Abstract: Systems and methods are disclosed for the automatic control of one or more pumping and compressing machines and of the related fluid network. The purpose of such systems and methods is to maintain only the required pressure just after a source or just before a user so as to reduce the compressing or pumping energy required; to divide the load within a group of one or more compressing or pumping machines so as to compress the fluid with reduced use of energy and improved pressure control; to improve protection of the turbo compressors when used in parallel from dangerous levels of operation.

Abstract: A control system is disclosed for a noninteracting control and protection of a dynamic compressor having rotating vanes.The method consists of a junction of a few control circuits for controlling the performance of a dynamic compressor, for protecting compressor from approaching dangerous zones of operation, and for maintaining a required mass flow rate of a gas through the compressor.An automatic control system based on using the above method is distinguished by its simplicity, great transient and steady state precision and high reliability of surge protection.

Abstract: A method is disclosed for a cascade control of a dynamic compressor to maintain a constant mass flow rate to a process. The method consists of a successive junction of control loops for controlling the speed of rotation, the pressure in the delivery, and the mass flow rate; the output signal of each outer loop being the input signal for the inner loop and each of the loops containing a compensating element to reduce the effects of large time constants of all previous loops.An automatic control system based on using the above method, distinguished by its great static and dynamic precision in maintaining a controlled parameter, and by the high reliability of protection of the compressor from surge, and protection from a dangerous increase of the speed of rotation and of a dangerous increase of the discharge pressure.

Abstract: A control system is disclosed for a cascade control of a dynamic compressor having a variable speed of rotation to maintain a constant pressure to a process. The method consists of a successive junction of control loops for controlling the speed of rotation, the flow rate of a compressor, the pressure in the delivery or in suction; the output signal of each outer loop being the input signal for the inner loop and each of the loops containing a compensating element to reduce the effects of large time constants of all inner loops.An automatic control system based on using the above method, distinguished by its great transient and steady state precision in maintaining a main controlled parameter, and by the high reliability of protection of the compressor from surge and from a dangerous increase of the speed of rotation.

Abstract: A method is disclosed for the improved operation of heating stoves for blast furnaces. This method is comprised of a combined use of an independent source of compressed air and potential and thermal energy of air remaining in the heating stoves at the end of a period of cooling. The purpose of this method is to reduce the time of filling of the ready to go on -- wind stoves by compressed air; to stabilize the operating conditions of the blast furnace; to save coke; to save the fuel spent on heating the stoves.

Abstract: A method and apparatus for protecting a dynamic compressor from surge. The method includes a first step for providing a simultaneous control of a smaller relief means and a main control member of a dynamic compressor or the driver thereof for changing the performance of the compressor. This combined action provides for the protection from surge and at the same time insures the invariability of the main control parameters of pressure, mass flow rate to the user, or the speed of rotation. The second step provides for controlling a larger relief means and provides for antisurge protection in those cases when the first step is not sufficient to protect the compressor from surge. Apparatus is also provided for automatically implementing the method.