Abstract: A burner control system for controlling the operation of a fuel burner arranged to burn a combination of a supply of fuel and a supply of air is provided. The burner control system is arranged to receive from an exhaust gas analyzer one or more signals, each signal being indicative of the level of an exhaust gas emitted by the fuel burner; receive from a photodetector a signal indicative of a level of electromagnetic radiation output by the flame of the fuel burner; and control at least one of the supply of fuel and the supply of air to the burner based on the one or more signals received from the exhaust gas analyzer and the signal received from the photodetector.

Abstract: The invention provides a condensing boiler 100 including a heat exchanger 160, the heat exchanger including at least one fluid flow cassette 162a, 162b, 163a, 163b, 164a, 164b, each cassette comprising first 181 and second 182 sheets, wherein at least the first sheet has corrugations 185, 186, 187 along a length of the sheet so as to form a number of grooves extending across a width of the sheet, wherein the second sheet is attached against the first sheet so as to enclose the grooves to form a number of fluid flow passageways 193 extending across a width of the cassette in between the first and second sheets, and wherein the cassette is substantially curved across its width such that the fluid flow passageways are substantially curved along their length. The invention also provides a method of manufacturing a heat exchanger or condensing boiler.

Abstract: The invention provides a condensing boiler 100 including a heat exchanger 160, the heat exchanger including at least one fluid flow cassette 162a, 162b, 163a, 163b, 164a, 164b, each cassette comprising first 181 and second 182 sheets, wherein at least the first sheet has corrugations 185, 186, 187 along a length of the sheet so as to form a number of grooves extending across a width of the sheet, wherein the second sheet is attached against the first sheet so as to enclose the grooves to form a number of fluid flow passageways 193 extending across a width of the cassette in between the first and second sheets, and wherein the cassette is substantially curved across its width such that the fluid flow passageways are substantially curved along their length. The invention also provides a method of manufacturing a heat exchanger or condensing boiler.

Abstract: A burner includes a generally cylindrical casing (1) and a burner head (2) mounted within the casing, the burner head including one or more vanes (9) rotatably mounted on the head and rotatable about the head to sweep through a region between the burner head (2) and the casing (1). The vanes (9) each include one or more gas outlets for introducing gas into an air flow through the region.

Abstract: Blowdown of a pressurised steam boiler heated by a burner 1 and including a blowdown flow control valve 17 is controlled by opening the control valve in response to receiving a control signal from a control unit 20 to allow water to leave the boiler. The control unit receives one or more signals indicative of the steam production rate of the boiler and adjusts the amount of blowdown in dependence upon the aggregate steam production.

Abstract: A burner installation includes a stack, a burner, a fuel valve, an air valve and a control device including a store storing burner pairs of values of air and fuel valve settings at firing rates and for controlling air and fuel valve settings. A stack flow regulator adjusts flow of combustion products through the stack and a pressure sensing arrangement monitors pressure of combustion products downstream of the burner. Respective pairs of stack flow regulator setting values and a measured value from the pressure sensing arrangement are stored for pairs of air and fuel valve settings values. The control device receives a feedback signal from the pressure sensing arrangement for comparing an actual pressure value with a stored pressure value and to trim the stack flow regulator setting to cause the actual pressure value from the pressure sensing arrangement to move closer to the stored pressure value.

Abstract: Burner control systems and methods of operating a burner are for a large boiler such as might be used in hospitals, hotels, offices or other large commercial or domestic premises.

Abstract: A burner includes a generally cylindrical casing (1) and a burner head (2) mounted within the casing, the burner head including one or more vanes (9) rotatably mounted on the head and rotatable about the head to sweep through a region between the burner head (2) and the casing (1). The vanes (9) each include one or more gas outlets for introducing gas into an air flow through the region.

Abstract: A burner is operated by providing a monitoring unit and monitoring the firing rate of the burner and feeding an input signal representing the firing rate to the monitoring unit. The respective proportions of gases in exhaust emissions from the burner are monitored and input signals representing the respective proportions are fed to the monitoring unit. From a combination of the input signals representing the firing rate of the burner and the respective proportions of gases in exhaust emissions, the amounts of one or more of the gases emitted from the burner are calculated in the monitoring unit. At least one of the amounts is displayed.

Abstract: A method of controlling the operation of a pressurised steam boiler (50) heated by a burner (20), which includes the steps of a) monitoring the level of water in the boiler (50), b) monitoring the pressure of steam in the boiler (50), c) monitoring the firing rate of the burner (20), and d) controlling the flow rate of water into the boiler (50) having regard to the signals resulting from a) and b) and, at least for some signal conditions, also having regard to signals resulting from c). The level of water is detected by a pair of capacitance probe assemblies (58A and 58B).

Abstract: A method and apparatus for controlling the operation of a pressurized steam boiler heated by a burner. The method includes the steps of monitoring the level of total dissolved solids in water contained in the boiler, monitoring the level of water in the boiler, monitoring the pressure of steam in the boiler, monitoring the firing rate of the burner; controlling the blow down of the boiler having regard to the level of total dissolved solids in water contained in the boiler, and controlling the flow rate of water into the boiler and the firing rate of the burner. All input signals relating to the monitoring steps are passed to a common control unit and all output signals relating to the controlling steps are transmitted from the common control unit.

Abstract: A method and apparatus for controlling the operation of a pressurised steam boiler heated by a burner. The method includes the steps of monitoring the level of total dissolved solids in water contained in the boiler, monitoring the level of water in the boiler, monitoring the pressure of steam in the boiler, monitoring the firing rate of the burner; controlling the blow down of the boiler having regard to the level of total dissolved solids in water contained in the boiler, and controlling the flow rate of water into the boiler and the firing rate of the burner. All input signals relating to the monitoring steps are passed to a common control unit and all output signals relating to the controlling steps are transmitted from the common control unit.

Abstract: A method of controlling the operation of a pressurised steam boiler (50) heated by a burner (20), which includes the steps of a) monitoring the level of water in the boiler (50), b) monitoring the pressure of steam in the boiler (50), c) monitoring the firing rate of the burner (20), and d) controlling the flow rate of water into the boiler (50) having regard to the signals resulting from a) and b) and, at least for some signal conditions, also having regard to signals resulting from c). The level of water is detected by a pair of capacitance probe assemblies (58A and 58B).

Abstract: The flow rate of water into a pressurised steam boiler heated by a burner is controlled by monitoring the level of water in the boiler, monitoring the pressure of steam in the boiler and monitoring the firing rate of the boiler. The level of water in the boiler is measured by a pair of capacitance probes. By controlling the water flow with regard not only to variables relating to the boiler but also variables relating to the burner, it is possible to provide a better control of water flow. Also, by assessing variables relating both to the burner operation and the boiler operation, an assessment of the mass flow rate of steam from the boiler can be made without employing a steam flow meter.

Abstract: The flow rate of water into a pressurized steam boiler heated by a burner is controlled by monitoring the level of water in the boiler, monitoring the pressure of steam in the boiler and monitoring the firing rate of the boiler. The level of water in the boiler is measured by a pair of capacitance probes. By controlling the water flow with regard not only to variables relating to the boiler but also variables relating to the burner, it is possible to provide a better control of water flow. Also, by assessing variables relating both to the burner operation and the boiler operation, an assessment of the mass flow rate of steam from the boiler can be made without employing a steam flow meter.

Abstract: A method of monitoring for the presence of a flame in a burner includes the steps of providing a UV bulb sensor (1) whose electrical output signal in response to a voltage applied across the sensor varies according to the presence or absence of UV light radiating from a burner flame, connecting the sensor across a voltage source (2) which is adjustable, the voltage source being set at a first setting, and monitoring the output signal from the bulb sensor during operation of the burner and automatically altering the setting of the voltage source from the first setting in accordance with the monitored output signal to maintain the output signal within a predetermined range.