| CELERITY, INC Patent applications |
| Patent application number | Title | Published |
| 20100049461 | MASS FLOW CONTROLLER WITH IMPROVED DYNAMIC - A system and method of compensating for pressure variations in a flow controller entails the use of the compressibility of the gas being controlled to provide a more accurate measurement of the flow. | 02-25-2010 |
| 20100005876 | THERMAL FLOW METER - A thermal mass flow controller or mass flow meter having a novel sensor housing that reduces heat conduction from the housing mounting plate or base to the sensor itself. The housing also greatly minimizes the thermal gradient that can result from the uneven application of heat to the housing base. This reduction is accomplished in part by the use of one or more thermal isolation slots to isolate the upper portion of the housing (which holds the sensor) from the lower portion of the housing. Heat transfer to the sensor housing is also minimized by raising the middle portion of the bottom of the housing so that thermal contact is made between the base and the housing only at the two ends of the housing. | 01-14-2010 |
| 20090281671 | FLOW MEASUREMENT AND CONTROL WITH BUBBLE DETECTION - Systems and methods for liquid flow sensing and control for use with a variety of different types of liquid flow measurement and control systems. The liquid flow sensor system senses a flow signal indicative of the flow rate of the liquid flowing in a sensor conduit and analyzes the flow signal to determine, by detecting characteristic changes in the signal, whether a bubble is present in the sensor conduit. Where the system determines that a bubble is present, it may generate an alarm signal indicative of the presence of the bubble. A flow control system incorporating the flow sensor as a feedback source may respond to the detection of a bubble by temporarily freezing the flow control parameters until the bubble has exited the sensor conduit. The flow control system can implement procedures for clearing a bubble from the sensor conduit where the system detects that the bubble has become stuck. | 11-12-2009 |
| 20090095068 | SYSTEM FOR AND METHOD OF PROVIDING A WIDE-RANGE FLOW CONTROLLER - An improved flow measuring device, such as a mass flow meter or mass flow controller, providing a high turn-down ratio as compared to prior art devices. In accordance with various embodiments of the invention, a flow sensor includes a sensor flow path that includes one or more restrictions configured to provide the sensor flow path with a non-linear relationship between a pressure drop across the sensor flow path and the flow of fluid through the flow sensor conduit. Such a flow sensor preferably achieves a high turn-down ratio by way of a variable bypass ratio that is directly proportional to the sensor tube mass flow rate so that the turn-down ratio of the mass flow controller will be ideally proportional to the square of the turndown achievable by the flow sensor conduit fluid sensing portion alone. In some embodiments, the restriction can be employed as a part of a fluid seal having an orifice and disposed between a flow sensor portion of a flow meter and a bypass portion of the flow meter. | 04-16-2009 |
| 20090078055 | METHODS AND APPARATUS FOR PRESSURE COMPENSATION IN A MASS FLOW CONTROLLER - Performance of mass flow controller may be vulnerable to pressure transients in a flow path to which the controller is coupled for the purpose of controlling the fluid flow. A system and method are provided for reducing or eliminate performance degradations, instabilities, and/or inaccuracies of a mass flow controller caused by changes in the pressure environment. In particular, a method and system are provided for compensating for pressure transients in the pressure environment of a flow path and mass flow controller. | 03-26-2009 |