbon dioxide is increased when the temperature is low, and the flow rate is decreased when the temperature is high. Can be adjusted. When the pressure in the secondary pipe L12 is set to a predetermined pressure, the on-off valve 26 is closed.

  In addition, adjusting the 1st pressure to the range of 7 MPa-14 MPa as mentioned above is based on the phase state of a carbon dioxide. That is, carbon dioxide has a phase diagram as shown in FIG. 5 and has a critical point (7.382 MPa (abs), 31.1 ° C.). Therefore, as long as the high pressure around this critical pressure is maintained, carbon dioxide does not become a gas. Therefore, by setting the first pressure to 7 MPa to 14 MPa, the liquid state can be maintained if the temperature in the primary pipe L11 is about 20 ° C.

  In general, the discharge pressure of the discharge device 2 is said to be about 4 MPa to 7 MPa, preferably about 5 MPa to 8 MPa. When the second pressure is set lower than this, liquefied carbon dioxide is supplied to the B liquid supply pipe. It cannot be supplied.

  Further, the third pressure in the tertiary pipe L15 is set to a low pressure equal to or lower than the first pressure and a high pressure equal to or higher than the second pressure, for example, in a range of 5 MPa to 10 MPa.

<Polyurethane foam manufacturing process>
When the above preparation process is completed, polyurethane foam is manufactured by a polyurethane foam manufacturing apparatus. FIG. 7 is a flowchart of the polyurethane foam manufacturing process.
(A) Specifically, the spray gun 5 is operated and the liquid mixture of the liquid A and the liquid B is discharged from the spray gun 5. The discharge from the spray gun 5 consumes the A and B liquids in the A liquid pipe L14 and the B liquid pipe L13 and the liquefied carbon dioxide in the secondary pipe L12. descend. When the discharge pressure becomes lower than the set pressure (5 MPa) (# 10), the pumps 31 and 41 are driven (# 11).
(B) Liquid A and liquid B are fed into the liquid A pipe L14 and the liquid B pipe L13. The pumps 31 and 41 are provided with a switch. When the pump is operated, a signal is sent to the control unit to switch the opening / closing valve 26 (# 21).
(C) Liquefied carbon dioxide is fed into the secondary pipe L12. At this time, the flow rate of the liquefied carbon dioxide is limited by the needle valve 27, and the inside of the secondary pipe L12 is adjusted to the secondary pressure (# 22).

  When the discharge pressure reaches a predetermined pressure due to the operation of the pumps 31 and 41 (# 12), the operation of the pump is stopped (# 13). Then, the control unit 10 detects that the pump has stopped, and performs control to close the on-off valve 26 (# 23).

  In this way, by switching the opening and closing of the on-off valve 26 according to the supply operation of the liquid A and the liquid B, the liquefied carbon dioxide is fed from the high pressure side tertiary pressure system to the low pressure side secondary pressure system. Is done. The needle valve 27 adjusts the flow rate of the liquefied carbon dioxide to lower the pressure in the secondary pressure system, that is, the flow rate adjusting mechanism 15 serves as a partition wall between the tertiary pressure system and the secondary pressure system. And has a function of setting an appropriate supply amount of carbon dioxide under the control of the control unit 10.

(effect)
As described above, according to the polyurethane foam manufacturing apparatus according to the first embodiment, the liquefied carbon dioxide container is heated and the first pressure is set to be higher than the discharge pressure of the spray gun 5. Specifically, the first pressure is set in the range of 5 MPa to 14 MPa, preferably 7 MPa to 14 MPa and higher than the critical pressure, thereby preventing the carbon dioxide container from being vaporized and feeding it without cooling it. Can do.

  Further, a tertiary pipe L15 is provided between the primary pipe L11 and the secondary pipe L12, and an opening / closing valve 46 is provided between the primary pipe L11 and the tertiary pipe L15. Yes. The tertiary pipe L15 is provided with a needle valve 47 and a third pressure gauge 48. As a pressure buffer that absorbs the fluctuation of the first pressure that changes according to the filling amount of the liquefied carbon dioxide container 20 by the pressure control mechanism 45 configured by the on-off valve 46, the needle valve 47, and the third pressure gauge 48, The tertiary piping L15 can be functioned. As a result, regardless of the amount of liquefied carbon dioxide in the liquefied carbon dioxide container 20, the inside of the third pipe L15 can be controlled to a substantially constant third pressure.

  Furthermore, by adjusting the flow rate of liquefied carbon dioxide from the tertiary pipe L15 to the secondary pipe L12, the pressure can be reduced from the third pressure to the second pressure. Therefore, the first pipe L11 is connected to the discharge device 2 via the third pipe L15 and the second pipe L12, and the first pressure of the first pipe L11 and the third pressure of the third pipe L15 are communicated. With regard to the pressure and the second pressure of the secondary pipe L12, by supplying a pressure difference between the respective pipes and using this pressure difference as the conveying force, the liquefied carbon dioxide can be fed without using a pump. Can do. Therefore, the problem of vaporization of carbon dioxide due to use of the pump can be avoided.

  As shown in FIG. 3, as a specific configuration of the flow rate adjusting mechanism 15, when a single on-off valve 26 and a needle valve 27 are combined, the control valve 10 receives a control signal from the control unit 10. Both opening and closing and the opening degree of the needle valve 27 are controlled.

  By combining the on-off valve 26 and the needle valve 27 in this way, the flow of the liquefied carbon dioxide can be easily switched by the on-off valve 26, and the needle valve 27 can be opened according to the ambient temperature, for example. The degree can be adjusted automatically. Therefore, liquefied carbon dioxide can be supplied to the secondary pressure system more easily and with high accuracy.

  In addition, this invention is not limited to the said embodiment, It can implement in another various aspect.

  The polyurethane foam manufacturing apparatus according to the present invention sets the third pressure in the tertiary pipe even when the first pressure for each container differs depending on the filling amount of the liquefied carbon dioxide in the liquefied carbon dioxide container. It is a low pressure of 1 pressure or less, and the pressure can be controlled within a set pressure range. Therefore, the tertiary pipe can be made to function as a pressure buffer for a large fluctuation in the first pressure of the primary pipe. For this reason, the flow rate of the liquefied carbon dioxide flowing through the secondary pipe can be kept constant regardless of the filling amount in the liquefied carbon dioxide container, and the water as the blowing agent added to the liquefied carbon dioxide and the normal B liquid side. The amount of foam can be stabilized, a well-balanced foaming state and foaming ratio can be exhibited, and a polyurethane foam can be stably obtained. Therefore, the present invention is useful as a polyurethane foam production apparatus suitable for polyurethane foam foaming using liquid carbon dioxide as a foaming agent.

DESCRIPTION OF SYMBOLS 1 Polyurethane foam manufacturing apparatus 2 Discharge apparatus 3 Heating machine 4 Hose heater 5 Play gun 10 Control part 20 Liquefied carbon dioxide container 21 Heating member 22 Connector 23 Filter 24 Blow valve 25 First pressure gauge 26 On-off valve 27 Needle valve 28 Second pressure Total 29 Check valve 30 Polyol component storage container 31 B liquid pumps 32, 42 Mixer 40 Polyisocyanate component storage container 41 A liquid pump 45 Pressure control mechanism 46 On-off valve 47 Needle valve 48 Third pressure gauge L11 Primary Piping L12, L12a, L12b Secondary piping L13 B liquid piping L14 A liquid piping

Claims (9)

When producing polyurethane foam by mixing A liquid mainly composed of polyisocyanate, B liquid mainly composed of polyol, and liquefied carbon dioxide as a blowing agent supplied from a liquefied carbon dioxide container, respectively. A polyurethane foam manufacturing apparatus comprising a discharge device that mixes the liquefied carbon dioxide with the liquid A and / or liquid B fed through a pipe, mixes the liquid A and liquid B, and discharges the liquid at a predetermined discharge pressure. Because
A primary pipe having a first end connected to the liquefied carbon dioxide container having a first pressure higher than the discharge pressure in the container and transporting the liquefied carbon dioxide from the liquefied carbon dioxide container while maintaining the first pressure. When,
The terminal side is connected to the supply pipe of at least one of the A liquid and the B liquid, and the liquefied carbon dioxide is supplied to the supply pipe of at least one of the A liquid and the B liquid at a second pressure lower than the first pressure. Secondary piping to feed,
A start end side is connected to a terminal end side of the primary pipe, a terminal end side is connected to a start end side of the secondary pipe, and the third pressure is a low pressure equal to or lower than the first pressure and a high pressure equal to or higher than the second pressure. And a tertiary pipe for conveying liquefied carbon dioxide from the primary pipe to the secondary pipe;
The third pipe is connected between the terminal end side of the primary pipe and the start end side of the third pipe, and the flow rate of liquefied carbon dioxide from the primary pipe to the third pipe is adjusted, and the third pipe is adjusted. Pressure control means for controlling the inside of the next pipe to exhibit the third pressure;
It is connected between the terminal end side of the tertiary piping and the starting end side of the secondary piping, and flows through the secondary piping so that the flow rate in the secondary piping exhibits the second pressure. A flow rate adjusting means for adjusting the flow rate of the liquefied carbon dioxide,
Heating means for heating the liquefied carbon dioxide container to pressurize the liquefied carbon dioxide container to the first pressure higher than the discharge pressure;
Equipped with a,
The discharge device is a spray gun,
Wherein the first pressure is in the range of 5MPa～14MPa, the third pressure is in the range of 5MPa～10MPa, the second pressure and said discharge pressure, and wherein the range der Rukoto of 4MPa~7MPa The polyurethane foam manufacturing equipment. The pressure control means includes
An on-off valve that can be switched between opening and closing;
A pressure gauge for measuring the pressure in the tertiary pipe;
When the pressure measured by the pressure gauge exceeds the upper limit of the predetermined range including the third pressure, the on-off valve is closed, and when the pressure measured by the pressure gauge is equal to or lower than the upper limit of the predetermined range including the third pressure Valve control means for opening the on-off valve;
The polyurethane foam manufacturing apparatus according to claim 1, comprising:   3. The polyurethane foam manufacturing apparatus according to claim 2, wherein the pressure control means includes an on-off valve composed of a regulating valve composed of a linear motion type closing part.   3. The polyurethane foam manufacturing apparatus according to claim 2, wherein the pressure control unit includes a throttle valve capable of adjusting a flow rate of liquefied carbon dioxide from the primary pipe to the third pipe.   The polyurethane foam manufacturing apparatus according to claim 4, wherein the throttle valve of the pressure control means is constituted by a needle valve whose degree of throttle is controlled by the valve control means of the pressure control means. The flow rate adjusting means is
An on-off valve that can be switched between opening and closing;
When the A and B liquids are not discharged from the discharge device, the on-off valve is closed, while the on-off valve is controlled to open in conjunction with the operation of supplying the A and B liquids into the discharge device. Valve control means;
The polyurethane foam manufacturing apparatus according to claim 1, comprising:   The polyurethane foam manufacturing apparatus according to claim 6, wherein the flow rate adjusting unit includes a throttle valve capable of adjusting a flow rate of liquefied carbon dioxide from the tertiary pipe to the secondary pipe. The polyurethane according to any one of claims 1 to 7 , further comprising a blow valve for filling the liquefied carbon dioxide from the primary pipe into the tertiary pipe. Form manufacturing equipment. When a polyurethane foam is produced by mixing A liquid mainly composed of polyisocyanate, B liquid mainly composed of polyol, and liquefied carbon dioxide as a blowing agent supplied from a liquefied carbon dioxide container, The liquefied carbon dioxide is transported from the carbon dioxide container through the primary piping, the tertiary piping, and the secondary piping by the respective pressure differences of the primary piping, the tertiary piping, and the secondary piping. Polyurethane foam using a polyurethane foam manufacturing apparatus equipped with a spray gun that is a discharge device that mixes the liquefied carbon dioxide with the liquid A and / or liquid B, stores the liquid carbon dioxide therein, and discharges the liquid carbon dioxide at a predetermined discharge pressure. A method of manufacturing
Heating the liquefied carbon dioxide container and pressurizing the liquefied carbon dioxide container to a first pressure higher than the discharge pressure;
The liquefied carbon dioxide in the liquefied carbon dioxide in a container interior having a first pressure of the high pressure from the discharge pressure, maintaining said first pressure through the first primary in the pipe starting side is connected to the liquefied carbon dioxide container While carrying
The on-off valve between the primary pipe and the tertiary pipe is controlled to open and close, the pressure in the tertiary pipe is controlled to a third pressure lower than the first pressure, and the third In the next pipe, the liquefied carbon dioxide is conveyed at the third pressure,
The flow rate of liquefied carbon dioxide sent out from the tertiary pipe is adjusted and supplied into the secondary pipe, and the liquefied carbon dioxide is passed through the secondary pipe at a second pressure lower than the third pressure. Transport the
Supplying the liquefied carbon dioxide conveyed in the secondary pipe to the supply pipe of the liquid A and / or liquid B in the state of the second pressure;
In a state where the liquefied carbon dioxide and the A liquid and / or B liquid are mixed, the A liquid and the B liquid are mixed and discharged in the discharge device, and the liquefied carbon dioxide is vaporized to foam polyurethane foam. Manufacture and
Wherein the first pressure is in the range of 5MPa～14MPa, the third pressure is in the range of 5MPa～10MPa, the second pressure and said discharge pressure, and wherein the range der Rukoto of 4MPa~7MPa A method for producing a polyurethane foam.

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