HOT BOX FOR ASPHALT

• US 3,721,226 A
• Filed: 08/30/1971
• Issued: 03/20/1973
• Est. Priority Date: 08/30/1971
• Status: Expired due to Term

• Current Assignee: Herman T. Childree, Stewart T. Trawick
• Original Assignee: Herman T. Childree, Stewart T. Trawick
• Inventors: Childree, Herman T., Trawick, Stewart T.
• Primary Examiner(s): Perlin, Meyer
• Assistant Examiner(s): Capossela, Ronald C.
• Application Number:
  US05/176,108
• Time in Patent Office: 568 Days
• Field of Search: 126/343.5A,343.5R 122/DIG.11
• US Class Current: 126/343.50A
• CPC Class Codes: E01C 19/10 Apparatus or plants for premixing or precoating aggregate or fillers with non-hydraulic binders, e.g. with bitumen, with resins, i.e. producing mixtures or coating aggregates otherwise than by penetrating or surface dressing; Apparatus for premixing non-hydraulic mixtures prior to placing or for reconditioning salvaged non-hydraulic compositions E01C19/08, E01C19/21, E01C21/00, E01C23/065 take precedence
• CPC Class Codes: E01C 23/06 Devices or arrangements for working the finished surface working freshly laid paving E01C19/42 - E01C19/44, E01C23/02; mining picks E21C35/18; Devices for repairing or reconditioning the surface of damaged paving; Recycling in place or on the road

Abstract

A hot box for maintaining asphalt at elevated temperatures including a closed and insulated container, a service apron, a heat exchanger for heating the container, a burner capable of producing high velocity hot gases for driving a mixture of hot gases and air through the heat exchanger and a temperature control system.

Claims

1. A hot box for maintaining asphalt at elevated temperatures comprising, a container having top, bottom and side walls defining a holding chamber for asphalt, burner means generating high velocity hot gases, and a heat exchanger between the burner means and the container, said heat exchanger including side walls contiguous with and extending down from the side walls of said container and a bottom wall coacting with the side walls and the bottom wall of the container to define a chamber, a firing tube extending centrally into the heat exchange chamber separating same into two heat exchange compartments, said firing tube having an inlet port and a pair of outlet ports, one outlet port for each compartment, said burner means being arranged at the inlet port to discharge its hot gases therein and to induce air into the firing tube and drive a mixture of air and gases through the heat exchanger, baffle means in each compartment defining a continuously reversing gas flow path, and discharge ports in the compartment side walls to discharge the gases therefrom.

2. The combination of claim 1, wherein deflector means is provided in the firing tube to split the mixture of air and gases into the compartments.

3. The combination of claim 1, wherein the container is formed to be essentially airtight and weatherproof.

4. The combination of claim 1, and a stack connected to the outlet ports to exhaust the mixture of air and combustion gases above the container.

5. The combination of claim 1, wherein the side walls of the container and heat exchanger are insulated, and the heat exchanger extends under the entire bottom wall of the container.

6. The combination of claim 1, wherein an adjustable service apron is provided to hold the hot asphalt during an interim period of time after removal from the hot box but before application to a pothole, said service apron being hinged and thus capable of being tilted to allow asphalt to be dropped from it to the road service at adjustable rates.

7. The combination of claim 6, and temperature sensing means in the stack for controlling the operation of the burner.

8. The combination of Claim 6, wherein the burner produces hot gases having a temperature of about 2,800*F and a velocity of 200 to 300 feet per second.

9. An asphalt hot box comprising a container for asphalt defined by top, bottom and side walls, a heat exchanger directly below the container for transferring heat to the asphalt in the container, said heat exchanger including side walls aligned with the side walls of the container, a bottom wall and being open at the top in direct communication to the bottom wall of the container, whereby gases flowing through the heat exchanger scrub the bottom wall of the container, a fire tube extending centrally through the heat exchanger having an inlet port at one end and a pair of outlet ports at the other end and separating the exchanger into two heat exchange compartments, the outlet ports intercommunicating the heat exchange compartments and the fire tube, baffle means in the heat exchange compartments for causing a circuitous flow path for hot gases, exhaust ports for the heat exchange compartments leading to a stack, and means generating and driving a mixture of air and hot gases into said inlet port and through said heat exchanger.