초록 ▼

A direct contact steam injection heater includes a Mach diffuser having a plurality of steam diffusion holes in lieu of a coaxial steam nozzle. High velocity steam (i.e. choked flow) flows radially through the plurality of steam diffusion holes into a high velocity axial flow of liquid through a com

A direct contact steam injection heater includes a Mach diffuser having a plurality of steam diffusion holes in lieu of a coaxial steam nozzle. High velocity steam (i.e. choked flow) flows radially through the plurality of steam diffusion holes into a high velocity axial flow of liquid through a combining tube within the heater. An adjustably positionable cover over the steam diffusion holes in the Mach diffuser modulates the amount of steam added to the liquid by exposing the proper number of steam diffusion holes. This modulation is done at constant steam pressure without the use of an external steam control device. The arrangement facilitates thorough mixing of steam and liquid within the combining region. It also discourages the generation of relatively large steam bubbles within the mixture, even when heating liquids that promote the generation of relatively large steam bubbles such as liquids without a significant number or nucleation points or without sufficient surface tension. Upon condensation of steam in the heater, relatively large steam bubbles tend to cause vibrations in the heater and adjacent plumbing. The invention substantially eliminates this source of vibrations.

대표청구항 ▼

[ We claim:] [1.] A direct contact steam injection heater comprising:a heater body having a steam inlet, a liquid inlet, a combining region and a heated liquid discharge outlet;the combining region having an inlet and an outlet located within the heater body in which steam and liquid are combined to

[ We claim:] [1.] A direct contact steam injection heater comprising:a heater body having a steam inlet, a liquid inlet, a combining region and a heated liquid discharge outlet;the combining region having an inlet and an outlet located within the heater body in which steam and liquid are combined to generate heated liquid;a Mach diffuser that receives the flow of steam into the heater body and discharges the steam into the liquid flowing through the combining region, wherein a coaxial channel is located between the Mach diffuser and an inlet portion of the combining region of the heater body and the Mach diffuser contains a plurality of steam diffusion holes through which the steam is discharged into the liquid flowing through the channel between the Mach diffuser and the inlet portion of the combining region; andan adjustably positionable cover over the steam diffusion holes contained in the Mach diffuser that is movable relative to the Mach diffuser to adjustably expose one or more of the steam diffusion holes in the Mach diffuser and modulate the amount of steam discharged through the Mach diffuser into the liquid flowing through the combining region;wherein:the steam pressure upstream of the Mach diffuser is sufficient to create sonic choked flow conditions through the exposed diffusion holes through which steam is discharged from the Mach diffuser into the flow of liquid flowing through the channel between the Mach diffuser and the inlet portion of the combining region;the coaxial channel has a flow area substantially less than a flow are of a downstream portion of the combining region in which the injected steam condenses; andliquid flows through the inlet portion and the downstream portion of the combining region in an axial direction and steam flows in generally radial directions as the steam flows through the one or more steam diffusion holes in the Mach diffuser into the axial liquid flow through the channel between the Mach diffuser and the combining region of the heater body.