CA2823428A1

CA2823428A1 - A boiler

Info

Publication number: CA2823428A1
Application number: CA2823428A
Authority: CA
Inventors: Hongfeng Zhu; Zhuhong Wang
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-12-28
Filing date: 2010-12-28
Publication date: 2012-07-05
Also published as: US20130276721A1; WO2012088660A1

Abstract

A boiler includes a water tank (9), a smoke exhaust pipe (6), a combustion chamber (1) and a fuel supply device. A furnace (5) is provided in the water tank (9), and one end of the smoke exhaust pipe (6) is connected with the flue gas outlet of the furnace (5), while the other end passes through the furnace (5). The part of the smoke exhaust pipe (6) in the furnace (5) is spiral. The combustion chamber (1) is set at the bottom of the furnace (5) and communicated with the furnace (5), and the fuel supply device is connected with the fuel inlet of the combustion chamber (1). The invention improves the heat energy utilization of high temperature flue gas, and solves the problem of water pipe blockage caused by scale in the current boiler.

Description

A BOILER
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable STATEMENT REGARDING FEDERALLY SPONSORED
RESEARCH OR DEVELOPMENT
Not Applicable INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A
COMPACT DISC
Not Applicable BACKGROUND OF THE INVENTION
1. Field of the Invention The invention is in the field of heat exchange, and more particularly, is a boiler.

2. Description of Related Art Boilers are common appliances for heat change, which heat water contained in the boiler by burning of fuel. The heated water is usually used in many ways in life such as getting warm, bathing and drinking.
A method of working of a conventional boiler is usually like this: a spiral water pipe is provided in a hearth of a boiler. The water pipe is in communication with a tank of the boiler. In a process of heating, high temperature gas from combustion in the hearth heats the water pipe, and the water in the water pipe is then heated and driven to run into the tank of the boiler.
In the above mentioned method of heating, the high temperature gas moves upward in the hearth at a very high speed and quickly passes the water pipe and then exits the boiler. In a boiler with this working process, a time for the high temperature gas to heat the water pipe is very short. A large amount of gas exits the boiler after combustion in a very short time and the heat contained in the gas will not able to be completely absorbed. Heat energy is thus being wasted and a use ratio thereof is usually low.
At the same time, when the high temperature gas from the combustion in the hearth heats the water pipe, a layer of incrustation will form on an inner surface of the water pipe after a long time of working as the water pipe is directly heated. The incrustation will not only decrease a heat ratio to the water pipe, but also clog the water pipe, which enhance a malfunction ratio thereof.
BRIEF SUMMARY OF THE INVENTION
The main object of the invention is to provide a boiler which is able to increase a use ratio of heat energy of fuel therein and decrease a malfunction ratio thereof.
In order to accomplish the above object, the present invention provides a boiler having a tank, a hearth contained in the tank, a gas pipe having one end in communication with a gas exit of the hearth and the other end passing through the hearth, a combustor in communication with a bottom of the hearth, and a fuel supply device being connected to a fuel inlet of the combustor.
Preferably, a plurality of heat exchange fins is formed on a portion of the gas pipe in the tank.
Preferably, a dust collection box is provided at the end of the gas pipe passing through the tank, and at least one filter screen is disposed in the dust collection box.
Preferably, one heat insulation layer is provided round an outer surface of the tank.

Preferably, a plurality of air supply holes is defined in a wall of the hearth, an air supply chamber is formed on an outside surface of the hearth surrounding the plurality of air supply holes, and an air supply pipe is provided air communicating the air supply chamber.
Preferably, the air supply chamber is of a circular shape and the air supply holes are evenly disposed in the hearth.
Preferably, the combustor has a combustion chamber, an ash excretion roller and an ash excretion motor, an ignition bar being in a bottom of the combustion chamber, a plurality of air inlets being defined in the bottom near a fuel inlet of the combustion chamber, the ash excretion roller being disposed in the bottom near an ash outlet of the combustion chamber and rolling in a direction to the ash outlet, the ash excretion roller being of barrel shape having air vents defined in a wall thereof, an air supply chamber being disposed under the combustion chamber, the air supply chamber being in communication with the air inlets at the fuel inlet and the air vents in the ash excretion roller, an output of the ash excretion motor being connected to an axle of the ash excretion roller.
Preferably, the fuel supply device has a hopper, a rotor and a feed motor, a feed pipe being under the hopper and in communication with an opening in the hopper, the rotor being contained in the feed pipe and having a spiral sector formed thereon, the feed motor having an output being connected to the rotor.

Preferably, the hopper is of conical and the rotor is disposed under a bottom of the hopper having a smaller cross-sectional area.
Preferably, the boiler further has an ash tray under an outlet of the combustor.
These and other objectives, features, and advantages of the present invention will become apparent from the following detailed description, the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
Fig. 1 is a schematic top view of the preferred embodiment of the invention.
Fig. 2 is a right side view thereof.
Fig. 3 is a cross-sectional view along B-B in Fig. 1.
Fig. 4 is a cross-sectional view along A-A in Fig. 1.
Fig. 5 is a partial view thereof. And, Fig. 6 is another partial view thereof.
DETAILED DESCRIPTION OF THE INVENTION
The invention provides a boiler which is able to increase a use ratio of heat energy of fuel therein and decrease a malfunction ratio thereof.

With reference to Figs. 1 to 6, Fig. 1 is a schematic top view of the preferred embodiment of the invention. Fig. 2 is a right view thereof. Fig. 3 is a cross-sectional view along B-B
in Fig. 1. Fig. 4 is a cross-sectional view along A-A in Fig. I. Fig. 5 is a partial view thereof. And, Fig. 6 is another partial view thereof.
The boiler of the invention has a tank 9, a gas pipe 6, a hearth 5, a combustor 1, and a fuel supply device. The hearth 5 is disposed in the tank 9 and has a bottom in communication with the combustor 1. The combustor 1 is a place for the fuel to burn.
High temperature gas produced by the burning in the combustor 1 enters the hearth 5.
One end of the gas pipe 6 is in communication with a gas exit of the hearth 5, and the other end thereof passes through the hearth 5. A portion of the gas pipe 6 in the hearth 5 extends spirally.
The fuel supply device is for conveying fuel to the combustor 1 and is in communication with a fuel inlet of the combustor 1.
In the boiler of the invention, fuel is supplied to the combustor 1 by the fuel supply device. The high temperature gas produced by the burning in the combustor 1 enters the gas pipe 6 via the hearth 5. The portion of the gas pipe 6 in the hearth 5 extends spirally.
Water contained in the tank 9 is heated via the gas pipe 6. Gas exits the gas pipe 6 after heat is fully absorbed.

In the boiler of the invention, a way of heating is changed from a conventional type of "fire surrounding water" to a "water surrounding fire". The gas pipe 6 directing the high temperature gas therein passes through the tank 9, and the hearth 5 and the gas pipe 6 are disposed in the tank 9. All heat giving out from the hearth 5 and the gas pipe 6 is absorbed by the water contained in the tank 9. The portion of the gas pipe 6 in the hearth is spiral in order to increase a running distance of the gas in the gas pipe 6. A time for heat exchange between the gas in the gas pipe 6 and the water in the tank 9 is thus being increased. Heat in the high temperature gas is able to be absorbed fully and a heat energy use ratio is able to be increased. At the same time, since the "water surrounding fire" type of heating in which the gas pipe 6 passes through the tank 9, a clog of the water pipe by incrustation will no longer exist. A malfunction rate of the boiler is thus being decreased.
In the boiler of the invention, the portion of the gas pipe 6 in the tank 9 is a main part thereof for heating the water in the tank 9, and the portion extends in the tank 9 spirally.
The portion is able to extend in any pattern of spiral in the tank 9. More preferably, the portion of the gas pipe 6 in the tank 9 extends spirally round an outer surface of the hearth 5. This pattern of spiral is able to make a structure of the boiler of the invention more compact. As a more preferable resolution, a plurality of heat exchange fins or needles are formed on the portion of the gas pipe 6 in the tank 9. The heat exchange fins or needles are able to increase a contact area between the gas pipe 6 and water, which will increase heat exchange ratio and make more heat in the high temperature gas in the gas pipe 6 be absorbed.

In a working process of the boiler of the embodiment, the high temperature gas in the gas pipe 6 from the hearth 5 contains a lot of dust. In order to decrease the negative effect of the dust in the gas to atmosphere, a dust collection box 12 is provided at the end of the gas pipe 6 passing through the tank 9. At least one filter screen is disposed in the dust collection box 12. Dust is able to be filtrated to the dust collection box 12 when gas passes through the filter screen. A content of dust in an emission may be decreased. The dust in the dust collection box 12 is able to be cleaned termly when a certain amount is accumulated. An exhaust fan 121 is able to be disposed at an outlet of the dust collection box 12. For a better effect of filtering, more layers of filter screens can be disposed in the dust collection box 12. Preferably, the layers of the filter screen are placed parallel with respect to each other. And more preferably, the layers of the filter screen are placed parallel and staggerly, in a distal and a proximal end of the dust collection box 12.
In the above mentioned boiler, when the gas pipe 6 heats the water in the tank 9, a body of the tank 9 may lose some heat. To decrease the heat dissipation of the body of the tank 9, one heat insulation layer may be provided round an outer surface of the tank 9. A heat dissipation ratio may be diminished by the heat insulation layer. A water inlet and a water outlet are provided in the body of the tank 9 respectively for water injection and drainage.
In the working process of above boiler, the high temperature inevitably contains a large amount of incompletely burn gas such as carbon monoxide. Such gas has not been combusted completely and will cause not only insufficient use of the heat energy from combustion but also atmosphere pollution. For a resolution, a plurality of air supply holes 52 is defined in a wall of the hearth 5. An air supply chamber 51 is formed on an outside surface of the hearth 5 surrounding the plurality of air supply holes 52. An air supply pipe 8 is provided air communicating an air inlet of the air supply chamber 51. Air is supplied into the hearth 5 and then mixed with the high temperature therein. In a high temperature circumstance, plenty of air helps the uncompleted burn gas combust at a second time, which brings a more completed combustion. For a more preferably resolution, the air supply chamber 51 of the hearth 5 is of a circular shape and the air supply holes 52 are evenly disposed in the hearth 5. This feature is able to ensure air be supplied into the hearth 5 in various direction via the air supply hole 52 in the second time air supply. An effect of air supply may be improved.
In the above boiler, the combustor 1 is a place where burning occurs. The combustor 1 can be of any type. The embodiment provides a combustor 1 having a combustion chamber, an ash excretion roller 101 and an ash excretion motor 10.
An ignition bar 11 is provided in a bottom of the combustion chamber. A
plurality of air inlets are defined in the bottom near a fuel inlet of the combustion chamber.
The ash excretion roller 101 is disposed in the bottom near an ash outlet of the combustion chamber and rolls in a direction to the ash outlet. The ash excretion roller 101 is of barrel shape having air vents defined in a wall thereof.

An air supply chamber 102 is disposed under the combustion chamber. The air supply chamber 102 is in communication with the air inlets at the fuel inlet and the air vents in the ash excretion roller 101.
An output of the ash excretion motor 10 is connected to an axle of the ash excretion roller 101. The ash excretion roller 101 is driven to rotate by the ash excretion motor 10.
In working of the boiler 1, fuel enters the combustion chamber via the fuel inlet and air is supplied into the combustion chamber through the air supply chamber 102. As the fuel burns, ash is pushed to exit by the rotation of the ash excretion roller 101.
Ash is able to excrete at all times from the combustion chamber, and scorification caused by accumulation of ash after combustion will be able to be avoided.
For complete burning of the fuel before being excreted by the ash excretion roller 101, the above ash excretion motor 10 may be a batch type motor and be controlled by an electric control box 13 provided on the boiler 1.
The fuel supplied by the fuel supply device to the combustor 1 in the invention can be various type and way of conveying. In this embodiment, the fuel supply device has a hopper 3, a rotor 21, and a feed motor 4.

A feed pipe 2 is provided under the hopper 3 and in communication with an opening in the hopper 3. The rotor 21 is contained in the feed pipe 2. A spiral sector is formed on the rotor 21.
An output of the feed motor 4 is connected to the rotor 21.
In the working of the fuel supply device, the rotor 21 is driven to rotate by the feed motor 4 and the fuel in the hopper 3 will be conveyed to the combustor 1 under a push of the spiral sector through the feed pipe 2. Fuel feeding is thus being automated.
For sufficient time for complete burning of the fuel after entering the combustor 1, the feed motor 4 may be a batch type motor and be controlled by the electric control box 13 provided on the boiler 1.
The hopper 3 is a part for fuel storage. For smoother moving of fuel, the hopper 3 is of conical shape and the rotor 21 is disposed under a bottom thereof having a smaller cross-sectional area. In the process of fuel feeding, subsequent fuel automatically drops to the opening of the hopper 3 and is conveyed by the rotor 21.
In this embodiment of the boiler, an ash tray 7 is provided under the outlet of the combustor 1. Ash produced by the fuel after combustion enters the ash tray 7 and is collected thereby.

From above description, it is seen that the objects of the present invention have been fully and effectively accomplished. Embodiment of the invention has been shown and described for the purposes of illustrating the functional and structural principles of the present invention and is subject to change without departure from the invention's principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.

Claims

1. A boiler comprising:
a tank, a hearth contained in said tank, a gas pipe having one end in communication with a gas exit of said hearth and the other end passing through said hearth, a combustor in communication with a bottom of said hearth, and, a fuel supply device being connected to a fuel inlet of said combustor.

2. The boiler as claimed in claim 1, wherein a plurality of heat exchange fins is formed on a portion of said gas pipe in said tank.

3. The boiler as claimed in claim 2, wherein a dust collection box is provided at said end of said gas pipe passing through said tank, and at least one filter screen is disposed in said dust collection box.

4. The boiler as claimed in claim 3, wherein one heat insulation layer is provided round an outer surface of said tank.

5. The boiler as claimed in claim 1, wherein a plurality of air supply holes is defined in a wall of said hearth, an air supply chamber is formed on an outside surface of said hearth surrounding said plurality of air supply holes, and an air supply pipe is provided air communicating said air supply chamber.

6. The boiler as claimed in claim 5, wherein said air supply chamber is of a circular shape and said air supply holes are evenly disposed in said hearth.

7. The boiler as claimed in claim 1, wherein said combustor has a combustion chamber, an ash excretion roller and an ash excretion motor, an ignition bar being in a bottom of said combustion chamber, a plurality of air inlets being defined in the bottom near a fuel inlet of said combustion chamber, said ash excretion roller being disposed in said bottom near an ash outlet of said combustion chamber and rolling in a direction to said ash outlet, said ash excretion roller being of barrel shape having air vents defined in a wall thereof, an air supply chamber being disposed under said combustion chamber, said air supply chamber being in communication with said air inlets at said fuel inlet and said air vents in said ash excretion roller, an output of said ash excretion motor being connected to an axle of the ash excretion roller.

8. The boiler as claimed in claim 7, wherein said fuel supply device has a hopper, a rotor and a feed motor, a feed pipe being under said hopper and in communication with an opening in said hopper, said rotor being contained in said feed pipe and having a spiral sector formed thereon, said feed motor having an output being connected to said rotor.

9. The boiler as claimed in claim 8, wherein said hopper is of conical and said rotor is disposed under a bottom of the hopper having a smaller cross-sectional area.

10. The boiler as claimed in claim 1, wherein the boiler further has an ash tray under an outlet of said combustor.