Mine Dusting Machine Roller Shaft Wear Reduction
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Solution Overview
Problem
Conventional dusting devices in coal mines face issues with limestone dust becoming wet and agglomerating due to high humidity, reducing its travel distance and uniformity of coating, and the power source, such as a rubber lagged roller, is prone to breaking and excessive wear due to concentrated load and flexing.
Innovation Solution
A dusting device with a vee bottom tank using an auger and air blower, along with a vibrator for dust movement, and a specially designed discharge structure to maintain dryness, combined with a lagged roller with a shorter length and ceramic tiles for reduced wear, ensures effective delivery of limestone dust and reduces the risk of roller shaft breakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional trickle dusters use ambient air blowers to fluidize limestone dust, then dust is continuously discharged into entries, but the dust absorbs water from humid air causing particles to become heavier and stick together, reducing travel distance and coating uniformity
Solution Approach 1:
The system pre-pressurizes air in a storage tank before introducing it to the dust, ensuring the dust is fluidized and discharged with dry, pressurized air rather than humid ambient air. This preliminary pressurization action prevents the dust from absorbing moisture during the fluidization and discharge process.
Solution Approach 2:
A pressurized air storage tank serves as an intermediary between the ambient air source and the dust discharge system. This intermediary component allows the system to decouple from direct ambient air intake, using stored pressurized air instead to fluidize and transport the dust, thereby preventing moisture contamination.
2Ease of operation
If a long lagged roller is used to power the duster blower by contact with the conveyor belt, then the roller can be driven by the belt, but the concentrated load at the center causes the roller to flex and the shaft to break
Solution Approach 1:
The system segments the power transmission function by using multiple shorter rollers distributed along the conveyor belt width, rather than one long roller. Each shorter roller experiences less bending moment and flexing, preventing shaft breakage while still providing adequate power to drive the blower through belt contact.
Solution Approach 2:
The system applies local quality by positioning rollers at specific locations across the belt width where they can effectively transfer power without experiencing excessive flexing. The shorter roller length and strategic positioning create favorable local mechanical conditions that reduce stress concentration and prevent failure.
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
The solution allows limestone dust to travel further and uniformly coat surfaces while preventing roller flexing and breakage, maintaining effective inertness in mine ventilation and reducing maintenance needs.
Implementation Method 1
The blower discharge air goes into the tank typically up thru the limestone dust and fluidizes the dust
Implementation Method 2
preferably with the addition of a vibrator on at least one sloped side wall to aide in dust movement to the auger
Implementation Method 3
an auger in the bottom of a vee bottom tank
Data Source
AI summary
An apparatus for delivering limestone dust to the outlet of a unique dust discharge structure of a dust hopper (tank) particularly useful in dusting underground coal mine shafts wherein an air blower for pressurizing a dust/air mixture in the discharge structure is powered by a lagged roller engaged and rotatably driven by a conveyor belt and wherein the roller has ceramic tiles partially imbedded in its lagged surface.