Premixing system for gun head of foaming machine

Abstract

The utility model discloses a premixing system for a gun head of a foaming machine. The premixing system comprises a first material supply device, a second material supply device, a mixing gun head and an emulsifying device, each of the first material supply device and the second material supply device comprises a material tank, a feeding pump and a first pipeline, and the two material tanks are connected with two material inlets of the mixing gun head through the first pipelines and the feeding pumps respectively; wherein one material tank is provided with a pressurizing device, the pressurizing device is used for pressurizing the material tank, the emulsifying device comprises emulsifying equipment, a first circulating pump and a second circulating pump, and the emulsifying equipment is respectively connected with an inlet and an outlet of the material tank provided with the pressurizing device through the first circulating pump and the second circulating pump. The gas-phase material is prevented from escaping through the supercharging device, meanwhile, re-emulsification can be conveniently achieved through the dispersing device, and the stability of the material in the using process is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of polyurethane production equipment, and particularly relates to a pre-mixing system for a foaming machine gun head. Background Art

[0002] Rigid polyurethane foam is an excellent heat-insulating material, usually prepared by reacting a polyol component (also known as white material) with an isocyanate component (also known as black material). In order to further improve the energy-saving and consumption-reducing effect of rigid polyurethane foam, the polyol component or / and the isocyanate component is usually emulsified. Different from narrow emulsification, emulsification in this field not only includes homogeneous dispersion between liquid-liquid phases, but also includes homogeneous dispersion between gas-liquid phases. For example, Chinese Patent CN206953388U discloses a simple large-flow white material emulsifying and foaming device for polyurethane foaming, which adopts a scheme of introducing gas and white material into a mixing tube for emulsification. Chinese Patent CN103748149A discloses emulsions and their uses in the preparation of isocyanate-based foams, adopting a liquid-liquid emulsification method, that is, a physical blowing agent is dispersed in a polyol mixture in the form of fine liquid droplets to achieve the effect of optimizing heat insulation.

[0003] The emulsified polyol component or / and isocyanate component are mixed in a high-pressure mixing injection gun head and then injected into the box to be foamed, and polyurethane foam is obtained after curing. In order to ensure that the performance of rigid polyurethane foam is not negatively affected, emulsifiers are usually not added additionally during the emulsification process, so the stability of the obtained mixed liquid is poor, and liquid-liquid stratification, gas-liquid separation, etc. are likely to occur. Especially for the homogeneous dispersion between gas-liquid phases, the obtained emulsion is less stable and is prone to two-phase separation under the influence of factors such as the environment. In addition, during the production preparation and the intermittent period of the production process, the mixed liquid after emulsification needs to undergo a long storage process, thus further increasing the risk of two-phase separation.

[0004] For example, Chinese Patent CN112457461A discloses a polyurethane foaming system and a foaming method, including a premixing station and a foaming machine platform; the premixed black material and the premixed white material are first premixed at the premixing station, then transported to the material storage tank on the foaming machine platform, and finally foamed by injecting the white material and the black material in the front-of-machine white material tank and the front-of-machine black material tank into the gun head. Since this system does not have an emulsification function, two-phase separation will occur during the storage of the premixed material in the tank on the foaming machine platform, reducing the production quality of polyurethane. Summary of the Utility Model

[0005] To solve the above technical problems, the utility model provides a pre-mixing system for a foaming machine gun head used in polyurethane production.

[0006] The technical solution adopted by the utility model is:

[0007] A pre-mixing system for a foaming machine head includes a first material supply device, a second material supply device, a mixing gun head, and an emulsifying device; both the first material supply device and the second material supply device include a material tank, a feed pump, and a first pipeline. The two material tanks are respectively connected to the two material inlets of the mixing gun head through the first pipeline and the feed pump; a pressurizing device is provided on one of the material tanks, and the pressurizing device is used to pressurize the material tank. The emulsifying device includes an emulsifying equipment, a first circulation pump, and a second circulation pump. The emulsifying equipment is respectively connected to the inlet and outlet of the material tank provided with the pressurizing device through the first circulation pump and the second circulation pump.

[0008] By providing the emulsifying device, the polyol component or the isocyanate component can be subjected to circulating emulsification treatment, thereby improving the stability and storage time of the emulsified liquid in the material tank. By providing the pressurizing device, the escape of low-boiling components from the raw material system can be reduced. In addition, appropriate pressurization can also liquefy the gas-phase components and make them re-enter the material for secondary homogeneous dispersion or emulsification.

[0009] The emulsifying equipment is a conventional equipment in the art, as long as it can achieve homogeneous dispersion between compatible or incompatible liquid-liquid phases, gas-liquid phases, and solid-liquid phases. It can be an open structure or a closed structure. In order to ensure accurate metering of the mixing between the gas-liquid phases, a closed structure is preferably used, such as a pipeline emulsifier or a stirring tank with a hollow impeller, etc.

[0010] Furthermore, pressurizing devices are provided on both material tanks, and there are two sets of emulsifying devices, which are respectively connected to the two material tanks. The polyol component and the isocyanate component can both be subjected to emulsification treatment.

[0011] Furthermore, the pressurizing device includes a pressurizing pipeline and a control valve provided on the pressurizing pipeline. One end of the pressurizing pipeline is connected to the material tank, and the other end is used to connect to a gas source. The end of the pressurizing pipeline for connecting to the gas source can be connected to a compression pump or directly connected to a pressurized gas tank. The gas source can be compressed air or an inert gas (such as nitrogen, etc.).

[0012] Furthermore, the material tank provided with the pressurizing device is connected to the feed pump through a stop valve. The setting of the stop valve can prevent the material from entering the first pipeline during the emulsification preparation stage.

[0013] Furthermore, the emulsifying device also includes a hydrometer and a volumetric flowmeter. The hydrometer and the volumetric flowmeter are provided on the connecting pipeline between the emulsifying equipment and the material tank. By monitoring the change of the mass flow rate through the hydrometer and the volumetric flowmeter, it can be inferred whether the emulsion is stable or whether the emulsification is complete, thus improving the monitoring accuracy.

[0014] Further, a filter and a flow meter are also provided on the first pipeline. The filter and the flow meter are respectively arranged on the inlet side and the outlet side of the feed pump. By setting the filter, blockage of the feed pump can be prevented, and by setting the flow meter, the feed amount can be accurately measured.

[0015] Further, both the first material supply device and the second material supply device further include a second pipeline, a third pipeline, a check valve and a reversing valve. The two material tanks are respectively connected to the two circulating material outlets of the mixing gun head through two second pipelines. The first pipeline is connected to the third pipeline through the reversing valve. The third pipeline is connected to the second pipeline through a tee. A check valve is provided on the second pipeline, and the check valve is arranged between the third pipeline and the mixing gun head.

[0016] The material tank outlet, the first pipeline, the feed pump, the reversing valve, the mixing gun head, the check valve, the second pipeline, and the material tank inlet are sequentially connected to form a high-pressure circulation pipeline. The material tank outlet, the first pipeline, the feed pump, the reversing valve, the third pipeline, the second pipeline, and the material tank inlet are sequentially connected to form a low-pressure circulation pipeline. By setting the high- and low-pressure circulation pipelines, parameters such as the temperature of the material and the pipeline pressure can reach a stable state and then continuous injection can be realized.

[0017] Further, the emulsifying device further includes a third material tank, which is used to add gas-phase, liquid-phase or solid-phase materials to the emulsifying equipment during the emulsification process. It is convenient to timely adjust the type and amount of additive, and liquid-phase, gas-phase or solid additive can be continuously added to improve the emulsification effect.

[0018] Further, the emulsifying device further includes a gas-phase conveying device, which is connected to the material tank and is used to send the gas-phase components in the material tank into the emulsifying equipment for emulsification. It can ensure that the emulsification uniformity of the material is further improved without changing the original formula system.

[0019] Further, the gas-phase conveying device includes a piston compressor. The inlet and outlet of the piston compressor are respectively connected to the material tank and the emulsifying equipment through a gas-phase conveying pipeline, and a flow regulating valve is arranged on the gas-phase conveying pipeline. The piston compressor can ensure that all gas-phase components can completely enter the emulsifying equipment. Description of the Drawings

[0020] Figure 1 It is a schematic structural diagram of Embodiment 1.

[0021] Figure 2 It is a schematic structural diagram of Embodiment 2.

[0022] Figure 3 It is a schematic structural diagram of Embodiment 3.

[0023] Figure 4 It is a schematic structural diagram of Embodiment 4. Detailed Embodiments

[0024] To make the objectives, technical solutions and advantages of the present utility model clearer, the technical solutions of the present utility model will be clearly and completely described below in conjunction with the accompanying drawings and a preferred embodiment.

[0025] Embodiment 1

[0026] Refer to Figure 1 , this embodiment provides a pre-mixing system for a No. 1 foaming machine head, including a first material supply device 1, a second material supply device 2, an emulsifying device 3 and a mixing gun head 4. The first material supply device 1 includes a first pipeline A, a first material tank 11, a first feed pump 12 and a first flow meter 13. The second material supply device 2 includes a first pipeline B, a second material tank 21, a second pressurizing component 211, a second feed pump 22, a second flow meter 23 and a second valve 24. The emulsifying device 3 includes an emulsifying equipment 31, a first circulation pump 32 and a second circulation pump 33. The mixing gun head 4 is provided with a first material inlet 41, a second material inlet 42 and a discharge port 43.

[0027] The material outlet of the first material tank 11 is sequentially connected to the first feed pump 12 and the first flow meter 13 through the first pipeline A, and the outlet end of the first flow meter 13 is connected to the first material inlet 41 of the mixing gun head 4;

[0028] The first material outlet of the second material tank 12 is sequentially connected to the second valve 24, the second feed pump 22 and the second flow meter 23 through the first pipeline B. The outlet end of the second flow meter 23 is connected to the second material inlet 42 of the mixing gun head 4. A second pressurizing component 211 is further provided on the second material tank 21, and this pressurizing component is a pipeline with a valve;

[0029] The emulsifying device 3 is a single-sided emulsifying device, which is connected to the second material supply device 2. In this embodiment, the emulsifying equipment 31 is a stirring tank with a hollow impeller. The material outlet of the stirring tank is sequentially connected to the first circulation pump 32 and the first material inlet of the second material tank through a pipeline. The second material outlet of the second material tank is sequentially connected to the second circulation pump 33 and the material inlet of the stirring tank through a pipeline, forming an emulsifying circulation pipeline.

[0030] When the mixing system of Embodiment 1 is in use:

[0031] The polyol component can be placed in the first storage tank 11, and the isocyanate component can be placed in the second storage tank 21. Close the second valve 24, connect the second pressurizing component 211 to compressed air and open the valve on the pressurizing component to increase the pressure in the second storage tank 21. Open the first circulation pump 32 and the second circulation pump 33, so that the isocyanate component enters the emulsifying device 3 through the second circulation pump 33 for emulsification, and then returns to the second storage tank 21 through the first circulation pump 32. After the circulation is stable, open the second valve 24, and at the same time start the first feed pump 12 and the second feed pump 22. The polyol component and the re-emulsified isocyanate component enter the mixing nozzle 4 at the same time, and the mixed material flows out from the discharge port 43 of the mixing nozzle.

[0032] Alternatively, the isocyanate component can be placed in the first storage tank 11, and the polyol component can be placed in the second storage tank 21. Perform the same operations as above. The isocyanate component and the re-emulsified polyol component enter the mixing nozzle 4 at the same time, and the mixed material flows out from the discharge port 43 of the mixing nozzle.

[0033] Example 2

[0034] Refer to Figure 2 This embodiment provides a pre-mixing system for a 2# foaming machine gun head, which includes a first material supply device 1, a second material supply device 2, an emulsifying device 3, and a mixing nozzle 4. The first material supply device 1 includes a first storage tank 11, a first pressurizing component 111, a first pipeline A, a second pipeline A, a third pipeline A, a first feed pump 12, a first valve 14, a first reversing valve 15, a first check valve 16, and a first tee 17. The second material supply device 2 includes a second storage tank 21, a first pipeline B, a second pipeline B, a third pipeline B, a second feed pump 22, a second reversing valve 25, a second check valve 26, and a second tee 27. The emulsifying device 3 is a single-sided emulsifying device, which is connected to the first material supply device 1 and includes an emulsifying equipment 31, a first circulation pump 32, a second circulation pump 33, and a third material conveying device. The third material conveying device includes a third storage tank 34 and a valve. The mixing nozzle 4 is provided with a first material inlet 41, a second material inlet 42, a discharge port 43, a first circulating material outlet 44, and a second circulating material outlet 45.

[0035] The first material outlet of the first storage tank 11 is sequentially connected to the first valve 14, the first feed pump 12, the first reversing valve 15, and the first material inlet 41 of the mixing nozzle 4 through the first pipeline A. The first circulating material outlet 44 of the mixing nozzle 4 is sequentially connected to the first check valve 16, the first tee 17, and the first material inlet of the first storage tank 11 through the second pipeline A, forming a high-pressure circulation loop in which the material flows out of the first storage tank, passes through the first reversing valve, the mixing nozzle, etc., and then flows back into the first storage tank.

[0036] The first material outlet of the first material tank 11 is connected to the first valve 14, the first feed pump 12, and the first reversing valve 15 through the first pipeline A. The first reversing valve 15 is connected to the first material inlet of the first material tank 11 through the third pipeline A, the first three-way pipe 17, and the second pipeline A, forming a low-pressure circulation loop in which the material flows out of the first material tank, passes through the first reversing valve 15, and then flows back into the first material tank.

[0037] The second material outlet of the first material tank 11 is successively connected to the second circulation pump 33, the emulsifying device 31, the first circulation pump 32, and the second material inlet of the first material tank 11 through pipelines, forming an emulsifying loop. At the same time, a first pressurizing component 111 is also provided on the first material tank 11, and this pressurizing component is a pipeline with a valve.

[0038] The third material tank 34 is successively connected to a valve and the emulsifying device 31 through pipelines, and is used to add gaseous, liquid, or solid materials to the emulsifying device during the emulsification process. In this embodiment, the emulsifying device 31 is a line-type emulsifier.

[0039] The first material outlet of the second material tank 21 is successively connected to the second feed pump 22, the second reversing valve 25, and the second material inlet 42 of the mixing gun head 4 through the first pipeline B. The second circulating material outlet 45 of the mixing gun head 4 is successively connected to the second one-way valve 26, the second three-way pipe 27, and the first material inlet of the second material tank 21 through the second pipeline B, forming a high-pressure circulation loop in which the material flows out of the second material tank, passes through the second reversing valve, the mixing gun head, etc., and then flows back into the second material tank.

[0040] The first material outlet of the second material tank 21 is connected to the second feed pump 22 and the second reversing valve 25 through the first pipeline B. The second reversing valve 25 is connected to the first material inlet of the second material tank 21 through the third pipeline B, the second three-way pipe 27, and the second pipeline B, forming a low-pressure circulation loop in which the material flows out of the second material tank, passes through the second reversing valve 25, and then flows back into the second material tank.

[0041] When the hybrid system of Example 2 is in use, place the polyol component in the first storage tank 11 and the isocyanate component in the second storage tank 21. Close the first valve 14, connect the first pressurizing component 111 to a nitrogen cylinder and open the valve on the pressurizing component to increase the pressure in the first storage tank 11. Open the first circulation pump 32 and the second circulation pump 33, so that the polyol component enters the emulsifying device 31 through the second circulation pump 33. At the same time, open the valve at the front end of the third storage tank 34 to transport the physical foaming agent in the gas phase placed in the third storage tank to the emulsifying device 31, so that the materials are emulsified in the emulsifying device and return to the first storage tank 11 through the first circulation pump 32. After the circulation is stable, open the first valve 14, close the high-pressure circulation outlet of the first reversing valve 15, and open the low-pressure circulation outlet, so that the emulsified polyol component undergoes low-pressure circulation. At the same time, close the high-pressure circulation outlet of the second reversing valve 25 and open the low-pressure circulation outlet, so that the isocyanate component can undergo low-pressure circulation.

[0042] After the low-pressure circulation ends, close the low-pressure circulation outlets of the first reversing valve 15 and the second reversing valve 25, and open the high-pressure circulation outlets, so that the emulsified polyol component enters the inside of the gun head through the first material inlet 41 of the mixing gun head 4, and the isocyanate component enters the inside of the gun head through the second material inlet 42 of the mixing gun head 4. The two materials are mixed in the cavity of the mixing gun head 4 and flow out of the discharge port 43 as a mixed material.

[0043] After the injection is completed, the piston in the mixing gun head 4 moves reciprocally to close the channels connecting the first material inlet 41 and the second material inlet 42 to the cavity of the mixing gun head, so that the polyol component enters through the first material inlet 41 and then flows out from the first circulating material outlet 44, and then returns to the first storage tank 11 through the first one-way valve 16 and the first three-way pipe 17. Similarly, the isocyanate component enters through the second material inlet 42 and then flows out from the second circulating material outlet 45, and then returns to the second storage tank 21 through the second one-way valve 26 and the second three-way pipe 27.

[0044] Throughout the process, the emulsification circuit is always in a working state to ensure the persistence of the emulsification effect.

[0045] Example 3

[0046] Refer to Figure 3 This example provides a pre-mixing system for a 3# foaming gun head. Compared with the pre-mixing system for a 2# foaming gun head, the difference is that filters and flow meters are added to both the first material supply device 1 and the second material supply device 2 for filtering and metering the materials; a hydrometer 36 and a volumetric flow meter 38 are added to the emulsifying device 3, and the third material conveying device is replaced with a gas-phase conveying device. The remaining components and their connection methods are the same as those of the pre-mixing system for a 2# foaming gun head.

[0047] The first filter 18 is provided between the first storage tank 11 and the first feed pump 12, the second filter 28 is provided between the second storage tank 21 and the second feed pump 22, the first flowmeter 13 is provided between the first switching valve 15 and the mixing nozzle 4, and the second flowmeter 23 is provided between the second switching valve 25 and the mixing nozzle 4.

[0048] The hydrometer 36 and the volumetric flowmeter 38 are provided between the second circulation pump 33 and the first storage tank 11, and are used for on-line monitoring of the changes in the specific gravity and mass flow rate of the material, so as to accurately judge the end point of the circulation stability and avoid energy consumption waste. The gas-phase conveying device includes a piston compressor 37 and a flow regulating valve 35. The piston compressor 37 is connected to the emulsifying device 31 and the first storage tank 11 through a gas-phase conveying pipeline, and the flow regulating valve 35 is arranged on the gas-phase conveying pipeline.

[0049] When the mixing system of this embodiment is in use:

[0050] Place the isocyanate component containing the low-boiling physical blowing agent into the first storage tank 11, close the first valve 14, connect the first pressurizing component 111 to the nitrogen cylinder and open the valve on the pressurizing component to increase the pressure in the first storage tank 11. Open the first circulation pump 32, the second circulation pump 33 and the piston compressor, so that the liquid phase in the isocyanate component enters the emulsifying device 31 through the hydrometer 36, the volumetric flowmeter 38 and the second circulation pump 33. At the same time, the gas phase in the isocyanate component is pressed into the emulsifying device 31 by the piston compressor 37 through the flow regulating valve 35, so that the liquid phase and the gas phase materials are emulsified in the emulsifying device and returned to the first storage tank 11 through the first circulation pump 32. After the circulation is monitored to be stable by the hydrometer 36 and the volumetric flowmeter 38, perform operations such as low-pressure circulation, high-pressure circulation and feeding as in Embodiment 2.

[0051] Embodiment 4

[0052] Refer to Figure 4 , this embodiment provides a 4# foaming gun head premixing system, which is different from the 3# foaming gun head premixing system in that the emulsifying device is a bilateral emulsifying device, including an emulsifying device 3 connected to the first material supply device 1 and an emulsifying device 3 connected to the second material supply device 2. The structures and connection methods of the two sets of emulsifying devices 3 are the same as those of the emulsifying device in the 3# foaming gun head premixing system.

[0053] When the mixing system of this embodiment is in use, place the polyol component containing the low-boiling physical blowing agent into the first storage tank 11, and place the isocyanate component containing the low-boiling physical blowing agent into the second storage tank 21. Similar to Embodiment 3, after the polyol component and the isocyanate component are both emulsified and circulated stably, perform operations such as low-pressure circulation, high-pressure circulation and feeding.

[0054] The above are only the preferred embodiments of the present utility model. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present utility model, several improvements and refinements can be made, and these improvements and refinements are also within the protection scope of the present utility model.

Claims

1. A pre-mixing system for a foaming machine head, characterized in that, It includes a first material supply device (1), a second material supply device (2), a mixing nozzle (4) and an emulsifying device (3); both the first material supply device (1) and the second material supply device (2) include a material tank, a feed pump and a first pipeline. The two material tanks are respectively connected to the two material inlets of the mixing nozzle (4) through the first pipeline and the feed pump; a pressurizing device is provided on one of the material tanks, and the pressurizing device is used to pressurize the material tank. The emulsifying device (3) includes an emulsifying equipment (31), a first circulation pump (32) and a second circulation pump (33). The emulsifying equipment (31) is respectively connected to the inlet and outlet of the material tank provided with the pressurizing device through the first circulation pump (32) and the second circulation pump (33).

2. The pre-mixing system of a foaming gun head according to claim 1, wherein Pressurizing devices are provided on both material tanks, and there are two sets of emulsifying devices (3), which are respectively connected to the two material tanks.

3. A pre-mixing system for a foaming gun head according to claim 1 or 2, characterized in that, The pressurizing device includes a pressurizing pipeline and a control valve provided on the pressurizing pipeline. One end of the pressurizing pipeline is connected to the material tank, and the other end is used to connect to a gas source.

4. A pre-mixing system for a foaming gun head according to claim 1 or 2, characterized in that, The material tank provided with the pressurizing device is connected to the feed pump through a stop valve.

5. A pre-mixing system for a foaming machine head according to claim 1 or 2, characterized in that, The emulsifying device (3) further includes a hydrometer (36) and a volume flowmeter (38). The hydrometer (36) and the volume flowmeter (38) are arranged on the connecting pipeline between the emulsifying equipment (31) and the material tank.

6. The pre-mixing system of a foaming machine head according to claim 1 or 2, characterized in that, Filters and flowmeters are also provided on the first pipeline. The filters and flowmeters are respectively arranged on the inlet side and the outlet side of the feed pump.

7. A pre-mixing system for a foaming gun head according to claim 1 or 2, characterized in that, Both the first material supply device (1) and the second material supply device (2) further include a second pipeline, a third pipeline, a check valve and a reversing valve. The two material tanks are respectively connected to the two circulating material outlets of the mixing nozzle (4) through two second pipelines. The first pipeline is connected to the third pipeline through the reversing valve. The third pipeline is connected to the second pipeline through a tee. A check valve is provided on the second pipeline, and the check valve is arranged between the third pipeline and the mixing nozzle (4).

8. A pre-mixing system for a foaming gun head according to claim 7, wherein, The emulsifying device (3) further includes a third material tank (34), and the third material tank (34) is used to add gaseous, liquid or solid materials to the emulsifying equipment (31) during the emulsification process.

9. A pre-mixing system for a foaming machine head according to claim 7, characterized in that, The emulsifying device (3) further includes a gas phase conveying device, and the gas phase conveying device is connected to the material tank and is used to send the gas phase components in the material tank into the emulsifying equipment (31) for emulsification.

10. A pre-mixing system for a foaming gun head according to claim 9, characterized in that, The gas phase conveying device includes a piston compressor. The inlet and outlet of the piston compressor are respectively connected to the material tank and the emulsifying equipment (31) through a gas phase conveying pipeline, and a flow regulating valve (35) is arranged on the gas phase conveying pipeline.

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