Abstract: Apparatus to measure the calorific value and/or the Wobbe index of fuel gas supplied along a pipe. A control can operate two outlet valves and cause an inlet valve to be locked in a closed position or be unlocked to stay in a normally open state until the gas pressure in a chamber of predetermined volume reaches a preset pressure difference above the pressure in the pipe. Under direction of the control, a pump moves fuel gas from the pipe into the chamber whilst the outlet valves are closed. Once the pressure in the chamber attains the preset difference, the inlet valve closes automatically to be held locked closed by the control. Certain properties of the gas in the chamber, such as thermal conductivity, specific heat capacity and speed of sound, are measured and corrected to STP conditions. The pump moves two samples of gas into the chamber at two sequential times, each time until the gas pressure therein attains the preset value and the inlet valve again closes automatically in a locked position.

Abstract: A coal slagging gasifier has a gasifying vessel over a quenching chamber partly filled with water below the surface of which a wall of a cylindrical, metal shield dips. The gasifying vessel has a hearth including a slag tap having a slag outlet with a lowermost opening at substantially the same horizontal level as an annular burner and a ring-shaped nozzle. The burner which surrounds the outlet is spaced therefrom and inset into a recess surrounding the outlet, and the nozzle surrounds the burner. Outlet ports from the nozzle project through a ceiling of the shield to direct a flow of combustion sustaining gas vertically downwards into the quenching chamber from the outlet ports and towards the water. An opening in the centre of the shield ceiling exposes the interior of the shield to the burner and the slag tap outlet. The burner separately supplies fuel gas and combustion air.

Abstract: An optical sensor assembly includes a light source, a surface plasmon-sensitive structure for reflecting light, a light detector, and a signal indicator. The light detector receives light that is reflected from the surface plasmon-sensitive structure at an angle which is sensitive to surface plasmon absorption.

Abstract: A molten carbonate high temperature fuel cell contains a hydrocarbon-containing fuel reforming catalyst on a support, where the catalyst is produced by reducing a catalyst precursor which is prepared by intimately mixing a defined Feitnecht compound with a non-calcined alumino-silicate clay mineral and at the same time and/or subsequently but prior to calcination with at least one added stabilizing additive for reducing silicon-species loss selected from the group consisting of alkaline earth metal compounds, rare earth metal compounds and mixtures thereof, and, optionally, an alkali metal compound, and thereafter calcining the intimate mixture, wherein the catalyst has been found to be suitable for the steam reforming of methane at the working temperature of the molten carbonate fuel cell and has been found to be substantially resistant to deactivation in the hot alkali metal carbonate environment.

Abstract: A method for guiding a motor driven wheeled device in a required direction along the interior of a pipe comprises providing the device with a guard, lowering the device with the guard leading through a hole bored in the wall of the pipe to gain access to the interior of the pipe, causing the guard to engage the internal wall of the pipe and position the device on its wheels facing in the required direction and then starting the motor to cause the wheels to rotate and move the device in the required direction.

Abstract: Air is passed under pressure into a pipe under test and into a reference chamber connected to the pipe by a valve while recording at intervals of every few seconds the temperature in the reference chamber, the temperature in the pipe and the absolute pressure in the reference chamber. When the test pressure has been reached the valve is closed and the differential pressure between the pipe and the reference chamber is measured. The valve is opened to equalize the pressure and then closed again and the differential pressure drift rate is measured. This is repeated several times. A computer is used to calculate a creep prediction curve. A comparison is made to see whether the pressure drift rate due to creep and leak only in the pipe independent of any temperature change in the pipe is trending towards crossing the curve or not.

Abstract: A fuel cell is operated at a temperature which is not greater than substantially 250.degree. C., has an electrolyte which can be a solid polymer electrolyte, a liquid phosphoric acid electrolyte, or a liquid alkaline electrolyte, and a cathode and an anode each comprising a platinum catalyst. Hydrogen fuel gas is supplied to the anode and a gaseous oxidant, for example oxygen is supplied to the cathode. The cathode and anode are both connected to first and second circuits in parallel. The first circuit includes a load to be powered by the fuel cell and a first switch. The second circuit includes a battery and a second switch. The switches are operated by a control. When the first swtich is closed the cell powers the load and the second switch is open. When the first switch is open the second switch is closed so the battery applies a reverse D.C. potential the anode and cathode.

Abstract: A boiler control system includes a room temperature sensor 10 which utilises radio transmission to send temperature information via antenna 11 to receiver 15 via antenna 16. The receiver will provide an output to a control unit 18 to cause actuation of the boiler 19 for example if the room temperature falls below a preset value. The temperature selected can be varied by means of up/down keys 13/14 on the sensor 10. Temperature information can be displayed by means of display 12. Unique coding identifies the transmitting sensor and transmission can be sequenced on a number of frequencies to reduce the risk of reception failure. Additional temperature sensors including a hand held unit each with a unique identity code can be used and transmission time is varied to avoid coincident transmission from the sensors. Telephone linkage for a number of devices can be provided.

Abstract: Apparatus is provided for detecting faults in a sensor providing an output voltage representative of aeration of a combustible mixture. The apparatus comprises a control box which checks whether the value of a reference voltage with which the output voltage is compared to control the aeration is suitable for causing an intended value of the aeration to be maintained.

Abstract: The apparatus comprises a frame having a die pivotally connected to it at one end and anchorage means pivotally connected to it at the other end. The anchorage means carries a first roller. A second roller is adjustable transverse to the frame. A pipe pusher is integral with the die. The frame has adjustable legs to set the angle of the fame. A plastic pipe is pulled through the die and through the host pipe and is bent between the first roller, the second roller and the die. The frame fully contains the reactions arising owing to the bending of the pipe.

Abstract: After having used a known locator and a known transmitter of an electromagnetic field to find the general line of an element such as a pipe 14, the transmitter is kept activated and a probe is used having a linear coil 32 on its tip 30 which lies with its axis parallel to the length of the tip. The probe includes a display and the probe is inserted in the ground and rocked to and fro to determine when the coil is in a minimum current condition. The probe is inserted further and the same procedure repeated. Eventually the probe contacts the pipe and lies in a radial plane with respect to the pipe.

Abstract: An electrical power generating arrangement (for example, in a combined heat and (CHP) system in is which fixed frequency AC electric power for supply to the mains or grid is output from a frequency converter supplied with a variable frequency AC power input from an electrical generator driven by an internal combustion engine. The speed of the engine is varied by operation of a throttle controlled by a controller containing a predetermined engine map representing variation of engine speed as a function of the variation in electrical power output from the frequency converter to meet the demand of an external electrical load. On the load demand changing, the controller signals the frequency converter to give a changed new power output to meet the changed demand. The controller consults the map to determine the new engine speed corresponding to the new power demand and operates the throttle to cause the engine to run at the new speed.

Abstract: A method is provided for replacing an existing service pipe carrying fluid to an outlet within a property with a replacement service pipe. In the method the outlet is disconnected within the property from the existing service pipe in such a way that both during and after disconnection fluid is prevented from escaping into the property. A desired length of replacement service pipe is then fed into the existing service pipe in such a way that during and after the feeding step fluid is prevented from escaping into the property. The outlet is then connected to the outlet end of the replacement pipe in such a way that during the connection fluid is prevented from escaping into the property and after the connection step fluid is allowed to pass to the outlet solely by way of the replacement pipe.

Abstract: A fuel gas-fired premixed burner includes a flame strip having a plurality of through slots. Each slot includes a relatively narrow dimension portion that opens stepwise by means of a land into an outlet portion of a substantially constant relatively wide dimension. Under given conditions the burner flame stabilizes either at the outer end of the outlet portion (at a relatively high heat input range) or on the lands (at a relatively low heat input range) accompanied by reduction of the resonance tendency of the burner over those heat input ranges.

Abstract: An electrical power generating arrangement (for example, in a combined heat and power system) in which electric power for supply to mains or grid is output from a generator driven via a continuously variable transmission (C.V.T.) by an internal combustion engine having a throttle. The throttle opening and ratio of the C.V.T. are controlled by a controller comprising a computer programmed with an engine map which is consulted by the computer when there is a change in an external electrical load power demand. For any load, the map indicates at which speed the engine should be run for optimum engine efficiency, the throttle opening is varied to attain that speed, and the controller varies the ratio of the C.V.T. to a value consistent with the desired engine speed.

Abstract: A gas sensor for use in monitoring gases such as H.sub.2 S, NO.sub.2 or SO.sub.2 comprises a film or layer of non-protonated polyaniline as the gas sensing material.

Abstract: A fuel fired burner comprises a chamber for receiving a premixture of fuel and air. A wall of the chamber is in the form of a flamestrip provided with a plurality of elongate slots extending through the wall. Each slot has an inlet portion which converges to an end leading to a substantially constant dimension portion. The pitch of the slots along the chamber wall is P, the width of each slot is w, and the length of the constant dimension portion is L. The dimensions of the flamestrip are arranged such that L/w.gtoreq.10 and P/w.gtoreq.2. A burner including such an arrangement reduces the likelihood of resonant combustion noise being generated when enclosed within a heating appliance.

Abstract: An optical sensor assembly includes a light source, a surface plasmon-sensitive structure for reflecting light, a light detector, and a signal indicator. The light detector receives light that is reflected from the surface plasmon-sensitive structure at an angle which is sensitive to surface plasmon absorption.

Abstract: A method of converting a reactant gas mixture of CO.sub.2, O.sub.2 and CH.sub.4 comprises contacting the reactant gas at 750.degree.-850.degree. C. with a solid catalyst, which is a d-block transition metal or oxide such as a group VIII metal on a metal oxide support such as alumina, and which selectively converts the reactant gas into a product gas mixture comprising H.sub.2 and CO.

Abstract: Apparatus is provided for introducing sealant into a clearance between a replacement pipe 9 and an existing pipe 36 within which in use the replacement pipe 9 is located. The apparatus comprises a nose-cone 1 having a tubular body 6 for connection to the upstream end 8 of the replacement pipe 9, frangible means 20 in the form of a pop-out plug; pierceable metal foil; plastic film or membrane to seal the bore of the tubular body 6 and at least one non return valve 2 in the form of an elastic ring 2, rubber O-ring 40 or plug 52 and spring assembly 53 to permit the flow of sealant from the bore of the body 6 into the clearance 37 by way of the wall of the body 6 but to resist return-flow from the clearance 37 into the bore.