The Babcock & Wilcox Company

Bailey Meter Company

Robert E Pocock

Marion A Keyes, Iv

Thomas L Bohl

Michael P Lukas

David F Ross

Marshall H Cooper

A safety control system is disclosed for a coal pulverizer utilizing the measurements of net oxygen and carbon monoxide measurements of the pulverizer atmosphere. First levels of net oxygen and rate of carbon monoxide change are utilized in a control logic system to actuate alarms and automatic inerting of the pulverizer is accomplished utilizing a second level of net oxygen measurement and absolute carbon monoxide level in the pulverizer.

Safety system for coal pulverizers

A system for minimizing combustion operation losses includes measuring a load index for the combustion operation which is proportional to the fuel demand or the output thereof, measuring an amount proportional to the air heating losses of the combustion operation and measuring an amount which is proportional to the fuel loss of the operation. The air heating loss is measured by multiplying a flue temperature by an amount of unburned oxygen in the flue gas. This quantity is multiplied by a cost factor for such air heating and the load index. The fuel loss is obtained by measuring an amount of by-product in the flue gas as well as the opacity of the flue gas. These are multiplied by appropriate cost factors which in the case of opacity is proportional to a fine that would be due for violating certain limits for the opacity. Minimum values are found for the fuel loss and air heating loss quantities, as air demand to the combustion operation is changed. A minimum for the sum of the fuel and air heating losses is also obtained with the air demand of the combustion operation being set so that all of the losses are as low as possible. In this way the costs of undesired air heating, unburned by-products as well as potential violation of flue gas characteristic limits are utilized in determining the most economical air demand for the combustion operation.

Loss minimization combustion control system

A method for controlling a process heater in which a required heat demand is computed based on the enthalpy of the feed stock and the desired enthalpy of the final product, and then used as a feedforward portion of the fuel control. A second embodiment of the invention is based on the assumption that the feed stock enthalpy changes slowly or infrequently. In this embodiment fuel heating value changes are used as a feedforward portion of the fuel control.

Process heater control

A control system for controlling the fuel/air ratio of a fuel/air mixture for a combustion process which produces flue gases having a combustible content and an oxygen content, comprises selecting desired combustible and oxygen contents for the flue gases which correspond to efficient combustion, simultaneously sensing both actual combustion and actual oxygen content in the flue gases, and controlling the fuel/air ratio in accordance only with the sensed combustible and oxygen content to adjust the ratio until the selected set points are reached. The combustible content can be utilized to regulate the oxygen content set point.

System for controlling combustibles and O.sub.2 in the flue gases from

A filter assembly (10) adapted for use with a gas sample analyzing system. The filter is in the form of a flexible sleeve (20) formed from a heat resistant ceramic material which is received on an adapter (12) which fits over a probe (14) of the analyzing system. A V-shaped deflector plate (18) is attached to the adapter (12) beneath the filter and prevents the gas flow which is being sampled from impinging directly on the filter. The deflector plate (18) also sets up gas currents around the filter which cause the filter to flex or flutter, thus dislodging particulate material which tends to become trapped in the filter material.

Flexible filter

A gas sampling system is provided having a combustibles detector and an oxygen detector supplied from a common sample line by their own individual aspirators. The aspirators are sized to allow the one aspirator to overpower the second aspirator whenever the common sample inlet is blocked a predetermined amount to thereby cause oxygen rich supply air to flow through the oxygen detector causing the oxygen detector to register an abnormal condition as an indication of blocked sample inlet.

Gas sampling system having a flow indicator

A gas sampling analyzing system is provided whereby flue or process gasses are aspirated from a process duct to an analyzer and are therefrom returned back to the process duct to prevent condensation at the system exhaust. The sampling analyzing system is enclosed in an internally heated manifold to prevent condensation of the sampled gas and insure an accurate analysis by the system. The sampling analyzing system has an analyzer assembly connected in parallel with a drop tube with the combination being connected to a sample probe on one side and to a supply air operated aspirator on the other side. The parallel drop tube allows a high flow rate to be maintained between the sample probe and the aspirator to ensure a faster system response to changes in concentrations of the flue or process gasses.

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Highland Heights, OH, United States of America

Robert E Pocock