JPS5896940A - Fan and furnace combined - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a stream of hot air, particularly, but not exclusively, for drying grain or other crops in a grain dryer. Concerning the combined fan and furnace used to produce

Conventional grain dryers, when used, are connected directly or the furnace is of the J type or the suction type, or is operated as a "blow" or suction furnace. (depending on the type of duct with a fan upstream or downstream of the furnace)
I have been using separately made furnaces and fans that are separated by K. In "blowing" furnaces, the outlet of the fan housing is connected to the air intake of the furnace, and in suction furnaces, the outlet of the combustion chamber of the furnace is connected to the inlet of the fan housing.

In a "blowout" furnace, if the furnace is connected downstream of the fan, the air is expanded by the heat of combustion after passing through the fan, so if the furnace is connected upstream of the fan, the air is expanded by the heat of combustion. It would take a relatively small number of fans to obtain the same amount of hot air as in the case of K. However, such devices have the disadvantage that it is difficult to mix the hot gas and air well and they require the use of baffles that create back pressures that increase the load on the fan and reduce flow rates.

In suction furnaces, if the furnace is connected upstream of the fan, the mixing of the hot gases from the furnace with the air stream is improved because mixing occurs in the turbulent zone between or near the fan blades. .

The burners are also more accessible than those of "blow-off" furnaces.

The object of the present invention is to provide a combined fan and furnace which achieves the advantages of each of the known devices mentioned above and which solves the problem of K achieving sufficient mixing of combustion gases and air.

According to the present invention, a combined fan and furnace includes a fan housing, an impeller disposed within the fan housing, and an opening at the downstream end, with air flowing directly into the fan housing near the impeller outlet. This is similar to a tubular combustion chamber installed like this.

The furnace can have a liquid burner or a gas burner, for example for burning oil, liquid gas or gaseous fuel, the combustion chamber being located upstream of the point where the open downstream end of the combustion chamber communicates with the outlet of the impeller. One area of the fan housing has an air intake for combustion that is inclined.

The fan housing also includes at least one baffle plate located downstream of the open downstream end of the combustion chamber for redirecting the combined flow of hot gas and airflow from the impeller. You may. For example, the combined flow can be redirected so that it does not directly impinge on the fan housing or the outlet ducts connected thereto.

The impeller is preferably a double inward flow centrifugal rotor, but may also be a single inward flow centrifugal type, an outward flow centrifugal rotor or an axial flow rotor.

BRIEF DESCRIPTION OF THE DRAWINGS A combined fan and furnace according to the invention, in particular for a grain dryer, will be described by way of example with reference to the accompanying drawings.

The fan has two inward-flow centrifugal impellers 2 with a pair of air intakes 3 at each end of the impeller shaft and communicating with the outside air.The 0 impeller is similar to Uzing 1.Using 1 The mounting on the outside is rotated by a piezoelectric motor 4. Alternatively, the impeller may be driven by an internal combustion engine or from the transmission shaft of a toshictor or other vehicle. The impeller 2 has a downwardly directed outlet opening into the interior of the housing 1 at 5 (see FIG. 2). of·
The housing 1 has a flanged opening at 6 to which a flue mounting plate 7 is bolted in a sealing manner. The mounting plate 7 has a smoke pipe 8 or an open combustion chamber attached thereto;
When the mounting plate 7 is in place, the inner open end of the flue 8 has an oil-fired burner 10 surrounded by a baffle 9 below the outlet from the impeller 2. Burner 1
0 is ignited by the electrode 11 provided on the mounting plate 7,
If electricity cannot be supplied, an ignition hole with a cover plate that can be rotated can be provided on the mounting plate 7 in place of the electrode. Insert a movable torch igniter through the ignition hole. The mounting plate 7 may also be provided with a phototube ignition failure indicator 12 or an equivalent mechanical device in case of no electricity supply;
It is located on the outside of the building, so it can be easily approached.

Located between the flue pipe 8 and the mounting plate 70, it is located on the flue pipe 8 downstream of the flue pipe 8 at a distance from the mounting plate 7, and is spaced upstream from the point where the downstream end of the smoke pipe 8 communicates with the interior 5 of the fan housing 1. 2 which communicates with the inside of the housing 1 at the
Combustion air can enter the upstream end of the smoke pipe 8 in the vicinity of the conical baffle 9 through the air outlet 13 . Together, the holes 13 create a venturi effect to ensure complete combustion within the flue 8. The combustion gas emerges from the downstream end of the smoke pipe 8 and enters the interior 5 of the fan housing 1 where it mixes with the hot air discharged into the interior 5 of the fan housing 1 by the impeller 2. Immediately downstream of the end of the flue 8 is a baffle plate 14 which prevents hot gas and hot air from impinging on the base of the fan housing 1. The stream of hot air is then directed through a suitable dust to the required location to dry grain or other crops.

The combined fan and furnace shown is particularly for use in continuous flow grain dryers in which hot air is passed through an armored floor. In order to distribute hot air uniformly across the width of the floor, a fishmonger-shaped duct adapter 15 with a narrow outlet at 16 is bolted to the 7 flange of the outlet of the fan housing 1.

The combined fan and furnace provided and illustrated by the present invention achieves the advantages of both of the above-described arrangements in which the furnace and fan are separate, but also allows the air discharged from the impeller 2 in the fan housing 1 to be Since the combustion gas is directly discharged from the smoke pipe 8, the advantages of the "blowing steam" type furnace over the suction type furnace described above are maintained. Combined fans and furnaces have been designed primarily for continuous flow, armored floor grain driers and have also been found to be very effective as far as energy conversion is concerned. The power required for the motor 4 is reduced by 50 tns compared to a separate fan and furnace of the suction type as a result of the expansion of the air in the housing 1 in the region 5 downstream of the impeller 2. Another reason for this reduction in the power required is that the impeller used is of the double inward flow centrifugal type;
This means that smaller diameter impellers can be used compared to single-flow impellers, which require a higher starting torque due to their moment of inertia. However, if such a compact design is not required, a single-flow impeller can be used.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view of the combined fan and furnace. FIG. 2 is a cross-sectional view along the line in the direction of arrow i in FIG. 1... Housing 2... Impeller 7
......Mounting plate 8...-...Smoke pipe 10
・・・－・・・Patent attorney representing Barna Tsunekazu Kojima

Claims (1)

[Claims] 1. A fan housing (1) characterized in that the combustion chamber is installed so as to blow air directly into the fan housing (1-5) near the air outlet of the impeller. , an impeller arranged in its fan housing (1), and a tubular combustion chamber (8) which is open at its downstream end. 2. At least four baffles (14) are provided at the open downstream end of the combustion chamber (8) to redirect the combined flow of hot gas and airflow from the impeller (2) in a fixed direction. The combined fan and furnace of claim 1, wherein the combined fan and furnace is positioned downstream of the furnace.