Heat and Flame Detectors Overview
5 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary purpose of the UV sensing tube in the UV flame detector?

  • To provide electrical connections between components
  • To control the detector's operation
  • To protect the detector from explosions
  • To detect UV light emitted by a flame (correct)
  • How does the UV flame detector activate its alarm?

  • By sensing the sound of a flame
  • When the flame becomes visible to the human eye
  • Through a rise in current due to temperature increase (correct)
  • By detecting pressure changes in the environment
  • What role do program switches play in the UV flame detector?

  • They allow the user to set specific operational criteria (correct)
  • They connect various components electrically
  • They protect against external explosions
  • They add additional sensitivity to the semiconductor
  • Which component of the UV flame detector provides support and stabilization?

    <p>Mounting bracket (D)</p> Signup and view all the answers

    What is a significant feature of the semiconductor used in the UV flame detector?

    <p>It is sensitive to temperature changes (B)</p> Signup and view all the answers

    Flashcards

    UV Flame Detector

    A fire detector that detects flames using ultraviolet light.

    UV Sensing Tube

    Component that detects the UV light emitted by flames.

    Semiconductor

    Material sensitive to temperature changes in the detector.

    Explosion Proof Housing

    Protects the detector from external explosions.

    Signup and view all the flashcards

    Program Switches

    Controls the operational settings of the UV flame detector.

    Signup and view all the flashcards

    Study Notes

    Restorable Semiconductor Line-Type Heat Detectors

    • Uses a sensitive semiconductor material as the sensing element
    • Contains a small central conductor
    • A small current flows when temperatures are normal
    • As temperatures increase, resistance decreases, allowing more current to flow and triggering an alarm
    • Designed for cable trays, conveyors, electrical switchgear, warehouses, mines, pipelines, hangars, etc.

    Non-Restorable Fusible Line-Type Heat Detectors

    • Uses two steel wires separated by heat-sensitive insulation
    • When temperatures reach a threshold, insulation melts, connecting the wires, and initiating an alarm
    • Melted sections require replacement for system restoration
    • Special controls can pinpoint the specific fire location

    UV Flame Detectors

    • Use silicon carbide, aluminum nitrate, or gas-filled tubes as sensing elements
    • Flame's UV radiation ionizes the gas, making it conductive and triggering an alarm
    • Designed to detect UV radiation from a flame

    IR Flame Detectors

    • Use a filter and lens system that screens out unwanted radiant energy
    • Focuses incoming infrared radiation on light-sensitive components
    • Can detect total infrared content or specific frequencies of flame flicker
    • Designed for indoor use and include filtering systems or solar-sensing circuits to avoid false alarms from sunlight
    • Combination UV/IR detectors are more common now, improving accuracy by minimizing false alarms from other sources.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    Explore the different types of heat and flame detectors used in various applications, including semiconductor line-type, fusible line-type, and UV flame detectors. Learn how each detector functions and their specific uses in industries like mining, warehouses, and electrical systems.

    More Like This

    Use Quizgecko on...
    Browser
    Browser