Improved heating steam pressure stabilizing system for DMAC (dimethylacetamide) refining tower

Abstract

The utility model provides an improved DMAC (dimethylacetamide) refining tower heating steam pressure stabilizing system which is used for being connected with a boiler room and comprises an automatic regulating valve, a pressure transmitter, a pressure buffer tank, an electronic pressure gauge, a steam distributing pocket, a drain valve, a refining tower, a reboiler, a cooling unit, a reflux tank, a reflux pump, a vacuum pump, a first valve and a second valve, the refining tower can stably recycle qualified DMAC, and it is guaranteed that the electronic pressure gauge is not prone to damage.

Description

TECHNICAL FIELD

[0001] The utility model relates to an improved DMAC refining tower heating steam pressure stabilizing system. BACKGROUND

[0002] The liquid DMAC solvent used in the production of spandex workshop needs to be recycled through a refining tower. In the process of recycling DMAC, high-temperature steam is used to heat DMAC. Through heating, the liquid DMAC containing impurities becomes gaseous DMAC, which is then condensed into liquid by a cooling system, so as to achieve the purpose of separating and recycling qualified DMAC. In the recycling process, the heating temperature at the bottom of the refining tower is an important parameter of the entire recycling process, and the bottom temperature is controlled by steam heating. Therefore, stable heating steam pressure determines the success or failure of the entire refining tower recycling process.

[0003] Currently, the DMAC heating steam pressure is jointly adjusted and controlled by a remote electronic pressure gauge and an automatic regulating valve. However, when the electronic pressure gauge is directly connected to the steam, the pressure gauge shows large pressure fluctuations, and the high-temperature steam causes great corrosion to the electronic pressure gauge, which is easily damaged after long-term contact. UTILITY MODEL CONTENTS

[0004] The technical problem to be solved by the utility model is to provide an improved DMAC refining tower heating steam pressure stabilizing system, so that the refining tower can stably recycle qualified DMAC and ensure that the electronic pressure gauge is not easily damaged.

[0005] The utility model is implemented as follows: an improved DMAC refining tower heating steam pressure stabilizing system is used to connect a boiler room, which comprises an automatic regulating valve, a pressure transmitter, a pressure buffer tank, an electronic pressure gauge, a steam distribution header, a drain valve, a refining tower, a reboiler, a cooling unit, a reflux tank, a reflux pump, a vacuum pump, a first valve, and a second valve.

[0006] The boiler room is connected to the steam distribution header through the automatic regulating valve. The pressure buffer tank is arranged between the automatic regulating valve and the steam distribution header. The pressure buffer tank is connected to the electronic pressure gauge. The steam distribution header is connected to the refining tower. The top of the refining tower is connected to the cooling unit. The cooling unit is connected to the top of the reflux tank. The bottom of the reflux tank is connected to the reflux pump. The reflux pump is connected to the top of the reflux tank through the first valve. The reflux pump is connected to the upper part of the refining tower through the second valve. The cooling unit is connected to the vacuum pump. The lower part of the refining tower is connected to the upper part of the reboiler. The top of the reboiler is connected to the middle part of the refining tower. The bottom of the reboiler is connected to the bottom of the refining tower. The reboiler is provided with a steam condensate water outlet.

[0007] The pressure transmitter is electrically connected with the electronic pressure gauge and the automatic regulating valve.

[0008] Further, a third valve and a fourth valve are arranged on both sides of the automatic regulating valve.

[0009] Further, a fifth valve and a sixth valve are arranged on both sides of the steam trap.

[0010] Further, a seventh valve is arranged in parallel with the steam trap.

[0011] Further, an eighth valve is arranged between the cooling unit and the vacuum pump.

[0012] Further, the cooling unit comprises a first cooler and a second cooler, the top of the refining tower is connected to the air inlet of the first cooler, the air outlet of the first cooler is connected to the air inlet of the second cooler, and the air outlet of the second cooler is connected to the vacuum pump; the condensate outlet of the first cooler and the condensate outlet of the second cooler are both connected to the top of the reflux tank.

[0013] The improved DMAC refining tower heating steam pressure stabilizing system has the advantages that the electronic pressure gauge ensures that low-pressure steam is stably introduced into the refining tower, so that the system stably recovers DMAC, and the pressure obtained by the electronic pressure gauge is accurate and reliable, and the electronic pressure gauge is not easily damaged. BRIEF DESCRIPTION OF DRAWINGS

[0014] The improved DMAC refining tower heating steam pressure stabilizing system will be further described below with reference to the embodiments and the accompanying drawings.

[0015] Figure 1 is a schematic view of the improved DMAC refining tower heating steam pressure stabilizing system. DETAILED DESCRIPTION

[0016] Please refer to Figure 1 The improved DMAC refining tower heating steam pressure stabilizing system is used for connecting a boiler room a, and comprises an automatic regulating valve 101, a pressure transmitter 102, a pressure buffer tank 103, an electronic pressure gauge 104, a steam drum 105, a steam trap 106, a refining tower 107, a reboiler 108, a cooling unit 109, a reflux tank 110, a reflux pump 111, a vacuum pump 112, a first valve 113 and a second valve 114.

[0017] The boiler room a is connected to the steam drum 105 through an automatic regulating valve 101, the pressure buffer tank 103 is arranged between the automatic regulating valve 101 and the steam drum 105, the pressure buffer tank 103 is connected to the electronic pressure gauge 104, the electronic pressure gauge 104 is not in direct contact with the steam through the pressure buffer tank 103, but can accurately detect the pressure value, greatly increasing the service life of the electronic pressure gauge 104, and the accuracy of detection makes it possible to accurately control the automatic regulating valve 101, so that the steam stably enters the refining tower 107; the steam drum 105 is connected to the refining tower 107, the top of the refining tower 107 is connected to the cooling unit 109, the top of the cooling unit 109 is connected to the reflux tank 110, the bottom of the reflux tank 110 is connected to the reflux pump 111, the reflux pump 111 is connected to the top of the reflux tank 110 through the first valve 113; the reflux pump 111 is connected to the upper part of the refining tower 107 through the second valve 114; the cooling unit 109 is connected to the vacuum pump 112; the lower part of the refining tower 107 is connected to the upper part of the reboiler 108, the top of the reboiler 108 is connected to the middle part of the refining tower 107, the bottom of the reboiler 108 is connected to the bottom of the refining tower 107, and the reboiler 108 is provided with a steam condensate outlet 1081;

[0018] The pressure transmitter 102 is electrically connected to the electronic pressure gauge 104 and the automatic regulating valve 101, wherein the pressure transmitter 102 converts the pressure value of the electronic pressure gauge 104 into an electric signal and sends it to the automatic regulating valve 101 to control the automatic regulating valve 101 to adjust; low-pressure steam enters the refining tower 107 from the steam drum 105, and in the process of recycling DMAC, the refining tower 107 needs to heat DMAC with high-temperature steam, through heating, impurity-containing liquid DMAC becomes gaseous DMAC, and then the gaseous DMAC is condensed into liquid by the cooling unit 109, so as to achieve the purpose of separating and recycling qualified DMAC; then the DMAC is refluxed into the refining tower 107 by the reflux pump 111; the material liquid level of the reboiler 108 and the liquid level of the refining tower 107 are at the same height, liquid phase is provided from the bottom of the refining tower 107 into the reboiler 108, and usually 25-30% of the liquid phase in the reboiler is vaporized, and the two-phase flow vaporized is sent back to the refining tower 107.

[0019] In this embodiment, preferably, a third valve 115 and a fourth valve 116 are further included, and the third valve 115 and the fourth valve 116 are arranged on both sides of the automatic regulating valve 101; the third valve 115 and the fourth valve 116 are normally open switches, which are closed when the automatic regulating valve 101 needs to be replaced or repaired.

[0020] In this embodiment, preferably, a fifth valve 117 and a sixth valve 118 are arranged on both sides of the drain valve 106, the fifth valve 117 and the sixth valve 118 are normally open switches, and the fifth valve 117 and the sixth valve 118 are closed when the drain valve 106 needs to be replaced or repaired.

[0021] In this embodiment, preferably, a seventh valve 119 is arranged in parallel with the drain valve 106, and the seventh valve 119 is opened to drain water when the drain valve 106 fails, so as to prevent the system from failing.

[0022] In this embodiment, preferably, an eighth valve 120 is arranged between the cooling unit 109 and the vacuum pump 112, and the eighth valve 120 is closed when the internal vacuum degree is sufficient.

[0023] In this embodiment, preferably, the cooling unit 109 comprises a first cooler 1091 and a second cooler 1092, the top of the refining tower 107 is connected to an air inlet of the first cooler 1091, an air outlet of the first cooler 1091 is connected to an air inlet of the second cooler 1092, and an air outlet of the second cooler 1092 is connected to the vacuum pump 112; a condensate outlet of the first cooler 1091 and a condensate outlet of the second cooler 1092 are both connected to the top of the reflux tank 110; a closed cooler usually needs to be vacuumized. When the closed cooler is running, a closed space is formed in the closed cooler, and the cooling medium circulates in the closed space. If there is air or other non-condensable gas in the closed cooler, the heat exchange efficiency will be affected, and even the performance of the closed cooler will be reduced. Therefore, before using the closed cooler, the closed cooler needs to be vacuumized to remove the non-condensable gas in the closed cooler, so as to improve the cooling efficiency and prolong the service life.

[0024] In the description of the utility model, it should be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the utility model and simplify the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore, it cannot be understood as a limitation on the utility model. In the description of the utility model, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0025] Although the specific embodiments of the present application are described above, those skilled in the art should understand that the specific embodiments described by us are only illustrative, not for limiting the scope of the present application, and equivalent modifications and changes made by those skilled in the art in accordance with the spirit of the present application should be covered within the scope of the claims of the present application.

Claims

1. An improved DMAC refining column heating steam pressure stabilizing system for connecting to a boiler room, characterized in that: The utility model relates to a boiler room automatic control system, including: Automatic regulating valve, pressure transmitter, pressure buffer tank, electronic pressure gauge, steam drum, trap, refining tower, reboiler, cooling unit, reflux tank, reflux pump, vacuum pump, first valve and second valve; The boiler room is connected to the steam drum through the automatic regulating valve, the pressure buffer tank is arranged between the automatic regulating valve and the steam drum, the pressure buffer tank is connected to the electronic pressure gauge, the steam drum is connected to the refining tower, the top of the refining tower is connected to the cooling unit, the top of the cooling unit is connected to the reflux tank, the bottom of the reflux tank is connected to the reflux pump, the reflux pump is connected to the top of the reflux tank through the first valve; the reflux pump is connected to the upper part of the refining tower through the second valve; the cooling unit is connected to the vacuum pump; the lower part of the refining tower is connected to the upper part of the reboiler, the top of the reboiler is connected to the middle part of the refining tower, the bottom of the reboiler is connected to the bottom of the refining tower, and the reboiler is provided with a steam condensate water outlet on the top; The pressure transmitter is electrically connected to the electronic pressure gauge and the automatic regulating valve.

2. The improved DMAC refining column heating steam pressure stabilizing system of claim 1, wherein: It also includes third valve and fourth valve, third valve and fourth valve are arranged in the both sides of automatic regulating valve.

3. The improved DMAC refining column heating steam pressure stabilizing system of claim 1, wherein: It also includes fifth valve and sixth valve, fifth valve and sixth valve are arranged in the both sides of trap.

4. The improved DMAC refining column heating steam pressure stabilizing system of claim 1, wherein: It also includes seventh valve, seventh valve is parallelly connected with trap.

5. The improved DMAC refining column heating steam pressure stabilizing system of claim 1, wherein: It also includes eighth valve, eighth valve is arranged between cooling unit and vacuum pump.

6. An improved DMAC refining column heating steam pressure stabilizing system as claimed in claim 1, wherein: The cooling unit includes first cooler and second cooler, the top of the refining tower is connected to the air inlet of the first cooler, the air outlet of the first cooler is connected to the air inlet of the second cooler, and the air outlet of the second cooler is connected to the vacuum pump; the condensate water outlet of the first cooler and the condensate water outlet of the second cooler are all connected to the top of the reflux tank.

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