Abstract: A shunt-enhanced compression and pulsation trap (SECAPT) for a screw compressor assists internal compression (IC), reduces gas pulsation and NVH, and improves off-design efficiency, without using a slide valve and/or a serial pulsation dampener. The SECAPT includes an inner casing (e.g., an integral part of the compressor chamber) and an outer casing (e.g., surrounding part of the inner casing near the compressor discharge port) forming at least one diffusing chamber with a nozzle and a feedback region that provides a feedback flow loop between the compressor chamber and the compressor discharge port. The SECAPT automatically compensates cavity pressure to meet different outlet pressures (hence eliminating under-compression and/or over-compression when the discharge port opens), partially recovers potential energy associated with the under-compression (UC), and traps and attenuates gas pulsations and noise before the discharge port opens.

Abstract: Integrated rotary positive-displacement machinery, for example compressors and/or vacuum pumps, include a compressor core equipped with at least one shunt pulsation trap and at least one absorptive silencer integrated together along with other compressor components (such as inlet/outlet pulsation dampeners, gas filters, safety valves, etc.) into a unit or package with a reduced pulsation, noise, energy consumption, and size and weight. Some embodiments further include at least one 4-way valve and corresponding piping so that the same positive-displacement machine can be operated to selectively provide vacuum and pressure by operation of the valve and piping.

Abstract: A shunt pulsation trap for a positive-displacement gas-transfer machine having a gas transfer chamber with an intake port and a discharge port and having at least one positive-displacement drive device (such as two cooperating rotors) defining a compression region of the transfer chamber. The trap includes a pulsation-trap chamber arranged for parallel fluid flow with the machine transfer chamber. The trap has a first (e.g., inlet) port in communication with the compression region of the transfer chamber (e.g., at least one lobe span away or totally isolated from the transfer-chamber intake port), a second (e.g., discharge) port in communication with the discharge port of the transfer chamber, and at least one pulsation dampener in the pulsation-trap chamber. In this way, the shunt pulsation trap traps and attenuates gas pulsations before discharge from the machinery transfer chamber, thereby reducing induced NVH and improving machinery efficiency.

Abstract: A shunt pulsation trap for a positive-displacement gas-transfer machine having a gas transfer chamber with an intake port and a discharge port and having at least one positive-displacement drive device (such as two cooperating rotors) defining a compression region of the transfer chamber. The trap includes a pulsation-trap chamber arranged for parallel fluid flow with the machine transfer chamber. The trap has a first (e.g., inlet) port in communication with the compression region of the transfer chamber (e.g., at least one lobe span away or totally isolated from the transfer-chamber intake port), a second (e.g., discharge) port in communication with the discharge port of the transfer chamber, and at least one pulsation dampener in the pulsation-trap chamber. In this way, the shunt pulsation trap traps and attenuates gas pulsations before discharge from the machinery transfer chamber, thereby reducing induced NVH and improving machinery efficiency.

Abstract: A shunt pulsation trap for a screw compressor reduces gas pulsation and NVH, and improves off-design efficiency, without using a traditional serial pulsation dampener and a sliding valve. A screw compressor has a pair of multi-helical-lobe rotors that are housed in a compressor chamber that propel gas flow from a suction port to a discharge port of the compressor chamber. The shunt pulsation trap includes an inner casing as an integral part of the compressor chamber, and an outer casing oversized and surrounding the inner casing. The shunt pulsation trap houses at least one gas pulsation dampening device, and includes at least one injection port (trap inlet) branching off from the compressor chamber into the pulsation trap chamber and a feedback region (trap outlet) communicating with the compressor outlet.

Abstract: A shunt pulsation trap for a rotary lobe blower (pump) or vacuum pump reduces pulsation and NVH, and improves efficiency, without increasing overall size of the blower or pump. A rotary lobe blower (pump) or vacuum pump has a pair of synchronized parallel multi-lobe rotors that are housed in a transfer chamber and that propel flow from a suction port to a discharge port of the transfer chamber. The shunt pulsation trap includes an inner casing as an integral part of the transfer chamber, and an outer casing oversized and surrounding the inner casing. The shunt pulsation trap houses at least one various pulsation dampening device, and includes at least one injection port (trap inlet) branching off from the transfer chamber into the pulsation trap chamber and at least one feedback port (trap outlet) communicating with the blower outlet pressure.

Abstract: A shunt pulsation trap for a cyclic positive displacement (PD) compressor reduces gas pulsation and NVH, and improves off-design efficiency, without using a traditional serial pulsation dampener and a variable geometry. A shunt pulsation trap for a cyclic PD compressor is configured to trap and attenuate gas pulsations before discharge and includes a housing having a flow suction port, a flow discharge port, a compressor cavity, and a pulsation trap chamber adjacent to the PD compressor cavity. The pulsation trap chamber includes at least one pulsation dampening device, at least one injection port (trap inlet) branching off from the PD compressor cavity into the pulsation trap chamber and a feedback region (trap outlet) communicating with the PD compressor outlet. The associated methods of reducing pulsations are included as another aspect of the invention.

Abstract: A high pressure centrifugal blower having vertically split casing and aluminum or steel impellers mounted on a common shaft housed within the casing, and at least two oil-enclosing bearing housings to rotatably support the rotors, where an integral gearbox is formed as part of the blower casing so as to increase the impeller rotational speed to achieve higher pressure, and axial impeller eye seals are utilized to reduce the clearance and enhance reliability for higher pressure applications.

Abstract: A rotary blower with forced external air cooling having multiple interconnected and synchronized parallel multi-lobe rotors with the same number of straight lobes for propelling flow from a suction port to a discharge port of an inner casing without internal compression. The blower also has an outer cover with cooling air inlet and outlet openings and added centrifugal cooling fans mounted on the rotor shafts adjacent to the cooling air inlet openings for circulating cooling air through the space between the outer cover and the inner casing. The blower further utilizes wearable strip seal devices applied on the rotors for preventing internal leakage and accidental mechanical contact.