Enhanced Heat Management via Auger in a Pipe

This application claims the benefit under 35 U.S.C. 119 (e) of U.S. Provisional Patent Application No. 63/643,570 filed May 7, 2024, the entire disclosure of which is hereby incorporated herein by reference.

This invention generally relates to heat management systems. More specifically, this invention relates to using augers in pipes to enhance heat management and reduce costs.

Heat transfer is a critical component of many chemical, electrochemical, and industrial processes. The global heat transfer equipment market size is $14.50 billion in 2022 and is projected to reach $21.40 billion by 2031. Clearly, it is desirable and advantageous to use simple and inexpensive designs to enhance heat management and reduce both capital costs and operational costs at the same time.

The system and method of this disclosure are developed to adjust fluid flow while enhancing heat transfer using static augers in pipes, which are inexpensive and effective.

Herein discussed is a heat management system comprising a pipe and a static auger inside the pipe, wherein the pipe has an inner diameter of d, wherein the auger has an outer diameter D and a pitch P, wherein the ratio of D/P is no less than 1, and wherein the auger outer diameter D is no less than 90% of the pipe inner diameter d. In an embodiment, the ratio of D/P is in the range of 2-10, or 2-5, or 2-4, or 5-10.

In an embodiment, the auger has one or more flutes, and wherein the flute surfaces have a roughness of 50-1000 microns. In an embodiment, the auger is made from a material having high temperature resistance and corrosion resistance. In an embodiment, the material comprises stainless steel, carbon steel, Monel, Inconel, Incoloy, Hastelloy, ceramics, silicon carbide, alumina, and combinations thereof.

In an embodiment, the pipe is made from stainless steel, carbon steel, Monel, Inconel, Incoloy, Hastelloy, ceramics, silicon carbide, alumina, and combinations thereof. In an embodiment, the system comprises a fluid passing through the pipe, wherein the pipe heats or cools the fluid.

Also discussed herein is a method of heat management, comprising providing a pipe and a static auger inside the pipe, wherein the pipe has an inner diameter of d, wherein the auger has an outer diameter D and a pitch P, wherein the ratio of D/P is no less than 1, and wherein the auger outer diameter D is no less than 90% of the pipe inner diameter d; and passing a fluid through the pipe, wherein the pipe heats or cools the fluid. In an embodiment, the ratio of D/P is in the range of 2-10, or 2-5, or 2-4, or 5-10.

In an embodiment, the auger has one or more flutes, and wherein the flute surfaces have a roughness of 50-1000 microns. In an embodiment, wherein the flutes are treated by peening, grinding, chemicals, machining, etching, abrasion, blasting, or combinations thereof to reach a desired roughness.

In an embodiment, wherein the auger is made from a material having high temperature resistance and corrosion resistance. In an embodiment, wherein the material comprises stainless steel, carbon steel, Monel, Inconel, Incoloy, Hastelloy, ceramics, silicon carbide, alumina, and combinations thereof. In an embodiment, the pipe is made from stainless steel, carbon steel, Monel, Inconel, Incoloy, Hastelloy, ceramics, silicon carbide, alumina, and combinations thereof.

Further aspects and embodiments are provided in the following drawings, detailed description, and claims. Unless specified otherwise, the features as described herein are combinable and all such combinations are within the scope of this disclosure.

The following terms and phrases have the meanings indicated below, unless otherwise provided herein. This disclosure may employ other terms and phrases not expressly defined herein. Such other terms and phrases shall have the meanings that they would possess within the context of this disclosure to those of ordinary skill in the art. In some instances, a term or phrase may be defined in the singular or plural. In such instances, it is understood that any term in the singular may include its plural counterpart and vice versa, unless expressly indicated to the contrary.

As used herein, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. For example, reference to “a substituent” encompasses a single substituent as well as two or more substituents, and the like. As used herein, “for example,” “for instance,” “such as,” or “including” are meant to introduce examples that further clarify more general subject matter. Unless otherwise expressly indicated, such examples are provided only as an aid for understanding embodiments illustrated in the present disclosure and are not meant to be limiting in any fashion. Nor do these phrases indicate any kind of preference for the disclosed embodiment.

As used herein, compositions and materials are used interchangeably unless otherwise specified. Each composition/material may have multiple elements, phases, and components. Heating as used herein refers to actively adding energy to the compositions or materials.

The term “in situ” in this disclosure refers to the treatment (e.g., heating or cracking) process being performed either at the same location or in the same reactor. For example, ammonia cracking taking place in the electrochemical reactor at the anode is considered in situ.

As illustrated inand, a heat management system comprises a pipe (,) and a static auger (,) inside the pipe. When a fluid is passed through the pipe, the pipe either heats or cools the fluid. In some cases, the pipe is heated to temperatures of 700° C. or higher to heat the fluid flowing through. In some cases, the pipe is heated to temperatures of 800° C. or higher to heat the fluid flowing through.

Without wishing to be bound by theory, it is believed that the auger in the pipe induces turbulence in the fluid passing through the pipe and thereby enhances heat transfer from the pipe to the fluid. In, the pipe has a narrowed inletand a narrowed outlet. Pipe (,) has an inner diameter of d. Augeris shown in, wherein the augerhas a shaft, twists, an outer diameter(D), and a pitch(P). The auger pitch P is the maximum distance between two adjacent twists, preferably measured parallel to the shaft. In, augerhas one flute. In, augerhas two counter-circling flutesand.

In an embodiment, the auger outer diameter D is no less than 90% of the pipe inner diameter d. In an embodiment, the ratio of the auger outer diameter to the auger pitch (i.e., D/P) for the auger is no less than 1. In various embodiments, the ratio of D/P is in the range of 2-10, or 2-5, or 2-4, or 5-10. This is atypical of what is practiced according to conventional wisdom, wherein the D/P ratio is lower than 2 or lower than 1. The auger outer diameter to pitch ratio (D/P) is critical because lower ratios result in fluid flows that are more axially aligned, whereas higher ratios result in more tangential and swirling flows with increased pressure drop. Clearly, there is a balance to be achieved between heat transfer and pressure drop. Fluid flow rate through the pipe is another factor that would influence heat transfer and pressure drop. In various embodiments, if the auger outer diameter D is fixed, the pitch P is adjusted to optimize heat transfer against pressure drop. In general, smaller pitch leads to higher pressure drop and increased heat transfer. In various embodiments, multiple flutes are also used to optimize pressure drop and flow characteristics.

In an embodiment, the auger is made from a material having high temperature resistance and corrosion resistance. In an embodiment, the material comprises stainless steel, carbon steel, Monel, Inconel, Incoloy, Hastelloy, ceramics, silicon carbide, alumina, and combinations thereof. In an embodiment, the pipe is made from the same material as the auger, such as, stainless steel, carbon steel, Monel, Inconel, Incoloy, Hastelloy, ceramics, silicon carbide, alumina, and combinations thereof.

In an embodiment, the auger has one or more flutes, wherein the flute surfaces have a roughness of 50-1000 microns. The surface roughness of this range enhances radiative heat transfer from the pipe wall to the flute(s)/twists. The surface roughness of this range also increases turbulence in the fluid flow, further increasing the heat transfer rate from the auger to the fluid. In various embodiments, the flutes are treated by peening, grinding, chemicals, machining, etching, abrasion, blasting, or combinations thereof to reach a desired roughness.

The advantages of this heat management system are many. For example, external heaters may be used to heat the pipe, eliminating the need for an integrated heater. The external heaters are typically cheaper and more robust because the heating elements are not in direct contact with harsh fluids, such as corrosive gases. In the case of a heater failure, replacement of an external heater is much easier and cheaper than that of an integrated heater, with little to no down time for operation. As such, the heat management method and system of this disclosure reduce both capital costs and operational costs.

Example 1. Comparative example: As shown in, a 4-inch diameter pipe is connected to a 2-inch diameter pipe with the 4-inch diameter pipe heated to 850° C. and the 2-inch diameter pipe not heated. There is no auger in either of the pipes. Room temperature gasis passed into the 4-inch diameter pipe and exits the 2-inch diameter pipe asat a temperature of 512° C.

Example 2. As shown in, a 4-inch diameter pipe is connected to a 2-inch diameter pipe with the 4-inch diameter pipe heated to 850° C. and the 2-inch diameter pipe not heated. The 4-inch diameter pipe and the 2-inch diameter pipe each have an auger inside. Room temperature gasis passed into the 4-inch diameter pipe and exits the 2-inch diameter pipe asat a temperature of 720° C.

Example 3. As shown in, a 4-inch diameter pipe is connected to a 2-inch diameter pipe with the 4-inch diameter pipe heated to 850° C. and the 2-inch diameter pipe not heated. The 4-inch diameter pipe has an auger inside while the 2-inch diameter pipe has no auger inside. Room temperature gasis passed into the 4-inch diameter pipe and exits the 2-inch diameter pipe asat a temperature of 732° C.

Example 4. For the cases discussed in Examples 2 and 3, there is a significant relationship between the exit gas temperature (i.e., outlet temperature) and the mass flow rate of the gas. This is shown in. As can be seen, the slower the flow rate, the higher the exit gas temperature.

It is to be understood that this disclosure describes exemplary embodiments for implementing different features, structures, or functions of the invention. Exemplary embodiments of components, arrangements, and configurations are described to simplify the present disclosure; however, these exemplary embodiments are provided merely as examples and are not intended to limit the scope of the invention. The embodiments as presented herein may be combined unless otherwise specified. Such combinations do not depart from the scope of the disclosure.

Additionally, certain terms are used throughout the description and claims to refer to particular components or steps. As one skilled in the art appreciates, various entities may refer to the same component or process step by different names, and as such, the naming convention for the elements described herein is not intended to limit the scope of the invention. Further, the terms and naming convention used herein are not intended to distinguish between components, features, and/or steps that differ in name but not in function.

While the disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and description. It should be understood, however, that the drawings and detailed description are not intended to limit the disclosure to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of this disclosure.