Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F5/00—Elements specially adapted for movement
  • F28F5/04—Hollow impellers, e.g. stirring vane
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
  • B65G33/00—Screw or rotary spiral conveyors
  • B65G33/08—Screw or rotary spiral conveyors for fluent solid materials
  • B65G33/14—Screw or rotary spiral conveyors for fluent solid materials comprising a screw or screws enclosed in a tubular housing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
  • B65G33/00—Screw or rotary spiral conveyors
  • B65G33/24—Details
  • B65G33/26—Screws
  • B65G33/30—Screws with a discontinuous helical surface
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
  • F28D11/00—Heat-exchange apparatus employing moving conduits
  • F28D11/02—Heat-exchange apparatus employing moving conduits the movement being rotary, e.g. performed by a drum or roller
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
  • F28D11/00—Heat-exchange apparatus employing moving conduits
  • F28D11/02—Heat-exchange apparatus employing moving conduits the movement being rotary, e.g. performed by a drum or roller
  • F28D11/04—Heat-exchange apparatus employing moving conduits the movement being rotary, e.g. performed by a drum or roller performed by a tube or a bundle of tubes
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
  • F28D7/00—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall
  • F28D7/10—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits being arranged one within the other, e.g. concentrically
  • F28D7/106—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits being arranged one within the other, e.g. concentrically consisting of two coaxial conduits or modules of two coaxial conduits
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F5/00—Elements specially adapted for movement
  • F28F5/06—Hollow screw conveyors
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
  • B65G33/00—Screw or rotary spiral conveyors
  • B65G33/08—Screw or rotary spiral conveyors for fluent solid materials
  • B65G33/14—Screw or rotary spiral conveyors for fluent solid materials comprising a screw or screws enclosed in a tubular housing
  • B65G33/18—Screw or rotary spiral conveyors for fluent solid materials comprising a screw or screws enclosed in a tubular housing with multiple screws in parallel arrangements, e.g. concentric
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
  • Y02P70/10—Greenhouse gas [GHG] capture, material saving, heat recovery or other energy efficient measures, e.g. motor control, characterised by manufacturing processes, e.g. for rolling metal or metal working

Definitions

• the invention relates to the construction of a helical heat exchanger for the transfer of heat between two pourable materials, which can be used in particular in the production of building materials and in energy technology.
• the SNCR method is a method for reducing the nitrogen content in emissions from power plants that burn coal, biomass or waste.
• Ammonia water or urea is injected into the furnace of the boiler, whereby the flue gases react with nitrogen oxides at temperatures of 760 ° C to 1000 ° C.
• the end products of this reaction are nitrogen, carbon oxide and water.
• undesired ammonia compounds are formed, which condense on the surface of the fly ash at lower temperatures and form ammonia salts.
• the salts limit the use of the ashes in construction, because when water or any other alkali, e.g. calcium, is added, ammonia salts dissolve, which results in an unpleasant odor in the building material.
• the RU 2616630 presents a system for the use of municipal waste, in which the material is transported with a screw conveyor through a cylindrical pyrolysis chamber.
• a heating medium flows through a hollow shell of the chamber - in addition, exhaust gases from a combined heat and power unit heated to a temperature of 1100 ° C. It is a screw heat exchanger, but its construction does not allow heat transfer between bulk materials of different temperatures.
• a fermentation device which is formed by a cylindrical container, in the vertical axis of which a screw mixer is attached, a spiral band being welded to the inner wall of the container. This arrangement only serves to completely mix the liquid contents of the container.
• the invention is based on the object of designing a construction of a heat exchanger which enables the sensible heat contained in a bulk material to be used to preheat another bulk material at temperatures of up to 400.degree.
• the screw heat exchanger according to the invention is formed by a tubular jacket in which a driven hollow, heat transfer surface forming shaft is rotatably mounted, which has openings at both ends, on the outer surface of which an outer spiral belt for conveying a material through a gap between the shaft and the Sheath is welded and on the inner surface of which an inner spiral-shaped belt is welded for the conveyance of a material to be transferred to its sensible heat, the belts being wound in the reverse direction of winding.
• the heat exchanger there is an entry for the material into the gap between the jacket and the hollow shaft and an exit for the material from the cavity of the shaft at one end of the heat exchanger, the gap at the other end of the heat exchanger with the cavity the shaft is connected and wherein the heat exchanger is provided at the other end with means for heating the material.
• the heat exchanger is provided at one end with an inlet for the material to be heated into the gap between the jacket and the hollow shaft, as well as with an outlet for the material to be transferred from the cavity of the shaft, whereby it is provided at the other end with the outlet for the heated material, and wherein the cavity of the shaft is connected at the other end to a supply of its sensible heat to be transferred material.
• the inner spiral belt can preferably protrude from the cavity of the shaft at the other end of the heat exchanger so that it engages the material or building material that is located in the space connecting the cavity and the gap or in the material supply.
• the gap between the jacket and the hollow shaft is provided with air channels for the discharge of gaseous products.
• the bearings of the hollow shaft are provided with feed lines for sealing air.
• Both edges of the gap between the jacket and the hollow shaft are preferably provided with pairs of circular rings for a supply of the separating air.
• the spiral belts on the outer and inner surfaces of the hollow shaft are interrupted in another embodiment of the heat exchanger, and in this case the belt sections can be bent at their rear ends against the sense of the rotations of the shaft or provided with openings in the contact lines with the shaft be.
• the invention thus represents the construction of a continuously operating heat exchanger which enables the transfer of heat between bulk materials at different temperatures. In contrast to the known heat exchangers for bulk masses, the heat transfer takes place directly between the masses, with no heat transfer medium being necessary.
• the principle of the heat exchanger according to the invention thus consists in a pair of spiral-shaped reversely wound belts which are welded to the inner or outer wall of a rotating hollow shaft and which convey the material along the wall of the shaft in reverse directions.
• the heat is transferred from one material to another at different temperatures through the wall of the hollow shaft.
• the materials move in countercurrent, which contributes to the high efficiency of the heat exchanger.
• Fig. 1 is a longitudinal section through a screw heat exchanger in which the
• Bulk material is first heated by means of an external heat source until it has reached the temperature required for the unwanted accompanying substance to flow out, and then the sensible heat acquired in the heated material is used to preheat the incoming material,
• Fig. 2 is a longitudinal section through another embodiment of the
• Screw heat exchanger designed to cool a hot, pourable end product, e.g. in the production of cement, lime or gypsum, and to simultaneously transfer its sensible heat to the incoming material
• the screw heat exchanger according to FIGS. 1 and 2 is formed by a tubular jacket 1 in which a rotatably mounted, driven hollow shaft 4 is mounted, which forms a heat transfer surface and is provided with openings 5 at both ends.
• An outer spiral-shaped belt 6 is welded to the outer surface of the hollow shaft 4 and, when the shaft 4 rotates, conveys a material to be heated through a gap 7 between the jacket 1 and the shaft 4 to the left.
• An inner spiral-shaped belt 8 is welded to the inner surface of the hollow shaft 4, which, when the shaft 4 rotates, conveys the material to be cooled and its sensible heat to be transferred through the inner space of the shaft 4 to the right.
• the belts 6, 8, which actually represent two screw conveyors, are wound in the opposite direction of winding.
• the heat exchanger according to FIG. 1 is intended for the temporary heating of the material and its subsequent cooling.
• An inlet 9 for the material to be heated into the gap 7 between the jacket 1 and the shaft 4 and an outlet 10 for the cooled material from the inner space of the shaft 4 are located here at the right end of the heat exchanger.
• a gap 11 is formed which connects the gap 7 with the inner space of the shaft 4.
• an external heat source 12 which is used to reheat the material.
• This can be, for example, a gas or oil burner or a heat exchanger that uses waste heat.
• the heat exchanger according to FIG. 2 is intended to use the sensible heat of a freshly burned building material.
• the inlet 9 for the material to be heated into the gap 7 between the jacket 1 and the shaft 4 and the outlet 10 for the cooled building material from the inner space of the shaft 4 are located here at the right end of the heat exchanger.
• the inner space of the shaft 4 is connected to a supply 14 of a hot building material, for example a clinker from a cement kiln, which is supposed to transfer its sensible heat.
• the inner spiral belt 8 protrudes from the cavity of the shaft 4 at the other end of the heat exchanger and thus engages in the material that is in the gap 11 or in the feed 14 of the building material is located. In this way, the supply of material into the inner space of the shaft 4 is supported.
• the gap 7 between the jacket 1 and the hollow shaft 4 is provided with air ducts 15 for the removal of gas products.
• shaft bearings 2 are provided with feed lines 16 for the sealing air, and the edges of the gap 7 between the jacket 1 and the shaft 4 are provided with pairs of circular rings for the supply 17 of separating air.
• the outer belt 6 attached to the outer surface of the shaft 4 is separated into sections - see Figs. 3 to 5. These sections can then be bent at their rear ends against the sense of the rotations of the shaft 4 - see Fig. 4, optionally provided with openings in the contact lines with the shaft 4 - see Fig. 5.
• the material intended for heating is fed through the inlet 9 into the gap 7 between the jacket 1 and the hollow shaft 4, in which the spiral-shaped outer belt 6 welded to the shaft 4 rotates, which moves the material through the unheated section of the gap 7 pushes to the left.
• the material is heated to the target temperature in the end section which is provided with the external heat source 12.
• the material fills the gap 11 and enters the inner space of the shaft 4, where the inner belt 8, which is wound in the opposite direction, pushes it to the right to the outlet 10.
• the material transfers the assumed sensible heat through the wall of the shaft 4 to the material moving through the gap 7.
• the sublimed component such as ammonia and its compounds
• the sublimed component is discharged through air channels 15 discharged from the material for neutralization.
• the material then falls through the opening 5 into the outlet 10 at the right end of the heat exchanger.
• a small amount of sealing air is fed to the bearings at both ends of the heat exchanger through the supply lines 16.
• a small amount of separating air is fed in between the circular rings which separate the gap 7 from the exit space.
• the heat exchanger is provided with thermal insulation 18.
• the media move in countercurrent.
• the building material of high temperature passes through the feed 14 for the hot building material into the heat exchanger and is drawn into this space by means of the inner belt 8, which protrudes from the inner space of the shaft 4.
• the building material is then pushed from left to right by means of the inner belt 8 when the shaft 4 rotates, transfers its sensible heat via the wall of the shaft 4, its temperature drops and it falls at the end of the shaft 4 through the opening 5 into the heat exchanger outlet 10
• the cold pourable material (charge) is fed through the inlet 9 to the gap 7 and pushed through it to the left.
• the preheated material then exits the heat exchanger through outlet 13.
• the spiral belts 6, 8 can be interrupted - see Figures 3 to 5 - and their belt sections welded to the inner surface of the hollow shaft 4 at a suitable angle can be shaped. At their rear ends they can be bent against the direction of the rotation of the shaft 4 - see FIG. 4, or provided with openings in the contact lines with the shaft 4 for the purpose of shaking the material - see FIG. 5. Shaking the material on the wall of the shaft 4 increases the heat transfer via the shaft wall and thereby the efficiency of the heat exchanger. The heat exchanger must be operated at temperatures above the condensation point.
• the heat exchanger according to the invention was designed in two variants:
• the heat exchanger is used to use the sensible heat of a hot, pourable building material emerging from a production process, and to preheat a raw material that enters the process.
• the system can be used in the cement industry, where it is necessary to cool the escaping building material from a high temperature to a safe level.
• the heat exchanger according to the invention shows its advantages particularly in companies where work is carried out continuously with larger amounts of material. Such a case are in particular heat exchangers for carrying out denitrification methods in which it is necessary to remove ammonium salts in a thermal manner from the ash leaving the combustion process.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• General Engineering & Computer Science (AREA)
• Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
• Muffle Furnaces And Rotary Kilns (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=74187061

Family Applications (1)

Country Status (2)

Cited By (1)

Citations (6)

Family Cites Families (3)

• 2020
  • 2020-03-17 CZ CZ2020-146A patent/CZ2020146A3/cs unknown
  • 2020-12-29 WO PCT/CZ2020/000056 patent/WO2021185388A1/de active Application Filing

Patent Citations (6)

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