Compressor slugging protection device and method therefor

Claim 1

A method for preventing damage to a compressor due to slugging which comprises the steps of: electrically detecting vibrations due to a slugging compressor; converting said vibrations into corresponding electrical signals; limiting the frequency band of said electrical signals to a predetermined pass band; rectifying and filtering said pass band to produce a direct current electrical signal which is proportional to the energy of the signal in said pass band; comparing said direct current signal to a reference signal which corresponds to the energy of the pass band of a normally operating compressor to identify slugging vibrations; and disabiling said compressor responsive to said slugging vibration detection.

Claim 2

A method for preventing damage to a compressor due to slugging which comprises the steps of: electrically detecting vibrations due to a slugging compressor; converting said vibrations into corresponding electrical signals; limiting the frequency band of said electrical signals to a predetermined pass band; rectifying and filtering said pass band to produce a direct current electrical signal which is proportional to the energy of the signal in said pass band; comparing said direct current signal to a reference signal which corresponds to the energy of the pass band of a normally operating compressor to identify slugging vibrations; and disabiling said compressor responsive to said slugging vibration detection.

Claim 3

A method for detecting compressor slugging which comprises the steps of: detecting compressor vibrations; converting said vibrations into corresponding electrical signals; limiting the frequency band of said electrical signals to a predetermined pass band; rectifying and filtering said pass band to produce a direct current electrical signal which is proportional to the energy of the signal in said pass band; comparing said direct current signal to a reference signal which corresponds to the energy of the pass band of a normally operating compressor.

Claim 4

A method for detecting compressor slugging which comprises the steps of: detecting compressor vibrations; converting said vibrations into corresponding electrical signals; limiting the frequency band of said electrical signals to a predetermined pass band; rectifying and filtering said pass band to produce a direct current electrical signal which is proportional to the energy of the signal in said pass band; comparing said direct current signal to a reference signal which corresponds to the energy of the pass band of a normally operating compressor.

Claim 6

A method for detecting compressor slugging which comprises the steps of: monitoring the sounds made by a compressor; converting said sounds into corresponding electrical signals; limiting the frequency band of said electrical signals to a predetermined pass band; rectifying and filtering said pass band to produce a direct current electrical signal which is proportional to the energy of the signal in said pass band; comparing said direct current signal to a reference signal which corresponds to the energy of the pass band of a normally operating compressor.

Claim 7

A method for detecting compressor slugging which comprises the steps of: monitoring the sounds made by a compressor; converting said sounds into corresponding electrical signals; limiting the frequency band of said electrical signals to a predetermined pass band; rectifying and filtering said pass band to produce a direct current electrical signal which is proportional to the energy of the signal in said pass band; comparing said direct current signal to a reference signal which corresponds to the energy of the pass band of a normally operating compressor.

Claim 8

The method of claim no. 4 further comprising the step of timing the state of a signal resulting from said comparison step in the event of a slug detection for purposes of verifying a true slug condition.

Claim 9

An apparatus for preventing damage to a compressor due to slugging which comprises: means for detecting compressor vibrations and for producing an electrical signal which corresponds to said vibrations; means for limiting the frequency band of electrical signals produced by said detecting and signal producing means; means for converting said frequency limited signal to a direct current signal whose magnitude represents the energy of the signal contained within said frequency band; means for producing a direct current reference signal whose magnitude represents the energy contained within said frequency band of a signal corresponding to the vibrations of a normally operating compressor; means for comparing first said direct current signal with said reference direct current signal to determine a slug condition; means for verifying a detected slug condition; means for disabling said compressor responsive to a verified slug condition.

Claim 10

An apparatus for preventing damage to a compressor due to slugging which comprises: means for detecting compressor vibrations and for producing an electrical signal which corresponds to said vibrations; means for limiting the frequency band of electrical signals produced by said detecting and signal producing means; means for converting said frequency limited signal to a direct current signal whose magnitude represents the energy of the signal contained within said frequency band; means for producing a direct current reference signal whose magnitude represents the energy contained within said frequency band of a signal corresponding to the vibrations of a normally operating compressor; means for comparing first said direct current signal with said reference direct current signal to determine a slug condition; means for verifying a detected slug condition; means for disabling said compressor responsive to a verified slug condition.

Claim 11

The apparatus of claim no. 6 wherein the vibration detection means comprises a vibration transducer.

Claim 12

The apparatus of claim no. 6 wherein the vibration detection means comprises an accelerometer.

Claim 13

The apparatus of claim no. 6 wherein the frequency limiting means comprises: a second order Butterworth high pass filter operably connected to said detection and signal production means; a second order Butterworth low pass filter operably connected to said high pass filter.

Claim 14

The apparatus of claim no. 6 wherein the converting means comprises a half-wave rectifier operably connected to said frequency limiting means.

Claim 15

The apparatus of claim no. 6 wherein the reference signal producing means comprises: a current source; a potentiometer operably connected to said current source.

Claim 16

The apparatus of claim no. 6 wherein the reference signal producing means comprises: an analog to digital converter integrated circuit operably connected to said converting means; a digital latch integrated circuit operably connected to said analog to digital converter for storing a digital reference signal; a programmable array logic device operably connected to said digital latch for enabling and disabling said latch.

Claim 17

The apparatus of claim no. 6 wherein the comparing means comprises an operational amplifier being in a comparator configuration and operably connected to said reference signal producing means and said converting means.

Claim 18

The apparatus of claim No. 6 wherein the comparing means comprises a multi-bit digital comparator integrated circuit operably connected to said converting means and said reference signal producing means.

Claim 19

The apparatus of claim No. 6 wherein the verification means comprises a time delay circuit responsive to said comparing means for preventing disablement of said compressor in the case of an invalid slug detection.

Claim 20

The apparatus of claim No. 6 wherein the verification means comprises: a programmable array logic device operably connected to said comparing means for generating a valid slug detection signal; a timing integrated circuit operably connected to said programmable array logic device for generating a time delay for timing the duration of a slug signal generated by said comparing means.

Claim 21

The apparatus of claim No. 6 wherein the disabling means comprises a relay responsive to said verification means and operably connected between a current source and said compressor, for disabling said compressor in the event of a slug detection.

Claim 22

An apparatus for preventing damage to a compressor due to slugging which comprises: an accelerometer for detecting compressor vibrations and for producing an electrical signal which corresponds to said vibrations; a high pass filter operably connected to said accelerometer, for filtering out signal frequencies below a predetermined frequency; a low pass filter operably connected to said high pass filter, for filtering out signal frequencies above a predetermined frequency; a half-wave rectifier operably connected to said low pass filter for converting the filtered signal to a direct current signal which corresponds to the energy of the filtered signal; a reference voltage source which corresponds to the energy of a signal in the same frequency band as said filtered signal as would be produced by a normally operating compressor; a comparator operably connected to said half-wave rectifier and said reference voltage source for comparing relative signal levels; a time delay circuit operably connected to said comparator for verifying a slug detection; a relay operably connected between a current source and said compressor and responsive to said verified slug detection for disabling said compressor in the event of a slug detection.

Claim 23

An apparatus for preventing damage to a compressor due to slugging which comprises: an accelerometer for detecting compressor vibrations and for producing an electrical signal which corresponds to said vibrations; a high pass filter operably connected to said accelerometer, for filtering out signal frequencies below a predetermined frequency; a low pass filter operably connected to said high pass filter, for filtering out signal frequencies above a predetermined frequency; a half-wave rectifier operably connected to said low pass filter for converting the filtered signal to a direct current signal which corresponds to the energy of the filtered signal; a reference voltage source which corresponds to the energy of a signal in the same frequency band as said filtered signal as would be produced by a normally operating compressor; a comparator operably connected to said half-wave rectifier and said reference voltage source for comparing relative signal levels; a time delay circuit operably connected to said comparator for verifying a slug detection; a relay operably connected between a current source and said compressor and responsive to said verified slug detection for disabling said compressor in the event of a slug detection.

Claim 24

An apparatus for preventing damage to a compressor due to slugging which comprises: an accelerometer for detecting compressor vibrations and for producing and electrical signal which corresponds to said vibrations; a high pass filter operably connected to said accelerometer, for filtering out signal frequencies below a predetermined frequency; a low pass filter operably connected to said high pass filter, for filtering out signal frequencies above a predetermined frequency; a half-wave rectifier operably connected to said low pass filter for converting the filtered signal to a direct current signal which corresponds to the energy of the filtered signal; an analog to digital converter integrated circuit operably connected to said half-wave rectifier for converting said direct current signal to a multi-bit digital signal whose magnitude represents the level of said direct current signal; a digital latching integrated circuit operably connected to said analog to digital converter for storing a multi-bit digital reference signal which corresponds to the energy in the pass band of a normally operating compressor; a multi-bit digital comparator integrated circuit operably connected at its inputs to said analog to digital converter and said digital latch for comparing the multi-bit digital signal of said analog to digital converter to the multi-bit reference signal of said digital latch for the purpose of slug detection; a programmable array logic device operably connected to said digital comparator and said digital latch for verifying a slug detection signal and controlling said latch; a plurality of timing integrated circuits operably connected to said programmable array logic device for generating various length time delays, said timing integrated circuits further being responsive to said programmable array logic device; a digital decoder integrated circuit operably connected to said programmable array logic device for decoding its output and distributing control signals therefrom; a relay operably connected between a current source and said compressor, and responsive and connected to said decoder, for disabling said compressor in the event of a verified slug detection.

Claim 25

An apparatus for preventing damage to a compressor due to slugging which comprises: an accelerometer for detecting compressor vibrations and for producing and electrical signal which corresponds to said vibrations; a high pass filter operably connected to said accelerometer, for filtering out signal frequencies below a predetermined frequency; a low pass filter operably connected to said high pass filter, for filtering out signal frequencies above a predetermined frequency; a half-wave rectifier operably connected to said low pass filter for converting the filtered signal to a direct current signal which corresponds to the energy of the filtered signal; an analog to digital converter integrated circuit operably connected to said half-wave rectifier for converting said direct current signal to a multi-bit digital signal whose magnitude represents the level of said direct current signal; a digital latching integrated circuit operably connected to said analog to digital converter for storing a multi-bit digital reference signal which corresponds to the energy in the pass band of a normally operating compressor; a multi-bit digital comparator integrated circuit operably connected at its inputs to said analog to digital converter and said digital latch for comparing the multi-bit digital signal of said analog to digital converter to the multi-bit reference signal of said digital latch for the purpose of slug detection; a programmable array logic device operably connected to said digital comparator and said digital latch for verifying a slug detection signal and controlling said latch; a plurality of timing integrated circuits operably connected to said programmable array logic device for generating various length time delays, said timing integrated circuits further being responsive to said programmable array logic device; a digital decoder integrated circuit operably connected to said programmable array logic device for decoding its output and distributing control signals therefrom; a relay operably connected between a current source and said compressor, and responsive and connected to said decoder, for disabling said compressor in the event of a verified slug detection.

Claim 26

An apparatus for preventing damage to a compressor due to slugging which comprises: a microphone for detecting compressor sounds and for producing an electrical signal which corresponds to said sounds; a high pass filter operably connected to the microphone, for filtering out signal frequencies below a predetermined frequency; a low pass filter operably connected to said high pass filter, for filtering out signal frequencies above a predetermined frequency; a half-wave rectifier operably connected to said low pass filter for converting the filtered signal to a direct current signal which corresponds to the energy of the filtered signal; a reference voltage source which corresponds to the energy of a signal in the same frequency band as said filtered signal as would be produced by a normally operating compressor; a comparator operably connected to said half-wave rectifier and said reference voltage source for comparing relative signal levels; a time delay circuit operably connected to said comparator for verifying a slug detection; a relay operably connected between a current source and said compressor and responsive to said verified slug detection for disabling said compressor in the event of a slug detection.

Claim 27

An apparatus for preventing damage to a compressor due to slugging which comprises: a microphone for detecting compressor sounds and for producing an electrical signal which corresponds to said sounds; a high pass filter operably connected to the microphone, for filtering out signal frequencies below a predetermined frequency; a low pass filter operably connected to said high pass filter, for filtering out signal frequencies above a predetermined frequency; a half-wave rectifier operably connected to said low pass filter for converting the filtered signal to a direct current signal which corresponds to the energy of the filtered signal; a reference voltage source which corresponds to the energy of a signal in the same frequency band as said filtered signal as would be produced by a normally operating compressor; a comparator operably connected to said half-wave rectifier and said reference voltage source for comparing relative signal levels; a time delay circuit operably connected to said comparator for verifying a slug detection; a relay operably connected between a current source and said compressor and responsive to said verified slug detection for disabling said compressor in the event of a slug detection.

Claim 28

An apparatus for preventing damage to a compressor due to slugging which comprises: a microphone for detecting compressor sounds and for producing an electrical signal which corresponds to said sounds; a high pass filter operably connected to said accelerometer, for filtering out signal frequencies below a predetermined frequency; a low pass filter operably connected to said high pass filter, for filtering out signal frequencies above a predetermined frequency; a half-wave rectifier operably connected to said low pass filter for converting the filtered signal to a direct current signal which corresponds to the energy of the filtered signal; an analog to digital converter integrated circuit operably connected to said half-wave rectifier for converting said direct current signal to a multi-bit digital signal whose magnitude represents the level of said direct current signal; a digital latching integrated circuit operably connected to said analog to digital converter for storing a multi-bit digital reference signal which corresponds to the energy in the pass band of a normally operating compressor; a multi-bit digital comparator integrated circuit operably connected at its inputs to said analog to digital converter and said digital latch for comparing the multi-bit digital signal of said analog to digital converter to the multi-bit reference signal of said digital latch for the purpose of slug detection; a programmable array logic device operably connected to said digital comparator and said digital latch for verifying a slug detection signal and controlling said latch; a plurality of timing integrated circuits operably connected to said programmable array logic device for generating various length time delays, said timing integrated circuits further being responsive to said programmable array logic device; a digital decoder integrated circuit operably connected to said programmable array logic device for decoding its output and distributing control signals therefrom; a relay operably connected between a current source and said compressor, and responsive and connected to said decoder, for disabling said compressor in the event of a verified slug detection.

Claim 29

An apparatus for preventing damage to a compressor due to slugging which comprises: a microphone for detecting compressor sounds and for producing an electrical signal which corresponds to said sounds; a high pass filter operably connected to said accelerometer, for filtering out signal frequencies below a predetermined frequency; a low pass filter operably connected to said high pass filter, for filtering out signal frequencies above a predetermined frequency; a half-wave rectifier operably connected to said low pass filter for converting the filtered signal to a direct current signal which corresponds to the energy of the filtered signal; an analog to digital converter integrated circuit operably connected to said half-wave rectifier for converting said direct current signal to a multi-bit digital signal whose magnitude represents the level of said direct current signal; a digital latching integrated circuit operably connected to said analog to digital converter for storing a multi-bit digital reference signal which corresponds to the energy in the pass band of a normally operating compressor; a multi-bit digital comparator integrated circuit operably connected at its inputs to said analog to digital converter and said digital latch for comparing the multi-bit digital signal of said analog to digital converter to the multi-bit reference signal of said digital latch for the purpose of slug detection; a programmable array logic device operably connected to said digital comparator and said digital latch for verifying a slug detection signal and controlling said latch; a plurality of timing integrated circuits operably connected to said programmable array logic device for generating various length time delays, said timing integrated circuits further being responsive to said programmable array logic device; a digital decoder integrated circuit operably connected to said programmable array logic device for decoding its output and distributing control signals therefrom; a relay operably connected between a current source and said compressor, and responsive and connected to said decoder, for disabling said compressor in the event of a verified slug detection.

Claim 30

A method for preventing damage to a compressor due to slugging which comprises the steps of: electrically monitoring the sound made by a compressor for slugging sounds; disable said compressor responsive to said slugging sounds wherein the monitoring step further comprises: converting said sounds into corresponding electrical signals; limiting the frequency band of said electrical to a predetermined pass band; rectifying and filtering said pass band to produce a direct current electrical signal which is proportional to the energy of the signal in said pass band; comparing said direct current signal to a reference signal which corresponds to the energy of the pass band of normally operating compressor.

Claim 31

A method for preventing damage to a compressor due to slugging which comprises the steps of: electrically monitoring the sound made by a compressor for slugging sounds; disable said compressor responsive to said slugging sounds wherein the monitoring step further comprises: converting said sounds into corresponding electrical signals; limiting the frequency band of said electrical to a predetermined pass band; rectifying and filtering said pass band to produce a direct current electrical signal which is proportional to the energy of the signal in said pass band; comparing said direct current signal to a reference signal which corresponds to the energy of the pass band of normally operating compressor.