Steam generation apparatus and method

A steam generation apparatus for connection to a steam injection boiler including a water tube circuit extending through the steam injection boiler and selected to convey water in order that the water is heated to generate steam, the steam generation apparatus comprising:

• a first step-up heater connectable in fluid communication with the boiler water tube circuit;
• and
• a second step-up heater in fluid connectable communication with the boiler water tube circuit,
• the first and second step-up heaters being operable at conditions to treat the water in association with the boiler to a level wherein fouling of water solids occurs in the first step-up heater and the second step-up heater preferentially over fouling occurring in the boiler and the first and second step-up heaters being connected in parallel such that one step-up heater can be operated while the other step-up heater is offline.

A steam generation apparatus comprising:

• a steam injection boiler including a burner operable therein and a boiler water coil extending through the steam injection boiler and including an outlet the boiler water coil selected to convey water in order to heat the water to generate steam;
• at least a first heater and a second heater, each including a steam heating circuit, the steam heating circuits being connected in parallel with each other and in fluid flow communication with the boiler water coil and the heater selected to increase the steam quality of the steam passing from the steam injection boiler;
• and
• a flow controller to control flow through the first and the second heaters and actuable to select that flow is permitted through only a selected one of the first heater steam heating circuit and the second heater steam heating circuit.

A method for generating steam, the method comprising:

• providing a steam generation apparatus including a fired steam injection boiler including a combustion chamber and a water tube extending through the steam injection boiler combustion chamber;
• providing a step-up heater in series after the steam injection boiler including a steam/water tube extending therethrough;
• operating the steam injection boiler to convey water through the water tube to heat the water to generate steam;
• operating the step-up heater to receive steam generated in the steam injection boiler and passing it through the steam/water tube at conditions to heat the steam from the boiler to a level wherein fouling of water solids occurs in the step-up heater preferentially over fouling occurring in the steam injection boiler.

A method for generating steam, the method comprising:

• providing a steam generation apparatus including a fired steam injection boiler including a combustion chamber and a water tube extending through the steam injection boiler combustion chamber;
• providing a first step-up heater and a second step-up heater;
• operating the boiler to convey water through the water tube to heat the water to generate steam;
• operating at least the first step-up heater at conditions to heat the water in association with the boiler to a level wherein fouling of water solids occurs in the first step-up heater preferentially over fouling occurring in the steam injection boiler;
• shutting down the first step-up heater to defoul it;
• and
• operating the second step-up heater to heat the water in association with the boiler while the first step-up heater is shut down.

A method for generating steam comprising:

• using a steam injection boiler including a burner operable therein and a boiler water coil extending through the steam injection boiler and including an outlet of the boiler water coil, the steam injection boiler selected to convey water in order to heat the water to generate steam;
• at least a first heater and a second heater, each including a steam heating circuit, the steam heating circuits being connected in parallel with each other and in fluid flow communication with the boiler water coil and selected to increase the steam quality of the steam passing from the steam injection boiler;
• and a flow controller to control flow through the first and the second heaters;
• conveying water through the boiler water coil and through the steam heating circuit of a selected one of the first heater or the second heater to generate steam from the water;
• defouling the steam heating circuit of the other of the first heater or the second heater;
• and
• switching flow to the other of the first heater or the second heater when the steam heating circuit of the selected heater when it is desired to defoul the steam heating circuit of the selected one of the first heater or the second heater.