Removable flue gas strainer and associated methods

A flue gas strainer apparatus to filter heated flue gas flowing from a heating element to a fluid catalytic cracking unit, the flue gas strainer apparatus comprising:

• a housing positioned in a flowpath of a heated flue gas stream between a heating element and a fluid catalytic cracking unit, the housing having a front end and a back end, the housing comprising two or more receiving portions, an outer edge, an inner edge, and an inner bore extending from the front end to the back end of the housing along the inner edge, the inner bore positioned to allow the heated flue gas stream to pass therethrough, and the outer edge configured to sealingly engage a duct, thereby to prevent portions of the heated flue gas from escaping the housing and the duct when flowing through the inner bore;
• two or more moveable strainer portions each comprising a mesh portion having a plurality of pores and configured to capture solid particulates suspended in the heated flue gas stream when flowing through the inner bore, the mesh portion operable to be removingly received in a corresponding one of the two or more receiving portions of the housing such that:
• in a first configuration, the mesh portion resides within the inner bore of the housing and captures solid particulates suspended in the heated flue gas stream passing therethrough, and
• in a second configuration, the mesh portion resides external to the housing;
• a first sensor positioned downstream of the two or more moveable strainer portions and configured to measure a first characteristic;
• a second sensor positioned upstream of the two or more moveable strainer portions and configured to measure a second characteristic;
• and
• a controller in signal communication with the first sensor and the second sensor, the controller configured to:
• obtain the first characteristic and the second characteristic, and
• based on the first characteristic and the second characteristic, move one or more of the two or more moveable strainer portions from one of (a) the first configuration to the second configuration or (b) the second configuration to the first configuration.

A system to filter heated flue gas flowing from a heating element to a fluid catalytic cracking unit, the system comprising:

• two or more flue gas apparatuses engaged with a duct in series, each of the two or more flue gas apparatuses comprising:
• a housing positioned in a flowpath of a heated flue gas stream between a heating element and a fluid catalytic cracking unit, the housing having a front end and a back end, the housing comprising a receiving portion, an outer edge, an inner edge, and an inner bore extending from the front end to the back end of the housing along the inner edge, the inner bore positioned to allow the heated flue gas stream to pass therethrough;
• a moveable strainer portion comprising one or more mesh portions having a plurality of pores and configured to capture solid particulates suspended in the heated flue gas stream, the one or more mesh portions operable to be removingly received in the receiving portion of the housing such that:
• in a first configuration, one or more of the one or more mesh portions reside within the inner bore of the housing and captures solid particulates suspended in the heated flue gas stream passing therethrough, and
• in a second configuration, one or more of the one or more mesh portions reside external to the housing;
• a first pressure sensor positioned downstream of the moveable strainer portion and configured to measure a downstream pressure of the heated flue gas stream when flowing through the inner bore;
• a second pressure sensor positioned upstream of the moveable strainer portion and configured to measure an upstream pressure of the heated flue gas stream when flowing through the inner bore;
• an optical sensor connected to the housing and operable to optically inspect and monitor fouling of the one or more mesh portions;
• and
• a controller in signal communication with the first pressure sensor, the second pressure sensor, and the optical sensor of each of the two or more flue gas apparatuses, the controller configured to:
• obtain the downstream pressure and the upstream pressure for each of the two or more flue gas apparatuses,
• determine a pressure differential for each of the two or more flue gas apparatuses based on a respective downstream pressure and a respective upstream pressure,
• determine whether the one or more mesh portions of each of the two or more flue gas apparatus exceed a fouling threshold, and
• for each of the two or more flue gas apparatuses, based on the respective differential pressure and whether the one or more mesh portions of each of the two or more flue gas apparatus exceeds the fouling threshold, move one or more of the one or more mesh portions from one of (a) the first configuration to the second configuration or (b) the second configuration to the first configuration.