A multifunctional environmentally friendly and energy-saving polyurethane high-pressure foaming machine and metering method

Abstract

The present invention discloses a multifunctional environmentally friendly and energy-saving polyurethane high-pressure foaming machine, comprising a mixing head, wherein the mixing head is connected to two feeding systems, each feeding system comprises a material barrel, a material supply and return device is installed in the material barrel, the material supply and return device is connected to a feeding pump via a first pipe, the feeding pump is connected to a heat exchanger via a second pipe, the heat exchanger is connected to a three-way steering valve via a third pipe, one of the interfaces of the three-way steering valve is connected to a metering pump via a fourth pipe, the metering pump is connected to the feeding interface of the mixing head via a fifth pipe, the other interface of the three-way steering valve is connected to the feeding and return device via a sixth pipe, and the return interface of the mixing head is connected to the sixth pipe via a seventh pipe. The advantages of the present invention are: the storage tank, high-low pressure conversion valve, measuring valve and flow meter in the prior art are eliminated, and production suspension due to damage to the high-low pressure conversion valve, measuring valve and flow meter is avoided during use, which not only saves costs but also extends the service life of the equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of polyurethane production equipment, in particular to a multifunctional environmentally friendly and energy-saving polyurethane high-pressure foaming machine and a metering method. Background Art

[0002] At present, with the continuous improvement of people's living standards, polyurethane foam materials are widely used in many fields such as production and life, such as polyurethane high-speed rail sleepers, polyurethane wind turbine blades, polyurethane tank wheels, polyurethane automotive interior parts, polyurethane exterior wall insulation, polyurethane composite instrument panels, polyurethane furniture, polyurethane pillows and polyurethane tires. In these industries, the production equipment of polyurethane foam materials used mostly adopts polyurethane foaming equipment that mixes with stirring or air blowing. The polyurethane high-pressure foaming machine in the prior art is connected to the high-pressure metering pump of the main machine through a high-pressure hose at the filter outlet, and utilizes the high-speed atomization collision generated by the high pressure to fully mix the two groups of raw materials in the mixing head, inject them into the mold cavity, and foam them into shape. However, the polyurethane high-pressure foaming machine in the prior art has the following disadvantages:

[0003] 1. The high and low pressure conversion valves in the polyurethane high pressure foaming machine work frequently and have a short service life. They need to be replaced frequently.

[0004] 2. When producing products of different colors, the raw material storage tank needs to be cleaned;

[0005] 3. The overall equipment occupies a large space, has a long production cycle and high manufacturing costs. Summary of the Invention

[0006] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a multifunctional environmentally friendly and energy-saving polyurethane high-pressure foaming machine.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] The invention discloses a multifunctional environmentally friendly and energy-saving polyurethane high-pressure foaming machine, which includes a mixing head. The mixing head is connected to two feeding systems. Each feeding system includes a material barrel. A feeding and returning device is installed in the material barrel. The feeding and returning device is connected to a feeding pump through a first pipeline. The feeding pump is connected to a heat exchanger through a second pipeline. The heat exchanger is connected to a three-way steering valve through a third pipeline. One interface of the three-way steering valve is connected to a metering pump through a fourth pipeline. The metering pump is connected to a feeding interface of the mixing head through a fifth pipeline. The other interface of the three-way steering valve is connected to the feeding and returning device through a sixth pipeline. The returning interface of the mixing head is connected to the sixth pipeline through a seventh pipeline.

[0009] Preferably, an energy storage tank is installed on the second pipeline, and a one-way valve is installed on the second pipeline between the feed pump and the energy storage tank.

[0010] Preferably, the first pipe is equipped with a first filter, the fourth pipe is equipped with a second filter, and the fifth pipe is equipped with a third filter.

[0011] Preferably, a first pressure controller is installed on the fourth pipeline between the second filter and the metering pump, and a second pressure controller is installed on the fifth pipeline between the metering pump and the third filter.

[0012] Preferably, the heat exchanger includes two end heads, and a coaxially arranged inner tube, middle tube and outer tube are fixedly connected between the two end heads. A heating rod is installed in the inner tube, a feed channel is formed between the inner tube and the middle tube, and circulating water is installed between the outer tube and the middle tube. A connecting hole connected to the feed channel is provided on one side of each end head, one of the connecting holes is connected to the first pipe, and the other connecting hole is connected to the second pipe. A hot and cold circulation channel is formed between the middle tube and the outer tube, and two connecting tubes connected to the hot and cold circulation channel are provided on the outer tube.

[0013] Preferably, the material supply and return device includes a first base pipe, a fixed connecting ring is sleeved on the outside of the first base pipe, one side of the connecting ring is fixedly connected to the first sleeve, the first sleeve and the first base pipe are coaxially arranged, a first gap is formed between the first sleeve and the first base pipe, a joint pipe connected to the first gap is provided on one side of the first sleeve, the joint pipe is connected to the sixth pipeline, and the first base pipe is connected to the first pipeline.

[0014] Preferably, the barrel is equipped with a liquid level and temperature control device, which includes a second base tube, the outer side of the second base tube is threadedly connected to the second sleeve, a second gap is formed between the lower end of the second sleeve and the second base tube, and an inflation pipe connected to the second gap is provided on one side of the second sleeve, and the inflation pipe is connected to the gas storage tank.

[0015] Preferably, the metering pump is a metering pump equipped with a magnetic coupling.

[0016] Preferably, a second liquid level sensor is installed in the energy storage tank.

[0017] The metering method of the above-mentioned multifunctional environmentally friendly and energy-saving polyurethane high-pressure foaming machine determines the discharge amount of the metering pump per revolution by measuring the single-component flow rate in one second through the mixing head; determines the unit discharge amount of the metering pump per unit time based on the total discharge amount; and adjusts the speed of the metering pump through the PLC controller. The total discharge amount per unit time can be adjusted according to the speed of the metering pump.

[0018] The advantages of the present invention are that it eliminates the high and low pressure conversion valves, measuring valves and flow meters in the prior art, and avoids the normal operation of the conversion valve due to wear of these parts or crystallization of raw materials, which may lead to production stoppage in severe cases. It can not only extend the service life of the equipment, but also realize continuous production operation. It eliminates the measuring valves and flow meters in the prior art, and avoids the flow meter from being blocked or worn during operation and affecting the measurement accuracy. There is no large storage tank in the overall equipment, and the overall equipment is directly used with the material tanks produced by the manufacturer. When producing products of different colors, the material barrels can be directly replaced without cleaning, reducing the workload of the operator. The overall equipment occupies a small space. During the use of cyclopentane foaming agent, only a very small isolation room is needed to accommodate the use of this equipment. Adding an air pipe above the mixing head discharge nozzle can directly use it as a high-viscosity raw material sprayer. When used as a high-viscosity raw material sprayer, it can be used to produce automobile spare tire isolation plates, thereby realizing the versatility of the equipment. Adding three filters in the process can make the pressure of the mixture more stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the process flow chart of a multifunctional, environmentally friendly and energy-saving polyurethane high-pressure foaming machine;

[0020] Figure 2 This is the basic structural diagram of the material supply and return device;

[0021] Figure 3 This is the basic structure diagram of the heat exchanger;

[0022] Figure 4 yes Figure 3 A magnified view of part A;

[0023] Figure 5 It is the basic structural diagram of the liquid level and temperature control device. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0025] Example 1

[0026] The present embodiment provides a multifunctional environmentally friendly and energy-saving polyurethane high-pressure foaming machine, including a mixing head 6, which is connected to two feeding systems, each of which includes a barrel 1, a feeding and returning device 8 installed in the barrel 1, and the feeding and returning device 8 is connected to the feeding pump 2 through a first pipe 11, a first filter 100 is installed on the first pipe 11, the feeding pump 2 is connected to the heat exchanger 3 through a second pipe 12, an energy storage tank 9 is installed on the second pipe 12, a second liquid level sensor is installed in the energy storage tank 9, a one-way valve 400 is installed on the second pipe 12 between the feeding pump 2 and the energy storage tank 9, the heat exchanger 3 is connected to the three-way steering valve 4 through a third pipe 13, and one of the three-way steering valves 4 is connected to the heat exchanger 3. The interface is connected to the metering pump 5 through a fourth pipe 14, a second filter 200 is installed on the fourth pipe 14, a first pressure controller 500 is installed on the fourth pipe 14 between the second filter 200 and the metering pump 5, the metering pump 5 is a metering pump equipped with a magnetic coupling, the metering pump 5 is connected to the feed interface of the mixing head 6 through a fifth pipe 15, a third filter 300 is installed on the fifth pipe 15, a second pressure controller 600 is installed on the fifth pipe 15 between the metering pump 5 and the third filter 300, the other interface of the three-way steering valve 4 is connected to the feed and return device 8 through a sixth pipe 16, and the return interface of the mixing head 6 is connected to the sixth pipe 16 through a seventh pipe 17.

[0027] Specifically, the heat exchanger 3 includes two end heads 34, and the two end heads 34 are fixedly connected to the coaxially arranged inner tube 31, middle tube 32, and outer tube 33. A heating rod is installed in the inner tube 31, and a feed channel is formed between the inner tube 31 and the middle tube 32. Each end head 34 is provided with a connecting hole 36 connected to the feed channel on one side, one of the connecting holes 36 is connected to the first pipe 11, and the other connecting hole 36 is connected to the second pipe 12. A hot and cold circulation channel is formed between the middle tube 32 and the outer tube 33. Two connecting pipes 35 connected to the hot and cold circulation channels are provided on the outer tube 33, and a circulating water pipe is installed between the two connecting pipes 35.

[0028] Specifically, the feed and return device 8 includes a first base pipe 81, a fixed connecting ring 82 is sleeved on the outer side of the first base pipe 81, and one side of the connecting ring 82 is fixedly connected to the first sleeve 83. The first sleeve 83 is coaxially arranged with the first base pipe 81, and a first gap 84 is formed between the first sleeve 83 and the first base pipe 81. A joint pipe 85 connected to the first gap 84 is provided on one side of the first sleeve 83. The joint pipe 85 is connected to the sixth pipeline 16, and the first base pipe 81 is connected to the first pipeline 11.

[0029] Specifically, the barrel 1 is equipped with a liquid level and temperature control device 7, which includes a second base tube 71. The second base tube 71 is equipped with a first liquid level sensor and a temperature detector. The outer side of the second base tube 71 is threadedly connected to the second sleeve 72. A second gap 73 is formed between the lower end of the second sleeve 72 and the second base tube 71. An inflation pipe 74 connected to the second gap 73 is provided on one side of the second sleeve 72, and the inflation pipe 74 is connected to the gas storage tank.

[0030] Continuously fill the barrel 1 with nitrogen to prevent negative pressure from occurring in the barrel 1, and at the same time effectively prevent the volatilization of the polyether composition foaming agent and the crystallization of the isocyanate. When the temperature in the barrel 1 is too low, the three-way diverter valve 4 is connected to the sixth pipe 16, and the raw material in the barrel 1 is pressurized by the feed pump 2. After being heated by the heat exchanger 3, it is returned to the barrel 1, so as to continuously heat or cool the raw material in the barrel 1. When the temperature in the barrel 1 rises or drops, the three-way diverter valve 4 is diverted and connected to the fourth pipe 14 to control the temperature in the barrel. The raw material in the barrel 1 is pressurized by the metering pump 5 and enters the mixing head 6. When discharging, the two raw materials are mixed in the mixing head 6 and discharged. When the material is discharged, the raw material passes through the seventh pipe 17 and the sixth pipe 16 and returns to the barrel 1. The accumulator tank 9 can temporarily store part of the raw material, so as to ensure that there is always raw material available at the mixing head 6. The accumulator tank 9 is equipped with a liquid level sensor, and the liquid level sensor controls the feed pump 2 through the PLC controller.

[0031] Example 2

[0032] This embodiment discloses a metering method for a multifunctional, environmentally friendly, and energy-saving polyurethane high-pressure foaming machine. The method comprises determining the discharge volume per revolution of a metering pump by measuring the single-component flow rate per second obtained by a mixing head; determining the discharge volume per revolution of the metering pump; and determining the unit discharge volume of the metering pump per unit time based on the total discharge volume. The metering pump is driven by a servo motor or a variable frequency motor, and the speed of the servo motor is controlled by a PLC or the speed of the variable frequency motor is changed by a frequency converter, thereby changing the speed of the metering pump. The total discharge volume per unit time can be adjusted based on the speed of the metering pump.

Claims

1. A multifunctional environmentally friendly and energy-saving polyurethane high-pressure foaming machine, characterized by: The invention comprises a mixing head (6), wherein the mixing head (6) is connected to two feeding systems, each of the feeding systems comprises a barrel (1), wherein a feeding and returning device (8) is installed in the barrel (1), wherein the feeding and returning device (8) is connected to a feeding pump (2) via a first pipe (11), wherein the feeding pump (2) is connected to a heat exchanger (3) via a second pipe (12), wherein the heat exchanger (3) is connected to a three-way steering valve (4) via a third pipe (13), wherein one interface of the three-way steering valve (4) is connected to a metering pump (5) via a fourth pipe (14), wherein the metering pump (5) is connected to a feeding interface of the mixing head (6) via a fifth pipe (15), wherein another interface of the three-way steering valve (4) is connected to the feeding and returning device (8) via a sixth pipe (16), and wherein a returning interface of the mixing head (6) is connected to the sixth pipe (16) via a seventh pipe (17); An energy storage tank (9) is installed on the second pipeline (12), and a one-way valve (400) is installed on the second pipeline (12) between the feed pump (2) and the energy storage tank (9); The first pipe (11) is equipped with a first filter (100), the fourth pipe (14) is equipped with a second filter (200), and the fifth pipe (15) is equipped with a third filter (300); A first pressure controller (500) is installed on the fourth pipe (14) between the second filter (200) and the metering pump (5), and a second pressure controller (600) is installed on the fifth pipe (15) between the metering pump (5) and the third filter (300); The heat exchanger (3) comprises two end heads (34), wherein a coaxially arranged inner tube (31), a middle tube (32), and an outer tube (33) are fixedly connected between the two end heads (34), a heating rod is installed in the inner tube (31), a feed channel is formed between the inner tube (31) and the middle tube (32), and a connecting hole (36) connected to the feed channel is provided on one side of each end head (34), wherein one of the connecting holes (36) is connected to the first pipe (11), and the other connecting hole (36) is connected to the second pipe (12), a heat circulation channel is formed between the middle tube (32) and the outer tube (33), and two connecting tubes (35) connected to the heat circulation channel are provided on the outer tube (33); The feeding and returning device (8) includes a first base tube (81), a fixed connecting ring (82) is sleeved on the outer side of the first base tube (81), one side of the connecting ring (82) is fixedly connected to a first sleeve (83), the first sleeve (83) and the first base tube (81) are coaxially arranged, a first gap (84) is formed between the first sleeve (83) and the first base tube (81), a joint pipe (85) connected to the first gap (84) is provided on one side of the first sleeve (83), the joint pipe (85) is connected to the sixth pipeline (16), and the first base tube (81) is connected to the first pipeline (11); The material barrel (1) is provided with a liquid level and temperature control device (7), the liquid level and temperature control device (7) comprising a second base tube (71), a first liquid level sensor and a temperature detector being provided in the second base tube (71), the outer side of the second base tube (71) being threadedly connected to a second sleeve tube (72), a second gap (73) being formed between the lower end of the second sleeve tube (72) and the second base tube (71), an air filling tube (74) being provided on one side of the second sleeve tube (72) and communicating with the second gap (73), and the air filling tube (74) being connected to a gas storage tank; The metering pump (5) is a metering pump equipped with a magnetic coupling; A second liquid level sensor is installed in the energy storage tank (9); The discharge volume of the metering pump per revolution is determined by measuring the single-component flow rate per second obtained by the mixing head; the unit discharge volume of the metering pump per unit time is determined based on the total discharge volume; the speed of the metering pump is adjusted by the PLC controller, and the total discharge volume per unit time can be adjusted according to the speed of the metering pump.

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