A control process and apparatus provide feed forward control of stoichiometric proportions of hydrogen sulfide and ammonia to a thermal oxidizer and an ammonia scrubber, respectively. To account for unmeasured or uncalculated sulfur feed to the thermal oxidizer, a feed back measurement of sulfur dioxide and ammonia concentration is used to correct the flow rate of hydrogen sulfide to the thermal oxidizer and/or ammonia to the ammonia scrubber.

A control process and apparatus provide feed forward control of stoichiometric proportions of hydrogen sulfide and ammonia to a thermal oxidizer and an ammonia scrubber, respectively. To account for unmeasured or uncalculated sulfur feed to the thermal oxidizer, a feed back measurement of sulfur dioxide and ammonia concentration is used to correct the flow rate of hydrogen sulfide to the thermal oxidizer and/or ammonia to the ammonia scrubber.

Provided are an apparatus for and a method of processing a substrate. The substrate processing apparatus includes a substrate processing unit to process a substrate using a processing solution containing a mixture of first and second sources; a source supplying part to supply the first and second sources to the substrate processing unit; at least one analyzer to measure a concentration of the second source in the processing solution or a pH value of the processing solution and adjust a measurement reference value of the second source in the processing solution using a standard solution, in which the first and second sources are mixed to have a predetermined concentration or pH value; and a standard solution supplying part to prepare the standard solution using the first and second sources to be supplied from the source supplying part and to supply the standard solution to the at least one analyzer.

Implementations are described for maintaining helium/air mixture within a tube in an evacuated tube transportation system. A first implementation includes a set of helium tanks uniformly fitted along the tube length, where helium is injected with controlled valves that open or close to maintain the desired level of helium. An operations control center (OCC) receives helium concentration levels in the tube and instructs a controller in the tube to release helium into the tube when detected levels of helium is lower than the desired level of helium. Another implementation is described where a capsule traversing the tube may have a source of helium gas that can be released into the tube. A hybrid approach is also described where helium can be released from a source within the tube and from another source within the capsule.

Implementations are described for maintaining helium/air mixture within a tube in an evacuated tube transportation system. A first implementation includes a set of helium tanks uniformly fitted along the tube length, where helium is injected with controlled valves that open or close to maintain the desired level of helium. An operations control center (OCC) receives helium concentration levels in the tube and instructs a controller in the tube to release helium into the tube when detected levels of helium is lower than the desired level of helium. Another implementation is described where a capsule traversing the tube may have a source of helium gas that can be released into the tube. A hybrid approach is also described where helium can be released from a source within the tube and from another source within the capsule.

Systems, methods, and software program products for dispensing chemical solutions. A controller receives a signal from a pressure sensor indicative of a pressure of a diluent. The controller determines an expected flow rate of the diluent through an eductor based at least in part on the pressure of the diluent. The controller may further determine an expected concentration of a chemical product in the solution dispensed from a discharge port of the eductor. Based on the expected flow rated and concentration of the chemical product, the controller determines a duration of a dispense stage of a dispensing operation required to dispense a predetermined dose of the chemical product. The controller then causes the diluent to flow through the eductor for the determined duration of the dispense stage. A check valve on the output of the eductor prevents dissimilar chemicals from mixing and reduces a response time of the eductor.

Systems, methods, and software program products for dispensing chemical solutions. A controller receives a signal from a pressure sensor indicative of a pressure of a diluent. The controller determines an expected flow rate of the diluent through an eductor based at least in part on the pressure of the diluent. The controller may further determine an expected concentration of a chemical product in the solution dispensed from a discharge port of the eductor. Based on the expected flow rated and concentration of the chemical product, the controller determines a duration of a dispense stage of a dispensing operation required to dispense a predetermined dose of the chemical product. The controller then causes the diluent to flow through the eductor for the determined duration of the dispense stage. A check valve on the output of the eductor prevents dissimilar chemicals from mixing and reduces a response time of the eductor.

Systems, methods, and software program products for dispensing chemical solutions. A controller receives a signal from a pressure sensor indicative of a pressure of a diluent. The controller determines an expected flow rate of the diluent through an eductor based at least in part on the pressure of the diluent. The controller may further determine an expected concentration of a chemical product in the solution dispensed from a discharge port of the eductor. Based on the expected flow rated and concentration of the chemical product, the controller determines a duration of a dispense stage of a dispensing operation required to dispense a predetermined dose of the chemical product. The controller then causes the diluent to flow through the eductor for the determined duration of the dispense stage. A check valve on the output of the eductor prevents dissimilar chemicals from mixing and reduces a response time of the eductor.

Systems, methods, and software program products for dispensing chemical solutions. A controller receives a signal from a pressure sensor indicative of a pressure of a diluent. The controller determines an expected flow rate of the diluent through an eductor based at least in part on the pressure of the diluent. The controller may further determine an expected concentration of a chemical product in the solution dispensed from a discharge port of the eductor. Based on the expected flow rated and concentration of the chemical product, the controller determines a duration of a dispense stage of a dispensing operation required to dispense a predetermined dose of the chemical product. The controller then causes the diluent to flow through the eductor for the determined duration of the dispense stage. A check valve on the output of the eductor prevents dissimilar chemicals from mixing and reduces a response time of the eductor.

Implementations are described for maintaining helium/air mixture within a tube in an evacuated tube transportation system. A first implementation includes a set of helium tanks uniformly fitted along the tube length, where helium is injected with controlled valves that open or close to maintain the desired level of helium. An operations control center (OCC) receives helium concentration levels in the tube and instructs a controller in the tube to release helium into the tube when detected levels of helium is lower than the desired level of helium. Another implementation is described where a capsule traversing the tube may have a source of helium gas that can be released into the tube. A hybrid approach is also described where helium can be released from a source within the tube and from another source within the capsule.