Booster Hopper Air Cascades for Fast Plastic Granule Heating
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Solution Overview
Problem
Existing methods for heating and drying plastic granules before plasticization are inefficient and can lead to material degradation due to uncontrollable heat exposure and energy waste, particularly when using boosters, which fail to provide sufficient heat energy uniformly and efficiently.
Innovation Solution
A method involving a booster hopper design where process air is selectively blown through plastic granules multiple times in cascades, with varying path lengths and temperatures, ensuring optimal heat transfer just before plasticization, minimizing residence time and preventing material degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If hot process air is blown through plastic granules in a booster hopper to supply heat energy, then the heat input rate increases, but the plastic granules begin to float in the air and can no longer flow to the plasticization point
Solution Approach 1:
The booster hopper is divided into multiple levels with process air barriers at different heights. The process air is introduced at the lower level and forced to flow upward through the plastic granules in a controlled manner, rather than blowing horizontally through the entire material bed. This segmentation of the air flow path prevents granule flotation while ensuring sufficient heat transfer.
Solution Approach 2:
Instead of introducing process air horizontally through the granules (which causes flotation), the air is introduced vertically from the lower level and forced to flow upward through the material. This dimensional change in air introduction direction transforms the flow pattern, allowing heat transfer without disrupting granule flow to the plasticization point.
2Use of energy by moving object
If the flow rate of process air is increased to supply sufficient heat energy, then the energy input rate increases, but the air density decreases and a significantly larger volume of air is required
Solution Approach 1:
The system uses a blower to generate and circulate process air through the booster hopper. The pneumatic system introduces hot air at controlled flow rates and pressures, forcing the air to flow upward through the plastic granules via the process air barriers. This pneumatic approach enables efficient heat transfer with manageable air volumes by controlling air density and flow dynamics.
3Use of energy by moving object
If the residence time of plastic granules in the booster hopper is increased to allow sufficient heat absorption, then the heat energy intake increases, but the risk of material degradation increases
Solution Approach 1:
The process air is continuously circulated through the plastic granules in the booster hopper, maintaining a steady state of heat transfer. The continuous flow of hot air ensures that granules receive sufficient heat energy without being held in the hopper for extended periods. This continuous action allows efficient heat absorption while minimizing residence time-related degradation risks.
Solution Approach 2:
The process air is forced to flow rapidly upward through the plastic granules in a controlled manner, skipping the traditional slow percolation path. This rapid flow through the material bed delivers heat energy quickly to the granules while the air itself moves through the hopper in a short time, minimizing the overall residence time and thus reducing degradation risk.
4Use of energy by moving object
If the temperature of process air is increased to provide more heat energy, then the heat input rate increases, but condensates form at higher temperatures which contaminate the dryer
Solution Approach 1:
The process air is preheated to the required temperature before being introduced into the booster hopper, ensuring that sufficient heat energy is available for immediate heat transfer to the plastic granules. This preliminary heating of the air prevents the need to use excessively high temperatures in the hopper, thereby avoiding condensate formation and contamination of the drying system.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach ensures efficient and uniform heat distribution to plastic granules, reducing energy consumption and material degradation, while maintaining a stable plasticizing process.
Implementation Method 1
the process air is blown through the plastic granules (10) in a booster hopper (11) in a controlled manner, in order to transfer heat energy to the bulk material (10)
Implementation Method 2
the bulk material (10) is dried to a residual moisture content of approximately 20-50 ppm by the flow of warm, dry air
Data Source
Figure 1a
Figure 1b
Figure 2
AI summary
The invention relates to a method and a device for the fast and efficient heating of plastic granulates (10) for preparing for the processing in a plasticization. In order to introduce thermal energy, a gas (6), preferably dried air, is not introduced in the direct countercurrent into the flow of plastic granulates. The gas is introduced, preferably in its still hottest state, in a targeted manner at a freely selectable location for rapid energy introduction. This is preferably carried out at the material outlet (2) of the booster funnel (11). The gas is preferably guided through variably configurable cascades (9) and flows at least twice through the bulk material (10). The velocity of the current can be influenced.