Waterborne polyurethane acetone desolventizing and recycling device

Abstract

The utility model discloses a waterborne polyurethane acetone desolventizing and recycling device, and relates to the technical field of polyurethane production equipment. The device comprises a desolventizing kettle, a recovery tank is arranged on one side of the desolventizing kettle, a three-way regulating valve and a weightometer are sequentially installed between the desolventizing kettle and the recovery tank, a discharging pump is installed on one side of the recovery tank, a flow meter is installed on one side of the discharging pump, and the weightometer is electrically connected with the three-way regulating valve, the discharging pump and the flow meter. And a vacuum pump is mounted on one side between the desolventizing kettle and the recovery tank. The three-way regulating valve and the weightometer are sequentially mounted between the desolventizing kettle and the recovery tank, the discharge pump with the flow meter is mounted on one side of the recovery tank, and the opening value of the three-way regulating valve is controlled by monitoring the difference between the weightometer and the flow meter, so that the device can continuously recover acetone and reduce the loss of pure water in the desolventizing kettle at the same time.

Description

TECHNICAL FIELD

[0001] The utility model belongs to polyurethane production equipment technical field, specifically, especially relate to a waterborne polyurethane acetone desolventizing recovery device. BACKGROUND

[0002] Waterborne polyurethane is widely used in various products due to its excellent foaming property, no pollution, excellent aging resistance and adjustable molecular weight, wherein the molecular weight of polyurethane foaming material is required to be high to meet its foaming property, water resistance and heat resistance.

[0003] The utility model discloses a kind of desolventizing devices for waterborne polyurethane emulsion, including kettle body, still including multiple steam pipes, desolventizing cavity and solvent recovery tank, at least one steam pipe bottom is provided with necking head, remaining steam pipe is provided with steam collecting cover;First screen body is arranged in the inner side of steam collecting cover;Desolventizing cavity includes closed cavity, closed cavity includes large semicircle cavity and small semicircle cavity, necking section is arranged between large semicircle cavity and small semicircle cavity;The same number of connecting pipe sections as steam pipe is integrally made in closed cavity bottom;Connecting pipe section and steam pipe are sealedly connected by flange;

[0004] Since the desolventizing kettle will take out the internal pure water with acetone to the recovery tank during desolventizing, and the part of pure water is lost with the recovery action of the recovery tank, therefore, the scheme is to set the desolventizing cavity at the top end of the desolventizing kettle, expand the steam pipe, and liquefy and enrich the pure water vapor taken out when the desolventizing kettle discharges crude acetone, so as to avoid the loss of pure water in the desolventizing kettle. However, the desolventizing process of this device always maintains a constant production speed, but the recovery tank needs to discharge acetone in time after collecting a certain amount of acetone, and during the process of discharging acetone, the desolventizing kettle working at the original discharge speed cannot enrich and recover all the pure water through the desolventizing cavity, which leads to the loss of pure water. That is, the existing recovery device cannot control the discharge process of the desolventizing kettle side when collecting acetone, which leads to the loss of pure water.

[0005] At present, there is no effective solution to the problems in the related technology. INVENTION CONTENTS

[0006] The utility model discloses a kind of waterborne polyurethane acetone desolventizing recovery devices, and the technical problems to be solved are as follows: the existing polyurethane acetone desolventizing recovery device cannot control desolventizing process when using, which leads to the loss of internal pure water.

[0007] The purpose of the utility model can be realized by the following technical solutions:

[0008] The utility model provides an aqueous polyurethane acetone desolventizing recovery device, including desolventizing kettle, one side of desolventizing kettle is provided with recovery tank, three -way regulating valve and weighing meter are installed gradually between desolventizing kettle with recovery tank, one side of recovery tank is installed with discharge pump, one side of discharge pump is installed with flowmeter, weighing meter with three -way regulating valve, discharge pump and flowmeter all are electrically connected, and vacuum pump is installed between desolventizing kettle with recovery tank on one side.

[0009] As a further scheme of the utility model: the desolventizing kettle top one side is equipped with inlet valve one, the recovery tank one side is equipped with inlet valve two, the inlet valve one and the inlet valve two all are connected with nitrogen supply system.

[0010] As a further scheme of the utility model: the desolventizing kettle top is equipped with stirring motor, and one side is equipped with temperature control system.

[0011] As a further scheme of the utility model: the desolventizing kettle one side is equipped with exhaust valve, and the other side is equipped with vacuum regulating valve.

[0012] As a further scheme of the utility model: the weighing meter measurement value is the difference of inlet flow and outlet flow of flowmeter.

[0013] As a further scheme of the utility model: the discharge pump starting operation is controlled by the measurement value, the opening of three -way regulating valve is inversely related with the measurement value, the opening of three -way regulating valve is adjusted as periodical circulation adjustment, and keeps normally open state.

[0014] The utility model has the advantages of:

[0015] Through installing three -way regulating valve between desolventizing kettle and recovery tank, and installing weighing meter on the side of recovery tank receiving acetone in desolventizing kettle, installing flowmeter on the side of discharge pump of recovery tank, and electrically connecting weighing meter with discharge pump, flowmeter and three -way regulating valve, when using, with the acetone received by recovery tank gradually increasing, discharge pump starts discharging acetone when flowmeter reaches predetermined high value, and three -way regulating valve reduces opening to delay the discharge of desolventizing kettle, until the difference between weighing meter and flowmeter reaches predetermined low value, three -way regulating valve restores opening, and discharge pump is closed, so that the periodic discharge of acetone in recovery tank is realized, and the continuous production function of acetone recovery is realized.

[0016] Further, since the three-way regulating valve is in a low opening state when the acetone is discharged into the recovery tank, the desolventizing kettle is continuously fed, the pure water inside is reused by the new material, and the discharge efficiency is also reduced, and when the three-way regulating valve restores the opening, the recovery tank no longer discharges acetone, so that the pure water in the desolventizing kettle is efficiently utilized throughout the entire production process, and is not easy to be discharged, and the technical advantage is that by controlling the discharge rhythm of the recovery tank and the opening of the three-way regulating valve, the equipment realizes continuous production while greatly reducing the pure water loss in the desolventizing kettle. BRIEF DESCRIPTION OF DRAWINGS

[0017] The utility model will be further described below in combination with the drawings.

[0018] Fig. 1 It is the whole structure schematic diagram of the utility model;

[0019] Fig. 2 It is the structure schematic diagram of the desolventizing kettle of the utility model;

[0020] Fig. 3 It is the structure schematic diagram of the three-way regulating valve of the utility model;

[0021] Fig. 4 It is the structure schematic diagram of the recovery tank of the utility model.

[0022] In the drawing: 1, desolventizing kettle;2, stirring motor;3, temperature control system;4, exhaust valve;5, vacuum pump;6, three-way regulating valve;7, vacuum regulating valve;8, recovery tank;9, weighing meter;10, discharge pump;11, flow meter;12, inlet valve one;13, inlet valve two. DETAILED DESCRIPTION

[0023] The technical scheme in the embodiments of the utility model will be clearly and completely described below in combination with the drawings in the embodiments of the utility model, and obviously, the described embodiments are only part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the utility model.

[0024] As Figs. 1 to 4As shown, a water-based polyurethane acetone desolventizing recovery device includes a desolventizing kettle 1, a recovery tank 8 arranged on one side of the desolventizing kettle 1, a three-way regulating valve 6 and a weighing meter 9 arranged in sequence between the desolventizing kettle 1 and the recovery tank 8, a discharge pump 10 arranged on one side of the recovery tank 8, a flow meter 11 arranged on one side of the discharge pump 10, the weighing meter 9 being electrically connected with the three-way regulating valve 6, the discharge pump 10 and the flow meter 11, and a vacuum pump 5 arranged on one side between the desolventizing kettle 1 and the recovery tank 8; the vacuum pump 5 is first connected with the recovery tank 8, and the recovery tank 8 is connected with the desolventizing kettle 1; in the desolventizing preparation stage, the desolventizing kettle 1 and the recovery tank 8 are vacuumized by the vacuum pump 5, so as to reduce the boiling point of acetone in the desolventizing kettle 1, avoid the thermal-sensitive water-based polyurethane from being degraded and gel produced at high temperature, accelerate the solvent evaporation efficiency, and clean the recovery environment in the recovery tank 8 to avoid the finished product from being contacted with air.

[0025] An air inlet valve one 12 is arranged on one side of the top end of the desolventizing kettle 1, and an air inlet valve two 13 is arranged on one side of the recovery tank 8; the air inlet valve one 12 and the air inlet valve two 13 are connected with a nitrogen supply system; in the process of recovering acetone, the inside of the desolventizing kettle 1 and the recovery tank 8 are in a negative pressure state; after the recovery is completed, in order to avoid the risk of sudden pressure relief and the pollution of the inside of the tank body caused by vacuum back suction, the two tanks need to be restored to the normal pressure level; the conventional air is a pollution source, so a nitrogen back flushing pipeline needs to be externally connected to supply nitrogen, so as to maintain the pressure relief safety and the cleanliness of the inside of the desolventizing kettle 1, and facilitate the subsequent production again.

[0026] A stirring motor 2 is arranged on the top end of the desolventizing kettle 1, and a temperature control system 3 is arranged on one side; after the desolventizing kettle 1 is filled, the inside temperature needs to be adjusted to a temperature suitable for acetone desolventizing, and the negative pressure state in the desolventizing kettle 1 at this time, that is, under the condition of 30 degrees and vacuum environment, the acetone as a solvent can be efficiently evaporated and recovered under the action of the water-based polyurethane.

[0027] An exhaust valve 4 is arranged on one side of the desolventizing kettle 1, and a vacuum regulating valve 7 is connected on the other side; when the desolventizing kettle 1 is filled, the exhaust valve 4 connected with the desolventizing kettle 1 is opened to discharge the nitrogen in the desolventizing kettle 1, so as to reduce the subsequent vacuumizing pressure; the vacuum regulating valve 7 controls the air pressure in the desolventizing kettle 1 to a suitable pressure value by adjusting the opening degree and cooperating with the vacuum pump 5 to perform the air suction action on the desolventizing kettle 1, which is an emergency pressure relief port for preventing the overpressure fault in the desolventizing kettle 1.

[0028] The weighing meter 9 measures the difference between the inflow and the outflow of the flow meter 11; the opening and closing of the discharge pump 10 are controlled by the weighing meter 9; the opening degree of the three-way regulating valve 6 is inversely related to the size of the difference; and the opening degree of the three-way regulating valve 6 is periodically adjusted.

[0029] During the transmission of acetone from the desolventizing kettle 1 to the recovery tank 8, the amount of acetone in the recovery tank 8 gradually increases, and the transmission amount is statistically measured by the weighing meter 9; at this time, since the discharge pump 10 is in a closed state, the flow meter 11 has no outflow amount, so the display value of the weighing meter 9 is the measurement value of the amount of acetone in the recovery tank 8; when the content of the recovery tank 8 reaches the maximum limit, the measurement value also reaches the set high limit interlocking value, at this time, the three-way regulating valve 6 connected with the weighing meter 9 is opened, the discharge pump 10 is opened, and the flow meter 11 measures the discharge amount; at this time, the recovery tank 8 is discharged due to the large outflow and small inflow, so the measurement value of the weighing meter 9 gradually decreases until the preset low limit interlocking value is reached, the opening degree of the three-way regulating valve 6 is restored, and the discharge pump 10 is closed, so that the acetone in the recovery tank 8 is discharged in stages, and the purpose is to maintain the sustainability of acetone recovery.

[0030] In addition, since the discharge pump 10 is opened at the same time, the pure water vapor in the desolventizing kettle 1 is also taken away, and since the three-way regulating valve 6 is in a low opening state at this time, the flow of pure water vapor in the desolventizing kettle 1 is reduced during acetone recovery, thereby achieving the function of reducing the loss rate of pure water, and it should be noted that the three-way regulating valve 6 is always in an open state, only a temporary low opening degree occurs, so as to avoid the speed reduction of the recovery process and improve the recovery efficiency, and the amount of pure water vapor lost in this stage is small and does not affect the recovery efficiency.

[0031] The working principle of the utility model:

[0032] Firstly, the water-based polyurethane material to be desolventized is transferred into the desolventizing kettle 1, then the stirring motor 2 and the temperature control system 3 are started to control the temperature of the desolventizing body and start to gradually increase the temperature, at the same time, the exhaust valve 4 is closed and the vacuum pump 5 is started to prepare for desolventization, then the three-way regulating valve 6 and the vacuum regulating valve 7 are opened, the opening degree is adjusted according to the liquid level and pressure in the desolventizing kettle 1, when the pressure in the desolventizing kettle 1 reaches the desolventization timing pressure 90Kpa, the three-way regulating valve 6 and the vacuum regulating valve 7 are opened to the maximum opening degree, at this time, the acetone in the desolventizing kettle 1 enters the inside of the recovery tank 8, and when it enters the inside of the recovery tank 8, the weighing meter 9 connected with the recovery tank 8 carries out the weighing of the feeding, when the total weight of the discharge measured by the weighing meter 9 reaches the high limit interlocking value, the three-way regulating valve 6 electrically connected with the weighing meter 9 is lowered in opening degree, at the same time, the discharge pump 10 electrically connected with the weighing meter 9 is opened, at this time, the feeding speed in the recovery tank 8 is lower than the discharging speed, at this time, the opening degree of the three-way regulating valve 6 is lowered, which can firstly avoid that a large amount of pure water vapor is discharged with the discharge pump 10 when the acetone is recovered, secondly, the loss of the pure water in the desolventizing kettle 1 is reduced, thirdly, the production process can be recorded and the production process is clear, and finally, the acetone can be recovered in time, the storage space of the recovery tank 8 is cleaned, and the continuity of the production is maintained, the flow meter 11 installed on one side of the discharge pump 10 synchronously records the recovery amount, the weighing meter 9 and the flow meter 11 are electrically connected, after the acetone is continuously discharged, the difference between the weighing meter 9 and the flow meter 11 will change the measurement state of the weighing meter 9 from the high limit interlocking value to the low limit interlocking value, at this time, the discharge pump 10 is closed, and the three-way regulating valve 6 is restored to the maximum opening degree, so as to realize the continuous production control of the production process of the acetone, and effectively avoid the loss of the pure water when the acetone is discharged; after the discharge amount of the flow meter 11 reaches the target value, the air inlet valve one 12 of the desolventizing kettle 1, the exhaust valve 4 and the air inlet valve two 13 of the recovery tank 8 are opened, after the nitrogen is filled into the desolventizing kettle 1 and the recovery tank 8, the residual air in the inside is discharged by the exhaust valve 4, then the exhaust valve 4, the air inlet valve one 12 and the air inlet valve two 13 are closed again, so as to maintain the cleanliness of the two tanks for use again.

[0033] The above describes one embodiment of the present application in detail, but the content described is only the preferred embodiment of the present application, and cannot be considered as limiting the implementation range of the present application. Any equivalent changes and improvements made within the scope of the present application should still belong to the patent coverage range of the present application.

Claims

1. An aqueous polyurethane acetone desolventizing recovery device, comprising a desolventizing kettle (1), one side of the desolventizing kettle (1) is provided with a recovery tank (8), characterized in that, Three-way regulating valve (6) and weighing meter (9) are installed between the desolventizing kettle (1) and the recovery tank (8) in sequence, a discharge pump (10) is installed on one side of the recovery tank (8), a flow meter (11) is installed on one side of the discharge pump (10), the weighing meter (9), the three-way regulating valve (6), the discharge pump (10) and the flow meter (11) are electrically connected, and a vacuum pump (5) is installed between the desolventizing kettle (1) and the recovery tank (8) on one side.

2. The waterborne polyurethane acetone desolventizing recovery device according to claim 1, characterized in that, An air inlet valve one (12) is installed on one side of the top end of the desolventizing kettle (1), an air inlet valve two (13) is installed on one side of the recovery tank (8), and the air inlet valve one (12) and the air inlet valve two (13) are connected with a nitrogen supply system.

3. The waterborne polyurethane acetone desolventizing recovery device according to claim 1, characterized in that, A stirring motor (2) is installed on the top end of the desolventizing kettle (1), and a temperature control system (3) is installed on one side.

4. The waterborne polyurethane acetone desolventizing recovery device according to claim 1, characterized in that, An exhaust valve (4) is installed on one side of the desolventizing kettle (1), and a vacuum regulating valve (7) is installed on the other side.

5. The waterborne polyurethane acetone desolventizing recovery device according to claim 1, characterized in that, The metering value of the weighing meter (9) is the difference between the inflow and the outflow of the flow meter (11).

6. The waterborne polyurethane acetone desolventizing recovery device according to claim 5, characterized in that, The opening of the three-way regulating valve (6) is inversely related to the metering value, the opening of the three-way regulating valve (6) is adjusted in a periodic cycle, and the three-way regulating valve (6) is kept in an open state.

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