A cyclopentane foaming equipment

Abstract

The invention discloses a cyclopentane foaming device, including a white material tank, a black material tank, a mixing head for polyurethane foaming, and a high-pressure metering pump, wherein the high-pressure metering pump is used to pump white material and black material to the mixing head respectively; the pipelines for pumping white material and black material by the high-pressure metering pump are connected to energy accumulators, wherein the back pressure of the energy accumulator on the pipeline for pumping white material is greater than the back pressure of the energy accumulator on the pipeline for pumping black material; the white material tank, the black material tank, and the high-pressure metering pump are all located in an airtight enclosure, and an explosion-proof system is arranged in the airtight enclosure. The object of the present invention is to provide a cyclopentane foaming device, so as to solve the problems of multiple equipment drive motors, high energy consumption, and large safety hazards when using cyclopentane foaming in the prior art; and the problems of complex structure, high cost, large volume, and difficulty in miniaturization of equipment, which can not only ensure high-precision metering, but also can greatly improve safety performance and greatly reduce equipment cost, and significantly reduce energy consumption.

Description

Technical Field

[0001] The invention relates to the field of polyurethane foaming, and in particular to cyclopentane foaming equipment. Background Art

[0002] Polyurethane has many excellent properties, so it has a wide range of uses. The polyurethane high-pressure foaming machine is a machine that mixes polyether polyol (white material) and polymerized MDI (black material) through high-pressure counter-mixing for foaming reaction. High-pressure foaming machines are mainly used in the production of polyurethane rigid foam, soft foam, high-resilience products, such as refrigerator and freezer production, insulation board, insulation pipe, water heater, car seat cushion headrest, etc. A foaming agent needs to be added to the mixed raw materials for foaming. Traditional foaming agents such as Freon are not environmentally friendly and are strictly prohibited according to the Montreal Protocol. Cyclopentane has been widely used as an environmentally friendly foaming agent. However, cyclopentane as a foaming agent has the disadvantages of being flammable and explosive. In the actual foaming process, cyclopentane as a foaming agent is added to the white material, and the main component of the white material is polyether. For polyurethane foaming, there are strict requirements on the feeding ratio and pressure of white and black materials, otherwise it is easy to affect the foaming quality.

[0003] The inventor of the present application is the designer of the first cyclopentane foaming equipment in China, and began to produce cyclopentane foaming equipment on a large scale in China in 2003. The inventor of the present application found that the prior art has the following defects in the process of implementing the prior art: the high-pressure metering system mostly uses a multi-piston pump in conjunction with a motor, a frequency converter, a magnetic coupling, a pressure sensor and other equipment to achieve continuous feeding. Although this existing feeding technology has accurate metering, it is complex in structure, large in volume, and difficult to move. In addition, the manufacturing and use, and later maintenance costs are high and expensive, which is not conducive to use in a small space, and is not conducive to the large-scale promotion of polyurethane foaming equipment. In addition, since cyclopentane is flammable and explosive, and a large number of live devices such as motors are used as driving parts in the prior art, it is easy to cause ignition and electrostatic deposition, thereby increasing the probability of combustion and explosion of the leaked cyclopentane gas, so the safety hazard during cyclopentane foaming is increased. In addition, the total power of the existing foaming equipment driven by a large number of motors is about 30-40Kw, and there are also problems of high energy consumption, high manufacturing cost and extremely high use cost. Summary of the invention

[0004] The purpose of the present invention is to provide a cyclopentane foaming device to solve the problems in the prior art of using cyclopentane for foaming, such as multiple driving motors, high energy consumption, and great potential safety hazards; and the device has a complex structure, high cost, large volume, and difficulty in miniaturization. The device can not only ensure high-precision metering, but also greatly improve safety performance, greatly reduce equipment costs, and significantly reduce energy consumption.

[0005] The present invention is achieved through the following technical solutions:

[0006] A cyclopentane foaming device comprises a white material tank, a black material tank, a mixing head for polyurethane foaming, and a high-pressure metering pump, wherein the high-pressure metering pump is used to pump the white material and the black material to the mixing head respectively; the pipelines for the high-pressure metering pump to pump the white material and the black material are connected to energy accumulators, wherein the back pressure of the energy accumulator on the pipeline for pumping the white material is greater than the back pressure of the energy accumulator on the pipeline for pumping the black material; the white material tank, the black material tank, and the high-pressure metering pump are all located in an airtight enclosure, and an explosion-proof system is arranged in the airtight enclosure.

[0007] First, the inventor found in the research process that the metering methods of foaming equipment in the prior art include two types: metering equipment driven by a motor and metering equipment with a single plunger reciprocating pressurized metering cylinder. However, the metering equipment driven by a motor always has the problems of complex structure, large volume, difficulty in moving, high manufacturing and maintenance costs, high price, and is not conducive to use in a small space. The main reason is that the high-pressure metering system used for stable output of white and black materials mostly uses a multi-plunger pump structure, and then cooperates with motors, frequency converters, magnetic couplings, pressure sensors and other equipment to achieve its function. The metering system composed of so many devices will inevitably lead to a complex equipment structure and a large volume, which will lead to a long-term high cost, and also lead to extremely high power and energy consumption when the equipment is used. The structure of the metering equipment using a single plunger reciprocating pressurized metering cylinder cannot adapt to and meet the special technical requirements of the cyclopentane pouring foaming field due to many design defects in the prior art, and can only be used in the spraying field with extremely low quality requirements. For this reason, the present application first proposes a cyclopentane foaming device, which uses a high-pressure metering pump to directly pump white material and black material, abandons the equipment such as multiple plunger pumps, motors, frequency converters, magnetic couplings in the prior art, significantly reduces the volume of the equipment, reduces the materials used, and thus greatly reduces the equipment cost, realizes the miniaturization of the cyclopentane foaming device, and enables the cyclopentane foaming device to be used in a small space; and because the present application abandons the above-mentioned many devices, the rated power is extremely low, the working energy consumption is significantly reduced, and the green, low-carbon, and environmentally friendly effects are achieved, with extremely high economic and social benefits. Of course, the high-pressure metering pump described in the present application refers to a high-pressure metering pump that can meet the pressure required for polyurethane foaming (about 8 to 15 MPa).

[0008] Secondly, cyclopentane has the characteristics of being flammable and explosive. In the prior art, due to the large-scale use of live equipment such as motors as driving parts, ignition or electrostatic deposition is prone to occur, which in turn leads to an increase in the probability of combustion and explosion of the leaked cyclopentane gas, resulting in a large potential safety hazard when cyclopentane foams. In this application, the inventors took into account the flammable and explosive characteristics of cyclopentane. In order to cooperate with the safe use of the high-pressure metering pump in this equipment, the white material tank, the black material tank, and the high-pressure metering pump are all arranged in an airtight enclosure, and the explosion-proof system in the airtight enclosure is used to avoid safety accidents caused by cyclopentane leakage, which can greatly improve safety performance compared to the prior art.

[0009] Finally, the inventor discovered during the research process that the metering equipment of the single-plunger reciprocating booster metering cylinder in the prior art has unstable foaming effect during polyurethane foaming and is prone to produce defective products with poor effect. The reason is the uneven output and unstable feeding of white and black materials. Once the output of white and black materials is uneven and the feeding is unstable, the raw materials cannot be fully and evenly mixed, thus affecting the foaming quality. The inventor analyzed the deep reasons for the uneven output and unstable feeding as follows: This type of metering system generally uses a reciprocating booster metering cylinder, which will experience instantaneous pressure fluctuations when it moves to the two ends of the stroke for reversing. Please refer to Figure 1 , Figure 1The horizontal axis is time, and the vertical axis is the ratio of the flow rate to the pressure of the high-pressure metering pump head. It can be seen that in the traditional foaming process, the pressure and flow rate output by the high-pressure metering pump will continue to fluctuate. When in the trough (that is, when the plunger moves to both ends of the stroke for reversing), the flow rate and pressure of the white material and the black material are unstable, resulting in the inability to fully and evenly mix the two raw materials. To this end, the present application first connects accumulators to the pipelines for pumping white and black materials by the high-pressure metering pump. After the white and black materials are output from the high-pressure metering pump, they enter their respective corresponding pipelines and reach the mixing head after passing through their respective corresponding accumulators. The flow rate and pressure of the white and black materials that are about to reach the mixing head are compensated by two accumulators. When the present application is used, the back pressure of the accumulator is lower than the output pressure of the pump head end of the high-pressure metering pump, so in normal operation, the accumulator is pressurized to store energy; when the piston moves to the two ends of the stroke for reversal, and the flow and pressure drop instantaneously, the accumulator can instantly release energy and compensate for the fluctuations in flow and pressure caused by the piston movement, thereby ensuring that the output pressure and flow of the white material and the black material remain stable, thereby ensuring that the white material and the black material are fully and evenly mixed at high pressure at the mixing head and improving the foaming quality. In addition, in this field, in order to ensure that the white material and the black material are output synchronously at the mixing head for high-pressure mixing and foaming, the output pressures of the white material and the black material are equal, or set to different values ​​as needed. Therefore, based on the aforementioned technical solution, the conventional idea that technicians in this field can easily think of is that the back pressures of the two accumulators must also be equal so that the output pressures of the white material and the black material can remain unchanged. However, the inventors found in the further research process that when the back pressure of the two accumulators is set to the same according to the conventional idea, a relatively stable output flow and pressure cannot be obtained. After exploring the reasons, it was finally concluded that it was caused by the difference in viscosity between the white material and the black material: the viscosity of the white material is greater than that of the black material. Under the same output pressure of the pump head, the output efficiency of the white material with greater viscous resistance is very likely to be lower than the output efficiency of the black material with smoother flow; so even if accumulators are added to the output material pipes of the white material and the black material, although the fluctuations of pressure and flow can be reduced, if the back pressures of the two accumulators are the same, a very stable pressure and flow output curve cannot be obtained. For this reason, the inventors continued to take improvement measures: the back pressure of the accumulator on the pipeline for pumping white material is greater than the back pressure of the accumulator on the pipeline for pumping black material. Under this scheme, the back pressure of the accumulator on the white material pipeline is greater, and the energy stored in normal operation is also greater. When the piston moves to the two ends of the stroke for reversing and the flow and pressure drop instantaneously, the energy that can be released by the accumulator on the pipeline for pumping white material is also greater, and the output compensation of the white material is also greater. By providing greater compensation energy for white materials with higher viscosity, it is ensured that during the continuous foaming process, the output efficiency (flow and pressure) of the white material remains stable, so as to obtain better and more stable foaming quality.In summary, this application connects accumulators to the pipelines for pumping white and black materials with high-pressure metering pumps and specifies the back pressure of the two accumulators, which can not only compensate for the fluctuations in flow and pressure caused by piston movement, but also overcome the technical difficulties of different extrusion flows and thus changes in the ratio due to different viscosities of the two raw materials, and ultimately ensure that the output of white and black materials remains stable, and obtains a very stable pressure and flow output effect, thereby ensuring that the white and black materials are fully and evenly mixed at high pressure at the mixing head, significantly improving the foaming quality. Of course, this application is applicable to polyurethane foaming operations in the context of various foaming agents, and is particularly applicable to the use of cyclopentane as a foaming agent.

[0010] The energy accumulator is an airbag type energy accumulator, wherein the inflation pressure of the energy accumulator on the pipeline for pumping white material is 0.5 to 3 MPa greater than the inflation pressure of the energy accumulator on the pipeline for pumping black material. If the back pressure difference between the two energy accumulators is the same or too small, it will not be able to provide greater compensation energy for the white material with higher viscosity; if the pressure difference between the two energy accumulators is too large, it may cause the white material to be conveyed more efficiently than the black material. Therefore, in this scheme, the inflation pressure of the energy accumulator on the pipeline for pumping white material is limited to 0.5 to 3 MPa greater than the inflation pressure of the energy accumulator on the pipeline for pumping black material. Within this pressure difference range, the best feeding effect can be achieved, so that the pressure and flow output curves remain stable for a long time during the foaming process.

[0011] The high-pressure metering pump includes a driving member, and the driving member is used to drive the white material metering cylinder and the black material metering cylinder to move simultaneously. The white material metering cylinder pumps white material from the white material tank, and the black material metering cylinder pumps black material from the black material tank. In this solution, the white material and the black material are driven by the white material metering cylinder and the black material metering cylinder respectively for pumping, and the two metering cylinders are driven by the same driving member for movement, so as to ensure that the white material metering cylinder and the black material metering cylinder can always keep synchronous movement, thereby ensuring that the white material and the black material are output at the same time.

[0012] The volume of the white material metering cylinder is smaller than that of the black material metering cylinder. On the basis of the above research, the inventor further analyzed the reasons for the uneven output of raw materials and black materials and the unstable feeding, and found that it also includes: since the white material metering cylinder and the black material metering cylinder are driven by a driving member, the strokes of the two are equal; while the prior art uses two metering cylinders of equal volume, and only adjusts the flow at the outlet end. This method does not take into account the ratio requirements and viscosity difference of white and black materials. In actual work, the energy consumed by driving the white material with greater viscosity must be more, so the pressure at the output end of the white material is lower, the pressure fluctuation is more obvious, and the trough pressure is lower. For this reason, the present scheme sets the volume of the white material metering cylinder to be smaller than that of the black material metering cylinder. This setting not only fully considers the viscosity difference between white and black materials, but also can relatively increase the pressure at the output end of the white material metering cylinder, further reduce the fluctuation of pressure and flow, and ensure the stability of pressure and flow; at the same time, the present scheme significantly improves the accuracy of the mixing ratio of the two raw materials in the polyurethane foaming process, and reduces the control difficulty.

[0013] Preferably, the volume ratio of the white material metering cylinder to the black material metering cylinder is 1:1.1 to 1.3. The volume ratio of the two metering cylinders in this range realizes precise control of pressure and ratio, and can be applied to the ratio requirements when different raw materials such as cyclopentane, 141b, 245fa, water, etc. are used as foaming agents, and has a wider applicability.

[0014] The driving part is a hydraulic cylinder, and also includes a hydraulic station matched with the hydraulic cylinder. A heat sink is connected to the pipeline of the hydraulic cylinder backflowing to the hydraulic station, and the heat sink uses a chiller as a cold source. In the existing cyclopentane equipment technology, due to the large-scale use of electric devices such as motors as driving parts, ignition or electrostatic deposition is prone to occur, which in turn leads to an increase in the probability of combustion and explosion of the leaked cyclopentane gas, resulting in a large safety hazard when cyclopentane foams. However, the present application uses a hydraulic cylinder as a direct driving part, and the hydraulic cylinder located in the airtight enclosure is not charged, and will not produce ignition or electrostatic deposition during the working process. The only motor of the entire equipment is used as a driving component of the hydraulic station. The hydraulic station is located outside the airtight enclosure. Even if ignition or electrostatic deposition is generated due to quality problems or equipment failure, it will not affect the safety in the airtight enclosure. Therefore, the present application can significantly improve the safety performance. In addition, the inventor's design ideas also include: if the cylinder is used as the driving part of the high-pressure metering pump for pneumatic driving, it is difficult to accurately maintain the output displacement for a long time due to the strong compressibility of the gas and the great influence of temperature changes, which easily leads to errors in the ratio and affects the foaming quality; at the same time, the gas compression ratio is insufficient, and the output pressure is generally less than 5MPa, which cannot meet the mixing pressure of the raw materials (8-15MPa) and cannot be used in this application. Therefore, this scheme uses a hydraulic cylinder as a driving part, which can conveniently meet the higher mixing pressure requirements; the hydraulic cylinder drives the white material metering cylinder and the black material metering cylinder to move at the same time, and the hydraulic station supplies oil. The hydraulic oil enters the hydraulic cylinder from the hydraulic station to work, and then flows back to the hydraulic station. During the reflux process, the heat is dissipated through the heat dissipation device. The traditional heat dissipation method is air-cooled heat dissipation, which uses a fan to blow air to the hydraulic station to reduce the temperature of the equipment. However, this method cannot effectively reduce the temperature of the hydraulic oil in actual work. The inventors also found during the research process that whether the temperature of the hydraulic oil in this application is stable will also affect whether the output raw material flow is stable. Specifically: once the temperature of the hydraulic oil in the entire hydraulic system continues to rise due to continuous work and cannot be cooled down in time, it will cause the viscosity of the hydraulic oil to be disordered and the flow state to be unstable, which will lead to differences in the output power of different strokes of the hydraulic cylinder. This difference will act on the white and black materials being pumped, and will be reflected as unstable flow and disordered flow of white and black materials, resulting in uneven output and unstable feeding, which will eventually lead to the inability to fully and evenly mix the raw materials, the inability to maintain a quantitatively stable output of raw materials, and the uncontrollable foaming quality. For this reason, this application uses a chiller as a cold source, and the chiller supplies cooling water to the heat dissipation device. The refluxed hydraulic oil exchanges heat with the cold water when passing through the heat dissipation device to achieve the effect of rapid heat dissipation.It is worth mentioning that although the use of water cooling technology is relatively mature, in this field, there has been no record of the technology of water cooling and temperature control of hydraulic oil in order to avoid unstable raw material supply interfering with foaming quality. The reason is that the existing technology does not take into account the correlation between poor foaming quality and the heat dissipation of the hydraulic oil that drives the metering cylinder. The inventor of this case has devoted a lot of creative work to discover the key to this technical problem.

[0015] The explosion-proof system includes a detection probe for detecting the leakage concentration of cyclopentane, a blower for discharging the gas in the airtight enclosure, and the blower is controlled by the detection signal of the detection probe; the airtight enclosure and all the equipment in the airtight enclosure are grounded. The application sets an airtight enclosure, and white material tanks, black material tanks, and high-pressure metering pumps are all placed in the airtight enclosure, and the confined space formed by the airtight enclosure is used to avoid the leakage of cyclopentane. At the same time, the cyclopentane leakage concentration in the airtight enclosure is detected by the detection probe. When the cyclopentane leakage concentration reaches the set value, the blower is started to exhaust the inside of the airtight enclosure, and the extracted gas is discharged to the air in the open space outside. The application integrates white material tanks, black material tanks, and high-pressure metering pumps in the airtight enclosure, while improving the safety factor, it is also conducive to the miniaturization and large-scale development of polyurethane foaming equipment, so that cyclopentane equipment can obtain higher safety and economy, reduce the procurement cost and use risk of small and medium-sized producers, and promote industrial development. In addition, the airtight enclosure and all equipment located in the airtight enclosure, such as white material tanks, black material tanks, and high-pressure metering pumps, are grounded to further ensure safety during the work of this application.

[0016] The fan includes a primary fan and a secondary fan, and the power of the secondary fan is greater than that of the primary fan; when the detection probe detects that the cyclopentane concentration reaches 20% of the lower explosion limit (LEL), the primary fan starts; when the detection probe detects that the cyclopentane concentration reaches 40% of the lower explosion limit (LEL), the secondary fan starts. In this scheme, the fan is started in two stages, and the power of the primary fan is relatively small, so the starting standard is lower, and it is started in a low-risk situation, that is, it is started when the detection probe detects that the cyclopentane concentration reaches 20% of the lower explosion limit. The power of the secondary fan is relatively large, so the starting standard is higher, and it is started in a high-risk situation, that is, it is started when the detection probe detects that the cyclopentane concentration reaches 40% of the lower explosion limit. The above-mentioned lower explosion limit refers to the lower limit of the explosive concentration range of cyclopentane in the air. This scheme can significantly improve the safety of on-site operations and significantly reduce safety hazards by starting the two-stage fan in stages.

[0017] The white material tank and the black material tank are both covered with a temperature-controlled water jacket, and also include a thermostat for adjusting the temperature of the temperature-controlled water jacket. In the existing metering technology of the single-plunger reciprocating booster metering cylinder, in order to solve the fluidity problem of the raw material, the raw material is directly electrically heated to improve the fluidity of the raw material. However, this method has the following disadvantages: when cyclopentane is used as a foaming agent, the boiling point of cyclopentane is extremely low, and the boiling point is 49.3°C under standard atmospheric pressure. The direct electric contact heating method has the following two disadvantages: (1) There are huge safety hazards; (2) It is very easy to cause the cyclopentane near the heat source to gasify and lose the foaming agent function, which is very unfavorable for use. In the present application, the temperature of the white material tank and the black material tank is controlled as a whole during the polyurethane foaming process to ensure the stability of the performance of the white and black materials being foamed. In this solution, the temperature-controlled water jacket is covered on the outside of the white material tank and the black material tank, and the water jacket is filled with water, and the temperature of the water in the water jacket is adjusted by a thermostat. First, the temperature-controlled water jacket is used to indirectly heat the white material tank and the black material tank as a whole, so that the overall heating temperature of the material tank is more uniform, thereby solving the problem of uneven internal raw material temperature; and because of the indirect heating, the safety hazard of direct heating is avoided; secondly, there is no phenomenon of premature gasification of cyclopentane due to excessive local heating temperature; finally, the large specific heat capacity of water is used to ensure the stability of the raw material temperature and avoid local rapid heating or cooling. The constant temperature device in this scheme can use the heating and cooling devices in the prior art, and perform heating or cooling operations as needed.

[0018] The white material tank and the black material tank are both equipped with a stirrer, a pressure reducing valve, and a feeding pump. Inert gas is filled in the white material tank and the black material tank, and the feeding pump is used to automatically feed the corresponding material tank. The stirrer is used to stir the raw materials inside the white material tank and the black material tank to ensure that the raw materials are fully mixed, and at the same time further improve the uniformity of temperature and performance. The pressure reducing valve is used to fill 2 to 3 bar of inert gas into the tank to isolate and prevent air from entering and mixing with the cyclopentane gas in the tank to ensure safety of use. In addition, when the liquid level in the material tank is low, the raw materials can be automatically replenished into the tank through the feeding pump.

[0019] Furthermore, the high-pressure metering pump is a vertical high-pressure metering pump or a horizontal high-pressure metering pump;

[0020] The vertical high-pressure metering pump comprises a driving member with an output end facing downward, and two cylinder bodies located below the driving member, the two cylinder bodies are respectively a white material metering cylinder and a black material metering cylinder; the piston rods of the two cylinder bodies are connected to the output end of the driving member, the bottom of the piston rod is connected to the first piston, and the first piston moves in the piston cavity; the cylinder body comprises an upper seat and a base distributed on the upper and lower sides, a raw material inlet is provided on the base, and a raw material outlet is provided on the upper seat; a bottom valve is provided on the top of the base, and a sealing member gland is provided at the bottom of the piston cavity, and the bottom valve and the sealing member gland both include a one-way valve that can be conducted from bottom to top; there is a gap between the first piston and the inner wall of the cylinder body, and a through hole connected to the gap is provided on the first piston;

[0021] The horizontal high-pressure metering pump includes a horizontal driving member, both opposite ends of the driving member have output ends, and also includes a main cylinder body located on both sides of the driving member, the two output ends are respectively connected to the piston rods of the two main cylinder bodies, the two main cylinder bodies are respectively a white material metering cylinder and a black material metering cylinder; the piston of the main cylinder body is slidably sealed with the inner wall of the main cylinder body, and there is a gap between the piston rod of the main cylinder body and the inner wall of the main cylinder body; the end of the main cylinder body away from the linear driving member is connected to the base, the bottom of the base is a feed joint, and the top of the base is a valve seat, the feed joint and the valve seat are both provided with a one-way valve that conducts from bottom to top, the valve seat is also connected to the auxiliary cylinder body, and the auxiliary cylinder body is located above the corresponding main cylinder body; the auxiliary cylinder body is also connected to the upper seat, the bottom of the upper seat is connected to the main cylinder body, and the top of the upper seat is opened. A raw material outlet.

[0022] This scheme also provides two specific structures of high-pressure metering pumps, in which the two cylinders of the vertical high-pressure metering pump are connected in parallel, with excellent synchronization; while the white material and black material of the horizontal high-pressure metering pump are driven by two sides respectively, that is, when the main cylinder on one side is sucking, the main cylinder on the other side is pushing, so the output of the white material and the black material will not interfere with each other. Compared with the vertical synchronous pushing and synchronous suction pumping method, the two main cylinders will not be damaged due to the different forces caused by the viscosity difference between the white material and the black material, which can significantly improve the service life. The above two high-pressure metering pumps are both simple in structure. Through a driving part that serves as the power source of the white material metering cylinder and the black material metering cylinder at the same time, the white material and the black material are output at the same time, which significantly reduces the cost, greatly reduces the cost of cyclopentane foaming equipment, and realizes the purpose of continuous feeding through a single piston, overcoming the problem that the existing technology requires the use of multiple plunger pumps to ensure continuous feeding of white or black materials for cyclopentane foaming.

[0023] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0024] 1. The cyclopentane foaming equipment of the present invention significantly reduces the equipment volume and materials used, thereby greatly reducing the equipment cost, realizing the miniaturized production of the cyclopentane foaming equipment, so that the cyclopentane foaming equipment can also be used in a small space, and has extremely high economic and social benefits.

[0025] 2. Considering the inflammable and explosive characteristics of cyclopentane, and in order to cooperate with the safe use of high-pressure metering pump in this equipment, the white material tank, black material tank and high-pressure metering pump without strong electricity are all arranged in the airtight enclosure, and the safety accident caused by the leakage of cyclopentane is avoided by the explosion-proof system in the airtight enclosure, which can greatly improve the safety performance compared with the prior art. And while overcoming the potential safety hazard, it is also conducive to the miniaturization and large-scale development of cyclopentane foaming equipment, because of its reliable safety and excellent low energy consumption, more small and medium-sized producers can afford cyclopentane foaming equipment, and promote industrial development. In addition, the application can reduce the energy consumption of cyclopentane foaming equipment to about 1 / 6 to 1 / 8 of the prior art, fully responding to the industrial upgrading trend of green, low-carbon, energy-saving and environmental protection.

[0026] 3. The present invention solves the problem of uneven mixing ratio of the existing single-plunger reciprocating pressurized metering cylinder metering equipment: by setting the volume ratio of the two metering cylinders, it can be suitable for the ratio requirements of different raw materials such as cyclopentane, 141b, 245fa, water, etc. when used as foaming agents, and has excellent applicability; the high-pressure metering pump designed and used in this application makes the traditional intermittent metering cylinder become a true metering pump with continuous feeding capability.

[0027] 4. The present invention provides a unique material temperature treatment technology: the white material tank and the black material tank are both covered with a temperature-controlled water jacket, the water jacket is filled with water, and the temperature of the water in the water jacket is adjusted by a constant temperature device. First, the white material tank and the black material tank are indirectly heated or cooled as a whole by the temperature-controlled water jacket, so that the overall heating temperature of the material tank is more uniform, thereby solving the problem of uneven internal raw material temperature; and because of the use of indirect heating or cooling, the safety hazard of direct heating is avoided; secondly, there is no phenomenon of premature gasification of cyclopentane due to excessive local heating temperature; finally, the large specific heat capacity of water is utilized, which is conducive to ensuring the stability of the raw material temperature and avoiding local rapid heating or cooling.

[0028] 5. The present invention solves the problem of pressure pulsation in the process of pumping materials: by setting two accumulators and limiting their respective back pressures, it can not only compensate for the fluctuations in flow and pressure caused by the reciprocating motion of the piston, but also overcome the technical difficulties of different extrusion flow rates and thus changes in the ratio caused by different viscosities of the two raw materials. Ultimately, it ensures that the output of white and black materials remains stable, and obtains a very stable pressure and flow output effect, thereby ensuring that the white and black materials are fully and evenly mixed at high pressure at the mixing head, significantly improving the foaming quality.

[0029] 6. The present invention improves the accuracy of the output flow rate: the material temperature uniformity is significantly improved through a unique material temperature processing technology, and the flow rate accuracy is improved. In addition, a new understanding of the technical problem of unstable flow rate is gained: the hydraulic oil temperature in the hydraulic system is uneven and cannot be cooled down in time, which will cause the hydraulic oil viscosity to be disordered and the flow state to be unstable, which will lead to differences in the output power of different strokes of the hydraulic cylinder. This difference acts on the pumped white and black materials, which will be reflected as unstable flow and disordered flow of the white and black materials, resulting in uneven output and unstable feeding, which ultimately leads to the inability to fully and evenly mix the raw materials and affects the foaming quality. The present application uses a chiller as a cold source. The chiller supplies cooling water to the heat dissipation device. The refluxed hydraulic oil exchanges heat with the cold water when passing through the heat dissipation device, thereby achieving a rapid heat dissipation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0031] Figure 1 It is an output curve diagram of a high-pressure metering pump in the prior art;

[0032] Figure 2 It is a structural schematic diagram of a specific embodiment of the present invention;

[0033] Figure 3 It is a structural schematic diagram of a specific embodiment of the present invention;

[0034] Figure 4 It is an output curve diagram of a high-pressure metering pump in a specific embodiment of the present invention;

[0035] Figure 5 It is a structural schematic diagram of a specific embodiment of the present invention;

[0036] Figure 6 A half-section schematic diagram of a high-pressure metering pump in a specific embodiment of the present invention;

[0037] Figure 7 It is a partial cross-sectional view of a white material metering cylinder or a black material metering cylinder in a specific embodiment of the present invention;

[0038] Figure 8 For specific embodiments of the present invention Figure 6 Sectional view of the BB direction line;

[0039] Fig. 9 A half-section schematic diagram of a high-pressure metering pump in a specific embodiment of the present invention;

[0040] Fig.10 for Fig. 9 A partial enlarged view of the main cylinder on one side.

[0041] Marks and corresponding parts names in the attached drawings:

[0042] 1-cantilever, 2-human-machine interface, 3-pressure sensor, 4-hydraulic station, 5-high-pressure metering pump, 6-pressure reducing valve, 7-black material tank, 8-mixer, 9-white material tank, 10-liquid level sensor, 11-temperature control water jacket, 12-feeding pump, 13-constant temperature element, 14-temperature sensor, 15-fan exhaust port, 16-Y-type filter, 17-detection probe, 18-heat dissipation device, 19-energy storage device, 20-water chiller, 21-PLC electronic control system, 22-mixing head, 23-driving part, 24-white material metering cylinder, 25-black material metering cylinder, 26-check valve; 27-base, 28-base plug, 29-O ring, 30-first small ball, 31-bottom valve, 32-two-way piston seal, 33-seal cover, 34-PTFE pad, 35-one-way piston seal, 36-second small ball, 37-first piston, 38-piston rod, 39-vertical plate, 40-upper seat, 41-first tie rod seal, 42-second tie rod seal, 43-upper seat cover, 44-lubricating cup, 45-column, 46-inductive proximity switch, 47-first fixed plate, 48-rear vertical plate, 49-guide shaft, 50-deep groove ball bearing, 51-shaft elastic retaining ring, 52-connecting frame, 53-second fixed plate, 54-front vertical plate, 55-dustproof ring, 56-copper sleeve, 57-third tie rod seal, 58-cylinder upper seat, 59- Wear-resistant ring, 60-second piston, 61-cylinder body, 62-cylinder seat, 63-solenoid valve plate, 64-solenoid reversing valve, 65-cylinder body, 66-raw material inlet, 67-raw material outlet, 68-through hole, 69-feed connector, 70-third small ball, 71-ball baffle, 72-valve seat, 73-fourth small ball, 74-plug, 75-sub-cylinder body, 76-proximity switch mounting plate, 77-proximity switch, 78-solenoid valve mounting plate, 79-cylinder fixing plate, 80-locking nut, 81-fourth tie rod seal, 82-third piston, 83-fifth tie rod seal, 84-sixth tie rod seal, 85-main cylinder body, 86-valve one, 87-valve two. DETAILED DESCRIPTION

[0043] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0044] Embodiment 1:

[0045] like Figure 2 , Figure 3 and Figure 5A cyclopentane foaming device shown includes a white material tank 9, a black material tank 7, a mixing head 22 for polyurethane foaming, and a high-pressure metering pump 5, which is used to pump white material and black material to the mixing head 22 respectively; the pipelines for pumping white material and black material by the high-pressure metering pump 5 are both connected to an accumulator 19, wherein the back pressure of the accumulator 19 on the pipeline for pumping white material is greater than the back pressure of the accumulator 19 on the pipeline for pumping black material. In this embodiment, the accumulator 19 is an airbag accumulator, wherein the inflation pressure of the accumulator 19 on the pipeline for pumping white material is 0.5 to 3 MPa greater than the inflation pressure of the accumulator 19 on the pipeline for pumping black material; the gas filled in the accumulator airbag is nitrogen.

[0046] On the basis of the above-mentioned nitrogen filling pressure, the output pressure at the pump head end of the high-pressure metering pump 5 in this embodiment is 10-15 MPa, the back pressure of the accumulator 19 on the pipeline for pumping white material is controlled at 8-9 MPa, and the back pressure of the accumulator 19 on the pipeline for pumping black material is controlled at 6-7 MPa; according to experiments, within this pressure range, a relatively stable output curve can be obtained, which effectively improves the uniformity and stability of polyurethane foaming.

[0047] Preferably, as shown in the figure, a one-way valve 26 is provided at the upstream end of the two accumulators 19 to ensure that the accumulators 19 release energy to the downstream end to avoid backflow of raw materials.

[0048] Preferably, the mixing head 22 in this embodiment uses a self-cleaning mixing head, which can automatically clean the internal flow channel after each operation, and can circulate with the corresponding material tank when not working, that is, the raw material is pumped to the mixing head, flows through the mixing head and then flows back into the material tank. The above self-cleaning mixing head can be realized by those skilled in the art.

[0049] This embodiment is applicable to polyurethane foaming operations under various foaming agents, and can especially meet the use requirements when cyclopentane is used as a foaming agent.

[0050] Embodiment 2:

[0051] On the basis of Example 1, Figure 2 , Figure 3 and Figure 5As shown, the high-pressure metering pump 5 includes a driving member 23, and the driving member 23 is used to drive the white material metering cylinder 24 and the black material metering cylinder 25 to act simultaneously. The white material metering cylinder 24 pumps white material from the white material tank 9, and the black material metering cylinder 25 pumps black material from the black material tank 7. The volume of the white material metering cylinder 24 is smaller than the volume of the black material metering cylinder 25. In this embodiment, the volume ratio of the white material metering cylinder 24 to the black material metering cylinder 25 is 1:1.2. In this embodiment, the driving member 23 is a hydraulic cylinder, and also includes a hydraulic station 4 matched with the hydraulic cylinder. The pipeline from the hydraulic cylinder to the hydraulic station 4 is connected to a heat sink 18, and the heat sink 18 uses a chiller 20 as a cold source.

[0052] The inventor found in the test process that if the volume of the white material metering cylinder 24 and the black material metering cylinder 25 are equal, the pressure at the output end of the white material will always be slightly lower than the pressure at the output end of the black material. In actual applications, since the viscosity of the white material is higher than that of the black material, the pressure of the white material is generally required to be slightly higher than that of the black material in order to be fully mixed. Therefore, the prior art is not conducive to the stable and uniform mixing of polyurethane foaming. According to the present embodiment, the volume ratio of the white material metering cylinder 24 to the black material metering cylinder 25 is set to 1:1.2, which can meet the reasonable output pressure of the two raw materials, and this volume ratio can be applied to the ratio requirements when raw materials of different viscosities such as cyclopentane, 141b, 245fa, and water are used as foaming agents, and has excellent applicability.

[0053] In this embodiment, the white material metering cylinder 24 and the black material metering cylinder 25 are driven by the same hydraulic cylinder to maintain the synchronous output of white material and black material. The total power of the existing foaming equipment driven by a large number of motors is about 30 to 40Kw when working, which consumes a lot of energy and indirectly leads to extremely high manufacturing and use costs. However, this embodiment has only one motor matched with the hydraulic station. After testing, the rated power is only 3 to 4Kw; even with the explosion-proof heater and chiller 20 as the temperature control element 13, the rated power is only 5.5Kw. Obviously, this embodiment can reduce the energy consumption of cyclopentane foaming equipment to about 1 / 6 to 1 / 8 of the existing technology, fully responding to the green, low-carbon, energy-saving and environmentally friendly industrial upgrading trend, and reducing the use cost.

[0054] In this embodiment, the heat dissipation device 18 is a plate heat exchanger, and cooling water is circulated to the plate heat exchanger by a chiller 20. During the reflux process of the hydraulic oil, heat exchange and cooling are performed through the plate heat exchanger, ensuring that all the hydraulic oil returning to the hydraulic station 4 has been effectively cooled, thereby ensuring the temperature of the hydraulic oil input to the hydraulic cylinder is stable, eliminating unstable flow caused by uneven temperature, thereby ensuring uniform output of white and black materials and stable feeding.

[0055] This embodiment improves the stability of raw material output, pressure, flow rate and ratio in the polyurethane foaming process from the following three aspects: first, the pressure regulation of the two accumulators, second, the control of the volume of the white material metering cylinder and the black material metering cylinder, and finally, the improvement of the heat dissipation method of the hydraulic oil. After combining the above three technical means, the following results were obtained: Figure 4 From the output curve shown, it can be seen that the pressure and flow are very stable, the raw materials are fully and evenly mixed, and the quality of the final polyurethane product is also significantly improved, and the uniformity, fineness and flatness of the cross-section of the finished product are significantly improved.

[0056] Embodiment 3:

[0057] Based on any of the above embodiments, Figure 5 As shown, the white material tank 9, the black material tank 7, and the high-pressure metering pump 5 are all located in an airtight enclosure, and a detection probe 17 for detecting the concentration of cyclopentane is arranged in the airtight enclosure, and a fan for discharging the gas in the airtight enclosure is also included, and the fan is controlled by the detection signal of the detection probe 17; the airtight enclosure and all the equipment in the airtight enclosure are grounded, and the grounding resistance is ensured to be less than 4Ω. The exhaust end of the fan passes through the fan exhaust port 15 to the outside of the airtight enclosure, so as to discharge the gas.

[0058] The pressure sensor 3 is used to monitor the pressure of the white material and the black material before they enter the mixing head. When the pressure difference between the two is too large, it is convenient to adjust the component pressure at the mixing head in time so that the output pressures of the white material and the black material are close to or even equal to ensure full mixing and uniform foaming.

[0059] Wherein, the fan includes a primary fan and a secondary fan, and the power of the secondary fan is greater than that of the primary fan; when the detection probe 17 detects that the cyclopentane concentration reaches 20% of the lower explosion limit, the primary fan starts; when the detection probe 17 detects that the cyclopentane concentration reaches 40% of the lower explosion limit, the secondary fan starts.

[0060] Preferably, Figure 2 , Figure 3 and Figure 5As shown, the white material tank 9 and the black material tank 7 are both covered with a temperature control water jacket 11, and also include a temperature control element 13 for adjusting the temperature of the temperature control water jacket 11. The white material tank 9 and the black material tank 7 are both provided with a stirrer 8, a pressure reducing valve 6, and a feeding pump 12. The white material tank 9 and the black material tank 7 are both filled with nitrogen as protection. The feeding pump 12 is used for automatic feeding of the corresponding material tank; the automatic feeding method can be: a liquid level sensor is set correspondingly, and the feeding pump 12 is automatically started when the liquid level drops to a predetermined height. The temperature sensor 14 is used to monitor the temperature of the raw materials in the corresponding material tank, so as to control the temperature control element 13 and the chiller 20 for heating or cooling: when the raw materials need to be heated, the temperature control heating element works to increase the temperature; when the raw materials need to be cooled, the temperature control cooling element works to cool down. The white material tank 9 and the black material tank 7 are both equipped with a liquid level sensor 10 for monitoring the internal raw material liquid level. When the liquid level reaches the set lower limit, the corresponding feeding pump 12 automatically replenishes the raw materials from the outside. The agitator 8 in this embodiment is a pneumatic agitator, which has no risk of explosion caused by electricity compared to common motor agitation.

[0061] A more preferred embodiment is: Figure 2 As shown, the cooling water output by the chiller 20 first enters the temperature control water jacket 11 and then enters the plate heat exchanger, thereby achieving full utilization of the chiller. Figure 2 In the embodiment, valve one 86 is provided on the water pipes entering the temperature control water jacket 11 and exiting the temperature control water jacket 11, and a short-circuit pipe is provided between the water pipes entering the temperature control water jacket 11 and exiting the temperature control water jacket 11, and valve two 87 is provided on the short-circuit pipe: when the temperature control water jacket 11 needs to be cooled down, the two valves one 86 are opened and the valve two 87 is closed, and the cooling water first enters the temperature control water jacket 11 and then enters the plate heat exchanger; when the temperature control water jacket 11 needs to be heated up, the two valves one 86 are closed and the valve two 87 is opened, and the cooling water directly enters the plate heat exchanger from the short-circuit pipe.

[0062] Embodiment 4:

[0063] In the prior art, two driving parts are generally required to provide driving energy for the white material and the black material respectively, and each raw material needs to use a multi-plunger pump in conjunction with a motor, a magnetic coupling, a pressure sensor and other equipment to achieve continuous feeding, resulting in a complex structure and high price of the feeding equipment, which is not conducive to the large-scale promotion of polyurethane foaming equipment.

[0064] For this reason, on the basis of any of the above embodiments, the high pressure metering pump 5 used in this embodiment is a Figure 3 The vertical single-plunger reciprocating high-pressure metering pump shown in the figure has a detailed structure Figures 6 to 8 As shown, Figures 6 to 8 The left side of the middle is up and the right side is down, specifically including:

[0065] A linear drive with its output end facing downward and two cylinder bodies 65 located below the linear drive. The piston rods 38 of the two cylinder bodies 65 are connected to the output end of the linear drive. The bottom of the piston rod 38 is connected to the first piston 37. The first piston 37 moves in the piston cavity. The cylinder body 65 includes an upper seat 40 and a base 27 distributed above and below. A raw material inlet 66 is provided on the base 27, and a raw material outlet 67 is provided on the upper seat 40. A bottom valve 31 is provided on the top of the base 27, and a sealing cover 33 is provided at the bottom of the piston cavity. The bottom valve 31 and the sealing cover 33 both include a one-way valve that can be conducted from bottom to top. There is a gap between the first piston 37 and the inner wall of the cylinder body 65, and a through hole 68 connected to the gap is provided on the first piston 37. A one-way piston seal 35 and a polytetrafluoroethylene pad 34 are provided on the outer circle of the first piston 37, such as Figure 6 As shown, the one-way piston seal 35 and the polytetrafluoroethylene pad 34 are both located below the through hole 68. The outer sides of the one-way piston seal 35 and the polytetrafluoroethylene pad 34 are in contact with the inner wall of the cylinder body 65. As shown in the figure, the top end of the first piston 37 is threadedly connected to the piston rod 38, and the bottom end of the first piston 37 is threadedly connected to the sealing cover 33; when the piston rod 38 moves, it drives the first piston 37, the sealing cover 33, the one-way piston seal 35, and the polytetrafluoroethylene pad 34 to perform linear reciprocating motion together.

[0066] Preferably, in this embodiment, the one-way valve structure inside the bottom valve 31 is as follows: a flow hole connected to the raw material inlet 66 is provided at the bottom of the bottom valve 31, and a first small ball 30 is movably arranged inside the bottom valve 31. The one-way valve structure inside the sealing member gland 33 is as follows: a channel is provided on the sealing member gland 33, the bottom end of the channel is connected to the top end of the bottom valve 31, and the top end of the channel is connected to the piston cavity; a second small ball 36 is movably arranged above the channel. In this embodiment, the first small ball 30 and the second small ball 36 are both steel balls.

[0067] Specific:

[0068] When the first piston 37 moves upward, the raw material enters from the raw material inlet, pushes open the first ball 30, enters the bottom valve 31, and enters the piston cavity after passing through the bottom valve 31; at this time, the second ball 36 moves upward synchronously with the sealing cover, and the second ball 36 keeps blocking the channel; when the first piston 37 moves downward, the raw material presses the first ball 30, so that it automatically blocks the flow hole at the bottom of the bottom valve; at the same time, the raw material in the piston cavity is squeezed, pushes open the second ball 36, enters the gap through the through hole on the side wall of the first piston and is discharged.

[0069] Preferably, a base screw plug 28 is provided at the bottom of the base 27, and an O-ring 29 is provided between the bottom valve 31 and the base 27 and the cylinder body 65. A bidirectional piston seal 32 is provided between the seal gland 33 and the inner wall of the cylinder body 65, and an O-ring 29 facing the seal gland 33 is provided at the bottom of the first piston 37. The top of the upper seat 40 is fixedly connected to the first fixed plate 47, and the linear drive member is fixed on the second fixed plate 53. The first fixed plate 47 is located below the second fixed plate 53, and the first fixed plate 47 and the second fixed plate 53 are fixedly connected through a plurality of columns 45; an upper seat gland 43 is provided between the first fixed plate 47 and the upper seat 40, a rod seal is slidably connected between the upper seat gland 43 and the piston rod 38, and an O-ring 29 is provided between the upper seat gland 43 and the upper seat 40; and a lubrication cup 44 is also provided above the upper seat gland 43, and the lubrication cup 44 is used to lubricate the piston rod 38. The inductive proximity switch 46 is also included. The inductive proximity switch 46 is used to sense whether the piston rod 38 reaches the two ends of the stroke.

[0070] In this embodiment, the tie rod seal includes a first tie rod seal 41 and a second tie rod seal 42 ; in addition, a third tie rod seal 57 is provided between the second fixing plate 53 and the piston rod of the second piston 60 for sliding fit and ensuring sealing.

[0071] Preferably, the linear drive member is a hydraulic cylinder, the output end of which is fixedly connected to the piston rods 38 of the two cylinder bodies 65 at the same time. The two cylinder bodies 65 are arranged side by side, and the axis of the hydraulic cylinder is parallel to the axis of the piston rod 38. The hydraulic cylinder includes a cylinder body 61, a cylinder seat 62 matching the cylinder body 61, and a second piston 60; the output end of the second piston 60 is fixedly connected to the piston rod 38 of the cylinder body 65. For a more detailed structural diagram of the hydraulic cylinder in this embodiment, please refer to Figure 8 .

[0072] The working principle of the high-pressure metering pump 5 of the present embodiment is as follows: the first stroke of the piston rod 38 of any cylinder body is a filling stroke, that is, the raw material fills the piston cavity and the inside of the gap. Starting from the second stroke, the first piston 37 moves upward first, pushing the raw material between the piston rod 38 and the inner wall of the cylinder body upward, and discharges it from the raw material outlet; at the same time, the raw material is sucked in from the raw material inlet on the base, passes through the one-way valve in the bottom valve and enters the piston cavity for raw material replenishment to ensure that the piston cavity is always full of raw materials; when the first piston 37 moves upward to the top of the stroke, it changes direction and moves downward. At this time, the one-way valve in the bottom valve is in a closed state, and the one-way valve in the sealing cover is opened, that is, the raw material in the piston cavity pushes open the one-way valve in the sealing cover and enters the first piston 37, and then enters the gap through the through hole on the side wall of the first piston 37, so that the raw material passes through the space between the piston rod 38 and the cylinder body and is finally discharged from the raw material outlet located above.

[0073] Embodiment 5:

[0074] Different from Example 4, the high-pressure metering pump 5 used in this embodiment is as follows Figure 2 The horizontal structure shown in FIG. Fig. 9 and Fig.10 As shown: it includes a horizontal linear drive member, each of the opposite ends of the linear drive member has an output end, and also includes a main cylinder body 85 located on both sides of the linear drive member, the two output ends are respectively connected to the piston rods 38 of the two main cylinder bodies 85, the piston of the main cylinder body 85 is slidably sealed with the inner wall of the main cylinder body 85, and there is a gap between the piston rod 38 of the main cylinder body 85 and the inner wall of the main cylinder body 85; the end of the main cylinder body 85 away from the linear drive member is connected to the base 27, the bottom of the base 27 is a feed connector 69, and the top of the base 27 is a valve seat 72, the feed connector 69 and the valve seat 72 are both provided with a one-way valve that conducts from bottom to top, the valve seat 72 is also connected to the auxiliary cylinder body 75, and the auxiliary cylinder body 75 is located above the corresponding main cylinder body 85; the auxiliary cylinder body 75 is also connected to the upper seat 40, the bottom of the upper seat 40 is connected to the main cylinder body 85, and the top of the upper seat 40 is provided with a raw material outlet 67. In this embodiment, the volume of the auxiliary cylinder body is smaller than that of the main cylinder body, and the connection point between the upper seat and the main cylinder body is located at an end of the main cylinder body away from the base.

[0075] When the present embodiment is used, the first stroke of the piston rod of any main cylinder 85 is the filling stroke, specifically: the linear drive member drives the piston rod of the main cylinder 85 to contract in the direction of the linear drive member to suck the raw material, the raw material enters the feed joint through the one-way valve in the feed joint, and then enters the main cylinder 85 to fill the main cylinder 85, then the linear drive member drives the piston rod of the main cylinder 85 to move in the direction away from the linear drive member, and the piston of the main cylinder 85 pushes the raw material outward, due to the presence of the one-way valve in the feed joint, the raw material can only enter the auxiliary cylinder 75 through the one-way valve in the valve seat, after filling the auxiliary cylinder 75, the raw material continues to be discharged outward, and under the action of gravity, it will not be discharged through the raw material outlet 67, but will flow back downward through the upper seat to the main cylinder 85, filling the gap between the piston rod of the main cylinder 85 and the inner wall of the main cylinder 85, at this time, the initial stroke, i.e., the filling stroke, is completed, and the raw material fills the auxiliary cylinder 75 and the inside of the gap. Each stroke from the second stroke cycle is as follows: the linear drive drives the piston rod of the main cylinder 85 to contract and suck the raw material in the direction of the linear drive. Due to the movement of the piston of the main cylinder 85, the raw material between the piston rod and the inner wall of the main cylinder 85 is squeezed back to the upper seat direction. Since the auxiliary cylinder 75 is filled with raw materials and there is a one-way valve in the valve seat, the raw material cannot continue to flow back to the auxiliary cylinder 75 and can only be discharged through the raw material outlet 67 at the top of the upper seat. During this process, the piston of the main cylinder 85 simultaneously sucks new raw materials from the feed joint into the main cylinder 85. After that, the linear drive drives the piston rod of the main cylinder 85 to move away from the linear drive, pushing all the raw materials in the main cylinder 85 toward the auxiliary cylinder 75. Since the auxiliary cylinder 75 itself is in a filled state, the raw materials in the main cylinder 85 are pushed into the newly formed gap after entering, and the remaining raw materials are all discharged from the raw material outlet 67.

[0076] Preferably, a plurality of bidirectional piston seals 32 are sleeved on the piston of the main cylinder body 85, and the bidirectional piston seals 32 are in contact with the inner wall of the main cylinder body 85. The one-way valve structure corresponding to the feed connector 69 is as follows: a third small ball 70 is movably arranged inside the base 27; when there is no external force, the third small ball 70 blocks the top of the feed connector 69 under the action of gravity; the base 27 also includes a ball baffle 71 fixedly arranged above the third small ball 70. The one-way valve structure corresponding to the valve seat 72 is as follows: the valve seat 72 is fixed inside the base 27, a flow hole is provided at the bottom of the valve seat 72, and a fourth small ball 73 is movably arranged inside the valve seat 72; when there is no external force, the fourth small ball 73 blocks the flow hole under the action of gravity; the top of the valve seat 72 is blocked by a plug 74. The linear drive member is a double-rod hydraulic cylinder, and the two ends of the double-rod hydraulic cylinder are each fixed to a cylinder fixing plate 79; the cylinder fixing plates 79 on both sides are respectively fixedly connected to the upper seat 40 in the corresponding direction through a plurality of columns 45. A proximity switch 77 is provided on the column 45, and the proximity switch 77 is used to sense the stroke of the double-rod hydraulic cylinder.

[0077] Preferably, each upper seat 40 is provided with a matching upper seat cover 43, and the upper seat cover 43 presses the corresponding upper seat 40 onto the end of the main cylinder 85. The upper seat 40 is provided with a lubrication cup 44, and the lubrication cup 44 is located at one end of the upper seat 40 away from the corresponding main cylinder 85; the lubrication cup 44 is used to lubricate the corresponding piston rod 38. The axes of the two main cylinders 85 are collinear; the main cylinder 85 is parallel to the axis of the corresponding sub-cylinder 75. The feed connector is an end straight connector, and the raw material outlet 67 is also provided on an end straight connector.

[0078] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In addition, the term "connected" used in this article can be directly connected or indirectly connected via other components without special explanation.

[0079] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A cyclopentane foaming device, comprising a white material tank (9), a black material tank (7), and a mixing head (22) for polyurethane foaming, characterized in that: It also includes a high-pressure metering pump (5), which is used to pump the white material and the black material to the mixing head (22) respectively; the pipelines for the high-pressure metering pump (5) to pump the white material and the black material are both connected to the energy accumulator (19), wherein the back pressure of the energy accumulator (19) on the pipeline for pumping the white material is greater than the back pressure of the energy accumulator (19) on the pipeline for pumping the black material; the white material tank (9), the black material tank (7), and the high-pressure metering pump (5) are all located in an airtight enclosure, and an explosion-proof system is provided in the airtight enclosure; The energy accumulator (19) is an airbag type energy accumulator, wherein the inflation pressure of the energy accumulator (19) on the pipeline for pumping white material is 0.5-3 MPa greater than the inflation pressure of the energy accumulator (19) on the pipeline for pumping black material; The high-pressure metering pump (5) comprises a driving member (23), wherein the driving member (23) is used to drive a white material metering cylinder (24) and a black material metering cylinder (25) to operate simultaneously, wherein the white material metering cylinder (24) pumps white material from a white material tank (9), and the black material metering cylinder (25) pumps black material from a black material tank (7); The high-pressure metering pump (5) is a vertical high-pressure metering pump or a horizontal high-pressure metering pump; The vertical high-pressure metering pump comprises a driving member with an output end facing downward, and two cylinder bodies (65) located below the driving member, the two cylinder bodies (65) being a white material metering cylinder and a black material metering cylinder respectively; the piston rods (38) of the two cylinder bodies (65) are both connected to the output end of the driving member, the bottom of the piston rod (38) is connected to a first piston (37), and the first piston (37) moves in a piston cavity; the cylinder body (65) comprises an upper seat (40) and a base (27) arranged at the upper and lower parts, a raw material inlet (66) being provided on the base (27), and a raw material outlet (67) being provided on the upper seat (40); a bottom valve (31) is provided on the top of the base (27), and a sealing member gland (33) is provided at the bottom of the piston cavity, the bottom valve (31) and the sealing member gland (33) both comprising a one-way valve capable of conducting from bottom to top; a gap is provided between the first piston (37) and the inner wall of the cylinder body (65), and a through hole (68) communicating with the gap is provided on the first piston (37); The horizontal high-pressure metering pump comprises a horizontally placed driving member, each of the driving member having an output end at opposite ends, and also comprises a main cylinder body (85) located on both sides of the driving member, the two output ends being respectively connected to the piston rods (38) of the two main cylinder bodies (85), the two main cylinder bodies (85) being respectively a white material metering cylinder and a black material metering cylinder; the piston of the main cylinder body (85) is slidably sealed against the inner wall of the main cylinder body (85), a gap is provided between the piston rod (38) of the main cylinder body (85) and the inner wall of the main cylinder body (85); the main cylinder body (85) is away from the straight line One end of the driving member is connected to the base (27). The bottom of the base (27) is a feed connector (69). The top of the base (27) is a valve seat (72). Both the feed connector (69) and the valve seat (72) are provided with a one-way valve that conducts from bottom to top. The valve seat (72) is also connected to a sub-cylinder body (75). The sub-cylinder body (75) is located above the corresponding main cylinder body (85). The sub-cylinder body (75) is also connected to the upper seat (40). The bottom of the upper seat (40) is connected to the main cylinder body (85). The top of the upper seat (40) is provided with a raw material outlet (67).

2. A cyclopentane foaming device according to claim 1, characterized in that, The volume of the white material metering cylinder (24) is smaller than the volume of the black material metering cylinder (25).

3. A cyclopentane foaming device according to claim 1, characterized in that, The driving member (23) is a hydraulic cylinder and also includes a hydraulic station (4) matching the hydraulic cylinder. The pipeline from the hydraulic cylinder to the hydraulic station (4) is connected to a heat dissipation device (18), and the heat dissipation device (18) uses a chiller (20) as a cold source.

4. A cyclopentane foaming device according to claim 1, characterized in that: The explosion-proof system comprises a detection probe (17) for detecting the concentration of cyclopentane and a fan for exhausting the gas in the airtight enclosure, wherein the fan is controlled by a detection signal from the detection probe (17); the airtight enclosure and all equipment in the airtight enclosure are grounded.

5. A cyclopentane foaming device according to claim 4, characterized in that: The fan comprises a primary fan and a secondary fan, the power of the secondary fan being greater than the power of the primary fan; when the detection probe (17) detects that the concentration of cyclopentane reaches 20% of the lower explosion limit, the primary fan is started; when the detection probe (17) detects that the concentration of cyclopentane reaches 40% of the lower explosion limit, the secondary fan is started.

6. A cyclopentane foaming device according to claim 1, characterized in that: The white material tank (9) and the black material tank (7) are both covered with a temperature-controlled water jacket (11), and also include a constant temperature element (13) for adjusting the temperature of the temperature-controlled water jacket (11).

7. A cyclopentane foaming device according to claim 1, characterized in that: The white material tank (9) and the black material tank (7) are both provided with a stirrer (8), a pressure reducing valve (6), and a feeding pump (12). Inert gas is filled in the white material tank (9) and the black material tank (7). The feeding pump (12) is used for automatically feeding the corresponding material tank.

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