METHOD, PROCESS AND APPARATUS FOR THE VERY LOW TEMPERATURE EVAPORATION SYSTEM

Abstract

The method, process and apparatus for very low temperature evaporation system novelty of the invention lies in the concept of method, process and apparatus for evaporation and concentration at very low temperature ranges from 5° C. to 80° C. to recover water vapour from liquids or solutions or industrial effluents or spentwash or industrial wastewater or juices or syrups or slurry or sludge or brine or sewer or wastewater or any other evaporative liquid materials in single or multiple effect heat exchanger arranged in horizontal or vertical manner with mechanical vapour compression system under vacuum. This very low temperature evaporation system operates at lowest temperature for maximum clean water recovery from liquids or solutions or industrial effluents or industrial wastewater. The apparatus for low temperature evaporation system eliminates or reduces the utilization of heat generation and rejection units along with other benefits like reduces water extraction from earth and energy losses.

Claims

1-10. (canceled)

11. A low temperature evaporation system for extracting water from a liquid at a temperature between 5° C. to 80° C., comprising: a plate heat exchanger; a direct contact heater or stripper column; a circulation pump; a condensate pump; a distribution assembly; a heat exchanger module comprising a plurality of plate heat exchangers; a mechanical vapor compression system comprising one or more compressors; and a forced circulation evaporator or concentrator; wherein: the plate heat exchanger is configured to receive an intake of said a liquid from a feed tank through a feed pump and increase temperature of the liquid; the direct contact heater is configured to receive the heated liquid from the plate heat exchanger and increase temperature of the liquid; the circulation pump is configured to transport the heated liquid from the plate heat exchangers of the heat exchanger module to the distribution assembly; the condensate pump is configured to transport the condensate of condensate tank collected from heat exchanger module and forced circulation evaporator to the plate heat exchanger; the distribution assembly is configured to distribute the heated liquid over the plate heat exchangers of the heat exchanger module; the heat exchanger module is configured to cause water in the heated liquid to evaporate as a vapor and condensate as a water, so that the heated liquid concentrates; the mechanical vapor compression system is configured to compress the vapor or non-condensate gases (NCG), and send the compressed vapor and NCG to the heat exchanger module; forced circulation evaporator and direct contact heater for heating, evaporation and concentration of the heated liquid; and the forced circulation evaporator is configured to collect the concentrated liquid from heat exchanger module, and feed the concentrated liquid to the heat exchanger of forced circulation evaporator through the circulation pump for further evaporation of the concentrated liquid, or release the concentrated liquid for further drying; wherein successive evaporations and concentrations of the liquid under vacuum using the compressed vapor or NCG result in recovery of clean water from effluent or wastewater.

12. The low temperature evaporation system according to claim 11, wherein the plurality of plate heat exchangers of the heat exchange module, the distribution assembly and an entrainment separator or demister pad assembly are arranged in a horizontal or a vertical configuration for proper liquid distribution and vapor separation.

13. The low temperature evaporation system according to claim 11, wherein the vapor from the heat exchanger module is compressed by the mechanical vapor compression system, the compressed vapor is fed to the heat exchanger module, and the circulation pump is further configured to transport the concentrated liquid collected from the heat exchanger module to the forced circulation evaporator so that the evaporation of the liquid occurs without use of an external heat source.

14. The low temperature evaporation system according to claim 11, further comprising a direct contact heater or stripper column, configured to further heat the liquid from the plate heat exchanger before the liquid enters the heat exchanger module for improved evaporation and concentration.

15. The low temperature evaporation system according to claim 11, wherein the heated liquid is sprayed over the plate heat exchangers of the heat exchange module by the distribution assembly, the concentrated liquid and condensed vapor are collected separately at the bottom of the plate heat exchangers, and the concentrated partial liquid is again pumped by the circulation pump over the plate heat exchangers for progressive concentrations of the liquid.

16. The low temperature evaporation system according to claim 15, wherein the concentrated liquid of the last effect of heat exchanger module is transferred to the forced circulation evaporator for further evaporation and concentration using compressed vapor or compressed non-condensate gases, so as to make the progressive concentrations energy efficient.

17. The low temperature evaporation system according to claim 13, wherein temperature of the vapor and non condensate gases (NCG) are increased when compressed by the mechanical vapor compression system, and the compressed vapor and NCG of high temperature are fed to the heat exchanger module, forced circulation evaporator and direct contact heater in the process of evaporation and concentration.

18. A process for extracting water from a liquid at a temperature between 5° C. to 80° C. in a low temperature evaporation system, wherein the low temperature evaporation system comprises a plate heat exchanger, a direct contact heater, a circulation pump, a condensate pump, a distribution assembly, a heat exchanger module including a plurality of plate heat exchangers, a mechanical vapor compression system including one or more compressors, and a forced circulation evaporator, wherein the process comprises: the plate heat exchanger receiving an intake of said liquid from a feed tank through a feed pump and increasing temperature of the liquid; the circulation pump transporting the heated liquid from the plate heat exchangers of heat exchanger module to the distribution assembly; the distribution assembly distributing the heated liquid to the plate heat exchangers of the heat exchange module; the heat exchange module causing water in the heated liquid to evaporate as a vapor and condensate as water, so that the heated liquid concentrates; the mechanical vapor compression system is configured to compress the vapor or non-condensate gases (NCG), and send the compressed vapor and NCG to the heat exchanger module; forced circulation evaporator and direct contact heater for heating, evaporation and concentration of the heated liquid; and the forced circulation evaporator is configured to collect the concentrated liquid from heat exchanger module, and feed the concentrated liquid back to the heat exchanger of forced circulation evaporator through the circulation pump for further evaporation of the concentrated liquid, or release the concentrated liquid for further drying; wherein successive evaporations and concentrations of the liquid under vacuum using the compressed vapor or NCG result in recovery of clean water from effluent or wastewater.

19. The process according to claim 18, wherein in the low temperature evaporation system, the plurality of plate heat exchangers of the heat exchange module, the distribution assembly and an entrainment separator or demister pad assembly are arranged in a horizontal or a vertical configuration for proper liquid distribution and vapor separation.

20. The process according to claim 18, wherein the vapor from the heat exchanger module is compressed by the mechanical vapor compression system, the compressed vapor is fed to the heat exchanger module, and the process further comprises: the circulation pump transporting the concentrated liquid collected from the plate heat exchangers of the heat exchanger module to forced circulation evaporator, so that the evaporation of the liquid occurs without use of an external heat source.

21. The process according to claim 18, wherein the low temperature evaporation system further comprises a direct contact heater or stripper column, and the process further comprises: the direct contact heater or stripper column heating the liquid from the plate heat exchanger before the liquid enters the heat exchanger module for better evaporation and concentration.

22. The process according to claim 18, wherein the distribution assembly distributing the heated liquid to the plate heat exchangers of the heat exchange module comprises: the distribution assembly spraying the heated liquid to the plate heat exchangers of the heat exchange module; wherein the concentrated liquid and condensed vapor are collected separately at the bottom of the plate heat exchangers, and the concentrated liquid is again pumped by the circulation pump over the plate heat exchangers for progressive concentrations of the liquid.

23. The process according to claim 22, wherein the concentrated liquid of the last effect is transferred to the forced circulation evaporator for further evaporation and concentration using compressed vapor or compressed non-condensate gases, so as to make the progressive concentrations energy efficient.

24. The process according to claim 20, wherein temperature of the vapor and non-condensate gases (NCG) is increased when compressed by the mechanical vapor compression system, and the compressed vapor and NCG of high temperature are fed to the heat exchanger module in the process of evaporation and concentration.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0049] FIG. 1: Front view of vertical low temperature evaporator

[0050] FIG. 2: Enlarge front view of vertical low temperature evaporator

[0051] FIG. 3: Enlarge top view of compression system of low temperature evaporator

[0052] FIG. 4: 3D transparent view of vertical low temperature evaporator

[0053] FIG. 5: Schematic diagram of vertical low temperature evaporation system

[0054] FIG. 6: Isometric view of horizontal single effect low temperature evaporator

[0055] FIG. 7: Front view of horizontal single effect low temperature evaporator

[0056] FIG. 8: Process flow of horizontal multi-effect low temperature evaporator

[0057] FIG. 9: Isometric view of horizontal multi-effect low temperature evaporator

[0058] FIG. 10: Front view of horizontal multi-effect low temperature evaporator

[0059] FIG. 11: 3D view of horizontal multi-effect low temperature evaporator

NUMBERING DETAILS

[0060] 101—Low Temperature Evaporator or Spray Electrical Dehydrator [0061] 102—Plate Pack (Plate Heat Exchanger) [0062] 103—Distribution Assembly [0063] 104—MVR Suction and Delivery Arrangement [0064] 105—MVR Booster or MVR Fan or MVR Blower or other compression or recompression system [0065] 106—Bearing Plate [0066] 107—Demister Pad Assembly [0067] 108—Feed Inlet [0068] 109—Feed Outlet [0069] 110—Feed Tank [0070] 111—Feed Pump [0071] 112—Re-circulation Out [0072] 113—Re-circulation In [0073] 114—Recirculation Pump [0074] 115—Condensate Pump [0075] 116—Condensate Outlet [0076] 117—Condensate Tank [0077] 118—NCG Outlet [0078] 119—Sight Glass [0079] 120—Light Glass [0080] 121—Man Hole [0081] 122—Impeller with Hub [0082] 123—Diffuser Vane [0083] 124—Dish and Flanges [0084] 125—Dish End [0085] 126—Mechanical Seal [0086] 127—Catcher [0087] 128—PHE (Plate Heat Exchanger) [0088] 129—Direct Contact Heater (DCH)/Stripper Column [0089] 130—Batch Evaporator/Force Circulation Evaporator [0090] 131—Rejection Tank [0091] 132—Residue

[0092] Described below referring to FIG. 1 to FIG. 11 an innovative method, process and apparatus at very low temperature evaporation is used in recycling of wastewater to clean water at lowest temperature comprises plate heat exchanger or plate packs and mechanical vapour re-compression system arranged in horizontal or vertical manners implementing the process, method and apparatus in accordance with the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0093] The installation shown in FIG. 1 to FIG. 11 comprises of a low temperature evaporator (101) comprises plate packs (102) and mechanical vapour recompression (105) made of an outer stainless steel shell mounted upon a bearing plate (106). The evaporation liquids or solutions or feed or industrial effluents or spentwash or industrial wastewater or juices or syrups or slurry or sludge or brine or sewer or wastewater or any other evaporative liquid materials in single or multiple effect heat exchanger (102) arranged in horizontal or vertical manner with mechanical vapour compression system (105) under vacuum in which feed is conveyed through the feed inlet (108) by feed pump (111) from feed tank (110) to the plate heat exchanger (128). This hot feed is fed to the direct contact heater (DCH)/stripper column (129) and feed to heat by the compressed non-condensate gas or compressed vapours or vapours of the evaporation system or feed can be directly send to the distribution assembly (103) depending upon the types of the feed. After maintaining the certain level of feed in the distribution assembly (103), the feed is sprayed on the plate packs (102) of single or multi-effect stages arranged in horizontal or vertical manner with the help of recirculation pump and then evaporation phenomena takes place due to temperature difference in the feed and inlet compressed vapours which is coming from the MVR suction and delivery arrangement (104) after re-compression by MVR fan (105). The concentrated liquid is collected at the bottom of the low temperature evaporator and recirculated and partially transferred to the next effect for further concentration. After the desired concentration the feed is transferred through the recirculation pump to the force circulation evaporator (130) or batch evaporator in single or multi-effects arrangement for further evaporation and concentration. In the forced circulation evaporator, compressed vapours of MVR fan (105) or non-condensate gas or both have been used as a heating media for further evaporation and concentration. Concentrate is collected in the bottom of the forced circulation evaporator (130) in rejection tank (131) as residue (132) and generated water vapours are passed through the demister pad assembly (107) for separation of vapours and liquids. After condensation of water vapours, clean water is collected at the bottom of each plate pack (102) of low temperature evaporator and forced circulation evaporator along with batch evaporator and taken out through the condensate outlet (116) into the condensate tank (117) by condensate pump (115). The feed collected at the bottom of the low temperature evaporator or spray electrical dehydrator (101) is carried out through re-circulation outlet (112) and sent to the distribution assembly (103) placed on top of the plate pack (102) through re-circulation inlet (113) by recirculation pump (114). The distribution assembly (103) which consists of at least two and ideally three distribution plates that create a constant fluid flow into the plate pack (102) below which is essential in the formation of the liquid failing film effect on the surface of the plates. A distribution assembly (103) of demister pad (107) are fitted as a vapour-liquid separator which helps to enhance the removal of liquid droplets entrained in the vapour stream. Condensate outlet (116) and NCG outlet (118) are used to continuously remove the condensate and other non-condensable gases through the catcher (127) from the low temperature evaporator (101).

[0094] A sight glass (119), a light glass (120) and a manhole (121) are fitted for the easy monitoring and maintenance of the low temperature evaporator (101). The installation of FIG. 3 which depicts the MVR arrangement (104) with MVR (105) comprises of an impeller (122) mounted with a hub whose purpose of this is to minimize leakage from the discharge side of the pump casing to the suction side. The diffuser vane (123) is attached next to the impeller hub to increase the efficiency of the impeller (122) by allowing a more gradual expansion and less turbulent area. The MVR arrangement (104) is mounted on the dished ends (125) with flanged dish (124) and dish ends (125), with a mechanical seal (126) that helps join systems or mechanisms together by preventing leakage and containing pressure attached with the extended shaft of the motor mounted on top of the evaporator, fused with the shell of the low temperature evaporator (101) to avoid any external piping or structure, with opening for water in/out for the cooling of the motor and MVR arrangement (104).