A falling film evaporator (12) includes an evaporator vessel (26), a plurality of evaporator tubes (38) disposed in the in evaporator vessel (26) through which a volume of thermal energy transfer medium is flowed and a suction port (42) extending through the evaporator vessel (26) to remove vapor refrigerant from the evaporator vessel (26). A refrigerant distribution system (34) is located in the evaporator vessel (26) to distribute a flow of liquid refrigerant over the plurality of evaporator tubes (38). The refrigerant distribution system (34) is configured such that the refrigerant distribution system (34) has a first height at the suction port (42) and a second height greater than the first height at a longitudinal location (28) other than at the suction port (42).

Generally, management of refrigerant in an evaporator of an HVAC chiller is described. Methods, systems, and apparatuses to manage refrigerant in an evaporator can include one or combination of the following approaches: (1) by use of a refrigerant displacement array to physically prevent refrigerant from residing where the array is positioned (2) by control of the interstitial velocity of refrigerant flow within the volume of the shell of an evaporator; (3) by a phase biased distribution of the refrigerant mixture, so that a gaseous portion is uniformly distributed into the evaporator shell, while liquid refrigerant and oil is distributed into the evaporator shell at a designated area; and (4) by preventing or reducing the occurrence of foaming inside the evaporator through anti-foaming surfaces, such as by the use of refrigerant phobic and lubricant phobic material(s). Refrigerant management can in turn improve the thermal performance and overall efficiency of the evaporator.

The present invention relates to an apparatus and a method for evaporating liquids containing potentially explosive impurities of lower volatility than the actual liquid compound. The set-up of the evaporator according to the invention allows its operation with complete evaporation of a liquid without formation of a liquid sump of not yet evaporated liquid.

Generally, management of refrigerant in an evaporator of an HVAC chiller is described. Methods, systems, and apparatuses to manage refrigerant in an evaporator can include one or combination of the following approaches: (1) by use a refrigerant displacement array to physically prevent refrigerant from residing where the array is positioned; (2) by control of the interstitial velocity of refrigerant flow within the volume of the shell of an evaporator; (3) by a phase biased distribution of the refrigerant mixture, so that a gaseous portion is uniformly distributed into the evaporator shell, while liquid refrigerant and oil is distributed into the evaporator shell at a designated area; and (4) by preventing or reducing the occurrence of foaming inside the evaporator through anti-foaming surfaces, such as by the use of refrigerant phobic and lubricant phobic material(s). Refrigerant management can in turn improve the thermal performance and overall efficiency of the evaporator.

An evaporator includes an enclosure with a lateral confinement shell with a substantially horizontal axis, which internally accommodates a dispenser of a coolant fluid and at least one tube bundle, which is arranged below the dispenser. The evaporator further includes exchanger tubes, which are passed through by a fluid to be cooled. At least one first group of exchanger tubes is arranged along rows which extend on substantially horizontal and mutually superimposed planes. The exchanger tubes of each row are arranged in at least one respective tray for collecting and distributing the liquid coolant fluid. Each tray has, along at least one first longitudinal edge, at least one first containment sidewall which is adapted to allow the liquid coolant fluid contained therein to fall by overflowing into an underlying tray and is provided in its bottom with openings for draining the liquid coolant fluid.

A coolant supply device includes a coolant tank having first and second coolant reservoirs arranged in parallel with a predetermined space therebetween and a communicating part arranged between the first and second coolant reservoirs to allow them to communicate with each other, and formed to have a U-shaped overall shape. The coolant supply device further includes pumps pumping up coolant from the second coolant reservoir and supplying the coolant to predetermined destinations. The coolant supplied by the pumps is returned to the first coolant reservoir and flows into the second coolant reservoir through the communicating part. The first coolant reservoir has a first agitating nozzle body disposed therein for discharging coolant to assist a flow of coolant flowing toward the communicating part, and the second coolant reservoir has a second agitating nozzle body disposed therein for discharging coolant to assist a flow of coolant flowing therein from the communicating part.

An evaporator (2) comprising: a casing (5); a plurality of heat transfer tubes (12) which are immersed in a liquid refrigerant (RL) in a liquid-phase region (A1) and in the interior of which a fluid having a higher temperature than that of the liquid refrigerant (RL) flows; and a demister (7) which is provided so as to cover from above the liquid surface (Ls) of the liquid refrigerant (RL) accommodated in the liquid-phase region (A1), and which traps liquid droplets contained in evaporated gas refrigerant (RG). The demister (7) comprises inclined sections (13) which, when viewed in a cross section intersecting the axial line (O2) of the heat transfer tubes (12), separate from the liquid surface (Ls) toward the center portion of the casing (5) along the liquid surface (Ls).

A heat exchanger (10) of heat pipe configuration for transferring heat between a first and second process streams via a heat transfer fluid comprises: at least one first process stream passage (19); at least one second process stream passage (29); and a shell (11) enclosing the first and second process stream passages (19, 29) within a volume (55). The volume (55), as a result of a heat transfer process, is fully filled with both vapour and liquid phases of the heat transfer fluid. The first and second process stream passages (19, 29) are spaced by a disengagement zone (50) enabling gravitational separation of said vapour and liquid phases and limiting accumulation of liquid phase heat transfer fluid about the first process stream passage(s) (19). Such heat exchangers can be used, among other applications, to replace a flash cooling stage in a Bayer process plant.

A heat exchanger, such as a flooded evaporator, comprises a shell extending along a longitudinal axis (X), an inlet pipe and an outlet pipe, through which respectively enters (F1) and exits (F2) a refrigerant flow, and a bundle of pipes crossing the shell along the longitudinal axis (X), and comprising a refrigerant flow diffuser provided inside the shell downstream the inlet pipe, the refrigerant flow diffuser extending along the longitudinal axis (X) and comprising openings through which the refrigerant flows. The refrigerant flow diffuser comprises a moving element and a stationary element, the moving element being movable with respect to the stationary element under action of a pressure force (FP) exerted by the refrigerant flow so that the refrigerant flow going through the openings is adjusted and a differential refrigerant pressure between refrigerant pressure downstream (P2) and upstream (P1) the refrigerant flow diffuser is kept constant.

A suction duct is disposed within a shell and tube heat exchanger. The suction duct is located relatively high and above the tube bundle so as to not entrain liquid or droplets that may be splashing and spraying upward. The suction duct is configured with an area schedule in fluid communication with a flow path inside the suction duct. The flow path is in fluid communication with an outlet of the shell. This is advantageous relative to traditional top of the shell outlets which generally have higher vertical footprints. The area schedule of the suction duct can facilitate and/or maintain relatively smooth vapor flow within the shell. The area schedule can achieve vapor flows that have some uniformity along the length of the shell, which can manage and/or avoid localized vapor flow and/or local currents, such as where high velocity may be present and where entrainment can result.