US20250251127A1

US20250251127A1 - High pressure naturally aspirated tube heater

Info

Publication number: US20250251127A1
Application number: US19/045,841
Authority: US
Inventors: Andrew L. Kazmierczak; Christopher T. Smith; Brad M. Osatiuk; Travis S. McDonald; Andrew K. Roland
Original assignee: Lb White Company LLC
Current assignee: Lb White Company LLC
Priority date: 2024-02-05
Filing date: 2025-02-05
Publication date: 2025-08-07

Abstract

A heater unit assembly designed for enhanced combustion efficiency and low maintenance. The heater unit assembly comprises a heat distribution assembly connected to a burner assembly. The burner assembly comprises a gas outlet orifice aligned to a burner venturi, wherein the gas outlet orifice comprises internally a channel formed by two constricted sections with reduced diameters for controlling the pressure of the gas flowing to the burner venturi. The burner venturi is paired with an air restrictor and a burner outlet adaptor for complete naturally aspirated combustion.

Description

CROSS-REFERENCE TO RELATED APPLICATION

Priority is hereby claimed to provisional application Ser. No. 63/549,785, filed Feb. 5, 2024, which is incorporated herein by reference.

FIELD OF THE INVENTION

The present disclosure is directed to a tube heater, and more specifically, to a naturally aspirated tube heater that utilizes high pressure gases. The tube heater is designed to provide heating solutions that are both efficient and require low maintenance.

BACKGROUND

Radiant tube heaters are widely used in industrial and commercial applications to provide efficient heating solutions. These heaters typically consist of tubular structures through which combustion gases flow, thereby emitting radiant heat for applications such as space heating, industrial drying, and material processing. However, existing radiant brooders face significant challenges, including high maintenance requirements and suboptimal performance. A key issue is the inefficient mixing of gas and air in the burners, which frequently leads to incomplete combustion and the production of byproducts like soot. This incomplete combustion not only diminishes the overall performance of the heater but also contributes to the buildup of deposits, requiring frequent and intensive maintenance.
The present disclosure addresses the limitations and provides a radiant tube heater designed to optimize gas-air mixing in burners, enhance overall performance, and minimize maintenance requirements.

SUMMARY

Disclosed herein is a heater unit assembly, more specifically a tube heater, designed to enhance combustion efficiency and minimize maintenance requirements.
In one version of the disclosure, the heater unit assembly 1 comprises a burner assembly 20 configured to provide a flow of heated air. The burner assembly 20 comprises a gas outlet orifice 60 aligned with a burner venturi 70.
The gas outlet orifice 60 is positioned in a gas line leading to the burner venturi 70. The gas outlet orifice 60 comprises, internally from an inlet end to an outlet end, a gas channel comprising a wide section 602 having a first diameter A, a first constricted section 604 having a second diameter B, and a second constricted section 605 having a third diameter C, wherein the third diameter C is larger than the second diameter B but smaller than the first diameter A.
The burner venturi 70 comprises, internally from an inlet end to an outlet end, a gas channel comprising an inlet portion 701, a throat portion 702, and an outlet portion 703, wherein the throat portion 702 is narrower than the inlet portion 701 and the outlet portion 703.
The heater unit assembly 1 further comprises a heat distribution assembly 10 connected to the burner assembly 20 and configured to distribute the heat from the flow of heated air provided by the burner assembly 20.
Preferably, in the gas channel of the gas outlet orifice 60, the third diameter is about 1.1 to about 1.6 times the second diameter, and about 0.1 to about 0.2 times the first diameter. In one embodiment, the third diameter is about 1.425 times the second diameter.
The gas channel of the gas outlet orifice 60 may further comprise a tapered section 603 between the wide section 602 and the first constricted section 604, wherein the tapered section 603 has a diameter gradually decreased from the first diameter A to the second diameter B.
Preferably, the gas outlet orifice 60 is not physically connected to the burner venturi 70, allowing for flexibility and ease of maintenance.
The burner venturi 70 further comprises an air restrictor 71 mounted at an inlet end 704 thereof, configured to regulate air entering the burner venturi 70, and an outlet adaptor 72 mounted at an outlet end 705 thereof, configured to generate sufficient back pressure to maintain stable combustion. The air restrictor 71 and the outlet adaptor 72 each have a hollow cylindrical shape with an internal cavity.
The burner assembly 20 further comprises a pilot 80 and a pilot orifice 82 positioned in a gas line leading to the pilot 80. The pilot orifice 82 comprises, from an inlet end to an outlet end, a gas channel comprising at least one wide section (822 and 823) and an orifice hole 825, wherein the orifice hole 825 has a diameter smaller than that of the at least one wide section 822 and 823. Preferably, the orifice hole 825 has a diameter of about 1/40 to about 1/50 of the diameter of the at least one wide section 822 and 823.
In a preferred embodiment, the heat distribution assembly 10 comprises a radiant tube 11 with a proximal end 111 connected to the burner assembly 20.
Preferably, the burner assembly 20 is configured as a burner box divided into a sealed side 20 a and an unsealed side 20 b. The sealed side 20 a is fully closed for protecting critical gas train and electrical components. The unsealed side 20 b comprises openings for airflow and cooling.
The sealed side 20 a comprises a pilot safety control 40, wherein the pilot safety control 40 comprises a first valve 41 configured to receive high pressure gases from an external source, a second valve 42 configured to control flow of gas to the burner venturi 70 through the gas outlet orifice 60, a third valve 43 configured to control flow of gas to the pilot 80 through the pilot orifice 82, and a fourth valve 44 connect to a thermocouple that is configured to continuously monitors presence and stability of the pilot flame.
The sealed side 20 a may further comprise an auto reset 50 configured to automatically reset the heater unit assembly 1 after a temporary interruption or fault.
The unsealed side 20 b of the burner box 20 comprises the gas outlet orifice 60. The inlet end 704 of the burner venturi 70 is mounted in a side wall 211 of the burner box 20, and the remaining portion of the burner venturi 70 extends outwardly from the burner box 20 into the heat distribution assembly 10. The pilot 80 and the thermocouple 90 are arranged parallel to the burner venturi 70.
In a preferred embodiment, the heat distribution assembly 10 comprises a radiant tube 11 with a proximal end 111 connected to the side wall 211 of the burner box, the radiant tube 11 housing the burner venturi 70, the pilot 80, and the thermocouple 90 extending outwardly from the burner box 20. In one embodiment, the proximal end 111 of the radiant tube 11 is welded to an adaptor ring 26 that is mounted on an exterior surface of the side wall 211 of the burner box 20, with an insulator 27 positioned between the adaptor ring 26 and the side wall 20.
The objects and advantages of the invention will appear more fully from the following detailed description of the preferred embodiment of the invention made in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an exemplary tube heater 1 according to the present disclosure.

FIG. 2 is a back view of the tube heater 1.

FIG. 3 is a partial front view of the tube heater 1, showing the connection between the heat distribution assembly 10 and the burner box 20.

FIG. 4 is a front view of the internal arrangement of the burner box 20.

FIG. 5 is a top view of the internal arrangement of the burner box 20.

FIG. 6 is a perspective view of the sealed side 20 a of the burner box 20.

FIG. 7 is a front view of the unsealed side 20 b of the burner box 20.

FIG. 8 is a top view of the unsealed side 20 b of the burner box 20.

FIG. 9 is a front view showing the alignment of the gas outlet orifice 60 with the burner venturi 70, as positioned through the orifice to burner alignment 62 and the orifice plate 63.

FIG. 10 shows a front view of the gas outlet orifice 60 (upper) and a cross-sectional view taken along line A-A (lower).

FIG. 11 shows a front view of the burner venturi 70 (upper) and a cross-sectional view taken along line B-B (lower).

FIG. 12 shows a front view of the pilot orifice 82 (upper) and a cross-sectional view taken along line C-C (lower).

FIGS. 13-26 show exemplary designs of auxiliary components of the tube heater 1.

FIG. 13 shows a front view of the adaptor ring 26 (upper) and a perspective view showing weldment of the radiant tube 11 to the adaptor ring 26 (lower).

FIG. 14 shows a top view (upper), a front view (middle), and a cross-sectional view taken along line D-D (lower) of the shroud 12.

FIG. 15 shows a perspective (upper left) and a front view (lower left) of the end cap 13, and a perspective (upper right) and a front view (lower right) of the end cap 14.

FIG. 16 shows a perspective view (upper) and a top view (lower) of the turbulation strip 16.

FIG. 17 shows a top view (upper left), a front view (lower left), and a perspective view (right) of the wrapper 21.

FIG. 18 shows a top view (upper left), a side view (lower left), and a perspective view (right) of the inlet side panel 22.

FIG. 19 shows a top view (upper left), a front view (lower left), and a perspective view (right) of the control side panel 23.

FIG. 20 shows a perspective view (left), a side view (upper middle), a front view (lower middle), and a cross-sectional view taken along line E-E (right) of the heat shield 24.

FIG. 21 shows a tope view (upper left), a front view (lower left), a perspective view (upper right), and a back view (lower right) of the gas train bracket 25.

FIG. 22 shows a perspective view (left) and a front view (right) of the orifice to burner alignment 62.

FIG. 23 shows a perspective view (left), a side view (middle), and a front view (right) of the orifice plate 63.

FIG. 24 shows a perspective view (upper), a side view (lower left), and a front view (lower right) of the pilot bracket 28.

FIG. 25 shows a perspective view (left), a side view (middle), and a cross-sectional view taken along line F-F (right) of the air restrictor 71.

FIG. 26 shows a perspective view (upper left), a side view (lower left), a front view (upper right), and a cross-sectional view taken along line G-G (lower right) of the burner outlet adaptor 72.

DETAILED DESCRIPTION

Described herein is a naturally aspirated heater unit assembly, more specifically a tube heater utilizing high pressure gases, e.g., natural gas or liquid propane gas. The tube heater is designed to enhance combustion efficiency and minimize maintenance requirements. In one embodiment, the tube heater provided herein has a heating capacity of under 15,000 BTU/H.
Referring to FIGS. 1-26 , an exemplary radiant tube heater 1 according to the present disclosure comprises a heat distribution assembly 10 connected to a burner assembly arranged as a burner box 20. The heat distribution assembly 10 comprises a radiant tube 11 connected at its proximal end 111 to the burner box 20 (FIGS. 1-3 ). In the exemplary embodiment shown herein, the proximal end 111 of the radiant tube 11 is welded to an adaptor ring 26 as the adaptor ring 26 is mounted on the exterior surface of the side wall 211 of the burner box 20 (FIG. 3 ). An insulator 27 is placed between the adaptor ring 26 and the side wall 211 to minimize heat loss at the joint and prevent thermal damage of the components within the burner box 20 (FIG. 3 ). The heat distribution assembly 10 further comprises a shroud 12 that covers the radiant tube 11, an end cap 13 at a proximal end of the shroud 12, an end cap 14 at a distal end of the shroud 12, and a hanger 15 for hanging the tube heater 1 for use (FIGS. 1-2 ). An air turbulation strip 16 is optionally positioned within the radiant tube 11 to enhance heat transfer efficiency. Exemplary designs of the adaptor ring 26, shroud 12, end caps 13 and 14, and air turbulation strip 16 are shown in FIGS. 13-16 . It is noted that configuration of the heat distribution assembly 10 is not confined to the exemplary embodiment shown herein. Any heat distribution assembly designed for application in a heater unit, as known in the art, is considered suitable for use herein. This includes a range of configurations and construction materials.
The burner box 20 is designed for easy cleaning and protection of critical gas trains and electrical components. The burner box 20 is wrapped by a wrapper 21 covering the top, the bottom, and the side that is connected to the radiant tube 11, an inlet side panel 22 covering the front and the side facing away from the radiant tube 11, and a control side panel 23 covering the back of the burner box 20 (FIG. 1 ). A heat shield 24 divides the burner box 20 to a sealed side 20 a and an unsealed side 20 b (FIGS. 4-5 ). Specific designs of the wrapper 21, inlet side panel 22, control side panel 23, and heat shield 24 are shown in FIGS. 17-20 . However, the burner box 20 may be enclosed and divided by panels with various designs or configurations and is not limited to the exemplary wrapper and panels described herein.
The sealed side 20 a comprises components that provide electricity and safety controls for the tube heater 1. The arrangement keeps unwanted debris out and thus reduces maintenance requirement of the components. Referring to FIGS. 4-6 , the sealed side 20 a comprises a cord power 30 and corresponding circuits that provide electricity for the tube heater components, a pilot safety control 40 that monitors and controls gas flow to a burner venturi 70 and a pilot 80, and an auto reset 50 that automatically resets the system after a temporary interruption or fault. The components at the sealed side 20 a are supported by a gas train bracket 25, as illustrated with the specific design in FIG. 21 . The pilot safety control 40 comprises a first valve 41 configured to receive high pressure gases from an external source, a second valve 42 configured to control the flow of gas to the burner venturi 70 through a pipe 61 and a gas outlet orifice 60, a third valve 43 configured to control the flow of gas to the pilot 80 through a gas tube 81 and a pilot orifice 82, and a fourth valve 44 connected to a thermocouple 90 through a thread 91 for continuously monitoring the presence and stability of the pilot flame.
The unsealed side 20 b communicates with the external environment through openings in the wrapper 21, which allows for airflow and optimal cooling. Referring to FIGS. 4-5 and 7-9 , the unsealed side 20 b comprises a gas outlet orifice 60 that is positioned in the gas line leading to the burner venturi 70 and aligned with the burner venturi 70 by an orifice to burner alignment 62 coupled with an orifice plate 63 (FIG. 9 ). The gas outlet orifice 60 receives high pressure gas from the pilot safety control 40 through the valve 42 and the pipe 61, and regulates the flow of gases into the burner venturi 70. The orifice to burner alignment 62 is mounted on the interior surface of the side wall 211 of the wrapper 21 and holds an inlet end of the burner venturi 70 as it penetrates both the side wall 211 and the orifice to burner alignment 62. An outlet end of the burner venturi 70 is held by a pilot bracket 28 that is mounted on the exterior surface of the side wall 211. The orifice plate 63 is mounted to the orifice to burner alignment 62 and holds the gas outlet orifice 60 in place. The burner venturi 70 extends from the side wall 211 to the interior of the radiant tube 11. A pilot 80 and a thermocouple 90 are arranged parallel to the burner venturi 70 within the radiant tube 11 and held by the pilot bracket 28. The pilot 80 receives gas from the pilot safety control 40 through the valve 43 and the gas pipe 81. The pilot 80 comprises a pilot orifice 82 in the gas line that controls the flow of gas to the pilot. The thermocouple 90 communicates with the safety control 40 through the valve 44 and the thread 91. Specific designs of the orifice to burner alignment 62, orifice plate 63, and pilot bracket 28 are shown in FIGS. 22-24 .
Referring to FIG. 10 , a preferred embodiment of the gas outlet orifice 60 according to the present disclosure comprises, internally from an inlet end to an outlet end, a gas channel formed by a threaded section 601 that receives a threaded end of the pipe 61, a wide section 602 having a diameter A, a tapered section 603 having a diameter gradually decreased from the diameter A to a diameter B, a first constricted section 604 having a diameter B, and a second constricted section 605 having a diameter C. The exit diameter C is larger than the diameter B, but smaller than the diameter A. Preferably, diameter C is about 1.1 to about 1.6 times diameter B, and about 0.1 to about 0.2 times diameter A. However, ratios of diameters A, B, and C outside these ranges are also encompassed within this disclosure. The stepped configuration of the orifice containing the first constricted section 604 with diameter B and the second constricted section 605 with diameter C creates a pressure drop for the gas and transforms the high-pressure gas to a lower pressure. This leads to an optimum flame pattern, and it decreases the noise of the flame. In one embodiment, the pressure drop ratio from the first constructed section 604 to the second constricted section 605 is 1.425:1. The pressure drop of the fuel gas through the gas outlet orifice 60 is crucial to ensure that the gas is released at the correct velocity and mixes effectively with the air for combustion. Additionally, the configuration that the gas outlet orifice 60 is not physically connected to the burner venturi 70 allows for flexibility and ease of maintenance, as the gas outlet orifice 60 can be accessed and replaced without disassembling the entire burner assembly.
Referring to FIG. 11 , a preferred embodiment of the burner venturi 70 comprises, internally from an inlet end to an outlet end, a gas channel formed by an inlet portion 701, a throat portion 702, and an outlet portion 703. The narrowing of the throat portion 702 of the burner venturi 70 accelerates the flow of the gas through the constricted section, creating a low-pressure zone at the throat. This low-pressure area draws in surrounding air from the inlet portion 701, effectively mixing it with the fuel gas. An air restrictor 71 is mounted at the inlet end 704 of the burner venturi 70 (FIG. 9 ), for example, by threading into the threaded hole at the inlet end 704. The air restrictor 71 limits the incoming primary air and reduces the velocity of the flame for quieter operation. At the outlet end 705 of the burner venturi 70, a burner outlet adaptor 72 is mounted to the burner venturi 70 (FIG. 9 ), for example, by threading the threaded portion of the outlet end 705 into the threaded hole of the burner outlet adaptor 72. The burner outlet adaptor 72 generates sufficient back pressure to maintain strong combustion, prevent unplanned flameouts, and avoid backflash. The air restrictor 71 and the burner outlet adaptor 72 are designed to be paired with the burner venturi 70 to create complete naturally aspirated combustion. Specific configurations of the air restrictor 71 and the burner outlet adaptor 72 are shown in FIGS. 25-26 , each of which have a hollow cylindrical shape with an internal cavity for regulating gas/air flow.
Referring to FIG. 12 , a preferred embodiment of the pilot orifice 82 comprises an orifice hole 825 at the outlet end to reduce pressure of the gas from the gas tube 81, ensuring a continuous and controlled flame that is ready to ignite the main burner when needed. In the exemplary design shown in FIG. 12 , the pilot orifice 82 comprises, internally from the inlet end to the outlet end, a gas channel formed by a threaded section 821 that receives a threaded end of the gas tube 81, wide sections 822 and 823, and a tapered section 824, with each section having progressively smaller diameter leading to the diameter of the orifice hole 825. Preferably, the orifice hole 825 has a diameter of about 1/40 to 1/50 of the diameter of the wide sections 822 and 823. In one embodiment, the gas pressure drops 5 PSI through the pilot orifice 82 to the pilot burner at an approximately 8-14 in/wc operation.
The exemplary tube heater 1 as described herein can achieve a 30% reduction in gas consumption compared to the current brooder, making it more efficient while delivering a similar heat distribution. It can seamlessly replace existing high-pressure gas brooders due to its capability to operate at the same gas pressure requirements.
In the foregoing description, certain terms have been used for brevity, clarity, and understanding. No unnecessary limitations are to be inferred therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed. The different configurations and systems described herein may be used alone or in combination with other configurations and systems. It is to be expected that various equivalents, alternatives and modifications are possible within the scope of the foregoing description. Each limitation in the appended claims is intended to invoke interpretation under 35 U.S.C. § 112, sixth paragraph, only if the terms “means for” or “step for” are explicitly recited in the respective limitation.
While this disclosure may be embodied in many forms, what is described in detail herein is a specific preferred embodiment of the disclosure. The present disclosure is an exemplification of the principles of the disclosure and is not intended to limit the disclosure to the particular embodiments illustrated. It is to be understood that this disclosure is not limited to the particular examples, configurations, materials, and arrangements disclosed herein as such configurations, materials, and arrangements may vary somewhat.
As used herein, the singular forms “a,” “an,” and “the” include plural referents unless the content clearly dictates otherwise.
As used herein, the term “or” is an inclusive “or” operator and is equivalent to the term “and/or” unless the context clearly dictates otherwise.
Numerical ranges as used herein are intended to include every number and subset of numbers contained within that range, whether specifically disclosed or not. Further, these numerical ranges should be construed as providing support for a claim directed to any number or subset of numbers in that range. For example, a disclosure of from 1 to 10 should be construed as supporting a range of from 2 to 8, from 3 to 7, from 5 to 6, from 1 to 9, from 3.6 to 4.6, from 3.5 to 9.9, and so forth.
The systems of the present disclosure can comprise, consist of, or consist essentially of the essential elements and limitations described herein, as well as any additional or optional components, or limitations described herein or otherwise useful in the art. The disclosure provided herein suitably may be practiced in the absence of any element which is not specifically disclosed herein.

Claims

What is claimed is:

1. A heater unit assembly comprising:

a. a burner assembly configured to provide a flow of heated air, the burner assembly comprising a gas outlet orifice aligned with a burner venturi, wherein:

the gas outlet orifice is positioned in a gas line leading to the burner venturi;

the gas outlet orifice comprises, internally from an inlet end to an outlet end, a gas channel comprising a wide section having a first diameter, a first constricted section having a second diameter, and a second constricted section having a third diameter, wherein the third diameter is larger than the second diameter but smaller than the first diameter; and

the burner venturi comprises, internally from an inlet end to an outlet end, a gas channel comprising an inlet portion, a throat portion, and an outlet portion, wherein the throat portion is narrower than the inlet portion and the outlet portion; and

b. a heat distribution assembly connected to the burner assembly and configured to distribute the heat from the flow of heated air provided by the burner assembly.

2. The heater unit assembly of claim 1, wherein the third diameter is about 1.1 to about 1.6 times the second diameter, and about 0.1 to about 0.2 times the first diameter.

3. The heater unit assembly of claim 1, wherein the third diameter is about 1.425 times the second diameter.

4. The heater unit assembly of claim 1, wherein the gas channel of the gas outlet orifice further comprises a tapered section between the wide section and the first constricted section, wherein the tapered section has a diameter gradually decreased from the first diameter to the second diameter.

5. The heater unit assembly of claim 1, wherein the gas outlet orifice is not physically connected to the burner venturi.

6. The heater unit assembly of claim 1, wherein the burner venturi further comprises an air restrictor mounted at an inlet end thereof, configured to regulate air entering the burner venturi, and an outlet adaptor mounted at an outlet end thereof, configured to generate sufficient back pressure to maintain stable combustion, wherein the air restrictor and the outlet adaptor each have a hollow cylindrical shape with an internal cavity.

7. The heater unit assembly of claim 1, wherein the burner assembly further comprises a pilot and a pilot orifice positioned in a gas line leading to the pilot, wherein the pilot orifice comprises, from an inlet end to an outlet end, a gas channel comprising at least one wide section and an orifice hole, wherein the orifice hole has a diameter smaller than that of the at least one wide section.

8. The heater unit assembly of claim 7, wherein the orifice hole has a diameter of about 1/40 to about 1/50 of the diameter of the at least one wide section.

9. The heater unit assembly of claim 1, wherein the heat distribution assembly comprises a radiant tube with a proximal end connected to the burner assembly.

10. The heater unit assembly of claim 1, wherein the burner assembly is configured as a burner box divided into a sealed side and an unsealed side, wherein the sealed side is fully closed, and the unsealed side comprises openings for airflow and cooling.

11. The heater unit assembly of claim 10, wherein the sealed side of the burner box comprises a pilot safety control, wherein the pilot safety control comprises a first valve configured to receive high pressure gases from an external source, a second valve configured to control flow of gas to the burner venturi through the gas outlet orifice, a third valve configured to control flow of gas to the pilot through the pilot orifice, and a fourth valve connected to a thermocouple that is configured to continuously monitor presence and stability of the pilot flame.

12. The heater unit assembly of claim 10, wherein the sealed side of the burner box comprises an auto reset configured to automatically reset the heater unit assembly after a temporary interruption or fault.

13. The heater unit assembly of claim 11, wherein the unsealed side of the burner box comprises the gas outlet orifice.

14. The heater unit assembly of claim 13, wherein the inlet end of the burner venturi is mounted in a side wall of the burner box, and the remaining portion of the burner venturi extends outwardly from the burner box into the heat distribution assembly.

15. The heater unit assembly of claim 14, wherein the pilot and the thermocouple are arranged parallel to the burner venturi.

16. The heater unit assembly of claim 15, wherein the heat distribution assembly comprises a radiant tube with a proximal end connected to the side wall of the burner box, the radiant tube housing the burner venturi, pilot, and thermocouple extending outwardly from the burner box.

17. The heater unit assembly of claim 16, wherein the proximal end of the radiant tube is welded to an adaptor ring that is mounted on an exterior surface of the side wall of the burner box, with an insulator positioned between the adaptor ring and the side wall.