US 20010026732 A1
The invention is an apparatus for thawing frozen culverts that are blocked with ice and snow. It consists of three parts A pipe or tube that is attached to the inner length of the culvert by clamps or a clamp/bolt assembly and water tight end caps for the pipe. The pipe must me set slightly higher at the inlet end of the culvert than at the outlet end of the culvert. When the culvert becomes blocked with ice or snow and the water at the inlet end of the culvert is as high as the pipe. The end caps of the pipe are removed. Water flows through the pipe and creates friction. This causes the pipe to heat up and melts the ice around the pipe. Once enough ice and snow has melted around the pipe a channel will form around the pipe through which water can flow. At this point the inlet end of the pipe should be capped and the water inside the pipe allowed to drain out. Then the outlet end of the pipe should be capped. The water flowing around the pipe will eventually melt out the rest of the ice and snow in the culvert thus clearing it.
1. An apparatus for thawing frozen culverts comprising:
a hollow tube extending substantially from an intake end of a culvert to an output end of the culvert;
a removable cap sealing each end of the hollow tube; and
means for mounting the hollow tube inside the culvert such that the hollow tube is higher at the intake end than at the output end of the culvert.
2. The apparatus of claiml wherein said hollow tube comprises protrusions on the inner surface thereof.
3. The apparatus of
4. A method for thawing frozen culverts comprising the steps of:
providing a sealed hollow tube extending substantially from an intake end of a culvert to an output end of the culvert wherein the hollow tube is higher at the intake end of the culvert than at the output end thereof;
when water on the input side of the culvert rises above the hollow tube at the intake end of the culvert as a result of the culvert being frozen shut, unsealing the hollow tube so that water flows through same, the flowing water thereby causing the frozen material in the culvert surrounding the hollow tube to melt, forming a channel for water to flow through the culvert on the outside of the hollow tube.
5. The method of
resealing the hollow tube at the intake end of the culvert;
allowing water to drain out of the hollow tube; and
resealing the hollow tube at the output end of the culvert.
 The invention relates to thawing culverts or aqua ducts that are blocked with ice and or snow. More specifically it is a method and apparatus for thawing frozen or blocked road culverts which uses no electrical, hydraulic or mechanical power to thaw the ice and snow within the culvert. Water flowing inside a tube causes tube itself to heat up thus melting the ice around the tube, which will form a channel around the tube through which water can flow.
 It has several advantages over other methods of thawing frozen culverts in that it needs no outside power source and is very simple to operate. It is more compact as all of the invention is within the culvert and would be cheaper to operate and maintain than other methods of thawing frozen culverts.
 Prior to this invention there have been two patented inventions that have tried to solve the problem of road culverts blocked with ice and snow. The first is patent number “CA 2213904” invented by Robert Laurel Sterling and Rudiger Schmidt. It uses a heat cable inside the culvert to thaw a path for the melt water to flow. This idea works but it has some inherent problems with it. The costs associated with a heat cable are much higher for both initial and maintenance. The other invention is “CA 1244663” invented by Lars-uno Olsson of Sweden. This invention is a spongy cord running though the culvert. When the culvert gets plugged with ice and snow the cord can be stretched to allow melt water to flow around the cord The problem with this and the first mentioned invention is that both have to have apparatus outside the culvert, which could be hit by a grader or other road maintenance vehicle. With my apparatus there is nothing outside the culvert.
 The invention is a tube running inside the length of the culvert and is fastened to the culvert by a series of bolts and clamps. The bolts and clamps are set at differing lengths so that the water inside the tube can be drained out after being used The ends of the tube are blocked off with watertight plugs when the tube is not in use. When the watertight plugs are taken out of the ends of the tube water will flow though the tube. As the water flows though the tube it raises the temperature of the tube to the temperature of the water flowing, which is above freezing thus melting the ice and snow around the out side of the tube and inside the culvert creating a channel. After a while of this activity water will begin to flow around the tube, inside the culvert through this channel. At this time the inlet side of the tube can be blocked off and the tube drained of all water. Then the discharge end of the tube can be blocked off so it will be ready for the next use.
 Figures one.
FIG. 1 is a side view of the apparatus.
FIG. 2 is an end view of the apparatus.
FIG. 3 is an exploded view one type on clamping system.
FIG. 4 is an alternate clamping system
FIG. 5 is a second alternate clamping system.
FIG. 6 is a pictorial view of a culvert, installed in a road, blocked with ice and snow. Melt water that can't flow through culvert is shown flowing through tube.
FIG. 7 shows a tube with internal corrugations.
 A—is the tube that is mounted inside and running trough the axis of the culvert.
 B—is the mounting bolt and clamp assembly that fastens tube A to the inside of the culvert D. One mounting bolt and clamp assembly should be used every two to three feet to provide rigidity to tube A. The mounting bolts and clamps should hold the tube A at an acute angle traveling from the culvert D inlet being closest to the top of culvert D to a few inches below the top of culvert D at the outlet.
 C—water tight end cap for tube A
 D—any steel or plastic road culvert or aqua duct.
 B1—a flush mount bolt
 B2—a two piece adjustable clamp
 B3—bolt and nut used to tighten clamp (B2)
 B5—adjustable nut
 B6—clamp solidly mounted to bolt (34)
 B7—clamp tightening screw
 E—shim block
 H—road with culvert installed
 I—melted snow and ice
 J—snow and ice blocking culvert (D)
 A—a corrugated tube
 Detailed Description
 In the top of a road culvert that is either in use in a road or new. Several holes would be drilled or punched along its length and bolt (B1) inserted into the holes. The clamp assembly (B2) would be fixed to bolt (B1) and adjusted so that clamp (B1) is higher at the intake end of the culvert than at the outlet end. Tube (A) is then placed in the clamps that run along the length of the culvert and bolt (B3) is tightened to secure tube (A) inside the culvert. Alternately clamp and bolt assembly (B6) could be used instead of clamp (B2) and bolt (B1). And tube (A) placed into the clamp assembly (B6) and tightened using clamping screw (B7). Nut (B5) would then be adjusted so that tube (A) is slightly higher at the intake end of the culvert than at the out let end This adjustment would take place on the outside of culvert (D) rather than inside culvert (D) as pictured in FIG. 3. The second alternate clamping system (FIG. 5) could be used in a culvert that is already installed in a road. Holes could be drilled through the top of the culvert from the inside and shim block (E) and tube (A) held inside the culvert while clamp (F) was riveted in place with rivet (G). Threaded end caps (C) would then be put on the tube to form a watertight seal. When the culvert fills with ice and or snow and becomes blocked so no melt water can flow though it. The end caps would be removed to allow melt water to flow though the tube (FIG. 6). As the water flows though the tube, it raises the temperature of the tube to the temperature of the water flowing, which is above freezing. A tube with interior corrugations or protrusions (FIG. 7) could be used to increase the amount of friction caused by the flowing water. As the tube warms up it melts the ice and snow outside of itself and inside the culvert. Once the ice and snow around the tube has been sufficiently melted a channel would be formed This would allow water to flow through the culvert on the outside of the hollow tube thus the culvert would be reopened and the water could continue to flow washing out the ice and snow that was blocking it. At this time the inlet end of pipe should be recapped. As soon as the tube has been drained of water the outlet end of the tube should be capped Thus the tube is ready for the next time culvert fills with ice and snow and stops the flow of melt water.