The use of carbon dioxide instead of Freon (HFCs) foaming to produce extruded board technology is listed in the “National Key Low Carbon Technology Catalogue”
Source: reprinted in “building energy efficiency” Journal | Author: peak sun | Published: 2019-02-17 | 291 views
The “National Key Low-carbon Technology Catalogue” (second batch) released by the National Development and Reform Commission recently used Ningxia Dingsheng Sunshine Environmental Protection Technology Co., Ltd. (formerly Ningxia Dingsheng Sunshine Insulation Materials Co., Ltd.) to replace the HFCs by foaming to produce extruded board technology. Included in it.
The “National Key Low Carbon Technology Catalogue” (second batch) released by the National Development and Reform Commission recently included the use of carbon dioxide instead of HFCs for foam production and extrusion technology.
The technology uses carbon dioxide instead of HFCs as a blowing agent to achieve fluorine-free production and achieve the goal of eliminating Freon. At present, this technology has been successfully used to construct and renovate three production lines for the production of extruded sheets of freon foam, and another production line of 100 sets of carbon dioxide foam extruded board equipment has been started.
The technology uses a special equipment for carbon dioxide foamed extruded board to stabilize carbon dioxide in a supercritical state through a constant pressure pump. In the first static mixer, the carbon dioxide and the accelerator are thoroughly mixed, and the high-pressure metering pump and the mass flow meter are used to stably inject the carbon dioxide into the first-stage screw through the second static mixer, the third static mixer and the polystyrene plastic ( PS) Achieve grading and thorough mixing to achieve stable carbon dioxide injection and smooth foaming. Carbon dioxide emission reduction is achieved by using carbon dioxide instead of Freon as a blowing agent to avoid high-potential greenhouse gas emissions.
Key technologies: (1) Carbon dioxide modification technology, the accelerator formed by mixing alcohol, alkyl phosphate and distilled water synergistically foams with carbon dioxide to significantly improve the compatibility and expansion ratio of carbon dioxide and PS plastic; (2) High-pressure mixing technology, under the action of 20MPa high pressure, carbon dioxide and accelerator in the high-pressure mixer, through the splitting → confluence → rotation → re-distribution → re-combination, repeated action, so that carbon dioxide and accelerator (gas, liquid) are fully mixed; (3) Supercritical control technology consists of a carbon dioxide constant pressure thermostat and a carbon dioxide steady-state injection device to form a carbon dioxide constant pressure system, so that carbon dioxide is stably maintained in a supercritical state during the injection process, and its solvency is liquid and gaseous. 100 times; (4) Melt static mixing technology In order to prevent carbon dioxide escape during the transportation and extrusion process, a two-stage static mixer was developed to be installed on the screw to keep the material in a fully mixed state.
The main technical indicators of the product: compressive strength 20 0 k Pa, tensile strength 0.15kPa, dimensional stability 0.16, thermal conductivity 0.030W / (m · K), combustion performance B1.
Special equipment for carbon dioxide foam extrusion board, including carbon dioxide front end constant pressure pump, carbon dioxide supply device, accelerator supply device, material conveying device, first static mixer, first-stage melting screw, second static mixer, second stage An extrusion screw, a third static mixer, and a forming die.
In 2013, the technology was certified by the Science and Technology Department of Ningxia Hui Autonomous Region and obtained four national utility model patents. Typical users include Shijiazhuang Gongmei New Building Materials Factory, Yantai Desai Machinery Manufacturing Co., Ltd., and Ningxia Dingsheng Sunshine Insulation Materials Co., Ltd.
At present, China has more than 1,000 extruded board production lines, and more than 95% use Freon for foaming. Since the greenhouse effect potential of Freon is hundreds of times to tens of thousands of times of carbon dioxide, it will have a greater impact on the environment.
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