METHOD AND DEVICE FOR ENERGY RECOVERY BY MANUFACTURING OF ASPHALT IN BULK

Abstract: Method and device for manufacturing of asphalt bulk masses where a substantial part of the heat energy of the furnace gases from the drying and mixing process is transferred to the bulk mass fractions before those are supplied to the drying and mixing process and where the furnace gasses by this process at the same time are cleaned for pollutions. Bulk masses are directed downwards between two parallelly arranged inclined planes (1, 5) where the lower inclined plane (1) comprising horizontally arranged downwards directed ribs (2) directing the furnace gasses to the lower side of the bulk masses and where the second inclined plane (5) comprising vertically arranged ribs (4) suctioning the cleaned furnace gases up from the bulle masses after a substantial part of the heat energy being transferred to the bulk masses. At the lower and upper ends of the inclined planes accumulations of the bulk masses (7, 11) are maintained for preventing air from the atmosphere to penetrate into the system. The bulk mass fractions thereafter are transferred to the drying and mixing process, thereby having accumulated a substantial amount of heat energy and the bitumen components being transferred with the furnace gasses, as well as other pollutions.

Description: Method and device for energy recocery by manufacturing of asphalt in bulk The invention refers to a method and a device for energy recovery by manufacturing of asphalt in bulk. Smoke gases from the manufacturing of asphalt in bulk today normally is cleaned by scrubbers or bag filters. Both principles have disadvantages influencing negatively on the preocesses operationally and ecnomically. In known scrubbers the pollutions of the gases are absorbed by a liquid, usually water. The principle includes a high energy consuption and also is dependant of water supply. A high amount of condence from the oil products create problems with packing of jets which in turn give disturbances in the system. Additionally sulphur deposits also create difficulties. Of these reasons, use of scrubbers demand a considerable amount of energy and maintainance work Bag filters on the other side have a considerable limitation in that the clothing is destroyed at temperatures exceeding about 230°C. Furthermore the compositions of bitumen will condensate and pack the clothing in the bag filters. By means of the features mentioned in the character¬ izing clause of the claims, these unfortunate reaults of prior art in addition to a considerable energy recover is received in that the heat energy of the smoke gases is used for preheating the bulk before it is supplied to the dry and mixing process. In the drawing, fig. 1 discloses schematically a total plant for manufacturing of asphalt in bulk and fig. 2 discloses a vertical section through the device according to the invention. Fig. 1 discloses a total plant for manufacturing of asphalt in bulk according to the invention. Two bulk fractions are supplied through feeding pockets 24, whereas filler is supplied from a silo 25 to a conveyor 28 which transports the bulk to the device according to the inveniton. The drawing discloses also bitumen tanks 22, an oil tank 23, doser device 27 for recirculation and a conveyor 26 for withdrawal of the end product. The waste gases from the mixing drum 29 are directed by channels 30 to the device 21. After treatment in the device, the bulk is transported by a transport means 31 to the input of the mixing drum 29. The device 21 is disclosed in vertical section on fig. 2. The conveyor 28 transports the bulk to the elon- gated funnel 6 where the bulk is distributed equally along the length of the funnel by a scraper conveyor 8. In the lowest part of the funnel 6 a packing of bulk, generally denoted 11, is created. This packing or plug prevents air from the environment in penetrating into the device 21. A cam 12 devides the bulk in the funnel into branches for treatment in symmetrically arranged sets of inclined planes. Evry set of inclined plane comprises a lower inclined plan 2 and an upper inclined plan 5 being arranged parallelly and in a distance from eachother. In one imbodiment the free distance between the planes are 200 mm and the sloping angle is 14° to the vertical.plane. Each inclined plane 1, 5 comprises a grating 3, 13 to which horizontally fixed ribs 2, 4 are arranged. The ribs 2 in the first plane 1 are arranged sloping downwards against the second plane 5, the ribs thereby partly overlapping eachother. The ribs 4 in the second inclined plan 5 are arranged vertically. The combustion gases supplied to the device from the mixing drum 29 y channels 30, are supplied to the lower side of the first inclined plane 1 and pressed through the ribs 2 against the bulk masses sliding down the inclined plane from the funnel 6. After the gases have liberated a substantial part of their heat energy to the bulk masses and at the same time being cleaned for pollutions, the gases are succed up through the ribs 4 in the second inclined plane 5 and further directed to the environment. To have the bulk masses moving downwards between the inclined planes, vibrator devices are used to vibrate the inclined planes. Further to prevent the bulk gasses packing or compressing, the lower edge of the ribs 2 are provided with teeth comprising alternating recesses and webs, the webs in a rib being arranged above the recesses in the rib beneath, the bulk masses thereby being disengaged as it falls from rib to rib. A conveyor is arranged at the bottom of the inclined planes for transportation of the bulk masses treated. The conveyor is adjusted permanently to maintain a packing or plug 7 with bulk masses, preventing air in penetrating into the system from environments. By means of the device according to the invention, a remarkable amount of energy is recovered as a substantially part of the energy in the furnace gases is transferred to the bulk masses, whereas at the same timed additionally energy consumption for cleaning the gases is avoided. Additionally bitumen substances transferred by the furnace gases are depoited in the bulk masses and recycled back to the process. SUBSTITUTE SHEET O PI

Claims: P a t e n t c l a i m s 1. Method for manufacturing of asphalt in bulk, c h a r a c t e r i z e d i n conducting a plurality of bulk mass fractions together in a layer downwards at least a first inclined plane (1) by means of gravity, to conduct furnace gases from the dry and mixing process of the asphalt in bulk masses through the layer with bulk masses for thereby to transfer heat from the gas to the masses and to clean the gasses from the enclosed binder and pollutions, and to vibrate the inclined plane(s) (1) . 2. Method according to claim 1, c h a r c t e r i z e d i n direction the furnace gases downwards against the lower side of the layer with bulk masses by directing the furnace gases out from the inclined plane (1) between horizontally arranged, partly overlapping ribs (2) in a grating (3) , being directed downwards in the flow direction of the gases. 3. Method according to claims 1-2, c h a r a c t e r - i z e d i n directing the furnace gases out from two symmetrically arranged first inclined planes (1) with a common highest point and suctioning the furnace gases up between horizontal, vertically arranged ribs (4) in a second inclined plane (5) arranged above each of the first inclined 5 planes and with a constant distance from these, thereby to ensure that the furnace gases after exiting the first inclined plane, penetrates between the bulk masses and thereafter are suctioned up in the second inclined plane. 4. Device for manufacturing of asphalt bulk masses, ^ c h a r a c t e r i z e d i n that a first inclined plane (1) comprises horizontal, partly overlapping and downwards directed ribs (2) in the inclination of the inclined plane, to direct furnace gases from the drying and mixing process of the asphalt bulk masses homogeneously 5 against the lower side of the layer of bulk masses being directed downwards the inclined plane (1) , corresponding horizontally and vertically arranged second ribs (4) in a second inclined plane (5) , arranged above the first ribs (2) of the first inclined plane (1) whereby the first and the second inclined planes being arranged parallelly to eachother and where the inclined planes (1, 5) are arranged to be vibrated. 5. Device according to claim 4, c h a r a c t e r ¬ i z e d i n that the distance between the inclined planes is arranged to be adjusted by displacing the incline planes vertically to each other. 6. Device according to claims 4-6, c h a r a c t e r - i z e d i n that ducting and suction means are provided for directing the furnace gases from the drying and mixing process for the asphalt bulk masses to the lower side of th first inclined plane, through the bulk masses in the layer between the two inclined planes, and ducting and suction menas for directing the furnace gases from the upper side of the second inclined plane. 7. Device according to claims 4-6, c h a r a c t e r ¬ i z e d i n that the first inclined plane (1) are arranged with common upper edges. 8. Device according to claims 4-7, c h a r a c t e r ¬ i z e d i n a filling funnel (6) being arranged above the first inclined plane (1) and connected with the corresponding second inclined plane (5) such that an amount of bulk masses by use is built up in the funnel, preventing the environmental air in flowing down into the funnel. 9. Device according to claims 4-8, c h a r a c t e r ¬ i z e d i n that the loser part of each rib in the lower parts of the first inclined plane (1) is provided wit recesses transcersially to the longitudinal direction of the ribs such that the mass can fall down through the recesses between the intermediate webs and that the recesses in the ribs are arranged above corresponding webs in the rig arranged below, thereby to loosen packed bulk masses. 10. Device according to claims 4-9, c h a r a c t e r - i z e d i n that a conveyor is arranged below the lowest part of each pair of first and second inclined planes (1, 5) being such arranged that a accumulation of bulk masses at the loser part of the inclined planes is maintained under use for preventing penetration of air from the outside.

Inventors: LUND IVAR, LUND, IVAR
Applicants: ANKERLOEKKEN HAMAR AS
Application year: 1983
Main classification: C10C3
IPC codes: C10C3, E01C19