Boiler blowdown monitoring system and process for practicing same

• US 4,639,718 A
• Filed: 02/25/1985
• Issued: 01/27/1987
• Est. Priority Date: 04/02/1984
• Status: Expired due to Fees

• Current Assignee: Ashland Incorporated (Bank of Montreal)
• Original Assignee: OLIN Corporation
• Inventors: Gasper, Kenneth E.
• Primary Examiner(s): Swann, III, Glen R.
• Application Number:
  US06/705,179
• Time in Patent Office: 701 Days
• Field of Search: 340/679, 340/627, 340/603, 340/540, 210/696, 210/746, 210/739, 210/85
• US Class Current: 340/603
• CPC Class Codes: C02F 1/685 Devices for dosing the additives
• CPC Class Codes: G05D 21/02 characterised by the use of electric means

Abstract

A boiler blowdown monitoring system wherein the conductivity of the water in the boiler blowdown line is monitored to determine if it exceeds either a preset maximum or minimum level. The system includes a blowdown sensor, a blowdown valve, a blowdown controller and an interrogation means. The water conductivity is sensed by the sensor located on the blowdown line and transmitted to the interrogation means (e.g. microprocessor) through the boiler blowdown controller. If the sensor senses a water conductivity level above a preselected maximum conductivity level or below a preselected minimum conductivity level after a predetermined time period has passed since the boiler blowdown valve was opened, then an alarm signal is sent to the boiler operator.

Claims

1. A process for monitoring a boiler blowdown operation, which comprises the steps of:

(a) generating a first output signal from a boiler blowdown controller to a boiler blowdown valve in a blowdown line, a boiler blowdown sensor in said blowdown line and an interrogation means simultaneously when a predetermined condition exists;

said first output signal causing;

(i) said blowdown valve to open to release water from said blowdown line;

(ii) said blowdown sensor to start sensing the conductivity of the water in said blowdown line; and

(iii) said interrogation means to start an interrogation sequence;

ring said water conductivity measurements

(b) transferring said water conductivity measurements from said blowdown sensor to said blowdown controller;

(c) generating a second output signal from said controller to said blowdown valve, said blowdown sensor and said interrogation means simultaneously when said water conductivity measurement is at a predetermined first (optimum) level, said second output signal causing;

(i) said blowdown valve to close and thereby stop water from leaving said blowdown line;

(ii) said blowdown sensor to stop sensing water conductivity; and

(iii) said interrogation means to stop said interrogation sequence;

(d) generating a third output signal from said controller to said interrogation means when said water conductivity measurement exceeds a predetermined second (maximum) level or is below predetermined third (minimum) level;

said third output signal causing said interrogation means to generate an alarm signal to an alarm annunciation means if said third output signal is generated after a predetermined time period following said first output signal and before said second output signal.

2. The process of claim 1 wherein step (a) occurs only after the elapse of a preselected amount of time from the generation of the previous first output signal.

3. A boiler blowdown monitoring system comprising:

(a) a boiler blowdown valve located in a boiler blowdown line for releasing boiler water during blowdown operation;

(b) a boiler blowdown sensor located in said blowdown line for sensing the conductivity of the water in said blowdown line;

(c) a boiler blowdown controller for generating first, second and third output signals;

(i) said first output signal being generated to said blowdown valve, said blowdown sensor and an interrogation means simultaneously when a predetermined condition exists and being capable of (aa) causing said blowdown valve to open to release water, (bb) causing said blowdown sensor to start sensing said water conductivity and to start tranferring water conductivity measurements to said controller, and (cc) causing said interrogation means to start an interrogation sequence;

(ii) said second output signal being generated to said blowdown valve, said blowdown sensor and said interrogation means simultaneously when said sensor senses a preselected first (optimum) conductivity level and being capable of (aa) causing said blowdown valve to close, (bb) causing said blowdown sensor to stop sensing and to stop transferring conductivity measurements to said controller, and (cc) causing said interrogation means to stop said interrogation sequence;

(iii) said third output signal being generated to said interrogation means when said sensor senses a conductivity level above a preselected second (maximum) conductivity level or below a preselected third (minimum) conductivity level;

(d) said interrogation being capable of sensing said first output signal, said second output signal, and said third output signal, and capable of performing an interrogation sequence, said interrogation sequence comprising;

(i) waiting a predetermined time period after the sensing of said first output signal, then generating an alarm signal to an alarm annunciating means if said third output signal is sensed; and

(ii) ending said interrogation sequence when said second output signal is sensed.

4. The monitor system of claim 3 wherein said interrogation means is an interface module comprising a microprocessor capable of receiving said first, second and third output signals, time-delay switch circuitry to determine the predetermined time period from the first output signal before said interrogation sequence begins, and an open/closed selector switch circuitry to determine the active status of said output signals.