Process and system for automated online fouling prevention of vertical shell and tube gas-to-gas heat exchangers
AssigneeOMNI Conversion Technologies Inc.
InventorsXiaoping Zou, Thomas Edward Wagler, Marc Bacon, Andreas Tsangaris, Shadi Saberi, Douglas Michael Feasby, Jonathan Enns, Scott Reid
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Abstract
A process and system for automated online fouling prevention of vertical shell and tube gas-to-gas heat exchangers is provided. The process and system of the invention utilize the flow velocity of the gas within the tubes to facilitate cleaning of the tubes by adding, when necessary, grit to the contaminated gas flow.
Claims18
A process for on-line prevention of fouling of a gas-to-gas heat exchanger wherein the gas-to-gas heat exchanger is a shell and tube gas-to-gas heat exchanger having a tube side and shell side, contaminated gas flows through the tube side and clean gas through the shell side, the process comprising:
- a) measuring gas temperatures, composition and flowrates;
- b) calculating a heat exchange coefficient from measured temperatures, composition and flowrates of gases in the gas-to-gas heat exchanger to obtain a measured heat exchange coefficient;
- c) comparing the measured heat exchange coefficient to a predetermined heat exchange coefficient;
- and
- d) if measured heat exchange coefficient is less than the predetermined heat exchange coefficient, add grit to the contaminated gas;
- wherein the contaminated gas has a flow velocity in the tubes sufficient for abrasive cleaning.
A system for on-line prevention of fouling of a gas-to-gas heat exchanger wherein the gas-to-gas heat exchanger is a shell and tube gas-to-gas heat exchanger having a tube side and shell side, contaminated gas flows through the tube side and clean gas through the shell side, the system comprising:
- a grit injection apparatus, and;
- a control system configured to:
- receive temperature measurements of the contaminated gas and the clean gas,
- receive composition measurements of the contaminated gas and the clean gas,
- receive flowrate measurements of the contaminated gas and the clean gas,
- calculate a heat exchange coefficient from measured temperatures, composition and flowrates of gases in the gas-to-gas heat exchanger to obtain a measured heat exchange coefficient;
- comparing the measured heat exchange coefficient to a predetermined heat exchange coefficient;
- and
- if measured heat exchange coefficient is less than the predetermined heat exchange coefficient, signal the grit injection apparatus to add grit to the contaminated gas;
- wherein the temperatures are measured by a plurality of thermocouples.
A heat exchange system comprising:
- a shell and tube gas-to-gas heat exchanger having a tube side and shell side, wherein hot contaminated gas flows through the tube side and clean gas through the shell side;
- at least one grit injection apparatus, each grit injection apparatus comprising a distribution and pressure charging hopper operatively connected to a main hopper and a mechanical pressurization means or pressurizing gas line;
- at least one vertical pipe extending from the distribution and pressure charging hopper;
- wherein the distribution and pressure charging hopper and the at least one vertical pipe are configured to be pressurized;
- a grit outlet pipe operatively connected to the at least one vertical pipe and extending into an upper plenum of the shell and tube gas-to-gas heat exchanger;
- wherein the grit injection apparatus is configured to provide pressurized grit to the upper plenum;
- and
- a control system configured to:
- receive temperature measurements of the contaminated gas and the clean gas,
- receive composition measurements of the contaminated gas and the clean gas,
- receive flowrate measurements of the contaminated gas and the clean gas,
- calculate a heat exchange coefficient from measured temperatures, composition and flowrates of gases in the shell and tube gas-to-gas heat exchanger to obtain a measured heat exchange coefficient;
- comparing the measured heat exchange coefficient to a predetermined heat exchange coefficient;
- and
- if measured heat exchange coefficient is less than the predetermined heat exchange coefficient, signal the grit injection apparatus to add grit to the contaminated gas.
Dependencies are inferred from the claim text.