CN-121990638-A - Heat pump rectifying device and polyvinyl alcohol waste liquid recycling device

Abstract

The invention relates to chemical equipment and provides a heat pump rectifying device and a recovery device of polyvinyl alcohol waste liquid, wherein the heat pump rectifying device comprises a rectifying tower (1), a compressor (2) and a tower kettle reboiler (3), a gas phase outlet at the top of the rectifying tower (1) is connected with a gas inlet of the compressor (2), a gas outlet of the compressor (2) is connected with a heat source inlet of the tower kettle reboiler (3), a kettle liquid outlet of the rectifying tower (1) is connected with the tower kettle reboiler (3) through a circulating pump (5), and kettle liquid of the tower kettle reboiler (3) flows back to the rectifying tower (1). The invention can effectively improve the utilization rate of the steam at the top of the rectifying tower, reduce the heat supply at the bottom of the rectifying tower, reduce the consumption of cold energy at the top of the rectifying tower and has obvious energy-saving effect.

Inventors

• LUO JIANGQIN
• JI ZHENLIN
• ZHANG FEIXIONG
• LIU ZHIYONG
• LI CHUNYU
• ZHAO ZHONGHAN
• FAN LIN
• ZHANG LIJUAN

Assignees

• 内蒙古双欣环保材料股份有限公司
• 内蒙古双欣高分子材料技术研究院有限公司

Dates

Publication Date

20260508

Application Date

20260401

Claims (9)

1. 1. The utility model provides a heat pump rectifying device, its characterized in that includes rectifying column (1), compressor (2) and tower cauldron reboiler (3), rectifying column (1) top of the tower gaseous phase exit linkage the air inlet of compressor (2), the gas outlet of compressor (2) is connected the heat source entry of tower cauldron reboiler (3), the cauldron liquid export of rectifying column (1) is passed through circulating pump (5) and is connected tower cauldron reboiler (3), the cauldron liquid backward flow of tower cauldron reboiler (3) extremely rectifying column (1).
2. 2. The heat pump rectification device according to claim 1, further comprising a liquid seal tank (6) and a flash tank (7), wherein an inlet of the liquid seal tank (6) is connected with the tower reboiler (3), so that the condensed liquid phase of the tower reboiler (3) enters the liquid seal tank (6), a liquid outlet of the liquid seal tank (6) is connected with the flash tank (7), and a gas phase outlet of the flash tank (7) is connected with a gas inlet of the compressor (2).
3. 3. Heat pump rectification device according to claim 2, characterized in that the top gas phase outlet of the rectification column (1) is further connected with a distillation condenser (8), the uncondensed gas phase of the distillation condenser (8) is output to a tail gas condenser (9), the condensate outlet of the distillation condenser (8) and the condensate outlet of the tail gas condenser (9) are jointly connected with a distillation tank (10), the distillation tank (10) is connected to the compressor (2) through a spray pipeline, so as to be suitable for spraying condensate to the compressor (2) for cooling, and the spray liquid is suitable for being collected and conveyed to the flash tank (7).
4. 4. A heat pump rectification apparatus according to claim 3, characterized in that the condensate outlet of the flash tank (7) is connected to the inlet of the distillation condenser (8).
5. 5. A heat pump rectification apparatus according to claim 3, wherein the outlet of the tank reboiler (3) and/or the outlet of the liquid seal tank (6) is connected to the inlet of the off-gas condenser (9).
6. 6. A heat pump rectification apparatus according to claim 3, further comprising a muffler (11), said muffler (11) being arranged between said compressor (2) and said tank reboiler (3), a bottom condensate outlet of said muffler (11) being connected to said flash tank (7), said muffler (11) being configured to collect said spray liquid and to deliver it into said flash tank (7).
7. 7. A heat pump rectification device according to claim 3, wherein a first regulating switch (12) is arranged on a pipeline of the top gas phase outlet of the rectification column (1) connected with the air inlet of the compressor (2), and a second regulating switch (13) is arranged on a pipeline of the top gas phase outlet of the rectification column (1) connected with the distillation condenser (8).
8. 8. Heat pump rectification apparatus according to any one of claims 1 to 7, wherein a rectification column reboiler (4) is connected to the bottom of the rectification column (1), the heat source inlet of the rectification column reboiler (4) being connected to an external heat source.
9. 9. A recovery device for polyvinyl alcohol waste liquid, characterized by comprising the heat pump rectifying device according to any one of claims 1 to 8.

Description

Heat pump rectifying device and polyvinyl alcohol waste liquid recycling device Technical Field The invention relates to chemical equipment, in particular to a heat pump rectifying device and a polyvinyl alcohol waste liquid recycling device. Background Rectification is a separation process that separates components of a mixture by utilizing their different volatilities. Rectification is usually carried out in a rectifying tower, and gas-liquid two phases are in countercurrent contact to carry out phase-to-phase heat and mass transfer. The volatile component in the liquid phase enters the gas phase, and the difficult volatile component in the gas phase is transferred into the liquid phase, so that the high-purity volatile component can be obtained at the top of the tower, and the high-purity difficult volatile component can be obtained at the bottom of the tower. The feed liquid is added from the middle part of the tower, the tower section above the feed inlet further concentrates the volatile components in the rising vapor, which is called a rectifying section, and the tower section below the feed inlet extracts the volatile components from the descending liquid, which is called a stripping section. And condensing vapor led out from the top of the tower, wherein a part of condensate is used as reflux liquid and returns to the rectifying tower from the top of the tower, and the rest distillate is the top product. The liquid extracted from the bottom of the tower is gasified by the reboiler, the vapor rises along the tower, and the rest liquid is used as the bottom product. Therefore, refrigeration and heating are needed in the rectification process, and the energy consumption in the production process can be effectively reduced by reasonably arranging the heat recovery process. In order to reduce the production cost of the polyvinyl alcohol production device, the recovery device is provided with a plurality of recovery procedures for saving energy, for example, the methanol purification tower still outputs high-temperature hot water to heat the material of the acetaldehyde crude separation tower reboiler, the distilled gas phase of the acetic acid crude separation tower is directly conveyed to the methyl acetate purification tower, the distilled gas phase of the acetic acid purification tower is used as a heat source of the methyl acetate crude separation tower reboiler, and the like, and although the recovery procedure reduces the steam consumption ratio, along with the continuous improvement of the energy-saving carbon reduction target, the energy-saving space still exists, the energy consumption is reduced, and the market competitiveness is improved. Disclosure of Invention The invention aims to solve the technical problem of providing a heat pump rectifying device and a polyvinyl alcohol waste liquid recovery device, so that the utilization rate of the steam at the top of a rectifying tower can be further improved, the heat supply at the bottom of the tower is reduced, the consumption of cold energy at the top of the tower is reduced, and the energy-saving effect is obvious. In order to solve the technical problems, the invention provides a heat pump rectifying device which comprises a rectifying tower, a compressor and a tower kettle reboiler, wherein a gas phase outlet at the top of the rectifying tower is connected with an air inlet of the compressor, an air outlet of the compressor is connected with a heat source inlet of the tower kettle reboiler, a kettle liquid outlet of the rectifying tower is connected with the tower kettle reboiler through a circulating pump, and kettle liquid of the tower kettle reboiler flows back to the rectifying tower. In some embodiments, the system further comprises a liquid seal tank and a flash tank, wherein an inlet of the liquid seal tank is connected with the tower kettle reboiler, so that condensed liquid phase of the tower kettle reboiler enters the liquid seal tank, a liquid outlet of the liquid seal tank is connected with the flash tank, and a gas phase outlet of the flash tank is connected with an air inlet of the compressor. In some specific embodiments, the top gas phase outlet of the rectifying tower is further connected with a distillation condenser, the non-condensed gas phase of the distillation condenser is output to a tail gas condenser, the condensate outlet of the distillation condenser and the condensate outlet of the tail gas condenser are commonly connected with a distillation tank, and the distillation tank is connected to the compressor through a spraying pipeline so as to be suitable for spraying condensate to the compressor for cooling, and the spraying liquid is suitable for being collected and conveyed to the flash tank. In some embodiments, the condensate outlet of the flash tank is connected to the inlet of the distillate condenser. In some embodiments, the outlet of the tower reboiler and/or the outlet of the liquid seal tank is connected