CN213854559U - Device for replacing vinyl chloride polymerization kettle - Google Patents

Abstract

The utility model provides a device for vinyl chloride polymerization kettle replacement, which comprises a polymerization kettle system and a water pumping pipeline, wherein the first end of the water pumping pipeline is communicated with a discharge pump inlet pipe between a discharge pump and a second discharge ball valve, the second end of the water pumping pipeline is communicated with a mother liquor water regulating tank, and the water pumping pipeline is also provided with a water pumping valve; the utility model discloses a device for chloroethylene polymerization kettle replacement, the mode of utilizing mother liquor water to replace the mode of directly beating the monomer replacement after the vacuum pumping, guarantee that the air in the polymerization kettle 1 is replaced totally, the potential safety hazard when directly letting in chloroethylene under the condition that there is air in the kettle is eliminated; meanwhile, only a water fetching pipeline and a water fetching valve 17 are additionally arranged on a discharging unit of the existing polymerization kettle system, so that the system is convenient and practical and is convenient to popularize.

Description

Device for replacing vinyl chloride polymerization kettle

Technical Field

The utility model relates to a polyvinyl chloride industry field especially relates to a device for displacement of chloroethylene polymeric kettle.

Background

The polymerizer is a key device in industrial production of polyvinyl chloride, and has direct influence on the quality and yield of resin products, production cost, labor conditions, safety production and the like, so that in the polyvinyl chloride industry of many countries, sufficient attention is paid to the design, manufacture and use of the polymerizer, and research and test are carried out for many years.

The structure of the existing polymerizer system is:

as shown in fig. 1: comprises a polymerization kettle 1, a vacuumizing unit, a vinyl chloride recovery unit, a vinyl chloride emptying unit and a discharging unit; a vinyl chloride feeding hole and a vinyl chloride recovery hole are formed in a polymerization kettle 1, the vinyl chloride feeding hole is used for adding vinyl chloride to the polymerization kettle 1, a gas phase main pipe is connected to the vinyl chloride recovery hole, a first butterfly valve 6 is arranged on the gas phase main pipe, the gas phase main pipe behind the first butterfly valve 6 is divided into three gas phase branch pipes, namely a vacuumizing branch pipe of a vacuumizing unit, a recovery branch pipe of the vinyl chloride recovery unit and an emptying branch pipe of a vinyl chloride emptying unit, the vacuumizing unit further comprises a vacuumizing valve 7 and a vacuum pump 2 which are arranged on the vacuumizing branch pipe, the vinyl chloride emptying unit further comprises an emptying valve 8 which is arranged on the emptying branch pipe, the vinyl chloride recovery unit further comprises a first recovery valve 9 and a second recovery valve 10 which are sequentially arranged on the recovery branch pipe, and the tail end of the recovery branch pipe is connected with a catcher 4; the bottom of the polymerizer 1 is provided with a discharge hole, the discharge unit comprises a discharge main pipe, a mother liquid water inlet pipe, a discharge pump inlet pipe and a discharge pump 5, one end of the discharge main pipe is communicated with the discharge hole, the discharge main pipe is provided with a plunger valve 12, the other end of the discharge main pipe is divided into the mother liquid water inlet pipe and the discharge pump inlet pipe, and the mother liquid water inlet pipe is communicated with a mother liquid water pump at the outlet of a mother liquid water tank through a feed ball valve 13 and is used for providing mother liquid water for the polymerizer 1; an inlet pipe of the discharge pump is communicated with the discharge chute 3 through a first discharge ball valve 14, the discharge pump 5 and a second discharge ball valve 15 in sequence; the top of the discharge chute 3 is also connected to a recovery branch pipe between the first recovery valve 9 and the second recovery valve 10 through a discharge chute recovery pipe, and a gas phase recovery valve 11 is arranged on the discharge chute recovery pipe; a waste water branch pipe is connected to a discharging pump inlet pipe between the discharging pump 5 and the second discharging ball valve 15, a waste water valve 16 is arranged on the waste water branch pipe, and the waste water branch pipe is connected to a waste water tank.

Since the 70m vinyl chloride polymerizing kettle 1 needs to be completely replaced by the residual air in the polymerizing kettle 1 through the vacuumizing unit after uncovering and overhauling and before putting into operation again, the pressure control of the normal reaction of the polymerizing kettle 1 is prevented from being influenced by the inert gas contained in the polymerizing kettle 1; the existing replacement method is that a water-ring vacuum pump 2 is used for pumping the pressure in a polymerization kettle 1 to-50 kPa, then 2-3 tons of liquid-phase chloroethylene is pumped into the polymerization kettle 1 through a chloroethylene feeding hole, high-pressure steam is introduced into the bottom of the polymerization kettle 1 for heating, and then a water-ring compressor is used for recovering the gasified chloroethylene in the polymerization kettle 1 to a compression recovery system for condensation; continuously introducing high-pressure steam into the polymerization kettle 1, and stopping after the liquid-phase chloroethylene in the polymerization kettle 1 is completely recovered, so that the replacement work of the polymerization kettle 1 is completed.

However, in the above-mentioned method of replacing with high-pressure steam, there may be a case where the air in the polymerizer 1 is not completely pumped by the vacuum pump 2, and in this case, when vinyl chloride is introduced into the polymerizer 1, the vinyl chloride directly contacts with the air, and the lower explosion limit of vinyl chloride gas is 3.6%, which may cause a safety hazard.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a device for chloroethylene polymeric kettle replaces the mode that current evacuation back directly beats liquid phase chloroethylene replacement with the mode that utilizes mother liquor water replacement, guarantees that the air replacement in the polymeric kettle is clean, has eliminated the potential safety hazard when directly letting in chloroethylene under the condition of air in the cauldron.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

an apparatus for vinyl chloride polymerizer replacement, comprising a polymerizer system; still including the pipeline of fetching water, the first end of pipeline of fetching water communicates with the ejection of compact pump import pipe between ejection of compact pump and the second ejection of compact ball valve, and the second end of pipeline of fetching water communicates with mother liquor water regulation pond, still is provided with the valve of fetching water on the pipeline of fetching water.

The polymerization kettle system comprises a polymerization kettle, a vinyl chloride recovery unit, a vinyl chloride emptying unit and a discharging unit.

The water valve adopts a ball valve.

The utility model has the advantages that:

the utility model discloses a device for chloroethylene polymerization kettle replacement, the mode of utilizing mother liquor water to replace the mode of directly beating the monomer replacement after the vacuum pumping, guarantee that the air in the polymerization kettle 1 is replaced totally, the potential safety hazard when directly letting in chloroethylene under the condition that there is air in the kettle is eliminated; meanwhile, only a water fetching pipeline and a water fetching valve 17 are additionally arranged on a discharging unit of the existing polymerization kettle system, so that the system is convenient and practical and is convenient to popularize.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the technical solutions in the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic view of a prior art polymerizer system described in the background section;

fig. 2 is a schematic structural diagram of the present invention.

Detailed Description

The technical solution of the present invention will be described clearly and completely with reference to the accompanying drawings, and obviously, the described embodiments are some, but not all embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

As shown in fig. 2: the utility model relates to a device for replacing a vinyl chloride polymerization kettle, which comprises a polymerization kettle system and a water pumping pipeline; the polymerization kettle system adopts the prior polymerization kettle system in the background technology; the first end of the water-fetching pipeline is communicated with the discharging pump inlet pipe between the discharging pump 5 and the second discharging ball valve 15, the second end of the water-fetching pipeline is communicated with the mother liquor water adjusting tank 18, and the water-fetching pipeline is further provided with a water-fetching valve 17.

Preferably: the polymerization kettle system comprises a polymerization kettle 1, a vinyl chloride recovery unit, a vinyl chloride emptying unit and a discharging unit; compare with current polymeric kettle system promptly, a polymeric kettle 1 for among the device of chloroethylene polymeric kettle replacement, need not use the evacuation unit can.

Preferably: the water valve 17 adopts a ball valve.

A theory of operation that is used for vinyl chloride polymeric kettle to replace device be:

opening a plunger valve 12 on a discharge main pipe and a feed ball valve 13 on a mother liquid water inlet pipe, and injecting mother liquid water into the polymerization kettle 1 by a mother liquid water pump; simultaneously opening a first butterfly valve 6 on the gas phase main pipe and an emptying valve 8 on the emptying branch pipe; if mother liquor water flows out of the emptying branch pipe, a feed ball valve 13 on the mother liquor water inlet pipe and an emptying valve 8 on the emptying branch pipe are closed; at the moment, the polymerization kettle 1 is completely filled with the mother liquid water, the air in the polymerization kettle 1 is completely discharged along the emptying branch pipe, and the mother liquid water in the polymerization kettle 1 is only emptied before the polymerization kettle 1 is produced again; specifically, the method comprises the following steps: opening a first discharge valve 14 on an inlet pipe of a discharge pump, the discharge pump 5 and a water pumping valve 17 on a water pumping pipeline, simultaneously opening a first recovery valve 9 on a recovery branch pipe and a gas phase recovery valve 11 on a discharge tank recovery pipe, opening a stirring motor of the polymerizer 1, and enabling positive pressure in a discharge tank 3 to enter the polymerizer 1 through the discharge tank recovery pipe and the recovery branch pipe in series; further, mother liquor in the polymerization kettle 1 enters a mother liquor adjusting tank 18 through a water fetching pipeline under the driving of a discharge pump 5; when the stirring current of the stirring motor is reduced to between 80 and 100A, closing the water pumping valve 17, and simultaneously opening the second discharge valve to enable the mother liquor in the polymerization kettle 1 to enter the discharge tank 3; when the mother liquid water in the polymerization kettle 1 is more, the mother liquid water can be directly discharged to the mother liquid water regulating tank 18, and when the mother liquid water is less, in order to prevent the mother liquid water in the polymerization kettle 1 from being exhausted, the condition that the water pumping valve 17 is not closed in time (prevent the vinyl chloride in the kettle from entering the mother liquid water regulating tank 18 to cause vinyl chloride leakage to be dangerous) occurs, therefore, when the stirring current of the stirring motor falls to between 80 and 100A, the water pumping valve 17 is closed, and simultaneously, the second discharging valve is opened to enable the mother liquid water in the polymerization kettle 1 to enter the discharging tank 3; because the working current of the stirring motor is between 30A and 180A, 30A is the working current of the stirring motor in idle running, and 180A is the working current of the polymerization kettle 1 in full, through a plurality of tests, the utility model discloses a when selecting the stirring current to drop to 83A, close the water valve 17; further, the water pumping valve 17 is closed, after the second discharge valve is opened, if the liquid level in the discharge chute 3 is higher than the highest allowable liquid level, the second discharge valve is closed, and the waste water valve 16 on the waste water branch pipe is opened, so that the mother liquid water in the polymerizer 1 flows out from the waste water branch pipe, and the situation that the liquid level in the discharge chute 3 is too high is prevented; and when the stirring current of the stirring motor is reduced to the current value when the stirring motor idles, the discharge pump 5 and the stirring motor are closed, and the replacement process is completed.

The utility model discloses a device for chloroethylene polymerization kettle replacement, the mode of utilizing mother liquor water to replace the mode of directly beating the monomer replacement after the vacuum pumping, guarantee that the air in the polymerization kettle 1 is replaced totally, the potential safety hazard when directly letting in chloroethylene under the condition that there is air in the kettle is eliminated; meanwhile, only a water fetching pipeline and a water fetching valve 17 are additionally arranged on a discharging unit of the existing polymerization kettle system, so that the system is convenient and practical and is convenient to popularize.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention.

Claims (3)

1. An apparatus for vinyl chloride polymerizer replacement, comprising a polymerizer system; the method is characterized in that: still including the pipeline of fetching water, the first end of pipeline of fetching water communicates with the ejection of compact pump import pipe between ejection of compact pump and the second ejection of compact ball valve, and the second end of pipeline of fetching water communicates with mother liquor water regulation pond, still is provided with the valve of fetching water on the pipeline of fetching water.

2. An apparatus for vinyl chloride polymerization kettle replacement according to claim 1, wherein: the polymerization kettle system comprises a polymerization kettle, a vinyl chloride recovery unit, a vinyl chloride emptying unit and a discharging unit.

3. An apparatus for vinyl chloride polymerization kettle replacement according to claim 1, wherein: the water valve adopts a ball valve.

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