Process pressure control in nylon synthesis

A gaseous mixture, liquid technology, applied in the field of continuous polyamide synthesis system, can solve the problems of expensive, expensive production cost brokers, waste generation and so on

Active Publication Date: 2014-11-05
INVISTA TEXTILES (U K) LTD
View PDF5 Cites 5 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Process steam can be broker expensive in terms of production costs and can be environmentally expensive in terms of generating waste and consuming finite resources
Furthermore, process steam based systems cannot be controlled in such a way as to produce high volume, high quality product

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Process pressure control in nylon synthesis
  • Process pressure control in nylon synthesis
  • Process pressure control in nylon synthesis

Examples

Experimental program
Comparison scheme
Effect test

Embodiment

[0079] continuous polymerization process. In the examples given in this section the following methods were carried out. In the continuous nylon 6,6 manufacturing process, adipic acid and hexamethylenediamine are mixed in water in an approximately equimolar ratio in a salt bath to form an aqueous nylon 6,6 salt containing nylon 6,6 salt having about 50% by weight water. mixture. The aqueous salt was transferred to the evaporator at about 105 L / min. The evaporator heats the brine solution to about 125-135°C (130°C) and removes water from the heated brine solution such that the water concentration reaches about 30% by weight. The evaporated salt mixture was transferred to the reactor at about 75 L / min. The reactor brings the temperature of the evaporated salt mixture to about 218-250°C (235°C), allowing the reactor to further remove water from the heated evaporated salt mixture, bringing the water concentration to about 10% by weight, and causing further polymerization of the...

Embodiment 1c

[0087] Example 1c: Finisher with atmospheric leg recirculation and liquid ring vacuum pump.

[0088] A continuous polymerization process is carried out. The exhaust from finisher 208 is routed to exhaust condenser 216 . Vent condenser 216 includes a liquid reservoir 224 fitted with a discharge line. An exhaust line, sometimes called the atmospheric leg, connects to a low point in the reservoir 224 . A pump connected to the atmospheric leg transfers the liquid from the reservoir 224 to the filter and cooler 306 and thereafter returns the fluid to the weir 218 and ejector arranged above the exhaust condenser 216 .

[0089] Vacuum line 420 connects to exhaust condenser 216 at a point above liquid reservoir 224 . Vacuum line 420 is connected to 304 austenitic steel liquid ring vacuum pump 246C which pumps out 1000m 3 / h. The LRVP 246C is vented to a scrubber and thereafter vented to atmosphere. The polymer mixture leaving LRVP246C contained about 0.5 ppm iron, which reduced...

Embodiment 2a

[0090] Example 2a: Comparative example. Finisher with atmospheric leg discharge and mechanical vane pump.

[0091] A continuous polymerization process is carried out. The exhaust from the finisher is sent to an exhaust condenser. The vent condenser includes a liquid reservoir fitted with a discharge line. The discharge line, sometimes called the atmospheric leg, connects to a low point in the reservoir. The liquid in the atmospheric leg is set to the collection tank route. A collection tank, sometimes called a thermal well, consists of a weir and a discharge. Collection tank discharges to sanitary sewer. A separate water supply line is connected to a weir and ejector arrangement located above the exhaust condenser.

[0092] The vacuum line was connected to the exhaust condenser at a point above the liquid reservoir. The vacuum line is connected to a 304 austenitic steel mechanical vane pump which pumps out 1000m 3 / h. The vacuum pump discharges to the scrubber and the...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

A system is configured for continuous polyamide synthesis. The system includes a vent condenser and a vacuum pump. The vent condenser is coupled to a polymerization finisher. The vent condenser has a liquid reservoir and a vent discharge port above a level of the liquid reservoir. The vacuum pump is coupled to the vent discharge port by an intake line. The vacuum pump has an output port and a rotary shaft. A gaseous mixture proximate the vent discharge port is removed at a rate determined by a speed of the rotary shaft. The vacuum pump is configured to have a liquid ring seal.

Description

[0001] Cross References to Related Applications [0002] This application claims the benefit of priority to US Provisional Patent Application No. 61 / 818,240, filed May 1, 2013, the disclosure of which is incorporated herein by reference in its entirety. technical field [0003] The present invention relates to a system configured for continuous polyamide synthesis. Background technique [0004] Polyamides are prepared using a process in which a diamine (for example, hexamethylene-1,6-diamine) and a dicarboxylic acid (for example, adipic acid), sometimes the carboxyl In the form of ammonium acid salt, polymerized under polycondensation conditions (for example, at a temperature in the range of 180°C to 300°C). The condensation reaction produces polyamide (eg, nylon 6,6) and water as a by-product. In some cases, the early steps of the process include concentrating the ammonium carboxylate salt solution before transferring the solution to a reactor. The process of concentrati...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): C08G69/28
CPCC08G69/04C08G69/28
Inventor 查尔斯·R·克尔曼托马斯·A·米奇卡约翰·P·普安萨蒂加里·R·韦斯特
Owner INVISTA TEXTILES (U K) LTD
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products