JP2023095553A - Forming agent addition device, foaming machine for spraying, forming agent addition method, and manufacturing method for foamed body - Google Patents

Abstract

To provide a foaming agent addition device capable of stably adding a foaming agent to a liquid, a foaming machine for spraying, method for adding foaming agent, and method for manufacturing a foamed body.SOLUTION: There is provided a foaming agent addition device 10 for adding a foaming agent to a liquid that is supplied by a liquid pump 40 and flows through a liquid channel 30. The foaming agent addition device comprises: a pressure gauge 31 for a liquid L1 flowing through the liquid channel; a foaming agent container 11 in which a foaming agent E is stored; a foaming agent channel 12 for flowing the foaming agent supplied from the foaming agent container; a foaming agent pressurizing pump 80; a pressure gauge 90 for the foaming agent flowing through the foaming agent channel; an on-off valve 50 that controls connection between the foaming agent channel and the liquid channel by opening and closing the valve, and controls addition of the foaming agent to the liquid by opening and closing the valve; a flow rate adjustment mechanism 60 for adjusting a flow rate of the foaming agent in the foaming agent channel upstream of the on-off valve; and a control unit 51 that opens the on-off valve when a foaming agent pressure EP measured by a foaming agent channel pressure gauge is higher than a liquid pressure LP measured by a liquid channel pressure gauge.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a foaming agent addition device for adding a foaming agent to a liquid, a blowing foaming machine, a foaming agent addition method, and a foam manufacturing method.

BACKGROUND ART Conventionally, a construction method is widely known in which a polyol and an isocyanate are mixed on-site to the roof, wall surface, floor, etc. of a building or structure, and the mixture is sprayed to foam to form a polyurethane foam. As a method for assisting the workability of polyurethane foam, for example, when two components, polyol and isocyanate, are mixed, a method of adding a foaming agent as a third component (hereinafter referred to as "floss method") is widely known. In the froth method, for example, a foaming agent channel connected to a liquid channel for supplying polyol or isocyanate is provided, and a foaming agent such as carbon dioxide is introduced into the liquid channel from a tank or the like through the foaming agent channel. Blowing agent addition equipment is commonly used to add polyols or isocyanates in the air. The polyol or isocyanate added with the foaming agent such as carbon dioxide in the foaming agent addition device is further mixed with the isocyanate or the polyol and discharged to the outside.

The liquid in the liquid channel of the foaming agent addition device is generally supplied in a pressurized state, and the foaming agent is pressurized to a pressure higher than the pressure of the liquid in the liquid channel. By adding it to the channel, it can be stably mixed with the liquid. Therefore, there is control to measure the liquid pressure in the liquid channel and the foaming agent pressure in the foaming agent channel, and open the on-off valve to add the foaming agent to the liquid when the foaming agent pressure is higher than the liquid pressure. is used (see, for example, Patent Document 1).

Japanese Patent No. 6395556

In the conventional blowing agent addition device, the blowing agent pressure must be higher than the liquid pressure as a condition for adding the blowing agent. The addition of the foaming agent to the liquid is controlled by detecting the liquid pressure in the liquid channel and using the differential pressure between the liquid pressure and the foaming agent pressure as a driving force for addition of the foaming agent. ing. In the control that uses the differential pressure between the liquid pressure and the blowing agent pressure as the driving force for adding the blowing agent, when the blowing agent pressure increases under high temperature such as in summer, the amount of blowing agent added from the blowing agent container to the liquid is controlled. Since the flow path is connected to the on-off valve that controls , the foaming agent having a higher pressure than the liquid pressure tends to be excessively added, making it difficult to adjust the amount of the foaming agent added.

Therefore, the present invention provides a foaming agent addition device, a blowing foaming machine, a foaming agent addition method, and a foam that can stably add a foaming agent to a liquid without excessive addition at high temperatures such as in summer. An object is to provide a manufacturing method.

The gist of the present invention is the following [1] to [13].
[1] A foaming agent addition device for adding a foaming agent to a liquid supplied by a liquid pump and flowing through a liquid flow path, wherein the liquid pressure of the liquid flowing through the liquid flow path is measured. a channel pressure gauge, a foaming agent container containing the foaming agent, a foaming agent channel for flowing the foaming agent supplied from the foaming agent container, and increasing the foaming agent pressure in the foaming agent channel to a predetermined pressure. a foaming agent pressurizing pump that presses, a foaming agent channel pressure gauge that measures the foaming agent pressure of the foaming agent flowing through the foaming agent channel, and a connection between the foaming agent channel and the liquid channel that is controlled by opening and closing. an on-off valve that controls addition of the foaming agent to the liquid by opening and closing; a flow rate adjustment mechanism that adjusts the flow rate of the foaming agent to the foaming agent flow path on the upstream side of the on-off valve; a controller that opens the on-off valve when the foaming agent pressure measured by the flow path pressure gauge is higher than the liquid pressure measured by the liquid flow path pressure gauge. .
[2] The foaming agent addition device according to [1], wherein the flow rate adjustment mechanism is a second on-off valve that controls the flow rate of the foaming agent flowing through the foaming agent flow path on the upstream side of the on-off valve by opening and closing. .
[3] The foaming agent addition device according to [1] or [2], wherein the foaming agent pressurizing pump pressurizes the foaming agent so that the pressure of the foaming agent is higher than the liquid pressure by a predetermined value.
[4] The control unit according to any one of [1] to [3], wherein after controlling to open the on-off valve, the control unit performs control to close the on-off valve after a predetermined time has elapsed. blowing agent addition device.
[5] The foaming agent addition device according to any one of [1] to [4], wherein the foaming agent pressurizing pump is a pump that continuously pressurizes the foaming agent.
[6] The foaming agent addition device according to any one of [1] to [5], wherein the foaming agent pressure pump is either an axial pump or a gear pump.
[7] Further comprising a pump driving detection section for detecting driving of the liquid pump, the pump driving detection section detecting that the liquid pump reaches the top dead center or the bottom dead center, the control section The foaming agent addition device according to any one of [1] to [6], which controls opening of the on-off valve.
[8] The blowing agent addition device according to any one of [1] to [7], wherein the liquid contains polyol or polyisocyanate.
[9] The foaming agent addition device according to any one of [1] to [8], wherein the liquid contains a filler.
[10] The blowing agent addition device according to any one of [1] to [9], wherein the blowing agent contains carbon dioxide.
[11] A spray foaming machine comprising the foaming agent addition device according to any one of [1] to [10].
[12] A foaming agent addition method for adding a foaming agent to a liquid supplied by a liquid pump and flowing through a liquid channel, wherein the foaming agent contained in a foaming agent container is supplied to the foaming agent channel. measuring the foaming agent pressure of the foaming agent flowing through the foaming agent channel with a foaming agent channel pressure gauge; and measuring the liquid pressure of the liquid flowing through the liquid channel with a liquid channel pressure gauge. a step of increasing the pressure of the foaming agent in the foaming agent channel to a predetermined pressure with a foaming agent pressurizing pump; and controlling the connection between the foaming agent channel and the liquid channel by opening and closing an on-off valve. a step of controlling the addition of the foaming agent to the liquid by opening and closing the on-off valve; and adjusting the flow rate of the foaming agent by a flow rate adjusting mechanism provided in the foaming agent flow path on the upstream side of the on-off valve. and in the step of controlling addition of the foaming agent by opening and closing an on-off valve, the foaming agent pressure measured by the foaming agent flow path pressure gauge is measured by the liquid flow path pressure gauge. A method for adding a foaming agent, wherein the controller controls the on-off valve to open when the pressure is higher than the liquid pressure.
[13] A method for producing a foam, comprising the step of adding a foaming agent to the liquid flowing through the liquid flow path by the method for adding a foaming agent according to [12].

In the present invention, a foaming agent addition device, a blowing foaming machine, a method for adding a foaming agent, and a method for producing a foam, which can stably add a foaming agent to a liquid without excessive addition at high temperatures such as in summer. can provide a method.

1 is a schematic diagram (part 1) showing a foaming agent addition device according to a first embodiment of the present invention; FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the blowing foaming machine which concerns on the 1st Embodiment of this invention. 4 is a flow chart showing a foaming agent addition method according to the first embodiment of the present invention. FIG. 2 is a schematic diagram (part 2) showing the foaming agent addition device according to the first embodiment of the present invention. FIG. 2 is a schematic diagram (part 1) showing a foaming agent addition device according to a second embodiment of the present invention; FIG. 2 is a schematic diagram (part 2) showing a foaming agent addition device according to a second embodiment of the present invention; Flowchart showing a foaming agent addition method according to a second embodiment of the present invention FIG. 5 is a schematic diagram showing a foaming agent addition device according to another embodiment of the present invention;

[First Embodiment]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
A foaming agent addition device 10 according to the first embodiment is a device for mixing a foaming agent E with a liquid L1 flowing in a liquid flow path 30, as shown in FIG.

<Liquid>
Although the liquid L1 is not particularly limited, it is preferably a foam raw material that is a raw material of a foam. The foaming agent addition device 10 can manufacture a foam by mixing the foaming agent E with the liquid L1, which is the foam raw material. Foams include polyurethane foams, phenolic foams, polystyrene foams, and the like. Therefore, the liquid L1 may be any liquid as long as it can be used as a raw material for these foams. Among the foams described above, polyurethane foam is preferable from the viewpoint of ease of production, curing speed, foamability, and the like. Moreover, it is more preferable that the polyurethane foam is a rigid polyurethane foam. The use of rigid polyurethane foam tends to improve self-adhesiveness, heat insulation, mechanical strength, and the like.

A urethane resin composition for forming a polyurethane foam is generally prepared by mixing one liquid containing a polyol and two liquids containing a polyisocyanate. The urethane resin composition is foamed with a foaming agent E mixed in the composition and cured to form a polyurethane foam. The foaming agent E may be mixed with either one of liquid 1 and liquid 2, but is preferably mixed with liquid 1 from the viewpoint of stability. That is, the foaming agent addition device 10 preferably mixes the liquid foaming agent E with a liquid (1 liquid or 2 liquids) containing either a polyol or a polyisocyanate. It is more preferable to mix the blowing agent E with the above.
The polyol-containing liquid (1 liquid) is preferably a polyol composition containing a catalyst and a foam stabilizer in addition to the polyol, and may further contain a foaming agent. The foaming agent preliminarily contained in the first liquid (polyol composition) is also referred to as an "internal foaming agent" in order to distinguish it from the foaming agent E described above.

Moreover, the urethane resin composition for forming a polyurethane foam may contain a filler. Including a filler in the urethane resin composition improves the flame retardancy of the obtained polyurethane foam. It is preferable to mix a filler with a liquid (liquid 1 or 2) containing either a polyol or a polyisocyanate, but it is more preferable to mix a filler with a liquid (liquid 1) containing a polyol.
A filler is contained as a solid content in a liquid raw material composition, and is generally a component present in the raw material composition in the form of granules or powder.
The filler may be a component that is solid at normal temperature (23° C.) and normal pressure (1 atm) and does not dissolve in the liquid raw material composition.
Fillers include solid flame retardants and anti-settling agents. Examples of solid flame retardants include red phosphorus flame retardants, boron-containing flame retardants, bromine-containing flame retardants, phosphate-containing flame retardants, chlorine-containing flame retardants, antimony-containing flame retardants, metal hydroxides and needle-like fillers. and preferably at least one selected from the group consisting of red phosphorus flame retardants, boron-containing flame retardants and bromine-containing flame retardants.

In addition to curing catalysts, foam stabilizers, and fillers, polyol compositions include flame retardants (solid flame retardants, liquid flame retardants), antioxidants, heat stabilizers, metal damage inhibitors, antistatic agents, and cross-linking agents. , lubricants, softeners, pigments and the like.

<Blowing agent>
The internal foaming agent is not particularly limited, but hydrofluoroolefins (HFO), hydrofluorocarbons (HFC), hydrocarbons, diethyl ether and the like can be used. Examples of the hydrofluoroolefin (HFO) used in the internal foaming agent include fluoroalkenes having about 3 to 6 carbon atoms, preferably 3 or 4 carbon atoms, more preferably 3 to 6 carbon atoms. has 3 carbon atoms. The hydrofluoroolefin may be a hydrochlorofluoroolefin having chlorine atoms. Hydrofluorocarbons (HFCs) include, for example, hydrofluorocarbons having about 1 to 4 carbon atoms, and the hydrofluorocarbons may have chlorine atoms. Hydrocarbons include hydrocarbons having 2 to 5 carbon atoms. Hydrocarbons having 2 to 5 carbon atoms are preferably hydrocarbons having 3 or 4 carbon atoms, and LPG containing propane and butanes as main components can also be used.

On the other hand, the foaming agent E may be any foaming agent that can be used for foaming by the froth method, and may be any foaming agent that becomes a gas at room temperature (23° C.) and normal pressure (1 atm), preferably under normal pressure. It has a boiling point of less than 0°C. The foaming agent E is not particularly limited, but hydrofluoroolefin (HFO), carbon dioxide and the like can be mentioned. In the froth method, foaming agent E, which is gaseous at normal temperature and pressure, is mixed with a foam raw material such as a liquid (one liquid) containing polyol to foam. The liquid containing the polyol may contain a foaming agent (internal foaming agent) in advance. In such a case, the foaming agent E functions as a foaming aid for improving foamability and workability. have

Carbon dioxide is preferably used as the blowing agent E in the present invention. Carbon dioxide can be mixed with the liquid L1 in a liquid state by pressurization, which will be described later, thereby improving the mixing property with the liquid L1. Also, the use of carbon dioxide reduces the environmental load. However, carbon dioxide may be mixed with liquid L1 in a supercritical or subcritical state.
When carbon dioxide is used as the blowing agent E, carbon dioxide may be used alone, or a mixed gas of hydrofluoroolefin (HFO) and carbon dioxide may be used.

(Blowing agent addition device)
The blowing agent addition device 10 will be described in more detail below.
The foaming agent addition device 10 includes a liquid channel pressure gauge 31, a foaming agent container 11, a foaming agent channel 12, a foaming agent pressure pump 80, a foaming agent channel pressure gauge 90, an on-off valve 50, It includes a flow rate adjustment mechanism 60 and a control section 51 . The foaming agent addition device 10 is a device for adding the foaming agent E to the liquid L flowing through the liquid channel 30 .

A liquid pump 40 is connected to the liquid channel 30 , and the liquid L<b>1 filled in a container (not shown) such as a drum can is supplied to the liquid channel 30 by the liquid pump 40 and sent out.
Liquid pump 40 may be positive displacement or non-positive displacement, but is preferably a positive displacement pump. The positive displacement pump may be either a reciprocating pump or a rotary pump, but a reciprocating pump such as a syringe pump having a sealing mechanism on the driving part side or a plunger pump having a sealing mechanism on the cylinder side is preferable. Further, the positive displacement type may be a variable capacity type or a constant capacity type.
Depending on the type of pump, the liquid pump 40 repeatedly discharges the fluid by periodically driving various drive units such as cylinders, gears, vanes, and plungers by rotating or linear motion. For example, in a syringe pump, the cylinder makes linear motion repeatedly between the bottom dead center and the top dead center.

The liquid L1 flowing through the liquid flow path 30 is flowed while being pressurized to the discharge pressure. A liquid channel pressure gauge 31 is connected to the liquid channel 30 , and the liquid pressure LP of the liquid L<b>1 flowing through the liquid channel 30 is measured by the liquid channel pressure gauge 31 . The liquid pressure LP of the liquid L1 flowing through the liquid flow path 30 is preferably 5 to 10 MPa from the viewpoint of work stability. The liquid channel pressure gauge 31 transmits the measured liquid pressure LP to the controller 51 .

The foaming agent container 11 accommodates the foaming agent E. A pressure-resistant container is used as the foaming agent container 11, and for example, a known gas cylinder may be used. The foaming agent container 11 preferably stores the foaming agent E in a pressurized state. Further, the foaming agent container 11 may be provided with a heater (not shown). By heating with the heater, the internal pressure of the foaming agent container 11 is increased, thereby causing the heating by the foaming agent pressure pump 80. The burden of pressure can be reduced, and the foaming agent E can be easily delivered to the foam channel 12 in a state of being pressurized to a high pressure.

The foaming agent flow path 12 is a path for supplying the foaming agent E from the foaming agent container 11 to the liquid flow path 30 as described above. The foaming agent channel 12 may include a channel cooling device (not shown) composed of coolant or the like, thereby cooling the foaming agent E flowing through the foaming agent channel 12 . By cooling the foaming agent E in the foaming agent flow path 12, the foaming agent E is less likely to be vaporized, and can be easily mixed with the liquid L in a liquid state. The temperature inside the foaming agent channel 12 is preferably maintained in the range of -20 to 20°C.

A foaming agent channel pressure gauge 90 is provided in the foaming agent channel 12 . The foaming agent channel pressure gauge 90 measures the foaming agent pressure EP of the foaming agent E flowing through the foaming agent channel 12 . The foaming agent flow path pressure gauge 90 transmits the measured foaming agent pressure EP to the controller 51 .

A foaming agent pressure pump 80 is provided in the foaming agent channel 12 . The foaming agent pressurizing pump 80 is connected to the control unit 51 and provided upstream of the on-off valve 50 in the foaming agent flow path 12 . The foaming agent pressure pump 80 pressurizes the foaming agent pressure EP in the foaming agent channel 12 to a predetermined pressure higher than the liquid pressure LP of the liquid L1 flowing through the liquid channel 30 .
Specifically, the foaming agent pressure pump 80 pressurizes so that the foaming agent pressure EP is higher than the liquid pressure LP by a predetermined value. Here, the predetermined high pressure refers to a value set according to the type, properties, amount, etc. of the foaming agent E and the liquid L1 to be used, and can be set as appropriate. The value set as the predetermined high pressure is set such that the foaming agent pressure EP is higher than the liquid pressure LP by 0.05 to 5.00 MPa, for example.
The foaming agent pressurizing pump 80 can pressurize and supply the foaming agent E at a stable pressure from the viewpoint of being able to supply the foaming agent E to the liquid flow path 30 at a constant pressure via the on-off valve 50. A pump is preferable, a pump that continuously pressurizes the foaming agent is more preferable, and an axial pump or a gear pump is particularly preferable.

The foaming agent pressurizing pump 80 may be controlled by the controller 51 . The control unit 51 compares the liquid pressure LP received from the liquid flow path pressure gauge 31 and the foaming agent pressure EP received from the foaming agent flow path pressure gauge 90, and foams the foaming agent E flowing through the foaming agent flow path 12. The foaming agent pressurizing pump 80 is controlled so that the agent pressure EP is higher than the pressure LP of the liquid L1 flowing through the liquid flow path 30 . Further, when the foaming agent pressure EP reaches a specified value, the control unit 51 closes the flow rate adjustment mechanism 60 as will be described later. It is preferable to control so as to stop the supply. The control unit 51 may re-drive the stopped foaming agent pressurizing pump 80 at the timing when the flow rate adjusting mechanism 60 is opened.
As described above, by controlling the foaming agent pressure EP of the foaming agent E, it is possible to stably supply the foaming agent E to the on-off valve 50 provided on the downstream side.

A flow rate adjusting mechanism 60 is provided in the foaming agent channel 12 . In one embodiment, as shown in FIG. 1, the flow rate adjusting mechanism 60 may be provided in the foaming agent flow path 12 upstream of the on-off valve 50 and downstream of the foaming agent pressurizing pump 80. . The flow rate adjusting mechanism 60 adjusts the flow rate of the foaming agent E in the foaming agent channel 12 . The flow rate adjusting mechanism 60 can be a second on-off valve that controls the flow rate of the foaming agent E flowing in the foaming agent flow path 12 on the upstream side of the on-off valve 50 by opening and closing. The flow rate adjustment mechanism 60 suppresses excess foaming agent E flowing through the foaming agent channel 12 by opening the second on-off valve, and the foaming agent E is supplied to the liquid L1 flowing through the liquid channel 30. provide a stable supply. On the other hand, the flow rate adjustment mechanism 60 stops the supply of the foaming agent E toward the on-off valve 50 by closing the second on-off valve. The second on-off valve is composed of, for example, an electromagnetic valve.

An on-off valve 50 is provided downstream of the foaming agent pressure pump 80 and the flow rate adjusting mechanism 60 in the foaming agent flow path 12 . The on-off valve 50 controls the connection between the foaming agent channel 12 and the liquid channel 30 by opening and closing, and controls the addition of the foaming agent E to the liquid L1 by opening and closing. The on-off valve 50 is opened to supply the foaming agent E flowing through the foaming agent channel 12 to the liquid L1. On the other hand, the on-off valve 50 is closed to stop the supply of the foaming agent E to the liquid L1. The on-off valve 50 is composed of, for example, an electromagnetic valve.

A control unit 51 that controls the opening or closing of the flow rate adjusting mechanism 60 and the opening or closing of the on-off valve 50 is connected to the flow rate adjusting mechanism 60 and the opening/closing valve 50 . The control unit 51 receives the foaming agent pressure EP from the foaming agent channel pressure gauge 90 and the liquid pressure LP from the liquid channel pressure gauge 31, and controls the flow rate adjustment mechanism according to the received foaming agent pressure EP and liquid pressure LP. Control for adjusting the flow rate of the foaming agent E flowing through the foaming agent channel 12 is performed by the (second on-off valve) 60 and the on-off valve 50 . The control unit 51 performs control to open the on-off valve 50 when the foaming agent pressure EP is higher than the liquid pressure LP. Further, the control unit 51 controls the flow rate adjustment mechanism 60 as well as the control of the on-off valve 50 .

Specifically, in the initial operation, the on-off valve 50 is closed and the flow control mechanism 60 is opened, and the foaming agent pressure pump 80 is driven to increase the foaming agent pressure EP. When the unit 51 detects that the foaming agent pressure EP has risen to a specified value, the control unit 51 sends a control signal to the flow rate adjustment mechanism 60 and the on-off valve 50 . Based on the control signal, the flow control mechanism 60 is closed and the on-off valve 50 is opened to supply the foaming agent E to the liquid flow path 30 . Then, after the control to open the on-off valve 50 is performed, the on-off valve 50 is closed when a predetermined time elapses. After that, after opening the flow rate control mechanism 60, the foaming agent pressure EP is increased to a specified value by driving the foaming agent pressurizing pump 80, and then the above operation is repeated. The specified value is a value set such that the foaming agent pressure EP is higher than the liquid pressure LP by the above-described predetermined value pressure.
With the above control, the foaming agent E is supplied to the liquid channel 30 at a pressure higher than the liquid pressure LP for a predetermined time, so that a certain amount of the foaming agent E is supplied to the liquid channel 30. can do.
Further, by providing the flow rate adjusting mechanism 60 and performing the above control, the foaming agent container 11 and the foaming agent pressurizing pump 80 are prevented from being directly connected to the liquid flow path 30. It is possible to prevent the foaming agent E pressurized more than necessary in the foaming agent container 11 and the foaming agent channel 12 from being excessively supplied to the liquid channel 30 .

In addition, the control unit 51 further receives the liquid pressure LP of the liquid L1 flowing through the liquid channel 30 measured by the liquid channel pressure gauge 31, and when the liquid pressure LP is lower than a predetermined value, the on-off valve 50 may be controlled so as not to open the valve. By such control of the control unit 51, the on-off valve 50 is not opened when the liquid pressure LP is lower than a predetermined value, so that the addition of the foaming agent E when the amount of the liquid L1 flowing through the liquid flow path 30 is small. can be prevented. Examples of cases where the liquid pressure LP is lower than a predetermined value include when the foaming agent addition device 10 is started, when it is stopped, and when the liquid flow path 30 is clogged. The predetermined value of the liquid pressure LP is preferably set to a value lower than the vibration of the pulsation of the liquid pump 40, and may be set to 3 MPa, for example.

The amount of the foaming agent E supplied to the liquid L1 flowing through the liquid flow path 30 is preferably 0.05 to 5.0%, more preferably 0.1 to 4%, in terms of the volume ratio of the foaming agent E added to the liquid L1. 0.5% is more preferred, and 0.15 to 4.0% is even more preferred. By setting the supply amount of the blowing agent E within the above range, it becomes possible to contain an appropriate amount of the blowing agent in the polyol or the like, and the polyurethane foam can be appropriately foamed. The amount of the blowing agent E supplied to the liquid L1 flowing through the liquid flow path 30 is preferably adjusted according to the blowing agent E to be used. and when the foaming agent E is a mixed gas of hydrofluoroolefin and carbon dioxide, it is preferably 0.4 to 3.5%.

(foaming machine for spraying)
As shown in FIG. 2, the blowing foaming machine 1 is provided with the foaming agent addition device 10 described above. The foam blowing machine 1 in this embodiment is a device for forming polyurethane foam. However, in the present invention, the spray foaming machine is not limited to a device for forming polyurethane foam, and may be a device for forming other foams. Polyurethane foams are preferably rigid polyurethane foams as described above. The blowing foaming machine 1 is an on-site blowing foaming machine, and is a device that is brought to a construction site where polyurethane foam is to be applied and forms polyurethane foam at the construction site.

In addition to the foaming agent adding device 10, the blowing foaming machine 1 further includes the liquid flow path 30 (hereinafter also referred to as the first liquid flow path 30) and the liquid pump 40 (hereinafter also referred to as the first liquid pump 40). ). The blowing foaming machine 1 also includes a second liquid channel 32 through which a liquid L2 different from the liquid L1 flows, and a liquid pump 42 (hereinafter referred to as a second 2 liquid pumps 42). The first and second liquid pumps 40, 42 are connected to a liquid container (not shown) such as a drum, and pump the liquids L1, L2 sucked from the liquid container into the first and second liquid flow paths 30, 32, respectively. send to

Polyurethane foam can be formed by, as described above, mixing one liquid containing polyol and two liquids containing polyisocyanate, followed by foaming and curing. The liquid L1 flowing through the first liquid channel 30 is one of liquid 1 and liquid 2, and the liquid L2 flowing through the second liquid channel 32 is the other of liquid 1 and liquid 2. However, it is preferable that the liquid L1 is one liquid containing a polyol and the liquid L2 is a two liquid containing a polyisocyanate.

The spray foaming machine 1 includes a spray gun 70 . The spray gun 70 includes a discharge section 70A and a mixing section 70B. In the mixing section 70B, the first and second liquid flow paths 30, 35 are merged. Liquid 1 and liquid 2 flowing through the first and second liquid flow paths 30 and 32 are mixed in the mixing section 70B, and the mixture (urethane resin composition) is ejected from the discharge section 70A. At this time, the urethane resin composition is preferably sprayed onto a surface to be applied, such as a roof, wall surface, or floor of a building or structure. The injected urethane resin composition expands and hardens to form a polyurethane foam. Polyurethane foams are used, for example, as thermal insulation.

In the spray foaming machine 1 described above, the liquid L1 obtained by appropriately mixing the foaming agent E using the foaming agent addition device 10 is used as a raw material for the polyurethane foam. can be formed.

[Method of adding foaming agent]
A method of adding the foaming agent E to the liquid L1 in the foaming agent addition device 10 according to the present embodiment will be described in detail with reference to the flow chart of FIG. In the following, the pressure, temperature, etc. will be described as a specific example in which the foaming agent E is carbon dioxide. You can set the temperature etc. Note that the flowchart of FIG. 3 is a diagram for explaining the method of adding a foaming agent, and the method of adding a foaming agent does not proceed in the order of steps shown in FIG.

In step S<b>1 , the foaming agent E contained in the foaming agent container 11 is supplied to the foaming agent flow path 12 . The temperature of the foaming agent E supplied to the foaming agent channel 12 is preferably maintained within the range of -20 to 20°C. Further, the foaming agent pressure EP toward the on-off valve 50 inside the foaming agent channel 12 is preferably adjusted to be in the range of 5 to 12 MPa.

In step S<b>2 , the foaming agent pressure EP of the foaming agent E flowing through the foaming agent channel 12 is measured by the foaming agent channel pressure gauge 90 . The obtained foaming agent pressure EP is sent to the controller 51 .

Further, in step S3, the liquid pressure LP of the liquid L1 flowing through the liquid channel 30 is measured by the liquid channel pressure gauge 31. FIG. The obtained liquid pressure LP is sent to the controller 51 .

In step S<b>4 , the foaming agent pressure EP in the foaming agent flow path 12 is increased to a predetermined pressure by the foaming agent pressure pump 80 . Specifically, the control unit 51 measures the liquid pressure LP of the liquid L1 flowing through the liquid flow channel 30 measured by the liquid flow channel pressure gauge 31, and the foaming agent flow channel 12 measured by the foaming agent flow channel pressure gauge 90. Receive blowing agent pressure EP of blowing agent E. After receiving the liquid pressure LP and the foaming agent pressure EP, the controller 51 compares the liquid pressure LP and the foaming agent pressure EP, and presses the foaming agent so that the foaming agent pressure EP is higher than the liquid pressure LP by a predetermined value or more. Controls pressure pump 80 .

Further, in step S<b>5 , the flow rate adjustment mechanism 60 provided in the upstream foaming agent channel 12 of the on-off valve 50 adjusts the flow rate of the foaming agent E flowing in the upstream foaming agent channel 12 . Specifically, by opening or closing the flow rate adjusting mechanism 60 , the flow rate of the foaming agent E flowing in the foaming agent flow path 12 on the upstream side of the on-off valve 50 is controlled.

In step S6, addition of the foaming agent E to the liquid L1 is controlled by opening and closing the on-off valve 50. FIG.
In the step of controlling the addition of the foaming agent E by opening and closing the on-off valve 50, the controller 51 that receives the liquid pressure LP and the foaming agent pressure EP compares the liquid pressure LP and the foaming agent pressure EP, and determines that the foaming agent pressure EP is When the liquid pressure LP is higher than the liquid pressure LP by a predetermined value or more, the on-off valve 50 is controlled to open.

[Foam manufacturing method]
A foam can be formed by using the foaming agent addition device 10 according to the first embodiment of the present invention. The method for producing a polyurethane foam according to the present embodiment includes the steps S1 to S6 described above, and furthermore, the foaming agent addition device 10 adds the foaming agent E to the liquid L1 flowing through the liquid flow path 30. It includes a step of discharging a mixture prepared by mixing L1 and liquid L2 with the spray foaming machine 1 from a discharge device. Specifically, the following steps (1) to (7) are included.
(1) Step of supplying the foaming agent E contained in the foaming agent container 11 to the foaming agent channel 12 (2) The foaming agent pressure EP of the foaming agent E flowing through the foaming agent channel 12 is (3) measuring the liquid pressure LP of the liquid L1 flowing through the liquid channel 30 with the liquid channel pressure gauge 31; (5) Adjusting the flow rate of the foaming agent E by the flow rate adjusting mechanism 60 provided in the foaming agent flow path 12 upstream of the on-off valve 50 (6) The foaming agent for the liquid L1 Step (7) for controlling the addition of E by opening and closing the on-off valve 50: The liquid L1 obtained by adding the foaming agent E to the liquid L1 flowing through the liquid flow path 30 in the foaming agent adding device 10, and the liquid L2 for spraying. A step of discharging the mixture prepared by mixing in the foaming machine 1 from the discharging device

As described above, in the present embodiment, by providing the flow rate adjustment mechanism 60 , the foaming agent E can be stably supplied to the liquid L1 flowing through the liquid flow path 30 . For example, even when the foaming agent pressure EP is high at high temperatures such as in summer, the flow rate adjustment mechanism 60 can prevent excessive addition of the foaming agent E to the liquid L1. Further, since the foaming agent E is supplied to the liquid channel 30 for a predetermined time at a pressure higher than the liquid pressure LP, a certain amount of the foaming agent E can be supplied to the liquid channel 30. can.
Although the flow rate adjusting mechanism 60 in the present embodiment has been described as being the second on-off valve, other mechanisms may be used as long as the flow rate of the foaming agent E can be adjusted. Even if the flow rate adjusting mechanism 60 is not the second on-off valve, the foaming agent E can be prevented from being excessively supplied to the liquid channel 30 if the flow rate can be adjusted by the flow rate adjusting mechanism 60 .
When a valve other than the second on-off valve is used as the flow rate adjustment mechanism 60, for example, instead of closing the flow rate adjustment mechanism 60 in the above configuration, the flow rate of the foaming agent is relatively reduced by the first amount. Instead of opening the flow rate adjusting mechanism 60, the flow rate of the foaming agent is preferably adjusted to a second amount that is greater than the first amount.

In the above description, as shown in FIG. 1, the flow rate adjusting mechanism 60 is upstream of the on-off valve 50, and is provided in the foaming agent flow path 12 downstream of the foaming agent pressurizing pump 80. However, as shown in FIG. 4 , the flow rate adjusting mechanism 60 may be provided in the foaming agent flow path 12 upstream of the on-off valve 50 and upstream of the foaming agent pressurizing pump 80 .
In this configuration as well, the foaming agent container 11 is prevented from being directly connected to the liquid flow path 30, so that the foaming agent container 11, the foaming agent flow path 12, and the like at high temperatures such as in the summertime are heated to an excessively high pressure. It is possible to prevent the agent E from being excessively supplied to the liquid channel 30 .
However, by having the configuration shown in FIG. 1, the flow rate adjusting mechanism 60 is located downstream of the foaming agent pressurizing pump 80 and closer to the on-off valve 50, so that stable control is possible.

[Second embodiment]
Next, a second embodiment of the invention will be described in detail. The second embodiment is different from the first embodiment in that the liquid pump 40 is provided with a pump driving detector 41, as shown in FIGS. Differences between the second embodiment and the first embodiment will be described below. In addition, parts whose description is omitted are the same as those in the first embodiment. Also, in the following description, members having the same configurations as those of the first embodiment are denoted by the same reference numerals.

The liquid pump 40 according to the present embodiment is provided with a pump drive detector 41 . The pump driving detector 41 detects driving of the liquid pump 40 . The pump driving detection unit 41 transmits pump driving information DI regarding the detected driving of the liquid pump 40 to the control unit 51 .
The liquid pump 40 periodically drives the driving section by reciprocating or rotating motion, and the pump driving detection section 41 can detect to which position the driving section is driven in the cycle. For example, a reciprocating pump such as a syringe pump reciprocates between the bottom dead center and the top dead center. detectable. In the case of a rotary pump as well, it is sufficient if it is possible to detect to which position in the rotary motion the driving part is driven.
A sensor is used as the pump drive detector 41 . Specific sensors include a laser distance sensor that measures the driving position of the driving part of the liquid pump 40 as a distance, and a sensor that detects when the driving part of the liquid pump 40 reaches a certain position (for example, top dead center or bottom dead center). A position sensor for detecting that the

The control unit 51 receives the pump drive information DI of the liquid pump 40 from the pump drive detection unit 41, and controls the on-off valve 50 and the flow rate adjustment according to the drive status of the liquid pump 40 in addition to the foaming agent pressure EP and the liquid pressure LP. Control to open or close the mechanism 60 is performed. Specifically, when the foaming agent pressure EP rises to a specified value and the drive position of the liquid pump 40 reaches a predetermined position (predetermined position), control is performed to open the on-off valve 50, At the same time, control is performed to close the flow rate adjustment mechanism 60 . By opening the on-off valve 50, a certain amount of the foaming agent E is supplied to the liquid flow path 30 as in the first embodiment.
The liquid pump 40 is driven periodically as described above. When the opening/closing valve 50 opens when the position (driving position) of the driving portion of the liquid pump 40 reaches a predetermined position, at the same timing of the cycle, The foaming agent E will be supplied to the liquid L1. Here, since the liquid pump 40 supplies the liquid L to the liquid channel 30 with substantially the same behavior (that is, substantially the same pressure and the same flow rate) at the same timing of the cycle, a predetermined amount (that is, a constant amount) is supplied at that timing. ) is supplied to the liquid channel 30, the supply of the foaming agent E to the liquid L1 is stabilized.
That is, in the present embodiment, by controlling the on-off valve 50 to open when the driving portion of the liquid pump 40 reaches a predetermined position (predetermined position), the foaming agent E is stably supplied to the liquid L1. becomes possible.
Further, by controlling the on-off valve 50 to be opened when the predetermined position is reached and then closed, the opening and closing of the on-off valve 50 are repeated in the same manner as in the first embodiment. Also, the flow rate adjustment mechanism (second on-off valve) 60 may be controlled to be repeatedly closed and opened, as in the first embodiment.
That is, when it is detected that the foaming agent pressure EP has risen to a specified value and the pump driving information DI indicating that the driving position is to be driven to a predetermined position is received, a control signal is sent from the control unit 51 to the flow rate adjusting mechanism 60 and the opening/closing mechanism. delivered to valve 50; Based on the control signal, the flow control mechanism 60 may be closed and the on-off valve 50 may be opened to supply the foaming agent E to the liquid flow path 30 . After that, control may be performed in the same manner as in the first embodiment.

The predetermined position is not particularly limited, but if the liquid pump 40 is a reciprocating pump such as a syringe pump, it may be the top dead center, the bottom dead center, or a specific position therebetween. It is preferably either dead center. After reaching the top dead center or the bottom dead center, the pressure of the liquid L1 supplied to the liquid flow path 30 decreases. Therefore, when the predetermined position is the top dead center or the bottom dead center, the foaming agent E is supplied at the timing when the pressure is lowered, and the foaming agent E is easily mixed with the liquid L1.
Further, in the reciprocating pump, the predetermined position need not be one during one cycle in which the drive unit reaches from the top dead center to the bottom dead center and then from the bottom dead center to the top dead center. , two or more positions, and for example, both the top dead center and the bottom dead center may be set at predetermined positions.
In addition, in the case of a rotary pump, the predetermined position is, for example, n°, which is a specific position within the rotation cycle (0 to 360°) (where n ) is set at a predetermined position.

The control unit 51 may control the drive unit of the liquid pump 40 to open the on-off valve 50 once every cycle, or control the on-off valve 50 to open once every two cycles. Alternatively, the on-off valve 50 may be controlled to open once every n cycles (where n is an integer equal to or greater than 3). Further, the control unit 51 may control the drive unit of the liquid pump 40 to open the on-off valve 50 a plurality of times within one cycle, for example, control the valve to open once every half cycle. may
It should be noted that opening the valve once per cycle means, for example, when the top dead center is set at a predetermined position, the valve is opened each time the top dead center is reached. The same applies to the bottom dead center.
Further, for example, when a specific position between the top dead center and the bottom dead center is set as the predetermined position, it is necessary to open the on-off valve 50 in any case when the drive unit reaches the predetermined position. Instead, it is preferable to control the valve to open either when the drive unit moves from the top dead center to the bottom dead center or from the bottom dead center to the top dead center.
Furthermore, in a double-acting type having a plurality of drive units (for example, a double-acting plunger pump), the on-off valve may be controlled based on the drive of any one drive unit, or may be controlled based on the drive of a plurality of drive units. may be controlled based on When controlled based on the driving of a plurality of drive units, for example, the valve may be opened each time the drive unit of each drive unit is arranged at a predetermined position.

The flow chart of FIG. 7 shows a method of adding the foaming agent E to the liquid L1 in the foaming agent addition device 10 of the present embodiment.
The flow chart of FIG. 7 further includes a step of detecting the drive of the liquid pump 40 by the pump drive detector 41 (step S10).
In step S10, the step of detecting the drive of the liquid pump 40 by the pump drive detection unit 41 is performed by detecting the drive position of the drive unit of the liquid pump 40 for pressurizing the liquid L1 flowing through the liquid flow path 30 by the pump drive detection unit 41. It detects and obtains pump driving information DI regarding the driving of the detected liquid pump 40 . The pump driving detection unit 41 is preferably a laser application sensor capable of continuously measuring the driving position of the driving unit of the liquid pump 40 . The obtained pump driving information DI is transmitted to the control section 51 .
Then, in the step of controlling the addition of the foaming agent E by opening and closing the on-off valve 50 (step S6), the control unit 51 operates the on-off valve 50 according to the drive status of the liquid pump 40 detected by the pump drive detection unit 41. Control to open the valve is also performed. Specifically, the control unit 51 detects that the foaming agent pressure EP has risen to a specified value, receives the pump drive information DI of the liquid pump 40 from the pump drive detection unit 41, and It is preferable to perform control to open the on-off valve 50 when the drive position reaches a predetermined position (predetermined position).

As described above, in the present embodiment, the driving state of the liquid pump 40 is detected by providing the pump driving detection unit 41 that detects driving of the liquid pump 40 , and control and do. In this way, by performing control according to the drive state of the liquid pump 40 instead of the control according to the liquid pressure in the liquid flow path 30, the liquid flow path 30 is not affected by the pulsation of the liquid pump 40. The foaming agent E can be stably supplied to the flowing liquid L1.

[Other embodiments]
The foaming agent adding device, the blowing foaming machine, the foaming agent adding method, and the foam manufacturing method shown and described in the first and second embodiments as described above are examples of the present invention. The present invention is not limited to the configuration of the embodiment, and various improvements and changes are possible without departing from the scope of the present invention, and constituent elements may be added as appropriate.
For example, as shown in FIG. 8, the foaming agent adding device 10 includes a check valve 52 between a foaming agent pressurizing pump 80 and an on-off valve 50 for preventing backflow of the foaming agent E flowing through the foaming agent flow path 12. can be configured to include

REFERENCE SIGNS LIST 1 foaming machine for spraying 10 foaming agent addition device 11 foaming agent container 12 foaming agent channel 30 liquid channel (first liquid channel)
31 Liquid channel pressure gauge 32 Second liquid channel 40 Liquid pump (first liquid pump)
41 pump drive detector 42 liquid pump (second liquid pump)
50 On-off valve 51 Control unit 52 Check valve 60 Flow rate adjustment mechanism 70 Spray gun 70A Discharge unit 70B Mixing unit 80 Foaming agent pressurizing pump 90 Foaming agent flow path pressure gauge E Foaming agent L1, L2 Liquid

Claims (13)

A foaming agent addition device for adding a foaming agent to a liquid supplied by a liquid pump and flowing through a liquid channel,
a liquid channel pressure gauge for measuring the liquid pressure of the liquid flowing through the liquid channel;
a foaming agent container containing the foaming agent;
a foaming agent channel through which the foaming agent supplied from the foaming agent container flows;
a foaming agent pressurizing pump that pressurizes the foaming agent pressure in the foaming agent channel to a predetermined pressure;
a blowing agent channel pressure gauge for measuring the blowing agent pressure of the blowing agent flowing through the blowing agent channel;
an on-off valve that controls connection between the foaming agent channel and the liquid channel by opening and closing, and controls addition of the foaming agent to the liquid by opening and closing;
a flow rate adjustment mechanism that adjusts the flow rate of the foaming agent to the foaming agent flow path upstream of the on-off valve;
a controller that opens the on-off valve when the foaming agent pressure measured by the foaming agent channel pressure gauge is higher than the liquid pressure measured by the liquid channel pressure gauge. agent addition device. The foaming agent addition device according to claim 1, wherein the flow rate adjustment mechanism is a second on-off valve that controls the flow rate of the foaming agent flowing through the foaming agent flow path on the upstream side of the on-off valve. 3. The foaming agent addition device according to claim 1, wherein said foaming agent pressurizing pump pressurizes said foaming agent so that said foaming agent pressure is higher than said liquid pressure by a predetermined value. The foaming agent according to any one of claims 1 to 3, wherein the control unit controls to close the on-off valve after a predetermined time has elapsed after controlling to open the on-off valve. Addition device. The foaming agent addition device according to any one of claims 1 to 4, wherein the foaming agent pressurizing pump is a pump that continuously pressurizes the foaming agent. The foaming agent addition device according to any one of claims 1 to 5, wherein the foaming agent pressure pump is either an axial pump or a gear pump. further comprising a pump drive detection unit that detects drive of the liquid pump;
7. The apparatus according to any one of claims 1 to 6, wherein when the pump drive detection unit detects that the liquid pump reaches the top dead center or the bottom dead center, the control unit controls opening of the on-off valve. A blowing agent addition device according to any one of the preceding items. The blowing agent addition device according to any one of claims 1 to 7, wherein the liquid contains polyol or polyisocyanate. The foaming agent addition device according to any one of claims 1 to 8, wherein the liquid contains a filler. The blowing agent addition device according to any one of claims 1 to 9, wherein the blowing agent contains carbon dioxide. A spray foaming machine comprising the foaming agent addition device according to any one of claims 1 to 10. A blowing agent addition method for adding a blowing agent to a liquid supplied by a liquid pump and flowing through a liquid channel, comprising:
supplying the foaming agent contained in the foaming agent container to the foaming agent channel;
measuring the blowing agent pressure of the blowing agent flowing through the blowing agent channel with a blowing agent channel pressure gauge;
measuring the liquid pressure of the liquid flowing through the liquid channel with a liquid channel pressure gauge;
a step of increasing the pressure of the foaming agent in the foaming agent channel to a predetermined pressure with a foaming agent pressure pump;
a step of controlling connection between the foaming agent channel and the liquid channel by opening and closing an on-off valve, and controlling addition of the foaming agent to the liquid by opening and closing the on-off valve;
adjusting the flow rate of the foaming agent by a flow rate adjusting mechanism provided in the foaming agent flow path on the upstream side of the on-off valve,
when the foaming agent pressure measured by the foaming agent flow path pressure gauge is higher than the liquid pressure measured by the liquid flow path pressure gauge in the step of controlling the addition of the foaming agent by opening and closing an on-off valve; (2) a method of adding a foaming agent, wherein a control unit controls opening of the on-off valve; A method for producing a foam, comprising adding a foaming agent to a liquid flowing through a liquid channel by the method for adding a foaming agent according to claim 12 .

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