Plastics Granulate Plant Startup Control via Screw Position Feedback
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Solution Overview
Problem
Existing processing plants for producing plastics material granulate face challenges during startup, as the discharged hot plastics material poses safety risks and requires laborious disposal, and the introduction of molten plastics into granulating devices can lead to clogging or solidification issues without precise timing.
Innovation Solution
A method and processing plant that utilize measuring signals to determine the conveying position of plastics material in the screw machine, allowing for timed activation of the granulating device, ensuring simultaneous introduction of molten plastics and cooling water, eliminating the need for a start-up valve and preventing clogging or overheating by using a spray mechanism to atomize the water and cool the granulating blades.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a start-up valve is used to discharge molten plastics material during startup, then the plastics material can be discharged from the screw machine, but the discharged hot plastics material poses safety risks and requires laborious disposal
Solution Approach 1:
The invention extracts and eliminates the start-up valve from the system. Instead of using a valve to discharge molten plastics material during startup, the system directly introduces the molten material into the granulating device where it is immediately cooled and granulated, thereby removing the source of safety hazards associated with discharging hot material.
Solution Approach 2:
The granulating device serves as an intermediary between the screw machine and the final product. By introducing granulating water and cutting blades into the granulating device during startup, the molten plastics material is immediately transformed from a hazardous hot state into a safe granulated state, mediating the transition and eliminating safety risks.
2Productivity
If molten plastics material is introduced into the granulating device without precise timing, then the granulating device can process the material, but clogging or solidification issues occur in the nozzle openings
Solution Approach 1:
The invention applies preliminary action by activating the granulating device, introducing granulating water, and positioning cutting blades before the molten plastics material arrives at the granulating device. This ensures that the granulating device is ready to immediately process the material, preventing clogging and solidification in the nozzle openings.
Solution Approach 2:
The control device monitors the startup process and uses feedback signals to determine when the molten plastics material has reached the granulating device. Based on this feedback, the control device activates the granulating device at the precise moment needed, ensuring reliable operation without clogging.
3Ease of operation
If the granulating device is activated too early during startup, then the granulating device is ready to process material, but the plastics material gums up the cutting mechanism
Solution Approach 1:
The control device uses feedback from sensors that detect the presence and position of molten plastics material to determine the optimal moment to activate the granulating device. This feedback mechanism prevents premature activation that would cause the cutting mechanism to gum up with molten material.
Solution Approach 2:
The startup process is made dynamic by continuously monitoring the state of the plastics material and adjusting the activation timing of the granulating device accordingly. The system adapts to the actual progress of the molten material through the screw machine, ensuring the granulating device is activated at the precise moment when material is present, preventing gumming up.
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 enables a safe and efficient startup process without operational disturbances, ensuring the granulating device is properly initiated, reducing waste and safety risks by synchronizing the introduction of plastics and water, thus optimizing the start-up process.
Implementation Method 1
using a spray mechanism to atomize the water and cool the granulating blades
Implementation Method 2
atomize the water and cool the granulating blades
Implementation Method 3
simultaneous introduction of molten plastics and cooling water
Data Source
AI summary
In a processing plant for producing plastics material granulate, the start-up takes place in such a way that a screw machine is firstly driven by means of a drive device and then plastics material to be processed is fed by means of a metering device into the screw machine. At least one conveying position of the plastics material in the screw machine is determined by means of a control device by evaluating at least one measuring signal. Depending on the conveying position determined, a granulating device is activated and put into operation. The method according to the invention allows a direct start-up of the processing plant without the use of a start-up valve. This ensures an easy and safe start-up of the processing plant.