摘要:
A method for feeding a dry pulverized solid material such as coal or limestone into a high pressure combustor is disclosed which employs a high pressure combustor is disclosed which employs a high pressure dry solids pump. The material is first pulverized and transported with air to a separator. The separated solids are temporarily accumulated and fed to one or more dry solids pump which continuously discharge the compact solids at high pressure into a gas mixing chamber. The compact solids are mixed with transport air as a dense phase for transport to the high pressure combustor.
摘要:
This invention relates to a combustion control apparatus for a powdered coal-fired furnace that monitors noxious substances contained within the burning waste gases, unburned substances within the ash and the power data of a pulverizing mill in order to operate the combustion furnace safely and efficiently. The combustion control apparatus infers from the current states or data optimal control amounts that will maintain within the minimum allowable ranges the noxious nitrogen oxides and the in-ash unburned substances that affect the combustion efficiency-and thereby controls the combustion furnace with good stability. The combustion control apparatus qualitatively evaluates as fuzzy quantities the density data of the nitrogen oxides contained within the exhaust gases of the unburned substances contained within the ash, and the power data of the pulverizing mill. Based upon the evaluation results a fuzzy inference is formed so as to determine the optimum control amount of the two-stage combustion air ratio for minimizing the nitrogen oxides and also the optimum control amount for the fine/coarse gain separator so as to extract powdered coal of a grain size most effective for minimizing the unburned substances within the ash.
摘要:
Apparatus for preparing in a circulating fluid bed boiler fuel material that is fed to the boiler with a moisture content that is normally high enough to plug grinding apparatus needed to grind the fuel material to a particulate size for combustion, operating the boiler and grinding apparatus in cooperation so that heat energy at a high temperature is borrowed from the boiler for drying the fuel material at the grinding apparatus and returning the heat energy in the form of steam so there is no net loss of heat energy. The system provides that hot gases discharged from the boiler are fed into the grinding apparatus for drying the incoming moisture containing fuel material before it is conveyed to the boiler as a fuel, and controlling the boiler and grinding apparatus, with or without sorbent, so that the boiler fuel demand is independent of the quantity of fuel material in the grinding apparatus and the rate of grinding of the fuel material is maintained at a predetermined pressure differential in the grinding apparatus.
摘要:
A method of controlling the operation of a pulverizer includes detecting the type of fuel being supplied to the pulverizer. At least one characteristic of the fuel is determined by a combination of measurements and calculations. One characteristic is moisture content which distinguishes one type of fuel, in particular, one type of coal, from another. The feeding rate of the fuel to the pulverizer is selected from a curve which plots primary air flow against percentage of rating for the pulverizer. This curve is constant for the pulverizer despite the types of fuel used.
摘要:
A control system (40) particularly suited for effecting control over the fineness of the particles that are gound, i.e., pulverized, in a bowl mill (10) of the type that is designed to be employed for purposes of pulverizing coal. The subject control system (40) is operatively connected in circuit relation with the conveying means (64) by means of which the particles are conveyed from the bowl mill (10) after being ground therewithin. In addition, the subject control system (40) is also operatively connected with the controls (58, 60) of the bowl mill (10). Accordingly, the subject control system (40) is operative to make measurements of the particles being discharged from the bowl mill (10) and based on the information obtained from such measurements effect the changes in the control settings of the bowl mill (10) as required.
摘要:
Apparatus for simultaneously grinding coal and dolomite to a size suitable for fluid bed combustors in which the grinding mill is modified to allow for the formation in the mill of a bed of the mixed coal and dolomite which reduces the tendency of dolomite to fracture and produce excess of fine particles thereby optimizing the grinding conditions for both coal and dolomite, and a method of reducing coal and dolomite simultaneously in a common mill and in predetermined proportions for optimum reduction of each material.
摘要:
A solid fuel burner especially useful in a system for pulverizing and burning solid fuel, such as coal or other fossil fuel, that is characterized by a possible turndown ratio of up to at least fifteen to one. The burner includes a valved firing nozzle having a firing conduit with firing orifice and internal turbulating means for a mixture of primary air and pulverized solid fuel, and a controlled secondary air supply. A movable valve element, preferably in the form of a double-taper-ended diffuser positioned downstream from the firing orifice, controls the outflow of a turbulent stream of the mxied primary air and fuel from the firing orifice into an ignition chamber and controls flame shape.
摘要:
Apparatus for preparing fuel for delivery to a boiler or place where it is burned in which a grinding mill and a particle sizing classifier are operated to deliver fuel of a substantially uniform size, and means to operate the mill and classifier independently of the rate of supply of the fuel but in response to the differential pressure of the fluid bed depth in the mill. 7
摘要:
A plurality of first logic processors are interconnected in a "ring" type network and individually exercise control over similar equipment group subsystems which individually contribute to the operation of an overall system. Each of the interconnected processors, in addition to its primary control function, monitors the safety of operation of the equipment group with which associated and the safety of operation of a "neighboring" equipment group. Redundant safety checks are thus performed on each equipment group and any discrepancies in the results of such safety checks are enunciated. A pair of further logic processors, in addition to performing other control functions including scheduling the operation of the individual equipment groups, redundantly check the safety of operation of the overall system.