A filter capsule apparatus comprising: a capsule shell having portions defining a shell wall (12"') with additional portions defining a solid, channel-free capsule shell bottom end connected to a bottom end of the shell wall (12"'); a top cap secured to a top end of the shell wall (12"'), wherein the combination of the shell wall (12"'), the capsule shell bottom end and the top cap define a filter chamber having a filter chamber top end proximal to and partially defined by the top cap and a filter chamber bottom end proximal to and partially defined by the capsule shell bottom end; a filter (34"') secured in the filter chamber, wherein an annular space is defined by the shell wall (12"') and an exterior surface of the filter (34"'), wherein the annular space extends uninterrupted the entire axial length of the filter (34"'), wherein a bottom space is defined by a bottom end of the filter (34"'), an inner surface of the capsule shell bottom end and an annular segment of the shell wall (12"') below the plane occupied by the bottom end of the filter (34"'), wherein the bottom space is in uninterrupted fluid communication with the annular space, and wherein heated fluid is permitted to enter the filter (34"') radially inwardly along the axial length of the filter (34"') from the annular space; a plurality of ports (24, 26, 28) including an inlet port extending from the top cap, a transfer tube (40"') having an elongate tube cylindrical wall connected in fluid isolation from the annular space and the filter (34"'), connected along its length to, and extending along the length of, the shell wall (12"'), wherein a portion of the tube wall along its axial length is integral with, or registered against, the shell wall (12"'), wherein a fluid receiving first end is secured to, and in fluid communication with, the inlet port and a fluid delivery second end is secured in close proximity to the capsule shell bottom end; characterized by a dispersion ring formed on, or secured to, a peripheral annular edge of the inner surface of the capsule shell bottom end within the filter chamber, wherein the dispersion ring has a plurality of dispersion ring bores or slots, wherein the dispersion ring is in fluid communication with the second end of the transfer tube (40"'), and wherein the dispersion ring is in fluid communication with the filter chamber via the plurality of ring bores or slots, whereby higher-heat, lower-density heated fluid introduced into the filter capsule (10"') enters through the inlet port, travels downwardly inside the transfer tube (40"'), exits the transfer tube second end into the dispersion ring, exits the dispersion ring through the ring bores or slots into the uninterrupted bottom space of the filter chamber, and flows upwardly in the uninterrupted annular space of the filter chamber into the filter (34"'), whereby the heated fluid transfers heat to lower-heat, higher-density fluid positioned at a higher elevation in the filter chamber than the in-flowing heated fluid in a fluid column formed in the filter chamber to maintain all the fluid in the fluid column at a substantially uniform temperature throughout the axial length of the filter chamber. a capsule shell having portions defining a shell wall (12"') with additional portions defining a solid, channel-free capsule shell bottom end connected to a bottom end of the shell wall (12"'); a top cap secured to a top end of the shell wall (12"'), wherein the combination of the shell wall (12"'), the capsule shell bottom end and the top cap define a filter chamber having a filter chamber top end proximal to and partially defined by the top cap and a filter chamber bottom end proximal to and partially defined by the capsule shell bottom end; a filter (34"') secured in the filter chamber, wherein an annular space is defined by the shell wall (12"') and an exterior surface of the filter (34"'), wherein the annular space extends uninterrupted the entire axial length of the filter (34"'), wherein a bottom space is defined by a bottom end of the filter (34"'), an inner surface of the capsule shell bottom end and an annular segment of the shell wall (12"') below the plane occupied by the bottom end of the filter (34"'), wherein the bottom space is in uninterrupted fluid communication with the annular space, and wherein heated fluid is permitted to enter the filter (34"') radially inwardly along the axial length of the filter (34"') from the annular space; a plurality of ports (24, 26, 28) including an inlet port extending from the top cap, a transfer tube (40"') having an elongate tube cylindrical wall connected in fluid isolation from the annular space and the filter (34"'), connected along its length to, and extending along the length of, the shell wall (12"'), wherein a portion of the tube wall along its axial length is integral with, or registered against, the shell wall (12"'), wherein a fluid receiving first end is secured to, and in fluid communication with, the inlet port and a fluid delivery second end is secured in close proximity to the capsule shell bottom end;