System and method for detecting and suppressing dust explosions

A method for detecting and suppressing a dust explosion occurring in a process enclosure, the method comprising the steps of:

• generating with a pressure sensor a pressure signal indicative of a pressure within the process enclosure;
• and
• analyzing with an electronic processing element the pressure signal to determine whether the dust explosion is occurring, wherein analyzing the pressure signal includes—
• sampling the received pressure signal at a higher frequency of approximately between 2 kHz and 20 kHz,
• converting the sampled pressure signal from the higher frequency to a lower frequency of approximately between 500 Hz and 1500 Hz,
• filtering the converted pressure signal with a first filter to remove a first portion of the pressure signal having a rate of increase exceeding a first pre-established maximum magnitude of approximately between 20 bar/s and 40 bar/s,
• filtering the first filtered pressure signal with an intermediate filter between the first and second filters to remove a second portion of the pressure signal having a rate of increase exceeding a second pre-established maximum magnitude of approximately between 5 bar/s and 15 bar/s,
• filtering the intermediate filtered pressure signal with a second filter having a cut-off frequency of approximately between 50 Hz and 120 Hz, a stop band attenuation factor of approximately between 8 and 12, and an end of passband frequency of approximately between 0 Hz and 2 Hz, and
• activating a suppression system if the first filtered pressure signal exceeds a pre-established static pressure threshold value or if the rate of increase of the second filtered pressure signal exceeds a pre-established rate-of-increase threshold value or if the total suppressed pressure predicted on the basis of the first and second filtered pressure signal exceeds a pre-established equipment strength value, each of which indicates, alternatively or additionally, the dust explosion occurring in the process enclosure.

A system for detecting and suppressing a dust explosion occurring in a process enclosure, the system comprising:

• a pressure sensor configured to generate a pressure signal indicative of a pressure within the process enclosure;
• and
• an electronic processing element configured to analyze the pressure signal to determine whether the dust explosion is occurring, wherein the electronic processing element is configured to—
• sample the received pressure signal at a higher frequency,
• convert the sampled pressure signal from the higher frequency to a lower frequency,
• filter the converted pressure signal with a first filter to remove a first portion of the pressure signal having a rate of increase that grows over one millisecond with more than a first pre-established maximum magnitude,
• filter the first filtered pressure signal with an intermediate filter to remove a second portion of the pressure signal having a rate of increase exceeding a second pre-established maximum magnitude,
• filter the intermediate filtered pressure signal with a second filter having a cut-off frequency, a stop band attenuation factor, and an end of passband frequency, and
• activate a suppression system if the first filtered pressure signal exceeds a pre-established static pressure threshold value or if the rate of increase of the second filtered pressure signal exceeds a pre-established rate-of-increase threshold value or if the total suppressed pressure predicted on the basis of the first and second filtered pressure signal exceeds a pre-established equipment strength value, each of which indicates, alternatively or additionally, the dust explosion occurring in the process enclosure.