System and method for encapsulating high temperature surface portions of a machine component

An anti-explosion and anti-fire system is disclosed, the system comprising an encapsulant disposed to cover high temperature surface portions of a component; a conduit in thermal connection with the encapsulant; and a heat transfer fluid disposed within the conduit. A diesel engine is disclosed for an underground mine, the engine comprising an encapsulant disposed to cover high temperature surface portions of a cylinder head; a conduit in thermal connection with the encapsulant; and a heat transfer fluid disposed within the conduit. A method for encapsulating high temperature surface portions of a cylinder head is disclosed, the method comprising positioning a conduit adjacent the head; positioning an encapsulant in thermal connection with the head and the conduit; and transferring heat from high temperature portions to prevent gasses, coal dust, fuel, oils or other combustible material in an underground mine from contacting portions at temperatures above an explosion or fire safety limit.

BACKGROUND

Diesel engines power a wide variety of vehicles and equipment used in various underground and mining applications due to their improved safety and efficiency over electrically powered vehicles and equipment. However, diesel engines are not without their disadvantages and there remain several problems that need to be solved before diesel engines can be fully utilized in such environments.

Diesel engines and other mechanical components used in various underground and mining applications generally include high temperature surface portions which may exceed a safety limit for explosion of gasses or fire hazard from coal dust, fuel, oils or other combustible materials present in the underground mine. In order to be certified explosion proof for use in underground or mining applications, the Mine Safety and Health Administration (MSHA) limits the maximum surface temperature of diesel engines and other mechanical components. However, regulation of such high temperature surface portions of diesel engines and other mechanical components can be difficult inasmuch as MSHA has not approved thermal regulation designs with blankets or insulation.

There are several safety concerns about the use of blankets or insulation for regulating high temperature surfaces of diesel engines and other mechanical components. One issue is inadequate sealing of the blankets or insulation to the engine or other component. Another issue is possible removal or wear of the blankets or insulation previously disposed on the engine or other component. Each of these issues may allow gasses, coal dust, fuel, oils or other combustible materials present in an underground mine to contact hot surfaces. Still another issue is that blankets or insulation only shield, and do not dissipate, heat present at hot surfaces of diesel engines or other mechanical components.

SUMMARY OF THE INVENTION

In one embodiment, there is provided an anti-explosion and anti-fire system for thermal regulation of high temperature surface portions of a machine component used in an underground mine, the anti-explosion and anti-fire system comprising an encapsulant material disposed to cover the high temperature surface portions of the machine component, wherein the encapsulant material is disposed on the machine component to prevent combustible material in the underground mine from contacting the high temperature surface portions of the machine component, and wherein the encapsulant material transfers heat away from the high temperature surface portions of the machine component; a fluid conduit in thermal connection with the encapsulant material, wherein the fluid conduit receives at least a portion of the heat transferred away from the high temperature surface portions of the machine component by the encapsulant material; and a heat transfer fluid disposed within the fluid conduit, wherein the heat transfer fluid transfers at least a portion of the heat received by the fluid conduit from the encapsulant to another location away from the high temperature surface portions of the machine component.

In another embodiment, there is provided a diesel engine for use in an underground mine, the diesel engine comprising an encapsulant material disposed to cover high temperature surface portions of a cylinder head of the diesel engine, wherein the encapsulant material is disposed on the cylinder heat to prevent direct contact of combustible material in the underground mine with the high temperature surface portions of the cylinder head, and wherein the encapsulant material transfers heat away from the high temperature surface portions of the cylinder head; a fluid conduit in thermal connection with the encapsulant material, wherein the fluid conduit receives at least a portion of the heat transferred by the encapsulant material away from the high temperature surface portions of the cylinder head; and a heat transfer fluid disposed within the fluid conduit, wherein the heat transfer fluid transfers at least a portion of the heat received by the fluid conduit from the encapsulant to another location away from the high temperature surface portions of the cylinder head; and wherein the encapsulant material and the cylinder head are attached together to permit selective removal of the cylinder head from the engine block; and wherein dimensions of the encapsulant material, dimensions of the fluid conduit and volume of the heat transfer fluid are selected to dissipate heat at the high temperature surface portions of the cylinder head from temperatures above a safety limit for fire and explosion in the underground mine so as to prevent combustible material in the underground mine from contacting surface portions of the diesel engine at temperatures above the safety limit for fire and explosion.

In one embodiment, there is disclosed a method for encapsulating high temperature surface portions of a cylinder head of a diesel engine for regulation of temperature below a safety limit for fire and explosion in an underground mine, the method comprising positioning a fluid conduit adjacent the high temperature surface portions of the cylinder head; positioning an encapsulant material in thermal connection with the high temperature surface portions of the cylinder head and the fluid conduit, wherein the encapsulant material is positioned to cover the surface of the cylinder head so as to prevent combustible material in the underground mine from contacting the high temperature surface portions of the cylinder head above the safety limit for fire and explosion; and transferring heat from the high temperature surface portions of the cylinder head covered by the encapsulant material through a heat transfer fluid disposed within the fluid conduit to another location away from the high temperature surface portions of the cylinder head so as to prevent combustible material in the underground mine from contacting surface portions of the diesel engine at temperatures above the safety limit for fire and explosion.

In another embodiment, there is disclosed a method for forming an encapsulating layer on a mechanical component for regulation of temperature, wherein the method comprises placing a fluid conduit adjacent to high temperature surface portions of the mechanical component; placing a frame component adjacent to the fluid conduit so as to create a form for filling a bath of encapsulation material in a fluid state; adding encapsulation material adjacent to high temperature surface portions of the mechanical component, and removing at least a portion of the frame component after encapsulation material has hardened.

Other embodiments are also disclosed.

DETAILED DESCRIPTION OF AN EMBODIMENT

Referring toFIGS. 1 and 2, there is shown an anti-explosion and anti-fire system5for thermal regulation of high temperature surface portions10of a machine component15used in an underground mine.

In an embodiment, anti-explosion and anti-fire system5comprises an encapsulant material20disposed to cover high temperature surface portions10of machine component15. Encapsulant material20prevents combustible material, such as gasses, coal dust, fuel, oils or other materials, in the underground mine from contacting high temperature surface portions10of machine component15. Encapsulant material20transfers heat away from high temperature surface portions10of machine component15.

Referring still toFIGS. 1 and 2, there is shown a heat transfer fluid conduit25in thermal connection with encapsulant material20. Fluid conduit25is configured to receive at least a portion of the heat transferred away from high temperature surface portions10of machine component15by encapsulant material20.

Looking again atFIGS. 1 and 2, a heat transfer fluid30is disposed within fluid conduit25. Heat transfer fluid30transfers at least a portion of the heat received by fluid conduit25from encapsulant material20to another location away from high temperature surface portions10of machine component15.

In an embodiment, machine component15of anti-explosion and anti-fire system5comprises a diesel engine15A. A cylinder head15B of diesel engine15B comprises high temperature surface portions10of machine component15.

In one embodiment, encapsulant material20is disposed on high temperature surface portions10of cylinder head15B to permit selective detachment of cylinder head15B from an engine block35(FIG. 3).

Spacers40are disposed through encapsulant material20and are positioned above screw passageways45in block35. A set of screws50are selectively disposable through spacers40. Spacers40and screws50permit selective detachment of cylinder head15B from block35. In an embodiment, valve cover52may be selectively removed from cylinder head15B as encapsulant material20does not cover the bottom portion of valve cover52.

Referring toFIG. 2, encapsulant material20is disposed on the cylinder head15B to leave uncovered exhaust gas passageways55.

Referring toFIG. 14, and in an embodiment, there is provided an example of machine component15comprising a turbo charger15C. Anti-explosion and anti-fire system5includes encapsulation material20conforming to turbo charger15C. Fluid conduit25is disposed within encapsulation material20so as to efficiently transfer heat away from turbo charger15C.

In an embodiment, encapsulant material20is applied as a conformal coating to a transmission, a braking unit, or another component requiring temperature control.

In one embodiment, encapsulant material20may include lead. In other embodiments, encapsulant material20may include one or more of zinc, tin, copper, silver, cast iron, and cast steel.

In one embodiment, fluid conduit25may include copper tubing. In other embodiments, fluid conduit25one or more of aluminum tubing, steel tubing, galvanized steel tubing, iron tubing, stainless steel tubing, and plastic tubing.

In one embodiment, heat transfer fluid30may include a solution of water and glycol. In other embodiments, heat transfer fluid30may include one or more of water, glycol, engine oil, transmission oil, and refrigerant gas.

In an embodiment, the dimensions of encapsulant material20, the dimensions of fluid conduit25and the volume of heat transfer fluid30are selected to dissipate heat at the high temperature surface portions10of the machine component15from temperatures above a safety limit for fire and explosion in the underground mine so as to prevent combustible material, such as gasses, coal dust, fuel, oils or other materials, in the underground mine from contacting surface portions of the anti-explosion and anti-fire system5above the safety limit for fire and explosion.

Generally, the safety limit for fire and explosion in an underground mine is 302° Fahrenheit, as this is the ignition temperature of coal dust. For other materials, the safety limit for fire and explosion may be adjusted for the particular material. Methane has an ignition temperature of about 1000° Fahrenheit. However, this ignition temperature may be exceeded if coal dust or another combustible material ignites at a low temperature and subsequently rises.

In one embodiment, encapsulant material20surrounds fluid conduit25. In an embodiment, encapsulant material20forms a tight seal with high temperature surface portions10of machine component15.

In one embodiment, a threaded shank portion57is disposed into a threaded recess59. Threaded shank portion57provides an anchor portion to attach encapsulant material20to cylinder head15B. Threaded shank portion57may extend to a height equal to or less than the height of the encapsulant material20, otherwise threaded shank portion57extends out of encapsulant material20.

In an embodiment, a frame component60(FIGS. 6,7and9–11) is provided in attachment to machine component15. Frame component60retains encapsulant material20. In one embodiment, at least a portion of frame component60is removed from machine component15after encapsulant material20covers high temperature surface portions10. In one embodiment, at least a portion of frame component60is left in attachment to machine component15after encapsulant material20covers high temperature surface portions10.

In an embodiment, there is provided a method for encapsulating high temperature surface portions10of cylinder head15B of diesel engine15A for regulation of temperature below a safety limit for fire and explosion in an underground mine. This generally comprises positioning a fluid conduit25adjacent the surface of cylinder head15B. (SeeFIG. 4).

Next, this method generally comprises positioning encapsulant material20in thermal connection with the high temperature surface portions10of the cylinder head and fluid conduit25. (SeeFIG. 11.) Encapsulant material20is positioned to cover high temperature surface portions10of cylinder head15B so as to prevent combustible material, such as gasses, coal dust, fuel, oils or other materials in the underground mine from contacting high temperature surface portions10of the cylinder head above the safety limit for fire and explosion. Finally, this method generally comprises transferring heat from high temperature surface portions10of cylinder head15B covered by encapsulant material20through heat transfer fluid30disposed within fluid conduit25to another location away from high temperature surface portions10of cylinder head15B so as to prevent combustible material, such as gasses, coal dust, fuel, oils or materials, in the underground mine from contacting surface portions of the diesel engine at temperatures above the safety limit for fire and explosion. (SeeFIGS. 1 and 2).

Referring toFIGS. 3–13, there is shown various stages of the construction of an embodiment of system5.

Looking atFIG. 3, and in an embodiment, a method for forming an encapsulating layer20comprises replacing relatively short screws attaching cylinder head15B to block35with longer screws50together with spacers40. Screws50and spacers40permit cylinder head15B to be selectively removed from block35subsequent to placement of encapsulant material20.

Referring toFIGS. 4–8, the method for forming encapsulating layer20comprises placing fluid conduit25adjacent to high temperature surface portions10.

Looking atFIGS. 7,9and10, the method for forming encapsulating layer20comprises placing frame component60adjacent to fluid conduit25so as to create a form for filling a bath of encapsulation material20in a fluid state.

Referring toFIG. 11, and in an embodiment, the method for forming encapsulating layer20comprises adding the encapsulation material20in the fluid state up to a height equal to a top portion of the spacers40.

Looking now atFIG. 12, the method for forming encapsulating layer comprises removing at least a portion of frame component60after encapsulation material20has hardened.

InFIG. 13, there is shown an embodiment of system5with an exhaust manifold65in connection with cylinder head15B.