摘要:
A method for permitting the joining together of two adjacent pipe lengths with adjacent ends curving with substantially the same sense, the method comprising rotating the end of one of the pipe lengths about its axis until it curves in substantially the opposite sense to the curve of the adjacent end of the other pipe length.
摘要:
A mutant of the mono-oxygenase cytochrome P-450.sub.cam in which the tyrosine residue at position 96 and/or the cysteine residue at positon 334 is replaced by the residue of any amino acid except phenylalanine.
摘要:
An in-pipe vehicle for carrying out at least one operation in a pipeline. The vehicle includes a train of modules interlinked by suspension units to allow serpentine movement through pipe bends. The vehicle train has its own internal power supply and drive mechanism in the modules. A detector module determines the presence of a service junction using magnetic field information. A manipulative module allows the vehicle to be temporarily wedged in the pipeline while providing rotational movement to facilitate the desired operation at the junction. This may include drilling and welding of a service pipe to the main using appropriate modules. A remote probe typically containing a magnetic field generator can be used to assist in service junction location by the vehicle.
摘要:
Apparatus provides an air/fuel mixture to a fully premixed burner and comprises means for providing fuel at a variable flow rate to the burner, means for supplying air at a variable flow rate to the fuel to form the mixture, means for sensing aeration of the fuel combustion products and control means for controlling the fuel flow rate in dependence upon a heat output demand and the air flow rate in dependence upon both the fuel flow rate and the sensed aeration in such a way that the air flow rate is sufficient to maintain the aeration at a predetermined value, the controller, in use, maintaining the fuel flow rate at one of a number of predetermined values and the air flow rate at a corresponding one of a number of differing predetermined values, each set of predetermined values being characterized by a constant value of the ratio between successive values.
摘要:
A method for permitting the joining together of two adjacent pipe lengths with adjacent ends curving with substantially the same sense, the method comprising rotating the end of one of the pipe lengths about its axis until it curves in substantially the opposite sense to the curve of the adjacent end of the other pipe length.
摘要:
A method and apparatus for testing a fluid conduit system for leaks. The apparatus is connected to an isolated section of a domestic fuel gas system which is suspected of leaking. The apparatus determines over recorded time periods the pressure drop in the system as a result of the actual gas leak and subsequently the pressure drop in the system as a result of an actual leak plus the leakage through an introduced artificial and calibrated orifice provided by the apparatus. The data is used in an equation for calculating the actual leakage rate from the system. This method avoids the need to repressurize the system between pressure drop measurements or having to know or assume the volume of the system being tested.
摘要:
A process for producing natural gas hydrate comprises three states (i), (ii), and (iii). State (i) comprises three pressure vessels (A1, A2, and A3), stage (ii) two pressure vessels (A4 and A5), and stage (iii) the pressure vessel (A6). The conditions of temperature and pressure in the pressure vessels are such that the gas hydrate is formed in the vessels. The formed hydrate is taken off through pipes (e1, e2, e3, e4, e5, and e6) from the pressure vessels to a manifold (34). Chilled water which is both the reactant water and coolant for the process is provided by cooling means (20) and supplied simultaneously to the lower part of each pressure vessel via pipe (22), manifold (32) and pipes (b1, b2, b4, b5, and b6). Natural gas from supply (26) is fed via pipe (30), manifold (32) and pipes (c1, c2, and c3) to nozzles in the lower part of each vessel (A1, A2, and A3) from which nozzles the gas bubbles upwards through the columns of water in vessels (A1, A2, and A3). Unreacted gas is fed from vessels (A1, A2, and A3) to similar nozzles in the vessels (A4 and A5) from which unreacted gas is fed to a nozzle in the vessel (A6) from which the unreacted gas is taken off through pipe (d6). The mean upward superficial velocity of the gas is substantially the same in all three stages.
摘要:
A replacement pipe is installed within an existing service pipe (1) by first advancing a sealing means (6,8) along the existing pipe to a position adjacent its junction with a main pipe (2), then deploying the sealing means to seal against the inner surface of the existing pipe) in the example shown, by pumping sealant (10) into the space between the seal body (6) and the pipe (1), and subsequently advancing the replacement pipe along the existing pipe. The space between the two pipes is then filled with sealant and finally the sealing means is opened, in the example shown by withdrawing a guide rod (5) and its collar (7) on which the sealing means was advanced into position.
摘要:
An energy meter for measuring parameters of fuel gas. The meter has a gas inlet and outlet and a central tube along which the gas flows from inlet to outlet. Ultra-sound transducers and a control form a system whereby the speed of ultra-sound signals traveling through the gas between the transducers is measured and used in the control to calculate the volume of gas which is passed through the meter. The ultra-sound signals pass through apertures in the walls of chambers containing the transducers. Another ultra-sound transducer in the chamber which is connected to the control acts as an emitter and receiver of ultra-sound signals reflected by reflectors. These signals travel through the fuel gas in the chamber and their attenuation is observed and measured by the control when they are received by the transducer. The measured attenuation is used to derive the calorific value and/or Wobbe index of the gas. The control uses the volume of gas and the calorific value and/or Wobbe index to derive the amount of energy in the gas.