Methods and devices for producing high purity steam

A method of controlling a flow of purified steam in a steam generator having a heater for heating fluid in a vessel, comprising:

• delivering steam from the steam generator to a first side of a filtering membrane;
• receiving purified steam from a second side of the filtering membrane, the purified steam having a steam flow rate;
• determining, at a particular set of environmental conditions, coefficients of a substantially linear mathematical relationship between the steam flow rate of the purified steam and duty cycle applied to the heater;
• repeating the determining at different sets of operating conditions, whereby each set of operating conditions is associated with particular coefficients of a substantially linear mathematical relationship between the steam flow rate of the purified steam and duty cycle applied to the heater for the corresponding particular set of coefficients;
• configuring the steam generator to:
• select, based on existing operating conditions, the coefficients associated with one of the different set of operating conditions that optimally matches the existing operating conditions;
• and
• control:
• the duty cycle of the heater based on the determined at least one coefficient and a target steam flow rate of purified steam;
• and/or
• the target steam flow rate of purified steam based on the at least one coefficient and a target duty cycle of the heater.

A method for controlling a flow of purified steam in a steam generator having a heater for heating fluid in a vessel, comprising:

• delivering the steam from the steam generator to a first side of a filtering membrane;
• receiving purified steam from a second side of the filtering membrane, the purified steam having a steam flow rate;
• storing, on a memory associated with the steam generator, relationship parameters between the steam flow rate and a duty cycle of the heater;
• receiving a target steam flow rate or a target duty cycle for the heater;
• and
• adjusting the duty cycle of the heater based on the relationship and the received target steam flow rate;
• wherein the relationship parameters include coefficients of a linear equation for changes in the duty cycle relative to the steam flow rate.