CN207336483U - It is a kind of that there is automatic pressure-controlled VLE under reduced pressure system - Google Patents

Abstract

It is a kind of that there is automatic pressure-controlled VLE under reduced pressure system, by vapour phase sampler, liquid phase sampler, Vapor-Liquid Equilibrium Still, vacuum tank, vacuum tank, and a set of temperature control equipment and two sets of pressure control device compositions.The system of the utility model is used for the measure of VLE under reduced pressure data, has the characteristics that pressure controling precision is high, labor intensity is low, data are accurate, and is conducive to further realize that automation and digitlization improve.

Description

A decompression vapor-liquid balance system with automatic pressure control function

technical field

The invention relates to the field of thermodynamic data measurement, in particular to a decompression vapor-liquid balance system with automatic pressure control function.

Background technique

Vapor-liquid equilibrium data is the basis of industrial distillation technology, simulation calculation, computer-aided design, physical property estimation and chemical process design improvement. With the continuous development of chemical production, the existing vapor-liquid equilibrium data are far from meeting the needs. The balance data of many substances are difficult to obtain directly by theoretical calculations and must be determined by experiments. In terms of thermodynamic research, the development of new thermodynamic models and the comparison and screening of various thermodynamic models are also inseparable from a large number of accurate vapor-liquid equilibrium measured data. Due to the complexity of the vapor-liquid equilibrium system and the continuous development of the vapor-liquid equilibrium measurement technology, the vapor-liquid equilibrium measurement has also formed different types with different characteristics. According to pressure points, there are normal pressure, reduced pressure and high pressure vapor-liquid equilibrium determination.

Liquid mixtures with higher boiling points often need to be rectified under reduced pressure, so the industry often encounters the problem of rectification under reduced pressure. The vacuum vapor-liquid equilibrium data are indispensable for the simulation and design of vacuum distillation columns. At present, the more commonly used vapor-liquid balance kettle is the ROSE vapor-liquid balance kettle, which extracts the vapor phase and liquid phase samples through the syringe to analyze and measure relevant data. kPa gauge pressure), it is difficult to manually extract samples with a syringe, and air will enter the balance kettle during the sample extraction process, which will affect the accuracy. In order to solve the problem of difficult sampling in high vacuum, the inventor has designed a decompression Balance determination system (ZL201621277839.0). The inventor built the device according to the patent, and discovered during the experiment that the invention still has certain deficiencies: 1. The vacuum degree control is controlled by a manual valve, and the error is relatively large, about plus or minus 1.0 kPa, which affects the accuracy of the data, and It consumes the energy of the experimenter; 2. After the sampling process is completed, the pressure release time is long, which causes the volatilization of the light components in the sample, resulting in a low light component in the vapor phase by about 1%.

Contents of the invention

The technical problem to be solved by the present invention is to provide a decompression vapor-liquid balance system with automatic pressure control function in view of the above-mentioned technical situation.

The technical solution adopted by the present invention to solve the above technical problems is a decompression vapor-liquid balance system with automatic pressure control function, including: vapor phase sampler 1 and liquid phase sampler 9, both of which have the same structure, and the main body is suction filtration The bottle 1-1 is provided with a suction port 1-2 on the side of the suction filter bottle 1-1, the upper mouth of the suction filter bottle is plugged with a rubber stopper 1-3, and the sampling tube 1-4 passes through the middle of the rubber stopper 1-3. After that, the sampling tube 1-4 is hung with a sampling bottle 1-5 at the lower end of the suction filter bottle 1-1, and the sampling bottle 1-5 is connected with the suction filter bottle 1-1; the temperature controller 2 is provided with a temperature signal input port And control signal output end; Vapor-liquid balance kettle 5 is composed of vapor-liquid balance kettle main body 5-1, thermocouple temperature probe 5-2, electric heating rod 5-3, glass condenser tube 5-4, liquid phase sampling needle 5- 5. Vapor-phase sampling needle 5-6 is formed. The main body 5-1 of the vapor-liquid balance kettle is a ROSE vapor-liquid balance kettle, on which a liquid-phase sampling port A is plugged with a silica gel plug, and a vapor-phase sampling port B is connected Plugged with a silica gel plug, the liquid phase sampling needle 5-5 is inserted through the silica gel plug from the liquid phase sampling port A, the vapor phase sampling needle 5-6 is inserted through the silica gel plug from the vapor phase sampling port B, and the glass condenser tube 5 The lower end of -4 communicates with the interior of the vapor-liquid balance kettle, and the thermocouple temperature probe 5-2 is inserted from the upper part of the vapor-liquid balance kettle to the upper center position and is isolated from the inner cavity of the vapor-liquid balance kettle. The heating rod 5-3 is inserted from the lower part of the vapor-liquid balance kettle to the lower center position and is isolated from the inner cavity of the vapor-liquid balance kettle; the first solid state relay 6, the second solid state relay 15 and the third solid state relay 24 are the same , are provided with a control signal input terminal and a power supply output terminal; the first pressure controller 11 and the second pressure controller 22, both of which are the same, are provided with a pressure signal input terminal and a control signal output terminal; the first pressure transmitter 12 and the second pressure transmitter 21, both of which are the same, are provided with a signal output port; the pressure regulator tank 13 is provided with an air inlet, an air outlet, and a pressure transmitter interface on its upper part, and a pressure relief port on its lower part; The vacuum tank 18 is provided with a first air inlet, a second air inlet, an air outlet, and a pressure transmitter interface on its top, and a pressure relief port on its bottom; a rotary vane vacuum pump 25;

The gas extraction port 1-2 of the vapor phase sampler 1 is communicated with the first port of the first three-way through the first pipeline, and the upper end of the sampling pipe 1-4 is connected with the liquid phase sampling needle 5 through the first hose 3 -5 communication, the first flexible pipe 3 is provided with the first flexible pipe clamp 4; the vapor phase sampling needle 5-6 of the vapor-liquid balance kettle 5 passes through the second flexible pipe 7 and the sampling tube of the liquid phase sampler 9 The upper end of 1-4 is communicated, and the second hose clamp 8 is arranged on the second hose 7; the gas extraction port 1-2 of the liquid phase sampler 9 is connected with the second one of the first tee through the second pipeline. The third port of the first three-way is communicated with the first port of the second three-way through the third pipeline; the upper end of the glass condenser 5-4 of the vapor-liquid balance kettle 5 passes through The fourth pipeline communicates with the first port of the third tee; the second port of the second tee communicates with the second port of the third tee through the fifth pipeline, and on the fifth pipeline A first ball valve 10 is provided; the third port of the third tee is communicated with the air inlet of the surge tank 13 through the sixth pipeline; the pressure transmitter interface of the surge tank 13 is installed with The first pressure transmitter 12, the gas outlet communicates with the second air inlet of the vacuum tank 18 through the seventh pipeline, the first solenoid valve 16 and the first needle valve 17 are arranged on the seventh pipeline, and the pressure relief port The second ball valve 14 is installed; the third port of the second tee is communicated with the first air inlet of the vacuum tank 18 through the eighth pipeline, and the second needle valve 20 is arranged on the eighth pipeline; the described The pressure transmitter interface of the vacuum tank 18 is equipped with a second pressure transmitter 21, and the air outlet communicates with the suction port of the rotary vane vacuum pump 25 through the ninth pipeline, and a second solenoid valve is arranged on the ninth pipeline 23. A third ball valve 19 is installed at the pressure relief port;

The thermocouple temperature probe 5-2 of the vapor-liquid balance kettle 5 is connected to the temperature signal input end of the temperature controller 2 through the first wire, and the control signal output end of the temperature controller 2 is connected to the first solid state relay through the second wire 6 is connected to the control signal input end of the first solid state relay 6, and the power output end of the first solid state relay 6 is connected to the electric heating rod 5-3 of the vapor-liquid balance kettle 5 through a third wire; the signal output end of the first pressure transmitter 12 The fourth wire is connected to the pressure signal input end of the first pressure controller 11, and the control signal output end of the first pressure controller 11 is connected to the control signal input end of the second solid state relay 15 through the fifth wire, and the second solid state relay The power supply output end of 15 is connected with the first electromagnetic valve 16 through the sixth wire; the signal output end of the second pressure transmitter 21 is connected with the pressure signal input end of the second pressure controller 22 through the seventh wire. The control signal output end of the second pressure controller 22 is connected with the control signal input end of the third solid state relay 24 through the eighth wire, and the power output end of the third solid state relay 24 is connected with the second electromagnetic valve 23 through the ninth wire, and is connected with the second solenoid valve 23 through the eighth wire. Ten wires are connected with the rotary vane vacuum pump 25.

As an improvement, the first solenoid valve 16 and the second solenoid valve 23 are both normally closed solenoid valves.

Compared with the prior art, the present invention has the following advantages: 1. The pressure of the vacuum tank and the surge tank is controlled respectively by two sets of automatic pressure control systems. Compared with manual control, the control accuracy is greatly improved, and the pressure of the surge tank can be controlled It is about positive and negative 0.1 kPa, and greatly reduces the work intensity of the experimenter; 2. Through the temperature control system, the heating process of the vapor-liquid balance kettle is automatically adjusted, which also reduces the work intensity of the experimenter; 3. Through the new pipeline The design realizes the rapid pressure relief process, avoids the long-term exposure of the sample to low pressure, reduces the volatilization of light components in the sample, and improves the measurement accuracy.

Description of drawings

Fig. 1 is a schematic flow chart of a decompression vapor-liquid balance system with automatic pressure control function of the present invention.

Fig. 2 is a schematic diagram of a vapor phase sampler and a liquid phase sampler of a decompression vapor-liquid balance system with automatic pressure control function of the present invention.

Fig. 3 is a schematic diagram of a vapor-liquid balance tank of a decompression vapor-liquid balance system with an automatic pressure control function according to the present invention.

Among them: 1 is the vapor phase sampler, 2 is the temperature controller, 3 is the first hose, 4 is the first hose card, 5 is the vapor-liquid balance tank, 6 is the first solid state relay, 7 is the second hose , 8 is the second hose card, 9 is the liquid phase sampler, 10 is the first ball valve, 11 is the first pressure controller, 12 is the first pressure transmitter, 13 is the surge tank, 14 is the second ball valve , 15 is the second solid state relay, 16 is the first solenoid valve, 17 is the first needle valve, 18 is the vacuum tank, 19 is the third ball valve, 20 is the second needle valve, 21 is the second pressure transmitter , 22 is the second pressure controller, 23 is the second solenoid valve, 24 is the third solid state relay, 25 is the rotary vane vacuum pump, 1-1 is the vacuum bottle, 1-2 is the air outlet, 1-3 is the rubber plug , 1-4 is the sampling tube, 1-5 is the sampling bottle, 5-1 is the main body of the vapor-liquid balance kettle, 5-2 is the thermocouple temperature probe, 5-3 is the electric heating rod, 5-4 is the glass condenser tube, 5-5 is a liquid phase sampling needle, 5-6 is a vapor phase sampling needle, A is a liquid phase sampling port, and B is a vapor phase sampling port.

Detailed ways

Below in conjunction with accompanying drawing 1, accompanying drawing 2, accompanying drawing 3, the present invention will be described in further detail through the embodiment.

The vapor phase sampler 1 and the liquid phase sampler 9 have the same structure. The main body is a suction filter bottle 1-1. An air suction port 1-2 is arranged on the side of the suction filter bottle 1-1. The upper plug of the suction filter bottle There is a rubber stopper 1-3, and the sampling tube 1-4 passes through the middle of the rubber stopper 1-3. The sampling tube 1-4 is hung with a sampling bottle 1-5 at the lower end of the suction filter bottle 1-1, and the sampling bottle 1- 5 is connected with the suction filter bottle 1-1; the temperature controller 2 is provided with a temperature signal input terminal and a control signal output terminal; the vapor-liquid balance kettle 5 is composed of a vapor-liquid balance kettle main body 5-1 and a thermocouple temperature probe 5-2 , an electric heating rod 5-3, a glass condenser tube 5-4, a liquid phase sampling needle 5-5, and a vapor phase sampling needle 5-6, and the main body 5-1 of the vapor-liquid balance kettle is a ROSE vapor-liquid balance kettle, It is provided with a liquid phase sampling port A and plugged with a silica gel plug, and a vapor phase sampling port B is plugged with a silica gel plug. The liquid phase sampling needle 5-5 is inserted from the liquid phase sampling port A through the silica gel plug, and the vapor phase sampling needle 5 -6 is inserted through the silica gel plug from the vapor phase sampling port B, the lower end of the glass condenser tube 5-4 communicates with the inside of the vapor-liquid balance kettle, and the thermocouple temperature probe 5-2 is connected from the upper part of the vapor-liquid balance kettle Inserted into the upper center position and isolated from the inner cavity of the vapor-liquid balance kettle, the electric heating rod 5-3 is inserted from the lower part of the vapor-liquid balance kettle to the lower center position and isolated from the inner cavity of the vapor-liquid balance kettle; The first solid state relay 6, the second solid state relay 15 and the third solid state relay 24, the three are the same, and are provided with control signal input terminals and power output terminals; the first pressure controller 11 and the second pressure controller 22, both The same, both are provided with a pressure signal input terminal and a control signal output terminal; the first pressure transmitter 12 and the second pressure transmitter 21 are the same, both are provided with a signal output terminal; There is an air inlet, an air outlet, and a pressure transmitter interface, and the lower part is provided with a pressure relief port; the upper part of the vacuum tank 18 is provided with a first air inlet, a second air inlet, an air outlet, and a pressure transmitter interface, The lower part is provided with a pressure relief port; the rotary vane vacuum pump 25;

The gas extraction port 1-2 of the vapor phase sampler 1 is communicated with the first port of the first three-way through the first pipeline, and the upper end of the sampling pipe 1-4 is connected with the liquid phase sampling needle 5 through the first hose 3 -5 communication, the first flexible pipe 3 is provided with the first flexible pipe clamp 4; the vapor phase sampling needle 5-6 of the vapor-liquid balance kettle 5 passes through the second flexible pipe 7 and the sampling tube of the liquid phase sampler 9 The upper end of 1-4 is communicated, and the second hose clamp 8 is arranged on the second hose 7; the gas extraction port 1-2 of the liquid phase sampler 9 is connected with the second one of the first tee through the second pipeline. The third port of the first three-way is communicated with the first port of the second three-way through the third pipeline; the upper end of the glass condenser 5-4 of the vapor-liquid balance kettle 5 passes through The fourth pipeline communicates with the first port of the third tee; the second port of the second tee communicates with the second port of the third tee through the fifth pipeline, and on the fifth pipeline A first ball valve 10 is provided; the third port of the third tee is communicated with the air inlet of the surge tank 13 through the sixth pipeline; the pressure transmitter interface of the surge tank 13 is installed with The first pressure transmitter 12, the gas outlet communicates with the second air inlet of the vacuum tank 18 through the seventh pipeline, the first solenoid valve 16 and the first needle valve 17 are arranged on the seventh pipeline, and the pressure relief port The second ball valve 14 is installed; the third port of the second tee is communicated with the first air inlet of the vacuum tank 18 through the eighth pipeline, and the second needle valve 20 is arranged on the eighth pipeline; the described The pressure transmitter interface of the vacuum tank 18 is equipped with a second pressure transmitter 21, and the air outlet communicates with the suction port of the rotary vane vacuum pump 25 through the ninth pipeline, and a second solenoid valve is arranged on the ninth pipeline 23. A third ball valve 19 is installed at the pressure relief port;

The thermocouple temperature probe 5-2 of the vapor-liquid balance kettle 5 is connected to the temperature signal input end of the temperature controller 2 through the first wire, and the control signal output end of the temperature controller 2 is connected to the first solid state relay through the second wire 6 is connected to the control signal input end of the first solid state relay 6, and the power output end of the first solid state relay 6 is connected to the electric heating rod 5-3 of the vapor-liquid balance kettle 5 through a third wire; the signal output end of the first pressure transmitter 12 The fourth wire is connected to the pressure signal input end of the first pressure controller 11, and the control signal output end of the first pressure controller 11 is connected to the control signal input end of the second solid state relay 15 through the fifth wire, and the second solid state relay The power supply output end of 15 is connected with the first electromagnetic valve 16 through the sixth wire; the signal output end of the second pressure transmitter 21 is connected with the pressure signal input end of the second pressure controller 22 through the seventh wire. The control signal output end of the second pressure controller 22 is connected with the control signal input end of the third solid state relay 24 through the eighth wire, and the power output end of the third solid state relay 24 is connected with the second electromagnetic valve 23 through the ninth wire, and is connected with the second solenoid valve 23 through the eighth wire. Ten wires are connected with the rotary vane vacuum pump 25.

The operating process of a decompression vapor-liquid balance system with automatic pressure control function of the present invention is as follows:

(1) Add the liquid mixture to be tested into the vapor-liquid balance kettle 5, ensure that the first ball valve 10 and the first needle valve 17 are opened, and ensure that the second ball valve 14, the third ball valve 19 and the second needle valve 20 are closed and opened Power supply, set the pressure of the first pressure controller 11 to -50 kPa (gauge pressure), set the pressure of the second pressure controller 22 to -70 kPa (gauge pressure) (usually the pressure of the vacuum tank is 20 kPa lower than that of the surge tank ), turn on the rotary vane vacuum pump 25, and the pressure control system can control the pressure of the vacuum tank 18 and the pressure regulator tank 13 at the above-mentioned set pressure through the action of the electromagnetic relay, and the error is about plus or minus 0.1 kPa. At this time, the vapor-liquid balance The set temperature and pressure in the kettle 5 is consistent with the pressure of the surge tank 13 at -50 kPa, and the temperature controller 2 is set. The temperature controller can realize program temperature rise. When the temperature value is stable, the heating power is automatically stabilized and can be set. Keep the heating time constant for 0.5 hours until the gas-liquid two phases are completely balanced.

(2) Close the first ball valve 10, open the second needle valve 20 for about 10 seconds and then close it. At this time, the pressure in the vapor phase sampler 1 and liquid phase sampler 9 is consistent with the pressure of the vacuum tank 18 at -70 kPa , the pressure in the sampler is 20 kPa lower than the pressure in the vapor-liquid balance tank 5, and the first hose clamp 4 and the second hose clamp 8 are respectively opened for about 5 seconds to suck the sample into the liquid phase sampler 1 and the vapor phase The sampling bottles 1-5 in the sampler 9 quickly open the first ball valve 10. At this time, the pressure in the sampler 1 and 9 is instantly consistent with the vapor-liquid balance kettle, preventing the volatilization of the sample. Turn off the power and open the second ball valve 14 And the third ball valve 19, the device is completely decompressed, and the sampling bottle 1-5 is taken out by pulling out the rubber stopper 1-3 of the liquid phase sampler 1 and the vapor phase sampler 9, and the sample is analyzed to obtain the vapor-liquid balance data .

Claims (2)

1. a kind of have the function of automatic pressure-controlled VLE under reduced pressure system, it is characterised in that：The system includes：Vapour phase takes Sample device and liquid phase sampler, both structures are identical, and main body is bottle,suction, and the side of bottle,suction is provided with bleeding point, bottle,suction It is suitable for reading be plugged with rubber stopper, probe tube is passed through from the centre of rubber stopper, and lower end of the probe tube in bottle,suction hangs with sampling bottle, takes Sample bottle is connected with bottle,suction；Temperature controller, is provided with temperature signal input and control signal output；Vapor-Liquid Equilibrium Still, By Vapor-Liquid Equilibrium Still main body, thermocouple temperature probe, electrically heated rod, glass cold traps, liquid phase sampling probe, vapour phase sampling probe structure Into the Vapor-Liquid Equilibrium Still main body is ROSE Vapor-Liquid Equilibrium Stills, is provided with liquid phase sample tap and is plugged with silica gel plug, vapour phase Sample tap is simultaneously plugged with silica gel plug, and liquid phase sampling probe is inserted into through silica gel plug from liquid phase sample tap, and vapour phase sampling probe passes through silica gel plug It is inserted into from vapour phase sample tap, the lower end of the glass cold traps inside Vapor-Liquid Equilibrium Still with connecting, the electric thermo-couple temperature Probe is inserted into central upper portion position from the top of Vapor-Liquid Equilibrium Still and isolates with the internal cavity of Vapor-Liquid Equilibrium Still, the electricity Heating rod is inserted into lower central position from the lower part of Vapor-Liquid Equilibrium Still and isolates with the internal cavity of Vapor-Liquid Equilibrium Still；First is solid State relay, the second solid-state relay and the 3rd solid-state relay, three is identical, is equipped with control signal input and power supply is defeated Outlet；First pressure controller and second pressure controller, both are identical, are both provided with pressure signal input end and control signal Output terminal；First pressure transmitter and second pressure transmitter, both are identical, are equipped with signal output part；Vacuum tank, its upper part Air inlet, gas outlet, pressure transmitter interface are provided with, lower part is provided with pressure relief opening；Vacuum tank, its upper part be provided with first into Gas port, the second air inlet, gas outlet, pressure transmitter interface, its underpart is provided with pressure relief opening；Rotary-vane vaccum pump；

The bleeding point of the vapour phase sampler is connected by the first pipeline with first mouth of the first threeway, the upper end of probe tube Connected by the first hose with liquid phase sampling probe, the first hose clamp is provided with the first hose；The vapour of the Vapor-Liquid Equilibrium Still Phase sampling probe is connected by the second hose with the upper end of the probe tube of liquid phase sampler, and the second hose is provided with the second hose Card；The bleeding point of the liquid phase sampler is connected by the second pipeline with second mouth of the first threeway；Described the one or three The 3rd logical mouth is connected by the 3rd pipeline with first mouth of the second threeway；The glass cold traps of the Vapor-Liquid Equilibrium Still Upper end connected by the 4th pipeline with first mouth of the 3rd threeway；Second mouth of second threeway passes through the 5th pipe Second mouth connection of tri- threeways of Lu Yu, the first ball valve is provided with the 5th pipeline；The 3rd of 3rd threeway Mouth is connected by the 6th pipeline with the air inlet of vacuum tank；The pressure transmitter interface of the vacuum tank is installed with first pressure Transmitter, gas outlet are connected by the 7th pipeline with the second air inlet of vacuum tank, and the first electromagnetism is provided with the 7th pipeline Valve and the first needle valve, pressure relief opening are mounted with the second ball valve；3rd mouth of the second threeway passes through the 8th pipeline and vacuum tank First air inlet connects, and the second needle valve is provided with the 8th pipeline；The pressure transmitter interface installation of the vacuum tank There is second pressure transmitter, gas outlet is connected by the 9th pipeline with the air entry of rotary-vane vaccum pump, and on the 9th pipeline Second solenoid valve is provided with, pressure relief opening is provided with the 3rd ball valve；

The thermocouple temperature probe of the Vapor-Liquid Equilibrium Still passes through the first conducting wire and the temperature signal input of temperature controller Connection, the control signal output of temperature controller are connected by the control signal input of the second conducting wire and the first solid-state relay Connect, the power output end of the first solid-state relay is connected by the electrically heated rod of privates and Vapor-Liquid Equilibrium Still；Described The signal output part of one pressure transmitter is connected by privates with the pressure signal input end of first pressure controller, and first The control signal output of pressure controller is connected by the 5th conducting wire with the control signal input of the second solid-state relay, the The power output end of two solid-state relays is connected by the 6th conducting wire with the first solenoid valve；The letter of the second pressure transmitter Number output terminal is connected by the 7th conducting wire with the pressure signal input end of second pressure controller, the control of second pressure controller Signal output part is connected by the 8th conducting wire with the control signal input of the 3rd solid-state relay, the electricity of the 3rd solid-state relay Source output terminal is connected by the 9th conducting wire with second solenoid valve, is connected by the tenth conducting wire with rotary-vane vaccum pump.

2. system according to claim 1, it is characterised in that：First solenoid valve and second solenoid valve are normally closed Formula solenoid valve.